Study on the Catalytic Reaction of Iso-butyl Mercaptan over HZSM-5 Zeolites in the Presence of Mechanol
The catalytic desulfurization conversion and mechanism of iso-butyl mercaptan as probe molecules over HZSM-5 zeolites have been studied in a fixed-bed micro-reactor.Iso-butyl mercaptan was easily thermally transformed to yield hydrogen sulfide, the thermal conversion was perfect under the condition of more than 400℃. The course of thermal reaction for iso-butyl mercaptan is free radical mechanism.Mercaptan over HZSM-5 zeolite strong magnets catalysts was comparatively easily transformed to yield hydrogen sulfide. Iso-butyl mercaptan may be full transformed while the reaction temperature got up to 300℃.They showed higher cracking conversion of iso-butyl mercaptan over the Ce-modified or La-modified HZSM-5 zeolites than one over parent HZSM-5 zeolites. The transformation mechanism of mercaptan was carbenium ion mechanism.Alcohol-type substances especially methanol had not only certain polarity, but also higher reaction activity, they were usually as reaction assist to accelerate the reaction. The catalytic transformation pathway could be http://www.chinamagnets.biz/ changed to decrease the yield of hydrogen sulfide and yielded methyl–contained sulfides such as methyl mercaptan, dimethyl sulfide and dimethyl disulfide, but overage concentration of methanol would holdback the transformation of iso-butyl mercaptan. The transformation of iso-butyl mercaptan was favorable if the volume ratio of methanol and benzene was 0.2.
2012年7月31日星期二
Synthesis and Characteristics of BaCe0.9-xZrxM0.1O3-δ (M=Gd、Nd) Proton Conductors
Synthesis and Characteristics of BaCe0.9-xZrxM0.1O3-δ (M=Gd、Nd) Proton Conductors
Since Iwahara et al. first reported the proton conductivity of a perovskite type Y doped SrCeO3 solid solution in 1981, interests in this type of materials have remained high due to the possibility of using them as solid electrolytes in electrochemical devices such as fuel cells, hydrogen separation, gas sensors, ammonia synthesis, et al.. At present rare earth doped BaCeO3 exhibit the best proton conductivity. However, BaCeO3 based materials will decompose in CO2 rare earth magnets atmosphere. BaZrO3 based materials are more stable in CO2 atmosphere, but their sintering temperature is very high(>1600℃).In this thesis, an investigation on the synthesis and measurement of proton conductivity of mixed BaCeO3 and BaZrO3 based ceramics has been carried out. The designed solid electrolyte ceramic compositions are BaCe0.9-xZrxM0.1O3-δ (x=0.1, 0.2, 0.4; M=Gd, Nd).
The solid electrolytes were synthesized by Pechini method. Dry powders were calcined at 1100℃. Pellet samples were prepared by first pressed the powders and then sintered at 1450℃. Powder samples or pellet samples were characterization by TG-DTA, XRD, SEM and AC impedance spectroscopy.The XRD results shows that perfect perovskite phases were synthesized by calcined the dried powders at 110℃. The densities of sintered ceramic pellet samples are greater than 93%of their theoretical densities by sintering at 1450℃. SEM shows the dense microstructure of the ceramic samples. AC impedance measurements reveal that the samples have http://www.chinamagnets.biz/ good proton conduction in moist air atmosphere. Gd doped solid electrolyte BaCe0.8Zr0.1Gd0.1O3-δ has higher conductivity than that of Nd doped solid electrolyte BaCe0.8Zr0.1Nd0.1O3-δ.
Since Iwahara et al. first reported the proton conductivity of a perovskite type Y doped SrCeO3 solid solution in 1981, interests in this type of materials have remained high due to the possibility of using them as solid electrolytes in electrochemical devices such as fuel cells, hydrogen separation, gas sensors, ammonia synthesis, et al.. At present rare earth doped BaCeO3 exhibit the best proton conductivity. However, BaCeO3 based materials will decompose in CO2 rare earth magnets atmosphere. BaZrO3 based materials are more stable in CO2 atmosphere, but their sintering temperature is very high(>1600℃).In this thesis, an investigation on the synthesis and measurement of proton conductivity of mixed BaCeO3 and BaZrO3 based ceramics has been carried out. The designed solid electrolyte ceramic compositions are BaCe0.9-xZrxM0.1O3-δ (x=0.1, 0.2, 0.4; M=Gd, Nd).
The solid electrolytes were synthesized by Pechini method. Dry powders were calcined at 1100℃. Pellet samples were prepared by first pressed the powders and then sintered at 1450℃. Powder samples or pellet samples were characterization by TG-DTA, XRD, SEM and AC impedance spectroscopy.The XRD results shows that perfect perovskite phases were synthesized by calcined the dried powders at 110℃. The densities of sintered ceramic pellet samples are greater than 93%of their theoretical densities by sintering at 1450℃. SEM shows the dense microstructure of the ceramic samples. AC impedance measurements reveal that the samples have http://www.chinamagnets.biz/ good proton conduction in moist air atmosphere. Gd doped solid electrolyte BaCe0.8Zr0.1Gd0.1O3-δ has higher conductivity than that of Nd doped solid electrolyte BaCe0.8Zr0.1Nd0.1O3-δ.
Hydrothermal Preparation and Physical Properties Study of Titanate Nanotube Doped with Ions
Hydrothermal Preparation and Physical Properties Study of Titanate Nanotube Doped with Ions
Titanate nanotube is a novel nanotube material that is prepared by the nano-powder precursor of TiO2. This kind of nanotube material will be endowed with novel properties by doped with magnetic ions or luminescience ions. The potential applications will also be putted to it.In this paper, the preparation and physical and chemical properties of titanate nanotube undoped and doped with ions were carried out. Some innovative results were obtained. They are shown as following:(1) Preparation and characters of titanate nanotubeTaking pure anatase TiO2 nano-particles as precursor, titanate nanotubes were synthesized by hydrothermal method. The microstructure and formation mechanism have been studied by many means of characterization, such as, Scan Electron Ring neodymium magnet Microscope, High-Resolution Transmission Electron Micrographs, Powder X-ray Diffraction, BET surface area analyse and so on. The results of research show that titanate nanotubes have muti-layer structure with the open end, inner diameter is about 6nm, outer diameter is 8 to 10 nm and the length is about 500nm. Besides, titanate nanotubes have larger surface area than TiO2 nano-particle, which is promising as high quality catalyzer or catalyzer carrier.(2) The thermal stability of titanate nanotubeTreatment of high temperature will bring into big changes to structures of titanate nanotubes. When the temperature below 250℃, the nanotube structure could be kept; after calcined at 350℃, the interlayer spacing decreased rapidly, meanwhile partial of the nanotube structure were destroyed markedly and the titanate phase was transformed into anatase-type TiO2;
when the temperature excessed 450℃, the tubular structures were destroyed completely and the structure changed into anatase-typed TiO2.(3) Study on preparation and magnetic property of titanate nanotube doped with magnetic ionsIn this paper, titanate nanotubes doped with magnetic ions (Fe3+、Ni2+、Mn2+) were synthesized by hydrothermal treatment of pure anatase TiO2 powders in concentrated NaOH solution. In this process, preparation of nanotubes is synchronously with doping magnetic ions. Magnetic properties of titanate nanotubes doped with Fe3+、Ni2+、Mn2+ ions were studied using a superconducting quantum interference device (SQUID) magnetometer. The magnetization versus the applied field curves (M versus H) of Fe3+、Ni2+、Mn2+ doped titanate nanotubes at 300 K show that the almost linear curve pass the origin point and the http://www.chinamagnets.biz/ slope is plus. The temperature dependence of magnetization (M versus T) in an applied field of 0.2 Tesla show that the value of M decrease sharply along with the increases of the temperature at low temperature, when the temperature is above 25K, the value of M changes slowly along with the increases of the temperature. Furthermore, the saturated magnetization (Ms) of titanate nanotube is so small. All of these results indicated that titanate nanotubes doped with Fe3+, or Ni2+, or Mn2+ ions demonstrates a paramagnetic behavior at room temperature.(4) Study on preparation and photoluminescence property of titanate nanotube doped with rare earth ionsTitanate nanotubes doped with Eu3+ or Tb3+ were obtained by hydrothermal treatment of pure anatase TiO2 powders in concentrated NaOH solution. The photoluminescence property of titanate nanotube doped with Eu3+ or Tb3+ were measured on a modular double grating excitation spectrofluorimeter with a TRIAX 320 emission monochromator. The results show that titanate nanotubes doped with Eu3+ or Tb3+ are optically active at room temperature. Both spectras are composed of a series of straight lines ascribed to Tb3+ and Eu3+ intra- transitions. Besides, the abnormal higher value of the fwhm0-0 indicates that the Eu3+ doped titanate nanotube has at least two distinct Eu3+ local coordination sites.
Titanate nanotube is a novel nanotube material that is prepared by the nano-powder precursor of TiO2. This kind of nanotube material will be endowed with novel properties by doped with magnetic ions or luminescience ions. The potential applications will also be putted to it.In this paper, the preparation and physical and chemical properties of titanate nanotube undoped and doped with ions were carried out. Some innovative results were obtained. They are shown as following:(1) Preparation and characters of titanate nanotubeTaking pure anatase TiO2 nano-particles as precursor, titanate nanotubes were synthesized by hydrothermal method. The microstructure and formation mechanism have been studied by many means of characterization, such as, Scan Electron Ring neodymium magnet Microscope, High-Resolution Transmission Electron Micrographs, Powder X-ray Diffraction, BET surface area analyse and so on. The results of research show that titanate nanotubes have muti-layer structure with the open end, inner diameter is about 6nm, outer diameter is 8 to 10 nm and the length is about 500nm. Besides, titanate nanotubes have larger surface area than TiO2 nano-particle, which is promising as high quality catalyzer or catalyzer carrier.(2) The thermal stability of titanate nanotubeTreatment of high temperature will bring into big changes to structures of titanate nanotubes. When the temperature below 250℃, the nanotube structure could be kept; after calcined at 350℃, the interlayer spacing decreased rapidly, meanwhile partial of the nanotube structure were destroyed markedly and the titanate phase was transformed into anatase-type TiO2;
when the temperature excessed 450℃, the tubular structures were destroyed completely and the structure changed into anatase-typed TiO2.(3) Study on preparation and magnetic property of titanate nanotube doped with magnetic ionsIn this paper, titanate nanotubes doped with magnetic ions (Fe3+、Ni2+、Mn2+) were synthesized by hydrothermal treatment of pure anatase TiO2 powders in concentrated NaOH solution. In this process, preparation of nanotubes is synchronously with doping magnetic ions. Magnetic properties of titanate nanotubes doped with Fe3+、Ni2+、Mn2+ ions were studied using a superconducting quantum interference device (SQUID) magnetometer. The magnetization versus the applied field curves (M versus H) of Fe3+、Ni2+、Mn2+ doped titanate nanotubes at 300 K show that the almost linear curve pass the origin point and the http://www.chinamagnets.biz/ slope is plus. The temperature dependence of magnetization (M versus T) in an applied field of 0.2 Tesla show that the value of M decrease sharply along with the increases of the temperature at low temperature, when the temperature is above 25K, the value of M changes slowly along with the increases of the temperature. Furthermore, the saturated magnetization (Ms) of titanate nanotube is so small. All of these results indicated that titanate nanotubes doped with Fe3+, or Ni2+, or Mn2+ ions demonstrates a paramagnetic behavior at room temperature.(4) Study on preparation and photoluminescence property of titanate nanotube doped with rare earth ionsTitanate nanotubes doped with Eu3+ or Tb3+ were obtained by hydrothermal treatment of pure anatase TiO2 powders in concentrated NaOH solution. The photoluminescence property of titanate nanotube doped with Eu3+ or Tb3+ were measured on a modular double grating excitation spectrofluorimeter with a TRIAX 320 emission monochromator. The results show that titanate nanotubes doped with Eu3+ or Tb3+ are optically active at room temperature. Both spectras are composed of a series of straight lines ascribed to Tb3+ and Eu3+ intra- transitions. Besides, the abnormal higher value of the fwhm0-0 indicates that the Eu3+ doped titanate nanotube has at least two distinct Eu3+ local coordination sites.
