期刊文献+
共找到152,280篇文章
< 1 2 250 >
每页显示 20 50 100
ASYMPTOTIC BEHAVIOUR OF EIGENVALUES FOR THE DISCONTINUOUS BOUNDARY-VALUE PROBLEM WITH FUNCTIONAL-TRANSMISSION CONDITIONS 被引量:11
1
作者 O.Sh.Mukhtarov Department of Mathematics, Science and Arts Faculty, Gaziosmanpasa University, Tokat, TurkeyMustafa Kandemir Department of Mathematics, Faculty of A mas y a Education, Ondokuz Mayis University, Amasya, Turkey 《Acta Mathematica Scientia》 SCIE CSCD 2002年第3期335-345,共11页
In this study, the boundary-value problem with eigenvalue parameter generated by the differential equation with discontinuous coefficients and boundary conditions which contains not only endpoints of the considered in... In this study, the boundary-value problem with eigenvalue parameter generated by the differential equation with discontinuous coefficients and boundary conditions which contains not only endpoints of the considered interval, but also point of discontinuity and linear functionals is investigated. So, the problem is not pure boundary-value. The authors single out a class of linear functionals and find simple algebraic conditions on coefficients, which garantee the existence of infinit number eigenvalues. Also the asymptotic formulas for eigenvalues are found. 展开更多
关键词 Asymptotic behaviour of eigenvalues boundary-value problems functional-conditions discontinuous coefficients
下载PDF
Solvability on boundary-value problems of elasticity of three-dimensional quasicrystals 被引量:1
2
作者 郭丽辉 范天佑 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2007年第8期1061-1070,共10页
Weak solution (or generalized solution) for the boundary-value problems of partial differential equations of elasticity of 3D (three-dimensional) quasicrystals is given, in which the matrix expression is used. In ... Weak solution (or generalized solution) for the boundary-value problems of partial differential equations of elasticity of 3D (three-dimensional) quasicrystals is given, in which the matrix expression is used. In terms of Korn inequality and theory of function space, we prove the uniqueness of the weak solution. This gives an extension of existence theorem of solution for classical elasticity to that of quasicrystals, and develops the weak solution theory of elasticity of 2D quasicrystals given by the second author of the paper and his students. 展开更多
关键词 QUASICRYSTAL ELASTICITY boundary-value problem weak solution SOLVABILITY
下载PDF
Study on the Existence of Sign-Changing Solutions of Case Theory Based a Class of Differential Equations Boundary-Value Problems 被引量:1
3
作者 Hongwei Ji 《Advances in Pure Mathematics》 2017年第12期686-691,共6页
By using the fixed point theorem under the case structure, we study the existence of sign-changing solutions of A class of second-order differential equations three-point boundary-value problems, and a positive soluti... By using the fixed point theorem under the case structure, we study the existence of sign-changing solutions of A class of second-order differential equations three-point boundary-value problems, and a positive solution and a negative solution are obtained respectively, so as to popularize and improve some results that have been known. 展开更多
关键词 Case Theory boundary-value problemS Fixed POINT THEOREM Sign-Changing SOLUTIONS
下载PDF
THE MIXED BOUNDARY-VALUE PROBLEM FOR NON-LOCAL ASYMMETRIC ELASTICITY 被引量:1
4
作者 戴天民 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2000年第1期29-34,共6页
In this paper, the equations of motion and all boundary conditions as well as the energy equation for non_local asymmetric elasticity are derived together from the complete principles of virtual work and virtual power... In this paper, the equations of motion and all boundary conditions as well as the energy equation for non_local asymmetric elasticity are derived together from the complete principles of virtual work and virtual power as well as the generalized Piola theorem. Adding the boundary conditions presented here to the results by Gao Jian and Dai Tianmin,the mixed boundary_value problem of the non_local asymmetric linear elasticity are formulated. 展开更多
关键词 non_local asymmetric elasticity principles of virtual work and power mixed boundary_value problem
