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线粒体通透性转变孔道与神经系统疾病 被引量:3
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作者 郑春艳 章海燕 《中国新药与临床杂志》 CAS CSCD 北大核心 2008年第6期454-461,共8页
线粒体通透性转变孔道被认为可能主要由位于线粒体外膜的电压依赖性阴离子通道(voltage—dependent anion channel,VDAC)、位于内膜的腺苷酸转移酶(adenine nucleotide translocase,ANT)和位于线粒体基质的亲环素D(cyclophilin-D,CyP—D... 线粒体通透性转变孔道被认为可能主要由位于线粒体外膜的电压依赖性阴离子通道(voltage—dependent anion channel,VDAC)、位于内膜的腺苷酸转移酶(adenine nucleotide translocase,ANT)和位于线粒体基质的亲环素D(cyclophilin-D,CyP—D)组成。多种因素可以调节该孔道的形成和开放,包括小分子物质、信号传导通路以及蛋白与蛋白的相互作用。线粒体通透性转变孔道开放将增加线粒体内膜的通透性,导致线粒体功能紊乱,这一变化可能参与了神经系统疾病的病理发展过程。 展开更多
关键词 线粒体 细胞死亡 神经系统疾病 线柱体通透性转变孔道
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双河油田Ⅳ1-3层系非均相复合驱井网调整研究 被引量:5
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作者 张连锋 梁丽梅 +4 位作者 薛国勤 龙卫江 申乃敏 张伊琳 张小静 《油气藏评价与开发》 CSCD 2020年第6期85-89,共5页
非均相复合驱是提高聚合物驱后油藏采收率的开发技术,而合理的井网调整是提高非均相复合驱增油效果的主要手段。通过数值模拟,对双河油田Ⅳ1-3层系井网调整的井网形式、井距大小、流线转变角度等开展了系统研究,并从技术、经济方面进行... 非均相复合驱是提高聚合物驱后油藏采收率的开发技术,而合理的井网调整是提高非均相复合驱增油效果的主要手段。通过数值模拟,对双河油田Ⅳ1-3层系井网调整的井网形式、井距大小、流线转变角度等开展了系统研究,并从技术、经济方面进行了综合对比论证。研究结果表明:注入体系与原油的黏度比、地层的非均质性对井网流线调整效果具有决定性影响。对于双河油田Ⅳ1-3层系,在充分利用老井的前提下,采用五点法面积井网、井距150~300 m,较大幅度地调整流线角度,能够进一步提高非均相复合驱的降水增油效果。 展开更多
关键词 井网形式 注采井距 线转变 数值模拟 非均相复合驱
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对理想玻色气体性质的一个注记
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作者 沈抗存 《大学物理》 北大核心 1996年第10期49-49,F003,共2页
指出理想玻色气体不可能经绝热过程而发生“相交”.
关键词 玻色气体 相变 转变线 统计物理
全文增补中
In situ study on columnar-equiaxed transition and anaxial columnar dendrite growth of Al-15%Cu alloy by synchrotron radiography 被引量:3
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作者 李发国 东青 +5 位作者 张佼 戴永兵 付亚楠 谢红兰 尹付成 孙宝德 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2014年第7期2112-2116,共5页
Directional solidification of Al-15% (mass fraction) Cu alloy was investigated by in situ and real time radiography which was performed by Shanghai synchrotron radiation facility (SSRF). The imaging results reveal... Directional solidification of Al-15% (mass fraction) Cu alloy was investigated by in situ and real time radiography which was performed by Shanghai synchrotron radiation facility (SSRF). The imaging results reveal that columnar to equiaxed transition (CET) is provoked by external thermal disturbance. The detaching and floating of fragments of dendrite arms are the prelude of the transition when the solute boundary layer in front of the solid-liquid interface is thin. And the dendrite triangular tip is the fracture sensitive zone. When the conditions are suitable, new dendrites can sprout and grow up. This kind of dendrite has no obvious stem and is named anaxial columnar dendrites. 展开更多
关键词 Al-15%Cu alloy directional solidification columnar to equiaxed transition synchrotron X-ray radiography
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Temperature-Dependent Electrical Conductance of Bi Nanowires
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作者 霍鹏程 费广涛 +1 位作者 张阳 张立德 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2015年第1期79-83,I0002,共6页
The single crystal bismuth nanowire arrays grown along [0112] with the diameter of 30 nm was synthesized in the pore of anodic aluminum oxide templates through electrodeposi- tion process. The temperature dependent el... The single crystal bismuth nanowire arrays grown along [0112] with the diameter of 30 nm was synthesized in the pore of anodic aluminum oxide templates through electrodeposi- tion process. The temperature dependent electric conductance of Bi nanowire arrays was measured from 78 K to 320 K. We found that the semimetal-to-semiconductor transition happened around 230 K for 30 nm Bi nanowires oriented along [0112] and the electric con- ductance of the nanowires had a strong temperature dependence. 展开更多
关键词 Bismuth nanowire Semimetal-to-semiconductor transition Electric conduc-tance
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Topology evolutions of silhouettes 被引量:1
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作者 DAI Jun-fei KIM Junho +2 位作者 ZENG Hua-yi GU Xian-feng YAU Shing-tung 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2007年第10期1671-1680,共10页
