巧用倒序逆推法求值

在数学运算及推理过程中，如果采用由条件到结论直接的运算有可能出现运算量大，推理论证陷入死角，导致出现错误或望题兴叹，此时换一种运算方式进行倒序逆推或许问题变得简单明了．本文结合实例浅谈倒序逆推法求值运算．     

巧用倒序逆推法求值

在数学运算及推理过程中,如果采用由条件到结论直接的运算有可能出现运算量大,推理论证陷入死角,导致出现错误或望题兴叹,此时换一种运算方式进行倒序逆推或许问题变得简单明了.本文结合实例浅谈倒序逆推法求值运算.     

美元危机还能避免吗？

对于美元,未来真正的考验是联储将在何时加息—如同油漆工把自己刷进了没有退路的死角,欲逃无路,并由此招致了轰动性的＂集体围观＂。     

3-齐次群与旗传递5-（v，k，3）设计

旗传递t-设计的分类是代数组合学的一个重要课题．本文主要讨论了旗传递5-（v,k,3）设计．由P．J．Cameron和C．E．Praeger的结论可知,此时设计的自同构群是3-齐次群．本文利用3-齐次群的分类,证明了设计的自同构群不能是仿射型群．     

关于一类常微分方程亚纯解的存在性

本文运用Ｎｅｖａｎｌｉｎｎａ值分布理论，解决了具一项控制系数Ｐｎ或Ｐｏ的微分方程亚纯解的存在性与可能的个数问题．同时举例说明所给结果是精确的．本文完善了Ｇ．Ｇｕｎｄｅｒｓｅｎ和Ｉ．Ｌａｉｎｅ等人的工作．     

一类非线性Chandrasekhar H-方程的正解

本文通过研究一类非线性算子方程解的存在性，建立了一类出现在辐传理论与气体动力学中的非线性ＣｈａｎｄｒａｓｅｋｈａｒＨ－方程正解或负解的存在性定理．本文的几个定理包含或改进了ＲｉｃｈａｒｄＷ．Ｌｅｇｇｅｔｔ和Ｃ．Ａ．Ｓｔｕａｒｔ等人的一些已知结果．     

高等学校医院管理的分析研究

本文根据高等学校医院的实际工作情况，进行系统分析，包括目标分解、因果分析和措施探索，研究如何提高管理水平．充分发挥校医院的作用．本文的分析可供企事业单位的职工医院参考．     

非线性积分微分方程的稳定性

本文研究一类非线性积分微分方程的稳定性问题．给出了简洁、实用的稳定性新准则．文末例子说明了本文结果的优越性。     

房产需求量中的若干数学模型和研究

本文是继2006年研究项目“上海市基础房价走势”后的又一后续课题．其宗旨是研究、预测2007年上海市住宅需求量．基于易居（中国）房地产研究院所提供的数据，本文在数据相关性分析基础上，建立了二个预测模型，每个模型分别用2种方法得出结果，以便验证并消除系统误差．模型一：回归模型．分别利用主成分分析基础上的回归以及逐步回归法．模型二：核密度函数模型．通过核估计以及核回归，进行预测．本文模型具有一定的可操作性，使用简便．所得结果得到有关专家的论证和确认．     

关于矩阵特征值问题向后误差分析的注记

本文研究实矩阵关于复近似特征对的范数型向后误差．在复扰动情形,这个问题已被Higham 等学者解决．本文研究实扰动情形．结果表明,通常情况下,两种情形差别不大,但在某些情形,二者可以相差很大．作为推广,我们还讨论了矩阵多项式的相应问题．文中的一个结果部分地解决了D．J．Higham和N．J．Higham 1999年提出的一个待解决的问题．     

关于稳态反应扩散对流方程的死核问题

本文研究带参数λ的稳态反应扩散对流方程△u=λf(u,Du)的死核问题,证明了当函数f满足一定的条件时,对每个有界光滑区域Ω存在相应的正数λ(Ω)使当λ>λ(Ω)时该方程在边值条件u=1下的非负解有死核,并讨论了死核随λ的变化情况。     

带梯度项的半线性椭圆与抛物型方程解的死核问题

带梯度项的半线性椭圆与抛物型方程解的死核问题程尚斌（兰州大学数学系，兰州７３００００）兰州大学科研基金资助课题．１９９１年３月１１日收到，１９９１年１１月２３日收到修改压缩稿．一、引言１９８４年，人们发现对一定类型的半线性椭圆与抛物型方程，它们具非零...     

