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 729 毫秒
1.
设自然数n≥3,OInk是有限链[n]上的双边k型-保序严格部分一一变换半群.对任意的1≤kn-1,0≤rn-1,记OIn,rk={αOInk:|im(α)|≤r}为半群OInk的双边理想.通过对秩为r的元素和格林关系的分析,分别获得了半群OOIn,rk的极小生成集和秩.进一步确定了当0≤lr时,半群OIn,rk关于其理想OIn,lk的相关秩.  相似文献   

2.
本文考虑了如下的一类平面四次复Lotka-Volterra系统的可线性化问题=x(1-a30x3-a21x2y-a12xy2-a03y3),=-y(5-b30x3-b21x2y-b12xy2-b03y3).该系统为四次齐次多项式扰动下的具有$1:-5$线性项的复Lotka-Volterra系统,给出了该系统可线性化的充分必要条件.  相似文献   

3.
图分解问题已在很多邻域中得到了广泛的应用。用P5表示5个顶点的路,C5表示5个顶点的圈,本研究讨论了完全图Kn分解成5个顶点的路P5和圈C5的存在性,给出完全图Kn存在{P5,C5}-强制分解的充分必要条件是n≥7(n≠8),以及完全图Kn存在{P5,C5}-分解的充分必要条件是n≥5(n≠6)。  相似文献   

4.
 介绍了加权弱Hardy空间的相关概念,在其原子分解的基础上,研究了Marcinkiewicz积分在弱Hardy空间的加权有界性,借助于权函数的性质及不等式估计,得到了Ω满足Lipα(0<α≤1)条件时,Marcinkiewicz积分在加权弱Hardy空间WHΩ1(Rn)上是有界的结果.  相似文献   

5.
线性交换子的加权估计   总被引:2,自引:2,他引:0  
 多线性交换子Tb(f)(x)=∫Rni=1m(bi(x)-bi(y))k(x,y)f(y)dyLp(Rn)(1K是一个标准的Calderón-Zygmund核.主要研究交换子Mf(x)=supx∈QQ|f(y)|dy,其中fLloc(Rn),xRn,Q是任何包含x的方体,并用Sharp极大估计得到了该多线性交换子在Herz空间的一个加权有界性.  相似文献   

6.
将 4-(2-吡啶基) 苯乙酮与 3-醛基-7-N, N-二乙基氨基香豆素缩合反应, 获得了具有α,β-不饱和酮结构的C,N-配体(1) ,再将该配体与[Ru(cycme) Cl2]2和 2,2''-二联吡啶反应, 得到了具有 α,β-不饱和酮的环金属钌配合物(2) ,并通过1H NMR, MS 和紫外-可见吸收光谱表征了其结构.结果表明: 该配合物的最大吸收峰位于 475 nm,其摩尔消光系数达到 5.2×104 mol-1 ·L·cm-1 ; 在 PBS 缓 冲溶液中, 可选择性识别 HSO3-, 对 HSO3-检测限为37 μmol /L.  相似文献   

7.
采用水热法合成了含混合配体的铜配合物[CuClPhen]+·[HL]-·2H2O(HL=5-硝基间苯二甲酸,Phen=1,10-菲咯啉),其结构由单晶X射线晶体学确定。标题化合物在三斜空间群P-1的晶体化合物。标题化合物的晶体数据:C32H24ClN5CuO8,Mr = 704.54,a = 10.4044(5),b = 12.3912(9),c = 12.4632(9)Å,α = 73.859(6),β = 85.036(5),γ = 78.202(5)°,V = 1510.09(17) Å3,Z = 2, T = 293(2) K,Dc = 1.549 g/cm3,μ(Mo) = 0.874 mm-1,F(000) = 720.0,R = 0.0554,wR = 0.1434,GOF = 1.098。当用作超级电容器电极材料时,所制备的配合物具有高比电容、良好的循环稳定性和优良的倍率性能。在1mol/L KOH溶液中,最大比电容可达到69 F/g。在2 A/g电流密度下,10000次循环后比电容保持率为72%。标题化合物是一种潜在的红色光致发光材料。  相似文献   

8.
研究了一类三圈图Tm,k,rn,p,q的Merrifield-Simmons指标和Hosoya指标,根据Cp上两接点uv之间的距离,给出了该类三圈图关于这两种指标的排序  相似文献   

9.
 去掉了已有文献中的条件:"对任意子列{xni} {xn},当‖Tnixni-xni0时就有‖Txni-xni0"后,研究了Banach空间中渐近拟非扩展型映象不动点的迭代逼近问题;所得结果推广和发展了已有文献中的成果.  相似文献   

10.
引入对数凹函数熵的Busemann-Petty问题,即对于2个Rn上的偶的对数凹函数fg, 且fg具有正的、有限的积分,假设∫RnHf(x)dx≤RnHg(x)dx对于任意i维子空间H均成立,是否能够得到Ent(f)≥Ent(g).得到了该问题的部分解答, 为解决凸体上的低维Busemann-Petty问题提供了一种新的途径.  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.
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   

18.
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   

19.
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   

20.
For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the  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