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1.
基于格林函数与并矢格林函数对电磁场进行讨论   总被引:1,自引:0,他引:1  
格林函数问题是讨论点源激励的辐射问题。本文从格林函数的概念出发,讨论了格林函数非齐次标量Helmholtz方程'2φ(r'→) k2φ(r'→)=-P(εr'→)的求解,同时利用并矢概念引入了并矢格林函数,对非齐次矢量方程××Ee→-k2Ee→=iωμJ→的求解进行了讨论,从结果来看,格林函数和并矢格林函数的引入,给复杂电磁问题的讨论带来了极大方便。  相似文献   

2.
采用准经典轨线方法,基于AP2势能面,我们系统研究了4.0 kcal/mol碰撞能条件下H+LiF→HF+Li和D+LiF→DF+Li反应的矢量相关性.我们获得了与产物矢量相关的三个产物极化分布函数P(θr),P(Φr)和P(θr,Φr).同时,我们研究并讨论了反应的两个极化微分反应截面.计算结果表明,HF和DF分子的转动角动量矢量j'对产物的转动极化具有很大的影响,反应的矢量相关性也较强的依赖于同位素效应.  相似文献   

3.
本证明了稳恒矢量场几个分区的唯一性定理,并由此定理给出了静电场中有电介质时D^→=ε。E^→。,稳恒磁场中有磁介质时H^→=B^→。/μ。成立,其场内介质需分别满足的条件。  相似文献   

4.
运用准经典轨线法在扩展的London-Eyring-Polanyi-Sato(LEPS)势能面上计算了初始碰撞能分别为55,65,75kJ/mol时O+CH4→OH+CH3反应的矢量相关情况.计算得到了广义极化微分反应截面、k-j′两矢量相关的p(θr)分布和k-k′-j′三矢量相关的p(φr)分布.对比不同碰撞能情况下的反应发现碰撞能在反应过程中所起的重要作用.  相似文献   

5.
本文给出:γ维流形上的对合,如果其不动点集F是有限个2n阶射影空间之并,那么若2n相似文献   

6.
对于给定的简单图G和正整数a1,a2,…,ak,G→(a1,a2,…,ak)vr(G→(a1,a2,…,ak)er)是指,对于V(G)(E(G))的任意k-染色,其中每个顶点(边)被用{1,…,k}的一个r-子集来染色,存在i∈{1,…,k}和一个阶为ai的完全子图,其中每个顶点(边)被一个包含颜色i的r-子集染色.本文在整数t>max{a1,a2,…,ak}的条件下,定义并研究下述集染色顶点(边)Folkman数:F(r)v(a1,a2,…,ak;t)=min{|V(G)|:G→(a1,a2,…,ak)vr且KtG}(类似地,F(r)e(a1,a2,…,ak;t)=min{|V(G)|:G→(a1,a2,…,ak)er且KtG}).  相似文献   

7.
对于给定的简单图G和正整数a1,a2,…,ak,G→(a1,a2,…,ak)vr(G→(a1,a2,…,ak)er)是指,对于V(G)(E(G))的任意k-染色,其中每个顶点(边)被用{1,…,k}的一个r-子集来染色,存在i∈{1,…,k}和一个阶为ai的完全子图,其中每个顶点(边)被一个包含颜色i的r-子集染色.本文在整数tmax{a1,a2,…,ak}的条件下,定义并研究下述集染色顶点(边)Folkman数:F(r)v(a1,a2,…,ak;t)=min{|V(G)|:G→(a1,a2,…,ak)vr且KtG}(类似地,F(r)e(a1,a2,…,ak;t)=min{|V(G)|:G→(a1,a2,…,ak)er且KtG}).  相似文献   

8.
本文讨论了半线性波动方程(2t-Δx)uε+F(εα|tuε|p-1tuε)=0(t,x)∈[0,∞[×R3uε|t=0=εU0(r,r-εr0),tuε|t=0=Ul(r,r-εr0)。当p>2,α=p-2时解在到达焦点(r0,0)前无穷远处的性态,其中F在R上是一致Lipschitz的。通过变量变换,将问题转化为负无穷远处的初、边值问题,证明解的存在唯一性,引入线性解讨论脉冲波在t→-∞的传播性态,并引入散射算子说明了脉冲波越过焦点的过程。  相似文献   

9.
设 Sm-1 是欧氏空间Rm 的单位球面.球面间的λ2 -特征映射g:Sm-1 →Sn-1 是各分量为2次齐次调和多项式的向量值函数G:Rm →Rn 在Sm-1 上的限制 [1,2] .下面,我们给出关于球面间λ2 特征映射的一些新结果和正交乘f:Rm×Rn →Rn(m 2)的一种简单表达式:定理1 设n 1 .存在满的λ2 特征映射(都记为g):(1)g:S2n 5 →Sr ,r = n2 6n -3或者n2 6n r 2n2 13n 19 .(2)g:S2n 6 →Sr ,r = n2 8n 4或者n2 8n 7 r 2n2 15n 26 .(3)g:S4n 3 →Sr ,r =2n2 3n -1或者2n2 3n 2 r 8n2 18n 8 .(4)g:S8n 7 →Sr ,r =4n2 …  相似文献   

10.
Eu~(3+)和CaWO_4共沉淀发光材料的制备及其发光性质   总被引:1,自引:0,他引:1  
通过共沉淀技术制备了稀土离子Eu3+和CaWO4共沉淀发光材料,并通过测试样品的红外光谱(IR)、激发光谱、发射光谱,研究了稀土离子Eu3+和CaWO4共沉淀发光材料的结构和发光性能.结果显示:反应产物中有CaWO4生成,在实验过程中加入的有机活性剂基本除净; 样品显示出Eu3+的特征发射光峰位于588nm和612nm,分别属于5D0→7F1和5D0→7F2跃迁,对应的主要激发光谱位置分别是363nm(7F0→5D4),383nm(7F0→5G2),395nm(7F0→5L6),414nm(7F0→5D3),465nm(7F0→5D2),536nm(7F0→5D1),560nm(7F2→5D1),585nm(7F0→5D0).说明稀土离子Eu3+在共沉淀材料中具有良好的发光性能,其含量为0.50%时发光性能最好.  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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