下载PDF
Logarithmic Sine and Cosine Transforms and Their Applications to Boundary-Value Problems Connected with Sectionally-Harmonic Functions
5
作者 Mithat Idemen 《Applied Mathematics》 2013年第2期378-386,共9页
Let stand for the polar coordinates in R2, ?be a given constant while satisfies the Laplace equation in the wedge-shaped domain or . Here αj(j = 1,2,...,n + 1) denote certain angles such that αj αj(j = 1,2,...,n + ... Let stand for the polar coordinates in R2, ?be a given constant while satisfies the Laplace equation in the wedge-shaped domain or . Here αj(j = 1,2,...,n + 1) denote certain angles such that αj αj(j = 1,2,...,n + 1). It is known that if r = a satisfies homogeneous boundary conditions on all boundary lines ?in addition to non-homogeneous ones on the circular boundary , then an explicit expression of in terms of eigen-functions can be found through the classical method of separation of variables. But when the boundary?condition given on the circular boundary r = a is homogeneous, it is not possible to define a discrete set of eigen-functions. In this paper one shows that if the homogeneous condition in question is of the Dirichlet (or Neumann) type, then the logarithmic sine transform (or logarithmic cosine transform) defined by (or ) may be effective in solving the problem. The inverses of these transformations are expressed through the same kernels on or . Some properties of these transforms are also given in four theorems. An illustrative example, connected with the heat transfer in a two-part wedge domain, shows their effectiveness in getting exact solution. In the example in question the lateral boundaries are assumed to be non-conducting, which are expressed through Neumann type boundary conditions. The application of the method gives also the necessary condition for the solvability of the problem (the already known existence condition!). This kind of problems arise in various domain of applications such as electrostatics, magneto-statics, hydrostatics, heat transfer, mass transfer, acoustics, elasticity, etc. 展开更多
关键词 INTEGRAL Transforms Harmonic Functions WEDGE problemS boundary-value problemS Logarithmic SINE TRANSFORM Logarithmic COSINE TRANSFORM
下载PDF
A Numerical Method for Singular Boundary-Value Problems
6
作者 Abdalkaleg Hamad M. Tadi Miloje Radenkovic 《Journal of Applied Mathematics and Physics》 2014年第9期882-887,共6页
This note is concerned with an iterative method for the solution of singular boundary value problems. It can be considered as a predictor-corrector method. Sufficient conditions for the convergence of the method are i... This note is concerned with an iterative method for the solution of singular boundary value problems. It can be considered as a predictor-corrector method. Sufficient conditions for the convergence of the method are introduced. A number of numerical examples are used to study the applicability of the method. 展开更多
关键词 SINGULAR boundary-value problem Singularly PERTURBED BOUNDARY VALUE problem
下载PDF
AN EFFICIENT FINITE DIFFERENCE METHOD FOR STOCHASTIC LINEAR SECOND-ORDER BOUNDARY-VALUE PROBLEMS DRIVEN BY ADDITIVE WHITE NOISES
7
作者 Mahboub Baccouch 《Journal of Computational Mathematics》 SCIE CSCD 2024年第2期432-453,共22页
In this paper,we develop and analyze a finite difference method for linear second-order stochastic boundary-value problems(SBVPs)driven by additive white noises.First we regularize the noise by the Wong-Zakai approxim... In this paper,we develop and analyze a finite difference method for linear second-order stochastic boundary-value problems(SBVPs)driven by additive white noises.First we regularize the noise by the Wong-Zakai approximation and introduce a sequence of linear second-order SBVPs.We prove that the solution of the SBVP with regularized noise converges to the solution of the original SBVP with convergence order O(h)in the meansquare sense.To obtain a numerical solution,we apply the finite difference method to the stochastic BVP whose noise is piecewise constant approximation of the original noise.The approximate SBVP with regularized noise is shown to have better regularity than the original problem,which facilitates the convergence proof for the proposed scheme.Convergence analysis is presented based on the standard finite difference method for deterministic problems.More specifically,we prove that the finite difference solution converges at O(h)in the mean-square sense,when the second-order accurate three-point formulas to approximate the first and second derivatives are used.Finally,we present several numerical examples to validate the efficiency and accuracy of the proposed scheme. 展开更多
