Study on Simulation and Fabrication of MEMS Solenoid Microinductor with Magnetic Core
Great numbers of separate RF (Radio-Frequency) components in wireless communication systems nowadays have impeded the realization of SOC (System-On-Chip), which is the ultimate goal of miniaturized wireless terminals with high performance and lost cost. The rapid development of MEMS (Micro Electro-Mechanical System) technology in recent years has established itself as a reliable and effective methodology of building micro systems on silicon. As a result, neodymium magnets various RF and magnetic components based on MEMS technology have become wildly-concerned topics to researchers.According to the world’s development of microinductors nowadays, this thesis presents two physical models: a FE (Finite Element) model built with ANSYS as well as a numerical model built based on electromagnetic theory. With these two models, detailed analysis of effects of various factors on performance of microinductor is performed. Microinductor is fabricated by MEMS and tested. Two physical models are compared with experiment, and a possible optimization plan of the inductor is proposed. Key work and conclusions of this thesis are listed as below:(1) Analysis of solenoid microinductor with magnetic core by ANSYS This thesis builds a finite element model of solenoid microinductor with magnetic core based on edge-based 3-dimensional harmonic electromagnetic analysis of ANSYS.
Distribution of magnetic field within the microinductor is acquired. And with the calculated result of stored energy and power loss, we further obtain the equivalent inductance and resistance of the magnetic core.(2) A numerical model of solenoid microinductor with magnetic core A numerical model of solenoid microinductor with magnetic core on the basis of classical neodymium magnets electromagnetic theory is also presented and realized by MatLab programming in this thesis. Agreement of numerical results, ANSYS analysis and experimental measurements is obtained. And within a 4mm by 4mm area, specific analysis is performed in two aspects from material characteristics to geometrical parameters, and in four parts that are coil, magnetic core, insulation material and substrate. With the result acquired, an optimized designing plan is proposed.(3) Fabrication and measurement of solenoid microinductor with magnetic core Solenoid microinductors with NiFe thin film magnetic core are designed and fabricated using MEMS technology. MEMS techniques such as sputtering, lithography, electroplating, dry and wet etching are involved as well as a series of key fabrication technologies such as double-side mask alignment, multilevel metallization, deep photolithography and electroplating, polyimide insulation and fine polishing. Measurements of inductance and quality factor (Q) are carried out 1-10 MHz http://www.chinamagnets.biz/ with Agilent E4991A Impedance/Material Analyzer. According to the obtained data, increase of magnetic core thickness can enhance the inductance of a solenoid microinductor with NiFe magnetic core with sacrificing of Q factor.
2012年3月26日星期一
Studies on the Synthesis, Crystal Structures, Spectroscopic Characterization and Magnetic Properties
Studies on the Synthesis, Crystal Structures, Spectroscopic Characterization and Magnetic Properties of Complexes of Tetrazole-1-acetic Acid
In this dissertation, fourteen new coordination complexes have been synthesized by the liquid method. They were studied by IR, Elemental Analysis and single crystal X-ray diffraction methods. The magnetic properties of polymers (1) to (4) and the fluorescence spectra data of polymers (7) and (8) are measured.The ligand we used is tetrazole-1-acetic acid (Htza), and it has several coordination modes in this dissertation, as follows:There are three rare earth magnets chapters in this dissertation:Chapter one: Five new complexes of Htza with Cu(II) are synthesized by controlling the pH value of the reaction system or adding the second ligand. They are {[Cu(tza)2(Htza)2]·2H2O}n (1), [Cu(tza)2]n (2), {[Cu2(tza)2(CH3COO)(μ3-OH)(H2O)]·H2O}n (3), [Cu2(tza)3(μ3-OH) 2H2O]n (4), {[Cu(tza)(phen)](ClO4)}n (5). The pH value of the reaction system from (1) to (4) is 2.02.5, 3.0, 3.87, 5.5, respectively. The ligands coordinate with Cu(II) ions via (b) and (c) in complex (1), and the Cu(II) ions are connected to 1-D chain structure. Then, the neighboring chains are assembled to 2-D network structure by hydrogen bonds. In complex (2), the ligands coordinate with Cu(II) ions by (d), and the Cu(II) ions are linked into 2-D network structure. There are twoμ3-OH in one structural cell of complex (3), and four Cu(II) ions are connected by them. Then, the structural cells are linked into 2-D network structure by (d) and (i), and the 2-D network structure is assembled to 3-D meshwork structure via hydrogen bonds.
The structure of complex (4) is similar to complex (3). But, there is CH3COO- in complex (3). And the Cu(II) ions of complex (4) are connected to 2-D network structure by (c), (d) and (e).In complex (5), the phen is added in order to study the influence of the rare earth magnets second ligand on the complex structure. The spacial resistance is enhanced because the phen coordinates with Cu(II). So the Cu(II) ions of complex (5) are only linked into 1-D z chain structure via (e). Complex (1), (2), (4), (5) belong to monoclinic system, space groups are C2/c, P2(1)/c, P2(1)/n, C2/c, respectively. Complex (3) belongs to Triclinic, space group P-1. Chapter two: Five new polymers are synthesized by reaction of Htza with oxides of Zn, Cd, Pb and perchlorides of Cd, Co in this part. They are [Zn2(tza)3(μ3-OH)(H2O)·2H2O]n (6), [Cd(tza)2]n (7), {[Cd(tza)(2,2?-bipy)(H2O)](ClO4)}n (8), {[Co(tza)(2,2?-bipy)(H2- O)](ClO4)}n (9), [Pb(tza)2]n (10). We study the influence of the second ligand and different metallic ions on the complex structure. In complex (6), the Zn(II) ions are connected to 2-D network structure by (c), (e) and (h). But in complex (7), the ligands link Cd(II) ions into 3-D meshwork structure polymer only via (e). In complex (8), 2,2?-bipy is added and the Cd(II) ions are connected to 2-D network structure by (e). The extension of complex (8) along a axis is limited because the 2,2?-bipy coordinates with Cd(II) ions . But the neighboring planes are assembled into 3-D meshwork supermolecular structure via hydrogen bonds andπ-πstacking. The configuration of Co(II) ions in complex (9) is the same as Cd(II) ions in complex (8). But the corresponding bond length varies a little. In complex (10), the ligands link Pb(II) ions into 1-D chain structure by (f). The Pb(II) ions have two tropism in one chain, and the rare earth magnets neighboring Pb(II) ions have Pb-O···Pb weak interaction in adajacent chains.
The complex (10) is assembled into 3-D meshwork supermolecular structure by that weak interaction.Complex (6) belongs to Triclinic system, space group P-1. Complex (7) to (10) belong to monoclinic system, and space groups are P2(1)/n、P2(1)/c、P2(1)/c、C2/c, respectively.Chapter three: Four new rare earth polymers are synthesized by reaction of Htza with oxides of rare earth. They are [La(tza)3(H2O)2·2H2O]n (11), [Pr(tza)3(H2O)2·2H2O]n (12), [Nd (tza)3(H2O)2·1.5H2O]n (13), [Sm2(tza)6(H2O)5·H2O]n (14). The configuration of metal ions are the same in complex (11) and (12), and the metal ions are connected to 1-D chain structure via (c) and (g). Then, the chains are assembled into 3-D meshwork supermolecular structure by hydrogen bonds. In complex (13), the configuration of Nd(III) ions is the same as complex (11) and (12), but the http://www.chinamagnets.biz/ arrangement of ligands is changed. There are two kinds of Sm(III) ions in complex (14). The configuration of Sm(III)1 ions is the same as Nd(III) ions in complex (13), but the Sm(III)2 ions are eight-coordinated and they are dinuclear cells. Adjacent dinuclear cells are linked into 2-D network structure by intermolecular hydrogen bonds. Then, the chains of Sm(III)1 and the 2-D network structure of Sm(III)2 are assembled into 3-D meshwork supermolecular structure.Complex (11) and (12) belong to monoclinic system, space groups are all P2(1)/c; Complex (13) and (14) belong to Triclinic system, space groups are all P-1.Variable-temperature magnetic susceptibility of complexes (1) to (4) were performed in the 2320 K region by using powder samples. The antiferromagnetic interaction among the metal ions are evident from the susceptibility data in complex (1) and ferromagnetic interaction in complex (2); And the pure antiferromagnetic interactions are showed in complex (3) and (4).At room temperature, the fluorescence of complex (7) and (8) are measured in the solid state on the same condition. There is no fluorescence emission in complex (7). While complex (8) shows the fluorescence emission withλem = 445 nm (λex = 397 nm). The emission observed in complex (8) is tentatively assigned to the ligands fluorescence(LLCT).
In this dissertation, fourteen new coordination complexes have been synthesized by the liquid method. They were studied by IR, Elemental Analysis and single crystal X-ray diffraction methods. The magnetic properties of polymers (1) to (4) and the fluorescence spectra data of polymers (7) and (8) are measured.The ligand we used is tetrazole-1-acetic acid (Htza), and it has several coordination modes in this dissertation, as follows:There are three rare earth magnets chapters in this dissertation:Chapter one: Five new complexes of Htza with Cu(II) are synthesized by controlling the pH value of the reaction system or adding the second ligand. They are {[Cu(tza)2(Htza)2]·2H2O}n (1), [Cu(tza)2]n (2), {[Cu2(tza)2(CH3COO)(μ3-OH)(H2O)]·H2O}n (3), [Cu2(tza)3(μ3-OH) 2H2O]n (4), {[Cu(tza)(phen)](ClO4)}n (5). The pH value of the reaction system from (1) to (4) is 2.02.5, 3.0, 3.87, 5.5, respectively. The ligands coordinate with Cu(II) ions via (b) and (c) in complex (1), and the Cu(II) ions are connected to 1-D chain structure. Then, the neighboring chains are assembled to 2-D network structure by hydrogen bonds. In complex (2), the ligands coordinate with Cu(II) ions by (d), and the Cu(II) ions are linked into 2-D network structure. There are twoμ3-OH in one structural cell of complex (3), and four Cu(II) ions are connected by them. Then, the structural cells are linked into 2-D network structure by (d) and (i), and the 2-D network structure is assembled to 3-D meshwork structure via hydrogen bonds.
The structure of complex (4) is similar to complex (3). But, there is CH3COO- in complex (3). And the Cu(II) ions of complex (4) are connected to 2-D network structure by (c), (d) and (e).In complex (5), the phen is added in order to study the influence of the rare earth magnets second ligand on the complex structure. The spacial resistance is enhanced because the phen coordinates with Cu(II). So the Cu(II) ions of complex (5) are only linked into 1-D z chain structure via (e). Complex (1), (2), (4), (5) belong to monoclinic system, space groups are C2/c, P2(1)/c, P2(1)/n, C2/c, respectively. Complex (3) belongs to Triclinic, space group P-1. Chapter two: Five new polymers are synthesized by reaction of Htza with oxides of Zn, Cd, Pb and perchlorides of Cd, Co in this part. They are [Zn2(tza)3(μ3-OH)(H2O)·2H2O]n (6), [Cd(tza)2]n (7), {[Cd(tza)(2,2?-bipy)(H2O)](ClO4)}n (8), {[Co(tza)(2,2?-bipy)(H2- O)](ClO4)}n (9), [Pb(tza)2]n (10). We study the influence of the second ligand and different metallic ions on the complex structure. In complex (6), the Zn(II) ions are connected to 2-D network structure by (c), (e) and (h). But in complex (7), the ligands link Cd(II) ions into 3-D meshwork structure polymer only via (e). In complex (8), 2,2?-bipy is added and the Cd(II) ions are connected to 2-D network structure by (e). The extension of complex (8) along a axis is limited because the 2,2?-bipy coordinates with Cd(II) ions . But the neighboring planes are assembled into 3-D meshwork supermolecular structure via hydrogen bonds andπ-πstacking. The configuration of Co(II) ions in complex (9) is the same as Cd(II) ions in complex (8). But the corresponding bond length varies a little. In complex (10), the ligands link Pb(II) ions into 1-D chain structure by (f). The Pb(II) ions have two tropism in one chain, and the rare earth magnets neighboring Pb(II) ions have Pb-O···Pb weak interaction in adajacent chains.
The complex (10) is assembled into 3-D meshwork supermolecular structure by that weak interaction.Complex (6) belongs to Triclinic system, space group P-1. Complex (7) to (10) belong to monoclinic system, and space groups are P2(1)/n、P2(1)/c、P2(1)/c、C2/c, respectively.Chapter three: Four new rare earth polymers are synthesized by reaction of Htza with oxides of rare earth. They are [La(tza)3(H2O)2·2H2O]n (11), [Pr(tza)3(H2O)2·2H2O]n (12), [Nd (tza)3(H2O)2·1.5H2O]n (13), [Sm2(tza)6(H2O)5·H2O]n (14). The configuration of metal ions are the same in complex (11) and (12), and the metal ions are connected to 1-D chain structure via (c) and (g). Then, the chains are assembled into 3-D meshwork supermolecular structure by hydrogen bonds. In complex (13), the configuration of Nd(III) ions is the same as complex (11) and (12), but the http://www.chinamagnets.biz/ arrangement of ligands is changed. There are two kinds of Sm(III) ions in complex (14). The configuration of Sm(III)1 ions is the same as Nd(III) ions in complex (13), but the Sm(III)2 ions are eight-coordinated and they are dinuclear cells. Adjacent dinuclear cells are linked into 2-D network structure by intermolecular hydrogen bonds. Then, the chains of Sm(III)1 and the 2-D network structure of Sm(III)2 are assembled into 3-D meshwork supermolecular structure.Complex (11) and (12) belong to monoclinic system, space groups are all P2(1)/c; Complex (13) and (14) belong to Triclinic system, space groups are all P-1.Variable-temperature magnetic susceptibility of complexes (1) to (4) were performed in the 2320 K region by using powder samples. The antiferromagnetic interaction among the metal ions are evident from the susceptibility data in complex (1) and ferromagnetic interaction in complex (2); And the pure antiferromagnetic interactions are showed in complex (3) and (4).At room temperature, the fluorescence of complex (7) and (8) are measured in the solid state on the same condition. There is no fluorescence emission in complex (7). While complex (8) shows the fluorescence emission withλem = 445 nm (λex = 397 nm). The emission observed in complex (8) is tentatively assigned to the ligands fluorescence(LLCT).