Combustion Synthesis Europium Ions (Eu～(2+)) Doped Alkaline Earth Aluminates Persistent Luminescence Phosphor and Their Optical Properties
Combustion Synthesis Europium Ions (Eu～(2+)) Doped Alkaline Earth Aluminates Persistent Luminescence Phosphor and Their Optical Properties
Photoluminescent material with long persistent luminescence is a kind of energy storage material that can absorb both the ultraviolet (UV) and visible lights from the sunlight and gradually release the energy in the darkness at a certain wavelength. The photoluminescence at the violet–yellow visible region of divalent europium ions (Eu2+) doped alkaline earth aluminates MAl2O4:Eu2+ (M = Ca, Sr, Ba) phosphor have been widely studied because they have good luminescent properties, such as high initial luminescent, intensity, long lasting time, suitable emitting color and chemical stability, which resulted in an unexpectedly large field of applications, such as luminous Cylinder neodymium magnet paints in highway, airport, buildings and ceramics products.The solid-state reaction process has been used intensively for phosphor synthesis, but this process often results in poor homogeneity and requires high calcinating temperature. Furthermore, the grain size of phosphor powders prepared through solid-state reaction method is in several tens of micrometers. Phosphors of small particles must be obtained by grinding the larger phosphor particles. Those processes easily introduce additional defects and greatly reduce luminescence efficiency. With the development of scientific technologies on materials, several chemical synthesis techniques, such as co-precipitation, sol–gel, microwave and combustion synthesis methods have been applied to prepare the rare earth ions activation alkaline earth aluminate and/or its phosphors. All of these methods were conducted in liquid phases so that each component can be accurately controlled and uniformly mixed. The combustion process to prepare the precursor powders, however, is very facile and only takes a few minutes, which has been extensively applied to the preparation of various oxide materials. This synthesis technique makes use of the heat energy liberated by the redox exothermic reaction at a relative low igniting temperature between metal nitrates and urea or other fuels. Furthermore, the process is also safe, instantaneous and energy saving.In this dissertation, Sr4Al14O25:Eu2+,
Dy3+, CaAl2O4:Eu2+,Nd3+ and SrAl2O4:Eu2+,Dy3+,Ho3+ phosphor with high brightness and long persistent luminescence was synthesized by combustion method. X-ray diffractometer (XRD), transmission electron microscope (TEM), luminescence spectrophotometer and brightness meter were used to analyze and measure the crystal structure, morphology, excitation and emission spectra, and long persistent decay curve of the phosphor, respectively, the luminescence mechanism was also discussed.The master work showed that:1. The Sr4Al14O25:Eu2+,Dy3+ http://www.chinamagnets.biz/ phosphor nanoparticles were synthesized at the first time by combustion synthesis processing, along with heating the precursor powder at 1300℃in a protective atmosphere of N2. Analytical results showed that the nanometer phosphors have pure monoclinic Sr4Al14O25 phase, with the average particles size in the range of 20–40 nm. Compared with the solid-state reaction method, the blue shifts of main peaks of emission of the nanometer phosphors occur and the particles size are tinier.2. The synthesis technology of Sr4Al14O25:Eu2+,Dy3+ long persistent phosphor was optimization using the orthogonal design method. The test results indicate that by correct selection of the operating parameters the better Sr4Al14O25:Eu2+,Dy3+ long persistent phosphor can be obtained through the combustion process.3. Eu2+, Nd3+ co-doped calcium aluminate persistent luminescence was prepared by the combustion method. The luminescent properties of CaAl2O4-based luminescent materials have been studied systematically.4. Eu2+,Dy3+,Ho3+co-doped strontium aluminate with high brightness and long persistent luminescence were prepared at the first time by the combustion method at 600℃. The decay time of the persistence indicated that the persistent luminescence phosphor of SrAl2O4:Eu2+,Dy3+,Ho3+ have better phosphorescence than the tradition phosphor of SrAl2O4:Eu2+,Dy3+.
Photoluminescent material with long persistent luminescence is a kind of energy storage material that can absorb both the ultraviolet (UV) and visible lights from the sunlight and gradually release the energy in the darkness at a certain wavelength. The photoluminescence at the violet–yellow visible region of divalent europium ions (Eu2+) doped alkaline earth aluminates MAl2O4:Eu2+ (M = Ca, Sr, Ba) phosphor have been widely studied because they have good luminescent properties, such as high initial luminescent, intensity, long lasting time, suitable emitting color and chemical stability, which resulted in an unexpectedly large field of applications, such as luminous Cylinder neodymium magnet paints in highway, airport, buildings and ceramics products.The solid-state reaction process has been used intensively for phosphor synthesis, but this process often results in poor homogeneity and requires high calcinating temperature. Furthermore, the grain size of phosphor powders prepared through solid-state reaction method is in several tens of micrometers. Phosphors of small particles must be obtained by grinding the larger phosphor particles. Those processes easily introduce additional defects and greatly reduce luminescence efficiency. With the development of scientific technologies on materials, several chemical synthesis techniques, such as co-precipitation, sol–gel, microwave and combustion synthesis methods have been applied to prepare the rare earth ions activation alkaline earth aluminate and/or its phosphors. All of these methods were conducted in liquid phases so that each component can be accurately controlled and uniformly mixed. The combustion process to prepare the precursor powders, however, is very facile and only takes a few minutes, which has been extensively applied to the preparation of various oxide materials. This synthesis technique makes use of the heat energy liberated by the redox exothermic reaction at a relative low igniting temperature between metal nitrates and urea or other fuels. Furthermore, the process is also safe, instantaneous and energy saving.In this dissertation, Sr4Al14O25:Eu2+,
Dy3+, CaAl2O4:Eu2+,Nd3+ and SrAl2O4:Eu2+,Dy3+,Ho3+ phosphor with high brightness and long persistent luminescence was synthesized by combustion method. X-ray diffractometer (XRD), transmission electron microscope (TEM), luminescence spectrophotometer and brightness meter were used to analyze and measure the crystal structure, morphology, excitation and emission spectra, and long persistent decay curve of the phosphor, respectively, the luminescence mechanism was also discussed.The master work showed that:1. The Sr4Al14O25:Eu2+,Dy3+ http://www.chinamagnets.biz/ phosphor nanoparticles were synthesized at the first time by combustion synthesis processing, along with heating the precursor powder at 1300℃in a protective atmosphere of N2. Analytical results showed that the nanometer phosphors have pure monoclinic Sr4Al14O25 phase, with the average particles size in the range of 20–40 nm. Compared with the solid-state reaction method, the blue shifts of main peaks of emission of the nanometer phosphors occur and the particles size are tinier.2. The synthesis technology of Sr4Al14O25:Eu2+,Dy3+ long persistent phosphor was optimization using the orthogonal design method. The test results indicate that by correct selection of the operating parameters the better Sr4Al14O25:Eu2+,Dy3+ long persistent phosphor can be obtained through the combustion process.3. Eu2+, Nd3+ co-doped calcium aluminate persistent luminescence was prepared by the combustion method. The luminescent properties of CaAl2O4-based luminescent materials have been studied systematically.4. Eu2+,Dy3+,Ho3+co-doped strontium aluminate with high brightness and long persistent luminescence were prepared at the first time by the combustion method at 600℃. The decay time of the persistence indicated that the persistent luminescence phosphor of SrAl2O4:Eu2+,Dy3+,Ho3+ have better phosphorescence than the tradition phosphor of SrAl2O4:Eu2+,Dy3+.
Density Functional Theory Study of Electronic Structure and Interaction of Pd、La Modified γ-Al2O3(110D) Surface
Density Functional Theory Study of Electronic Structure and Interaction of Pd、La Modified γ-Al2O3(110D) Surface
The modified methods containing deposited or doped transition metals、rare earth were adopted to enchanting the catalytic activity ofγ-Al2O3. For understanding the surface electronic structure、revealing the mechanism of surface reactivity and synthesizing new burning catalyst, it is necessary to study the behavior of Pd、La modifiedγ-Al2O3(110D)surface. With decade years ascribe to the increasing of computation level and methods, the Density Functional Theory Cube neodymium magnet has gone through a rapid development, and has been used to investigate the metal-oxide system. In this paper, a systematic investigation of Pd atoms、dimers and La modifiedγ-Al2O3 surface has been carried out by means of periodic DFT calculation. The calculated content as follows:(1) At first we optimized theγ-Al2O3(100)、(110D)surface and considered the surface relaxation. The result showed theγ-Al2O3(110D)surface is more stable than the(100)surface. We have obtained the most favorite adsorption site, electron transfer through calculated the CHx(x=0～4)species on theγ-Al2O3(110D)surface.(2) For Pd atoms, dimers deposited onγ-Al2O3(110D)surface, the calculated result showed Pd prefer to bind on bridge site of two O(2f)ofγ-Al2O3(110D)surface; dimers prefer to http://www.chinamagnets.biz/ bonding with Al, O of surface. The Pd is active surface site for the deposited system.(3) For La adsorption onγ-Al2O3(110D)surface, we calculated the structure, energy, density of states and work function change and compared with system of La dopedγ-Al2O3(110D)surface. The results showed that after doping La,γ-Al2O3(110D)surface electronic easier to leave the surface, formation of electron hole, raiseγ-Al2O3 (110D)surface activity.
The modified methods containing deposited or doped transition metals、rare earth were adopted to enchanting the catalytic activity ofγ-Al2O3. For understanding the surface electronic structure、revealing the mechanism of surface reactivity and synthesizing new burning catalyst, it is necessary to study the behavior of Pd、La modifiedγ-Al2O3(110D)surface. With decade years ascribe to the increasing of computation level and methods, the Density Functional Theory Cube neodymium magnet has gone through a rapid development, and has been used to investigate the metal-oxide system. In this paper, a systematic investigation of Pd atoms、dimers and La modifiedγ-Al2O3 surface has been carried out by means of periodic DFT calculation. The calculated content as follows:(1) At first we optimized theγ-Al2O3(100)、(110D)surface and considered the surface relaxation. The result showed theγ-Al2O3(110D)surface is more stable than the(100)surface. We have obtained the most favorite adsorption site, electron transfer through calculated the CHx(x=0～4)species on theγ-Al2O3(110D)surface.(2) For Pd atoms, dimers deposited onγ-Al2O3(110D)surface, the calculated result showed Pd prefer to bind on bridge site of two O(2f)ofγ-Al2O3(110D)surface; dimers prefer to http://www.chinamagnets.biz/ bonding with Al, O of surface. The Pd is active surface site for the deposited system.(3) For La adsorption onγ-Al2O3(110D)surface, we calculated the structure, energy, density of states and work function change and compared with system of La dopedγ-Al2O3(110D)surface. The results showed that after doping La,γ-Al2O3(110D)surface electronic easier to leave the surface, formation of electron hole, raiseγ-Al2O3 (110D)surface activity.
