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NONEXISTENCE AND EXISTENCE OF SUPERSOLUTIONS FOR HIGHER ORDER SEMILINEAR EQUATIONS IN EXTERIOR DOMAINS
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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
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LONG TIME EXISTENCE FOR THE NON-ISENTROPIC SLIGHTLY COMPRESSIBLE FLUID MODEL OF KORTEWEG TYPE
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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
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New criteria on the existence and global exponential stability of periodic solutions for quaternion-valued cellular neural networks
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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
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SUFFICIENT CONDITIONS FOR THE EXISTENCE OF PERIODIC SOLUTIONS OF A AUTONOMOUS DIFFERENTIAL SYSTEM 被引量:1
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作者 黄立宏 庚建设 《Acta Mathematica Scientia》 SCIE CSCD 1995年第2期126-135,共10页
In this paper, some sufficient conditions on the existence of non-trivial periodic solutions of the system dx/dt=e(y), dy/dt=- f(x)h(y)- g(x)are obtained, which not only generalize some known results concerning the Li... In this paper, some sufficient conditions on the existence of non-trivial periodic solutions of the system dx/dt=e(y), dy/dt=- f(x)h(y)- g(x)are obtained, which not only generalize some known results concerning the Lienard system in this direction, but also relax or eliminate some traditional assumptions. 展开更多
关键词 autonomous differental SYSTEM periodic solution existence.
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being、essence和existence——托马斯·阿奎那存在论思想探析 被引量:1
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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
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Eco-Reason the Philosophical Thinking on the Limitation Existence 被引量:4
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作者 TangDaixing 《Ecological Economy》 2005年第2期12-18,共7页
The philosophical root of all human beings’ existence crisis in the contemporary times is the philosophy of the unlimited theory. The inner spiritual supporting force is the construction from its theoretical reason t... The philosophical root of all human beings’ existence crisis in the contemporary times is the philosophy of the unlimited theory. The inner spiritual supporting force is the construction from its theoretical reason to its scientific reason. Its essential ideas stem from the people-centered theory, the view of happiness in the material- purposed theory, the communist life style, the material hegemonist principle, and the rational action principles of economic technology. In the 21st century, in order to deal with the dangerous situation of human beings’ exist- ence from the root, the philosophy of the limitation theory must be established, which has the eco-reason as the value support, integrates all the original wisdom of human beings and reflects human’s spiritual needs of the age as well as the direction of human future development. The whole percept of this new philosophy is that “all things have souls”; its basic law of existence is “the ceaseless life circle”; its survival goal is the view of happiness in the harmony of material and spirit; its social action guidance and principle are (environment, society, humanity) the environment ecologism and the integral-and-mutual action principle (of human beings &society, individual &society, and present age & posterity). 展开更多
关键词 limitation theory eco-reason spirit of circulatory life limitation existence principles of limitation existence.
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The Existence of Generalized Solutions for a Nonhomogeneous Boundary Value Problem
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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
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An Existence Theorem of Positive Solution for Fourth-order Superlinear Semipositone Eigenvalue Problems
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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
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Existence of Positive Solutions for Nonlinear Conjugate Boundary Value Problems
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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
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On existence and uniqueness of the solution of elastoplastic contact problems
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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
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EXISTENCE OF POSITIVE RADIAL SOLUTIONS FOR SINGULAR ELLIPTIC SYSTEMS
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作者 Wan Aying Jiang DaqingDept.ofMath.,HulunberCollege,Hailar021008.Dept.ofMath.,NortheastNormalUniv.,Changchun130024 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2001年第2期141-148,共8页
The existence of positive radial solutions to the systems of m(m≥1) semilinear elliptic equations Δu+p(r)f(u)=0,0<A<r<B in annuli with Dirichlet(Dirichlet/Neumann)boundary conditions,is studied,whe... The existence of positive radial solutions to the systems of m(m≥1) semilinear elliptic equations Δu+p(r)f(u)=0,0<A<r<B in annuli with Dirichlet(Dirichlet/Neumann)boundary conditions,is studied,where r=x 2 1+...+x 2 n,n≥1.u=(u 1,...,u m),p(r)f(u)=(p 1(r)f 1(u),...,p m(r)f m(u)), and p(r) may be singular at r=A or r=B,f may be singular at u=0. 展开更多
关键词 Positive radial solution elliptic system SINGULAR existence.
