平面有分枝圆模式的Andreev-Thurston定理

对于给定的一个拓扑圆盘的有限加权三角剖分,证明了实现它的平面有分枝圆模式的存在性和惟一性定理.根据单叶圆模式的存在性,通过引进一种算法来构造所要求的圆模式,然后证明这种算法是行之有效的而得到其存在性部分;根据圆模式的圆半径比率函数的极大值原理,推出其惟一性.     

关于高斯最小值猜测的一个注记

高斯分布又叫正态分布,在数学、统计学、物理及工程等领域具有非常重要的作用,人们熟知的中心极限定理也彰显了它的特殊性。跟高斯分布相关的不等式与许多领域密切相关,吸引了众多学者的关注。一个著名的例子是“高斯最小值猜测”,该猜测说的是：如果$n\geq 2$, $(X_i,1\leq i\leq n)$为中心化高斯随机向量,则不等式 $E\left(\min_{1\leq i\leq n}|X_i|\right)\geq E\left(\min_{1\leq i\leq n}|Y_i|\right)$成立,其中$Y_1,\ldots,Y_n$为相互独立的中心化高斯随机向量并且满足$E(X_i^2)=E(Y_i^2)$, $i=1,\ldots,n$. 在这篇注记里,我们证明该猜测成立当且仅当 $n=2$.     

一个积分算子的单叶性

引入了一个定义在单位圆$\mathcal{U}=\{z\in\mathbb{C}:|z|1 \}$内规范化的解析函数类$\mathscr{A}$上的积分算子$J_{\gamma_1,\cdots,\gamma_n,\beta}(z)$, 利用著名的Becker单叶性判别法, Schwarz引理和Caratheodory不等式, 得到了这个积分算子在单位圆内单叶的3个充分条件. 即当$f_{j}(z)(j=1,2,\cdots,n)$及参数$\gamma_{1},\cdots,\gamma_{n},\beta$满足一定条件时, 积分算子$J_{\gamma_1,\cdots,\gamma_n,\beta}(z)$ 在单位圆内是单叶的.     

关于两类平面图及相关图的L(2,1)-标号问题

图G的L( 2 ,1) 标号是一个从顶点集V(G)到非负整数集的函数f(x) ,使得若d(x ,y) =1,则 |f(x) -f(y) | 2 ;若d(x ,y) =2 ,则 |f(x) -f(y) | 1 图G的L( 2 ,1)标号数λ(G)是使得G有max{f(v) :v∈V(G) } =k的L( 2 ,1)标号中的最小数k Griggs和Yeh猜想对最大度为Δ的一般图G ,有λ(G) Δ2 证明了对平面三角剖分图、立体四面体剖分图、平面近四边形剖分图 ,有上述猜想成立     

平面点线集三角剖分的扫描算法

提出计算平面点线集三角剖分的一种算法.该算法是利用平面扫描的思想,当扫描线达到事件点时,处理事件点,即将事件点与已被扫描的某些点连接,这样便将已扫描的区域三角剖分.当扫描线达到最左边的事件点时,处理该事件点,就完成了平面点线集的三角剖分.证明了算法的时间复杂性为O(NlbN),其中N是点线集中点的数目与线段端点数之和.     

Banach空间中含$(\emph{\textbf{H}},\bm\phi)$-$\bm\eta$-单调算子的变分包含组

在实的一致光滑Banach空间中, 引入一类新的含$(H,\phi)$-$\eta$-单调算子的变分包含组. 利用$(H,\phi)$-$\eta$-单调算子的近似映射技巧, 证明了此类新的变分包含组解的存在性与唯一性, 并构造了逼近此类变分包含组解 的迭代算法; 讨论了由此迭代算法生成的迭代序列的收敛性. 所得结果推广与改进了文献中的一些主要结果.     

油藏任意约束平面域PEBI网格的生成算法

针对油藏任意约束平面多边形区城提出了一种实用的局部正交化网格(PEBI)生成葬法。首先对边界顶点和区域内部散乱点按扫描方式排序,依次扫描各点生成新的三角形,再扫描新生成的三角形中不满足Delaunay准则的三角形,进而不断的处理这些不合理三角形最终完成整个区域的三角网格化,最后连接每个三角形的外接圈固心生成PEBI网格。剖分过程中采用了弹性平清和对角线交换优化方法,很容易实现局部区域的最优化剖分。通过平面映射法就可以应用到油藏的三维PEBI网格剖分,因此本算法具有很好的可操作性和实用性。     

边替换图的邻和可区别全染色

考虑图的邻和可区别全染色问题及其相关的1-2猜想.首先,利用独立消圈集法得到剖分图S(G)和三角扩展图R(G)的邻和可区别全色数;其次,当G为任意简单连通图且T为给定的特殊图时,证明边替换图G[T]满足1-2猜想.     

平面三角剖分图的L(2,1)标号

图G的L（2，1）标号是从一个顶点集V（G）到非负整数集的函数f(x)，使得若d(x,y)＝１，则|f(x)-f(y)|≥２；若d(x,y)=2，则|f(x)-f(y)|≥1。图G的L（2，1）标号数λ（G）是使得G有max{f(v):v∈V（G）}=k的L（2，1）标号中的最小数k。本文证明了对最大度数为△的一般平面三角剖分图G，有λ（G）≤△^2-△；当G的直径大于2时，有λ（G）≤△^2-△。     

关于适约三角剖分计数的一点注记

一个有根平面地图是近-三角的,如果其所有的非根面在拓扑意义下均为三角形.进而,如果根面也是一个三角形,则称这个地图为一个三角剖分.本文所讨论的(近-)三角剖分均为无环的,不难看出,无环的三角剖分也是不可分离的.如果它的根面次是2,则称它是2-边界的.如果一个2-边界近-三角剖分无内部边平行于根边(即与根边构成重边),则称其为约化的.一个三角剖分叫做适约的,如果它无环且内部不含有平行于根边的边.     

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.     

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     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the