Bulk Undercooling and Directional Growth of Fe-Ga Magnetostractive Alloy
Bulk Undercooling and Directional Growth of Fe-Ga Magnetostractive Alloy
Giant magnetostrictive materials have been widely applied in spaceflight and military field as the element of acoustic sensors, actuators, and other magnetomechanical devices. Recently, Fe-Ga system which is virtue of low-filed magnetostriction and good mechanical properties such as good ductility and high strength, has attracted increasing attentions as magnetostrictive materials. In this study, by way of molten glass denucleating and superheating-cooling cycles, the undercooling behavior of the Fe83Ga17 alloys was studied. The Fe83Ga17 bars with preferred strong magnets orientation were obtained using super-high temperature gradient directional solidification method.The Fe83Ga17 alloys were undercooled up to 287K through molten glass denucleating and superheating-cooling cycles. When the undercooling was less than 54K, the structures were composed of coarse dendrites. With increasing the undercooling up to 216K, the grains were refined. More particularly, the dendrites tended to possess a preferred orientation when the undercooling was in the range of 141-176K. When the undercooling exceeded 252K, abnormal large grains coexisting with fine equiaxed grains appeared. With a further increase of the undercooling up to 287K, only big equiaxed grains existed. The grain refinement with the increasing undercooling is due to the increased nucleation rate as the undercooling was less than 252K. When undercooling exceeded 252K, recrystallization occurred in the melt, giving rise to the strong magnets formation of big grains. Local shot-range ordering of Ga atoms was formed in the Fe83Ga17 alloy when the undercooling exceeded 176K, and the presence of clusters of near-neighbor pairs of Ga atoms contributed to the large magnetostriction.
The quenching process can improve the magnetostriction of Fe83Ga17 alloy by restricting the formation of DO3 phase. In the quenching process, small volume fraction of the b.c.c matrix turned to the Modified-DO3 phase which has pairs of Ga along [100]. On the other hand, in the annealing process, the development of long-rang DO3 structure was formed and the clusters of Ga atoms was disappeared, leading to a decrease in magnetostriction.Using super-high temperature gradient directional solidification method, the Fe83Ga17 alloy bars with [110] orientation were prepared. The experimental temperature gradient was 800K/cm. When the growth velocity was 6μm/s, several coarse columnar crystals along the longitudinal direction and even without transverse strong magnets interfaces were formed in the growth stability area. The preferred orientation of directional solidified sample was interrupted as the growth velocity was 10μm/s. The phenomena were explained by the relationship between growth velocity and the solid-liquid interface shape. In order to prepare samples with preferred orientation, it is necessary to make the growth velocity consistent with the temperature gradient, and to make sure the solid-liquid interface convex.Both bulk undercooling and directional growth can obtain structures with preferred orientation, and most importantly, the undercooling experiment improves the texture of [100] orientation, and provides a possibility to prepare magnetostriction alloys with [100] preferred orientation.
Giant magnetostrictive materials have been widely applied in spaceflight and military field as the element of acoustic sensors, actuators, and other magnetomechanical devices. Recently, Fe-Ga system which is virtue of low-filed magnetostriction and good mechanical properties such as good ductility and high strength, has attracted increasing attentions as magnetostrictive materials. In this study, by way of molten glass denucleating and superheating-cooling cycles, the undercooling behavior of the Fe83Ga17 alloys was studied. The Fe83Ga17 bars with preferred strong magnets orientation were obtained using super-high temperature gradient directional solidification method.The Fe83Ga17 alloys were undercooled up to 287K through molten glass denucleating and superheating-cooling cycles. When the undercooling was less than 54K, the structures were composed of coarse dendrites. With increasing the undercooling up to 216K, the grains were refined. More particularly, the dendrites tended to possess a preferred orientation when the undercooling was in the range of 141-176K. When the undercooling exceeded 252K, abnormal large grains coexisting with fine equiaxed grains appeared. With a further increase of the undercooling up to 287K, only big equiaxed grains existed. The grain refinement with the increasing undercooling is due to the increased nucleation rate as the undercooling was less than 252K. When undercooling exceeded 252K, recrystallization occurred in the melt, giving rise to the strong magnets formation of big grains. Local shot-range ordering of Ga atoms was formed in the Fe83Ga17 alloy when the undercooling exceeded 176K, and the presence of clusters of near-neighbor pairs of Ga atoms contributed to the large magnetostriction.
The quenching process can improve the magnetostriction of Fe83Ga17 alloy by restricting the formation of DO3 phase. In the quenching process, small volume fraction of the b.c.c matrix turned to the Modified-DO3 phase which has pairs of Ga along [100]. On the other hand, in the annealing process, the development of long-rang DO3 structure was formed and the clusters of Ga atoms was disappeared, leading to a decrease in magnetostriction.Using super-high temperature gradient directional solidification method, the Fe83Ga17 alloy bars with [110] orientation were prepared. The experimental temperature gradient was 800K/cm. When the growth velocity was 6μm/s, several coarse columnar crystals along the longitudinal direction and even without transverse strong magnets interfaces were formed in the growth stability area. The preferred orientation of directional solidified sample was interrupted as the growth velocity was 10μm/s. The phenomena were explained by the relationship between growth velocity and the solid-liquid interface shape. In order to prepare samples with preferred orientation, it is necessary to make the growth velocity consistent with the temperature gradient, and to make sure the solid-liquid interface convex.Both bulk undercooling and directional growth can obtain structures with preferred orientation, and most importantly, the undercooling experiment improves the texture of [100] orientation, and provides a possibility to prepare magnetostriction alloys with [100] preferred orientation.
2012年3月18日星期日
分子磁体NaFeⅡ2(PO4)(HPO4)的磁性及电导性的第一性原理研究
分子磁体NaFeⅡ2(PO4)(HPO4)的磁性及电导性的第一性原理研究
In this thesis, first-principle calculations have been performed to study the electronic structure and the magnetic properties of non-pure organic magnet NaFe2Ⅱ(PO4)(HPO4). All calculations were performed using a full potential linearized augmented plane wave (FP-LAPW) method based on the density functional theory (DFT).To test the accuracy and precision of FP-LAPW method, the electronic structure and ferroelectric properties of the simple bulk BaTiO3 neodymium rare earth magnets were first studied. The analysis of the partial density of states indicates that Ti 3d states and O 2p states are greatly overlapped, showing strong hybridization between them.
This orbital hybridization may lead to the spontaneous polarization in octahedron, and it results in aligned electric dipoles in bulk BaTiO3, presenting ferroelectric property. External pressure and temperature can induce ferroelectric phase transition http://www.chinamagnets.biz/ of BaTiO3 because of changed orbital hybridization.For metal phosphonates NaFe2Ⅱ(PO4)(HPO4), a stable antiferromagnetic (AFM) ground state and a ferromagnetic (FM) metastable state were found in agreement with the experimental results. The calculated spin magnetic moment per molecule is 7.00μB, mainly from the FeⅡ. Density of states shows that NaFe2Ⅱ(PO4)(HPO4) is characteristic of semiconductor and conductor in AFM and FM states respectively. In order to further investigate the conductivity properties in FM neodymium rare earth magnets and AFM states, we also give the electronic band structure, it is found that the bands have significant overlaps between the highest occupied molecule orbital (HOMO) and lowest unoccupied molecule orbital (LUMO) of spin-up and spin-down in FM states, while an energy gap of about 0.2eV in AFM states, based on this we can conclude that the FM metastable state has conductor properties, but AFM ground state has semiconductor properties.
In this thesis, first-principle calculations have been performed to study the electronic structure and the magnetic properties of non-pure organic magnet NaFe2Ⅱ(PO4)(HPO4). All calculations were performed using a full potential linearized augmented plane wave (FP-LAPW) method based on the density functional theory (DFT).To test the accuracy and precision of FP-LAPW method, the electronic structure and ferroelectric properties of the simple bulk BaTiO3 neodymium rare earth magnets were first studied. The analysis of the partial density of states indicates that Ti 3d states and O 2p states are greatly overlapped, showing strong hybridization between them.
This orbital hybridization may lead to the spontaneous polarization in octahedron, and it results in aligned electric dipoles in bulk BaTiO3, presenting ferroelectric property. External pressure and temperature can induce ferroelectric phase transition http://www.chinamagnets.biz/ of BaTiO3 because of changed orbital hybridization.For metal phosphonates NaFe2Ⅱ(PO4)(HPO4), a stable antiferromagnetic (AFM) ground state and a ferromagnetic (FM) metastable state were found in agreement with the experimental results. The calculated spin magnetic moment per molecule is 7.00μB, mainly from the FeⅡ. Density of states shows that NaFe2Ⅱ(PO4)(HPO4) is characteristic of semiconductor and conductor in AFM and FM states respectively. In order to further investigate the conductivity properties in FM neodymium rare earth magnets and AFM states, we also give the electronic band structure, it is found that the bands have significant overlaps between the highest occupied molecule orbital (HOMO) and lowest unoccupied molecule orbital (LUMO) of spin-up and spin-down in FM states, while an energy gap of about 0.2eV in AFM states, based on this we can conclude that the FM metastable state has conductor properties, but AFM ground state has semiconductor properties.
Synthesis on Phthalocyanines-based Bifunctional Agents of Contrast Agent for MRI and Photosensitizer for PDT
Synthesis on Phthalocyanines-based Bifunctional Agents of Contrast Agent for MRI and Photosensitizer for PDT
Contrast agent is playing an increasingly important role in magnetic resonance imaging (MRI), which is recently highly regarded as a new scatheless modality with high resolution and good flexibility in clinical diagnose. Meanwhile, a novel cancer treatment with less poisonous side-effect called photodynamic therapy (PDT) is developed recently, which destroys cancer tissue selectively to avoid injuring surrounding cells, and of which the key problem is to select an appropriate Ball Neodymium Magnets photosensitizer. Hence, it will greatly promote the diagnosis-treat union of MRI and PDT if a new family of bi-functional agents is found which combines the effect of contrast agent in MRI and that of photosensitizer in PDT, and will bring great improvement to the cancer diagnosis and treatment.Phthalocyanine has gradually displayed formidable superiority in photodynamic therapy due to its favorable photophysical efficiency and less side effect.
This paper briefly introduces the synthetic methods of phthalocyanine as photosensitizer applied in PDT and the research progress on phthalocyanine, and also reviews the recent progress of research on bi-functional agents of MRI-PDT.In order to find new products as bi-functional agents of MRI-PDT with good water-solubility, high relaxation potency and ability of liver selection, two series of compound of phthalocyanine have been synthesized in tests. One is the company with carboxyl group saturated alkyl amino metal phthalocyanine (MPc-N(CH2CH2COOH)2), the other is the DTPA monoamides metal phthalocyanine (MPc-NHDTPA), which has similar structure but some different properties when obtained by two different approaches. Next, the Gd(III) complexes is obtained by the reaction of the two kinds of phthalocyanines with GdCl3?6H2O. The phthalocyanines were characterized with FT-IR and 1H NMR, while the complexes were confirmed by FT-IR. Then, Ball Neodymium Magnets Some phthalocyanines and Gd (III) complexes were tested with UV-visible light and the phenomenon of fluorescence is observed.
Finally, the proton longitudinal relaxivity of several kinds of the complexes were tested.It is revealed from the experiment that the http://www.chinamagnets.biz/ water-solubility of the second kind of phthalocyanine is better than that of the first kind of phthalocyanine, though the water-solubility and the difficulty in preparation of the second one are subjected to the center metallic ion. Among all the phthalocyanine, Zn-Pc-NHDTPA and Al-Pc-NHDTPA possess excellent water-solubility. But all the Gd (III) complexes can dissolve in water. Furthermore, the test results of the proton longitudinal relaxivity show that the R1 of Cu-Pc-N(CH2CH2COOH)2?Gd(Ⅲ)?H2O and Co-Pc-N(CH2CH2COOH)2?Gd(Ⅲ)?H2O Ball Neodymium Magnets are respectively more than 81.1% and 149.3% higher than that of Gd-DTPA, which may indicates that the Gd(III) complexes is hopefully expected to be the ideal model of the bi-functional agent of MRI-PDT.
Contrast agent is playing an increasingly important role in magnetic resonance imaging (MRI), which is recently highly regarded as a new scatheless modality with high resolution and good flexibility in clinical diagnose. Meanwhile, a novel cancer treatment with less poisonous side-effect called photodynamic therapy (PDT) is developed recently, which destroys cancer tissue selectively to avoid injuring surrounding cells, and of which the key problem is to select an appropriate Ball Neodymium Magnets photosensitizer. Hence, it will greatly promote the diagnosis-treat union of MRI and PDT if a new family of bi-functional agents is found which combines the effect of contrast agent in MRI and that of photosensitizer in PDT, and will bring great improvement to the cancer diagnosis and treatment.Phthalocyanine has gradually displayed formidable superiority in photodynamic therapy due to its favorable photophysical efficiency and less side effect.
This paper briefly introduces the synthetic methods of phthalocyanine as photosensitizer applied in PDT and the research progress on phthalocyanine, and also reviews the recent progress of research on bi-functional agents of MRI-PDT.In order to find new products as bi-functional agents of MRI-PDT with good water-solubility, high relaxation potency and ability of liver selection, two series of compound of phthalocyanine have been synthesized in tests. One is the company with carboxyl group saturated alkyl amino metal phthalocyanine (MPc-N(CH2CH2COOH)2), the other is the DTPA monoamides metal phthalocyanine (MPc-NHDTPA), which has similar structure but some different properties when obtained by two different approaches. Next, the Gd(III) complexes is obtained by the reaction of the two kinds of phthalocyanines with GdCl3?6H2O. The phthalocyanines were characterized with FT-IR and 1H NMR, while the complexes were confirmed by FT-IR. Then, Ball Neodymium Magnets Some phthalocyanines and Gd (III) complexes were tested with UV-visible light and the phenomenon of fluorescence is observed.
