关于群的计数的几个渐近公式

令Ｃ（ｘ），Ａ（ｘ），Ｎ（ｘ）分别表示阶ｎ≤ｘ且任一ｎ阶群都是循环群，Ａｂｅｌ群，幂零群的自然数ｎ的个数，本文证明了：Ｃ（ｘ）＝ｅ＾－ｒ／ｌｏｇ３ｘ＋Ｏ（ｘｌｏｇ４ｘ／ｌｏｇ＾２３ｘ），Ａ（ｘ）＝ｅ＾－ｒｘ／ｌｏｇ３ｘ＋Ｏ（ｘｌｏｇ４ｘ／ｌｏｇ＾２３ｘ），Ｎ（ｘ）＝ｅ＾－ｒ／ｌｏｇ３ｘ＋Ｏ（ｘｌｏｇ４ｘ／ｌｏｇ＾２３ｘ），Ｎ（ｘ）－Ａ（ｘ）＝ｅ＾－ｒｘ／ｌｏｇ＾２３ｘｌｏｇ＾２３ｘ＋Ｏ（ｘｌｏｇ＾     

次Hermite矩阵的次正定性

若ｎ阶次Ｈｅｒｍｉｔｅ矩阵Ａ，对任意非零向量Ｘ＇＝（ｘ＿１，ｘ＿２，…ｘ＿ｎ）∈Ｒ￣ｎ，有ＡＸ＞０，则称次Ｈｅｒｍｉｔｅ矩阵Ａ是次正定的．给出了判定次Ｈｅｒｍｉｔｅ矩阵次正定的几个充要条件：定理ｎ阶次Ｈｅｒｍｉｔｅ矩阵Ａ是次正定的，当且仅当下列条件之一成立：（ｌ）Ｈｅｒｍｉｔｅ矩阵ＪＡ是正定的；（２）存在ｎ阶可逆复矩阵Ｐ，使ＡＰ＝Ｊ；（３）次Ｈｅｒｍｉｔｅ矩阵Ａ的４ｋ阶，４ｋ十互阶下次主子式为正，４ｋ＋２阶，４ｋ＋３阶下次主子式为负；（４）存在ｎ阶可逆复矩阵Ｐ，使其中λ＿ｉ＞０，ｉ＝１，２，…，ｎ。     

实对称矩阵逆特征值问题的可解条件

该文考察以下２个逆特征值问题（１）问题（ＳＡ）；设Ａ＝（ａｉｊ）为ｎ阶实对称矩阵，其主对角元ａｉｊ＝０，ｉ＝２，．．．．ｎ，给定时角矩阵Ａ＝ｄｉａｇ（λ１，λ２，．．．．λｎ）∈Ｒ＾ｎ×ｎ，求一实时对角矩阵Ｘ＝ｄｉａｇ（ｘ１，ｘ２，．．．．ｘｎ）∈Ｒ＾ｎ×ｎ，使λ（Ａ＋Ｘ）＝λ（Ａ），（Ⅱ）问题（ＳＭ）：设Ａ（ａｉｊ）为ｎ阶实时对称矩阵，其主对角元ａｉｊ＝１，ｉ＝１，２，．．．．ｎ。给定对角矩阵Ａ     

给定阶群数的一个渐近公式

设ｘ是充分大的正实数，ｋ，ｎ表示正整数，以ｇ（ｎ）表示阶为ｎ的群的个数，Ｑｋ（ｘ）是满足ｎ≤ｘ及ｇ（ｎ）＝ｋ的无平方因数的正整数ｎ的个数。本文的目的是研究函数Ｑｋ（Ｘ）的渐过性质，给出一个渐过公式。     

一类非线性差分方程解的极限问题

研究了形如Ｅｘ（ｋ）＝Ａｘ（ｋ）＋ｆ（ｋ，Ｘ（ｋ））的非线性差分方程解的极限性质．Ｅｘ（ｋ）＝ｘ（ｋ＋１）．Ａ是ｎ×ｎ（ｎ≥２）阶常数矩阵．ｘ（ｋ）∈Ｒｎ．ｆ：Ｊ×Ｇ→Ｒｎ，Ｊ＝｛ｊ０＋ｋ｜ｋ＝１，２，…．ｊ０∈Ｒ｝，Ｇ．Ｒｎ．ｆ满足对任一紧集中的ｘ（ｋ）一致有ｆ（ｋ，ｘ（ｋ））→０，当ｋ→∞．利用差分不等式及比较原理得到：当Ａ的谱半径小于１时，方程的有界解均趋于零解．当Ａ的话半径大于１时，方程有无界解．并研究了所有解均趋于零解的充分条件．     

关于Beatty序列的加法

设［ｘ］表示ｘ的整数部分,Ａｘ（α）＝｛［αｎ］：ｎ∈Ｎ,αｎ≤ｘ｝,Ａｘ（β）＝｛［βｎ］：ｎ∈Ｎ,βｎ≤ｘ｝．作者给出了｜Ａｘ（α）＋Ａｙ（β）｜的估计式．     

交Hermite矩阵的次正定性

若ｎ阶次Ｈｅｒｍｉｔｅ矩阵Ａ，对任意非零向量Ｘ＾ｔ＝（ｘ１，ｘ２，…ｘｎ）∈Ｒ＾１，有Ｘ＾ＳＴＡＸ〉０，则称次Ｈｅｒｍｉｔｅｔ矩阵Ａ是次正定的。     

二面体群D2^n的自同构群及其全形

讨论了一类２＾ｎ阶群－二面体群Ｄ２＾ｎ＝〈ａ，ｂ│ａ＾２ｎ－１＝ｂ＾２＝１，ｂａｂ＾－１＝ａ＾－１）（ｎ≥３）的自同构群Ａ（Ｄ２＾ｎ）的置换表示，给出了Ａ（Ｄ２＾ｎ）与Ｈ（Ｄ２＾ｎ）的构造。     

分布尾等价与极值的矩收敛

设（Ｘｎ，ｎ≥）是公共分布为Ｆ（ｘ）的独立同分布序列（简称ｉｉｄ序列，下同），（Ｘ１，Ｘ２，…Ｘｎ）的第ｋ个（１≤ｋ≤ｎ）最大值为Ｍｎ＾ｋ，（Ｙｎ，ｎ≥）是公共分布为Ｇ（ｘ）的ｉｉｄ序列，（Ｙ１，Ｙ２…Ｙｎ）的第ｋ个（１≤ｋ≤ｎ）最大值为Ｍｎ＾ｋ，在Ｆ（ｘ）与Ｇ（ｘ）尾等价的条件下，讨论了Ｍｎ＾ｋ的ｌ（ｌ∈Ｎ）阶矩与Ｍｎ＾ｋ的ｌ（ｌ∈Ｎ）阶矩之间的收敛关系。得到定理 设Ｆ（ｘ）∈Ｄ（Ｈ），ｌ∈Ｎ（     

一类线性方程可化为常系数方程的条件

ｎ阶线性方程ｄ＾ｎｙ／ｄｘ＾ｎ＋Ｐｎ－２（ｘ）ｄ＾ｎ－２ｙ／ｄｘ＾ｎ－２＋…＋Ｐ１（ｘ）ｄｙ／ｄｘ＋ｐ０（ｘ）ｙ＝０在变换ｘ＝φ（τ）下可化为常系数线性方程当且仅当Ｐｉ（ｘ）＝Ｓｉ／（Ｃ１ｘ＋Ｃ２）＾ｎ－ｉ（ｉ＝０，１，…，ｎ－２）。     

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