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Canonical Differential Calculi for Finitely Generated Abelian Groups and Their Fermionic Representations
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作者 DAIJian SONGXing-Chang 等 《Communications in Theoretical Physics》 SCIE CAS CSCD 2002年第4期393-396,共4页
Canonical differential calculi are defined for finitely generated Abelian groups with involutions existing consistently. Two such the canonical calculi are presented. Fermionic representations for canonical calculi ar... Canonical differential calculi are defined for finitely generated Abelian groups with involutions existing consistently. Two such the canonical calculi are presented. Fermionic representations for canonical calculi are defined based on quantized calculi. Fermionic representations for aforementioned two canonical calculi are searched out. 展开更多
关键词 finitely generated Abelian group canonical differential calculus INVOLUTION quantized calculus fermionic representation
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Exact Solutions and Finite Time Stability of Linear Conformable Fractional Systems with Pure Delay
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作者 Ahmed M.Elshenhab Xingtao Wang +1 位作者 Fatemah Mofarreh Omar Bazighifan 《Computer Modeling in Engineering & Sciences》 SCIE EI 2023年第2期927-940,共14页
We study nonhomogeneous systems of linear conformable fractional differential equations with pure delay.By using new conformable delayed matrix functions and the method of variation,we obtain a representation of their... We study nonhomogeneous systems of linear conformable fractional differential equations with pure delay.By using new conformable delayed matrix functions and the method of variation,we obtain a representation of their solutions.As an application,we derive a finite time stability result using the representation of solutions and a norm estimation of the conformable delayedmatrix functions.The obtained results are new,and they extend and improve some existing ones.Finally,an example is presented to illustrate the validity of our theoretical results. 展开更多
关键词 representation of solutions conformable fractional derivative conformable delayed matrix function conformable fractional delay differential equations finite time stability
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Quantum fluctuation in excited states of mesoscopic LC circuits at finite temperature 被引量:1
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作者 王继锁 范洪义 孟祥国 《Chinese Physics B》 SCIE EI CAS CSCD 2010年第3期334-337,共4页
We discuss quantum fluctuation in excited states (named thermo number states) of mesoscopic LC circuits at a finite temperature. By introducing the coherent thermo state into the thermo field dynamics pioneered by U... We discuss quantum fluctuation in excited states (named thermo number states) of mesoscopic LC circuits at a finite temperature. By introducing the coherent thermo state into the thermo field dynamics pioneered by Umezawa and using the natural representation of thermo squeezing operator we can concisely derive the fluctuation. The result shows that the noise becomes larger when either temperature or the excitation number increases. 展开更多
关键词 quantization of LC circuits at finite temperature coherent thermo state representation thermo number state thermo field dynamics
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The Matric Expressionsin Pauli-Dirac Representation