Finally, the proton longitudinal relaxivity of several kinds of the complexes were tested.It is revealed from the experiment that the http://www.chinamagnets.biz/ water-solubility of the second kind of phthalocyanine is better than that of the first kind of phthalocyanine, though the water-solubility and the difficulty in preparation of the second one are subjected to the center metallic ion. Among all the phthalocyanine, Zn-Pc-NHDTPA and Al-Pc-NHDTPA possess excellent water-solubility. But all the Gd (III) complexes can dissolve in water. Furthermore, the test results of the proton longitudinal relaxivity show that the R1 of Cu-Pc-N(CH2CH2COOH)2?Gd(Ⅲ)?H2O and Co-Pc-N(CH2CH2COOH)2?Gd(Ⅲ)?H2O Ball Neodymium Magnets are respectively more than 81.1% and 149.3% higher than that of Gd-DTPA, which may indicates that the Gd(III) complexes is hopefully expected to be the ideal model of the bi-functional agent of MRI-PDT.
2012年3月16日星期五
纳米WC-8(Fe/CoNi)RE硬质合金研究
题名:纳米WC-8(Fe/CoNi)RE硬质合金研究
作者:陈庚
学位授予单位:西华大学
关键词:铁镍基硬质合金;;稀土;;纳米材料;;高能球磨
摘要:
硬质合金具有很高的硬度、熔点、耐磨性和弹性模数,特别是在较高的温度下具有较高的硬度。在所有的硬质合金中,钨钴类硬质合金,即WC—Co硬质合金具有优异的物理、机械性能,较高的抗弯强度及韧性,良好的导热性,Neodymium Magnets在现代耐磨材料、耐高温及腐蚀材料方面起着很重要的作用,广泛地应用于冶金、机械等部门中。但我国的Co资源长期短缺,产量难以满足需求,因此寻求Co的代用品已经迫在眉睫。本课题尝试用性质和结构与Co相似的廉价的Fe、Ni联合运用来部分取代Co。
试验采用高能球磨法制备了WC-8(Fe、Co、Ni)RE合金,着重研究了WC-8(Fe/Co/Ni)RE合金的力学性能和显微组织。将铁镍代钴硬质合金和传统的硬质http://www.999magnet.com/合金性能进行了比较,研究结果表明:以铁、镍、钴做粘结相的硬质合金,其烧结温度明显高于YG类硬质合金,只有当烧结温度超过1430℃时,新型硬质合金才能达到液相烧结,获得较好的致密度;WC-8(Fe、Ni、Co)RE在粘结相之比为65:20:15以及60:20:20时硬度达到90.6HRA左右,烧结制品几乎实现了全致密,其性能超过了传统YG8硬质合金;在试验中添加占粘Neodymium Magnets结相质量1.0%的稀土能够明显抑制WC晶粒的长大,并且提高合金的性能。虽然铁镍代钴硬质合金在提高硬质合金的性能上还有上升空间,但由于其较高的烧结温度,注定铁镍代钴硬质合金中WC晶粒的长大程度要更大一些,性能也不如YG类合金。
学位年度:2009
作者:陈庚
学位授予单位:西华大学
关键词:铁镍基硬质合金;;稀土;;纳米材料;;高能球磨
摘要:
硬质合金具有很高的硬度、熔点、耐磨性和弹性模数,特别是在较高的温度下具有较高的硬度。在所有的硬质合金中,钨钴类硬质合金,即WC—Co硬质合金具有优异的物理、机械性能,较高的抗弯强度及韧性,良好的导热性,Neodymium Magnets在现代耐磨材料、耐高温及腐蚀材料方面起着很重要的作用,广泛地应用于冶金、机械等部门中。但我国的Co资源长期短缺,产量难以满足需求,因此寻求Co的代用品已经迫在眉睫。本课题尝试用性质和结构与Co相似的廉价的Fe、Ni联合运用来部分取代Co。
试验采用高能球磨法制备了WC-8(Fe、Co、Ni)RE合金,着重研究了WC-8(Fe/Co/Ni)RE合金的力学性能和显微组织。将铁镍代钴硬质合金和传统的硬质http://www.999magnet.com/合金性能进行了比较,研究结果表明:以铁、镍、钴做粘结相的硬质合金,其烧结温度明显高于YG类硬质合金,只有当烧结温度超过1430℃时,新型硬质合金才能达到液相烧结,获得较好的致密度;WC-8(Fe、Ni、Co)RE在粘结相之比为65:20:15以及60:20:20时硬度达到90.6HRA左右,烧结制品几乎实现了全致密,其性能超过了传统YG8硬质合金;在试验中添加占粘Neodymium Magnets结相质量1.0%的稀土能够明显抑制WC晶粒的长大,并且提高合金的性能。虽然铁镍代钴硬质合金在提高硬质合金的性能上还有上升空间,但由于其较高的烧结温度,注定铁镍代钴硬质合金中WC晶粒的长大程度要更大一些,性能也不如YG类合金。
学位年度:2009
贵州水银洞金矿床地质特征及成因研究
题名:贵州水银洞金矿床地质特征及成因研究
作者:宋发治
学位授予单位:成都理工大学
关键词:金矿床;;地质特征;;成因;;水银洞;;贵州
摘要:
贵州水银洞金矿床是一个比较典型的大型卡林型隐伏金矿床。行政区划属于贵州省黔西南地区贞丰县小屯乡。大地构造位置处于扬子准地台西南缘与华南褶皱系两个Ⅰ级构造单元的交汇部位,属于华南褶皱系右江褶皱带。区Magnetic lifter域上地处北东向弥勒～师宗深断裂、北西向紫云～垭都深断裂和近东西向开远～平塘深断裂围成的“三角形”夹块,即滇黔桂“金三角”地带。构造受前期深大断裂的影响和制约,构造线主要呈东西向展布。不同期次、不同方向的构造形迹叠加复合,构造变形的组合和发育特点受岩相、岩性制约,在空间上有明显的差异。矿体产出主要受灰家堡背斜及附近断裂控制。矿区内岩浆岩不发育,为少量的偏碱性超基性岩和峨嵋山玄武岩。矿区内出露及钻探地层有:二叠系中统茅口组,二叠系上统龙潭组、长兴组、大隆组,三叠系下统夜郎组、永宁镇组第一段。
水银洞金矿床的赋矿层位有长兴组、龙潭组和构造蚀变体(位于茅口组和龙潭组之间的不整合界面)。矿体以受岩性控制的层状矿体为主、断裂型矿体为辅,以及少量的似层状矿体。矿石的岩石类型有:生物灰岩、粉砂岩、断层角砾岩、泥岩等。矿石中矿石矿物有:黄铁矿、毒砂、赤铁矿、辉锑矿(偶见)、辰砂(偶见)、雄黄(偶见)。Magnetic lifter脉石矿物有:石英、白云石、方解石、水云母、绢云母、高岭石、萤石、海绿石、沸石、有机炭、变质沥青。黄铁矿是金的主要载体,含金黄铁矿粒度主要在0.0005mm～0.05mm即0.5μm～50μm之间,肉眼难以见及,显微镜下呈莓状、球状、皮壳状、环带状等。Au主要呈超显微状态存在。毒砂含量不高,不超过1%,但往往与高品位矿石关系密切。粘土矿物也有一定含金性。矿石中金的品位变化较大,为1.06～48.40×10-6,平均11.72×10-6,变化系数102.03%。Au与As、Sb的相关性较好。碳酸盐岩型矿石品位较高,平均值为21.82×10-6,含量也较稳定,变化系数为59.27%。泥岩型矿石品位较低,平均值为6.73×10-6,变化也较大,变化系数为113.28%。矿石的有用组分Ag、Sb、Cu、Zn、Pb等有益元素不具综合利用价值。有毒有害元素如Tl、Hg等含量很低,不会造成环境问题。As平均含量0.40%,需采用高温预氧化工艺选矿。常量元素分析,矿石中具有较高的硅、镁、三价铁、硫等元素含量。砂岩化学成分的构造背景分析表明,水银洞金矿床砂岩的构造环境可能为活动大陆边缘。矿石中具有较高的Ag、Mn、In等元素,而元素Li、Be、Sc、V、Cr、Co、Ni、Cu、Zn、Ga、Rb、Sr、Y、Cd、Cs、Ba则含量较Magnetic lifter低。Au与主要成矿元素Cu、Zn、As、Sb、Tl、Bi、Sn均呈负相关,线性相关度均不高,相对而言,与As、Sb、Tl关系较为密切。矿石中的稀土总量、轻稀土含量、重稀土含量和轻重稀土比值均较低,灰岩矿石比砂岩矿石低;Eu负异常较弱,Ce负异常较明显。根据矿床构http://www.999magnet.com/造、围岩蚀变、矿石结构构造和矿物共生组合及其相互关系等,可将水银洞金矿成矿作用划分为两个成矿期:沉积成岩期和构造-热液期。构造热液期划分为三个阶段:石英-白云石-黄铁矿阶段、自然金-黄铁矿-毒砂-石英阶段、雄黄-辰砂-石英-方解石阶段。
二叠纪中晚期的海相盆地边缘淡化区沉积,为水银洞金矿床准备了岩性条件,即容矿岩层(生物屑灰岩或粉砂岩)和有利的封闭岩层(粘土岩)。印支晚期～燕山早期的构造运动,伴随着深大断裂和岩浆活动,为深部成矿物质提供了来源和通道。古地温的高异常,为成矿热液提供了热力和热动力条件。矿石黄铁矿Pb同位素组成分析,成矿物质可能主要来源于造山带,以幔源为主,并有上地壳物质混入。成矿流体显示中低温热液特Magnetic lifter点;包裹体氢氧同位素显示,流体可能主要源于大气降水成因的地下热水。热液相对富集轻稀土元素,由于与深部作用和富含长石的岩区有关,而具有正Eu异常。成矿热液沿深大断裂向上运移,并向两侧有利成矿的岩层渗透,次级断裂和褶皱滑脱面,提供了导矿、容矿构造,让成矿物质得以达到有利的容矿场所富集成矿,形成了沿岩层或断裂或褶皱滑脱面产出的矿体。
学位年度:2009
作者:宋发治
学位授予单位:成都理工大学
关键词:金矿床;;地质特征;;成因;;水银洞;;贵州
摘要:
贵州水银洞金矿床是一个比较典型的大型卡林型隐伏金矿床。行政区划属于贵州省黔西南地区贞丰县小屯乡。大地构造位置处于扬子准地台西南缘与华南褶皱系两个Ⅰ级构造单元的交汇部位,属于华南褶皱系右江褶皱带。区Magnetic lifter域上地处北东向弥勒～师宗深断裂、北西向紫云～垭都深断裂和近东西向开远～平塘深断裂围成的“三角形”夹块,即滇黔桂“金三角”地带。构造受前期深大断裂的影响和制约,构造线主要呈东西向展布。不同期次、不同方向的构造形迹叠加复合,构造变形的组合和发育特点受岩相、岩性制约,在空间上有明显的差异。矿体产出主要受灰家堡背斜及附近断裂控制。矿区内岩浆岩不发育,为少量的偏碱性超基性岩和峨嵋山玄武岩。矿区内出露及钻探地层有:二叠系中统茅口组,二叠系上统龙潭组、长兴组、大隆组,三叠系下统夜郎组、永宁镇组第一段。
水银洞金矿床的赋矿层位有长兴组、龙潭组和构造蚀变体(位于茅口组和龙潭组之间的不整合界面)。矿体以受岩性控制的层状矿体为主、断裂型矿体为辅,以及少量的似层状矿体。矿石的岩石类型有:生物灰岩、粉砂岩、断层角砾岩、泥岩等。矿石中矿石矿物有:黄铁矿、毒砂、赤铁矿、辉锑矿(偶见)、辰砂(偶见)、雄黄(偶见)。Magnetic lifter脉石矿物有:石英、白云石、方解石、水云母、绢云母、高岭石、萤石、海绿石、沸石、有机炭、变质沥青。黄铁矿是金的主要载体,含金黄铁矿粒度主要在0.0005mm～0.05mm即0.5μm～50μm之间,肉眼难以见及,显微镜下呈莓状、球状、皮壳状、环带状等。Au主要呈超显微状态存在。毒砂含量不高,不超过1%,但往往与高品位矿石关系密切。粘土矿物也有一定含金性。矿石中金的品位变化较大,为1.06～48.40×10-6,平均11.72×10-6,变化系数102.03%。Au与As、Sb的相关性较好。碳酸盐岩型矿石品位较高,平均值为21.82×10-6,含量也较稳定,变化系数为59.27%。泥岩型矿石品位较低,平均值为6.73×10-6,变化也较大,变化系数为113.28%。矿石的有用组分Ag、Sb、Cu、Zn、Pb等有益元素不具综合利用价值。有毒有害元素如Tl、Hg等含量很低,不会造成环境问题。As平均含量0.40%,需采用高温预氧化工艺选矿。常量元素分析,矿石中具有较高的硅、镁、三价铁、硫等元素含量。砂岩化学成分的构造背景分析表明,水银洞金矿床砂岩的构造环境可能为活动大陆边缘。矿石中具有较高的Ag、Mn、In等元素,而元素Li、Be、Sc、V、Cr、Co、Ni、Cu、Zn、Ga、Rb、Sr、Y、Cd、Cs、Ba则含量较Magnetic lifter低。Au与主要成矿元素Cu、Zn、As、Sb、Tl、Bi、Sn均呈负相关,线性相关度均不高,相对而言,与As、Sb、Tl关系较为密切。矿石中的稀土总量、轻稀土含量、重稀土含量和轻重稀土比值均较低,灰岩矿石比砂岩矿石低;Eu负异常较弱,Ce负异常较明显。根据矿床构http://www.999magnet.com/造、围岩蚀变、矿石结构构造和矿物共生组合及其相互关系等,可将水银洞金矿成矿作用划分为两个成矿期:沉积成岩期和构造-热液期。构造热液期划分为三个阶段:石英-白云石-黄铁矿阶段、自然金-黄铁矿-毒砂-石英阶段、雄黄-辰砂-石英-方解石阶段。
二叠纪中晚期的海相盆地边缘淡化区沉积,为水银洞金矿床准备了岩性条件,即容矿岩层(生物屑灰岩或粉砂岩)和有利的封闭岩层(粘土岩)。印支晚期～燕山早期的构造运动,伴随着深大断裂和岩浆活动,为深部成矿物质提供了来源和通道。古地温的高异常,为成矿热液提供了热力和热动力条件。矿石黄铁矿Pb同位素组成分析,成矿物质可能主要来源于造山带,以幔源为主,并有上地壳物质混入。成矿流体显示中低温热液特Magnetic lifter点;包裹体氢氧同位素显示,流体可能主要源于大气降水成因的地下热水。热液相对富集轻稀土元素,由于与深部作用和富含长石的岩区有关,而具有正Eu异常。成矿热液沿深大断裂向上运移,并向两侧有利成矿的岩层渗透,次级断裂和褶皱滑脱面,提供了导矿、容矿构造,让成矿物质得以达到有利的容矿场所富集成矿,形成了沿岩层或断裂或褶皱滑脱面产出的矿体。
学位年度:2009
2012年3月11日星期日
室温磁致冷材料MnFePGe的SPS制备技术与中子衍射研究
题名:室温磁致冷材料MnFePGe的SPS制备技术与中子衍射研究
作者:刘立江
学位授予单位:北京工业大学
关键词:室温磁致冷材料;;放电等离子烧结;;中子衍射;;磁热效应
摘要:
