二阶线性脉冲微分方程的振动性

研究一类二阶线性脉冲微分方程解的振动性,揭示了此类方程与相应的非脉冲方程在振动性方面的联系．     

一类二阶线性微分方程的振动性与非振动性

通过推广文献[1]的结论,得到了关于二阶微分方程y"+q(t)y=0的新的振动性与非振动性定理,其中对于固定的上可积.     

具变号系数的一阶线性差分方程的解的渐近性与振动性

讨论具变号系数的一阶线性差分方程Δx(n) ∑mj=1pj(n)x(n-τj) =0的解的渐近线和振动性 ,获得了方程振动的两个充分条件 ,同时得到了其所有非振动解趋于零的一个充分条件 .     

一阶中立型微分方程的振动性及其非振动解的渐近性

文章给出了一阶中立型微分方程振动的充分条件，同时又给出了该方程非振动解的存在性与渐近性的判据。     

二阶微分方程振动与非振动的充分条件

研究了一类二阶微分方程的振动性质，利用方程的系数满足的微分不等式来判断方程的振动性.     

具有分段常数变元的一阶线性微分方程

本文讨论一阶具有分段常数变元线性微分方程的振动性,得到了三个振动性定理。     

二阶非线性差分方程的振动准则

研究了一类二阶非线性差分方程解的振动性，给出了这类方程的振动准则，产对主要结果举例说明。     

一阶具正负系数的中立型微分方程的振动性

先给出了一类一阶非线性时滞微分方程振动的充要条件,然后应用这个结果研究了一类非线性一阶中立型微分方程的振动性,所得结果推广了这方面的原有结果。     

二阶中立型差分方程解的振动性(Ⅱ)

该文对某类二阶非线性中立型差分方程解的振动性进行了讨论,改变了[8]中原有方程的条件,因而完善了此类二阶中立型差分方程解的振动性结果。     

二阶线性微分系统解的振动比较定理

通过建立两个微分恒等式,研究了二阶线性微分系统预备解的振动性,得到两个新的振动比较定理。     

关于集合的平移及其性质

本文主要讨论平移集合的最基本性质,即集合的并,合的平移性,集合的基数的平移性,集合的有界性的平移性,极值性的平移性,可数集合的平移性等问题。     

Disillusionment of the American Dream——On An American Tragedy

Theodore Dreiser is now regarded as one of the pre-eminent American realistic novelists of the first half of the twentieth century.an anatomist of the American Dream.In his great work An American Tragedy,Dreis- er exposes and criticizes mercilessly the corruption and black side of American society.The disillusionment of the American Dream is an important theme of the fiction.This paper illustrates "An American Tragedy" is the re- flection of disillusionment of the American Dream in the perspectives of the tragedy of a mortal,the tragedy of American society,and the tragedy of the American Dream.     

论马克思唯物史观的形成

唯物史观是马克思一生中的两个伟大发现之一。唯物史观的创立实现了社会历史观的伟大变革 ,标志着马克思主义哲学的诞生。唯物史观的形成过程就是马克思不断揭示生产力和生产关系辩证运动规律的过程 ,也是马克思不断肃清费尔巴哈人本主义的影响 ,走向历史唯物主义的过程。马克思的唯物史观是一种崭新的社会历史观 ,它根本不同于费尔巴哈人本主义的历史观。学习马克思的早期著作 ,探讨唯物史观的形成 ,对于我国当前的改革开放和社会主义现代化建设 ,有着重大而深远的理论意义和实践意义     

What Education do you Miss by Going to School? Children's 'Coming-to-Knowing' About Science and Their Environment

Starting from Whitehead's notions of education as "the art of the utilisation of knowledge" and his rationale for eradicating "the fatal disconnection of subjects which kills the vitality of the modern curriculum," the article explores how these ideas relate to the current political realities of primary education in the United Kingdom and elsewhere. This is exemplified through a focus on learning about one's environment and the consequent tension between direct perception through non-school activities and the teaching of ideas via the formal school curriculum. A resolution is proposed which involves considering the learner's perspective, and the implications for teachers in terms of 'letting pupils in' to the teachers' own learning and their awareness of a plurality of ways of knowing.     

