一类限位排列的计数

限位排列是组合计数的一个重要研究内容,应用容斥原理等组合分析技巧研究一类限位排列的计数问题,具体给出了计算此类限位排列数的计数方法和计数公式,拓广了已有文献的研究结果。最后,提出有待进一步研究的限位排列的计数问题。     

车多项式在解决禁位排列问题中的应用

禁位排列是组合数学中的一个重要研究方向。而利用车多项式解决禁位排列是一种极好的解决方法．本文对于重排问题的计数公式用禁位排列的知识给予了证明，并对一类特殊禁位排列给予了相应的计数公式．     

伯恩赛德引理的推广及应用

对Buruside引理做了进一步推广,对一类计数问题进行了分析,研究了一种特殊的计数问题,即在不太规则不太对称的情况下的计数问题,并得到了在此情况下的计数公式.     

《组合数学》教学指导

本文主要从组合数学的研究方法及主要内容来介绍组合数学的主要知识点。它包括排列组合的基本计数方法，组合恒等式的证明技巧中常用的公式及其技巧，母函数求特殊容量限制的排列和组合问题，以及利用间接方法来求解计数问题的容斥原理，解决特殊计数的整数分拆，以及如何建立递归关系，用递归关系求母函数的方法，解决存在问题的鸽巢原理及Ramsey的问题，还有集合上等价类计数问题的Polya计数定理应用。     

Kaplansky计数命题的拓广及应用

应用组合分析技巧,给出基于线排列与环形排列情形下的经典的Kaplansky计数命题的拓广情形,得到了两个推广后的新的Kaplansky计数命题.通过推广Ménage计数问题以及组合恒等式的证明,所得结果拓展了已有文献的研究结果.     

一类排列问题的计数

给出一类排列问题的计数公式．     

一致二部竞赛图的计数

研究了一种局部有序－无序排列的计数问题和一致二部竞赛图的某些性质。通过讨论，解决了标定一致二部竞赛图的计数问题，并获得了一个简明计算公式。     

容斥原理在错位排列中的应用

介绍了容斥原理求计数的基本定理，并给予了证明，在容斥原理应用中推导出求解绝对错位排列和相对禁止位子排列的计数问题的解法。     

一致二部竞赛图的计数

研究了一种局部有序－无序排列的计数问题和一致二部竞赛图的某些性质，通过讨论，解决了标定一致二部竞赛图的计数问题，并获得了一个简明计算公式。     

正六面体的旋转群导出的点边面置换群的轮换指标

“计数问题”是组合数学中的一个重要问题,文章利用Burnside引理,Po lya计数定理及某些群论知识,导出了正六面体点边面的置换群的轮换指标表示,很好地解决了某些特定的计数问题。     

企业产权的动态安排及企业剩余分配的均衡分析

按照科斯和阿尔钦等人对公司的定义,企业是一个由各种要素所有者形成的合约.企业的要素从大的方面分为人力资本和非人力资本,要素所有者在形成合约时,面临着产权的重新安排,这一安排的前提是双方收益的最大化.企业同时又是区别于其他一次性交易的特殊合约,因此它的产权安排是动态的,而企业剩余的分配也是动态的.正是从这一角度出发,通过对产权和企业剩余的安排过程进行分析,得出均衡分配的结论.     

地下含水层热储井位置选择和布置

地下含水层热储开发技术面临一系列问题,寻找适合热储用的含水层和合理布置热储井是解决问题的第一步.综合考虑含水层的地质结构特征,适合热储的含水层应该是承压含水层,热储应该采用同层方式.单个热储井的影响半径可以通过热平衡和热扩散原理求得.合理布置热储井间的相对位置,可以有效抵消原有地下水的流动以及渗流系数不一致的影响.利用井之间的渗流耦合作用,在热储井之间布置调节井,主动控制热储水的波及范围,可以实现热储井布置的相对"紧凑".     

Identical V beta T-cell receptor genes used in alloreactive cytotoxic and antigen plus I-A specific helper T cells

T lymphocytes involved in the cellular immune response carry cell-surface receptors responsible for antigen and self recognition. This T-cell receptor molecule is a heterodimeric protein consisting of disulphide-linked alpha- and beta-chains with variable (V) and constant (C) regions. Several complementary DNA and genomic DNA clones have been isolated and characterized. These analyses showed that the genomic arrangement and rearrangement of T-cell receptor genes using VT, diversity (DT), joining (JT) and CT gene segments is very similar to the structure of the known immunoglobulin genes. We have isolated two cDNA clones from an allospecific cytotoxic T cell, one of which shows a productive V beta-J beta-C beta 1 rearrangement without an intervening D beta segment. This V beta gene segment is identical to the V beta gene expressed in a helper T-cell clone specific for chicken red blood cells and H-21. The other clone carries the C beta 2 gene of the T-cell receptor, but the C beta 2 sequence is preceded by a DNA sequence that does not show any similarity to V beta or J beta sequences.     