2012年7月24日星期二
Formation and Mechanisim of Up-Converting Matrix Phosphors
Formation and Mechanisim of Up-Converting Matrix Phosphors
Up-converting fluorescent nanocrystalline is a sort of material emits short wavelength light after excitated with long wavelength light. Most of them are attributed to inorganic material, for example, ytterbium and erbium co-doped yttrium fluoride, sodium yttrium fluoride, lanthanum fluoride, etc. Up-converting fluorescent material can emit different color visible fluorescence after excitated with 980 nm infrared light.Up-converting nanoparticles with few background and high detective sensitivity are a promising bio-molecule label. Until now, ytterbium and Alnico magnets erbium co-doped sodium yttrium fluoride (NaYF4: Yb, Er) is among the most efficient up-conversion phosphors. Its potential application in biological and medical fields has interested many scientists. As bio-molecule fluorescent labeling material, nanoparticles with small diameter, uniform distribution and strong luminescent intensity are necessary.
Considering the application in practice, the size of the fluorescent nanoparticles was dominated by the original diameter of the matrix material. Therefore, if the smaller and uniform matrix nanoparticles could be synthesized, that should be significant for research of the material applied in bio-molecule label.Based on the similarity of rare earth elements, this work focus on studying the formation mechanism and reaction affecting factors of NaYF4 nanoparticles without doping in aqueous phase, The obtained results are described as follows:(1) By investigating the effect of reactant time evolution and seeding effect for the formation of NaYF4 particles, the result that NaYF4 nanoparticles synthesized in aqueous grew in aggregation model, but not the typical LaMer model was concluded.(2) http://www.999magnet.com/ Reactant factors of reactant materials pH and chelators of EDTA for affecting the synthesis of NaYF4 nanoparticles were studied. Y(ClO4)3 was helpful for getting smaller NaYF4 particles than YCl3 was found. Particles remained almost unchanged, when pH of the aqueous phase was in the range of 4-10. The molar ratio of chelators to yttrium and the amount of fluorin ion should be in a proper range so that small nanosized particles can be obtained. In this paper, under the condition of [EDTA] : [Y3+] = 1 and [NaF] = 0.5 mol/L, NaYF4 of 30 nm was synthesized by Y(ClO4)3.(3) NaYF4 nanocrystalline was prepared in the presence of chelators such as EDTA, Na-NTA, Na-Citrate. Nanoparticles of 12 nm were obtained by 0.12 mol /L Na-Citrate. Thereout, comparison of amino carboxyl chelating and hydroxy carboxylic chelating affecting the synthesis of NaYF4 was studied.(4) Up-converting nanocrystal material of ytterbium and erbium co-doped sodium yttrium fluoride (NaYF4: Yb, Er) with 10 nm was achieved in the presence of high concentrated Na-NTA.
Up-converting fluorescent nanocrystalline is a sort of material emits short wavelength light after excitated with long wavelength light. Most of them are attributed to inorganic material, for example, ytterbium and erbium co-doped yttrium fluoride, sodium yttrium fluoride, lanthanum fluoride, etc. Up-converting fluorescent material can emit different color visible fluorescence after excitated with 980 nm infrared light.Up-converting nanoparticles with few background and high detective sensitivity are a promising bio-molecule label. Until now, ytterbium and Alnico magnets erbium co-doped sodium yttrium fluoride (NaYF4: Yb, Er) is among the most efficient up-conversion phosphors. Its potential application in biological and medical fields has interested many scientists. As bio-molecule fluorescent labeling material, nanoparticles with small diameter, uniform distribution and strong luminescent intensity are necessary.
Considering the application in practice, the size of the fluorescent nanoparticles was dominated by the original diameter of the matrix material. Therefore, if the smaller and uniform matrix nanoparticles could be synthesized, that should be significant for research of the material applied in bio-molecule label.Based on the similarity of rare earth elements, this work focus on studying the formation mechanism and reaction affecting factors of NaYF4 nanoparticles without doping in aqueous phase, The obtained results are described as follows:(1) By investigating the effect of reactant time evolution and seeding effect for the formation of NaYF4 particles, the result that NaYF4 nanoparticles synthesized in aqueous grew in aggregation model, but not the typical LaMer model was concluded.(2) http://www.999magnet.com/ Reactant factors of reactant materials pH and chelators of EDTA for affecting the synthesis of NaYF4 nanoparticles were studied. Y(ClO4)3 was helpful for getting smaller NaYF4 particles than YCl3 was found. Particles remained almost unchanged, when pH of the aqueous phase was in the range of 4-10. The molar ratio of chelators to yttrium and the amount of fluorin ion should be in a proper range so that small nanosized particles can be obtained. In this paper, under the condition of [EDTA] : [Y3+] = 1 and [NaF] = 0.5 mol/L, NaYF4 of 30 nm was synthesized by Y(ClO4)3.(3) NaYF4 nanocrystalline was prepared in the presence of chelators such as EDTA, Na-NTA, Na-Citrate. Nanoparticles of 12 nm were obtained by 0.12 mol /L Na-Citrate. Thereout, comparison of amino carboxyl chelating and hydroxy carboxylic chelating affecting the synthesis of NaYF4 was studied.(4) Up-converting nanocrystal material of ytterbium and erbium co-doped sodium yttrium fluoride (NaYF4: Yb, Er) with 10 nm was achieved in the presence of high concentrated Na-NTA.
2012年7月16日星期一
The Microstructure and Spectra of a Phosphor with Wider Excitation Bands for White LEDs
The Microstructure and Spectra of a Phosphor with Wider Excitation Bands for White LEDs
White LEDs (WLEDs) has become one of the key hi-technology world Wide due to its attractive advantages of energy consumption saving, environmental and lifetime long-lasting aspects. The YAG:Ce3+ phosphor puimped with chip blue light needs innovation to improve the properties. Of these, the silicate host phosphors with UV, nUV or blue-UV lights in wider excitation wavelength range for white-emitting is one of the innovative and competitive approaches.Neodymium Magnets With the aim to the problems mentioned above, we investigated a new rare earth doped silicate base phosphor. The relationship between preparation, microstructure and luminescent properties presented experimentally and theoretically in detail. The important results we obtained are described as follows:A. A spray-pyrolysis procedure was employed to prepare phase-pure rare-earth doped silicate base phosphors. The measured wavelengths of these phosphors range from 350nm to 470nm. The typical emission wavelength lies at 567nm upon exited by 470nm light.B. The relationships between microstructure and luminescent properties of these silicate base phosphors are primarily obtained. The lower energy edge location of Eu2+ ion is found to correspond to a six-coordinated number by using Uiteret formula. Furthermore, the XRD ptterns, morphologies and spectra of SrxCa2-xSiO4、SrxMg2-xSiO4 and SrxBa2-xSiO4 phosphors were also characterized.C. A series of process parameters involved in spray-pyrolysis procedure, such as composition, sintering temperature were experimentally investigated.D. The as-received phosphor particles is self-assembled, loose, submicron sized,ball-mill free powders, resulting in http://www.999magnet.com/ improving the luminescent properties.E.We evaluate the stability of these phosphors, that is, chemical stability and thermal stability respectively.F. This process offers a resource saving, environmental-friendly and scalable competition capability to prepare the phosphors.
White LEDs (WLEDs) has become one of the key hi-technology world Wide due to its attractive advantages of energy consumption saving, environmental and lifetime long-lasting aspects. The YAG:Ce3+ phosphor puimped with chip blue light needs innovation to improve the properties. Of these, the silicate host phosphors with UV, nUV or blue-UV lights in wider excitation wavelength range for white-emitting is one of the innovative and competitive approaches.Neodymium Magnets With the aim to the problems mentioned above, we investigated a new rare earth doped silicate base phosphor. The relationship between preparation, microstructure and luminescent properties presented experimentally and theoretically in detail. The important results we obtained are described as follows:A. A spray-pyrolysis procedure was employed to prepare phase-pure rare-earth doped silicate base phosphors. The measured wavelengths of these phosphors range from 350nm to 470nm. The typical emission wavelength lies at 567nm upon exited by 470nm light.B. The relationships between microstructure and luminescent properties of these silicate base phosphors are primarily obtained. The lower energy edge location of Eu2+ ion is found to correspond to a six-coordinated number by using Uiteret formula. Furthermore, the XRD ptterns, morphologies and spectra of SrxCa2-xSiO4、SrxMg2-xSiO4 and SrxBa2-xSiO4 phosphors were also characterized.C. A series of process parameters involved in spray-pyrolysis procedure, such as composition, sintering temperature were experimentally investigated.D. The as-received phosphor particles is self-assembled, loose, submicron sized,ball-mill free powders, resulting in http://www.999magnet.com/ improving the luminescent properties.E.We evaluate the stability of these phosphors, that is, chemical stability and thermal stability respectively.F. This process offers a resource saving, environmental-friendly and scalable competition capability to prepare the phosphors.
2012年7月15日星期日
Investigation on Microstructure and Properties of Low Silver-Containing Cadmium-Free Intermediate Temperature Brazing Filler Metals
Investigation on Microstructure and Properties of Low Silver-Containing Cadmium-Free Intermediate Temperature Brazing Filler Metals
The cadmium-containing silver-based brazing filler metal with low melting temperature and good technologic property is applied extensively to the bonding of mild steel, stainless steel, dissimilar metal, copper and copper alloy in the industry field. The obtained bonding joints have good properties. But cadmium element is toxic, and harmful to human health if contacting it in a long time. In this paper, low silver-containing cadmium-free intermediate Block neodymium magnet temperature brazing filler metals were investigated. Effect of alloy element on melting property, microstructure, wettability of brazing filler metals and joint mechanical properties was researched by changing the content of alloy element on the AgCuZn alloy system. And joint microstructure was observed and analyzed simultaneously.Effect of alloy element on the melting point and melting temperature range was studied by DTA analysis.
The result shows that melting temperature descends with the increase of Sn or P content, but ascends with the increasing of Ni content. The addition of Ni and P in the brazing filler metals can reduce the melting temperature range, and improve the alloy fluidity. But the excessive addition of Sn will increase the temperature range, and lead to a bad influence on the alloy fluidity.The experimental brazing filler metals and joint interface were analyzed by SEM, EDAX and XRD. The result shows that AgCuZn experimental brazing filler metals mainly consist of Cu-rich phase, CuZn compound, Cu5.6Sn compound, Cu40.5Sn11 compound and Ag-rich phase. Phosphorus exists as Cu3P compound in the brazing filler metals. Addition of La can make microstructure homogeneous, http://www.chinamagnets.biz/ and restrain the growth of IMC. Dendrite that forms in the alloy microstructure will be broken into pieces after the addition of Ni. Interfacial microstructure of copper-joint is good, and brazing seam consists of diffusion layer and remainder of brazing filler metal. Iron-base solid solution layer and intergranular penetrating structure exist in the stainless steel brazing seam.The result of wettability experiment for AgCuZn brazing filler metals shows that wettability for copper is better than wettability for stainless steel. Wettability of the experimental brazing filler metals is similar to BAg30CuZnSn, but not better than BAg40CuZnSn. Alloy element Sn and P can improve wettability. When the La content is more than 0.5%, the wettability of experimental brazing filler metals will descend.Joint mechanical properties were analyzed. The result shows that the shearing strength of stainless steel joint of the experimental brazing filler metals is about 90MPa, the shearing strength of copper joint can reach to 110MPa.
The cadmium-containing silver-based brazing filler metal with low melting temperature and good technologic property is applied extensively to the bonding of mild steel, stainless steel, dissimilar metal, copper and copper alloy in the industry field. The obtained bonding joints have good properties. But cadmium element is toxic, and harmful to human health if contacting it in a long time. In this paper, low silver-containing cadmium-free intermediate Block neodymium magnet temperature brazing filler metals were investigated. Effect of alloy element on melting property, microstructure, wettability of brazing filler metals and joint mechanical properties was researched by changing the content of alloy element on the AgCuZn alloy system. And joint microstructure was observed and analyzed simultaneously.Effect of alloy element on the melting point and melting temperature range was studied by DTA analysis.