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作者 张学龙 李光惠 《International Journal of Mining Science and Technology》 SCIE EI 1997年第2期81-83,共3页
In this paper Dirce group is constructed on the basis of algebraic properties of α’s and β’s matrices in Dirac equation. It is then establisbed that the dimensions of the matrices must be four (i. e., 4 × 4 m... In this paper Dirce group is constructed on the basis of algebraic properties of α’s and β’s matrices in Dirac equation. It is then establisbed that the dimensions of the matrices must be four (i. e., 4 × 4 matrices), and the concrete formulations of them in Pauli-Dirac representation are derived. 展开更多
关键词 HERMITIAN finite group IRREDUCIBLE representATION EIGENVECTOR
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Fifty years of finite elements——a solid mechanics perspective
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作者 D.R.J.Owen 《Theoretical & Applied Mechanics Letters》 CAS 2012年第5期1-5,共5页
The finite element method has been considered as one of the most significant engineering advances of the twentieth century. This computational methodology has made substantial impact on many fields in science and also... The finite element method has been considered as one of the most significant engineering advances of the twentieth century. This computational methodology has made substantial impact on many fields in science and also has profoundly changed engineering design procedures and practice. This paper, mainly froln a solid mechanics perspective, and the Swansea viewpoint in particular, describes very briefly the origin of the methodology, then summaries selected milestones of the technical developments that have taken place over the last fifty years and illustrates their application to some practical engineering problems. 展开更多
关键词 inite elements isoparametric representation ELASTO-PLASTICITY finite strain mesh adaptiv ity discrete and multi-fracturing modelling
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Discretization of Complex Geometric Domain Through Computer-Based Stair-Step Representation Method for Estimating Water Levels Associated with A Storm
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作者 Md.Mahabub Alam Gour Chandra Paul +5 位作者 Irfan Raju Foyjonnesa Farhana Zannat Eti Mst.Sharmin Banu Dipankar Kumar Md.Emran Ali 《China Ocean Engineering》 SCIE EI CSCD 2022年第5期791-801,共11页
In this paper,an improvement has been made to the approximation technique of a complex domain through the stair-step approach to have a considerable accuracy,minimize computational cost,and avoid the hardship of manua... In this paper,an improvement has been made to the approximation technique of a complex domain through the stair-step approach to have a considerable accuracy,minimize computational cost,and avoid the hardship of manual work.A novel stair-step representation algorithm is used in this regard,where the entire procedure is carried out through our developed MATLAB routine.Arakawa C-grid is used in our approximation with(1/120)°grid resolution.As a test case,the method is applied to approximate the domain covering the area between 15°-23°N latitudes and 85°-95°E longitudes in the Bay of Bengal.Along with the approximation of the land-sea interface,coastal stations are also identified.Approximated land-sea interfaces and coastal stations are found to be in good agreement with the actual ones based on the similarity index,overlap fraction,and extra fraction criteria.The method can be used for approximating an irregular geometric domain to employ the finite difference method in solving problems related to long waves.As a test case,shallow water equations in Cartesian coordinates are solved on the domain of interest for simulating water levels due to the nonlinear tide-surge interaction associated with the storms April 1991 and AILA,2009 along the coast of Bangladesh.The same input except for the discretized domain and bathymetry as that of Paul et al.