伯特兰猜测的推广与证明

(n,2n)中至少有一个素数,称为伯特兰猜测(华罗庚,1979),其正确性首先为俄国数学家切必雪夫所证明。但一百多年来,此猜测未能再进一步。本文将这一猜测推广为:a>1,n充分大时,(n,an)中至少有一个素数。并由此推出:对任何正整数k,n充分大时,(n,2n)中至少含有k个素数。     

梅森素数的分布规律

本文从已知的梅森素数出发,探讨梅森素数在自然数中的分布规律;提出了在2~(2~n)与2~(2~(n 1))之间梅森素数的个数为2~(n 1)-1的猜想,并据此做出了小于2~(2~(n 1))的梅森素数的个数为2~(n 2)-n-2的推论。     

一个素数猜想的反例

对于正整数n,设pn是第n个素数。本文证明了:不等式穴n 1雪pn-npn 1<12穴n 1雪950对于某些正整数n不成立。     

关于素数的一个猜想

对于正整数n，设pn是第n个素数。本文证明了：不等式（√pn-logpn＋1）/（√pn＋1＋logpn）≥（√3-log5）/（√5-log3）对于任何正整数n都成立。     

探讨P.Erdos对Bertrand假设的初等证明及对其结果的改进

在原有Bertrand假设的基础上，利用并改进P.Erdos的证明方法，得到了n充分大时比(n，2n)较小的区间(n，n k)(其中n／2＜k＜n)上必有素数的结论，其中常数k的近似取值为[8n／11]．     

关于同余式2n≡5(mod n)的解

证明了同余式2n≡5(mod n)(n＞1)在［2，4294967295］中除平凡解n=3外，仅有解n=19147=41·467,以及若m＞1满足2m≡5(modm)，则n=2m-1是2n-4≡1（modn）的解.     

关于素数的一个不等式

对于正整数n,设pn是第n个素数. 本文证明了:exp((n 1)/pn 1)/exp(Pn/n)〈exp(3/5)exp(3/2)     

关于纯形素数无限性

纯形素数的发现是在1986年。以下提供的数据是近年用计算机验算检索的首批数据(p<10~6)。纯形素数在分布规律的特点大大优于Fermat素数。Mersrne素数,由于数据显示出对任意正整数n而言,在n~3与(n十1)~3之间至少存在3个统形素数,如果证明了统形素数无限多,则抓住了素数集合的核,到那时我们应该正式命名纯形素数为核素数。本文的初步分析表明,要想证明纯形素数无限多,则需对数论的基础理论作出重大发展。     

亲和数的一种求法

讨论了亲和数的一种求法,并得出了求亲和数的一个公式,即当m=atpq,n=at(pq+p+g)时,m和n为一对亲和数.     

探讨P.Erd(?)s对Bertrand假设的初等证明及对其结果的改进

在原有Bertrand假设的基础上,利用并改进P.Erdos的证明方法,得到了n充分大时比(n,2n]较小的区间(n,n+k](其中n/2相似文献   

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