期刊文献+
共找到28,313篇文章
< 1 2 250 >
每页显示 20 50 100
Global Existence and Blow-up of Solutions for Fourth-order Parabolic Equation with p(x)-Laplacian and Variable Exponents
1
作者 YANG Chunxiao YU Lifei DUAN Chenyan 《数学进展》 北大核心 2026年第1期221-239,共19页
In this paper,we consider the fourth-order parabolic equation with p(x)Laplacian and variable exponent source ut+∆^(2)u−div(|■u|^(p(x)−2■u))=|u|^(q(x))−1u.By applying potential well method,we obtain global existence... In this paper,we consider the fourth-order parabolic equation with p(x)Laplacian and variable exponent source ut+∆^(2)u−div(|■u|^(p(x)−2■u))=|u|^(q(x))−1u.By applying potential well method,we obtain global existence,asymptotic behavior and blow-up of solutions with initial energy J(u_(0))≤d.Moreover,we estimate the upper bound of the blow-up time for J(u_(0))≤0. 展开更多
关键词 fourth-order parabolic equation variable exponent source global existence asymptotic behavior BLOW-UP
原文传递
NONEXISTENCE AND EXISTENCE OF SUPERSOLUTIONS FOR HIGHER ORDER SEMILINEAR EQUATIONS IN EXTERIOR DOMAINS
2
作者 Xianmei ZHOU 《Acta Mathematica Scientia》 2025年第5期1920-1941,共22页
In this paper,we study the weighted higher order semilinear equation in an exterior domain(-△)^(m)u=|x|^(α)g(u)in R^(N)\B_(R_(0)),where N≥1,m≥2 are integers,α>-2m,g is a continuous and nondecreasing function i... In this paper,we study the weighted higher order semilinear equation in an exterior domain(-△)^(m)u=|x|^(α)g(u)in R^(N)\B_(R_(0)),where N≥1,m≥2 are integers,α>-2m,g is a continuous and nondecreasing function in(0,+∞)and positive in(0,+∞),B_(R_(0))is the ball of the radius R0 centered at the origin.We prove that a positive supersolution of the problem which verifies(-△)_(i)u>0 in R^(N)\B_(R_(0))(i=0,…,m-1)exists if and only if N>2m and∫_(0)^(δ)g(t)/t^(2(N-m)+α/N-2m)dt<∞,,for someδ>0.We further obtain some existence and nonexistence results for the positive solution to the Dirichlet problem when g(u)=u^(p)with p>1,by using the Pohozaev identity and an embedding lemma of radial Sobolev spaces. 展开更多
关键词 higher order equations exterior domains Liouville theorem existence super-solutions
在线阅读 下载PDF
LONG TIME EXISTENCE FOR THE NON-ISENTROPIC SLIGHTLY COMPRESSIBLE FLUID MODEL OF KORTEWEG TYPE
3
作者 Qiangchang JU Jianjun XU 《Acta Mathematica Scientia》 2025年第2期416-445,共30页
We investigate the long time existence of strong solutions to the initial value problem for the three-dimensional non-isentropic compressible Navier-Stokes-Korteweg system.Under the conditions of slight density and te... We investigate the long time existence of strong solutions to the initial value problem for the three-dimensional non-isentropic compressible Navier-Stokes-Korteweg system.Under the conditions of slight density and temperature variations,we verify that the full compressible Navier-Stokes-Korteweg equations admit a unique strong solution as long as the solution of the limiting system exists,when the Mach number is sufficiently small.Furthermore,we deduce the uniform convergence of strong solutions for the compressible system toward those for the corresponding incompressible system on the time interval in which the solution exists. 展开更多
关键词 non-isentropic compressible Navier-Stokes-Korteweg equations low Mach num-ber limit long time existence strong solution
在线阅读 下载PDF
New criteria on the existence and global exponential stability of periodic solutions for quaternion-valued cellular neural networks
4
作者 LI Ai-ling ZHOU Zheng ZHANG Zheng-qiu 《Applied Mathematics(A Journal of Chinese Universities)》 2025年第3期523-542,共20页
