长江口北槽水域的Delaunay三角剖分

为了进行长江口水动力过程等的有限元数据模拟，研究了任意平面区域的Delaunay三角剖分和基于背景网格等值线点集的新的自动生成方法：局部三角形内得到等值线、进行自动加点；改进任意平面区域的Delauay三角剖分法，与行波法结合，从区域边界向域内逐步三角化，前者简化了自动加点算法，保证新生成点均位于域内、疏密连续变化和最终网格具有良好形态，后者则统一解决了多连通、4点共圆和非凸域的自动三角剖分问题，逐步减少人为给定边界的影响，从而减少了算法的运行时间，据此开发的软件包可动态监控点，网格的生成过程，并经大量的测试、验证，应用于长江口北槽水域的自动加点和三角剖分，取得了较好的效果。     

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。     

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.     

散乱数据的三角剖分及其在快速原型制造中的应用

在考虑反求工程中通用数据分块方法的基础上,给出了一种快速、实用的任意多边形区域的自动三角剖分方法。探讨了基于三角剖分的反求工程技术与快速原型技术集成的可能性,以及直接生成快速成型机接口文件的可行性,目前这种三角剖分方法已在实际反求中取得了良好的效果。     

空间点集Voronoi图的海量构造算法及可视化技术

设计空间点集Voronoi图的增量式外存算法以及空间点集Voronoi图的任意平面可视化剖分技术,以"点-线-面-体"的空间数据结构为基础,实现在指定空间区域内生成Voronoi图的新方法.提出的算法数据结构清晰合理,数据交互方案简单有效且无内存限制,发展的可视化技术可以对空间点集Voronoi图进行任意的平面剖分,实现了三维Voronoi晶胞集合体内部结构的可视化.     

任意采空区边界信息处理与有限元网格生成

建立了任意形状采空区边界信息的管理规则，以已知漏风边界的剖分精度作为区域网格密度函数的依据，用前沿生成法的网格剖分技术自动生成Delaunay三角形单元。优先处理最长前沿边，网格节点间距密度按该边距条件边界的距离的线性函数，来控制区域内网格的尺寸变化，最终实现区域内部网格的疏密逐渐过渡，采用Laplacian优化法进行光顺处理，进一步改善了三角形质量。算例表明，可按任意采空区形状和精度自动生成三角单元，调整方便。     

关于二元三次样条函数空间的维数

研究平面上单连通闭区域Ω的任意三角剖分△上的二元样条函数空间S_3~1(△),依据一定规则对三角剖分△中个数不超过内网点个数的三角形胞腔进行HCT加密,形成新三角剖分△~*,并利用B网方法通过递推方式构造样条函数空间S_3~1(△~*)一个最小决定集,显示其维数S_3~1(△~*)具有非奇异性且等于Schumaker的维数下界.     

一种改进的螺旋边三角剖分算法

提出了一种改进的螺旋边三角剖分算法.本算法引用“自然邻近点集”的概念,以螺旋边三角剖分算法的边界环为基础向外生长三角形,以包围盒算法搜索边界点的邻近点集,估计边界点的法向量,将边界点及其邻近点集投影到切平面上并进行局部二维Delaunay三角剖分,从而确定边界点的自然邻近点集,最后将自然邻近点集以适当的方式添加到边界环上.这样,既避免了拼接问题又能搜索到自然邻近点集,三角剖分后的网格基本上接近最优Delaunay网格.实验结果表明,本算法能高效、稳定地重构出散乱数据点的三角网格.     

曲面离散数据点的三角剖分及优选探析

论述了在拟合逼近膜结构不规则区域的曲面中，如何通过自动剖分离散的数据点得到１个初始的三角形集，对初始的三角剖分进行重新组合分析，以得到适宜的三角形，从而构成１张较好的曲面。     

自动生成四边形网格的方法及其在数值模拟中的应用

采用间接方法生成四边形网格,首先利用改进的两点前沿推进法把计算区域剖分成三角形网格,然后采用插点和细分的技术生成单元全部是四边形的网格,通过边互换、删点和局部插点技术进一步光滑平顺,得到适用于数值计算的网格。剖分结果表明,该方法能够在任意二维平面区域内自动生成全四边形网格,并能生成光滑过渡的局部加密网格和贴体性较好的边界层网格。该方法具有算法简单,计算量少的特点。利用所生成的网格对计算传热学中的典型算例-方腔自然对流进行求解,计算结果与基准解吻合,网格质量能够满足数值分析计算的要求。     

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