正交异性体中半无限长界面裂纹扩展问题的自相似解

基于复变函数方法，给出了两种正交异性体结合面间半无限长裂纹的自相似解，本文方法可以把复杂边界条件转化为简单的Keldysh-Sedov混合边值问题，迅速地得到问题的闭合解，并给出实例，通过对其叠加，可以得到任意复杂半无限裂纹问题的解析解，最后给出应力强度因子的图表。     

强厚度叠层闭口悬臂圆柱壳轴对称问题的精确解

抛弃任何有关位移或应力模式的人为假设，在轴对称情况下导出正交异性体的状态方程。给出叠层闭口悬臂圆柱壳轴对称问题的精确解。此解满足所有基本方程，包含了全部弹性常数，可得到任意需要的精度。     

均布载荷作用下Ⅲ型非对称裂纹动态扩展问题

为了研究均布载荷作用下的Ⅲ型非对称裂纹动态扩展问题,利用复变函数论方法,根据正交异性体弹性动力学反平面问题运动方程的相应关系,采用自相似函数的方法可以获得解析解的一般表达式。应用该法可以迅速地将所讨论的问题转化为Riemann-Hilbert问题,后一问题可以用通常的Muskhel-ishvili方法求解,并求得了应力、位移和动态应力强度因子解析解。利用这些解并采用叠加原理,就可以求得任意复杂问题的解。这些解在断裂动力学以及弹性动力学、静力学问题当中具有重要的应用价值和理论意义。     

状态空间法分析正交异性板热弯曲问题

不考虑任何有关位移或应力模式的人为假设，从三维热弹性力学的平衡微分方程、几何方程和物理方程出发，导出正交异性体的热弹性力学问题的状态方程及其解.并就四边简支任意宽厚比矩形板加以说明其方法的应用，由于一次获得位移与应力场变量值，故精度较高.     

数值流形位移法在岩体裂缝扩展中的应用

基于三角形网格,对裂缝扩展过程中流形单元变化情况进行了深入研究,从几何网格的角度对数值流形方法的连续与非连续统一处理方式进行解读.采用一阶覆盖函数,推导出数值流形算法的权函数表达式,建立局部位移函数.通过数值流形计算程序,得出裂缝尖端位移,并计算尖端应力强度因子.通过经典的中心裂纹板模型,对数值流形位移法求得的尖端应力强度因子进行验证,算例的数值解和解析解吻合度较高,证明数值流形法计算裂缝扩展的准确性,为裂纹扩展过程中尖端应力强度因子的求解提供了新的数值解法.     

垂直位于一类双材料界面的裂纹对称变形尖端场

基于平面问题中各向同性与正交各向异性材料奇异点附近渐近场的基本解,文章给出了对称变形条件下端部位于正交异性/各向同性双材料界面的垂直裂纹裂尖应力奇异性的特征方程以及相应的位移场与奇异应力场的解析解。为了验证解析解的正确性,通过1个算例将应力奇异性指数和奇异应力分量角函数的理论值与有限元分析结果进行了对比,两者吻合得相当好。     

云纹干涉法测定复合材料拉伸试件的应力强度因子

本文采用贴片云纹干涉实验方法,测试并研究了带单边裂纹正交异性材料拉伸试件的应力强度因子。从理论上推导出位移与应力强度因子之间的关系式,给出拉伸试件云纹图,实测应力强度因子KⅠ及kⅡ.     

求解含裂纹正交各向异性平面问题应力强度因子的耦合法——位移间断法与边界元法的耦合

本文在推导出正交各向异性平面位移间断基本解的基础上,建立了一组求解裂纹表面位移的方程,并较精确地求出应力强度因子K_I和K_Ⅱ。将这一方法与边界元法相耦合,解决了含孔洞及裂纹群复杂问题。随着边界单元数目的增大,数值结果迅速趋于某一极限(精确解)。通过与现有数值结果比较,本耦合法具有很高的精度和极强的收敛性。     

任意点载荷下含椭圆孔压电介质中广义应力和位移分析

以孔边加载下的Stroh广义应力、广义位移表达式为基础，考虑椭圆孔边界精确的电学边界条件，显式给出在任意点处作用广义点载荷时介质中广义应力函数的表达式．当椭圆孔退化成中心裂纹时，给出了导通裂纹端部的广义应力函数．所得结果为介于绝缘边界条件和导通边界条件下更一般的解．进一步推导了压电介质中一本征变形夹杂对椭圆孔边缘广义应力的影响，所得结果对研究铁电畴变区具有实际意义．     

各向异性与正交异性双材料Ⅲ型界面裂纹分析

研究了各向异性与正交异性双材料Ⅲ型界面裂纹问题.通过构造新的应力函数,采用复合材料断裂复变方法,求解一类偏微分方程组边值问题,推导出各向异性与正交异性双材料Ⅲ型界面裂纹尖端附近的应力场、位移场以及应力强度因子的表达式。结果显示裂纹尖端附近应力具有r-1/2的奇异性,但没有振荡性;通过算例得到应力随极径r变化的规律;分析当角α=0时,获得了正交异性双材料Ⅲ型界面裂纹的应力场、位移场与文献一致,验证了结果的正确性。     

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。     

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.     

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