In this paper,a class of quaternion-valued cellular neural networks(QVCNNS)with time-varying delays are considered.Combining graph theory with the continuation theorem of Mawhin’s coincidence degree theory as well as... In this paper,a class of quaternion-valued cellular neural networks(QVCNNS)with time-varying delays are considered.Combining graph theory with the continuation theorem of Mawhin’s coincidence degree theory as well as Lyapunov functional method,we establish new criteria on the existence and exponential stability of periodic solutions for QVCNNS by removing the assumptions for the boundedness on the activation functions and the assumptions that the values of the activation functions are zero at origin.Hence,our results are less conservative and new. 展开更多
关键词 the existence of periodic solutions exponential stability quaternion-valued cellular neural networks combining graph theory with Mawhin’s continuation theorem of coincidence degree theory Lyapunov function method inequality techniques
在线阅读 下载PDF
being、essence和existence——托马斯·阿奎那存在论思想探析 被引量:1
5
作者 刘素民 《武汉大学学报(人文科学版)》 CSSCI 北大核心 2010年第6期720-727,共8页
托马斯.阿奎那的形而上学是以是(being)为中心、以本质(essence)和存在(existence)的关系学说为枢纽的存在论。阿奎那认为,形而上学或存在论所探讨的特殊的固有对象即是是(to on,esse,being)自身,或者称之为是之所以为是(esse in quantu... 托马斯.阿奎那的形而上学是以是(being)为中心、以本质(essence)和存在(existence)的关系学说为枢纽的存在论。阿奎那认为,形而上学或存在论所探讨的特殊的固有对象即是是(to on,esse,being)自身,或者称之为是之所以为是(esse in quantum esse,being as beinginjeneral)。他在论证是自身时强调实在意义上的是重于逻辑意义的是。是(being)包括本质(essence)与存在(existence);本质(essence)与存在(existence)皆为是者(beings)。而存在(existence)先于本质(essence);存在(existence)是是(being)之最具体的、个别的、实体的、独一无二的完美实现(act)。托马斯.阿奎那的存在论哲学颠覆了传统哲学中存在与本质的位置,它以一种存在主义代替本质主义,从而在形而上学历史上掀起一场革命。 展开更多
关键词 BEING ESSENCE existence
在线阅读 下载PDF
The Existence of Generalized Solutions for a Nonhomogeneous Boundary Value Problem
6
作者 孙应飞 周美珂 范天佑 《Journal of Beijing Institute of Technology》 EI CAS 1998年第3期210-214,共5页
Aim The existence of generalized solution for a class of nonlinear partial differential equations with nonhanogeneous boundary condition was investigated. This problem arises from polymer processing concerned with the... Aim The existence of generalized solution for a class of nonlinear partial differential equations with nonhanogeneous boundary condition was investigated. This problem arises from polymer processing concerned with the first initial-boundary value problem or the nonstationary floW of non-Newtonian viscous incompressiblee fluid through the slit dice. MethodsThe monotone operator theory and the Schauder's fixal point theorem were used. Results and Conclusion The existence theorem of generalized solutions for a the of nonlinear partial differential equations with nonhormogeneous boundary condition is proved under reasonable conditions 展开更多
关键词 Navier-Stokes equation monotone operator existence
在线阅读 下载PDF
“Is”的家族相似性与“Existence”的乡愁 被引量:2
7
作者 韩东晖 《科学技术哲学研究》 CSSCI 北大核心 2012年第6期6-11,共6页
关于"Is"的"弗雷格-罗素多义性论题"一经提出,就成为分析哲学家普遍接受的共识,有些哲学史家还将其用于考察哲学史、特别是古希腊哲学史中的"to on/Being"问题。这一论题的根源可以追溯至亚里士多德,其... 关于"Is"的"弗雷格-罗素多义性论题"一经提出,就成为分析哲学家普遍接受的共识,有些哲学史家还将其用于考察哲学史、特别是古希腊哲学史中的"to on/Being"问题。这一论题的根源可以追溯至亚里士多德,其基本思路在康德、密尔那里已然成型,而在弗雷格那里得到清晰的界定。维特根斯坦用家族相似性方法观察了"Is"的用法。海德格尔早期从生存论出发为作为"存在"的"Sein/Is"找到了新的"家"。在西学中译中,汉语缺乏西文中兼系词功能与存在用法于一身的具有屈折变化的系词,因此找不到与Being直接对应的现成译名,这未免令人遗憾。我们现在所最需要的,应该是一部比较详细的"Is"演变的概念史,以更为深入的研究"Is"的多重用法的家族相似性。 展开更多
关键词 存在 弗雷格-罗素多义性论题 维特根斯坦 海德格尔 欣提卡
原文传递
Existence of Positive Solutions for Nonlinear Conjugate Boundary Value Problems
8
作者 菅典兵 董正华 《Chinese Quarterly Journal of Mathematics》 CSCD 2002年第2期87-93,共7页
The present paper is concerned with the existence of positive solutions of the (k,n-k) conjugate boundary value problems(-1) n-k u (h) (t)=λa(t)f(u(t)),t∈(0,1), u (i) (0)=0,0≤i≤k-1, u (j) (0)=0,0... The present paper is concerned with the existence of positive solutions of the (k,n-k) conjugate boundary value problems(-1) n-k u (h) (t)=λa(t)f(u(t)),t∈(0,1), u (i) (0)=0,0≤i≤k-1, u (j) (0)=0,0≤j≤n-k-1,where λ is a positive parmeter. Krasnoselsii’s fixed point theorem is employed to obtain the existence criteria for positive solution. 展开更多