磁致冷技术是一种高新致冷技术与方法,近年来一直受到国内外的关注。磁致冷与传统压缩致冷相比具有效率高、污染少、结构紧凑、体积小等特点。如能实现室温磁致冷,将会产生巨大的社会效益与经济效益。目前已有许多科研工作者对室温磁致冷材料进行深入的研究,已发现稀土及其合金、稀土-过渡金属neodymium rare earth magnets化合物、过渡金属及其化合物、钙钛矿氧化合物等材料可以应用于室温致冷工程中。
对于磁性致冷材料Mn_(1.1)Fe_(0.9)P_(1-x)Ge_x,其等温磁性转变为一次相变,吸放热量大,且其居里温度随着Mn、Fe及P、Ge比例的变化而变化,能够实现对其温度的控制,从而应用于室温致冷。同时Mn_(1.1)Fe_(0.9)P_(1-x)Ge_x具有原料成本低、无毒无害等诸多优点,具有良好的应用前景。然而这种材料目前多通过长达上百小时的球磨、扩散烧结和退火处理的方法制备,从而严重的影响了材料的实用化发展。而且迄今为止,国内外对MnFePGe系磁致冷材料的研究主要集中在材料制备和性能分析方面,而对材料磁相变过程中晶体结构的变化与性能的关联尚缺乏系统深入的研究和报道,而这是目前制约MnFeneodymium rare earth magnetsPGe系磁致冷材料性能提高的关键所在。据此,本论文研究了采用短时、高效的放电等离子烧结技术(SPS)合成Mn_(1.1)Fe_(0.9)P_(1-x)Ge_x化合物的新方法,并利用中子衍射等手段对其性能与结构的关系进行了研究。
首先,采用机械合金化和放电等离子烧结的方法,合成了成分为Mn1.1Fe0.9P0.8Ge0.2的合金。系统研究了球磨和SPS烧结工艺对合金的相组成及晶体结构的影响,通过优化工艺获得了具有良好单相性的Mn1.1Fe0.9P0.8Ge0.2合金。在此基础上,采用相同的技术路线合成了成分为Mn_(1.1)Fe_(0.9)P_(0.76)Ge_(0.24)的合金样品,制备出的样品具有良好的单相性,但还是含有一定量的MnO等杂质,对制备工艺进一步优化以减少杂质的存在对材料性能的影响。Mn1.1Fe0.9P0.8Ge0.2和Mn_(1.1)Fe_(0.9)P_(0.76)Ge_(0.24)的居里温度分别为251K和279K,说明材料的居里温度随着Ge含量的增加而升高。通过测量不同条件下Mn_(1.1)Fe_(0.9)P_(0.76)Ge_(0.24)样品的磁化曲线,得到了其最大磁熵变为-50J/kg·K左右,这一性能高于目前国内外相关文献报道。
采用中子衍射对Mn_(1.1)Fe_(0.9)P_(0.76)Ge_(0.24)结构和磁性方面进行了深入的研究。研究表明,外界温度和外加磁场变化都会诱发材料顺磁相与铁磁相之间的转变。随着温度的降低,材料中的顺磁相逐渐转变为铁磁相,当温neodymium rare earth magnets度下降到一定程度的时候,材料的相转变变的非常缓慢;同样,随着外加磁场的增加,材料中的顺磁相逐渐转变为铁磁相,当磁场增加到一定程度时,材料的相转变也会变得非常困难。进一步研究表明无论是在外界温度变化条件下还是在外加磁场条件下,顺磁相的晶粒粒径越小,材料的相变就越困难,这说明材料的相转变和晶粒的大小有一定的关系。最后根据中子衍射研究发现,随着材料热滞后的降低,MnFePGe磁化所需的外加磁场强度将减小,若能将材料http://www.chinamagnets.biz/的热滞后降低到0,则材料磁化80%时所需的外加磁场强度只有1.5特斯拉,在这种情况下,普通的永磁磁场就能满足Mn_(1.1)Fe_(0.9)P_(0.76)Ge_(0.24)材料的转变,而不再需要昂贵的超导磁场,从而使MnFePGe材料的应用变的更加现实。
学位年度:2009
作者:刘立江
学位授予单位:北京工业大学
关键词:室温磁致冷材料;;放电等离子烧结;;中子衍射;;磁热效应
摘要:
磁致冷技术是一种高新致冷技术与方法,近年来一直受到国内外的关注。磁致冷与传统压缩致冷相比具有效率高、污染少、结构紧凑、体积小等特点。如能实现室温磁致冷,将会产生巨大的社会效益与经济效益。目前已有许多科研工作者对室温磁致冷材料进行深入的研究,已发现稀土及其合金、稀土-过渡金属neodymium rare earth magnets化合物、过渡金属及其化合物、钙钛矿氧化合物等材料可以应用于室温致冷工程中。
对于磁性致冷材料Mn_(1.1)Fe_(0.9)P_(1-x)Ge_x,其等温磁性转变为一次相变,吸放热量大,且其居里温度随着Mn、Fe及P、Ge比例的变化而变化,能够实现对其温度的控制,从而应用于室温致冷。同时Mn_(1.1)Fe_(0.9)P_(1-x)Ge_x具有原料成本低、无毒无害等诸多优点,具有良好的应用前景。然而这种材料目前多通过长达上百小时的球磨、扩散烧结和退火处理的方法制备,从而严重的影响了材料的实用化发展。而且迄今为止,国内外对MnFePGe系磁致冷材料的研究主要集中在材料制备和性能分析方面,而对材料磁相变过程中晶体结构的变化与性能的关联尚缺乏系统深入的研究和报道,而这是目前制约MnFeneodymium rare earth magnetsPGe系磁致冷材料性能提高的关键所在。据此,本论文研究了采用短时、高效的放电等离子烧结技术(SPS)合成Mn_(1.1)Fe_(0.9)P_(1-x)Ge_x化合物的新方法,并利用中子衍射等手段对其性能与结构的关系进行了研究。
首先,采用机械合金化和放电等离子烧结的方法,合成了成分为Mn1.1Fe0.9P0.8Ge0.2的合金。系统研究了球磨和SPS烧结工艺对合金的相组成及晶体结构的影响,通过优化工艺获得了具有良好单相性的Mn1.1Fe0.9P0.8Ge0.2合金。在此基础上,采用相同的技术路线合成了成分为Mn_(1.1)Fe_(0.9)P_(0.76)Ge_(0.24)的合金样品,制备出的样品具有良好的单相性,但还是含有一定量的MnO等杂质,对制备工艺进一步优化以减少杂质的存在对材料性能的影响。Mn1.1Fe0.9P0.8Ge0.2和Mn_(1.1)Fe_(0.9)P_(0.76)Ge_(0.24)的居里温度分别为251K和279K,说明材料的居里温度随着Ge含量的增加而升高。通过测量不同条件下Mn_(1.1)Fe_(0.9)P_(0.76)Ge_(0.24)样品的磁化曲线,得到了其最大磁熵变为-50J/kg·K左右,这一性能高于目前国内外相关文献报道。
采用中子衍射对Mn_(1.1)Fe_(0.9)P_(0.76)Ge_(0.24)结构和磁性方面进行了深入的研究。研究表明,外界温度和外加磁场变化都会诱发材料顺磁相与铁磁相之间的转变。随着温度的降低,材料中的顺磁相逐渐转变为铁磁相,当温neodymium rare earth magnets度下降到一定程度的时候,材料的相转变变的非常缓慢;同样,随着外加磁场的增加,材料中的顺磁相逐渐转变为铁磁相,当磁场增加到一定程度时,材料的相转变也会变得非常困难。进一步研究表明无论是在外界温度变化条件下还是在外加磁场条件下,顺磁相的晶粒粒径越小,材料的相变就越困难,这说明材料的相转变和晶粒的大小有一定的关系。最后根据中子衍射研究发现,随着材料热滞后的降低,MnFePGe磁化所需的外加磁场强度将减小,若能将材料http://www.chinamagnets.biz/的热滞后降低到0,则材料磁化80%时所需的外加磁场强度只有1.5特斯拉,在这种情况下,普通的永磁磁场就能满足Mn_(1.1)Fe_(0.9)P_(0.76)Ge_(0.24)材料的转变,而不再需要昂贵的超导磁场,从而使MnFePGe材料的应用变的更加现实。
学位年度:2009
紫外上转换增强与颗粒尺寸关系的研究
题名:紫外上转换增强与颗粒尺寸关系的研究
作者:丁福恒
学位授予单位:吉林大学
关键词:稀土掺杂;;紫外增强;;上转换;;尺寸
摘要:
近年来,由于高密度光存储、海底光通信、全色显示和医疗等领域的迫切需要,短波长全固态激光器成为国际上研究的热点。稀土离子掺杂上转换技术,作为实现短波长全固态激光器的一个途径,备受人们的关注。而紫色和紫外上转换激光器正是上转换激光研究者们追求的目标。因此,探索新型高效的紫外上转换发射材料迫在Cube neodymium magnet眉捷,稀土掺杂紫外上转换发射已经成为引人注目的研究课题。和传统的上转换材料相比,纳米尺寸材料的某些性质显示出明显的区别。许多研究表明颗粒变小会增加晶体的荧光效率。但也有许多研究表明颗粒纳米化会降低荧光效率,关于这方面的研究尚无定论。本论文围绕这一问题开展工作,具体内容如下:
(1)利用溶胶凝胶法制备了Yb~(3+),Tm~(3+)共掺杂的CaF_2:Yb~(3+)/Tm~(3+)薄膜。我们对其上转换发射谱进行测量,观察到了明显的紫外上转换增强现象。为了研究颗粒尺寸与紫外上转换增强之间的关系,我们比较了块状体材料Cube neodymium magnet与粉末材料的上转换发光性能。结果表明,从体材料变化至纳米尺寸材料时,紫外上转换发光效率增大。
(2)用水热法合成了不同尺寸的Yb~(3+),Tm~(3+)共掺杂的CaF_2:Yb~(3+)/Tm~(3+)纳米晶样品。我们对其上转换发射谱进行测量,并对其紫外上转换发光效率进行了分析。数据分析结果表明:材料颗粒尺寸在纳米http://www.chinamagnets.biz/尺寸范围时,并非颗粒尺寸越小,紫外上转换增强越好。在某一特定尺寸,紫外上转换发光效率最好,紫外上转换增强现象最明显。
学位年度:2009
作者:丁福恒
学位授予单位:吉林大学
关键词:稀土掺杂;;紫外增强;;上转换;;尺寸
摘要:
近年来,由于高密度光存储、海底光通信、全色显示和医疗等领域的迫切需要,短波长全固态激光器成为国际上研究的热点。稀土离子掺杂上转换技术,作为实现短波长全固态激光器的一个途径,备受人们的关注。而紫色和紫外上转换激光器正是上转换激光研究者们追求的目标。因此,探索新型高效的紫外上转换发射材料迫在Cube neodymium magnet眉捷,稀土掺杂紫外上转换发射已经成为引人注目的研究课题。和传统的上转换材料相比,纳米尺寸材料的某些性质显示出明显的区别。许多研究表明颗粒变小会增加晶体的荧光效率。但也有许多研究表明颗粒纳米化会降低荧光效率,关于这方面的研究尚无定论。本论文围绕这一问题开展工作,具体内容如下:
(1)利用溶胶凝胶法制备了Yb~(3+),Tm~(3+)共掺杂的CaF_2:Yb~(3+)/Tm~(3+)薄膜。我们对其上转换发射谱进行测量,观察到了明显的紫外上转换增强现象。为了研究颗粒尺寸与紫外上转换增强之间的关系,我们比较了块状体材料Cube neodymium magnet与粉末材料的上转换发光性能。结果表明,从体材料变化至纳米尺寸材料时,紫外上转换发光效率增大。
(2)用水热法合成了不同尺寸的Yb~(3+),Tm~(3+)共掺杂的CaF_2:Yb~(3+)/Tm~(3+)纳米晶样品。我们对其上转换发射谱进行测量,并对其紫外上转换发光效率进行了分析。数据分析结果表明:材料颗粒尺寸在纳米http://www.chinamagnets.biz/尺寸范围时,并非颗粒尺寸越小,紫外上转换增强越好。在某一特定尺寸,紫外上转换发光效率最好,紫外上转换增强现象最明显。
学位年度:2009
快淬PrCo_5稀土永磁体的结构和磁性能研究
题名:快淬PrCo_5稀土永磁体的结构和磁性能研究
作者:李绍芳
学位授予单位:吉林大学
关键词:永磁材料;;磁性能;;磁各向异性;;掺杂;;磁能积
摘要:
稀土永磁体PrCo_5具有较高的饱和磁化强度、理论磁能积以及较高的居里温度,但由于其在制备过程中容易生成杂相及其它因素使得PrCo_5在生产中并没有得到实际应用。本文目的在于研究PrCo_5永磁体条带样品具Block neodymium magnet有的磁各向异性规律以及Fe替代Co、C掺杂对磁性能的影响。
把高纯金属单质按一定的比例成分放在电弧炉里熔炼,制成铸锭,再把打碎后的铸锭放在石英管里熔化,通过甩带制备出条带样品。用X射线衍射图谱测定样品的成相,用振动样品磁强计(VSM)测量磁滞回线得出样品矫顽力和磁矩数据。
对PrCo_(5.4)、PrCo_(5.0)和PrCo_(4.6)三个成Block neodymium magnet分的条带样品进行磁性能测试,发现它们具有磁各向异性。通过分析样品XRD图谱可知这是晶体易轴在条带内有序排列的结果。磁矩和矫顽力的大小随易轴在条带里方向的变化而变化,总体来说在易轴方向测量,所得磁矩比较大,矫顽力比较小,在非易轴方向,结果与之相反。增加稀土的含量,发现只有较高带速下的样品才具有较高的矫顽力。
通过对PrCo_(4.9)Fe_(0.5)、PrCo_(4.4)Fe(1.0)和PrCo_(3.9)Fe1.5三个http://www.chinamagnets.biz/成分条带样品的研究发现,Fe替代Co后磁矩上升,矫顽力下降,替代量较大时出现明显的杂相。
通过对PrCo_(5.4)C_(0.2)、PrCo_(5.4)C_(0.4)和PrCo_(5.4)C_(0.6)三个成分条带样品的研究发现,C的掺杂增大了样品的矫顽力和磁Block neodymium magnet能积,并且C的掺杂存在最佳掺杂量,最大矫顽力为6151Oe。
通过对PrCo_(4.9)Fe_(0.5)C_(0.2)、PrCo_(4.9)Fe_(0.5)C_(0.4)和PrCo_(4.9)Fe_(0.5)C_(0.6)三个成分条带样品的研究发现,在C掺杂的基础上用少量Fe替代Co虽然降低了矫顽力,但提高了剩磁,最终使得磁能积仍有很大的提高,最大磁能积达到7.22MGOe。
学位年度:2009
作者:李绍芳
学位授予单位:吉林大学
关键词:永磁材料;;磁性能;;磁各向异性;;掺杂;;磁能积
摘要:
稀土永磁体PrCo_5具有较高的饱和磁化强度、理论磁能积以及较高的居里温度,但由于其在制备过程中容易生成杂相及其它因素使得PrCo_5在生产中并没有得到实际应用。本文目的在于研究PrCo_5永磁体条带样品具Block neodymium magnet有的磁各向异性规律以及Fe替代Co、C掺杂对磁性能的影响。
把高纯金属单质按一定的比例成分放在电弧炉里熔炼,制成铸锭,再把打碎后的铸锭放在石英管里熔化,通过甩带制备出条带样品。用X射线衍射图谱测定样品的成相,用振动样品磁强计(VSM)测量磁滞回线得出样品矫顽力和磁矩数据。
对PrCo_(5.4)、PrCo_(5.0)和PrCo_(4.6)三个成Block neodymium magnet分的条带样品进行磁性能测试,发现它们具有磁各向异性。通过分析样品XRD图谱可知这是晶体易轴在条带内有序排列的结果。磁矩和矫顽力的大小随易轴在条带里方向的变化而变化,总体来说在易轴方向测量,所得磁矩比较大,矫顽力比较小,在非易轴方向,结果与之相反。增加稀土的含量,发现只有较高带速下的样品才具有较高的矫顽力。