A Steady-State Diffusion Problem with Fractional Power Absorption Rate

The steady-state problem of a gas diffusing through a nonlinearlyabsorbing medium with mass-transfer resistance at the boundaryis investigated. When the rate of absorption is proportionalto a fractional power of the concentration, it is possible forthe concentration to vanish in a part of the medium known asthe dead core. Estimates are obtained for the location and shapeof the dead core, particularly in the asymptotic regime of largeabsorption. These results both complement and extend to higherdimensions the two-dimensional results of Friedman and Phillips(1984).     

Qualitative properties for solutions of singular elliptic inequalities on complete manifolds

We establish several qualitative properties for solutions of singular quasilinear elliptic differential inequalities on complete Riemannian manifolds, such as the validity of the compact support principle, of the strong maximum principle, existence of solutions to exterior Dirichlet problems, existence of dead core solutions.     

The finite element approximation of a coupled reaction-diffusion problem with non-Lipschitz nonlinearities

Summary. A coupled semilinear elliptic problem modelling an irreversible, isothermal chemical reaction is introduced, and discretised using the usual piecewise linear Galerkin finite element approximation. An interesting feature of the problem is that a reaction order of less than one gives rise to a "dead core" region. Initially, one reactant is assumed to be acting as a catalyst and is kept constant. It is shown that error bounds previously obtained for a scheme involving numerical integration can be improved upon by considering a quadratic regularisation of the nonlinear term. This technique is then applied to the full coupled problem, and optimal and error bounds are proved in the absence of quadrature. For a scheme involving numerical integration, bounds similar to those obtained for the catalyst problem are shown to hold. Received May 25, 1993 / Revised version received July 5, 1994     

Dead cores of singular Dirichlet boundary value problems with ϕ-Laplacian

The paper discusses the existence of positive solutions, dead core solutions and pseudodead core solutions of the singular Dirichlet problem (ϕ(u′))′ = λf(t, u, u′), u(0) = u(T) = A. Here λ is the positive parameter, A > 0, f is singular at the value 0 of its first phase variable and may be singular at the value A of its first and at the value 0 of its second phase variable. This work was supported by grant no. A100190703 of the Grant Agency of the Academy of Sciences of the Czech Republic and by the Council of Czech Government MSM 6198959214.     

Boundary displacements in membranes of revolution under symmetrical loads

Summary Boundary displacements in a large variety of membranes of revolution under live and dead loads are explicitely given. The boundary rotation is proved to be independent of the meridional shape for the dead load and identically zero for live loads under conditions often encountered in structural domes. To Mauro Picone on his 70^th birth day.     

Dead ends in misère play: The misère monoid of canonical numbers

We find the misère monoids of normal-play canonical-form integer and non-integer numbers. These come as consequences of more general results for the universe of dead-ending games. Left and right ends have previously been defined as games in which Left or Right, respectively, have no moves; here we define a dead left (right) end to be a left (right) end whose options are all left (right) ends, and we define a dead-ending game to be one in which all end followers are dead. We find the monoids and partial orders of dead ends, integers, and all numbers, and construct an infinite family of games that are equivalent to zero in the dead-ending universe.     

有限组两个完全同向单形的广义加权度量加

利用广义Menger度量嵌入定理,推广了关于两组两个完全同向n维单形"广义度量加"的概念,提出了关于有限组两个完全同向n维单形的"广义加权度量加"的概念,并运用距离几何理论同矩阵不等式结合的方法,证明了几个涉及"广义加权度量加"的几何不等式,它们进一步推广了杨路和张景中关于Alexander猜想的结果,这些结论蕴含近期诸多文献的主要结果.