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The Existence of the Solution for Linear Complementary Problem
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作者 寇述舜 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 1995年第7期683-685,共3页
This paper deals with the existince of the solulionlor linear complementaryproblern. The uniqueness theorem of lhe solution for linear compiementary. problem isproved. Two evaniples are given. They show that “M is po... This paper deals with the existince of the solulionlor linear complementaryproblern. The uniqueness theorem of lhe solution for linear compiementary. problem isproved. Two evaniples are given. They show that “M is positive .sermidefinite”neither sufficient nor necessary codition .for te, existence to the solution of linearcomplementary. problem. 展开更多
关键词 linear complementary problem complementary basic feasiblesolution existence. Lemke's complementary pivoting algorithm
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EXISTENCE OF PERIODIC SOLUTIONS OF SYSTEM OF DIFFERENCE EQUATIONS
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作者 Wei Gengping Shen Jianhua 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2006年第3期320-326,共7页
This paper studies the nonautonomous nonlinear system of difference equations △x(n) A(n)x(n) + f(n,x(n)), n∈Z ,(*)where x(n)∈R^N,A(n) = (aij(n))N×N is an N×N matrix, with aij∈C(R,R... This paper studies the nonautonomous nonlinear system of difference equations △x(n) A(n)x(n) + f(n,x(n)), n∈Z ,(*)where x(n)∈R^N,A(n) = (aij(n))N×N is an N×N matrix, with aij∈C(R,R) for i,j = 1,2,3 ,N, and f = (f1,f2,... ,fN)^T ∈C(R×R^N,R^N), satisfying A(t+) = A(t), f(t+ω,z) = f(t, z) for any t∈R, (t, z) ∈R× RN and ∈is a positive integer. Sufficient conditions for the existence of ω-periodic solutions to equations (*) are obtained. 展开更多
关键词 systems of difference equations periodic solutions existence.
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GLOBAL EXISTENCE FOR A SEMILINEAR DIFFERENTIAL SYSTEM
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作者 LI SHUANHU 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 1995年第4期387-398,共12页
In this paper, a semilinear elliptic-parabolic PDE system which arises in a two dimensional groundwater flow problem is studied. Existence and uniqueness results are established via the L ̄p - L ̄q a priori estimates ... In this paper, a semilinear elliptic-parabolic PDE system which arises in a two dimensional groundwater flow problem is studied. Existence and uniqueness results are established via the L ̄p - L ̄q a priori estimates and the inverse function theorem. 展开更多
关键词 L ̄p - L ̄q estimates UNIQUENESS existence.
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China English——An Objective Existence as a Performance Variety
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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
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“Is”的家族相似性与“Existence”的乡愁 被引量:2
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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
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Global existence and blow up of a degenerate parabolic system 被引量:2
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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
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自平衡法检测基桩承载力存在的问题及优化策略探讨
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作者 李剑育 曾庆广 《城市建筑》 2026年第2期221-224,共4页
在基桩承载力检测方面,自平衡检测技术通过整合加载系统、压力监测单元及位移检测模块,实现了对桩基承载性能的高精度量化。此技术以实时、精确、简便的操作特点,在工程实践中被广泛采用。尽管如此,该技术在检测与实际工程桩受力方向一... 在基桩承载力检测方面,自平衡检测技术通过整合加载系统、压力监测单元及位移检测模块,实现了对桩基承载性能的高精度量化。此技术以实时、精确、简便的操作特点,在工程实践中被广泛采用。尽管如此,该技术在检测与实际工程桩受力方向一致性的模拟,以及钢筋混凝土轴心受压桩正截面受压承载力的评估上存在一定的限制。文章从自平衡检测的基本理论和目前现场实际操作出发,系统分析了其在基桩承载力检测中的优势和不足,并提出了针对性的优化方案。研究建议融合多指标综合评价、实时监控技术及大数据分析,以降低评估误差,提升检测结果的精准度。同时,提倡加强行业内技术交流和专业培训,推动技术进步。 展开更多
关键词 自平衡检测技术 原理 存在的问题 关键问题 误差处理 优化策略
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Existence of solutions and positive solutions to a fourth-order two-point BVP with second derivative 被引量:13
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作者 姚庆六 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2004年第3期104-108,共5页
Several existence theorems were established for a nonlinear fourth-order two-point boundary value problem with second derivative by using Leray-Schauder fixed point theorem, equivalent norm and technique on system of ... Several existence theorems were established for a nonlinear fourth-order two-point boundary value problem with second derivative by using Leray-Schauder fixed point theorem, equivalent norm and technique on system of integral equations. The main conditions of our results are local. In other words, the existence of the solution can be determined by considering the height of the nonlinear term on a bounded set. This class of problems usually describes the equilibrium state of an elastic beam which is simply supported at both ends. 展开更多
关键词 Nonlinear fourth-order equation Two-point boundary value problem Solution and positive solution existence Fixed point theorem
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AN EXISTENCE THEOREM OF POSITIVE SOLUTIONS FOR ELASTIC BEAM EQUATION WITH BOTH FIXED END-POINTS 被引量:12
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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.
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