通过对PrCo_(4.9)Fe_(0.5)、PrCo_(4.4)Fe(1.0)和PrCo_(3.9)Fe1.5三个http://www.chinamagnets.biz/成分条带样品的研究发现,Fe替代Co后磁矩上升,矫顽力下降,替代量较大时出现明显的杂相。
通过对PrCo_(5.4)C_(0.2)、PrCo_(5.4)C_(0.4)和PrCo_(5.4)C_(0.6)三个成分条带样品的研究发现,C的掺杂增大了样品的矫顽力和磁Block neodymium magnet能积,并且C的掺杂存在最佳掺杂量,最大矫顽力为6151Oe。
通过对PrCo_(4.9)Fe_(0.5)C_(0.2)、PrCo_(4.9)Fe_(0.5)C_(0.4)和PrCo_(4.9)Fe_(0.5)C_(0.6)三个成分条带样品的研究发现,在C掺杂的基础上用少量Fe替代Co虽然降低了矫顽力,但提高了剩磁,最终使得磁能积仍有很大的提高,最大磁能积达到7.22MGOe。
学位年度:2009
芳酰腙金属配合物的合成、结构及其与DNA作用的初探
题名:芳酰腙金属配合物的合成、结构及其与DNA作用的初探
作者:王刘杰
学位授予单位:西北大学
关键词:芳酰腙;;2,6-吡啶二甲酸;;混配体配合物;;晶体结构;;DNA
摘要:
近年来研究具有生活功能的单配或混配体配合物有较大的理论意义及应用价值,本文合成并表征了芳酰腙类单配或混配体配合物,neodymium magnets并对配合物与DNA作用机理进行了初步探讨。
1.合成:在DMF-醇混合溶剂中,以对二甲胺基苯甲酰腙(C_(16)H_(17)N_3O_2,简写为H_2L~1)与过渡金属Ni、Zn、Cd、Cu、Co、Ag、Mn的盐反应,合成了7种新的配合物,并得到了Ni和Cu配合物的单晶;以N-(2-异丙酸)-邻羟基苯甲酰腙(C_(10)H_(10)N_2O_4,简称为H_3L~2)为配体与稀土硝酸盐反应,合成了两种新稀土配合物,并培养出这两种配合物的单晶;以N-(2-乙酸)-邻羟基苯甲酰腙(C_9H_8N_2O_4,简称H_3L~3)和2,6-二neodymium magnets羧酸吡啶(C_6H_5NO_2,H_2PDA)为配体和稀土盐反应,合成出了10种新稀土混配体配合物。
2.表征:通过元素分析、红外光谱、紫外光谱、荧光光谱、X-射线粉末衍射以及TG-DTG等手段对配合物的组成结构和物理化学性质进行了表征,通过X-射http://www.chinamagnets.biz/线单晶衍射仪测定了它们的晶体结构。
3.性质测试:通过紫外吸收光谱和荧光光neodymium magnets谱对配合物与小牛胸腺DNA相互作用的机理进行了初步探讨。
学位年度:2009
作者:王刘杰
学位授予单位:西北大学
关键词:芳酰腙;;2,6-吡啶二甲酸;;混配体配合物;;晶体结构;;DNA
摘要:
近年来研究具有生活功能的单配或混配体配合物有较大的理论意义及应用价值,本文合成并表征了芳酰腙类单配或混配体配合物,neodymium magnets并对配合物与DNA作用机理进行了初步探讨。
1.合成:在DMF-醇混合溶剂中,以对二甲胺基苯甲酰腙(C_(16)H_(17)N_3O_2,简写为H_2L~1)与过渡金属Ni、Zn、Cd、Cu、Co、Ag、Mn的盐反应,合成了7种新的配合物,并得到了Ni和Cu配合物的单晶;以N-(2-异丙酸)-邻羟基苯甲酰腙(C_(10)H_(10)N_2O_4,简称为H_3L~2)为配体与稀土硝酸盐反应,合成了两种新稀土配合物,并培养出这两种配合物的单晶;以N-(2-乙酸)-邻羟基苯甲酰腙(C_9H_8N_2O_4,简称H_3L~3)和2,6-二neodymium magnets羧酸吡啶(C_6H_5NO_2,H_2PDA)为配体和稀土盐反应,合成出了10种新稀土混配体配合物。
2.表征:通过元素分析、红外光谱、紫外光谱、荧光光谱、X-射线粉末衍射以及TG-DTG等手段对配合物的组成结构和物理化学性质进行了表征,通过X-射http://www.chinamagnets.biz/线单晶衍射仪测定了它们的晶体结构。
3.性质测试:通过紫外吸收光谱和荧光光neodymium magnets谱对配合物与小牛胸腺DNA相互作用的机理进行了初步探讨。
学位年度:2009
正丁醇制取烯烃反应的研究
题名:正丁醇制取烯烃反应的研究
作者:崔飞
学位授予单位:西北大学
关键词:正丁醇;;HZSM-5;;改性;;催化裂解
摘要:
随着石油资源的大量消耗及其价格的节节攀升,发展环境友好的生物基产品已成为转变经济增长方式、保障生态链良性循环、实现经Ball Neodymium Magnets济社会可持续发展的战略需求。
HZSM-5分子筛的孔结构特征赋予其独特的择形催化性能,本论文用HZSM-5以及改性HZSM-5分子筛为催化剂,以正丁醇为原料,对正丁醇制取烯烃的反应进行了研究。
在研究过程中发现硅铝比为50的HZSM-5分子筛在正丁醇制烯烃中的催化性能优于25和38的。当反应温度为300℃时,主要发生正丁醇脱水生成丁烯的反应,生成的丁烯开始裂解生成低碳烯烃的温度在320℃。研究了改性HZSM-5分子筛对正丁醇制烯烃的影响,发现以磷、镁改性后的HZSM-5分子筛为催化剂有利于正丁醇生产丙烯,而钼Ball Neodymium Magnets及稀土元素铈改性后的分子筛由于其低丙烯选择性不适合做此反应催化剂。考察了反应温度和液空时速对反应的影响,随着液空时速的增加,低碳烯烃的选择性有所提高,但是高于1.2h~(-1)就不利于反应;升温抑制了氢转移反应的进行,丁烷的产率下降,同时由于裂解强度的加强,乙烯和甲烷的产率皆上升。丙烯的产率随着温度的升高先升后降,其产率升高的原因是裂解强度的加深和其氢转移反应受到抑制,而下降是因为过http://www.chinamagnets.biz/高的反应温度有利于丙烯通过其聚合物的脱氢环化芳构化而生成芳烃。
为考察正丁烯脱水生成的正丁烯的反应规律,以正丁烯为原料,用HZSM-5及改性HZSM-5分子筛作催化剂进行了研究。结果发现,高Ball Neodymium Magnets硅HZSM-5较弱的酸性可抑制氢转移及芳构化副反应的发生,大大提高丙烯选择性及催化剂稳定性。稀土元素铈改性效果不如钼改性的效果。将钼改性催化剂用于C_4烯烃裂解制低碳烯烃的反应过程中,发现适宜的钼改性可效抑制氢转移及芳构化副反应的发生,提高丙烯选择性,并考察了反应条件对性能较佳的改性催化剂催化性能的影响。
学位年度:2009
作者:崔飞
学位授予单位:西北大学
关键词:正丁醇;;HZSM-5;;改性;;催化裂解
摘要:
随着石油资源的大量消耗及其价格的节节攀升,发展环境友好的生物基产品已成为转变经济增长方式、保障生态链良性循环、实现经Ball Neodymium Magnets济社会可持续发展的战略需求。
HZSM-5分子筛的孔结构特征赋予其独特的择形催化性能,本论文用HZSM-5以及改性HZSM-5分子筛为催化剂,以正丁醇为原料,对正丁醇制取烯烃的反应进行了研究。
在研究过程中发现硅铝比为50的HZSM-5分子筛在正丁醇制烯烃中的催化性能优于25和38的。当反应温度为300℃时,主要发生正丁醇脱水生成丁烯的反应,生成的丁烯开始裂解生成低碳烯烃的温度在320℃。研究了改性HZSM-5分子筛对正丁醇制烯烃的影响,发现以磷、镁改性后的HZSM-5分子筛为催化剂有利于正丁醇生产丙烯,而钼Ball Neodymium Magnets及稀土元素铈改性后的分子筛由于其低丙烯选择性不适合做此反应催化剂。考察了反应温度和液空时速对反应的影响,随着液空时速的增加,低碳烯烃的选择性有所提高,但是高于1.2h~(-1)就不利于反应;升温抑制了氢转移反应的进行,丁烷的产率下降,同时由于裂解强度的加强,乙烯和甲烷的产率皆上升。丙烯的产率随着温度的升高先升后降,其产率升高的原因是裂解强度的加深和其氢转移反应受到抑制,而下降是因为过http://www.chinamagnets.biz/高的反应温度有利于丙烯通过其聚合物的脱氢环化芳构化而生成芳烃。
为考察正丁烯脱水生成的正丁烯的反应规律,以正丁烯为原料,用HZSM-5及改性HZSM-5分子筛作催化剂进行了研究。结果发现,高Ball Neodymium Magnets硅HZSM-5较弱的酸性可抑制氢转移及芳构化副反应的发生,大大提高丙烯选择性及催化剂稳定性。稀土元素铈改性效果不如钼改性的效果。将钼改性催化剂用于C_4烯烃裂解制低碳烯烃的反应过程中,发现适宜的钼改性可效抑制氢转移及芳构化副反应的发生,提高丙烯选择性,并考察了反应条件对性能较佳的改性催化剂催化性能的影响。
学位年度:2009
AZ31B镁合金TIG焊焊接接头组织与性能的研究
题名:AZ31B镁合金TIG焊焊接接头组织与性能的研究
作者:王鹤
学位授予单位:吉林大学
关键词:AZ31B镁合金;;钨极氩弧焊;;焊接接头;;微观组织;;力学性能
摘要:
本文采用钨极氩弧焊(TIG)对AZ31B镁合金进行对接接头焊接,研究了镁合金焊接接头的组织及力学性能,探讨了焊接工艺规范参数和焊丝成分对焊接接头组织和力学性能的影响规律。
Segment neodymium magnet
研究表明,镁合金的焊接接头包括焊缝区、热影响区和母材区,焊缝区晶粒细小,热影响区晶粒较为粗大。AZ31B镁合金母材和焊缝的相结构均为镁固溶体(α-Mg)和金属间化合物(β-Al12Mg17)。焊接接头组织和性能会随着工艺
Segment neodymium magnet
参数(焊接电流和焊接速度)和焊丝中Ce、Al含量的变化而变化。
学位年度:2009
作者:王鹤
学位授予单位:吉林大学
关键词:AZ31B镁合金;;钨极氩弧焊;;焊接接头;;微观组织;;力学性能
摘要:
本文采用钨极氩弧焊(TIG)对AZ31B镁合金进行对接接头焊接,研究了镁合金焊接接头的组织及力学性能,探讨了焊接工艺规范参数和焊丝成分对焊接接头组织和力学性能的影响规律。
Segment neodymium magnet
研究表明,镁合金的焊接接头包括焊缝区、热影响区和母材区,焊缝区晶粒细小,热影响区晶粒较为粗大。AZ31B镁合金母材和焊缝的相结构均为镁固溶体(α-Mg)和金属间化合物(β-Al12Mg17)。焊接接头组织和性能会随着工艺
Segment neodymium magnet
参数(焊接电流和焊接速度)和焊丝中Ce、Al含量的变化而变化。
学位年度:2009
青藏高原东北缘晚中生代玄武岩岩石学地球化学及其成因
题名:青藏高原东北缘晚中生代玄武岩岩石学地球化学及其成因
作者:赵文婷
学位授予单位:中国地质大学（北京）
关键词:西秦岭;;多福屯;;玄武岩;;地球化学;;微量元素
摘要:
西秦岭是青藏高原东北缘的一个重要的构造结,是在中国大陆完成其主体拼合过程中,由特提斯阿尔卑斯—喜马拉雅、太平洋和古亚洲及其后的环西伯利亚弧形构造三大构造动力学体系共同作用下,由构成中国大陆的各主要造山带与地块交接汇聚形成的。作为印度-欧亚大陆碰撞及青藏高原隆升的一种响应,西秦岭地区自中rare earth magnets生代以来火山作用非常强烈。其中,最具代表性的火山作用当属新生代钾霞橄黄长岩和碳酸岩火山作用,以及晚中生代玄武岩的火山作用。通过对多福屯晚中生代火山岩的岩石学、40Ar-39Ar定年和地球化学研究,探讨火山岩的源区性质和判别火山岩的形成环境,为揭示青藏高原东北缘的演化及其深部的响应过程提供信息和依据。
多福屯火山岩呈黑色-黑灰色,具杏仁状构造、气孔构造及致密块状构造,斑状结构,斑晶主要由橄榄石、单斜辉石和斜长石组成,基质结晶程度较差,微晶-隐晶质结构,部分样品可见大量细小的长石微晶,其间为隐晶质或玻璃质。全岩主量元rare earth magnets素成分表明,整体上来讲多福屯火山岩属于一套钠质偏碱性的火山岩系列,Mg#值为42～51。对多福屯火山岩进行全岩40Ar-39Ar同位素定年研究,获得3个玄武岩定年数据:84.4Ma、79.3Ma、98.7Ma,本文认为其形成时代可能为晚中生代。电子探针分析结果表明,主要斑晶矿物单斜辉石都属于透辉石,其化学成分的特征及其变化趋势,似表明新生代火山岩与晚中生代火山岩在岩浆源区方面具有相似性和继承性。全岩REE特征属于轻稀土富集型,δ(Eu)=1.33～2.08。微量元http://www.chinamagnets.biz/素分布总体上表现出不相容元素相对富集的特点,具有明显的Pb亏损。单斜辉石稀土微量元素分析表明,单斜辉石是玄武岩中重要的微量元素赋存矿物相。Sr-Nd-Pb同位素分析结果表明,多福屯火山岩显示陆内火山岩的特征,并呈现Dupal异常。采取Kudo和Weill的斜长石地质温度计估算其成岩温度约为1249～1382℃。结合本文与前人工作,推测青rare earth magnets藏高原东北缘多福屯钠质碱性火山岩的起源成因动力学机制与青藏高原下软流圈物质向东逃逸有关。
学位年度:2009
作者:赵文婷
学位授予单位:中国地质大学（北京）
关键词:西秦岭;;多福屯;;玄武岩;;地球化学;;微量元素
摘要:
西秦岭是青藏高原东北缘的一个重要的构造结,是在中国大陆完成其主体拼合过程中,由特提斯阿尔卑斯—喜马拉雅、太平洋和古亚洲及其后的环西伯利亚弧形构造三大构造动力学体系共同作用下,由构成中国大陆的各主要造山带与地块交接汇聚形成的。作为印度-欧亚大陆碰撞及青藏高原隆升的一种响应,西秦岭地区自中rare earth magnets生代以来火山作用非常强烈。其中,最具代表性的火山作用当属新生代钾霞橄黄长岩和碳酸岩火山作用,以及晚中生代玄武岩的火山作用。通过对多福屯晚中生代火山岩的岩石学、40Ar-39Ar定年和地球化学研究,探讨火山岩的源区性质和判别火山岩的形成环境,为揭示青藏高原东北缘的演化及其深部的响应过程提供信息和依据。
多福屯火山岩呈黑色-黑灰色,具杏仁状构造、气孔构造及致密块状构造,斑状结构,斑晶主要由橄榄石、单斜辉石和斜长石组成,基质结晶程度较差,微晶-隐晶质结构,部分样品可见大量细小的长石微晶,其间为隐晶质或玻璃质。全岩主量元rare earth magnets素成分表明,整体上来讲多福屯火山岩属于一套钠质偏碱性的火山岩系列,Mg#值为42～51。对多福屯火山岩进行全岩40Ar-39Ar同位素定年研究,获得3个玄武岩定年数据:84.4Ma、79.3Ma、98.7Ma,本文认为其形成时代可能为晚中生代。电子探针分析结果表明,主要斑晶矿物单斜辉石都属于透辉石,其化学成分的特征及其变化趋势,似表明新生代火山岩与晚中生代火山岩在岩浆源区方面具有相似性和继承性。全岩REE特征属于轻稀土富集型,δ(Eu)=1.33～2.08。微量元http://www.chinamagnets.biz/素分布总体上表现出不相容元素相对富集的特点,具有明显的Pb亏损。单斜辉石稀土微量元素分析表明,单斜辉石是玄武岩中重要的微量元素赋存矿物相。Sr-Nd-Pb同位素分析结果表明,多福屯火山岩显示陆内火山岩的特征,并呈现Dupal异常。采取Kudo和Weill的斜长石地质温度计估算其成岩温度约为1249～1382℃。结合本文与前人工作,推测青rare earth magnets藏高原东北缘多福屯钠质碱性火山岩的起源成因动力学机制与青藏高原下软流圈物质向东逃逸有关。