The result shows that melting temperature descends with the increase of Sn or P content, but ascends with the increasing of Ni content. The addition of Ni and P in the brazing filler metals can reduce the melting temperature range, and improve the alloy fluidity. But the excessive addition of Sn will increase the temperature range, and lead to a bad influence on the alloy fluidity.The experimental brazing filler metals and joint interface were analyzed by SEM, EDAX and XRD. The result shows that AgCuZn experimental brazing filler metals mainly consist of Cu-rich phase, CuZn compound, Cu5.6Sn compound, Cu40.5Sn11 compound and Ag-rich phase. Phosphorus exists as Cu3P compound in the brazing filler metals. Addition of La can make microstructure homogeneous, http://www.chinamagnets.biz/ and restrain the growth of IMC. Dendrite that forms in the alloy microstructure will be broken into pieces after the addition of Ni. Interfacial microstructure of copper-joint is good, and brazing seam consists of diffusion layer and remainder of brazing filler metal. Iron-base solid solution layer and intergranular penetrating structure exist in the stainless steel brazing seam.The result of wettability experiment for AgCuZn brazing filler metals shows that wettability for copper is better than wettability for stainless steel. Wettability of the experimental brazing filler metals is similar to BAg30CuZnSn, but not better than BAg40CuZnSn. Alloy element Sn and P can improve wettability. When the La content is more than 0.5%, the wettability of experimental brazing filler metals will descend.Joint mechanical properties were analyzed. The result shows that the shearing strength of stainless steel joint of the experimental brazing filler metals is about 90MPa, the shearing strength of copper joint can reach to 110MPa.
Fabrication and Research on Properties Materials of the Strontium Barium Niobate Ceramic
Fabrication and Research on Properties Materials of the Strontium Barium Niobate Ceramic
According to the latest development and shortcoming of the ceramics of niobate,the e?ects of the glass additives, oxide replacement and fabrication methods on struc-ture, sintering, phase compositions, dielectric properties were investigated by usingthe Di?erential thermal analysis (DTA), X-ray di?raction (XRD), Scanning electronmicroscope (SEM) and AC Ball Neodymium Magnets impedance. The results showed as the following:The in?uence of titanium dioxide and sintering on the phase compositions anddielectric properties were investigated. The peak of SBT was not observed in the graphof XRD when the y value was no more than 0.1 and the phase of SBT was melted in thephase of SBN. The peaks of SBT and SBN were observed at the same time when they value was no less than 0.2 and they are coexisting. The density of SBTN ceramicsincreased with the increasing of temperature when the sintering temperature below1300℃. When the temperature was higher than 1300℃, the density of samples thatthe y value equals to 0 and 0.1 decreased with the rising of temperature and the samplesthat the y value equals to 0.2 and 0.3 were increased. The max dielectric constant ofceramics was 11798 when the y value equals to 0.1. The in?uence of La3+ and Ce4+ onthe ceramics of SBTN was investigated. The ion of Nb5+ was replaced by La3+ resultsin the hollow of structure and the crystal distance’s minishing. The doping of Ce4+ wascomplex and made no in?uence to crystal parameter. The relative densities of samplesdoped by La3+ and Ce4+ decreased, the dielectric constant and loss decreased and thestabilization of dielectric constant increased.The e?ects of alkali on the phase transitions, dielectric properties of strontiumbarium niobate were discussed. The Sr2+ and Ba2+ in position A of tungsten bronze canbe replaced by Ca2+ and the position C can be filled by Mg2+. The size of the particle ofceramics with Ca and Mg doped sintered at 1300℃grew bigger. The Curie temperatureof the ceramics doped with Ca came out at 150℃and 330℃which corresponding to SBNand (Sr、Ba、Ca)Nb2O6 respectively.
The Curie peak disappeared when the amountof Ca doped increased step by step. The Curie temperature of the ceramics dopedwith Mg came out at 150℃and 310℃.The two peaks combined and moved to lowtemperature with the increasing of Mg doped.The co-fired ceramics of low-melting material and strontium barium niobate wereput forward for the first time. As the result of the crystal of strontium barium nio-bate can be enwrapped by the low-melting material what can form the structure of“shell-core”in the sintering, the properties of strontium barium niobate http://www.chinamagnets.biz/ ceramics canbe improved. The SBN ceramics of CBS glass doped were formed at 1100℃and noother phase was observed, which can reduce the sintering temperature. The Curie temperature and the dielectric constant of SBN ceramics decreased and then increasedwith the increasing of CBS glass.The phase of CaNbO3 came out when the amount of CBS doped was more than 8mol%, which made serious e?ects on dielectric properties. Strontium barium niobatepowder, Sr0.5Ba0.5Nb2O6 (SBN50), has been fabricated for the first time by high-energyball milling on a mixture of Nb2O5, BaCO3 and SrCO3. SBN50 ceramics have beenobtained by sintering the green compacts derived from milled 30 h powder mixturewithout calcining at 1250, 1280, 1300 and 1350℃for 1.5-12 h. The phase and mi-crostructure evolution of the samples were characterized by X-ray di?raction and scan-ning electron microscopy. The properties of SBN50 ceramics were also measured. Theresults show that the Ball Neodymium Magnets single phase SBN50 formed at 1100℃and the dielectric constantfirstly increases and then decreases with the rising of sintering temperature and soakingtime. The grain size of the sintered samples in di?erent conditions changed regularly.Highest dielectric constant (εmax=1147) at 1 kHz frequency has been obtained forthe pellet sintered at 1300℃for 3 h.The Curie Temperature (Tc) is 130℃.
According to the latest development and shortcoming of the ceramics of niobate,the e?ects of the glass additives, oxide replacement and fabrication methods on struc-ture, sintering, phase compositions, dielectric properties were investigated by usingthe Di?erential thermal analysis (DTA), X-ray di?raction (XRD), Scanning electronmicroscope (SEM) and AC Ball Neodymium Magnets impedance. The results showed as the following:The in?uence of titanium dioxide and sintering on the phase compositions anddielectric properties were investigated. The peak of SBT was not observed in the graphof XRD when the y value was no more than 0.1 and the phase of SBT was melted in thephase of SBN. The peaks of SBT and SBN were observed at the same time when they value was no less than 0.2 and they are coexisting. The density of SBTN ceramicsincreased with the increasing of temperature when the sintering temperature below1300℃. When the temperature was higher than 1300℃, the density of samples thatthe y value equals to 0 and 0.1 decreased with the rising of temperature and the samplesthat the y value equals to 0.2 and 0.3 were increased. The max dielectric constant ofceramics was 11798 when the y value equals to 0.1. The in?uence of La3+ and Ce4+ onthe ceramics of SBTN was investigated. The ion of Nb5+ was replaced by La3+ resultsin the hollow of structure and the crystal distance’s minishing. The doping of Ce4+ wascomplex and made no in?uence to crystal parameter. The relative densities of samplesdoped by La3+ and Ce4+ decreased, the dielectric constant and loss decreased and thestabilization of dielectric constant increased.The e?ects of alkali on the phase transitions, dielectric properties of strontiumbarium niobate were discussed. The Sr2+ and Ba2+ in position A of tungsten bronze canbe replaced by Ca2+ and the position C can be filled by Mg2+. The size of the particle ofceramics with Ca and Mg doped sintered at 1300℃grew bigger. The Curie temperatureof the ceramics doped with Ca came out at 150℃and 330℃which corresponding to SBNand (Sr、Ba、Ca)Nb2O6 respectively.
The Curie peak disappeared when the amountof Ca doped increased step by step. The Curie temperature of the ceramics dopedwith Mg came out at 150℃and 310℃.The two peaks combined and moved to lowtemperature with the increasing of Mg doped.The co-fired ceramics of low-melting material and strontium barium niobate wereput forward for the first time. As the result of the crystal of strontium barium nio-bate can be enwrapped by the low-melting material what can form the structure of“shell-core”in the sintering, the properties of strontium barium niobate http://www.chinamagnets.biz/ ceramics canbe improved. The SBN ceramics of CBS glass doped were formed at 1100℃and noother phase was observed, which can reduce the sintering temperature. The Curie temperature and the dielectric constant of SBN ceramics decreased and then increasedwith the increasing of CBS glass.The phase of CaNbO3 came out when the amount of CBS doped was more than 8mol%, which made serious e?ects on dielectric properties. Strontium barium niobatepowder, Sr0.5Ba0.5Nb2O6 (SBN50), has been fabricated for the first time by high-energyball milling on a mixture of Nb2O5, BaCO3 and SrCO3. SBN50 ceramics have beenobtained by sintering the green compacts derived from milled 30 h powder mixturewithout calcining at 1250, 1280, 1300 and 1350℃for 1.5-12 h. The phase and mi-crostructure evolution of the samples were characterized by X-ray di?raction and scan-ning electron microscopy. The properties of SBN50 ceramics were also measured. Theresults show that the Ball Neodymium Magnets single phase SBN50 formed at 1100℃and the dielectric constantfirstly increases and then decreases with the rising of sintering temperature and soakingtime. The grain size of the sintered samples in di?erent conditions changed regularly.Highest dielectric constant (εmax=1147) at 1 kHz frequency has been obtained forthe pellet sintered at 1300℃for 3 h.The Curie Temperature (Tc) is 130℃.
Preparation and Magnetic Properties of Substituted Spinel Zn/Co Ferrite
Preparation and Magnetic Properties of Substituted Spinel Zn/Co Ferrite
Ferrites are important magnetic functional materials which are used in many fields. The synthesis of the powder has always been the subject of extensive studies. In this paper, the spinel ferrites were synthesized by oxalate co-precipitation method. The synthesizing conditions, structure and magnetic properties were groped. The structure was characterized by neodymium magnets XRD, TG-DSC, SEM and FT-IR.The magnetic properties were tested by VSM.The main contents of this thesis are as follows:A series of nanosize spinel ferrites of ZnFe2O4,CoFe2O4 and ZnxCo1-xFe2O4 were synthesized by oxalate co-precipitation method. The results showed the specific saturation magnetization (σs) of ZnFe2O4 has a maximum at the calcining temperature is 800℃,σs=32.45A·m2·kg-1.The specific saturation magnetization (σs) of CoFe2O4 has a maximum at the calcining temperature is 900℃,σs=35.95A·m2·kg-1.The specific saturation magnetization (σs) of ZnxCo1-xFe2O4 has a maximum at x=0.3,σs=63.48A·m2·kg-1.The doping element on Zn0.3Co0.7Fe2O4 ferrite was synthesized by oxalate co-precipitation method. The influence of doping element on Zn0.3Co0.7Fe2O4 ferrite structures http://www.chinamagnets.biz/ and magnetic properties was discussed. The result indicated that specific saturation magnetization of Zn0.3Co0.7LaxFe2-xO4 is decreasing when x is increasing. The specific saturation magnetization of Zn0.3Co0.7YxFe2-xO4 has a maximum at x=0.04,σs=66.89 A·m2a kg-1.