关键词 existence theorem positive solutions conjugate boundary value problem
在线阅读 下载PDF
An Existence Theorem of Positive Solution for Fourth-order Superlinear Semipositone Eigenvalue Problems
9
作者 江秀芬 姚庆六 《Chinese Quarterly Journal of Mathematics》 CSCD 2001年第2期64-68,共5页
In this paper we investigate the existence of positive solution for a class of fourth_order superlinear semipositone eigenvalue problems. This class of problems usually describes the deformation of the elastic beam wh... In this paper we investigate the existence of positive solution for a class of fourth_order superlinear semipositone eigenvalue problems. This class of problems usually describes the deformation of the elastic beam whose both end_points are fixed. 展开更多
关键词 elastic beam equation existence of positive solution SEMIPOSITONE fixed point theorem on cone
在线阅读 下载PDF
On existence and uniqueness of the solution of elastoplastic contact problems
10
作者 郭小明 《Journal of Southeast University(English Edition)》 EI CAS 2009年第2期232-235,共4页
Contact problems and elastoplastic problems are unified and described by the variational inequality formulation, in which the constraints of the constitutional relations for elastoplastic materials and the contact con... Contact problems and elastoplastic problems are unified and described by the variational inequality formulation, in which the constraints of the constitutional relations for elastoplastic materials and the contact conditions are relaxed totally. First, the coerciveness of the functional is proved. Then the uniqueness of the solution of variational inequality for the elastoplastic contact problems is demonstrated. The existence of the solution is also demonstrated according to the sufficient conditions for the solution of the elliptic variational inequality. A mathematical foundation is developed for the variational extremum principle of elastoplastic contact problems. The developed variational extremum forms can give an effective and strict mathematical modeling to solve contact problems with mathematical programming. 展开更多
关键词 ELASTOPLASTIC contact problem existence UNIQUENESS COERCIVENESS variational extremum form
在线阅读 下载PDF
China English——An Objective Existence as a Performance Variety
11
作者 黄春燕 《语言与文化研究》 2008年第1期187-192,共6页
China English is an objective existence as a performance variety used in China.It is based on standard English and possesses Chinese characteristics.The Chinese characteristics of China English are reflected in the ph... China English is an objective existence as a performance variety used in China.It is based on standard English and possesses Chinese characteristics.The Chinese characteristics of China English are reflected in the phonology,vocabulary,syntax,rhetoric and text,particularly in the vocabulary.This essay will discuss the features of China English from the following three aspects: the development of English in China;the comparison between China English,Pidgin English and Chinese English and the Chinese words borrowed by English. 展开更多
关键词 China ENGLISH objective existence PERFORMANCE VARI
原文传递
GLOBAL EXISTENCE AND BLOW-UP PHENOMENA OF CLASSICAL SOLUTIONS FOR THE SYSTEM OF COMPRESSIBLE ADIABATIC FLOW THROUGH POROUS MEDIA
12
作者 刘法贵 孔德兴 《应用数学和力学》 EI CSCD 北大核心 2004年第6期643-652,共10页