We give the topology changing of the silhouette in 3D space while others study the projections in an image. Silhou- ettes play a crucial role in visualization, graphics and vision. This work focuses on the global beha... We give the topology changing of the silhouette in 3D space while others study the projections in an image. Silhou- ettes play a crucial role in visualization, graphics and vision. This work focuses on the global behaviors of silhouettes, especially their topological evolutions, such as splitting, merging, appearing and disappearing. The dynamics of silhouettes are governed by the topology, the curvature of the surface, and the view point. In this paper, we work on a more theoretical level to give enu- merative properties of the silhouette including: the integration of signed geodesic curvature along a silhouette is equal to the view cone angle; in elliptic regions, no silhouette can be contained in another one; in hyperbolic regions, if a silhouette is homotopic to a point, then it has at least 4 cusps; finally, critical events can only happen when the view point is on the aspect surfaces (ruled surface of the asymptotic lines of parabolic points with surface itself). We also introduce a method to visualize the evolution of silhouettes, especially all the critical events where the topologies of the silhouettes change. The results have broad applications in computer vision for recognition, graphics for rendering and visualization. 展开更多
关键词 Topological change SILHOUETTE Geodesic curvature CUSP
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Localized Excitations in a Sixth-Order (1+1)-Dimensional Nonlinear Evolution Equation
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作者 SHEN Shou-Feng 《Communications in Theoretical Physics》 SCIE CAS CSCD 2005年第6X期961-963,共3页
In this letter, by means of the Lax pair, Darboux transformation, and variable separation approach, a new exact solution of a sixth-order (1+ 1)-dimensional nonlinear evolution equation, which includes some arbitrary ... In this letter, by means of the Lax pair, Darboux transformation, and variable separation approach, a new exact solution of a sixth-order (1+ 1)-dimensional nonlinear evolution equation, which includes some arbitrary functions,is obtained. Abundant new localized excitations can be found by selecting appropriate functions and they are illustrated both analytically and graphically. 展开更多
关键词 variable separation Lax pair Darboux transformation nonlinear evolution equation localized excitation
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N-Soliton Solutions of General Nonlinear Schrdinger Equation with Derivative 被引量:6
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作者 ZHAI Wen CHEN Deng-Yuan 《Communications in Theoretical Physics》 SCIE CAS CSCD 2008年第5期1101-1104,共4页
The bilinear equation of the genera/nonlinear Schrodinger equation with derivative (GDNLSE) and the N-soliton solutions are obtained through the dependent variable transformation and the Hirota method, respectively.... The bilinear equation of the genera/nonlinear Schrodinger equation with derivative (GDNLSE) and the N-soliton solutions are obtained through the dependent variable transformation and the Hirota method, respectively. The bilinear equation of the nonlinear Schrodinger equation with derivative (DNLSE) and its multisoliton solutions are given by reduction. 展开更多
关键词 general nonlinear Schrodinger equation with derivative nonlinear SchrSdinger equation withderivative Hirota method
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Influence of green tea polyphenols on mitochondrial permeability transition pore and Ca^2+ transport 被引量:1
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作者 沈生荣 于海宁 金超芳 《Journal of Zhejiang University Science》 CSCD 2002年第4期475-479,共5页
The authors investigated the influence of green tea polyphenols (GTPs) on the liver mitochondria permeability transition pore (PTP) opening through mitochondria swelling and change of mitochondria membrane potential. ... The authors investigated the influence of green tea polyphenols (GTPs) on the liver mitochondria permeability transition pore (PTP) opening through mitochondria swelling and change of mitochondria membrane potential. The data showed that GTPs had obvious protective effect on the Ca 2+-induced PTP opening in a dose-dependent manner detected by mitochondria swelling. The results were obtained by measuring the change of mitochondria membrane potential through Rh 123. Further experiments were conducted to examine the detailed influence of GTPs on Ca 2+import and export of mitochondria. The results showed that GTPs had remarkably inhibitory effect on the Ca 2+-induced Ca 2+ import in mitochondria; and that they could accelerate Ca 2+-release from mitochondria. Our data provide an alternate interpretation of the potent protective function of GTPs on cell against apoptosis. 展开更多
关键词 MITOCHONDRIA PTP green tea polyphenols mCICR Ca 2+ transport Mitochondria ΔΨ m
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New Method for Spin Assignment of Superdeformed Rotational Bands
