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1.
在Z-P-S空间中,利用拓扑度方法研究非线性算子方程Tx=μx(其中μ≥1)和Tx=μx+p(其中μ≥1)解的存在性,得到了一些新的定理和推论.  相似文献   

2.
逻辑方程F=G的解集研究及其应用   总被引:4,自引:0,他引:4  
为了使解非0型、非1型的逻辑方程F=G更加灵活、多样化。文章给出了逻辑方程F=G、F G-=1、FG-=1的解集关系定理,将逻辑方程F=G化为0型或1型逻辑方程的方法以及相应的推论,并给予证明。得到了若F G-=1和FG-=1的解集分别为S1、S2,则F=G的解集为S1-S2,若F G=0和F- G-=0的解集分别为S3、S4,则F=G的解集为S3 S4,以及若F.G=1和F.-G-=1的解集分别为S3′、S4′,则F=G的解集S3′ S4′为的结论.从而可应用结论解非0型、非1型和某些有关的逻辑方程。  相似文献   

3.
环面上Van der Pol方程的研究   总被引:1,自引:0,他引:1  
本文对环面上Van der Pol方程 dx/dt=sin y,dy/dt=-sinx μsin 3y(x mod 2π,y mod 2π)的极限环问题进行研究,得到下述两个结果定理1 环面上Van der Pol方程对于μ=0,μ≤-1和μ≥1不存在第一类极限环。定理2 环面上Van der Pol方程对于非零的小参数μ至少存在两个第一类极限环。  相似文献   

4.
本文给出了拓广的两类特殊广义Riccati方程的求解法,并提供了通积分的表达式。 文[1]、[2]、[3]、[4]指出Liouville(刘继尔)已证明Riccati(黎卡提)方程 y~1=P(x)y~2+g(x)y+f(x)在一般情况下,不能用初等积分法求解。 我们仿照文[3]的方法,主要指出了两类特殊的广义Riccati方程是可积的,并给出了通积分的表达式,文中所得的定理及推论推广了文[1]、[2]、[3]、[4]的有关结果,对文献中的某些方程的求解显得更加简捷了。  相似文献   

5.
本文证明了具有周期系数Riccati方程周期解的三个存在定理。其中定理1和定理2是在与文[1]定理3·3相同的假设条件下,得出能区分周期解存在个数的进一步结果,从而推广了文[1]定理3·3;定理3给出了判别周期解存在的一个新的充分条件,解决了文[1]中未解决的某些问题。  相似文献   

6.
给出了一类一阶非线性微分方程:y′=(x)y+q(x)y^u+r(x)+^n∑i=2fi(x)yi的较为广泛的一个封闭可积条件,该条件推广和统一了文献1中的定理1和定理2,特别指出近年来关于著名的Riccati方程和Abei方程可积性的一批最新结果都是它的特例。  相似文献   

7.
在求解非线性算子方程F(x)=0时,若导数不存在,则可用修正牛顿法代替牛顿法进行迭代,并用优函数的方法证明了它的收敛性,从而给出了收敛性判断的条件、收敛性证明及迭代法收敛球半径和方程具有唯一解的球的半径估计,并由此得到了几个推论.主要定理推广了相关文献的结果.  相似文献   

8.
通过定理2和定理3,建立了Riccati方程和二阶齐线性微分方程的关系,并利用二阶齐线性微分方程的幂级数解表示相应Riccati方程的解。  相似文献   

9.
根据m(m为大于1的奇数)次代数方程的性质,得到了一类奇次周期Riccati型方程3个周期解的存在性和稳定性判别准则,推广了周尚仁等关于阿贝尔方程周期解的一些结果,且给出了定理实现的例子。  相似文献   

10.
应用Green函数及其梯度估计,结合迭代技巧,考虑了如下高维Riccati方程-Δu=uq,x∈RN+,u=μ,x∈R_+~N的可解性,其中q1,μ是边界R_+~N上的Radon测度.主要结果建立了解的存在性,同时还得到了解及其梯度的逐点估计.  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.
<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   

20.
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