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1.
利用了2-扭自由σ-素环的性质以及运用了替换法与线性化,讨论了σ-素环Jordan理想上满足一定条件的左(θ,θ)-导子. R为2-扭自由σ-素环,θ为R上的一个自同构,且与对合σ可交换,d为R上的左(θ,θ)-导子,J为R上的非零σ-Jordan理想.若d(J)=0,则d=0或JZ(R).所得的结果推广了Aydin. N和L. Oukhtite的相关结果.  相似文献   

2.
研究了形式如下的时标T上二阶非自治的p-Laplacian哈密顿系统{︱u~Δ(t)︱~(p-2)︱ u~Δ(t))~Δ=▽F(σ(t),u~σ(t)),Δ-a.e.t∈[0,T]_(Tk),u(0)-u(T)=0,u~Δ(0)-u~Δ(T)=0的边值问题,给出了该系统上的变分结构,同时证明了该系统的求解问题等价于求其相应泛函φ∈C~1(W_Δ,T~1,p(T,R~n),R)的临界点。  相似文献   

3.
针对滞后型泛函微分方程提出了拟一致Lipschitz指数稳定性概念。根据这一稳定性定义中的Lipschitz系数函数与指数函数的不同,可以分别包括已有的稳定、一致稳定、渐近稳定、指数渐近稳定等概念。因此,拟一致Lipschitz指数稳定又可以认为是上述稳定性的统一形式。一致Lipschitz稳定性也是一种新的稳定性,它包括稳定与一致稳定。但对非线性方程它并不被一致渐近稳定所蕴含。重点讨论了在条件:“函数f(t,)于R+×BnH的任一紧子集R+×BnH′(H′≤H)上满足:│f(t,φ1)-f(t,φ2)│≤E(H′)sup-r≤θ≤0│φ1(θ)-φ2(θ)│其中E(H′)≥0是仅依赖于H′的常数”下,利用Lipschitz泛函方法建立这种稳定性的充分及其必要条件。  相似文献   

4.
用半群理论和定义泛函的方法,考察无阻尼弱耗散抽象发展方程解的长时间动力学行为.在非线性项满足较弱的耗散型条件下,运用收缩函数理论和能量估计技巧验证了解半群的渐近紧性,得到了全局吸引子在空间V_θ×H×L_μ~2(R+;V_θ)中的存在性.  相似文献   

5.
使用密度泛函理论B3LYP方法,对两种双异戊烯基黄酮1R和2分子的几何结构、光谱、热力学性质进行理论计算研究,并基于Tomasi极化统一场模型(PCM)讨论溶剂效应.结果显示,1R和2分子在气相中的最低能量吸收波长分别为325.6和361.9nm,溶剂及其极性大小对1R和2分子的最低能量吸收波长影响很小.298K标准压力下,1R和2分子的气态标准摩尔热力学性质ΔfHθm分别为3455.51kJ/mol和3691.26kJ/mol,ΔfGθm分别为4028.23和4282.98kJ/mol,Sθm分别为834.90和834.97J/mol/K.  相似文献   

6.
令H为无限维复可分的Hilbert空间,H上有界线性算子的全体为B(H).用σ(T),σab(T)和σa(T)分别表示为算子T∈B(H)的谱集,Browder本质逼近点谱和逼近点谱.称算子T∈B(H)满足(R)性质,若σa(T)σab(T)=π00(T),其中π00(T)={λ∈iso σ(T)∶0相似文献   

7.
1.引言设 y 是 k×1随机向量,满足(Ⅰ){Ey=θ,Covy=σV,V≥0(非负定阵)已知。称(Ⅰ)为一般线性模型。设 q′y 是参数的线性函数 p′θ的线性估计量。关于 q′y 的允许性问题,C.R.Rao 在1975年的纪念 Wald 讲座[1]中叙述了如下定理:在平均二次损失函数  相似文献   

8.
设H为无限维复可分的Hilbert空间,B(H)为H上的有界线性算子的全体, T∈B(H)称为满足(R)性质,若σa(T)\σab(T)=π00(T),其中σa(T)和σab(T)分别表示算子T的逼近点谱和Browder本质逼近点谱,π00(T)={λ∈iso σ(T):0<dim N(T-λI)<∞}。 利用拓扑一致降标性质,首先给出了有界线性算子满足(R)性质的充要条件; 之后通过拓扑一致降标性质,得到了算子函数满足(R)性质的判定方法; 最后,上三角算子矩阵的(R)性质得到了研究。  相似文献   

9.
用边邻接指数预测链烷烃的热力学性质   总被引:4,自引:0,他引:4       下载免费PDF全文
用分子图理论和边价 (δei)建构新的连接性指数 (mE) ,籍以描述分子的大小及分支情况 .其中 ,0 E、1 E和碳原子的最大支化度 (δmax)或路径数P3 与 85种链烷烃的标准生成焓 (ΔfHθm)、标准熵 (Sθm)、标准生成自由能 (ΔfGθm)具有良好的相关性 :-ΔfHθm =5 1.12 0 7+2 .0 6 0 2 0 E+38.0 746 1 E+8.5 116δmax,R =0 .9979,Sθm =179.4143+35 .18840 E +2 8.0 3981 E - 1.0 0 3 4δmax,R =0 .9988,ΔfGθm =- 42 .4941+2 .5 330 0 E +9.38131 E +2 .12 5 9P3,R =0 .993 6 .  相似文献   

10.
正态分布参数函数的估计   总被引:1,自引:3,他引:1  
讨论正态分布N(μ,σ2)的参数(μ,σ2)的函数θ=exp{aμ ba2}(a≥0,b≥0)的估计问题,给出了θ的最大似然估计及矩估计.在μ和σ2的先验分布独立时,在损失函数L(θ,a)=(θ-a)2和L(θ,a)=(θ-1×a-1)2下给出Bayes估计和最小最大估计.  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.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

13.
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   

14.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  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.
本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。  相似文献   

18.
There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.  相似文献   

19.
20.
The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to  相似文献   

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