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作者 MULiang-Zhu 《Communications in Theoretical Physics》 SCIE CAS CSCD 2005年第4期719-726,共8页
A new method for spin assignment of superdeformed rotational bands is proposed and it turns out to be more efficient than other methods used before. The application is made to superdeformed bands in A ~ 190 and A ~ ... A new method for spin assignment of superdeformed rotational bands is proposed and it turns out to be more efficient than other methods used before. The application is made to superdeformed bands in A ~ 190 and A ~ 150 mass regions. By analyzing the standard deviation of the fixed γ-ray energies of an SD band in different methods,the advantage of the present method over the other methods is presented. This method brings then a comprehensive interpretation of the methods used in spin assignment. 展开更多
关键词 superdeformed bands spin assignment
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Wronskian Form of N-Solitonic Solution for a Variable-Coefficient Korteweg-de Vries Equation with Nonuniformities
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作者 CAI Ke-Jie TIAN Bo +5 位作者 ZHANG Cheng ZHANG Huan MENG Xiang-Hua LU Xing GENG Tao LIU Wen-Jun 《Communications in Theoretical Physics》 SCIE CAS CSCD 2008年第11期1185-1188,共4页
By the symbolic computation and Hirota method, the bilinear form and an auto-Backlund transformation for a variable-coemcient Korteweg-de Vries equation with nonuniformities are given. Then, the N-solitonic solution i... By the symbolic computation and Hirota method, the bilinear form and an auto-Backlund transformation for a variable-coemcient Korteweg-de Vries equation with nonuniformities are given. Then, the N-solitonic solution in terms of Wronskian form is obtained and verified. In addition, it is shown that the (N - 1)- and N-solitonic solutions satisfy the auto-Backlund transformation through the Wronskian technique. 展开更多
关键词 variable-coefficient KdV equation bilinear auto-Bocklund transformation N-solitonic solution Wronskian determinant
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Registration of image feature points using differential evolution 被引量:1
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作者 ZHANG Hao HUANG Zhan-hua YU Dao-ying 《Optoelectronics Letters》 EI 2005年第1期69-71,共3页
This paper introduces a robust global nonlinear optimizer—differential evolution(DE),which is a simple evolution algorithm to search for an optimal transformation that makes the best alignment of two sets of feature ... This paper introduces a robust global nonlinear optimizer—differential evolution(DE),which is a simple evolution algorithm to search for an optimal transformation that makes the best alignment of two sets of feature points.To map the problem of matching into the framework of DE,the objective function is proportional to the registration error which is measured by Hausdorff distance,while the parameters of transformation are encoded in floating-point as the functional variables.Three termination criteria are proposed for DE.A simulation of 2-dimensional point sets and a similarity transformation are presented to compare the robustness and convergence properties of DE with genetic algorithm’s (GA).And the registration of an object and its contour model have been demonstrated by using of DE to natural images. 展开更多
关键词 图象处理 线性微分演变 理想转化 函数值 收敛性
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Painlevé Analysis,Soliton Solutions and Bcklund Transformation for Extended (2 + 1)-Dimensional Konopelchenko-Dubrovsky Equations in Fluid Mechanics via Symbolic Computation
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作者 许鹏博 高以天 +2 位作者 于鑫 王雷 林国栋 《Communications in Theoretical Physics》 SCIE CAS CSCD 2011年第6期1017-1023,共7页
This paper is to investigate the extended(2+1)-dimensional Konopelchenko-Dubrovsky equations,which can be applied to describing certain phenomena in the stratified shear flow,the internal and shallow-water waves, plas... This paper is to investigate the extended(2+1)-dimensional Konopelchenko-Dubrovsky equations,which can be applied to describing certain phenomena in the stratified shear flow,the internal and shallow-water waves, plasmas and other fields.Painleve analysis is passed through via symbolic computation.Bilinear-form equations are constructed and soliton solutions are derived.Soliton solutions and interactions are illustrated.Bilinear-form Backlund transformation and a type of solutions are obtained. 展开更多
关键词 extended (2 +1)-dimensional Konopelchenko-Dubrovsky equations in fluid mechanics Painleve analysis soliton solutions Backlund transformation symbolic computation