一类非线性奇摄动边值问题的渐近解

利用匹配渐近展开法,研究了一类带参数的非线性奇摄动边值问题.首先找到满足退化方程的外部解,然后根据参数k的变化分五种情况找到用特殊函数表示的内层解,得到了该问题具有左边界层、右边界层或内部层之一的结论(其中左、右边界层又各分为两种情况).最后通过匹配原则,将内外展开式进行匹配给出了该问题的一致有效的零阶渐近展开式.     

Complexity of human T-cell antigen receptor beta-chain constant- and variable-region genes

Immune systems of vertebrates function via two types of effector cells, B and T cells, which are capable of antigen-specific recognition. The immunoglobulins, which serve as antigen receptors on B cells, have been well characterized with respect to gene structure, unlike the T-cell receptors. Recently, cDNA clones thought to correspond to the beta-chain locus of the human and mouse T-cell receptor have been described. The presumptive beta-chain clones detect gene rearrangement specifically in T-cell DNA and show homology with immunoglobulin light chains. The similarity of the T-cell beta-chain gene system to the immunoglobulin genes has been further demonstrated by the recent observation of variable- and constant-region gene segments as well as joining segments and putative diversity segments. We report here the characterization of cDNA and genomic clones encoding human T-cell receptor beta-chain genes. There are two constant-region genes (C beta 1 and C beta 2), each capable of rearrangement and expression as RNA. The gene arrangement, analogous to that of mouse beta-chain genes, shows strong evolutionary conservation of the dual C beta gene system in these two species.     

圆周上Markov映射逆极限空间的同胚问题

证明了圆周上两个关于两组固定分点的Markov映射列在相同下标的两个约束映射总是关于两组分点的固定次序Markov同型的条件下生成同胚的逆极限空间．特别考虑了把相邻分点之间的弧映满圆周(并环绕圆周若干次)或具有无穷个水平区问的Markov映射．     

一种动态的时延约束费用优化多播路由算法

对动态环境下满足时延约束且费用最优的多播路由算法进行了研究.改进了一种触发重组算法,该算法根据一个区域内的节点加入或退出次数来确定对多播树的损害程度,若达到所给定平衡因子的值则触发重组.仿真表明,该算法具有较好的性能,能满足某些特殊的场合的要求.     

A novel method to improve the performance of heatexchanger——Temperaturefields coordination of fluids

The methods to enhance the heat transfer in heat exchanger may be classified into two levels: one is to improve the heat transfer coefficient; the other is to upgrade the whole arrangement of the heat exchangers. For the second level, the performance of heat exchanger can be upgraded by increasing the coordination degree between the temperature fields of cold and hot fluids. When the temperature distributions are similar to each other, the temperature difference field (TDF) is more uniform, which means that the temperature fields are more coordinated with each other. For the cross-flow heat exchanger, rearrangement of the heat exchange surface area should improve the heat transfer effectiveness, which is even equal to that of the counter-flow heat exchanger when the surface area is reassigned optimally. For the multi-stream heat exchanger, the thermal performance is also dependent on the uniformity of the TDF, and the parallel-flow arrangement may achieve higher heat exchange effectiveness than the counter-flow arrangement, which indicates that the performance of heat exchanger depends on the coordination degree of temperature fields instead of the flow arrangement.     

A novel method to improve the performance of heat exchanger——Temperature fields coordination of fluids

The methods to enhance the heat transfer in heat exchanger may be classified into two levels: one is to improve the heat transfer coefficient; the other is to upgrade the whole arrangement of the heat exchangers. For the second level, the performance of heat exchanger can be upgraded by increasing the coordination degree between the temperature fields of cold and hot fluids. When the temperature distributions are similar to each other, the temperature difference field (TDF) is more uniform, which means that the temperature fields are more coordinated with each other. For the cross-flow heat exchanger, rearrangement of the heat exchange surface area should improve the heat transfer effectiveness, which is even equal to that of the counter-flow heat exchanger when the surface area is reassigned optimally. For the multi-stream heat exchanger, the thermal performance is also dependent on the uniformity of the TDF, and the parallel-flow arrangement may achieve higher heat exchange effectiveness than the counter-flow arrangement, which indicates that the performance of heat exchanger depends on the coordination degree of temperature fields instead of the flow arrangement.     

粘弹性薄板弯曲问题的描述及其解法

通过引进“结构”函数，建立了各向异性粘弹性薄板准静态弯曲问题的边值问题，在各向同性情况下，讨论了变量分离的条件，针对两类特殊的边值问题，提出了相应的解法，并给出了两个具体问题的解析解。