考虑横向剪切效应的矩形板的弯曲

对于各向同性弹性厚板的 E.Reissner 基本方程的通解结构已在〔3〕中作过研究.本文全面地讨论了在板平面内各方向上和与之垂直方向上具有不同弹性性质的 E.Reissner 厚板基本方程的通解结构.根据这种通解结构和广义函数理论求出了非各向同性弹性的两对边简支的矩形板在集中载荷作用下的一般解和 Green 函数.最后,对本文理论和方法的应用范围作了一些讨论.     

半平面多圆孔多裂纹反平面问题

运用复变函数及积分方程方法,求解了半平面域多圆孔多裂纹反平面问题．建立了两种类型的基本解．利用叠加原理和所得的基本解并沿圆孔和裂纹表面取待定的基本解密度函数,可得一组基本解密度函数为未知函数的Ｆｒｅｄｈｏｌｍ积分方程．通过该积分方程组的数值求解可以得到密度函数的离散值,进而得到裂纹尖端的应力强度因子．     

无限域多椭圆孔多裂纹反平面问题

运用复变函数及积分方程方法 ,求解了无限域中的多椭圆孔多裂纹反平面问题 .建立了两种类型的基本解 .利用叠加原理和所得的基本解 ,并沿椭圆孔和裂纹表面取待定的基本解密度函数 ,可得一组以基本解密度函数为未知函数的 Fredholm积分方程 .通过该方程组的数值求解可以得到密度函数的离散值 ,进而得到裂纹尖端的应力强度因子 .     

弹性力学运动微分方程的解及其在简支矩形厚板振动中的应用

本文从弹性力学运动微分方程出发,引入了一个位移函数φ_r把运动方程的求解问题变成找位移函数φ满足一个六阶微分方程,用分离变量法求得了方程用直角座标表示的解,从而求得了位移和应力的表达式。根据简支矩形厚板受分布的或集中的周期力作用的条件定出了各常数,又根据板面外载荷为零的条件建立了简支矩形厚板的自振频率方程式。以正方形板为例对不同厚度的板求得了基本频率,并与由工程理论所得的薄板振动公式计算结果作了比较。     

几类函数方程的求解问题

函数方程的研究已有几百年的历史,至今仍有不少研究.这类问题在概率论、在各种欧氏与非欧氏几何学确定两向量的和时、在对初等函数重新定义和讨论方面都具有十分重要的意义.从前的研究都采用 Cauchy 方法:先在一稠密集上确定未知函数的值,然后连续延拓到整个实数直线上.最近,F.J.Papp 在(1)中研究达朗贝尔函数方程时提供了一种较简单易懂的方法,只用到微积分与常微分方程的一些基本概念和基本性质.本文讨论了五类更广泛的函数方程(方程中可以含有几个未知函数)的求解过程,而把通常的函数方程作为     

四边任意支承条件下弹性矩形厚板辛几何法解析解

利用辛几何法推导出了四边任意支承条件下矩形厚板弯曲的解析解.在分析过程中首先把弹性厚板弯曲问题的简化方程表示为H am ilton正则方程,然后利用辛几何法对全状态相变量进行分离变量,求出其本征值后,再按本征函数展开的方法求出四边任意支承条件下矩形厚板弯曲的解析解.由于在求解过程中不需要事先人为选取挠度函数,而是从厚板弯曲的基本方程出发,直接利用数学的方法求出可以完全满足其边界条件的解析解,使得这类问题的求解更加合理.计算实例验证了所采用的方法以及所推导出公式的正确性.     

弹性地基上固支矩形中厚板弯曲问题的辛方法研究

利用Hellinger-Reissner二类变量广义变分原理,推导了弹性地基上中厚板弯曲问题的哈密顿求解体系,采用辛几何方法对全状态相变量进行分离变量,按本征函数展开法得到问题的辛本征通解.由于在求解过程中不需要事先人为选取挠度函数,而是从地基上中厚板弯曲的基本方程出发,直接利用数学方法求解,使得这类问题的求解更加合理...     

关于一类混合型抛物—半抛物型方程的未知边界问题

这篇论文提出了在未知边界区域上的一类混合型抛物—半抛物型方程的初边值问题.利用本文的方法证明未知边界函数的唯一性,而利用抛物型方程极值原理,证明解的唯一性.     

厚板的随机响应

本文把厚板作为连续体,引用具有外阻尼和内阻尼的弹性厚板的振动方程对厚板的随机响应进行了分析,其中荷载用随机函数来描述,给出了厚板动力特性的解析表达式和厚板随机响应的一般表达式。文中以矩形板为例给出了数值结果。对按改进理论和经典理论所预示的结果进行了比较。     

Winkler地基上中厚板计算的重构核粒子法

重构核粒子法(reproducing kernel particle method,RKPM)是一种基于核函数近似的典型无网格方法.以RKPM法插值形函数为基础,基于Mindlin中厚板理论,建立Winkler地基上中厚板弯曲挠度的RKPM法求解控制方程,编制相应的计算程序,算例分析表明该方法有效可行.     

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     

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     

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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