By means of maximum principle for nonlinear hyperbolic systems, the results given by HSIAO Ling and D. Serre was improved for Cauchy problem of compressible adiabatic flow through porous media, and a complete result o... By means of maximum principle for nonlinear hyperbolic systems, the results given by HSIAO Ling and D. Serre was improved for Cauchy problem of compressible adiabatic flow through porous media, and a complete result on the global existence and the blow-up phenomena of classical solutions of these systems. These results show that the dissipation is strong enough to preserve the smoothness of ‘small ’ solution. 展开更多
关键词 多孔介质 可压缩流体力学 方程组 经典解 整体存在性 破裂
在线阅读 下载PDF
Global existence and blow up of a degenerate parabolic system 被引量:2
13
作者 杨明 《Journal of Southeast University(English Edition)》 EI CAS 2003年第4期427-431,共5页
This paper deals with positive solutions of a degenerate parabolic system: u t= Δ u m+ v p ln α(h+u), v t= Δ v n+u q ln β(h+v) with homogeneous Dirichlet boundary conditions and positive in... This paper deals with positive solutions of a degenerate parabolic system: u t= Δ u m+ v p ln α(h+u), v t= Δ v n+u q ln β(h+v) with homogeneous Dirichlet boundary conditions and positive initial conditions. This system describes the processes of diffusion of heat and burning in two component continuous media with nonlinear conductivity and volume energy release. We obtain the global existence and blow up results of the solution relying on comparison with carefully constructed upper solutions and lower solutions. 展开更多
关键词 parabolic system DEGENERATE global existence blow up
在线阅读 下载PDF
BOUNDEDNESS OF SOLUTIONS AND EXISTENCEOF LIMIT CYCLES FOR A NONLINEAR SYSTEMOF DIFFERENTIAL EQUATIONS 被引量:6
14
作者 黄立宏 陈明博 《Acta Mathematica Scientia》 SCIE CSCD 1998年第1期113-120,共8页
In this paper, author obtain sufficient conditions for the boundedness of solutions and the existence of limit cycles of the nonlinear differential system dx/dt = p(y), dy/dt = -q(y)h(x,y) - g(x) without the tradition... In this paper, author obtain sufficient conditions for the boundedness of solutions and the existence of limit cycles of the nonlinear differential system dx/dt = p(y), dy/dt = -q(y)h(x,y) - g(x) without the traditional assumptions 'h(x,y) greater than or equal to 0 for \x\ sufficiently large' and 'integral(0)(+/-infinity) g(x)dx = +infinity'. 展开更多
关键词 nonlinear differential system BOUNDEDNESS existence limit cycle
在线阅读 下载PDF
BLOW-UP AND GLOBAL EXISTENCE FOR A COUPLED SYSTEM OF DEGENERATE PARABOLIC EQUATIONS IN A BOUNDED DOMAIN 被引量:7
15
作者 穆春来 胡学刚 +1 位作者 李玉环 崔泽键 《Acta Mathematica Scientia》 SCIE CSCD 2007年第1期92-106,共15页
This article deals with the conditions that ensure the blow-up phenomenon or its absence for solutions of the system ut= △u^l + u^p1v^q1 and vt = △v ^m + u^p2 v^q2 with homogeneous Dirichlet boundary conditions.... This article deals with the conditions that ensure the blow-up phenomenon or its absence for solutions of the system ut= △u^l + u^p1v^q1 and vt = △v ^m + u^p2 v^q2 with homogeneous Dirichlet boundary conditions. The results depend crucially on the sign of the difference p2q1 - (l -p1)(m- q2), the initial data, and the domain Ω. 展开更多
关键词 Global existence BLOW-UP degenerate parabolic system
在线阅读 下载PDF
AN EXISTENCE THEOREM OF POSITIVE SOLUTIONS FOR ELASTIC BEAM EQUATION WITH BOTH FIXED END-POINTS 被引量:12
16
作者 Jiang Xiufen Yao Qingliuof Math., Northwest Normal Univ., Lanzhou 730070. 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2001年第3期237-240,共4页
By using the degree theory on cone an existence theorem of positive solution for a class of fourth-order two-point BVP's is obtained. This class of BVP's usually describes the deformation of the elastic beam w... By using the degree theory on cone an existence theorem of positive solution for a class of fourth-order two-point BVP's is obtained. This class of BVP's usually describes the deformation of the elastic beam with both fixed end-points. 展开更多
关键词 Elastic beam equation positive solution existence fixed point theorem on cone.
