一类射影柱面方程的求法

文章主要讨论了空间曲线在一般平面上的射影柱面方程的求法。     

广义柱体分析法在阅读和绘制机械图中的应用

介绍了用于阅读和绘制机件视图的一种方法—广义柱体分析法，给出了广义柱体的概念，分析了它的投影特点，通过实例说明了广义柱体分析法的作图方法及应用范围。     

一组新的柱面全景图投影公式及其交互浏览器的Java Applet实现算法

事先将在同一视点环绕拍摄的多幅部分重叠的图像正投影合成为一幅无缝的图像文件一柱面全景图．它代表在拍摄点看到的周围360度视角的三维场景．在浏览时将用户观察的相应部分实时进行反投影为平面图像，然后投影到屏幕上．随着视角的改变．就可实现虚拟场景的漫游．柱面全景图的环视浏览具有很好的真实感和沉浸感．对计算机的硬件要求不高．本文详细介绍了这种全景图浏览器的实现原理．给出了一组全新且简便的投影与反投影公式，并在此基础上开发了交互式的Java Applet柱面全景图浏览器．最后给出了关键的JAVA代码．     

统一框架下的柱面和锥面教学

在直纹曲面的框架下统一了柱面、锥面方程的求法,统一了柱面、锥面判别定理的证明方法,统一了二次柱面、锥面的判别形式,从而把柱面和锥面放在统一的框架下进行教学。     

一种快速的柱面全景图生成算法

全景图是构造虚拟环境的基本要素之一,本文提出了一种快速的柱面全景图的绘制算法。首先对原始图像进行柱面投影。然后通过对图像重叠部分的对应特征区域进行匹配和拼接来实现图像的无缝拼接。实验表明该算法运算量较小,能有效、快速地生成柱面全景图。     

基于极小扩展原理的表现外延

给出因素空间中基于极小扩展原理的外延与表现外延,并研究表现外延的投影与柱体扩张的若干性质.     

点到平面距离的公式的一种简捷求法

设已知一平面π,其方程为：Ax＋By＋Cz＋D＝0,平面外一已知点M0（x0、y0、z0）,则点M0到平面π之间的距离公式为：现行《高等数学》教材中关于点到平面距离的公式有两种求法：文献[1]给出的求法为（简称“求法一”）：从点M0作平面π的垂线（图1）,设垂足为Q（x2、y2、z2）,则向量M0Q与平面π的法向量平行,故垂线M0Q的方程为：图1关于点到平面距离的公式的求法一文献[2]、[3]、[4]等给出的求法均为（简称“求法二’）：在平面。内任取一点风（xl,川,11）,过M。作平面。的法向量n＝NM（图2）,则点MO到平面知的距离为：臼2关…     

一类柱面方程的求法

本文提供了准线为任意空间曲线,母线平行于坐标轴的一类柱面方程的求法并进行了结论的适当推广,能帮助学生快捷、准确解决柱面方程问题,对于教师教学和学生学习具有一定的指导意义。     

椭圆柱体在平面上摆动固有频率的近似计算方法

本文给出了匀质椭圆柱体在平面上作无滑动的微幅摆动之固有频率的两种近似计算方法,得到两个固有频率的计算公式。计算结果与实验所得数据吻合良好。其中第二法引入曲率圆的想法,可用以计算具复杂轮廓的匀质柱体在平面上作微幅摆动的固有频率,方法简单。     

曲面上两相离曲线段的光滑过渡曲线

光滑曲面上的曲线造型是CAGD的一个新的研究方向,本文提出了曲面上两相离曲线的光滑过渡曲线的构造方法.基本思想是:将两分离曲线段的端点及切向量、曲率向量投影到平面,在平面上构造插值于投影点及切向量、曲率向量的G1和G2连续插值曲线,该插值曲线的投影柱面与曲面的交线就是连接两给定曲线段的光滑曲线.图例显示该方法具有满意的效果.     

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.     

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     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with     

Journal of Donghua University ( English Edition) Contents of Volume 31

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Brief Introduction to “Journal of Jilin University( Science Edition) ”

<正>"Journal of Jilin University(Science Edition)"is a comprehensive academic journal in the fields of science sponsored by Jilin University and administrated by the Ministry of Education of the Peoples Republic of China.The journal started publication in 1955.The original name at starting publication was"Journal of Natural Science of Northeast People University",which was changed into"Acta Scientiarum Naturalium Universitatis Jilinensis"in 1958 owing to the name change of the university.The present journal name has