学位年度:2009
多组分宽带掺铒玻璃光谱性质及比较研究
题名:多组分宽带掺铒玻璃光谱性质及比较研究
作者:盖娜
学位授予单位:宁波大学
关键词:光纤通信;;光谱性质;;碲酸盐玻璃;;铋酸盐玻璃
摘要:
在大容量光纤通信系统中,传统的石英基质掺铒光纤放大器(EDFA)具有高增益、低噪声等许多优良的特性已得到广泛的应用,但是由于其放大带宽只有35nm左右,仅仅覆盖了光纤低损耗窗口中的一小部分带宽,难以完全满足现代密集波分复用(DWDM)系统的要求。因此,研究新型的EDFA基质材料,对实现能同时放大C+L波strong magnets段信号的宽带EDFA非常重要。另外,随着DWDM技术的发展,光纤放大器的小型化要求,需要在单位长度内提高信号增益,这就需要开发高浓度掺杂的玻璃光纤基质。新型宽带掺铒碲酸盐和铋酸盐玻璃具有较宽的荧光有效线宽、较大的峰值发射截面和较好的稀土溶解特性,成为当前研究的热点。
本文对多组分掺铒碲酸盐和铋酸盐玻璃各自进strong magnets行了光谱性质的研究,并在荧光浓度猝灭、荧光俘获及玻璃中OH-根离子对于Er~(3+)离子1.53μm波段荧光的影响等方面作了比较研究,并在此基础了上熔制了碲铋共存的新型宽带玻璃,分析了其光谱性质,为更好的选择掺铒光纤放大器基质玻璃材料提供了理论及实验基础。
论文第一章主要介绍了光纤通信的发展概况以及波分复用系统和掺铒光纤放大器的研究与发展,然后简述了稀土离子掺杂的激光玻璃材料的特点和掺铒宽带玻璃基质材料的研究进展,最后提出了本文的研究内容、研究思strong magnets路以及研究的目的及意义。
论文第二章主要介绍了论文中涉及到的一些理论知识,其中包括Judd-Ofelt理论、McCumber理论、无辐射跃迁机理。
论文第三章主要研究了Er~(3+)掺杂的TeO_2-ZnO-La_2O_3玻璃中引入Ce~(3+)离子对光谱性能的影响。实验发现,Er~(3+)离子在1.53μm处的荧光强度、受激发射截面、荧光半高宽都有所增加,而在975nm激发下的上转换发光strong magnets强度却有所降低。分析了~4I_(11/2)能级和~4I_(13/2能级寿命的变化规律。
论文第四章主要研究了B_2O_3组分对应用于1.53μm波段宽带放大掺Er~(3+):Bi_2O_3-GeO_2- Ga_2O_3-Na2O玻璃光谱性质的影响。研究表明,随着B_2O_3组分的引入,Er~(3+)离子~4I_(11/2)能级和~4I_(13/2)能级寿命都下降,~4I_(13/2)→~4I_(15/2)跃迁的量子效率减少,1.53μm波段荧光发射强度减弱,但进一步展宽了其荧光发射谱,荧光有效线宽增大。
论文第五章主要对Er~(3+)离子掺杂的组分为TeO_2-ZnO-La_2O_3(TZL)碲酸盐玻璃和组分为Bi_2O_3-B_2O_3-GeO_2-Na_2O(BBGN)铋酸盐玻璃的荧光俘获和浓度猝灭效应进行了比较研究。结果发现,在Er_2O_3掺杂摩http://www.chinamagnets.biz/尔数相同的情况下,TZL玻璃比BBGN玻璃具有更为强烈的荧光俘获效应和浓度猝灭效应。
论文第六章主要进行通氧除水处理,研究了玻璃中不同OH-根含量对Er~(3+)离子掺杂的TeO_2-ZnO-La_2O_3(TZL)碲酸盐玻璃和Bi_2O_3-B_2O_3-GeO_2-Na_2O(BBGN)铋酸盐玻璃光谱性质影响的比较。通过红外光谱的测试,计算了OH-根离子的浓度。随着通氧时间的增加,玻璃中OH-根离子浓度下降,导致Er~(3+)离子的~4I_(13/2能级的荧光寿命和荧光强度相应增加。比较了碲酸盐和铋酸盐玻璃中OH-根与Er~(3+)离子之间的相互作用参数KOH-Er,发现在相同的通氧除水时间处理下,碲酸盐玻璃的相互作用参数要小些。
论文第七章主要进行了碲铋组分组合的新型宽带玻璃研制,研究了Er~(3+)/Yb~(3+)共掺TeO_2-Nb_2O_5-Bi_2O_3(TNB)玻璃中Nb_2O_5组分含量的变化对Er~(3+)离子光谱性质的影响。随着Nb_2O_5组分含量的增加,Er~(3+)离子的光学强度参数Ω_t(t=2,4,6)呈现出先增大后减少趋势。在TNB玻璃系统中Er~(3+)离子有较大的FWHM×σe参数值,优于Er~(3+)离子掺杂的硅酸盐和磷酸盐玻璃,且具有较好的热稳定性,因此有可能成为制备宽带掺铒光纤放大器的潜在基质材料。
最后是本文的结论部分,概括了http://www.chinamagnets.biz/全文创新性理论及实验研究结果,同时指出了存在的不足以及需要改进的地方。
学位年度:2009
作者:盖娜
学位授予单位:宁波大学
关键词:光纤通信;;光谱性质;;碲酸盐玻璃;;铋酸盐玻璃
摘要:
在大容量光纤通信系统中,传统的石英基质掺铒光纤放大器(EDFA)具有高增益、低噪声等许多优良的特性已得到广泛的应用,但是由于其放大带宽只有35nm左右,仅仅覆盖了光纤低损耗窗口中的一小部分带宽,难以完全满足现代密集波分复用(DWDM)系统的要求。因此,研究新型的EDFA基质材料,对实现能同时放大C+L波strong magnets段信号的宽带EDFA非常重要。另外,随着DWDM技术的发展,光纤放大器的小型化要求,需要在单位长度内提高信号增益,这就需要开发高浓度掺杂的玻璃光纤基质。新型宽带掺铒碲酸盐和铋酸盐玻璃具有较宽的荧光有效线宽、较大的峰值发射截面和较好的稀土溶解特性,成为当前研究的热点。
本文对多组分掺铒碲酸盐和铋酸盐玻璃各自进strong magnets行了光谱性质的研究,并在荧光浓度猝灭、荧光俘获及玻璃中OH-根离子对于Er~(3+)离子1.53μm波段荧光的影响等方面作了比较研究,并在此基础了上熔制了碲铋共存的新型宽带玻璃,分析了其光谱性质,为更好的选择掺铒光纤放大器基质玻璃材料提供了理论及实验基础。
论文第一章主要介绍了光纤通信的发展概况以及波分复用系统和掺铒光纤放大器的研究与发展,然后简述了稀土离子掺杂的激光玻璃材料的特点和掺铒宽带玻璃基质材料的研究进展,最后提出了本文的研究内容、研究思strong magnets路以及研究的目的及意义。
论文第二章主要介绍了论文中涉及到的一些理论知识,其中包括Judd-Ofelt理论、McCumber理论、无辐射跃迁机理。
论文第三章主要研究了Er~(3+)掺杂的TeO_2-ZnO-La_2O_3玻璃中引入Ce~(3+)离子对光谱性能的影响。实验发现,Er~(3+)离子在1.53μm处的荧光强度、受激发射截面、荧光半高宽都有所增加,而在975nm激发下的上转换发光strong magnets强度却有所降低。分析了~4I_(11/2)能级和~4I_(13/2能级寿命的变化规律。
论文第四章主要研究了B_2O_3组分对应用于1.53μm波段宽带放大掺Er~(3+):Bi_2O_3-GeO_2- Ga_2O_3-Na2O玻璃光谱性质的影响。研究表明,随着B_2O_3组分的引入,Er~(3+)离子~4I_(11/2)能级和~4I_(13/2)能级寿命都下降,~4I_(13/2)→~4I_(15/2)跃迁的量子效率减少,1.53μm波段荧光发射强度减弱,但进一步展宽了其荧光发射谱,荧光有效线宽增大。
论文第五章主要对Er~(3+)离子掺杂的组分为TeO_2-ZnO-La_2O_3(TZL)碲酸盐玻璃和组分为Bi_2O_3-B_2O_3-GeO_2-Na_2O(BBGN)铋酸盐玻璃的荧光俘获和浓度猝灭效应进行了比较研究。结果发现,在Er_2O_3掺杂摩http://www.chinamagnets.biz/尔数相同的情况下,TZL玻璃比BBGN玻璃具有更为强烈的荧光俘获效应和浓度猝灭效应。
论文第六章主要进行通氧除水处理,研究了玻璃中不同OH-根含量对Er~(3+)离子掺杂的TeO_2-ZnO-La_2O_3(TZL)碲酸盐玻璃和Bi_2O_3-B_2O_3-GeO_2-Na_2O(BBGN)铋酸盐玻璃光谱性质影响的比较。通过红外光谱的测试,计算了OH-根离子的浓度。随着通氧时间的增加,玻璃中OH-根离子浓度下降,导致Er~(3+)离子的~4I_(13/2能级的荧光寿命和荧光强度相应增加。比较了碲酸盐和铋酸盐玻璃中OH-根与Er~(3+)离子之间的相互作用参数KOH-Er,发现在相同的通氧除水时间处理下,碲酸盐玻璃的相互作用参数要小些。
论文第七章主要进行了碲铋组分组合的新型宽带玻璃研制,研究了Er~(3+)/Yb~(3+)共掺TeO_2-Nb_2O_5-Bi_2O_3(TNB)玻璃中Nb_2O_5组分含量的变化对Er~(3+)离子光谱性质的影响。随着Nb_2O_5组分含量的增加,Er~(3+)离子的光学强度参数Ω_t(t=2,4,6)呈现出先增大后减少趋势。在TNB玻璃系统中Er~(3+)离子有较大的FWHM×σe参数值,优于Er~(3+)离子掺杂的硅酸盐和磷酸盐玻璃,且具有较好的热稳定性,因此有可能成为制备宽带掺铒光纤放大器的潜在基质材料。
最后是本文的结论部分,概括了http://www.chinamagnets.biz/全文创新性理论及实验研究结果,同时指出了存在的不足以及需要改进的地方。
学位年度:2009
芳杂环类金属有机配合物的合成及性质研究
题名:芳杂环类金属有机配合物的合成及性质研究
作者:张涛
学位授予单位:宁波大学
关键词:希夫碱;;发光;;有机膦;;离子液体;;2-吡啶硼酸酯
摘要:
金属有机化学作为前沿学科发展的重要领域,其在医药、农药、工业等众多领域都有广泛的应用。本文主要研究了芳杂环取代的neodymium rare earth magnets希夫碱及其金属配合物合成、表征及其发光性质;官能团化离子液体的合成及吡啶芳杂环有机中间体的制备:
(I)合成了2-呋喃、3-吡啶、2-(N-甲基咪唑)三种芳杂环5位取代的3-甲氧基水杨醛以及2-吡啶、2-噻吩两种芳杂环3,5位二取代的水杨醛,前三种水杨醛分别通过与邻苯二胺、乙二胺缩合以较高的产率(80 ~ 97 %)制备了五种希夫碱,并进一步与过渡金属离子Zn~(2+) (3d)以较高的产率(88 ~ 97 %)合成了五种单金属配合物,最终,该过渡金属neodymium rare earth magnets配合物与五种稀土离子Nd~(3+), Gd~(3+), Tb~(3+), Er~(3+), Yb~(3+) (4f)合成了多种3d-4f双金属配合物。
通过核磁、红外、质谱表征了这些化合物。测定了目标稀土金属配合物的发光性质,结果表明,这些希夫碱均可激发Nd~(3+), Er~(3+), Yb~(3+)发出稀土离子在近红外区(NIR)的特征荧光,通过测定Gd~(3+)配合物的分子荧光,证明了有机稀土金属配合物的发光机理是通过有机配体吸收紫外能量从激发单重态传递到激发三重态再到稀土离子。
(II)通过1,1’-二(丙醇)-2,2’-联咪唑、1,1’-二(丙基氯)-2,2’-联咪唑中间体合成了三价有机膦1,1’-二(丙基二苯基膦)-2,2’-联咪唑以及五价有机膦1,1’-二(丙基二苯基氧膦)-2,2’-联咪唑和1,1’-二(丙基二苯基硫膦)-2,2’-联咪唑neodymium rare earth magnets三种有机膦化合物,并对三价有机膦化合物进行了烷基化得到了官能团化的离子液体。产物经过了核磁、红外、质谱表征。并对各种中性产物进行了X-ray单晶衍射分析,表明,各种物质在固态均http://www.chinamagnets.biz/采用反式构象,取代基位于联咪唑的两侧;同时合成了顺式构象的金属Pd (II)配合物。
(III)合成了两种重要的有机中间体2-吡啶频哪醇硼酸酯、2-吡啶二甘醇硼酸酯。探讨研究了合成方法,并将离子液体应neodymium rare earth magnets用于2-吡啶频哪醇硼酸酯的合成中,表明此方法是最佳的绿色高效合成方案。产物经过了GC-MS表征。
学位年度:2009
作者:张涛
学位授予单位:宁波大学
关键词:希夫碱;;发光;;有机膦;;离子液体;;2-吡啶硼酸酯
摘要:
金属有机化学作为前沿学科发展的重要领域,其在医药、农药、工业等众多领域都有广泛的应用。本文主要研究了芳杂环取代的neodymium rare earth magnets希夫碱及其金属配合物合成、表征及其发光性质;官能团化离子液体的合成及吡啶芳杂环有机中间体的制备:
(I)合成了2-呋喃、3-吡啶、2-(N-甲基咪唑)三种芳杂环5位取代的3-甲氧基水杨醛以及2-吡啶、2-噻吩两种芳杂环3,5位二取代的水杨醛,前三种水杨醛分别通过与邻苯二胺、乙二胺缩合以较高的产率(80 ~ 97 %)制备了五种希夫碱,并进一步与过渡金属离子Zn~(2+) (3d)以较高的产率(88 ~ 97 %)合成了五种单金属配合物,最终,该过渡金属neodymium rare earth magnets配合物与五种稀土离子Nd~(3+), Gd~(3+), Tb~(3+), Er~(3+), Yb~(3+) (4f)合成了多种3d-4f双金属配合物。
通过核磁、红外、质谱表征了这些化合物。测定了目标稀土金属配合物的发光性质,结果表明,这些希夫碱均可激发Nd~(3+), Er~(3+), Yb~(3+)发出稀土离子在近红外区(NIR)的特征荧光,通过测定Gd~(3+)配合物的分子荧光,证明了有机稀土金属配合物的发光机理是通过有机配体吸收紫外能量从激发单重态传递到激发三重态再到稀土离子。
(II)通过1,1’-二(丙醇)-2,2’-联咪唑、1,1’-二(丙基氯)-2,2’-联咪唑中间体合成了三价有机膦1,1’-二(丙基二苯基膦)-2,2’-联咪唑以及五价有机膦1,1’-二(丙基二苯基氧膦)-2,2’-联咪唑和1,1’-二(丙基二苯基硫膦)-2,2’-联咪唑neodymium rare earth magnets三种有机膦化合物,并对三价有机膦化合物进行了烷基化得到了官能团化的离子液体。产物经过了核磁、红外、质谱表征。并对各种中性产物进行了X-ray单晶衍射分析,表明,各种物质在固态均http://www.chinamagnets.biz/采用反式构象,取代基位于联咪唑的两侧;同时合成了顺式构象的金属Pd (II)配合物。
(III)合成了两种重要的有机中间体2-吡啶频哪醇硼酸酯、2-吡啶二甘醇硼酸酯。探讨研究了合成方法,并将离子液体应neodymium rare earth magnets用于2-吡啶频哪醇硼酸酯的合成中,表明此方法是最佳的绿色高效合成方案。产物经过了GC-MS表征。
