首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 62 毫秒
1.
n阶矩阵A称为完全正的,如果A有分解:A=BBt,其中B为(不必方)元素非负矩阵.B的最小可能列数称为A的分解指数.本文给出了一个5×5阶双非负矩阵A为完全正的充分条件.  相似文献   

2.
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.  相似文献   

3.
N阶矩阵A称为完全正的,如果A能分解成A=b1bt1+…+bmbtm,其中bj(j=1,2,…,m)为n维非负向量。满足此式的最小的正整数m称为A的分解指数。本文证明了一个秩≤2的非负半正定矩阵一定为完全正,并给出了一个秩为3的非负半正定矩阵为完全正的一个充分条件。  相似文献   

4.
设A是一个非负矩阵,若存在正整数k,使得A~k>0,则称A为本原矩阵,而上述k的最小者称为A的本原指数,记作γ(A).设m为A的最小多项式的次数,g为A的伴随有向图的围长,当g≤m-1时,猜想γ(A)≤(m-1)~2+1成立。  相似文献   

5.
设p是一个给定的素数,α,β为p-adic单位,cn为同余式αxα≡βy~b(modpn)对的解数.本文给出了cn直接公式的一个简化形式,并由此证明了cn≡0(modpn-1).  相似文献   

6.
Lukasiewicz系统中的广义重言式理论   总被引:18,自引:1,他引:17  
引入了一类特殊的公式序列AK(K=1,2,...)从而证明了在Lukasiewicz系统中广义重言式有更加精细的区分,即在连续值或有理值的情形下对任意真值α和β,并给出了广义重言式的关系定理,即对任意真值α,α-T(L)=β〈α,β∈(L)β-T(L)。  相似文献   

7.
Lukasiewicz系统中的广义重言式理论   总被引:8,自引:3,他引:5  
引入了一类特殊的公式序列Ak(k=1,2,…),从而证明了在Lukasiewicz系统中广义重言式有更加精细的区分,即在连续值或有理值的情形下对任意真值α和β,若α≠β,则有α-T(L)≠β-T(L).并给出了广义重言式的关系定理,即对任意真值α,α-T(L)=∩β<α,β∈(L)β-T(L).  相似文献   

8.
本文目的是研究两卵形弧间的等距对应,所得的主要结果是下列两定理:定理设C和C ̄*是两条正则的卵形线,它们的长度相等,C→C ̄*是等距映射,则在C上有4个不同的点A1、A2、A3、A4使C在A_i的曲率等于C*在=1,2,3,4.)。定理设C和C ̄*都是以A、B为端点的卵形弧,它们的长度相等;C→C ̄*是等距映射使;M为C上一点;对于AM上任P有对MB上任一点心P有.则α*≤α,β≥β*其中α(α*)是C(C ̄*)在A的弦切角,β(β ̄*)是C(C ̄*)在B的弦切角。  相似文献   

9.
给出了序集W为半整序集的充要条件是W的非空真前段有形A(x0)及A[x0]。在半整序集上建立了超穷归纳法原理:设W是一个半整序集,P是一个性质,如果下列命题成立,则W的所有元素均具有性质P.(1)若α<x<β具有性质P,则α,β具有性质P;(2)一串不具有性质P的点的极限点亦不具有性质P.  相似文献   

10.
给出了方差分量模型Y=Xβ+∑^mi=1Uiεi,U1U1’=…=UmUm’〉0中方差分量(o^21,…,o^2m)的非负二次同时估计(Y’A1Y,…,Y’AmY)可容许的一个必要条件。  相似文献   

11.
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.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
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.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
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.  相似文献   

14.
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.  相似文献   

15.
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。  相似文献   

16.
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.  相似文献   

17.
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.  相似文献   

18.
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-  相似文献   

19.
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-  相似文献   

20.
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  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号