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Monte Carlo Simulation of Coil-to-Globule Transition of Compact Polymer Chains:Role of Monomer Interacting
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作者 Xin-ke Zhang Jia-ye Su 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2018年第6期784-788,733,共6页
Coil-to-globule transitions are fundamental problems existing in polymer science for several decades;however, some features are still unclear, such as the effect of chain monomer interaction. Herein, we use Monte Carl... Coil-to-globule transitions are fundamental problems existing in polymer science for several decades;however, some features are still unclear, such as the effect of chain monomer interaction. Herein, we use Monte Carlo simulation to study the coil-to-globule transition of simple compact polymer chains. We first consider the finite-size effects for a given monomer interaction, where the short chain exhibits a one-step collapse while long chains demonstrate a two-step collapse, indicated by the specific heat. More interestingly, with the decrease of chain monomer interaction, the critical temperatures marked by the peaks of heat capacity shift to low values. A closer examination from the energy, mean-squared radius of gyration and shape factor also suggests the lower temperature of coil-to-globule transition. 展开更多
关键词 Coil-to-globule transition POLYMER Monte Carlo
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Casoratian Solutions to Toda Lattice Via Its Backlund Transformation
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作者 玄其飞 张大军 周静 《Communications in Theoretical Physics》 SCIE CAS CSCD 2010年第3期435-439,共5页
Generalized Casoratian condition and Casoratian solutions of the Toda lattice are given in terms of its bilinear Bgcklund transformation. By choosing suitable Casoratian entries and parameter in the bilinear Bgcklund ... Generalized Casoratian condition and Casoratian solutions of the Toda lattice are given in terms of its bilinear Bgcklund transformation. By choosing suitable Casoratian entries and parameter in the bilinear Bgcklund transformation, we can give transformations among many kinds of solutions. 展开更多
关键词 Toda lattice Casoratian solution bilinear form Backlund transformation
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Research on temperature profiles of honeycomb regenerator with asymptotic analysis
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作者 艾元方 《Journal of Chongqing University》 CAS 2006年第2期77-82,共6页
An asymptotic semi-analytical method for heat transfer in counter-flow honeycomb regenerator is proposed. By introducing a combined heat-transfer coefficient between the gas and solid phase, a heat transfer model is b... An asymptotic semi-analytical method for heat transfer in counter-flow honeycomb regenerator is proposed. By introducing a combined heat-transfer coefficient between the gas and solid phase, a heat transfer model is built based on the thin-walled assumption. The dimensionless thermal equation is deduced by considering solid heat conduction along the passage length. The asymptotic analysis is used for the small parameter of heat conduction term in equation. The first order asymptotic solution to temperature distribution under weak solid heat conduction is achieved after Laplace transformation through the multiple scales method and the symbolic manipulation function in MATLAB. Semi-analytical solutions agree with tests and finite-difference numerical results. It is proved possible for the asymptotic analysis to improve the effectiveness, economics and precision of thermal research on regenerator. 展开更多
关键词 honeycomb regenerator temperature profile asymptotic analysis
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Thermo-mechanical properties of bowl-shaped grinding wheel and machining error compensation for grinding indexable inserts
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作者 张祥雷 姚斌 +3 位作者 陈彬强 孙维方 王萌萌 罗琪 《Journal of Central South University》 SCIE EI CAS CSCD 2015年第10期3830-3836,共7页
In order to meet the technical requirements of grinding the circumferential cutting edge of indexable inserts, thermo-mechanical properties of bowl-shaped grinding wheel in high speed grinding process and the influenc... In order to meet the technical requirements of grinding the circumferential cutting edge of indexable inserts, thermo-mechanical properties of bowl-shaped grinding wheel in high speed grinding process and the influence of dimension variations of the grinding wheel on machining accuracy were investigated. Firstly, the variation trends of the dimension due to centrifugal force generated in different wheel speeds were studied and the effect of stress stiffening and spin softening was presented. Triangular heat flux distribution model was adopted to determine temperature distribution in grinding process. Temperature field cloud pictures were obtained by the finite element software. Then, dimension variation trends of wheel structure were acquired by considering the thermo-mechanical characteristic under combined action of centrifugal force and grinding heat at different speeds. A method of online dynamic monitoring and automatic compensation for dimension error of indexable insert was proposed. By experimental verification, the precision of the inserts satisfies the requirement of processing. 展开更多