Ferrites are important magnetic functional materials which are used in many fields. The synthesis of the powder has always been the subject of extensive studies. In this paper, the spinel ferrites were synthesized by oxalate co-precipitation method. The synthesizing conditions, structure and magnetic properties were groped. The structure was characterized by neodymium magnets XRD, TG-DSC, SEM and FT-IR.The magnetic properties were tested by VSM.The main contents of this thesis are as follows:A series of nanosize spinel ferrites of ZnFe2O4,CoFe2O4 and ZnxCo1-xFe2O4 were synthesized by oxalate co-precipitation method. The results showed the specific saturation magnetization (σs) of ZnFe2O4 has a maximum at the calcining temperature is 800℃,σs=32.45A·m2·kg-1.The specific saturation magnetization (σs) of CoFe2O4 has a maximum at the calcining temperature is 900℃,σs=35.95A·m2·kg-1.The specific saturation magnetization (σs) of ZnxCo1-xFe2O4 has a maximum at x=0.3,σs=63.48A·m2·kg-1.The doping element on Zn0.3Co0.7Fe2O4 ferrite was synthesized by oxalate co-precipitation method. The influence of doping element on Zn0.3Co0.7Fe2O4 ferrite structures http://www.chinamagnets.biz/ and magnetic properties was discussed. The result indicated that specific saturation magnetization of Zn0.3Co0.7LaxFe2-xO4 is decreasing when x is increasing. The specific saturation magnetization of Zn0.3Co0.7YxFe2-xO4 has a maximum at x=0.04,σs=66.89 A·m2a kg-1.
2012年7月10日星期二
Study of Density States of La0.67Ca0.33MnO3 and Magnetic Reversal Phenomenon in Nd1-xZrxMnO3
Study of Density States of La0.67Ca0.33MnO3 and Magnetic Reversal Phenomenon in Nd1-xZrxMnO3
Manganites with porverskite structures have attracted researchers’attention not only because their wide prospect of application in electron spin devices, but also they provide platforms for basic research. In this thesis, we prepare hole-doped and electrons-doped manganites by pechini process, and investigate their physical properties systematically.LCMO/AlO/Al tunnel junction was fabricated with magnetic sputtering technology on the LCMO bulk with good connectivity between grain boundaries which was sufficiently polished. Temperature dependence of density of states (DOS) was investigated via the dI/dV-V curve. It was found that far below the courier temperature the DOS had stronger dependence on energy than that for temperature near and above courier temperature.Neodymium Magnets We fitted the tunneling conductance near the Fermi-level with the equation , the results shows that the system reveals good metallic property and the effect of electron-electron interaction can be quite prominent.Nd1-xZrxMnO3 and Pr1-xZrxMnO3 compounds was successfully synthesized by sol-gel process, the x-ray photoemission spectroscopy investigation shows that, the Mn cations of the sample are in the divalent and trivalent states after Zr was introduced means that the systems were electron doped. In addition, for Nd1-xZrxMnO3, the M-T curve during both ZFC and FC process shows negative magnetization, which was also called magnetic reversal .In comparison, Pr, being similar with Nd, which belongs to the light thulium material, has no sign of magnetic reversal in higher temperature region. Combining the previous study, we proposed that the appearance of magnetic reversal during the higher temperature http://www.999magnet.com/ region was result from the competition between two antiferromagnetic coupled lattices Mn2+/Mn3+ and Mn3+/Mn3+, while in low temperature region It may related with the ordering of Nd3+ ions .and the peak of the specific heat in low temperature provides an effective evidence for the ordering of Nd3+ ions in low temperature.
Manganites with porverskite structures have attracted researchers’attention not only because their wide prospect of application in electron spin devices, but also they provide platforms for basic research. In this thesis, we prepare hole-doped and electrons-doped manganites by pechini process, and investigate their physical properties systematically.LCMO/AlO/Al tunnel junction was fabricated with magnetic sputtering technology on the LCMO bulk with good connectivity between grain boundaries which was sufficiently polished. Temperature dependence of density of states (DOS) was investigated via the dI/dV-V curve. It was found that far below the courier temperature the DOS had stronger dependence on energy than that for temperature near and above courier temperature.Neodymium Magnets We fitted the tunneling conductance near the Fermi-level with the equation , the results shows that the system reveals good metallic property and the effect of electron-electron interaction can be quite prominent.Nd1-xZrxMnO3 and Pr1-xZrxMnO3 compounds was successfully synthesized by sol-gel process, the x-ray photoemission spectroscopy investigation shows that, the Mn cations of the sample are in the divalent and trivalent states after Zr was introduced means that the systems were electron doped. In addition, for Nd1-xZrxMnO3, the M-T curve during both ZFC and FC process shows negative magnetization, which was also called magnetic reversal .In comparison, Pr, being similar with Nd, which belongs to the light thulium material, has no sign of magnetic reversal in higher temperature region. Combining the previous study, we proposed that the appearance of magnetic reversal during the higher temperature http://www.999magnet.com/ region was result from the competition between two antiferromagnetic coupled lattices Mn2+/Mn3+ and Mn3+/Mn3+, while in low temperature region It may related with the ordering of Nd3+ ions .and the peak of the specific heat in low temperature provides an effective evidence for the ordering of Nd3+ ions in low temperature.
Geochemical Characters and Petrogenesis of Kalatongke Basic Rock Body in Xinjiang
Geochemical Characters and Petrogenesis of Kalatongke Basic Rock Body in Xinjiang
Kalatongke Cu-Ni ore district lies in east of Saerbulake-Sasekebasitao synclinorium in Junggar fold system, which is the boundary of Altai Caledonian fold system and Junggar Hercynian fold system. This area develops a series of second-order folds and subsidiary fractures, and composed by eleven rock bodies(Y1-Y9,Y10、Y11) and G21、G22 gravity abnormal district and AM16 aeromagnetic anomaly district. Although predecessors make a lot of research about the Kalatongke rock body, there are still some controversial issues. This paper according to systematically research the petrography, crystal chemistry, rare earth elements, trace elements and Sr, Nd, Pb and Re-Os isotopic geochemistry of Kalatongke rock body, scientifically demonstrates its magmatic process,Ball Neodymium Magnets magma nature and mantle source district features. Based on these researches we get some initial understanding as follows:1. The main rock types are diabase-gabbro, gabbro, biotite hornblende olivine norite, gabbro-norite, norite, diorite, the quantity of ultrabasic rock is few, and the main ore-bearing rock is norite, the main rock-forming minerals are olivine, pyroxene, plagioclase, hornblende and biotite. Its formation age is 287±5Ma, belongs to the early Permian.2. The REE partitioning pattern is LREE enrichment, the Eu anomaly is not obvious, and enriches LILE, correspondingly depleted HFSE. The Nd、Sr、Pb isotopes show that it comes from the depleted mantle. The magma source is asthenosphere, and the source matter is composed by asthenosphere matter and metasomatic lithosphere mantle matter.
The rock body is formed in post-collision extended environment.3. Kalatongke Y1-Y11 and G21 rock body is the identical rock body troop, it is the result of the same primary magma evolved, AM16 doesn’t belong to the identical rock body troop; The rock body can be divided into three group: the first group is the Y1、Y2 rock body, is mainly composed by low evolution degree magma, but they also contain a few upper evolution degree magma; the second group is the Y3、Y5 rock body, is mainly composed by moderate evolved magma, but they also contain a few high evolved degree magma; the third group is the Y7、Y8、Y9、G21 rock body, is mainly composed by evolved magma; The magma channel-way of the rock body should be existed between the Y1 and Y2 rock body. 4. A majority of magma which forms the rock body is not the primary magma, it mainly http://www.chinamagnets.biz/
composed by different evolution degree magma. The parental magma is basaltic magma, and its content of MgO is a little high, the content of MgO is 9.42%. When the magma is in the course of rising it should be hybridized a little by the crust substance, the magma rises from the source to emplacement at least experiences twice magma chamber fractional crystallization process. When the magma is in the course of rising because of the density, it forms deep magma chamber in the deep, and there it takes place the fractional crystallization, the main mineral is olivine and there is a little orthopyroxene. The evolved magma rises into the exalted magma chamber and takes place the fractional crystallization of clinopyroxene and on-spot differentiation, and then forms current Kalatongke basic rock body.
Kalatongke Cu-Ni ore district lies in east of Saerbulake-Sasekebasitao synclinorium in Junggar fold system, which is the boundary of Altai Caledonian fold system and Junggar Hercynian fold system. This area develops a series of second-order folds and subsidiary fractures, and composed by eleven rock bodies(Y1-Y9,Y10、Y11) and G21、G22 gravity abnormal district and AM16 aeromagnetic anomaly district. Although predecessors make a lot of research about the Kalatongke rock body, there are still some controversial issues. This paper according to systematically research the petrography, crystal chemistry, rare earth elements, trace elements and Sr, Nd, Pb and Re-Os isotopic geochemistry of Kalatongke rock body, scientifically demonstrates its magmatic process,Ball Neodymium Magnets magma nature and mantle source district features. Based on these researches we get some initial understanding as follows:1. The main rock types are diabase-gabbro, gabbro, biotite hornblende olivine norite, gabbro-norite, norite, diorite, the quantity of ultrabasic rock is few, and the main ore-bearing rock is norite, the main rock-forming minerals are olivine, pyroxene, plagioclase, hornblende and biotite. Its formation age is 287±5Ma, belongs to the early Permian.2. The REE partitioning pattern is LREE enrichment, the Eu anomaly is not obvious, and enriches LILE, correspondingly depleted HFSE. The Nd、Sr、Pb isotopes show that it comes from the depleted mantle. The magma source is asthenosphere, and the source matter is composed by asthenosphere matter and metasomatic lithosphere mantle matter.
The rock body is formed in post-collision extended environment.3. Kalatongke Y1-Y11 and G21 rock body is the identical rock body troop, it is the result of the same primary magma evolved, AM16 doesn’t belong to the identical rock body troop; The rock body can be divided into three group: the first group is the Y1、Y2 rock body, is mainly composed by low evolution degree magma, but they also contain a few upper evolution degree magma; the second group is the Y3、Y5 rock body, is mainly composed by moderate evolved magma, but they also contain a few high evolved degree magma; the third group is the Y7、Y8、Y9、G21 rock body, is mainly composed by evolved magma; The magma channel-way of the rock body should be existed between the Y1 and Y2 rock body. 4. A majority of magma which forms the rock body is not the primary magma, it mainly http://www.chinamagnets.biz/
composed by different evolution degree magma. The parental magma is basaltic magma, and its content of MgO is a little high, the content of MgO is 9.42%. When the magma is in the course of rising it should be hybridized a little by the crust substance, the magma rises from the source to emplacement at least experiences twice magma chamber fractional crystallization process. When the magma is in the course of rising because of the density, it forms deep magma chamber in the deep, and there it takes place the fractional crystallization, the main mineral is olivine and there is a little orthopyroxene. The evolved magma rises into the exalted magma chamber and takes place the fractional crystallization of clinopyroxene and on-spot differentiation, and then forms current Kalatongke basic rock body.