关键词 boundary-value problems Finite-difference method Additive white noise Wiener process Mean-square convergence Wong-Zakai approximation
原文传递
Solution to Boundary-value Problems in Fabrication of High-precision Reflector Panels
8
作者 郝长岭 周贤宾 李小强 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2009年第1期97-104,共8页
The fabrication of high-precision panels for the compact antenna test range (CATR) with a sandwich construction of two aluminum skin-plates and one aluminum middle plate,which are bonded to two aluminum honeycomb core... The fabrication of high-precision panels for the compact antenna test range (CATR) with a sandwich construction of two aluminum skin-plates and one aluminum middle plate,which are bonded to two aluminum honeycomb core-layers poses a lot of tricky problems. Of them,the force analysis of individual skin-layers and the springback calculation of sandwich are of utmost importance. Under reasonable assumptions,by using Fourier expansion of stress function and power series expansion of deflection function,two boun... 展开更多
关键词 boundary-value problems Fourier series finite element method numerical methods weighted residual method
原文传递
Low Regularity Solution of the Initial-Boundary-Value Problem for the "Good" Boussinesq Equation on the Half Line 被引量:1
9
作者 Ru Ying XUE 《Acta Mathematica Sinica,English Series》 SCIE CSCD 2010年第12期2421-2442,共22页
we study an initial-boundary-value problem for the "good" Boussinesq equation on the half line{δt^2u-δx^2u+δx^4u+δx^2u^2=0,t〉0,x〉0. u(0,t)=h1(t),δx^2u(0,t) =δth2(t), u(x,0)=f(x),δtu(x,0)=δx... we study an initial-boundary-value problem for the "good" Boussinesq equation on the half line{δt^2u-δx^2u+δx^4u+δx^2u^2=0,t〉0,x〉0. u(0,t)=h1(t),δx^2u(0,t) =δth2(t), u(x,0)=f(x),δtu(x,0)=δxh(x).The existence and uniqueness of low reguality solution to the initial-boundary-value problem is proved when the initial-boundary data (f, h, h1, h2) belong to the product spaceH^5(R^+)×H^s-1(R^+)×H^s/2+1/4(R^+)×H^s/2+1/4(R^+) 1 The analyticity of the solution mapping between the initial-boundary-data and the with 0 ≤ s 〈 1/2. solution space is also considered. 展开更多
关键词 Boussinesq equation EXISTENCE initial-boundary-value problem
原文传递
THE MIXED BOUNDARY-VALUE PROBLEM IN NONLOCAL ELASTIC THEORY 被引量:2
10
作者 王锐 《Chinese Science Bulletin》 SCIE EI CAS 1989年第16期1340-1344,共5页
The nonlocal theory which confiders interatomic long-range interaction in materials is one of the generalized continuum theories which involve the microstructure characteristic of material media. The basic equations o... The nonlocal theory which confiders interatomic long-range interaction in materials is one of the generalized continuum theories which involve the microstructure characteristic of material media. The basic equations of linear, homogeneous, isotropic, nonlocal elastic solids 展开更多
关键词 NONLOCAL MIXED boundary-value problem BOUNDARY CONDITIONS CRACK
原文传递
Positive Solutions for Semipositone m-point Boundary-value Problems 被引量:8
11
作者 RuYunMA QiaoZhenMA 《Acta Mathematica Sinica,English Series》 SCIE CSCD 2004年第2期273-282,共10页
Let ξ i ∈ (0, 1) with 0 < ξ1 < ξ2 < ··· < ξ m?2 < 1, a i , b i ∈ [0,∞) with and . We consider the m-point boundary-value problem
关键词 Ordinary differential equation Existence of solutions Multi-point boundary value problems Fixed point theorem in cones
原文传递
POSITIVE SOLUTIONS OF m-POINT BOUNDARY-VALUE PROBLEMS 被引量:1
12
作者 Bai Dingyong Xu Yuantong 《Annals of Differential Equations》 2005年第3期237-242,共6页
The paper is concerned with the existence and multiplicity of positive solutions for a nonlinear m-point boundary value problem. The proofs are based on a fixed-point theorem and a fixed-point index theorem in cones.