关键词 bowl-shaped grinding wheel thermo-mechanical properties indexable insert machining accuracy COMPENSATION
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Extended Mapping Transformation Method and Its Applications to Nonlinear Partial Differential Equation(s)
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作者 ZHAO Hong BAI Cheng-Lin 《Communications in Theoretical Physics》 SCIE CAS CSCD 2005年第3X期473-478,共6页
In this paper, we extend the mapping transformation method through introducing variable coefficients.By means of the extended mapping transformation method, many explicit and exact general solutions with arbitrary fun... In this paper, we extend the mapping transformation method through introducing variable coefficients.By means of the extended mapping transformation method, many explicit and exact general solutions with arbitrary functions for some nonlinear partial differential equations, which contain solitary wave solutions, trigonometric function solutions, and rational solutions, are obtained. 展开更多
关键词 nonlinear partial differential equations extended mapping transformation method exact solutions
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A linear rotary magnetorheological damper for vehicles
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作者 JIANGJiandong LIANGXichang ZHANGBo XIAOJunli 《Journal of Chongqing University》 CAS 2004年第1期11-15,共5页
A new type of linear rotary magnetorheological damper (MRD) is proposed, which consists of a cylinder-type MRD and a screw mechanism to transform a linear motion into revolving motion. It is found that the structure p... A new type of linear rotary magnetorheological damper (MRD) is proposed, which consists of a cylinder-type MRD and a screw mechanism to transform a linear motion into revolving motion. It is found that the structure parameters of MRD have complex relationship with the force of the damper, especially the lead angle, width and radius of the inner rotor. The analyses and simulation calculation of the static magnetic field give some usable data, and experiments of the damping component indicate that the proposed methods is feasible for developing linear rotary MRD. 展开更多
关键词 MR damper (MRD) screw mechanism automotive suspension
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Structure-Property Relations in xWO3-0.31P2O5-0.31B2O3-(0.38-x)Cs2O (0.01 ≤ x ≤0.28) Glasses by IR, UV and EPR Spectroscopic Studies
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作者 Bidhu Bhusan Das Ayyacannou Srinivassan Murugesan Yogapriya 《Journal of Chemistry and Chemical Engineering》 2011年第4期369-375,共7页
Glasses in the series of xWO3-0.31P2O5-0.31B2O3-(0.38-x)Cs2O (0.01 ≤ x ≤0.28) (G1-G4: x= 0.01, 0.1, 0.19, 0.28) were prepared by sol-gel method. Glassy phase in the samples were ascertained by powder X-ray d... Glasses in the series of xWO3-0.31P2O5-0.31B2O3-(0.38-x)Cs2O (0.01 ≤ x ≤0.28) (G1-G4: x= 0.01, 0.1, 0.19, 0.28) were prepared by sol-gel method. Glassy phase in the samples were ascertained by powder X-ray diffraction pattern. Differential scanning calorimetry (DSC) traces of the samples show glass transition temperature Tg, in the range 247-253 ℃. IR spectra at 300 K of G1-G4 show the presence of [WO6], [WO4], [PO4]^3-, [PO3]^2-, [BO4]^+, [BO3] units in the glass matrix. Observed electron paramagnetic resonance (EPR) lineshapes show two signals with very different intensities which are associated with W^5+ (5d^1) and Mo^5+ (4d^1) (impurity) paramagnetic sites. Signal with values ofg factors in the range 1.68 〈 g⊥ 〈 1.72 and 1.58 〈 gⅡ 〈 1.62 are due to W^5+ ions present in axially distorted octahedral symmetry. The optical absorption spectra show that the W^5+ ions have pyramidal coordination, involving a tungstyl ion WO^3+ (C4v symmetry). EPR and optical studies suggest the existence of blocks of octahedra linked by tungsten clusters. 展开更多
关键词 Sol-gel method oxide glasses W^5+ ion EPR small polaron optical absorption
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