2012年7月6日星期五
Study on Magnetic Properties of Fe3B/Nd2Fe14B Type Nanocrystalline Composite Permanent Magnets and Primary Discussion of Bonded Magnets
Study on Magnetic Properties of Fe3B/Nd2Fe14B Type Nanocrystalline Composite Permanent Magnets and Primary Discussion of Bonded Magnets
Nanocrystalline composite permanent magnetic material is a new type of permanent magnetic material developed in recent years, that is consisted of soft and hard magnetic phases in the nanoscale, shows single ferromagnetic phase’s magnetization and antimagnetization characteristics by exchange couple effect between soft and hard magnetic phases, Block neodymium magnet and possesses remanence enhancement effect. Its maximum energy product (BH) max can get 1 MJ/m3 theoretically, which exceeds any single-phase permanent magnetic materials; And it maybe developed to be a further novel generation of bonded permanent magnetic material, owing to the low rare earth content, high chemical stability, low costs, high practical value and good applications in the future.But the exchange couple interaction between soft and hard magnetic phases is belong to short-range exchange interaction, if in order to obtain high magnetic properties, then do control two phases’ grain size and improve microstructure by ingredient optimizing, process improving to more improve magnetic properties.In the paper, though low Nd-content’s (containing 4.5at%) nanocomposite permanent magnetic material properties are lower than high Nd-content’s, however, due to high remanence, very low costs and application in many low request fields, the present research work is meaningful.First, discussing 4.5at% Nd-content’s nanocomposite permanent material Nd4.5Fe74.5+xB21-x (with x varying between 0 and 4 in increments of 1), while the basic component B is to some extent, permanent magnets’ properties is http://www.chinamagnets.biz/ optimum. Last result shows that 20at% B-content’s permanent magnet’s properties are optimum.Second, to investigate the change of Tb-content causing accordingly magnetic properties’ change, the sample Nd4.5-xTbxFe75.5B20 (with x varying between 0.25 and 1.25 in increments of 0.25)
Nanocrystalline composite permanent magnetic material is a new type of permanent magnetic material developed in recent years, that is consisted of soft and hard magnetic phases in the nanoscale, shows single ferromagnetic phase’s magnetization and antimagnetization characteristics by exchange couple effect between soft and hard magnetic phases, Block neodymium magnet and possesses remanence enhancement effect. Its maximum energy product (BH) max can get 1 MJ/m3 theoretically, which exceeds any single-phase permanent magnetic materials; And it maybe developed to be a further novel generation of bonded permanent magnetic material, owing to the low rare earth content, high chemical stability, low costs, high practical value and good applications in the future.But the exchange couple interaction between soft and hard magnetic phases is belong to short-range exchange interaction, if in order to obtain high magnetic properties, then do control two phases’ grain size and improve microstructure by ingredient optimizing, process improving to more improve magnetic properties.In the paper, though low Nd-content’s (containing 4.5at%) nanocomposite permanent magnetic material properties are lower than high Nd-content’s, however, due to high remanence, very low costs and application in many low request fields, the present research work is meaningful.First, discussing 4.5at% Nd-content’s nanocomposite permanent material Nd4.5Fe74.5+xB21-x (with x varying between 0 and 4 in increments of 1), while the basic component B is to some extent, permanent magnets’ properties is http://www.chinamagnets.biz/ optimum. Last result shows that 20at% B-content’s permanent magnet’s properties are optimum.Second, to investigate the change of Tb-content causing accordingly magnetic properties’ change, the sample Nd4.5-xTbxFe75.5B20 (with x varying between 0.25 and 1.25 in increments of 0.25)
包头稀土高新区人力资源开发的对策及途径
包头稀土高新区人力资源开发的对策及途径
Among four kinds of resources of person, finance, thing, information in organization system, people has more and more realized the importance of person resources. The principle that makes people being the center goes deep into the public gradually. In future, the unique and competitive advantage that Business enterprises hold out for a long time is the Ball Neodymium Magnets ability and speed of internal human resource development. Nowadays, the concept of the human resource is most important resources of business enterprise have been widely accepted by all enterprises in Hi-Teeh Development Zone. However, the human resource development of the majority business enterprise still stays around the lower level. On the basis of the study of the character, the challenge, the significance and the trend of human resources, the paper introduces the approaches and the countermcasures to enhance the internal human resource development of the enterprises in Hi-Teeh http://www.chinamagnets.biz/ Zone from the aspects of building up of the organization of the study type and designing the training project and so on.
Among four kinds of resources of person, finance, thing, information in organization system, people has more and more realized the importance of person resources. The principle that makes people being the center goes deep into the public gradually. In future, the unique and competitive advantage that Business enterprises hold out for a long time is the Ball Neodymium Magnets ability and speed of internal human resource development. Nowadays, the concept of the human resource is most important resources of business enterprise have been widely accepted by all enterprises in Hi-Teeh Development Zone. However, the human resource development of the majority business enterprise still stays around the lower level. On the basis of the study of the character, the challenge, the significance and the trend of human resources, the paper introduces the approaches and the countermcasures to enhance the internal human resource development of the enterprises in Hi-Teeh http://www.chinamagnets.biz/ Zone from the aspects of building up of the organization of the study type and designing the training project and so on.
稀土镨掺杂的CaTiO3，La2O3发光材料的制备与表征
稀土镨掺杂的CaTiO3，La2O3发光材料的制备与表征
In this paper, adopted CaTiO3 and La2O3 as the hosts, two kinds of Pr3+-doped phosphors were prepared used different starting materials and by different methods, and characterized by PL spectrum, UV-Vis spectrum, XRD, SEM, FT-IR spectrum, DTS-TG The PL property and mechanism of Pr3+ doped in the two hosts were discussed respectively. The influence to the PL intensity and morphology of experimental conditions and synthetical methods were also studied.According to PL and UV-Vis spectrum, the process of luminescence of CaTiO3:Pr3+ can be described as the host absorbed the UV light, and transferred the energy to Pr3+. It can be excitated to neodymium magnets 5d states when Pr3+ gained the energy, and came back to 1D2 spectrum level by nonradiative transition on the instant, then transferred from 1D2 to 3H4, and ultimately, the red light with the wavelength of 613nm was emitted. Pr3+ also can be excitated to 5d states after absorbed the UV light by itself in La2O3:Pr3+. But it came back to 3P0 spectrum level by nonradiative transition, then transferred from 3P0 to 3H4, and emitted green light with the wavelength of 510 nm.
The energy level of charge transfer state(CTS) of Pr3+ is lower enough that 3P0 can not exist stably but easy to transfer to 1D2 by CTS in CaTiO3:Pr3+, and only can emit red light. This is also the main reason to explain the difference of luminescence of Pr3+ in the two hosts.When studied the influence to PL intensity of experimental conditions in the process of synthesizing CaTiO3:Pr3+, we found the traditional solid state reaction is better than liquid state reaction(sol-gel method, precipitation method), and prefer TiO2 aerogel to common TiO2 as the starting material. Improving sintering temperature conduce to intensifying the visible emission, and when sintered at 1200℃, CaTiO3:Pr3+ appears the most intense emission. The quench concentration of Pr3+ in CaTiO3:Pr3+ http://www.chinamagnets.biz/ is only 0.1% due to the exist of cross relaxation.The PL intensity of CaTiO3:Pr3+ can be enhanced at 325 nm when Al3+ was doped. It is attribute to charge compensation by Al3+ co-dope and eliminating more charge defects which produced by Pr3+ substituting Ca2+. The optimal concentration of Al3+ doped is between 8% and 15%. In this concentration range, the PL intensity become most intense, but this result is consistent with theoretical value of charge compensation. This result is also proved the
In this paper, adopted CaTiO3 and La2O3 as the hosts, two kinds of Pr3+-doped phosphors were prepared used different starting materials and by different methods, and characterized by PL spectrum, UV-Vis spectrum, XRD, SEM, FT-IR spectrum, DTS-TG The PL property and mechanism of Pr3+ doped in the two hosts were discussed respectively. The influence to the PL intensity and morphology of experimental conditions and synthetical methods were also studied.According to PL and UV-Vis spectrum, the process of luminescence of CaTiO3:Pr3+ can be described as the host absorbed the UV light, and transferred the energy to Pr3+. It can be excitated to neodymium magnets 5d states when Pr3+ gained the energy, and came back to 1D2 spectrum level by nonradiative transition on the instant, then transferred from 1D2 to 3H4, and ultimately, the red light with the wavelength of 613nm was emitted. Pr3+ also can be excitated to 5d states after absorbed the UV light by itself in La2O3:Pr3+. But it came back to 3P0 spectrum level by nonradiative transition, then transferred from 3P0 to 3H4, and emitted green light with the wavelength of 510 nm.
The energy level of charge transfer state(CTS) of Pr3+ is lower enough that 3P0 can not exist stably but easy to transfer to 1D2 by CTS in CaTiO3:Pr3+, and only can emit red light. This is also the main reason to explain the difference of luminescence of Pr3+ in the two hosts.When studied the influence to PL intensity of experimental conditions in the process of synthesizing CaTiO3:Pr3+, we found the traditional solid state reaction is better than liquid state reaction(sol-gel method, precipitation method), and prefer TiO2 aerogel to common TiO2 as the starting material. Improving sintering temperature conduce to intensifying the visible emission, and when sintered at 1200℃, CaTiO3:Pr3+ appears the most intense emission. The quench concentration of Pr3+ in CaTiO3:Pr3+ http://www.chinamagnets.biz/ is only 0.1% due to the exist of cross relaxation.The PL intensity of CaTiO3:Pr3+ can be enhanced at 325 nm when Al3+ was doped. It is attribute to charge compensation by Al3+ co-dope and eliminating more charge defects which produced by Pr3+ substituting Ca2+. The optimal concentration of Al3+ doped is between 8% and 15%. In this concentration range, the PL intensity become most intense, but this result is consistent with theoretical value of charge compensation. This result is also proved the
2012年7月3日星期二
Preparation of Silica-shell and Rare Earth Co-luminescent Composite Nanoparticles and Their Analytical Application
Preparation of Silica-shell and Rare Earth Co-luminescent Composite Nanoparticles and Their Analytical Application
Though traditional fluorescence analytical methods have excellent luminescence properties including good selectivity and sensitivity, steady fluorescence and convenient preparation, they still have some insurmountable disfigurements, such as photo bleaching of majority fluorescence reagent, unsteadiness of fluorescence signal, the side effect of fluorescence reagent to body cells. So we prepared steady composite nanoparticles as the fluorescence probes for the determination of trace substance with the advantages of easy preparation and good dispersity.In this Block Neodymium magnets paper, we successfully prepared composite fluorescence nanoparticles and use them as fluorescence probes to determine proteins and pH. The details are summarized as follows:(1) Water-in-oil microemulsion is a widely used method of preparing nanomaterials of small size. With this reversed micelles method, we prepared nano-pH sensor based on fluorescent silica nanoparticles developed by encapsulating dye at room temperature. We also prepared a fluorescence ratiometric nano-pH sensor based on dual-fluorophore-doped silica nanoparticles. These newly prepared nanoparticles have been tested for pH determination in real water samples with good results. The methods in this paper proved to be simple, rapid, and specific, and the recovery and relative standard deriation are very satisfactory.(2) http://www.999magnet.com/ Under ultrasonic irradiation, we successfully synthesized Tb-Eu/acac / PAM composite nanoparticles. The synthesis of these nanoparticles led to a particularly simple, inexpensive and sensitive method. These nanoparticles are highly resistant to photobleaching and emit narrow and steady fluorescence and employed as a fluorescence probe for the determination of proteins.
Though traditional fluorescence analytical methods have excellent luminescence properties including good selectivity and sensitivity, steady fluorescence and convenient preparation, they still have some insurmountable disfigurements, such as photo bleaching of majority fluorescence reagent, unsteadiness of fluorescence signal, the side effect of fluorescence reagent to body cells. So we prepared steady composite nanoparticles as the fluorescence probes for the determination of trace substance with the advantages of easy preparation and good dispersity.In this Block Neodymium magnets paper, we successfully prepared composite fluorescence nanoparticles and use them as fluorescence probes to determine proteins and pH. The details are summarized as follows:(1) Water-in-oil microemulsion is a widely used method of preparing nanomaterials of small size. With this reversed micelles method, we prepared nano-pH sensor based on fluorescent silica nanoparticles developed by encapsulating dye at room temperature. We also prepared a fluorescence ratiometric nano-pH sensor based on dual-fluorophore-doped silica nanoparticles. These newly prepared nanoparticles have been tested for pH determination in real water samples with good results. The methods in this paper proved to be simple, rapid, and specific, and the recovery and relative standard deriation are very satisfactory.(2) http://www.999magnet.com/ Under ultrasonic irradiation, we successfully synthesized Tb-Eu/acac / PAM composite nanoparticles. The synthesis of these nanoparticles led to a particularly simple, inexpensive and sensitive method. These nanoparticles are highly resistant to photobleaching and emit narrow and steady fluorescence and employed as a fluorescence probe for the determination of proteins.