(2016)is used in our simulation.The results are found to be in reasonable agreement with the observed data procured from Bangladesh Inland Water Transport Authority. 展开更多
关键词 Arakawa C-grid Bay of Bengal coast of Bangladesh finite difference method shallow water equations stair-step representation
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SIMULATION OF FABRIC DRAPE USING A THIN PLATE ELEMENT WITH FINITE ROTATION 被引量:1
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作者 陈明祥 孙庆平 袁铭辉 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 1998年第3期239-247,共9页
The draping behavior of fabric is simulated by using four node quadrilateral thin plate elements with finite rotation. The finite element formulation is based on the total Lagrangian approach. An exact representatio... The draping behavior of fabric is simulated by using four node quadrilateral thin plate elements with finite rotation. The finite element formulation is based on the total Lagrangian approach. An exact representation of finite rotation is introduced. The strain energy function accounting for the material symmetry is obtained by the tensor representation theory. To avoid shear locking, the assumed strain technique for transverse shear is adopted. The conjugate gradient method with a proposed line search algorithm is employed to minimize energy and reach the final shape of fabric. The draping behavior of a rectangular piece of fabric over a rectangular table is simulated. (Author abstract) 9 Refs. 展开更多
关键词 nonlinear finite element cloth draping flexible thin plate finite rotation tensor function representation theory conjugate gradient
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A new finite-dimensional thermal coherent state and its Wigner distribution function
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作者 孟祥国 王继锁 梁宝龙 《Chinese Physics B》 SCIE EI CAS CSCD 2011年第1期371-376,共6页
This paper constructs a new type of finite-dimensional thermal coherent states (FDTCS), which differs from the proceeding thermal coherent state in construction, as realisations of SU(2) Lie algebra. Using the tec... This paper constructs a new type of finite-dimensional thermal coherent states (FDTCS), which differs from the proceeding thermal coherent state in construction, as realisations of SU(2) Lie algebra. Using the technique of integration within an ordered product of operator, it investigates the orthonormality and completeness relation of the FDTCS. Based on the thermal Wigner operator in the thermal entangled state representation, the Wigner function of the FDTCS is obtained. The nonclassical properties of the FDTCS are discussed in terms of the negativity of its Wigner function. 展开更多
关键词 new finite-dimensional thermal coherent state thermal entangled state representation Wigner distribution function
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Equivalence of Paths under the Action of the Real Representation of Sp(n)
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作者 Muminov K. Khodyrovich Juraboyev S. Solyjonovich 《Journal of Applied Mathematics and Physics》 2022年第5期1837-1858,共22页
