短码长二元循环码的局部修复度

局部修复码是一种局部纠删编码,近年来在分布式存储系统中得到了广泛的应用。码的局部修复度为r指的是,码字的任一位发生删除错误时至多需要该码字的其他r位进行恢复。研究了r≤3的二元循环局部修复码的存在性与构造。基于循环码定义集理论,采用局部修复码的对偶码描述,依据码的参数制约关系,进行局部修复码的构造及参数优化。证明了r=1的任意码长二元循环码的存在性,构造了r=1且参数达到Griesmer界的局部修复码;给出了r=2和r=3的部分码长二元循环码存在性的判据,基于7≤n≤99的二元循环码分别构造了r=2和r=3的、参数优良的短码长局部修复码。研究结果对进一步研究循环码的局部修复度与其他参数的关系、构造参数优良的一般码长局部修复码具有借鉴作用。     

一类向量不规则小波标架

研究了一类向量小波系统{tl,j1/2Ψl(tlj·-kbl):1≤l≤r,j,k∈Z}.对{Ψl}1≤l≤r, {tl,j}1≤l≤r,j∈Z及{bl}1≤l≤r施加一定的条件,这类小波系统生成L2(R)的标架.     

用有限局部环Z/2kZ上m阶斜对称矩阵构作的卡氏验证码

设R=Z/ 2kZ(k＞1),Wm(R)(m=2v 2≥4)是R上所有m阶斜对称矩阵构成的集合,WmA(R,Hr1r2)={A∈Wm(R)|PAP'=Hr1r2}是Wm(R)中一切与Hr1r2合同的斜对称矩阵构成的集合,令F=∪0≤r1＜r2≤k-1WmA(R,Hr1r2),其中Hr1r2=Dr1(◎)Δr2,Dr1=02-r1I(v)-2-r1I(v)0,Δr2=2-k-12-r2-2-r20-,v≥1,0≤r1＜r2≤k-1.利用F中矩阵构作一个Cartesian验证码,计算其全部参数.     

k,r≤10的尚未解决存在性问题的PBIB(2)设计参数组

1964年我们已经系统地列举了k,r≤10(λ_1≠λ_2 )的PBIB(2)D(具有两个结合类的部分平衡不完全区组设计)的全体参数组,即可分组GD(m,n)方案,v=mn(m,n≥2),Kr≥vλ_2,max(0,2r-b)≤λ_i;≤r,max(1,2r-b)≤λ_2≤r;均衡参数U(n),v=4n+1(n≥1),max(0,2r-b)≤λ_1<λ_2 <1;三角参数 T(n),v=n(n-1)/2(n≥5);正交拉丁参数K_m(n),v=n~2,2≤m≤n/2;零星类M(v,1_1,P_(11)~1),max(0,2r-b)≤λ_i≤r.共有1987组这种参数.包括大量作者的结果,在这些参数组中,有785组没有关于设计的解;829组有解(W.H.Clatworthy于1973年发表的表[5]收集并列出了其中759组的解);剩下373组有无解的问题尚未解决.对于设计以及对于有关结合方案的分类数目列表如下:对于解的存在性问题尚未解决的373组设计参数、以及114组有关的方案参数,本文按照类别分别列出了参数组,提供了大量的未解决问题.     

半群T_(n,r)的极大(正则)子半群的完全分类

设S_n和T_n分别是X_n={1, 2,…,n}上的对称群和全变换半群.对1≤r≤n,令T(n,r)={α∈T_n:|im(α)|≤r},则T(n,r)是全变换半群T_n的双边理想.对1≤r≤n-1,考虑半群T_(n,r)=T(n,r)∪S_n,得到了半群T_(n,r)的极大子半群S有且仅有两类:S=T_(n,r)\[τ_i](1≤i≤p=p_r(n))和S=T(n,r)∪G,其中G是群S_n的极大子半群.同时,证明了半群T_(n,r)的极大子半群和极大正则子半群是一致的.所得结果推广了已有的结果.     

基于Ⅱ型截尾样本下Rayleigh分布参数的条件置信限

Rayleigh分布是很重要的寿命分布 ,单参数Rayleigh分布的参数推断问题在一些文献中已有讨论 .本文假设寿命X服从双参数Rayleigh分布 ,即X有密度　　f(x ;μ ,σ) =2 (x - μ)σ e(x- μ) 2σ 　　x>μ ;-∞ <μ <∞ ;σ >0通过Ⅱ型截尾样本的前r个次序统计量 :X(1 ) ≤X(2 ) ≤…≤X(r) (r≤n) ,首先推出了枢轴量Z1=( ^μ - μ) 　^σ,Z2 =^σ σ建立在可观测的辅助统计量a =(a1 ,a2 ,… ,ar) (ai=(X(i) - ^μ)　^σ;μ ,^σ分别为参数 μ ,σ的极大似然估计 )基础上的条件分布 ,据此得到了参数 μ ,σ的条件置信限 (置信区间 ) ,最后 ,给出了p分位点xp 的置信区间和Rayleigh分布的容许限的计算方法 .     

半群MC(n,r)的极大子半群

设Xn={1,2,…,n}并赋予自然数序,MCn是Xn上的单调压缩奇异变换半群.对任意3≤r≤n-1,考虑半群MC(n,r)={α∈MCn:Imα≤r},得到了半群MC(n,r)的极大子半群的完全分类.     

半群SPOn中理想的非群元秩和相关秩

设自然数n≥3,SPOn是有限链[n]上的严格部分保序奇异变换半群.对任意的r(0≤r≤n-2),记N(n,r)={α∈SPOn:|Imα|≤r}为半群SPOn的双边理想.通过对其非群元和格林关系的分析,分别获得了半群N(n,r)的极小非群元生成集、非群元秩和非幂等元秩.进一步确定了当0≤l≤r时,半群N(n,r)关于其理想N(n,l)的相关秩.     

二阶双曲型方程双参数差分格式

对一维二阶双曲型方程2u/t2=C2 2u/x2,构造了一个双参数三层差分格式,并讨论了它的稳定性与收敛性.当参数适当选取时,其局部截断误差阶可达O(τ4+h4)或O(τ6+h6),且其稳定性条件为r=Cτ/h≤1或r=1.     

矩阵1秩半群的自同构

设D~(n×n)是体D上的n×n矩阵半群,整数r适合0≤r≤n,称s_r={X∈D~(n×n)|ranKX≤r}为D上n阶矩阵r秩半群。在r≤1的限制下,确定了S_r的自同构形式。     

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.     

橡胶颗粒沥青混合料低温抗裂性试验研究

以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.     

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-