Preparation and Analytical Application of Functionalized Magnetic @ Fluorescent Nanocomposites
Preparation and Analytical Application of Functionalized Magnetic @ Fluorescent Nanocomposites
Due to high sensitivity, good selectivity, simple manipulation, and good reproducibility. Fluoremery has attracted more and more attention in different research areas, such as, biochemistry, physics, industry and chemistry. However, the number of molecules with fluorescent properties is very small, which restricts the application of direct fluoremetry. Therefore, it is very important to design and synthesize fluorescent reagents with good fluorescent properties, and thereby to establish sensitive to extend the application of fluoremetry in various scientific disciplines.Magnetic Segment neodymium magnets nanoparticles possess some distinguished characteristics, such as, high specific surface area and easy to separate. In addition, they can be endowed with different functional groups, such as, -COOH, -OH, -CHO, -ArCH2Cl, -NH2 and so on, on surface by coplolymerization or surface chemical modification,In this thesis,
Fe3O4 magnetic nanoparticles as a functional core and fluorescence materials as a shell was chosen to prepare magnetic and luminescent nanocomposites, and thereby use them as fluorescent probes to determine proteins and heavy metal ion. The details are sumarried as follows: (1)Fe3O4/(NaOL/CTAB)n/PABA nanocomposites were prepared by taking advantage of layer-by-layer technique. Then a novel fluorescence method was proposed for the determination of proteins based on the enhancement effect of proteins on the fluorescence of Fe3O4/(NaOL/CTAB)n/PABA nanocomposites. Under optimal conditions, the linear ranges of calibration curves were 0.2-20μg mL-1, 0.2-13μg mL-1, 0.2-10μg mL-1 forγ-globulin (γ-IgG), human serum albumin (HSA), http://www.999magnet.com/
and bovine serum albumin (BSA), respectively. The detection limits were 0.02μg mL-1, 0.01μg mL-1, 0.02μg mL-1 forγ-IgG, HSA and BSA, respectively.(2) Magnetic and luminescent nanocomposites Fe3O4/Py/PAM was prepared by adsorption under ultrasonic irradiation. The reaction between the functional composite nanomaterials was observed and Cr (VI) by Fluorescence spectrum, and then a sensitive FL method for the determination of Cr (VI) was established.(3) Y2O3:Ln3+ (Ln3+=Eu3+, Tb3+, Yb/Er3+) nanocrystals were prepared by solvent method. They are characterized by TEM images, XRD and Fluorescence spectra. The fluorescence properties in different polarity solvent were also investigated.
Due to high sensitivity, good selectivity, simple manipulation, and good reproducibility. Fluoremery has attracted more and more attention in different research areas, such as, biochemistry, physics, industry and chemistry. However, the number of molecules with fluorescent properties is very small, which restricts the application of direct fluoremetry. Therefore, it is very important to design and synthesize fluorescent reagents with good fluorescent properties, and thereby to establish sensitive to extend the application of fluoremetry in various scientific disciplines.Magnetic Segment neodymium magnets nanoparticles possess some distinguished characteristics, such as, high specific surface area and easy to separate. In addition, they can be endowed with different functional groups, such as, -COOH, -OH, -CHO, -ArCH2Cl, -NH2 and so on, on surface by coplolymerization or surface chemical modification,In this thesis,
Fe3O4 magnetic nanoparticles as a functional core and fluorescence materials as a shell was chosen to prepare magnetic and luminescent nanocomposites, and thereby use them as fluorescent probes to determine proteins and heavy metal ion. The details are sumarried as follows: (1)Fe3O4/(NaOL/CTAB)n/PABA nanocomposites were prepared by taking advantage of layer-by-layer technique. Then a novel fluorescence method was proposed for the determination of proteins based on the enhancement effect of proteins on the fluorescence of Fe3O4/(NaOL/CTAB)n/PABA nanocomposites. Under optimal conditions, the linear ranges of calibration curves were 0.2-20μg mL-1, 0.2-13μg mL-1, 0.2-10μg mL-1 forγ-globulin (γ-IgG), human serum albumin (HSA), http://www.999magnet.com/
and bovine serum albumin (BSA), respectively. The detection limits were 0.02μg mL-1, 0.01μg mL-1, 0.02μg mL-1 forγ-IgG, HSA and BSA, respectively.(2) Magnetic and luminescent nanocomposites Fe3O4/Py/PAM was prepared by adsorption under ultrasonic irradiation. The reaction between the functional composite nanomaterials was observed and Cr (VI) by Fluorescence spectrum, and then a sensitive FL method for the determination of Cr (VI) was established.(3) Y2O3:Ln3+ (Ln3+=Eu3+, Tb3+, Yb/Er3+) nanocrystals were prepared by solvent method. They are characterized by TEM images, XRD and Fluorescence spectra. The fluorescence properties in different polarity solvent were also investigated.
The Geological-Geochemical Characteristics and the Structural Significance of the Xinghuadukou Rock Group of Paleoproterozoic in Heihe Area
The Geological-Geochemical Characteristics and the Structural Significance of the Xinghuadukou Rock Group of Paleoproterozoic in Heihe Area
The Xinghuadukou Group (Pt1xh) is the oldest sedimentary record in the research area, which constituted the ancient crystal basement of Precambrian. It was named by Xu Lie in 1960, the era is Early Proterozoic. It was classified as the Xinghua group and the Xing’an Bridge Group in 1979. There was different idea about the group according to the 1:200,000 regional geological survey projects completed in 80-90’s. It was named "Surface Crust Rock" under 1:50,000 regional geological survey and "Xinghuadukou Rock Group (Pt2xh)" under 1:250,000 regional geological survey by the mapping method of "structure - stratum". So it belonged to Mesoproterozoic Era based on its isotopic age. The book, Geology of Heilongjiang Province, published in 1993 only Special shape NdFeB magnets summarizes the 1:200,000 information of research area. The book, Cleaning Up of Rock Stratum in Heilongjiang Province, published in 1997 also didn’t refer the group. It is necessary to use the latest achievements to have a new awareness of Xinghuadukou Rock Group, to determine its era, the formation setting, the correlation of formation with Songnen Plate and so on; Furthermore, we can discuss the questions of structure nature and evolution in the Precambrian. The 1: 250,000 regional geological survey and revision survey which are carrying on at present has obtained massive information of petrology, petrochemistry, geochemistry, mineral composition, and isotope and so on.. It can provide reliable data to study the Xinghuadukou Group.
The study of petrology was carried out using the "structure - stratum" mapping method in exposed. Paleoproterozoic Xinghuadukou Rock Group in Heihe region. The results showed that Xinghuadukou Rock Group was composed mainly of the anorthosite-amphibolite, the gneiss, the leptynite, the schist, the marble and so on. It assumes that the inclusion are always in the shape of island and they“float”in the intrusive rock or assume the tectonic plate in the nappe structure zone. It is called“Xinghuadukou Rock Group”in contrast with Xinghuadukou Group. The original rock is a series of metamorphic basic-intermediate volcanic rocks and the metamorphic sedimentary rocks series which is made up by volcano - sedimentary formation. The stratum belongs to mesoproterozoic according to the isotopic age (Sm-Nd: 1252-1729Ma) of 1:200,000 and 1:250,000 regional geological survey from 90’s. 1:250,000 Xinglong region obtains 2178Ma (Sm-Nd) the pattern age according to the latest research results, Contrasting with the series of rocks Xingdong Group(Pt1x)in Bindong area and Baoyintu Group(Pt1b)in Inner Mongolian area, the age of the stratum was belong to Paleoproterozoic.Petrochemistry data indicated that anorthosite-amphibolite, SiO2=44.662.84%, Na2O>K2O,Al2O3=13.5317.39%,MgO2=47.1271.63%, Al2O3=12.1918.3%, MgO2O>K2O,or Na2O2O; Theschist, SiO2=55.82 75.54%, Al2O3=10.92 20.96%, Na2O > K2O, or Na2O < K2O.SiO2 is generally higher, Al2O3 is lower and Na2O is higher in contrast with North American shale and Australian shale of Achaean. In marble, CaO > MgO.The result showed that the types of oriental rock include basalt, andesite, dacite, tuff, shale sandstone, and mudstone, carbonate rocks and so on. Rock composition and division series were carried through with preexistent rock is basalt rock., including alkalinity series and sub-alkalinity series.Geochemistry characteristics of volcanic rock of Xinghuadukou Rock Group are as followed:∑REE=150200×10-6, LREE/HREE=4.576.26,δEu=0.560.79 is medium negative exceptionally. Distribution patterns show the character that LREE concentrated, HREE lost, Eu negative exceptionally. It is also showing a right inclining current that right side is low and the left is high and a similar distribution model. That may be the result of http://www.999magnet.com/ homologous differentiation. The trace element oceanic ridge basalts standardization diagram assumes obviously three apophyses patterns. Large ion element such as Sr, K, Rb, Ba, Th, Ta concentrate and simultaneously Ce, P, Zr, Hf, Sm also relatively concentrate.
Ti, Y, Yb, Sc, Cr, and other elements are loss. The curve are similar with the curve of Chile island arc calcium alkalinity basalt.In the samples whose preexistent sedimentary ,∑REE=126190×10-6,that is similar with the Russian platform mudstone and Guangdong Luoding sillimanite schist .LREE/HREE=4.75 to 8.06,δEu=0.64-0.84 is for the weak Eu negative abnormal. Distribution patterns show LREE enrichment, HREE loss, the feature of Eu negative anomaly; it also shows low left high right - right tilt, and the original rock and the distribution model are similar with the volcanic rocks. In this area, Gd/Yb ratio generally is more than 2.0 which shows the mother rock of source area oldest rock in the region. The trace element oceanic ridge basalts standardized graphical displays that large ion elements Sr, K, Rb, Ba, Th, concentrate, Nb, Ce, P, Zr, Hf, Sm also relatively concentrate simultaneously. Ti, Y, Yb, Sc, Cr, and other elements are losses. The curve was similar with which of the volcanic rock.Thus the material origin was connected with the volcanic rock..Mudstone can be classifed garnet zone, staurolite zone, basic rocks can be classifed plagioclase-hornblende belt according to the characteristic of metamorphic mineral combination. Plagioclase is andesine according to electron microprobe analysis of the chemical constituents; biotite is lepdomelane, it is belong to the amphibolite facies; amphibole is hornblende in calcium amphibole group of magnesium;The more aluminum the 4 coordinates Hornblende contains, the higher the temperature reflects; Garnet is manganese aluminum garnet of almandine garnet, which explained metamorphic temperature is located the low temperature part contrast to hornblende. The chemical composition diagram falls the kyanite belt and the amphibolite facies. According to the mineral ingredient estimate metamorphic the temperature and pressure conditions: T=450650℃, P=0.20.6GPa. It is the region power heat flow metamorphism product.The level of metamorphism is amphibolite facies which belongs to middle P/T types.According to the content of trace elements, such as B, Cr, Cu, Ni, V, and the ratio of Sr / Ba and Mg/Al, it reflects land-sea transition and sea water sedimentary environment. According to the ratio of V/Cr, Ni/Co, the U/Th, it shows the neritic environment which it forms are possibly rich of oxygen. According to the ratio of Th/Co, Th/Cr, the Cr/Zr, the source rocks are felsic rock and basic rock.The study of the ratio of trace elements and major elements showed that the basalt of the Xinghuadukou Rock Group reflects complex tectonic setting which includes the ocean floor of basalt, mainland volcanic rock, island arc of calcium alkali basalt and also potassium basalt rock.
