多晶体中的晶粒取向分布可通过取向分布函数(orientation distribution function,ODF)表示.取向分布函数(ODF)可在Wigner D-函数基下展开,其展开系数称为织构系数.利用Clebsch-Gordan表达式推导出立方晶粒各向异性集合多晶体的弹性张量...多晶体中的晶粒取向分布可通过取向分布函数(orientation distribution function,ODF)表示.取向分布函数(ODF)可在Wigner D-函数基下展开,其展开系数称为织构系数.利用Clebsch-Gordan表达式推导出立方晶粒各向异性集合多晶体的弹性张量显表达式,该弹性张量表达式包含3个材料常数和9个织构系数.为了织构系数的超声波测定,给出了这9个织构系数与超声波速之间的关系式,并通过一个算例来验证这个关系式.展开更多
多晶体的晶粒取向分布可通过取向分布函数(orientation distribution function,ODF)表示,取向分布函数(ODF)可在Wigner D函数基下展开,其展开系数称为织构系数。利用Clebsch-Gordan表达式可推导出立方晶粒多晶体材料的弹性张量显表达式...多晶体的晶粒取向分布可通过取向分布函数(orientation distribution function,ODF)表示,取向分布函数(ODF)可在Wigner D函数基下展开,其展开系数称为织构系数。利用Clebsch-Gordan表达式可推导出立方晶粒多晶体材料的弹性张量显表达式。对于立方晶粒正交板材,其弹性张量中包含3个材料常数和3个织构系数,根据这3个织构系数与超声波速间的关系式,通过超声波实验来测出这3个织构系数。展开更多
The term‘optimization’refers to the process of maximizing the beneficial attributes of a mathematical function or system while minimizing the unfavorable ones.The majority of real-world situations can be modelled as...The term‘optimization’refers to the process of maximizing the beneficial attributes of a mathematical function or system while minimizing the unfavorable ones.The majority of real-world situations can be modelled as an optimization problem.The complex nature of models restricts traditional optimization techniques to obtain a global optimal solution and paves the path for global optimization methods.Particle Swarm Optimization is a potential global optimization technique that has been widely used to address problems in a variety of fields.The idea of this research is to use exponential basis functions and the particle swarm optimization technique to find a numerical solution for the Sine-Gordan equation,whose numerical solutions show the soliton form and has diverse applications.The implemented optimization technique is employed to determine the involved parameter in the basis functions,which was previously approximated as a random number in the work reported till now in the literature.The obtained results are comparable with the results obtained in the literature.The work is presented in the form of figures and tables and is found encouraging.展开更多
We review the irreducible representation of an angular momentum vector operator constructed in terms of spinor algebra. We generalize the idea of spinor approach to study the coupling of the eigenstates of two indepen...We review the irreducible representation of an angular momentum vector operator constructed in terms of spinor algebra. We generalize the idea of spinor approach to study the coupling of the eigenstates of two independent angular momentum vector operators. Utilizing the spinor algebra, we are able to develop a simple way for calculating the SU(2) Clebsch-Gordan(CG) coefficients. The explicit expression for the SU(2) CG coefficients is worked out, and some simple physical examples are presented to illustrate the spinor approach.展开更多
The orientation distribution of crystallites in a polycrystal can be described by the orientation distribution function(ODF) . The ODF can be expanded under the Wigner D-bases. The expanded coefficients in the ODF are...The orientation distribution of crystallites in a polycrystal can be described by the orientation distribution function(ODF) . The ODF can be expanded under the Wigner D-bases. The expanded coefficients in the ODF are called the texture coefficients. In this paper,we use the Clebsch-Gordan expression to derive an explicit expression of the elasticity tensor for an anisotropic cubic polycrystal. The elasticity tensor contains three material constants and nine texture coefficients. In order to measure the nine texture coefficients by ultrasonic wave,we give relations between the nine texture coefficients and ultrasonic propagation velocities. We also give a numerical example to check the relations.展开更多
Let H = uq（sl（2）） or u（sl（2））. By means of the standard basis of polynomial algebras, the Glebsch-Gordan formula and quantum Clebsch-Gordan formula are proved by a unified method, and the explicit formula of t...Let H = uq（sl（2）） or u（sl（2））. By means of the standard basis of polynomial algebras, the Glebsch-Gordan formula and quantum Clebsch-Gordan formula are proved by a unified method, and the explicit formula of the decomposition of V（1）^n into the direct sum of simple modules is given in this paper.展开更多
文摘多晶体中的晶粒取向分布可通过取向分布函数(orientation distribution function,ODF)表示.取向分布函数(ODF)可在Wigner D-函数基下展开,其展开系数称为织构系数.利用Clebsch-Gordan表达式推导出立方晶粒各向异性集合多晶体的弹性张量显表达式,该弹性张量表达式包含3个材料常数和9个织构系数.为了织构系数的超声波测定,给出了这9个织构系数与超声波速之间的关系式,并通过一个算例来验证这个关系式.
