关于函数极值的几个定理

在函数极值的一般理论的基础上，得出了形如ｆ′（ｘ）＝ｇ（ｘ）φ（ｘ）的一类可导函数ｆ（ｘ）有极值的充分条件：设函数ｆ（ｘ）在ｘ０点的某邻域二阶可导，且ｆ′（ｘ）＝ｇ（ｘ）φ（ｘ），ｆ′（ｘ０）＝０．（１）若φ（ｘ０）＞０，则当ｇ′（ｘ０）＞０时，ｆ（ｘ０）为ｆ（ｘ）的极小值；当ｇ′（ｘ０）＜０时，ｆ（ｘ０）为ｆ（ｘ）的极大值．（２）若φ（ｘ０）＜０，则当ｇ′（ｘ０）＞０时，ｆ（ｘ０）为ｆ（ｘ）的极大值；当ｇ′（ｘ０）＜０时，ｆ（ｘ０）为ｆ（ｘ）的极小值．     

关于函数的不可导点

讨论了判定函数不可导点的两个基本方法。特别地，详细讨论了复合函数ｙ的不可导点的判定方法：在下列两种情况之一ｘ０必为的不可导点，１）ｆ（ｕ）在不可导，在ｘ０可导但在ｘ０不可导但连续，且，使在（ｘ０－δ，ｘ０）∪（ｘ０，ｘ０＋δ）。在ｕ０可导但ｆ＇（ｕ０）≠０．并应用上述方法给出了函数｜ｆ（ｘ）｜的有关结论：若ｘ０是ｆ（ｘ）的可导点，则ｘ０是｜ｆ（ｘ）｜不可导，久的充要条件是ｆ（Ｘ０）＝０且ｆ＇（ｘ０）≠０；若ｘ０是ｆ（ｘ）的不可导点，则ｘ０是｜ｆ（ｘ）｜的不可导点的充分条件是ｆ（ｘ０）＝０或ｆ（ｘ）在ｘ０点连续。     

半无界区域上算子L_q=~2/(t~2)-~2/(x~2) q(t)的反问题

讨论半无界区域上如下双曲方程确定函数偶（ｕ,ｑ）的反问题：ｕｔ－ｕｘｘ＋ｑ（ｔ）ｕ＝Ｆ（ｘ,ｔ）,ｘ＞０,ｔ＞０,ｕ（ｘ,０）＝φ（ｘ）,ｕｔ（ｘ,０）＝ψ（ｘ）,ｘ≥０,ｕ（０,ｔ）＝ｆ（ｔ）,ｔ≥０,ｕｘ（０,ｔ）＝ｇ（ｔ）,ｔ≥０．给出了局部解的存在性、唯一性和稳定性结果．     

一类四阶奇边值问题的可解性

运用Ｓｃｈａｕｄｅｒ不动点定理研究了四阶两点边值问题ｄ４ｙｄｘ４＝ ｈ（ｘ）Ｆ（ｘ,ｙ（ｘ））（０＜ ｘ＜ １）,ｙ（０）＝ ｙ（１）＝ ｙ″（０）＝ ｙ″（１）＝ ０ 的可解性,允许Ｆ（ｘ,ｙ）在ｘ＝ ０,ｘ＝ １ 或ｙ＝ ０,有奇性     

四阶非线性边值问题解的存在性和唯一性

本文利用Ｈａｍｍｅｒｓｔｅｉｎ型积分算子和上下解方法，研究了四阶非线性边值问题ｘ￣（４）＝ｆ（ｔ，ｘ，ｘ″），ｘ（０）＝Ａ，ｘ（１）＝Ｂ，ｇ（ｘ″（０），ｘ″（１））＝０，ｈ（ｘ″（０），ｘ″（１），ｘ″（０），ｘ″（１））＝０解的存在性和唯一性，改进了一些熟知的结果。     

具有强非线性源的非牛顿多方渗流方程的局部可解性

研究如下第一边值问题ｕｔ＝ｄｉｖ（｜Ｄｕｍ｜ｐ－２Ｄｕｍ）＋ｆ（ｘ,ｕ）（ｘ,ｔ）∈ＱＴ＝Ω×（０,Ｔ）ｕ（ｘ,ｔ）＝０（ｘ,ｔ）∈Ω×（０,Ｔ）ｕ（ｘ,０）＝ｕ０≥０ｘ∈Ω｛的可解性,得到了局部可解定理．     

反函数的导数定理的注记

给出反函数的导数定理的改进形式；若ｆ（ｘ），ｘ∈（ａ，ｂ）与ψ（ｙ），ｙ∈（Ａ，Ｂ）互为反函数，ｘ０∈（ａ，ｂ），ｙｐ＝（ｆ９ｘ０），ψ（ｙ）点ｙ０处可导且ψ（ｙ０）≠０，ｆ（ｘ）在点ｘ０处可导，且ｆ’（ｘ０）＝１／ψ（ｙ０），并说明，ｆ（ｘ）在点ｘ０处连续一条件不可去掉。     

混合型方程在矩形域上的非局部边值问题

给出了混合型二阶线性偏微分方程Ｌｕ≡ｈ（ｙ）ｕ＿（ｙｙ）＋ｕ＿（ｘｘ）＋ａ（ｘ，ｙ）ｕ＿ｙ＋ｂ（ｘ，ｙ）ｕ＿ｘ＋ｃ（ｘ，ｙ）＝ｆ（ｘ，ｙ）在非局部边界条件ｕ（ｘ，１）一ａｕ（ｘ，０）＝０，ｕ＿ｙ（ｘ，１）一ａｕ（ｘ，０）＝０，ｕ（１．ｙ）一βｕ（０，ｙ）＝０，ｕ＿ｘ（１，ｙ）－βｕ＿ｘ（０，ｙ）＝０下，在Ｓｏｂｏｌｅｖ空间中解存在及唯一的充分条件。     

一般二维非线性奇异抛物问题的有限元方法

考虑一般二维非线性奇异抛物问题ｕｔ － １ｐ （ｘ） ｘ （ｐ （ｘ ） ｕｘ ） － ２ ｕｙ２ ＝ ｆ（ｘ,ｙ,ｔ,ｕ（ｘ,ｙ,ｔ））,（ｘ,ｙ,ｔ） ∈ Ω× （０, Ｔ〕ｕ（ｘ,ｙ,ｔ）｜Γ ＝ ０, ｕｘ ｜Γ０ ＝ ０,（ｘ,ｙ,ｔ） ∈ Ω× （０, Ｔ〕ｕ（ｘ,ｙ,０） ＝ ｕ０ （ｘ,ｙ）,（ｘ,ｙ） ∈ Ω的对称有限元方法,给出了半离散格式和全离散格式的有限元解的加权 Ｌ２ 模和加权 Ｈ １ 模误差估计,并对全离散格式进行了线性化修正     

非线性奇异边值问题

利用上下解技巧讨论了奇异方程Ｘ＂＋ｆ（ｔ,ｘ）＝０满足非线性边值条件ｈ（ｘ（０）,ｘ＇（０））＝０,ｘ（１）＝０的正解的存在性,推广了一些已有的结果．     

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