In this article, we will consider questions of G-equivalence of paths for the case when G was the group of the real representation of a symplectic transformation in an n-dimensional quaternion vector space. In determi... In this article, we will consider questions of G-equivalence of paths for the case when G was the group of the real representation of a symplectic transformation in an n-dimensional quaternion vector space. In determining the solution of this problem, we give an explicit description of differential generators of a differential field of differential rational functions that are invariant under the action of this group. Necessary and sufficient conditions for the G-equivalence of paths in a 4n-dimensional real space are obtained with the help of differential generators. 展开更多
关键词 Real representation Differential Invariant Differential Generators Path in a finite-Dimensional Space
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群在向量空间上的广义作用Ⅱ
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作者 刘秀 《广西民族大学学报(自然科学版)》 CAS 2023年第2期82-86,共5页
在已有定义和结论的基础上,研究群的广义子表示及其直和,推广了若干熟知的结果,使群作用研究方法、局部分析法得到新的应用。
关键词 有限群 向量空间 广义同态 广义作用 广义子表示
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有限群的完全可约广义表示
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作者 刘秀 《南宁师范大学学报(自然科学版)》 2023年第1期7-10,共4页
该文研究有限群的可约广义线性表示及完全可约广义线性表示,证明了当域F的特征不整除有限群G的阶时,G的每个广义F-线性表示都是完全可约的.这是对经典的Maschke定理的一个推广.
关键词 有限群 广义表示 可约广义表示 完全可约广义表示
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The Local Theory of Completely 1-Summing Mapping Spaces
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作者 Yafei Zhao Yuanyi Wang 《Journal of Applied Mathematics and Physics》 2023年第6期1570-1579,共10页
In this paper, we investigate local properties in the system of completely 1-summing mapping spaces. We introduce notions of injectivity, local reflexivity, exactness, nuclearity and finite-representability in the sys... In this paper, we investigate local properties in the system of completely 1-summing mapping spaces. We introduce notions of injectivity, local reflexivity, exactness, nuclearity and finite-representability in the system of completely 1-summing mapping spaces. First we obtain that if V has WEP, V is locally reflexive in the system (Ⅱ<sub>1</sub>(⋅,⋅), π<sub>1</sub>(⋅)) if and only if it is locally reflexive in the system (Ⅰ(⋅,⋅), t(⋅)). Furthermore we prove that an operator space V ⊆ B(H) is exact in the system (Ⅱ<sub>1</sub>(⋅,⋅), π<sub>1</sub>(⋅)) if and only if V is finitely representable in {M<sub>n</sub>}<sub>n∈N</sub> in the system (Ⅱ<sub>1</sub>(⋅,⋅), π<sub>1</sub>(⋅)). At last, we show that an operator space V is finitely representable in {M<sub>n</sub>}<sub>n∈N</sub> in the system (Ⅱ<sub>1</sub>(⋅,⋅), π<sub>1</sub>(⋅)) if and only if V = C. 展开更多
关键词 Completely 1-Summing Mapping Space Injectivity NUCLEARITY Local Reflexivity EXACTNESS finite-representability and Operator Space
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有限元分析建模知识表示及重用技术研究 被引量:8
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作者 王平 高德平 刘德仿 《机械科学与技术》 CSCD 北大核心 2005年第11期1316-1319,共4页
鉴于传统有限元建模过程对相关知识处理与组织能力上的不足,没有建立有效机制,保障这些知识的可重用性。本文结合UG/KF提出了基于工程规则的有限元分析建模知识表示及知识重用方法。该方法借助知识表示语言UG/KF,以类的形式对产品有限... 鉴于传统有限元建模过程对相关知识处理与组织能力上的不足,没有建立有效机制,保障这些知识的可重用性。本文结合UG/KF提出了基于工程规则的有限元分析建模知识表示及知识重用方法。该方法借助知识表示语言UG/KF,以类的形式对产品有限元分析建模中的工程规则进行表示,满足了分析建模过程中知识管理的需要,并对有限元分析建模过程中的知识重用提供支持。该方法能较好地重复利用以往的建模知识与专家经验,从而提高有限元分析建模效率和质量。 展开更多
关键词 知识重用 有限元建模 知识表示
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飞机结构有限元模型化的智能化方法应用研究 被引量:7
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作者 徐元铭 龚尧南 《航空学报》 EI CAS CSCD 北大核心 2001年第3期207-211,共5页