关键词 positive solutions m-point boundary value problems cone fixed point
原文传递
The Initial-Boundary-Value Problems for the Hirota Equation on the Half-Line
13
作者 Lin HUANG 《Chinese Annals of Mathematics,Series B》 SCIE CSCD 2020年第1期117-132,共16页
An initial boundary-value problem for the Hirota equation on the half-line,0<x<∞, t>0, is analysed by expressing the solution q(x, t) in terms of the solution of a matrix Riemann-Hilbert(RH) problem in the c... An initial boundary-value problem for the Hirota equation on the half-line,0<x<∞, t>0, is analysed by expressing the solution q(x, t) in terms of the solution of a matrix Riemann-Hilbert(RH) problem in the complex k-plane. This RH problem has explicit(x, t) dependence and it involves certain functions of k referred to as the spectral functions. Some of these functions are defined in terms of the initial condition q(x,0) = q0(x), while the remaining spectral functions are defined in terms of the boundary values q(0, t) = g0(t), qx(0, t) = g1(t) and qxx(0, t) = g2(t). The spectral functions satisfy an algebraic global relation which characterizes, say, g2(t) in terms of {q0(x), g0(t), g1(t)}.The spectral functions are not independent, but related by a compatibility condition, the so-called global relation. 展开更多
关键词 HIROTA equation RIEMANN-HILBERT problem Initial-boundary value problem Global relation
原文传递
On Boundary-Value Problems for the Laplacian in Bounded Domains with Micro Inhomogeneous Structure of the Boundaries
14
作者 Gregory A.CHECHKIN Rustem R.GADYL’SHIN 《Acta Mathematica Sinica,English Series》 SCIE CSCD 2007年第2期237-248,共12页
We consider boundary-value problems with rapidly alternating types of boundary conditions. We present the classification of homogenized (limit) problems depending on the ratio of small parameters, which characterize... We consider boundary-value problems with rapidly alternating types of boundary conditions. We present the classification of homogenized (limit) problems depending on the ratio of small parameters, which characterize the diameter of parts of the boundary with different types of boundary conditions. Also we study the respective spectral problem of this type. 展开更多
关键词 HOMOGENIZATION rapidly alternating boundary conditions spectral problems
原文传递
Positive Solutions for Singular Fourth-Order Integral Boundary-Value Problem with p-Laplacian Operator
15
作者 Xing Qiu ZHANG 《Journal of Mathematical Research and Exposition》 CSCD 2010年第3期495-506,共12页
In this paper, we investigate the existence of positive solutions for singular fourthorder integral boundary-value problem with p-Laplacian operator by using the upper and lower solution method and fixed point theorem... In this paper, we investigate the existence of positive solutions for singular fourthorder integral boundary-value problem with p-Laplacian operator by using the upper and lower solution method and fixed point theorem. Nonlinear term may be singular at t= 0 and/or t - 1 and x =0. 展开更多
关键词 p-Laplacian operator singular boundary value problems integral boundary condition positive solution.