在线阅读 下载PDF
A NECESSARY AND A SUFFICIENT CONDITION FOR THE EXISTENCE OF THE POSITIVE RADIAL SOLUTIONS TO HESSIAN EQUATIONS AND SYSTEMS WITH WEIGHTS 被引量:7
17
作者 Dragos-Patru COVEI 《Acta Mathematica Scientia》 SCIE CSCD 2017年第1期47-57,共11页
In this article, we consider the existence of positive radial solutions for Hessian equations and systems with weights and we give a necessary condition as well as a sufficient condition for a positive radial solution... In this article, we consider the existence of positive radial solutions for Hessian equations and systems with weights and we give a necessary condition as well as a sufficient condition for a positive radial solution to be large. The method of proving theorems is essentially based on a successive approximation technique. Our results complete and improve a work published recently by Zhang and Zhou(existence of entire positive k-convex radial solutions to Hessian equations and systems with weights. Applied Mathematics Letters,Volume 50, December 2015, Pages 48–55). 展开更多
关键词 existence Keller-Osserman condition k-Hessian equation and system
在线阅读 下载PDF
ON THE EXISTENCE AND STABILITY OF BOUNDARY VALUE PROBLEM FOR DIFFERENTIAL EQUATION WITH HILFER-KATUGAMPOLA FRACTIONAL DERIVATIVE 被引量:5
18
作者 E.M.ELSAYED S.HARIKRISHNAN K.KANAGARAJAN 《Acta Mathematica Scientia》 SCIE CSCD 2019年第6期1568-1578,共11页
In this paper, we discuss the existence, uniqueness and stability of boundary value problem for differential equation with Hilfer-Katugampola fractional derivative. The arguments are based upon Schaefer's fixed po... In this paper, we discuss the existence, uniqueness and stability of boundary value problem for differential equation with Hilfer-Katugampola fractional derivative. The arguments are based upon Schaefer's fixed point theorem, Banach contraction principle and Ulam type stability. 展开更多
关键词 Hilfer-Katugampola fractional DERIVATIVE boundary condition existence Ulam STABILITY
在线阅读 下载PDF
THE LOCAL AND GLOBAL EXISTENCE OF THE SOLUTIONS OF HYPERBOLIC-PARABOLIC SYSTEM MODELING BIOLOGICAL PHENOMENA 被引量:6
19
作者 吴少华 陈化 李维喜 《Acta Mathematica Scientia》 SCIE CSCD 2008年第1期101-116,共16页
The authors prove the local existence and uniqueness of weak solution of a hyperbolic-parabolic system and establish the global existence of the weak solution for this system for the spatial dimension n = 1.
关键词 Hyperbolic-parabolic system chemosensitive movement external signal global existence
在线阅读 下载PDF
GLOBAL EXISTENCE, UNIFORM DECAY AND EXPONENTIAL GROWTH FOR A CLASS OF SEMI-LINEAR WAVE EQUATION WITH STRONG DAMPING 被引量:8
20
作者 陈化 刘功伟 《Acta Mathematica Scientia》 SCIE CSCD 2013年第1期41-58,共18页
In this paper, we consider the nonlinearly damped semi-linear wave equation associated with initial and Dirichlet boundary conditions. We prove the existence of a local weak solution and introduce a family of potentia... In this paper, we consider the nonlinearly damped semi-linear wave equation associated with initial and Dirichlet boundary conditions. We prove the existence of a local weak solution and introduce a family of potential wells and discuss the invariants and vacuum isolating behavior of solutions. Furthermore, we prove the global existence of solutions in both cases which are polynomial and exponential decay in the energy space respectively, and the asymptotic behavior of solutions for the cases of potential well family with 0 〈 E(0) 〈 d. At last we show that the energy will grow up as an exponential function as time goes to infinity, provided the initial data is large enough or E(0) 〈 0. 展开更多
关键词 strong damping nonlinear damping global existence polynomial decay exponential decay exponential growth
在线阅读 下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部