针对飞机结构的复杂性 ,提出了适用于飞机结构有限元模型化各阶段的整体式知识表达模型 ,并在此基础上 ,以 NASTRAN软件为依托 ,构造了基于推理和算法任务调度的有限元模型化过程求解模型 ,侧重剖析了模型化各阶段的具体分解任务内容。... 针对飞机结构的复杂性 ,提出了适用于飞机结构有限元模型化各阶段的整体式知识表达模型 ,并在此基础上 ,以 NASTRAN软件为依托 ,构造了基于推理和算法任务调度的有限元模型化过程求解模型 ,侧重剖析了模型化各阶段的具体分解任务内容。通过应用实例 。 展开更多
关键词 有限元模型化 知识表达模型 黑板机制 飞机结构 智能化方法 结构力学
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随机场的模拟及其在堤坡可靠性分析中的应用 被引量:10
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作者 庞小朝 周小文 +1 位作者 温庆博 介玉新 《长江科学院院报》 CSCD 北大核心 2002年第4期27-29,48,共4页
介绍了协方差分解技术和谱代替法两种模拟随机场的方法 ,对两种方法的优缺点作了详细的论述 ,并探讨将谱代替法应用于岩土工程可靠度计算的方法。将协方差分解技术和谱代替法分别应用于蒙特卡罗随机有限元法 ,计算了一个堤坡的局部失效... 介绍了协方差分解技术和谱代替法两种模拟随机场的方法 ,对两种方法的优缺点作了详细的论述 ,并探讨将谱代替法应用于岩土工程可靠度计算的方法。将协方差分解技术和谱代替法分别应用于蒙特卡罗随机有限元法 ,计算了一个堤坡的局部失效概率。经比较认为 ,谱代替法是模拟土性参数随机场的一种有效的方法。 展开更多
关键词 随机场 蒙特卡罗法 随机有限元 谱代替法 可靠性
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航空薄壁结构有限元建模的智能化求解模型研究 被引量:2
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作者 徐元铭 周胜强 龚尧南 《南京航空航天大学学报》 EI CAS CSCD 北大核心 2001年第6期526-530,共5页
介绍了利用 CAD、网格自动剖分和人工智能技术相结合进行航空薄壁结构有限元建模的问题求解框架。着重论述了建模过程中模型演变的四个不同阶段的任务 ,提出了适用于建模各阶段的整体式知识表达模型 ,并对采用黑板机制来组织知识推理和... 介绍了利用 CAD、网格自动剖分和人工智能技术相结合进行航空薄壁结构有限元建模的问题求解框架。着重论述了建模过程中模型演变的四个不同阶段的任务 ,提出了适用于建模各阶段的整体式知识表达模型 ,并对采用黑板机制来组织知识推理和算法任务调度的过程求解模型做了描述。 展开更多
关键词 有限元法 人工智能 知识表达模型 黑板机制 航空薄壁结构
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群与代数的表示理论(迎接ICM2002特约文章) 被引量:2
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作者 张继平 王建磐 +1 位作者 肖杰 丁南庆 《数学进展》 CSCD 北大核心 2001年第6期481-488,共8页
有限群模表示论,代数群与量子群,代数表示论,同调代数与代数K-理论是当前国际数学研究的前沿重点领域,在20世纪得到巨大发展,它们之间的相互交叉融合与综合统一在数学发展中具有鲜明特色.本文简要概述上述研究领域的发展历史... 有限群模表示论,代数群与量子群,代数表示论,同调代数与代数K-理论是当前国际数学研究的前沿重点领域,在20世纪得到巨大发展,它们之间的相互交叉融合与综合统一在数学发展中具有鲜明特色.本文简要概述上述研究领域的发展历史与最新研究进展。 展开更多
关键词 有限群 代数 代数群 量子群 同调代数 代数K-理论 表示理论
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花岗岩粗糙表面动摩擦形态演化 被引量:3
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作者 张磊 王文帅 +3 位作者 苗春贺 单俊芳 王鹏飞 徐松林 《高压物理学报》 CAS CSCD 北大核心 2021年第3期23-33,共11页
冲击过程中岩石界面动摩擦特性对于地震滑移等现象的研究有重要意义。基于分离式霍普金森压杆(SHPB)杆束技术对含倾斜界面的花岗岩进行冲击实验,分别采用光学显微镜和台阶仪,观测较大视场(毫米尺度)和较小视场(亚毫米尺度)下花岗岩界面... 冲击过程中岩石界面动摩擦特性对于地震滑移等现象的研究有重要意义。基于分离式霍普金森压杆(SHPB)杆束技术对含倾斜界面的花岗岩进行冲击实验,分别采用光学显微镜和台阶仪,观测较大视场(毫米尺度)和较小视场(亚毫米尺度)下花岗岩界面粗糙形态。结果表明:微动滑移条件下,表面仍非常粗糙,没有大的凸起,但是对于局部初始较平滑的表面,冲击后由于表面的摩擦作用变得粗糙,很难观察到大位移滑移时的光滑滑移面。采用斜条型有限子群表示,结合微界面相对滑移磨损扩散的控制方程,建立岩石界面粗糙形态动力学演化的描述方法。初步结果验证了此方法的可行性,但需要结合深入的实验观测进行完善。研究结果对界面动摩擦演化过程及其机制的认识具有良好的参考意义。 展开更多
关键词 动摩擦 粗糙表面 分离式霍普金森压杆 有限群表示
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汽轮发电机定子系统固有频率新算法 被引量:4
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作者 邱家俊 卿光辉 胡宇达 《大电机技术》 北大核心 2001年第6期1-4,10,共5页
本文应用群表示理论简化了汽轮发电机定子系统的结构 ,用有限元方法分析了汽轮发电机定子系统二维和三维两种模型的固有振动特性 ,给出了冷态工况的二维和三维模型的模态 ,同时比较了两种模型的分析结果。由模型分析和计算结果可以看出... 本文应用群表示理论简化了汽轮发电机定子系统的结构 ,用有限元方法分析了汽轮发电机定子系统二维和三维两种模型的固有振动特性 ,给出了冷态工况的二维和三维模型的模态 ,同时比较了两种模型的分析结果。由模型分析和计算结果可以看出三维模型更符合实际结构。 展开更多
关键词 汽轮发电机 定子系统 固有频率 算法
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机床组件有限元分析前处理专家系统研究 被引量:2
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作者 倪晓宇 易红 +1 位作者 倪中华 汤文成 《东南大学学报(自然科学版)》 EI CAS CSCD 北大核心 2005年第2期211-215,共5页
根据机床组件有限元分析特点,结合人工智能和有限元商业软件ANSYS,建立了针对机床组件有限元前处理过程的专家系统.首先根据有限元软件的操作流程对专家系统的运行流程进行了设计.通过对专家经验、理论知识、设计手册等知识的搜集和分类... 根据机床组件有限元分析特点,结合人工智能和有限元商业软件ANSYS,建立了针对机床组件有限元前处理过程的专家系统.首先根据有限元软件的操作流程对专家系统的运行流程进行了设计.通过对专家经验、理论知识、设计手册等知识的搜集和分类,运用基于逻辑的规则知识表达模型,将其转换为专家系统知识库中的知识,对有限元前处理知识和结构化知识做了较为详细的描述.同时也对专家系统中知识的推理和计算过程以及知识库的动态更新过程进行了讨论.最后利用机床主轴挠度分析作为实例,进一步讨论和证明了该系统的适应性和可靠性. 展开更多
关键词 专家系统 有限元 前处理 机床组件 人工智能
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