Effects of continuous casting mould fluxes on reducing longitudinal and star cracks on a slab surface

1.IntroductionAstothecurrenttechnologyofcontinuouscastingofsteel,itisanemergencyformouldfluxestoharmonizetheconflictsbetweenheattransferandlubricationforslabcasting.Whenstructuralsteelwhosemassfractionofcarbonwcis0.09%to0.15%andhighstrengthlowalloysteel(HSLA)whosewcis0.14%to0.25%arecontinuouslycast,itisnecessarytocontroltheheatfluxfromtheslabshelltothecoppermouldnottoexceed1.7?06W/m2becauseofthebigandcoarseausteniticcrystalsintheinitialsolidifiedslabshell[1].Otherwise,longitudinalcrackstendt…     

Kierkegaardian Implications of Punishment, Guilt, and Forgiveness for Education

Students have to be punished if they have made a serious transgression. Avoidance of punishment will lead to serious complications. But punishment is inseparably linked with guilt and forgiveness. The inability of individuals to forgive themselves was regarded by Kierkegaard to be an emanation of individual false pride, a kind of vanity. This type of despair, a psychological and spiritual disorder, is a serious and debilitating problem. The inability to escape this despair of forgiveness can lead to a loss of genuine humanness. Unchecked, this despair can lead to unrelatedness of self to itself and fear of the possibility of freedom. Thus the self-knowledge attainable in despair over the forgiveness of an offense would lead to what we would call a successful rehabilitation of the individual and his or her conjunct reintegration into society. Kierkegaard's ideas on punishment are interesting — historically and philosophically speaking — because they represent a softening of a harsh view of punishment by stressing the humanizing aspects of guilt and forgiveness.     

弗洛伊德“性力升华说”探微

弗洛伊德坚持“性欲乃是人类取得的一切成就的源泉”，认为“本能的升华是最引人注目的文化发展的特征；正是由于升华，高级的心智活动、科学活动、艺术活动或思想活动才成为可能。”人们对此很有异议。其实，弗洛伊德是在对“性”的最广泛意义的理解基础上创建他的“动力心理学”的，他试图从他对人的个体心理理解的立场出发，来解释人类的全部历史、全部事件和社会生活的结构，并以此建立一整套关于人类精神生活规律的学说和理论。深入探寻弗洛伊德性学说的底蕴，澄清他的“性力”、“原欲”概念的内涵，真正领悟其“升华”思想的真谛，才有可能拓宽我们的视野，深化对复杂纷繁的人的精神世界的研究。     

“存在”之“光”——海德格尔美论研究

海德格尔认为"美"源自审美状态,而审美状态并非是主体的某种精神状态,而是"存在"的本然状态。美是存在者自身的显现,"存在"即是美的本质,也是美的功用,美不是显现的结果,而是"显一现"这个动态过程。存在之显现之所以美是因为,人无法在流变的世界中领会与观照存在之本质,存在必然在生活的日常状态中被遗忘,只有打破了这种遗忘状态,人才能获得真正的自由,获得存在之澄明,这种获得存在之澄明状态过程,就是获得美的本质与本源的过程,美就是存在者的澄明之光,是存在之光。     

从文明无知、文明冲突到文明交往、文明和谐--对学术界三种文明观的基本述评

文明是决定和影响人类活动的长期的基本因素。冷战结束后，特别是随着“文明冲突论”的提出，各种文明观的讨论逐渐演化成文明学的各种派系。当前主要有三种文明观：文明冲突论、文明对话论、文明交往论。在处理国与国关系的实践中应承认并维护文明的多样性。文明发展的趋势是文明和谐和文明相处。人类真正的危险在于各个民族、国家间文明的互不相融，以及由此导致的误解、紧张、冲突乃至战争。世界的持久和平与持续发展有赖于人与人之间、民族与民族之间、国家与国家之间文明的对话、沟通和理解，有赖于文明间的和谐，共同发展。     

团图为数的图中的闭团贯数

Given a graph G,a subgraph C is called a clique of G if C is a complete subgraph of G maximal under inclusion and |C|≥2. A clique-transversal set S of G is a set of vertices of G such that S meets all cliques of G. The clique-transversal number, denoted as TC (G), is the minimum cardinality of a clique-transversal set in G. The clique-graph of G, denoted as K (G), is the graph obtained by taking the cliques of G as vertices, and two vertices are adjacent if and only if the corresponding cliques in G have nonempty intersection. Let F be a class of graphs G such that F={G|K(G) is a tree}. In this paper the graphs in F having independent clique-transversal sets are shown and thus TC (G)/|G|≤1/2 for all G ∈ F.