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1.
证明了森或树的任一正特征值λq-i(i=q-1,q-2,…,0)满足λq-i≥2cos[tiπ/(2ti+1)](ti=[[2q/(i+1)]/2]),并指出这个下界对于边独立数为q的森或者顶点数为n、边独立数为q的森是最好可能的;对于边独立数为q的树或者顶点数为n、边独立数为q的树当i=q-2,q-3,…,q-[(q+1)/2]或当i=q-[(q+1)/2]-1,q-[(q+1)/2]-2,…,1(q0(modi+1))时,这个下界是最好可能的  相似文献   

2.
设X为p-一致平滑的Banach空间,p∈[1,2],T:D(T)→X是局部Lipschitz和严格增殖算子,本文给出了非线性方程TX=Y的解的迭代逼近,所得结果推广了文[1]的主要结果。  相似文献   

3.
设X为p-一致平滑的Banach空间,p∈[1,2],T:D(T)→X是局部Lipschitz和严格增殖算子,本文给出了非线性方程TX=Y的解的迭代逼近,所得结果推广了文[1]的主要结果。  相似文献   

4.
在L~p(1<p<2)空间中讨论了非线性方程X+Tx=f(其中T为增生算子)的解的选代逼近问题,从而将Chidume~[2,3]的结果作了推广。  相似文献   

5.
对cos(ix)用有理逼近Rnm(-x ̄2)(i ̄2=-1)构造了隐式辛算法,特别对cos(ix)的Padé逼近的一个结果:[o/2m]逼近是绝对稳定的。得到了对应于有理逼近R_(22)(-x ̄2)的时间方向四阶精度算法,讨论了它们的稳定性区域。证明了时间方向六阶和八阶精度算法具有宽的稳定性区域。  相似文献   

6.
本文研究了关于[x]的两个不等式;得到对一切的自然数n有[x+y+nz]+[x+ny+z]+[nx+y+z]≤[(n+2)x]+[(n+2)y]+[(n+2)z]+2;当且仅当1≤n≤4时,有[x]+[y]+[z]+[x+ny+z]+[x+y+nz]+[nx+y+z]≤[(n+3)x]+[(n+3)y]+[(n+3)z]+1。  相似文献   

7.
从易得的原料出发,采用合理的步骤,合成出2种新型品成色剂3-苯基-6-甲基1H-吡唑并[5,1-C][1,2,4]三唑(Ⅲ)和3-十五烷基-6-甲基-1H-吡唑并[5,1-C][1,2,4]三唑(Ⅳ)。试验了Ⅱ与硫酰氯的反应,得到预期的7-氯衍生物(7-Cl-Ⅱ)。  相似文献   

8.
报道了以三(3-胺基丙基)胺(trpn)在Cd(ClO4)2·6H2O存在下,分别与2,6-二甲醛基-4-甲苯酚(dmp)及2,6-二甲醛基-4-溴苯酚(dbp)的钠盐发生[2+2]和[2+3]的希夫碱缩合反应,合成了两个新的双核镉(Ⅱ)多氮穴合物[Cd2L1]ClO4和[Cd2L2(H2O)]·2ClO4·0.5CH3OH.晶体结构表明:穴合物中两个镉(Ⅱ)原子均处于相似的环境,每个镉(Ⅱ)原子的配位数均为7(N4O3),处于变形十面体的中心,穴合物[Cd2L1]+中的两个镉(Ⅱ)通过三个酚氧原子为桥;穴合物[Cd2L2(H2O)]2+中的两个镉(Ⅱ)则是通过二个酚氧原子和外加一个参与配位的水分子为桥连接起来.并进一步比较了[Cd2L1],[Cd2L2(H2O)]2+及另两个相似的镉(Ⅱ)双核穴合物[Cd2L3]+,[Cd2L4]+的稳定性大小.  相似文献   

9.
合成和表征了2个新的双金属配合物-[Cu(SIH)]2·1/2%H2O和[Co(SIH)]2·1/2H2O,[SIH](2-)代表水杨醛异烟酰腙的脱氢阴离子],其变温磁化率测定指出,两配合物双核单元中金属离子间存在着铁磁性相互作用。  相似文献   

10.
本文给出了由Toda 谱V(1)的同伦群πV(1)确定出它的自映射群[ΣV(1),V(1)]的一般方法,并且由πV(1)的已知结果确定了[ΣV(1),V(1)]在次数< 2(p2 + 2p)(p- 1)- 5 时的全部Zp 基元,其中p≥5 是素数  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.
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   

14.
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   

15.
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   

16.
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   

17.
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   

18.
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   

19.
Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of  相似文献   

20.
<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with  相似文献   

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