有中心集中荷载作用的任意变厚度的旋转扁薄壳的非线性弯曲

中心集中荷载作用的变厚度圆板或旋转扁壳的轴对称非线性弯曲,迄今鲜见研究成果.取三次B样条函数和对数函数为试函数,用配点法计算任意变厚度圆板的大挠度和旋转扁壳的非线性稳定.计算了中心集中荷载作用的圆板及它和反向均布荷载同时作用圆板且其中心挠度为零的特殊情形.给出了中心集中荷载作用下,线性或多项式型变厚度的圆锥壳、球壳或四次多项式型旋转壳的上、下临界荷载.等厚度圆板和球壳的计算结果同其他方法的结果做了比较.结果表明样条配点法有更高的精度和更大的荷载收敛范围.     

正交异性悬臂矩形板弯曲的Rayleigh—Ritz解

构造多项式和三解函数的混合形式作为挠度试函数,用Ｒａｙｌｅｉｇｈ－Ｒｉｔｚ法求解了正交异性悬臂矩形板的弯曲问题。文中精度可以满足工程要求,求解过程也较为简单。     

径向裂纹圆板的振动与辐射声场

在将裂纹板挠度表示为正交多项式之和的基础上,利用瑞利 里兹方法,求解了周界固定径向裂纹板的低阶振动模态频率及挠度;进而利用瑞利积分,求解了裂纹圆板自由振动辐射声场的轴向声压分布及距板心50cm球面上声场的指向性,并与完整板的辐射声场作了对比.用撞击法测定了裂纹圆板辐射声场的频谱,结果与理论值及有限元法求得的结果基本符合.     

关于一种固支边异形圆板挠度试函数的研究

从解的收敛性，位移边界条件及内力边界务件等方面论证了一种固支边界异形圆板挠度试函数的形式，为利用Ｇａｌｅｒｋｉｎ法或Ｒｉｔｚ法求解这种板的弯曲问题提供了如何选择挠度试函数的途径。     

径向裂纹对周界固定薄圆板振动频率的影响

将裂纹板挠度表示为正交多项式,用分区技术的瑞利-里兹方法求解了含不同长度径向裂纹的周界固定圆板振动频率,探究了不同长度径向裂纹对圆板频谱的影响规律。实验采用小球撞击法测定了径向裂纹圆板的辐射声场频谱。结果表明,理论计算值与有限元法结果、实验结果符合较好。     

中心受集中载荷作用下的波纹圆板大挠度问题的精确解

本文运用均匀致密的波纹圆板的极正交各向异性板的几何非线性理论，对于中心受集中载荷作用的波纹圆板，应用级数解法给出了其大挠度问题的精确解表达式，并以固定夹紧边界的情形作为算例，进行了详细的数值计算。     

中受集中载作用下的波纺圆板大挠度问题的精确解

本文运用均匀致密的波纹圆板的极正交各向异性板的几何非线性理论，对于中心受集中载荷作用的波纹圆板，应用级数解法给出了其大挠度问题的精确解表达式，并以固定夹紧边界的情形作为算例，进行了详细的数值计算。     

复合载荷作用下波纹圆板和环形板的大挠度问题

本文以正交各向异性圆板的非线性弯曲理论为基础,用Chebyshev级数研究了在均布压力和中心集中载荷共同作用下,波纹圆板及具有硬中心的波纹环形板的大挠度问题。处理和分析了波纹板中心挠度为零的特殊情况并进行了具体求解,这是一种新的尝试和探索。用圆薄板的计算结果验证了本文方法的可靠性。文中还给出了波纹圆板和带硬中心的波纹环形板的数值结果。     

中心受载下具有平面边缘区域的固支波纹环形板的非线性分析

应用圆柱正交各向异性圆板的非线性弯曲理论研究了具有平面边缘区域和刚性中心的波纹环形板在中心集中载荷作用下的大挠度问题．使用修正迭代法，得到了具有夹紧固定和滑动固定两种外边界条件的波纹环形板的解析解，最后，用数例讨论了平面边缘区域和刚性中心的大小对弯曲的影响．     

用贝塞尔函数作试函数及权函数解圆板的弯曲和稳定

本文用加权残数法,以贝塞尔函数作试函数和权函数,解决了圆板的轴对称弯曲,非轴对称弯曲,弹性地基上圆板的弯曲及圆板的稳定,圆板的大挠度弯曲。在五个例题的计算中都取得满意的结果。     

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.     

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