一类非自治超二次二阶Hamilton系统的周期解

使用局部环绕定理和推广的山路引理，得到了二阶Hanmton系统在满足新的超二次条件下周期解存在的结果．     

二阶超线性哈密顿系统周期解的存在性

研究二阶哈密顿系统-ü(t)+[-K(t,u(t))+W(t,u(t))]=0周期解的存在性及多重性,通过使用山路定理,得到了当W为超线性时,系统无穷多个周期序列解的存在性。     

一类局部超二次二阶Hamilton系统周期解的存在性

利用山路引理证明了一类具有局部超二次势能的二阶Hamilton系统周期解的存在性,这里的"局部超二次"是指,超二次条件在更小的区间[a_1,a_2]■[0,T]而不是[0,T]上成立,推广了先前文献的结果,并给出了例子.     

二阶哈密顿系统的同宿轨道(英文)

对于一个二阶哈密顿系统-L(t)u(t)-▽W(t,u(t))=0,t∈R,通过用局部环绕引理,得到至少两个非平凡的同宿轨道,其中W(t,u)是超二次的.     

非自治超二次齐次二阶Hamilton系统的次调和解

用约束极小化方法得到了一类非自治超二次齐次二阶Hamiltonian系统无穷多个不同的次调和解的存在性．     

一类次二次二阶Hamilton系统的周期解

利用临界点理论中的鞍点定理和变分法方法,在新的次二次条件下得到了一类二阶Hamilton系统周期解的存在性.     

一类共振二阶系统的多重周期解

利用Z₂型山路定理,获得关于形如ü(t)+k²ω²u+▽F(t,u(t))=0(a．e．t∈[0,T])的超二次共振非自治二阶系统,当无界时,多重周期解存在性的定理．     

又一类二阶二次微分方程的解法

给出一类二阶二次微分方程ａ１（ｘ）ｙｙ″＋ａ２（ｘ）ｙ′２＋ａ３（ｘ）ｙｙ′＋ａ４（ｘ）ｙ＾２＝ｂ（ｘ）的解法。     

二阶电路系统设计中的一类逆二次特征值问题

应用广义逆矩阵理论和线性代数理论研究了二阶电路系统的逆二次特征值问题,即构造二阶电路系统(M、C、K)使之具有预先给定的六个特征值和两个特征值,给出了解的存在性和解的表达式,数值算例说明了算法的有效性.     

受到干扰的仿射非线性系统超二次最优控制问题

研究了带初始和持续干扰的仿射非线性系统超二次最优控制问题，引进了相应控制问题的Ｒｉｃｃａｔｉ方程并刻划了原最优控制问题与相应Ｒｉｃｃａｔｉ方程之间的密切关系。     

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.     

Jane Eyre——A Feminist In The 19th Century

In the 19th century the society was controlled by men, and women were just appendants of them, they had not any rights and freedom. But Jane was an exception, she showed some characteristics of early feminist. Jane showed her characteristics of feminism in three aspects: rebellion, equality, and independence. These characteristics were helpful to her success, and feminism is the only way out for women of that time.     

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