文摘多晶体的晶粒取向分布可通过取向分布函数(orientation distribution function,ODF)表示,取向分布函数(ODF)可在Wigner D函数基下展开,其展开系数称为织构系数。利用Clebsch-Gordan表达式可推导出立方晶粒多晶体材料的弹性张量显表达式。对于立方晶粒正交板材,其弹性张量中包含3个材料常数和3个织构系数,根据这3个织构系数与超声波速间的关系式,通过超声波实验来测出这3个织构系数。
文摘The term‘optimization’refers to the process of maximizing the beneficial attributes of a mathematical function or system while minimizing the unfavorable ones.The majority of real-world situations can be modelled as an optimization problem.The complex nature of models restricts traditional optimization techniques to obtain a global optimal solution and paves the path for global optimization methods.Particle Swarm Optimization is a potential global optimization technique that has been widely used to address problems in a variety of fields.The idea of this research is to use exponential basis functions and the particle swarm optimization technique to find a numerical solution for the Sine-Gordan equation,whose numerical solutions show the soliton form and has diverse applications.The implemented optimization technique is employed to determine the involved parameter in the basis functions,which was previously approximated as a random number in the work reported till now in the literature.The obtained results are comparable with the results obtained in the literature.The work is presented in the form of figures and tables and is found encouraging.
基金Supported by the National Natural Science Foundation of China under Grant No.11475016by the Scientific Research Foundation for Returned Scholars,Ministry of Education of China
文摘We review the irreducible representation of an angular momentum vector operator constructed in terms of spinor algebra. We generalize the idea of spinor approach to study the coupling of the eigenstates of two independent angular momentum vector operators. Utilizing the spinor algebra, we are able to develop a simple way for calculating the SU(2) Clebsch-Gordan(CG) coefficients. The explicit expression for the SU(2) CG coefficients is worked out, and some simple physical examples are presented to illustrate the spinor approach.
基金the National Natural Science Foundation of China (Grant Nos. 10562004 and 10662004)the Jiangxi Project to Nature Academic and Technical Leaders in Targeted Areas, and Research Fund for the Doctoral Program of Higher Education (Grant No. 20070403003)
文摘The orientation distribution of crystallites in a polycrystal can be described by the orientation distribution function(ODF) . The ODF can be expanded under the Wigner D-bases. The expanded coefficients in the ODF are called the texture coefficients. In this paper,we use the Clebsch-Gordan expression to derive an explicit expression of the elasticity tensor for an anisotropic cubic polycrystal. The elasticity tensor contains three material constants and nine texture coefficients. In order to measure the nine texture coefficients by ultrasonic wave,we give relations between the nine texture coefficients and ultrasonic propagation velocities. We also give a numerical example to check the relations.
基金the National Natural Science Foundation of China （No. 10471121 10771182+2 种基金 10771183） Sino-German Project （No. GZ310） Nanjing Agricultural University Youth Science and Technology Innovation Foundation （No. KJ05028）.
文摘Let H = uq（sl（2）） or u（sl（2））. By means of the standard basis of polynomial algebras, the Glebsch-Gordan formula and quantum Clebsch-Gordan formula are proved by a unified method, and the explicit formula of the decomposition of V（1）^n into the direct sum of simple modules is given in this paper.
