一类Lucas数与三角函数乘积的封闭形和式

用发生函数的方法得到和式∑nk=0Ur tkdk及∑nk=0Vr tkdk的封闭形计算公式,利用复数De.Moivre公式给出Lucas数与三角函数乘积的和式∑nk=0Ur tkcoskα及∑nk=0Vr tkcoskα的封闭形计算公式.     

推广Weierstrass无处可微连续函数∑a^kcosb^kπx的一种方法

本文给出了形如∑ａｋｃｏｓｂｋｘ，∑ａｋｓｉｎｂｋｘ，∑ａｋｃｏｓｂｋπｘ∑ａｋｓｉｎｂｋπｘ的函数连续且无处左、右方可导的一个充分条件，并给出了∑ｃｋａｋｃｏｓｂｋｘ及∑ｃｋａｋ／ｋｃｏｓｋｘ等类更具体的函数连续且无处左、右方可导的充分必要条件。     

非理想∑△调制器的概率性质

本文提出了一种推导∑△调制器输出等于逻辑１的概率方法，并研究了非理想因素对概率特性及∑△比特流信号处理的影响。     

关于概率多项式时间谱系的一些结果

研究概率多项式时间谱系的结构性质,证明了:(1)如果BP∑_(k+1)~pBP∑_k~P,则PH=BP∑∏_K~P;(2)如果BP∑_k~PBP∏_k~P,则;PH=BP∑_K~PP;(3)对任意n,k≥0,BP∑_K~P(BP∑_n~P)=BP∑_(n+k)~p,BP∑_n~P(BP△_(k+1)~P)=BP∑_(n+k)~n;(4)对任意n,k≥1,BP∑_n~P(BP∑_k~p∩BP∏_k~P)=BP∑_(n+k-1)~P这些结果说明概率多项式时间谱系与多项式时间谱系有相同的结构性盾,但也有差别.     

一类变时滞的中立型微分方程的稳定性

利用Lyapunov函数及不等式,研究了一类变时滞线性中立型微分方程[xi(t)-n∑j=1aijxj(t-τj)]’=bixi(t)+n∑j=1cijxj(t-δj(t))+n∑j=1dijxj(t-ξj)的稳定性,并得到该方程的零解渐近稳定的充分条件.     

过采样∑-△ADC的原理及单片机实现方法

论述了过采样∑-△ADC的基本原理及结构，分析了∑-△调制器的频域传输特性和系统的信噪比，给出了实现不同的A／D转换精度必须满足的条件和用单片机实现∑-△ADC的具体方法和电路。实际使用表明，该方法测量结果可靠，具有实用价值。     

分子能级及辐射常数的计算

分子辐射常数可用振子强度来表征。提出了计算分子的电子态能级其及跃迁的振子强度的方法。计算了氮分子X~1∑_g~ ,A~3∑_n~ ,B~3∏_g,C~3∏_u和D~3∑_u~ 态的能级以及第一、第二和第四正带系的振子强度,计算值与实验值完全吻合。     

关于∑cos~3A／2及其几何不等式

证明和推翻了关于三角形几何不等式∑ｃｏｓ￣３的若干猜想，解决了在等腰三角形、直角三角形及一般三角形等有关条件下∑ｃｏｓ￣３的上、下限问题，建立了关于∑ｃｏｓ￣３的一系列新几何不等式。     

Σ3和Σ5晶界对Ni3Al力学性能影响的原子模拟

应用分子动力学的方法研究了纳米合金Ni₃Al加入∑3和∑5晶界后在单轴加载下的力学性能。研究结果表明：Ni₃Al合金中加入∑3和∑5晶界后使Ni₃Al合金的应力-应变曲线发生了改变，导致合金的屈服应力和屈服应变降低，但是弹性模量的数据显示∑3晶界对Ni₃Al合金的机械强度具有强化作用，∑5晶界对Ni₃Al合金机械强度产生弱化现象。通过对微观机理分析得到Ni₃Al-∑3和Ni₃Al-∑5的主要的塑性变形都是滑移带，∑3和∑5中的产生滑移带比Ni₃Al优先形成，其中∑3中的产生的大量交叉滑移带比∑5中的长滑移带更能有效地抵制外载引起的结构损伤，起到了强化作用。     

∑-协议的几个性质

∑-协议是密码学领域中的一种重要工具.论文证明了关系R上的∑-协议具有如下的几个性质:①如果关系R至少存在两个证据,则在关系R上的∑-协议是证据隐藏协议;②在单项置换存在的假设下,任意NP问题具有∑-协议;③存在计算零知识的∑-协议;④∑-协议可转换为零知识证明.     

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     

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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Brief Introduction to “Journal of Jilin University( Science Edition) ”

<正>"Journal of Jilin University(Science Edition)"is a comprehensive academic journal in the fields of science sponsored by Jilin University and administrated by the Ministry of Education of the Peoples Republic of China.The journal started publication in 1955.The original name at starting publication was"Journal of Natural Science of Northeast People University",which was changed into"Acta Scientiarum Naturalium Universitatis Jilinensis"in 1958 owing to the name change of the university.The present journal name has