下载PDF
Matched Asymptotic Expansions of the Eigenvalues of a 3-D Boundary-Value Problem Relative to Two Cavities Linked by a Hole of Small Size
16
作者 Abderrahmane Bendali M’Barek Fares +1 位作者 Abdelkader Tizaoui Sebastien Tordeux 《Communications in Computational Physics》 SCIE 2012年第2期456-471,共16页
In this article,we consider a domain consisting of two cavities linked by a hole of small size.We derive a numerical method to compute an approximation of the eigenvalues of an elliptic operator without refining in th... In this article,we consider a domain consisting of two cavities linked by a hole of small size.We derive a numerical method to compute an approximation of the eigenvalues of an elliptic operator without refining in the neighborhood of the hole.Several convergence rates are obtained and illustrated by numerical simulations. 展开更多
关键词 Elliptic operator matched asymptotic expansions eigenvalue problem finite elements
原文传递
Association of preschool children behavior and emotional problems with the parenting behavior of both parents 被引量:1
17
作者 Su-Mei Wang Shuang-Qin Yan +4 位作者 Fang-Fang Xie Zhi-Ling Cai Guo-Peng Gao Ting-Ting Weng Fang-Biao Tao 《World Journal of Clinical Cases》 SCIE 2024年第6期1084-1093,共10页
BACKGROUND Parental behaviors are key in shaping children’s psychological and behavioral development,crucial for early identification and prevention of mental health issues,reducing psychological trauma in childhood.... BACKGROUND Parental behaviors are key in shaping children’s psychological and behavioral development,crucial for early identification and prevention of mental health issues,reducing psychological trauma in childhood.AIM To investigate the relationship between parenting behaviors and behavioral and emotional issues in preschool children.METHODS From October 2017 to May 2018,7 kindergartens in Ma’anshan City were selected to conduct a parent self-filled questionnaire-Health Development Survey of Preschool Children.Children’s Strength and Difficulties Questionnaire(Parent Version)was applied to measures the children’s behavioral and emotional performance.Parenting behavior was evaluated using the Parental Behavior Inventory.Binomial logistic regression model was used to analyze the association between the detection rate of preschool children’s behavior and emotional problems and their parenting behaviors.RESULTS High level of parental support/participation was negatively correlated with conduct problems,abnormal hyperactivity,abnormal total difficulty scores and abnormal prosocial behavior problems.High level of maternal support/participation was negatively correlated with abnormal emotional symptoms and abnormal peer interaction in children.High level of parental hostility/coercion was positively correlated with abnormal emotional symptoms,abnormal conduct problems,abnormal hyperactivity,abnormal peer interaction,and abnormal total difficulty scores in children(all P<0.05).Moreover,paternal parenting behaviors had similarly effects on behavior and emotional problems of preschool children compared with maternal parenting behaviors(all P>0.05),after calculating ratio of odds ratio values.CONCLUSION Our study found that parenting behaviors are associated with behavioral and emotional issues in preschool children.Overall,the more supportive or involved the parents are,the fewer behavioral and emotional problems the children experience;conversely,the more hostile or controlling the parents are,the more behavioral and emotional problems the children face.Moreover,the impact of fathers’parenting behaviors on preschool children’s behavior and emotions is no less significant than that of mothers’parenting behaviors. 展开更多
关键词 CHILDREN Preschool age PARENTING BEHAVIORAL Parenting problems
下载PDF
Quafu-Qcover:Explore combinatorial optimization problems on cloud-based quantum computers 被引量:1
18
作者 许宏泽 庄伟峰 +29 位作者 王正安 黄凯旋 时运豪 马卫国 李天铭 陈驰通 许凯 冯玉龙 刘培 陈墨 李尚书 杨智鹏 钱辰 靳羽欣 马运恒 肖骁 钱鹏 顾炎武 柴绪丹 普亚南 张翼鹏 魏世杰 增进峰 李行 龙桂鲁 金贻荣 于海峰 范桁 刘东 胡孟军 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第5期104-115,共12页
