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1.
A生成Banach空间X上的指数有界cosine函数C(t),本文讨论了在满足(Z)条件的乘积扰动下C(t)的范数连续性,局部LipschiZ连续性仍保持不变,得到了一个逼近结果.  相似文献   

2.
研究二阶迭代微分方程x^.. g(x(x))=p(t)T-周期解的存在性,其中,g,p均连续,p(t T)=p(t),且∫o^Tp(t)dt=0。主要方法是先估计解的先验界,再用Mawhin连续性定理得出周期解的存在性。在对g要求更宽松的条件下,得到了方程T-周期解存在的充分条件。  相似文献   

3.
利用Mawhin的连续性定理及迭合度理论,讨论了共振条件下分数阶微分方程cDβ0+α(t)cDα0+x(t)=f(t,x(t),cDβ0+α(t),cDα0+x(t)),t∈[0,1] cDα0+x(0)=0,x(1)=sum from m to i=1 aix(ζi)多点边值问题解的存在性,得到解存在的充分条件,推广了整数阶微分方程共振问题已有的结果.  相似文献   

4.
讨论可加稳定分量过程局部时的存在性和连续性,证明了在N>max1≤k≤N∑hl=1dlαlk条件下,N指标可加稳定分量过程X={X(t);t∈RN }a.s.存在关于时间变量t和空间变量x联合连续的局部时.  相似文献   

5.
研究二阶迭代微分方程 x+g(x(x) ) =p(t) T-周期解的存在性 ,其中 g,p均连续 ,p(t+T) =p(t) ,且∫T0p (t) dt=0 .主要方法是先估计解的先验界 ,再用 Mawhin连续性定理得出周期解的存在性 .在对 g要求更宽松的条件下 ,得到了方程 T-周期解存在的充分条件 .  相似文献   

6.
在连续时间条件下消费和投资最优准则研究   总被引:1,自引:0,他引:1  
作为在数理金融中的问题maxE{∫0^TU(C,t)dt},在一定条件下可得最优消费和投资组合准则的显式解.但对它作些演绎,亦能在更好条件下得到最优显式解.  相似文献   

7.
基于正则蕴涵算子分析了三Ⅰ算法的连续性与逼近性问题,指出在模糊连续输入的条件下,RL、RG、RⅡ型三Ⅰ算法均具有连续性与逼近性,并指出了R0型三Ⅰ算法具有连续性与逼近性的条件是↓Ax∈X,A^*(x)∧A(x)〉1/2成立。  相似文献   

8.
将二维Hilbert编码和Z编码拓展到以尺度维作为第三维的三维填充曲线: 多尺度Hilbert曲线和Z曲线。在多尺度数据条件下, 这两种曲线能够提高空间填充曲线的空间连续性, 适应多尺度的需求。依托四叉树模型, 将多尺度的Hilbert曲线与按照相同思路设计的多尺度Z曲线进行两类对比试验, 验证了多尺度Hilbert曲线相对于Z曲线在空间连续性方面的优势, 提高的比例在15%~30%之间。  相似文献   

9.
将测度论中集函数的σ加性和上、下连续性推广为广σ加性和广上、下连续性,减弱了原来命题的条件,得到了σ可加性公理的四个新的等价条件  相似文献   

10.
在改进集定义的序关系下,本文建立了广义弱向量平衡问题解的线性标量化特征,并通过引入集值映射的一种新的严格伪单调性得到了广义弱向量平衡问题解的连续性(包括上半连续性和下半连续性)结果。  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   

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