They are close paragenesis in space, that shows that it was ocean basin environment in Heihe region in the Proterozoic Era. But the island basalt and Special shape NdFeB magnets potassium basalt are volcanic rocks above the eruption to the ocean floor basalt or island arc. It relative to the magma caused by mantle plume(hot spot).However the active continental margin or the mainland island arc area of structural environment which sedimetary rock categories reflect has explained the ingredient characteristics: the composition set of metasedimentary rocks between the mainland island margin argillaceous sandstone should belong to the transitional types of clastic sedimentary rocks.The study of petrology and geochemistry of the Xinghuadukou Rock Group showed that in Proterozoic, Heihe area is related to a land-based source - formation of island-arc deposition, the rock combination which is with the mantle plume (hot spot) activities. It is also a combination of magma ocean floor basalt, volcanic island arc basalt, and different tectonic setting. The primitive environment could possibly be ocean basin environment with multi-islands. It indicated something by development in various combinations between the rock and the existence of the internal faults, as well as the characteristics which happened after the rock experiences the function of amphibolite facies. The rocks are formed under several different tectonic setting are joined together in the same place by the multi-islands ocean basin which is reduced with long complex structure process of oceanic crust and the arc–continenta collision.
The Xinghuadukou Group (Pt1xh) is the oldest sedimentary record in the research area, which constituted the ancient crystal basement of Precambrian. It was named by Xu Lie in 1960, the era is Early Proterozoic. It was classified as the Xinghua group and the Xing’an Bridge Group in 1979. There was different idea about the group according to the 1:200,000 regional geological survey projects completed in 80-90’s. It was named "Surface Crust Rock" under 1:50,000 regional geological survey and "Xinghuadukou Rock Group (Pt2xh)" under 1:250,000 regional geological survey by the mapping method of "structure - stratum". So it belonged to Mesoproterozoic Era based on its isotopic age. The book, Geology of Heilongjiang Province, published in 1993 only Special shape NdFeB magnets summarizes the 1:200,000 information of research area. The book, Cleaning Up of Rock Stratum in Heilongjiang Province, published in 1997 also didn’t refer the group. It is necessary to use the latest achievements to have a new awareness of Xinghuadukou Rock Group, to determine its era, the formation setting, the correlation of formation with Songnen Plate and so on; Furthermore, we can discuss the questions of structure nature and evolution in the Precambrian. The 1: 250,000 regional geological survey and revision survey which are carrying on at present has obtained massive information of petrology, petrochemistry, geochemistry, mineral composition, and isotope and so on.. It can provide reliable data to study the Xinghuadukou Group.
The study of petrology was carried out using the "structure - stratum" mapping method in exposed. Paleoproterozoic Xinghuadukou Rock Group in Heihe region. The results showed that Xinghuadukou Rock Group was composed mainly of the anorthosite-amphibolite, the gneiss, the leptynite, the schist, the marble and so on. It assumes that the inclusion are always in the shape of island and they“float”in the intrusive rock or assume the tectonic plate in the nappe structure zone. It is called“Xinghuadukou Rock Group”in contrast with Xinghuadukou Group. The original rock is a series of metamorphic basic-intermediate volcanic rocks and the metamorphic sedimentary rocks series which is made up by volcano - sedimentary formation. The stratum belongs to mesoproterozoic according to the isotopic age (Sm-Nd: 1252-1729Ma) of 1:200,000 and 1:250,000 regional geological survey from 90’s. 1:250,000 Xinglong region obtains 2178Ma (Sm-Nd) the pattern age according to the latest research results, Contrasting with the series of rocks Xingdong Group(Pt1x)in Bindong area and Baoyintu Group(Pt1b)in Inner Mongolian area, the age of the stratum was belong to Paleoproterozoic.Petrochemistry data indicated that anorthosite-amphibolite, SiO2=44.662.84%, Na2O>K2O,Al2O3=13.5317.39%,MgO2=47.1271.63%, Al2O3=12.1918.3%, MgO2O>K2O,or Na2O2O; Theschist, SiO2=55.82 75.54%, Al2O3=10.92 20.96%, Na2O > K2O, or Na2O < K2O.SiO2 is generally higher, Al2O3 is lower and Na2O is higher in contrast with North American shale and Australian shale of Achaean. In marble, CaO > MgO.The result showed that the types of oriental rock include basalt, andesite, dacite, tuff, shale sandstone, and mudstone, carbonate rocks and so on. Rock composition and division series were carried through with preexistent rock is basalt rock., including alkalinity series and sub-alkalinity series.Geochemistry characteristics of volcanic rock of Xinghuadukou Rock Group are as followed:∑REE=150200×10-6, LREE/HREE=4.576.26,δEu=0.560.79 is medium negative exceptionally. Distribution patterns show the character that LREE concentrated, HREE lost, Eu negative exceptionally. It is also showing a right inclining current that right side is low and the left is high and a similar distribution model. That may be the result of http://www.999magnet.com/ homologous differentiation. The trace element oceanic ridge basalts standardization diagram assumes obviously three apophyses patterns. Large ion element such as Sr, K, Rb, Ba, Th, Ta concentrate and simultaneously Ce, P, Zr, Hf, Sm also relatively concentrate.
Ti, Y, Yb, Sc, Cr, and other elements are loss. The curve are similar with the curve of Chile island arc calcium alkalinity basalt.In the samples whose preexistent sedimentary ,∑REE=126190×10-6,that is similar with the Russian platform mudstone and Guangdong Luoding sillimanite schist .LREE/HREE=4.75 to 8.06,δEu=0.64-0.84 is for the weak Eu negative abnormal. Distribution patterns show LREE enrichment, HREE loss, the feature of Eu negative anomaly; it also shows low left high right - right tilt, and the original rock and the distribution model are similar with the volcanic rocks. In this area, Gd/Yb ratio generally is more than 2.0 which shows the mother rock of source area oldest rock in the region. The trace element oceanic ridge basalts standardized graphical displays that large ion elements Sr, K, Rb, Ba, Th, concentrate, Nb, Ce, P, Zr, Hf, Sm also relatively concentrate simultaneously. Ti, Y, Yb, Sc, Cr, and other elements are losses. The curve was similar with which of the volcanic rock.Thus the material origin was connected with the volcanic rock..Mudstone can be classifed garnet zone, staurolite zone, basic rocks can be classifed plagioclase-hornblende belt according to the characteristic of metamorphic mineral combination. Plagioclase is andesine according to electron microprobe analysis of the chemical constituents; biotite is lepdomelane, it is belong to the amphibolite facies; amphibole is hornblende in calcium amphibole group of magnesium;The more aluminum the 4 coordinates Hornblende contains, the higher the temperature reflects; Garnet is manganese aluminum garnet of almandine garnet, which explained metamorphic temperature is located the low temperature part contrast to hornblende. The chemical composition diagram falls the kyanite belt and the amphibolite facies. According to the mineral ingredient estimate metamorphic the temperature and pressure conditions: T=450650℃, P=0.20.6GPa. It is the region power heat flow metamorphism product.The level of metamorphism is amphibolite facies which belongs to middle P/T types.According to the content of trace elements, such as B, Cr, Cu, Ni, V, and the ratio of Sr / Ba and Mg/Al, it reflects land-sea transition and sea water sedimentary environment. According to the ratio of V/Cr, Ni/Co, the U/Th, it shows the neritic environment which it forms are possibly rich of oxygen. According to the ratio of Th/Co, Th/Cr, the Cr/Zr, the source rocks are felsic rock and basic rock.The study of the ratio of trace elements and major elements showed that the basalt of the Xinghuadukou Rock Group reflects complex tectonic setting which includes the ocean floor of basalt, mainland volcanic rock, island arc of calcium alkali basalt and also potassium basalt rock.
They are close paragenesis in space, that shows that it was ocean basin environment in Heihe region in the Proterozoic Era. But the island basalt and Special shape NdFeB magnets potassium basalt are volcanic rocks above the eruption to the ocean floor basalt or island arc. It relative to the magma caused by mantle plume(hot spot).However the active continental margin or the mainland island arc area of structural environment which sedimetary rock categories reflect has explained the ingredient characteristics: the composition set of metasedimentary rocks between the mainland island margin argillaceous sandstone should belong to the transitional types of clastic sedimentary rocks.The study of petrology and geochemistry of the Xinghuadukou Rock Group showed that in Proterozoic, Heihe area is related to a land-based source - formation of island-arc deposition, the rock combination which is with the mantle plume (hot spot) activities. It is also a combination of magma ocean floor basalt, volcanic island arc basalt, and different tectonic setting. The primitive environment could possibly be ocean basin environment with multi-islands. It indicated something by development in various combinations between the rock and the existence of the internal faults, as well as the characteristics which happened after the rock experiences the function of amphibolite facies. The rocks are formed under several different tectonic setting are joined together in the same place by the multi-islands ocean basin which is reduced with long complex structure process of oceanic crust and the arc–continenta collision.
Study on the Diastereoselectivity Diels-Alder Reaction and Biginelli-type Condensation Reaction Catalyzed by Lanthanide Halides
Study on the Diastereoselectivity Diels-Alder Reaction and Biginelli-type Condensation Reaction Catalyzed by Lanthanide Halides
The lanthanide halides catalyzed syntheses of several kinds of azaheterocycle arestudied in this thesis, which is composed with three parts as follows:1. Samarium diiodid is found to be an efficient catalyst in the three-component iminoDiels-Alder reaction of aromatic aldehyde, aromatic amine with dihydropyran ordihydrofuran to afford pyrano[3,2-c]-or furano[3,2-c]quinoline in good yields with highstereoselectivity. Either of the cis and trans isomers can be obtained as the major productby changing the reaction conditions conveniently. Higher temperature and lower Neodymium Magnets substrateconcentration give more the thermodynamic stable trans products, and lower temperatureand higher substrate concentration lead to a fast formation of the kinetically favored cisproducts.2. The Biginelli-type condensation of aromatic aldehyde, urea or thiourea withcyclopentanone is effectively catalyzed by hydrated ytterbium chloride (YbCl3·nH2O)affording benzylidene hctcrobicyclic pyrimidine-2-one in moderate to excellent yields. Thereaction can proceed smoothly in the absence of solvent in the atmosphere withoutrigorous exclusion of oxygen and moisture.In addition, the nitro-Mannich reaction http://www.999magnet.com/ of nitroethane with sulfonylimine catalyzed byYb(OiPr)3-cinchonine is explored.
The lanthanide halides catalyzed syntheses of several kinds of azaheterocycle arestudied in this thesis, which is composed with three parts as follows:1. Samarium diiodid is found to be an efficient catalyst in the three-component iminoDiels-Alder reaction of aromatic aldehyde, aromatic amine with dihydropyran ordihydrofuran to afford pyrano[3,2-c]-or furano[3,2-c]quinoline in good yields with highstereoselectivity. Either of the cis and trans isomers can be obtained as the major productby changing the reaction conditions conveniently. Higher temperature and lower Neodymium Magnets substrateconcentration give more the thermodynamic stable trans products, and lower temperatureand higher substrate concentration lead to a fast formation of the kinetically favored cisproducts.2. The Biginelli-type condensation of aromatic aldehyde, urea or thiourea withcyclopentanone is effectively catalyzed by hydrated ytterbium chloride (YbCl3·nH2O)affording benzylidene hctcrobicyclic pyrimidine-2-one in moderate to excellent yields. Thereaction can proceed smoothly in the absence of solvent in the atmosphere withoutrigorous exclusion of oxygen and moisture.In addition, the nitro-Mannich reaction http://www.999magnet.com/ of nitroethane with sulfonylimine catalyzed byYb(OiPr)3-cinchonine is explored.
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