We introduce Quafu-Qcover,an open-source cloud-based software package developed for solving combinatorial optimization problems using quantum simulators and hardware backends.Quafu-Qcover provides a standardized and c... We introduce Quafu-Qcover,an open-source cloud-based software package developed for solving combinatorial optimization problems using quantum simulators and hardware backends.Quafu-Qcover provides a standardized and comprehensive workflow that utilizes the quantum approximate optimization algorithm(QAOA).It facilitates the automatic conversion of the original problem into a quadratic unconstrained binary optimization(QUBO)model and its corresponding Ising model,which can be subsequently transformed into a weight graph.The core of Qcover relies on a graph decomposition-based classical algorithm,which efficiently derives the optimal parameters for the shallow QAOA circuit.Quafu-Qcover incorporates a dedicated compiler capable of translating QAOA circuits into physical quantum circuits that can be executed on Quafu cloud quantum computers.Compared to a general-purpose compiler,our compiler demonstrates the ability to generate shorter circuit depths,while also exhibiting superior speed performance.Additionally,the Qcover compiler has the capability to dynamically create a library of qubits coupling substructures in real-time,utilizing the most recent calibration data from the superconducting quantum devices.This ensures that computational tasks can be assigned to connected physical qubits with the highest fidelity.The Quafu-Qcover allows us to retrieve quantum computing sampling results using a task ID at any time,enabling asynchronous processing.Moreover,it incorporates modules for results preprocessing and visualization,facilitating an intuitive display of solutions for combinatorial optimization problems.We hope that Quafu-Qcover can serve as an instructive illustration for how to explore application problems on the Quafu cloud quantum computers. 展开更多
关键词 quantum cloud platform combinatorial optimization problems quantum software
下载PDF
Spectral Asymptotics for Laplacian with Mixed Boundary-value Condition
19
作者 毛仕宽 陈化 《Northeastern Mathematical Journal》 CSCD 2004年第2期131-134,共4页
Let Ω be a non-empty bounded open set in Rn(n ≥1) with boundary (?)Ω=Γ1∪Γ2. WedefineIn this paper, we consider the following variational eigenvalue problem:where △ denotes the Laplacian in Ω. We say that the s... Let Ω be a non-empty bounded open set in Rn(n ≥1) with boundary (?)Ω=Γ1∪Γ2. WedefineIn this paper, we consider the following variational eigenvalue problem:where △ denotes the Laplacian in Ω. We say that the scalar λ is an eigenvalue of (P) if 展开更多
关键词 spectral asymptotics fractal boundary mixed boundary-value condition
下载PDF
Enhancing Critical Path Problem in Neutrosophic Environment Using Python
20
作者 M.Navya Pratyusha Ranjan Kumar 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第9期2957-2976,共20页
In the real world,one of the most common problems in project management is the unpredictability of resources and timelines.An efficient way to resolve uncertainty problems and overcome such obstacles is through an ext... In the real world,one of the most common problems in project management is the unpredictability of resources and timelines.An efficient way to resolve uncertainty problems and overcome such obstacles is through an extended fuzzy approach,often known as neutrosophic logic.Our rigorous proposed model has led to the creation of an advanced technique for computing the triangular single-valued neutrosophic number.This innovative approach evaluates the inherent uncertainty in project durations of the planning phase,which enhances the potential significance of the decision-making process in the project.Our proposed method,for the first time in the neutrosophic set literature,not only solves existing problems but also introduces a new set of problems not yet explored in previous research.A comparative study using Python programming was conducted to examine the effectiveness of responsive and adaptive planning,as well as their differences from other existing models such as the classical critical path problem and the fuzzy critical path problem.The study highlights the use of neutrosophic logic in handling complex projects by illustrating an innovative dynamic programming framework that is robust and flexible,according to the derived results,and sets the stage for future discussions on its scalability and application across different industries. 展开更多
关键词 Classical critical path problem fuzzy critical path problem uncertainty neutrosophic triangular single-valued neutrosophic number neutrosophic critical path problem python programming languag
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部