学位年度:2009
2012年3月8日星期四
Research on Automatic Non-Magnetic Three-Axis Rotary Table
Research on Automatic Non-Magnetic Three-Axis Rotary Table
Three-axis rotary table is a simulation equipment which can turn in three dimensions. It is used for simulating the movement of a missile,fish torpedo and self-guided aero craft,and testing the navigation system, control system of them. Therefore,it is such a pivotal equipment for testing the performance of a missile,fish torpedo and self-guided aero-craft that playing a momentous part in research and development on these productsThe automatic three-axis rotary table researched on this paper is overall non-magnetic. The distortion of the magnetic field caused by the rotary table is not more than 7nT, when it works in a magnetic field. It can achieve 360-degree continuous rotary or magnet lifter cyclical swing according to the input law and accurately stop in a designated location. The automatic non-magnetic three-axis rotary table is a special equipment for emulating, testing and identifying the performance of the fish torpedo sensor in a uniform magnetic fieldAn in-depth research and analysis has been done on the automatic non-magnetic three-axis rotary table in this paper.First of all, the author http://www.999magnet.com/ pointed out the key points in design of the rotary table, and detailedly analyzed, calculated the non-magnetic requirements of the table by some magnetic theory.
Then, the author summarized some principles for designing a non-magnetic mechanical structure and raised a new non-magnetic long-distance mechanical -hydraulic drive and servo control plan according to the working environment requirements ,precision requirements and the principles,The author also comprehensively presented the overall plan of the automatic three-axis rotary table and its control system, hydraulic system principle. Systematically described the method how to achieve, introduced the mechanical structure of each parts in detailIn the designing process, magnet lifter a series of measures has been taken to limit the table’s magnetism strictly, such as: used non-magnetic material for manufacturing, employed a non-magnetic hydraulic conductive rotary joint and non-magnetic electricity conductive rotary joint, designed a new non-magnetic mechanism hydraulic valve, used a non-magnetic angular displacement grating for measuring.Finally, the author magnet lifter calculated the distortion caused by rotary table in a uniform magnetic field, and computed the stiffness and strength of the octagon frame and U-shaped frame by COSMOS Works and analyzed all precision of the rotary table.
Three-axis rotary table is a simulation equipment which can turn in three dimensions. It is used for simulating the movement of a missile,fish torpedo and self-guided aero craft,and testing the navigation system, control system of them. Therefore,it is such a pivotal equipment for testing the performance of a missile,fish torpedo and self-guided aero-craft that playing a momentous part in research and development on these productsThe automatic three-axis rotary table researched on this paper is overall non-magnetic. The distortion of the magnetic field caused by the rotary table is not more than 7nT, when it works in a magnetic field. It can achieve 360-degree continuous rotary or magnet lifter cyclical swing according to the input law and accurately stop in a designated location. The automatic non-magnetic three-axis rotary table is a special equipment for emulating, testing and identifying the performance of the fish torpedo sensor in a uniform magnetic fieldAn in-depth research and analysis has been done on the automatic non-magnetic three-axis rotary table in this paper.First of all, the author http://www.999magnet.com/ pointed out the key points in design of the rotary table, and detailedly analyzed, calculated the non-magnetic requirements of the table by some magnetic theory.
Then, the author summarized some principles for designing a non-magnetic mechanical structure and raised a new non-magnetic long-distance mechanical -hydraulic drive and servo control plan according to the working environment requirements ,precision requirements and the principles,The author also comprehensively presented the overall plan of the automatic three-axis rotary table and its control system, hydraulic system principle. Systematically described the method how to achieve, introduced the mechanical structure of each parts in detailIn the designing process, magnet lifter a series of measures has been taken to limit the table’s magnetism strictly, such as: used non-magnetic material for manufacturing, employed a non-magnetic hydraulic conductive rotary joint and non-magnetic electricity conductive rotary joint, designed a new non-magnetic mechanism hydraulic valve, used a non-magnetic angular displacement grating for measuring.Finally, the author magnet lifter calculated the distortion caused by rotary table in a uniform magnetic field, and computed the stiffness and strength of the octagon frame and U-shaped frame by COSMOS Works and analyzed all precision of the rotary table.
Research on the DSP-based Driving Technology of the AC Permanent Magnetic Synchronous Linear Motors
Research on the DSP-based Driving Technology of the AC Permanent Magnetic Synchronous Linear Motors
Compared with common servo driving mechanism, linear motors have lots of advantages in fast response and precision, because it could convert electrical energy into linear motion directly. Using linear motor servo driving system is a new development direction of high speed precision machines. At present, researching on linear motors and its servo driving neodymium rare earth magnets technologies has become an academic focus.Firstly, the general structure and basic working principle of Permanent-Magnet Synchronous Linear Motor (PMSLM) are introduced in this paper. According to the operation principles of DSP (Digital Signal Processor) and IPM (Intelligent Power Modules), an overall design scheme for PMSLM is proposed.Because the main point of this http://www.999magnet.com/ paper is about linear motors’driving technology, a printed circuit board including several function modules is designed.
