实二次域上的一个Diophantine方程

设a,b,D,k是适合gad(a,b)=gcd(D,k)=1,a2-Db2=k的正整数;又设α=a+b D,β=a-bD.本文证明了当D是非平方数且k含有适合p≡±3(mod8)的素因数p时,方程α2n+β2n=2x2没有正整数解(x,n).     

有关方程φ(ab)=k(φ(a)+φ(b))的正整数解

设φ(m)为Euler函数.本文探讨了方程φ(ab)=8(φ(a)+φ(b))的正整数解,利用初等方法给出了该方程的所有正整数解.根据方程φ(ab)=8(φ(a)+φ(b))正整数解的结论和已被讨论的相类似方程的正整数解的结论,证明了以下2个结论:对于任意正整数k,(a,b)=(2k,2k)是方程φ(ab)=k(φ(a)+φ(b))的1个整数解;对任意的正整数k,(a,b)=(~(2k+1),2~k×3)和(2~k×3,2~(k+1))是方程φ(ab)=2~k(φ(a)+φ(b))的2个正整数解.     

关于Diophantine方程x~(d(n))+y~(φ(n))=z~(σ(n))

对于正整数n=2tpa11pa22…pakk,这里pi是奇素数,mi是正整数,i=1,2,…,k,2p1p2…pk,t是非负整数.设d(n),φ(n),σ(n)分别表示n的约数函数,Eu ler函数和约数和函数.给出了:n=2和3时,方程xd(n)+yφ(n)=zσ(n)正整数解的一般公式;并证明了ai(i=1,2,…,k)中至少有两个为奇数或存在i及奇素数p,使pi≡1(modp)且ai≡-1(modp)两种情形时,方程xd(n)+yφ(n)=zσ(n)没有正整数解.     

关于奇素数方幂中的孤立数

设n是正整数,用σ(n)表示n的所有正因数的和。对于给定的正整数a,如果不存在正整数b适合σ(a)=σ(b)=a+b,则称a是孤立数。文章运用初等数论的方法证明了pr都是孤立数。这里p为奇素数,满足p>2r~(1+ε),0<ε≤1,ε是任意实数,r是正整数,满足r>((1+ε)/ε)~1/ε     

关于广义Fermat数F_(6,1,n)的一个结论

对于任意的正整数n,σ(n)表示n的所有不同因子的和.若存在不同的正整数a,b,c满足σ(a)=σ(b)=σ(c),则称a,b,c为亲和三数组.在此给出了广义Fermat数F(6,1,n)=62n+1不与任何正整数构成亲和三数组的结论.     

数论函数方程tφ(n)+φ2(n)=S(SL(nk))的正整数解

设t∈N,n∈Z⁺,其中N和Z⁺分别是所有非负整数集合和所有正整数集合，利用欧拉函数φ(n)、广义欧拉函数φ₂(n)、Smarandache LCM函数SL(n)和Smarandache函数S(n)的性质以及初等数论的方法，得到了方程tφ(n)+φ₂(n)=S(SL(n¹³))只在t=0、1、2、3、4、5、7、10、13、15时有正整数解n及方程tφ(n)+φ₂(n)=S(SL(n¹⁸))只在t=0、1、3、6、7、9、14、18、19时有正整数解n,并给出了这两个方程的所有正整数解n。     

定积分的换元法

在不定积分中,其中之一的积分方法:设y=f(x),x=φ(t)及f′(t)都是连续的,x=φ(t)的反函数t=φ~(-a)(x)存在且可导,并且∫f[φ(t)]·φ′(t)dt=F(t)+C,则∫f(x)dx=F[φ~(-a)(x)]+C。在定积分中的换元法则是:对于定积分integral from n=a to b(f(x)dx),其中f(x)在区间[a,b]上连续,如果函数x=0φ(t)满足下列条件(1)φ(t)在区间[α,β]上有定义′是单值的′单调的,且有连续导数φ′(t)。(2)当t在区间[α,β]上变化时,x=φ(t)的值在区间[a,b]上变化,在这些条件下,则有公式integral from n=a to b(f(x)dx)=integral from n=α to β(f[φ(t)·φ′(t)dt)     

关于Nicol数的两个问题

对于正整数n,设φ(n)和σ(n)分别是n的Euler数和约数之和,当n︱φ(n)+σ(n)时,n称为Nicol数.运用初等方法讨论了Nicol数的存在性,设a=p1α1p2α2…prαr,其中r是大于1的正整数,pi(i=1,2,…,r)是不同的奇素数,αi(i=1,2,…,r)是正奇数,证明了如果n=a或2a,则n不是Nicol数.     

三阶段时滞种群生长模型的渐近稳定性

根据种群生长的阶段性,引入时滞建立了一类三阶段结构的时滞种群生长模型:{_1(t)=αx_3(t)-γx_1(t)-αe~(-γτ)x_3(t-τ)_2(t)=αe~(-γτ)x_3(t-τ)-bx_2(t)-αx_2(t),_3(t)=ax_2(t)-cx_3(t)-dx_3~2(t),初始条件:{x_1(t)=φ1(t)≥0,x2(t)=φ_2(t)≥0x_3(t)=φ_3(t)≥0,t∈[-τ,0]。利用微分方程稳定性理论分析了系统的零平衡点和正平衡点的局部稳定性。利用有效的Liapunov函数得到零平衡点和正平衡点的全局稳定性:1)当aαe~(-γτ)(b+a)c时,系统有唯一平衡点E_0,且它是局部稳定的;当aαe~(-γτ)(b+a)c时,E_0是不稳定的,此时系统除了E_0外,还存在唯一正平衡点E_*,且它是局部稳定的。2)当αe(-γτ)≤c,则系统的平衡点E_0是全局渐进稳定的,当αe~(-γτ)≥(a+b/a-b)c,ab,则系统的正平衡点E_*是全局渐进稳定的。所得结论对人工控制种群的发展具有一定的指导意义。     

三元欧拉函数方程φ(abc)=φ(a)+3(b)+5φ(c)的正整数解

研究了欧拉函数方程φ(abc)=φ(a)+3(b)+5φ(c)的正整数解,φ(n)是欧拉函数。通过初等数论中的相关知识、方法与技巧,得到了该方程的19组正整数解。     

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.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

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.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

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-