旅行售货问题的一个多项式近似算法

§1 引言旅行售货员问题(traveling salesman problem)(TSP)是运筹学中的著名问题。 TSP的图论提法如下:给定一个完全图K_n,对K_n中每条边e,赋于一个非负整数权w(e),得完全赋权图[K_n~(?),w(e)],求出[K_n,w(e)]具有最小权的哈密顿圈。 TSP是一个著名的世界难题,许多年以来,世界上很多数学家付出了巨大的努力去寻找它的有效算法,但收获不大.直到七十年代初期,S. A. Cook和R. M. Karp建立了MP     

故障3-元n-立方体的哈密顿圈嵌入

哈密顿圈嵌入问题是研究互连网络并行计算中最重要问题之一.在文章中,我们考虑带故障点的3-元n-立方网络Qn3的哈密顿圈嵌入问题并得到如下结果.给定一个具有至多2n-2个故障点的集合F,对Qn3-F中任意边,除一种特殊情况外,Qn3-F中都有一个哈密顿圈包含这条边,即Qn3-F是几乎-边哈密顿的.     

含空洞的马步型哈密顿圈探索

通过搜索某些特殊的较小马步遍历,将其按照一元旋转与二元支撑两种组合模型构建成含空洞的马步型哈密顿圈,拓广了哈密顿圈图论课题的研究范围.     

均衡二分图中存在哈密顿因子的条件

研究了在均衡二分图中包含给定哈密顿圈的[k,k+1]因子的存在性问题.根据图论中因子和临界图理论,并结合代数知识,针对均衡二分图,研究图的阶数,顶点的度和因子之间的关系,分情况讨论,通过对均衡二分图的临界条件的限制,给出均衡二分图中存在包含给定的哈密顿圈的[k,k+1]因子的充分条件.该条件在很大程度上改进了已有的包含哈密顿圈的度条件,进一步完善了包含哈密顿圈的因子理论.算例表明所用方法的有效性,所得结论的正确性.     

与Catalan数相关的累计计数问题的探讨

研究了与Catalan数相关的累计计数问题,在给出与Catalan数相关的二元累计计数问题一般性结论的基础上,主要讨论了与Catalan数相关的三元累计计数问题,并得到相应的结论.     

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.     

广义容斥原理的应用

利用二项式反演公式以及文献[1]中的广义容斥原理解决了一个组合计数问题,获得了该计数问题的若干显计数公式.     

有限交换p-群中加性码的计数

解决了有限交换p-群中加性码的两类计数问题,第一类计数问题是指求任意给定的有限交换p-群中任意类型码的数目,第二类计数问题是指求包含同一类型码的有限交换p-群的数目以及它们分别所含有的该类型码的数目.     

k-连通图中最长圈上可收缩边的数目

给出了k-连通图中最长圈上的可收缩边的数目,得到如下结果:任意断片的阶至少为「k/2+1 的k-连通图中最长圈上至少有3 条可收缩边;更进一步,若该k-连通图中存在哈密顿圈,则哈密顿圈上至少有6 条可收缩边。     

范更华教授荣获2005年度国家自然科学奖二等奖──“哈密顿圈及圈覆盖理论”

在2006年1月9日召开的全国科学技术大会上,我校副校长范更华教授的科研成果“哈密顿圈及圈覆盖理论”荣获2005年度国家自然科学奖二等奖。这是我省省属高校在该奖项上零的突破,也是今年我省唯一获奖项目。现实世界中许多问题的数学抽象形式可以用图来描述。对图的研究形成了一个专门的数学分支：图论。过图中每点恰好一次的固称为哈密顿圈。哈密顿圈问题是图论最古老的研究课题之一,亦是至今未解决的世界难题。范更华教授的获奖项目为这一问题的研究开辟了一条新的途径,他证明：若图中每对距离为2的点中有一点的度数至少是图的点数的一半,则该图存在哈密顿圈。此成果引发了大量后续研究     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that