The whole driving system’s security and reliability are enhanced by the protective circuits for the main circuit on the board. Interface circuits for DSP and IPM are designed according to their inner operational principles. Based on AT89C52, display module for linear motor’s parameters is developed and the communication between AT89C52 and DSP is implemented. During the process of experiment and board designing, series of measures are introduced to avoid noise. In order to meet the requirement of PMSLM servo driving system, a multi-output single-chip neodymium rare earth magnets switching power supply is developed using TOP223Y as a pulse width modulation chip. After analyzing the TOP223Y’s operational principle, a high frequency transformer and the whole power supply circuit are designed. In the meantime, this paper also discussed how to reduce ripple voltage.Finally, some experiments are carried out to verify the performance of the developed driving system.The experimental results include velocity and ripple voltage test of auxiliary switching power supply.
Compared with common servo driving mechanism, linear motors have lots of advantages in fast response and precision, because it could convert electrical energy into linear motion directly. Using linear motor servo driving system is a new development direction of high speed precision machines. At present, researching on linear motors and its servo driving neodymium rare earth magnets technologies has become an academic focus.Firstly, the general structure and basic working principle of Permanent-Magnet Synchronous Linear Motor (PMSLM) are introduced in this paper. According to the operation principles of DSP (Digital Signal Processor) and IPM (Intelligent Power Modules), an overall design scheme for PMSLM is proposed.Because the main point of this http://www.999magnet.com/ paper is about linear motors’driving technology, a printed circuit board including several function modules is designed.
The whole driving system’s security and reliability are enhanced by the protective circuits for the main circuit on the board. Interface circuits for DSP and IPM are designed according to their inner operational principles. Based on AT89C52, display module for linear motor’s parameters is developed and the communication between AT89C52 and DSP is implemented. During the process of experiment and board designing, series of measures are introduced to avoid noise. In order to meet the requirement of PMSLM servo driving system, a multi-output single-chip neodymium rare earth magnets switching power supply is developed using TOP223Y as a pulse width modulation chip. After analyzing the TOP223Y’s operational principle, a high frequency transformer and the whole power supply circuit are designed. In the meantime, this paper also discussed how to reduce ripple voltage.Finally, some experiments are carried out to verify the performance of the developed driving system.The experimental results include velocity and ripple voltage test of auxiliary switching power supply.
2012年3月7日星期三
Tungsten Trioxide Gas Sensening Thin Film Prepared by Magnetron Sputtering
Tungsten Trioxide Gas Sensening Thin Film Prepared by Magnetron Sputtering
In industrial production and daily life, gas sensors has been widely used to detect toxic gases, flammable gases, and explosive gases to ensure the security of production and life. Therefore the increasingly highly requirements for gas sensors will promote a highly sensitive, reliable, selective gas sensor development. In many gas-sensing materials, WO3 gas comes to the fore because of its excellent gas-sensitivity and highly stability. Tungsten trioxide is one n-type semiconductor Ball Neodymium Magnets material,when it is exposed to the gas which is to be detected (NOx, H2, CO, NH3, C2H5OH, etc.), oxygen adsorbed from the air as an electron acceptor state is in three tungsten oxide material’s cut-belt, the reaction of gas on the surface caused that the coverage on some parts of the surface changes, which led to a conductivity change. Currently study of WO3 thin film sensor is just in the ascendant, researchers widely used sol-gel method and vacuum evaporation method to make the gas-sensitive tungsten oxide films.Taking into account that sputtering films have highly purity, good adhesion between film and substrate, uniform-sized particle which constitutes the film, easy realization of nanoparticle films, Ball Neodymium Magnets and that the process is easier to control and so on, in this thesis, facing targets direct current magnetron sputtering method is used to prepare WO3 thin films with highly gas-sensing.
Via designing of different experiments, this thesis uses SEM, AFM, XRD and other advanced analytical tools and static gas testing system to analyze the influence of the substrate material, the substrate temperature and sputtering gas ratio, annealing conditions to the microscopic structure, electricity and gas properties of the sample, and found some rules and optimal parameters of some conditions.The sensitivity, operating temperature, selectivity and response time of the superficial modified WO3 thin films have been improved with varying degree. After appending Ti, when the thickness of superficial modified TiO2 layer is 30nm, the microstructure of WO3 thin film has been Ball Neodymium Magnets obviously improved, in the case of operating temperature for 120℃and 15ppm NO2 , the sensitivity achieves 25.2, and WO3 film has the good selectivity and the shorter response time, and is one kind of ideal gas sensor.
In industrial production and daily life, gas sensors has been widely used to detect toxic gases, flammable gases, and explosive gases to ensure the security of production and life. Therefore the increasingly highly requirements for gas sensors will promote a highly sensitive, reliable, selective gas sensor development. In many gas-sensing materials, WO3 gas comes to the fore because of its excellent gas-sensitivity and highly stability. Tungsten trioxide is one n-type semiconductor Ball Neodymium Magnets material,when it is exposed to the gas which is to be detected (NOx, H2, CO, NH3, C2H5OH, etc.), oxygen adsorbed from the air as an electron acceptor state is in three tungsten oxide material’s cut-belt, the reaction of gas on the surface caused that the coverage on some parts of the surface changes, which led to a conductivity change. Currently study of WO3 thin film sensor is just in the ascendant, researchers widely used sol-gel method and vacuum evaporation method to make the gas-sensitive tungsten oxide films.Taking into account that sputtering films have highly purity, good adhesion between film and substrate, uniform-sized particle which constitutes the film, easy realization of nanoparticle films, Ball Neodymium Magnets and that the process is easier to control and so on, in this thesis, facing targets direct current magnetron sputtering method is used to prepare WO3 thin films with highly gas-sensing.
Via designing of different experiments, this thesis uses SEM, AFM, XRD and other advanced analytical tools and static gas testing system to analyze the influence of the substrate material, the substrate temperature and sputtering gas ratio, annealing conditions to the microscopic structure, electricity and gas properties of the sample, and found some rules and optimal parameters of some conditions.The sensitivity, operating temperature, selectivity and response time of the superficial modified WO3 thin films have been improved with varying degree. After appending Ti, when the thickness of superficial modified TiO2 layer is 30nm, the microstructure of WO3 thin film has been Ball Neodymium Magnets obviously improved, in the case of operating temperature for 120℃and 15ppm NO2 , the sensitivity achieves 25.2, and WO3 film has the good selectivity and the shorter response time, and is one kind of ideal gas sensor.
2M219连续波磁控管工作稳定性研究
2M219连续波磁控管工作稳定性研究
With the continuous development of society, the advances of science and technology, microwave ovens have entered every family, and become one of the most commonly used household appliances. The development of microwave ovens leads to that of the magnetron, makes the demand of magnetron continues year by year. It brings not only the opportunities but also the challlenges to magnetron manufacturers. As most of the microwave ovens are in European neodymium magnets developed country, the quality of the microwave is in very strict requirements. What firstly determines the quality of the microwave ovens is magnetron’s quality ,and the stability of the magnetron determine the stability of microwave ovens directly, which is why for many manufacturers magnetron, it is essential to upgrade the magnetron stability within limited cost space.
This paper aims at the stability of the magnetron, basing on the principle of magnetron, connecting with the production process nowadays, analyses the various causes of instability of magnetron, and responses to variety of factors to have a experiment test, to identify the measures to improve and ultimately enhance the stability of existing products. The summary is as followed:1. neodymium magnets Study the causes and mechanism of instability.2. Combined with the existing production process, in theory, advance the program to improve the stability of the magnetron.3. Improve the production process of magnetron and put up enough experiment to confirm the validity http://www.chinamagnets.biz/ of the full improvement.4. Carry out the mass production process after improvement, and to form some technical documents.
With the continuous development of society, the advances of science and technology, microwave ovens have entered every family, and become one of the most commonly used household appliances. The development of microwave ovens leads to that of the magnetron, makes the demand of magnetron continues year by year. It brings not only the opportunities but also the challlenges to magnetron manufacturers. As most of the microwave ovens are in European neodymium magnets developed country, the quality of the microwave is in very strict requirements. What firstly determines the quality of the microwave ovens is magnetron’s quality ,and the stability of the magnetron determine the stability of microwave ovens directly, which is why for many manufacturers magnetron, it is essential to upgrade the magnetron stability within limited cost space.
This paper aims at the stability of the magnetron, basing on the principle of magnetron, connecting with the production process nowadays, analyses the various causes of instability of magnetron, and responses to variety of factors to have a experiment test, to identify the measures to improve and ultimately enhance the stability of existing products. The summary is as followed:1. neodymium magnets Study the causes and mechanism of instability.2. Combined with the existing production process, in theory, advance the program to improve the stability of the magnetron.3. Improve the production process of magnetron and put up enough experiment to confirm the validity http://www.chinamagnets.biz/ of the full improvement.4. Carry out the mass production process after improvement, and to form some technical documents.
2012年3月4日星期日
The Applications of Functional MRI in Patients with Visual Pathway Diseases
The Applications of Functional MRI in Patients with Visual Pathway Diseases
Objective To observe retinotopic representations of health adults using functional magnetic resonance imaging, to investigate the retinotopic representations of patients who have visual pathway diseases and compare the the results of the fMRI imaging and the central visual field examination.Subjects and Methods Subjects: 1.Three health adults aged 24-30(2 male, 1 female), without contraindications of MRI. Visual acuity was 1.0 or corrected to 1.0. 2. Two patients with optic neuritis and four patients with sellar region occupying, including three patients with pituitary magnetic lifter adenoma and one patient with craniopharyngioma. Methods: Visual stimuli: The stimuli subtended a field of view of about 12 degrees, consisted of high contrast, drifting checkerboards. Two types of stimuli were used: the annular ring, either contracting or expanding, was used to map eccentricity and the rotating wedge, either clockwise or counterclockwise, was used to map the polar angle. MRI parameters: GE signa VH/i 3.0T scanner. Functional data: GRE-EPI sequence, 20 slices lying perpendicular to the calcarine sulcus. Anatomical data was obtained using 3D-SPGR sequence to acquire high resolution.
Data analysis: The cortical surface was unfolded and then cut and inflated. Functional data was presented to the inflated surface and subsequently analyzed magnetic lifter by AFNI software.Results The retinotopic representations of health adults were obtained by using the phase-encoded visual stimuli. The Eccentricity coordinate maps showed that foveal representations lay in the occipital poles and the representations appeared further anterior as eccentricity increased. The Polar angle coordinate maps showed that early retinotopically organized areas had a representation of visual field. In 6 patients, 5 had loss of visual acuity, abnormal of VEP and visual field defects. The main patterns of visual field abnormalities were superior temporal defect, temporal hemianopia and central scotoma et al. Less or no visual cortex response was revealed in the patients’ fMRI or the response in injury side was vanished.
The visual cortex response related with the visual field defects can not be induced in fMRI. But the retinotopic representations of the visual cortex did not change.Conclusion Phase-encoded stimuli was validated to be an efficient way to revealretinotopic representations of visual cortex; in patients who have visual pathwaydiseases, the results of fMRI and perimetric evaluation were positively correlated.The functional activations found in the visual cortex were consistent with the resultsof perimetric evaluation. There was a good correlation between fMRI data and theresults of magnetic lifter perimetric evaluation. The fMRI can show the visual field defects underpathological conditions; promising a solid foundation for the future research underpathological conditions.
Objective To observe retinotopic representations of health adults using functional magnetic resonance imaging, to investigate the retinotopic representations of patients who have visual pathway diseases and compare the the results of the fMRI imaging and the central visual field examination.Subjects and Methods Subjects: 1.Three health adults aged 24-30(2 male, 1 female), without contraindications of MRI. Visual acuity was 1.0 or corrected to 1.0. 2. Two patients with optic neuritis and four patients with sellar region occupying, including three patients with pituitary magnetic lifter adenoma and one patient with craniopharyngioma. Methods: Visual stimuli: The stimuli subtended a field of view of about 12 degrees, consisted of high contrast, drifting checkerboards. Two types of stimuli were used: the annular ring, either contracting or expanding, was used to map eccentricity and the rotating wedge, either clockwise or counterclockwise, was used to map the polar angle. MRI parameters: GE signa VH/i 3.0T scanner. Functional data: GRE-EPI sequence, 20 slices lying perpendicular to the calcarine sulcus. Anatomical data was obtained using 3D-SPGR sequence to acquire high resolution.
Data analysis: The cortical surface was unfolded and then cut and inflated. Functional data was presented to the inflated surface and subsequently analyzed magnetic lifter by AFNI software.Results The retinotopic representations of health adults were obtained by using the phase-encoded visual stimuli. The Eccentricity coordinate maps showed that foveal representations lay in the occipital poles and the representations appeared further anterior as eccentricity increased. The Polar angle coordinate maps showed that early retinotopically organized areas had a representation of visual field. In 6 patients, 5 had loss of visual acuity, abnormal of VEP and visual field defects. The main patterns of visual field abnormalities were superior temporal defect, temporal hemianopia and central scotoma et al. Less or no visual cortex response was revealed in the patients’ fMRI or the response in injury side was vanished.
The visual cortex response related with the visual field defects can not be induced in fMRI. But the retinotopic representations of the visual cortex did not change.Conclusion Phase-encoded stimuli was validated to be an efficient way to revealretinotopic representations of visual cortex; in patients who have visual pathwaydiseases, the results of fMRI and perimetric evaluation were positively correlated.The functional activations found in the visual cortex were consistent with the resultsof perimetric evaluation. There was a good correlation between fMRI data and theresults of magnetic lifter perimetric evaluation. The fMRI can show the visual field defects underpathological conditions; promising a solid foundation for the future research underpathological conditions.
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