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1.
设a_i(i=1,2,3)为三角形ΔA_1A_2A_3的边长,S为ΔA_1A_2A_3的面积,λ_j(j=1,2,3)为任一组正数.作者将Oplsonbeim三角形不等式推广到n维欧氏空间E ̄n中的n维单形,从而获得了n维单形的Oppenbeim不等式这里V是n维单形A_1A_2…A_(n+1)的体积,V_i为顶点A_i所对之侧面的面积,λ_i为任意一组正数.  相似文献   

2.
X′=(x1,x2…,xn),问在∑ni=1x2i≤1条件下,a3=∑n-2i=1xixi+2,a5=∑n-1i=1xixi+1,当X取遍∑ni=1x2i≤1上的点,(a3,a5)在平面上构成怎样的图形?该文对n=4给出解析解  相似文献   

3.
若X′=(x1,x2,…,xn),问在ni=1x2i≤1条件下,a3=n-2i=1xixi+2,a5=n-1i=1xixi+1,当x取遍ni=1x2i≤1的点,(a3,a5)在平面上构成怎样的图形.该文对n=5给出解析解.  相似文献   

4.
一类食饵具有常数存放率的n次Kolmogorov系统的极限环   总被引:3,自引:0,他引:3  
本文讨论一类食饵具有常数存放率的n次Kolmogorov微分系统其中a_0,a_2,b_1,和b_2是正常数;F是负常数;a_1和a_3不定号,得到下列结论:l:当A_1-2A_3+m>0时,系统(1)在第一象限存在唯一稳定的极限环2:当A_1-2A_3≤0时,系统(1)在第一象限全局稳定  相似文献   

5.
X'=(x1,x2,…,xn),问在Σi=1↑nxi^2≤1条件下,a3=Σi=1↑n-2xixi+2,a5=Σi=1↑n=1xixi+1,当X取遍Σi=1↑nxi^2≤上的点,(a3,a5)在平面上构成怎样的图形?该文对n=4给出解析解。  相似文献   

6.
分担两个值的亚纯函数   总被引:3,自引:0,他引:3  
该文主要证明如下的定理1  设f 和g 为非常数亚纯函数,a1 , …,an 为互异复数,若(i) f 和g CM 分担a1 ,a1 ,(ii) δ( ∞,f)= δ( ∞,g) =1 ,(iii) a3 ,…,an 为f 的亏值,满足nj=3δ(aj ,f) > n - 2n ,则(a) 当n = 3 时,有f ≡g 或(f - a3)(g + a3 - a1 - a2) ≡(a3 - a1)(a2 - a3)且有δ( a3 , f) = 1, δ(a1 + a2 - a3 , g) = 1,(b) 当n > 3 时,有f ≡g 。  相似文献   

7.
次Hermite矩阵的次正定性   总被引:13,自引:1,他引:13  
若n阶次Hermite矩阵A,对任意非零向量X'=(x_1,x_2,…x_n)∈R ̄n,有AX>0,则称次Hermite矩阵A是次正定的.给出了判定次Hermite矩阵次正定的几个充要条件:定理n阶次Hermite矩阵A是次正定的,当且仅当下列条件之一成立:(l)Hermite矩阵JA是正定的;(2)存在n阶可逆复矩阵P,使AP=J;(3)次Hermite矩阵A的4k阶,4k十互阶下次主子式为正,4k+2阶,4k+3阶下次主子式为负;(4)存在n阶可逆复矩阵P,使其中λ_i>0,i=1,2,…,n。  相似文献   

8.
陈兰荪等在第二届中国生物数学学术会议上提出了生物动力学系统中研究的11个问题。作者所研究的是第11个问题,生物化学中两分子饱和反应。其数学模型为x=J_1(1+x+y+Ax ̄2)-x(1+x+y+Ax ̄2)-Bxy;y=J_2(1+x+y+Ax ̄2)-Bxy.其中:J_1、J_2、A、B为非负常数,当J_1-3J_2<-[1+Bx+(B+1)y]/(1+Ax)时,该模型在第一象限内至少存在一个极限环;当J_1<J.x<y,B>l且x>a时,该模型在第一象限内存在唯一的极限环。其中a<0为方程p(x=)=0的最大负实根.  相似文献   

9.
图的圈长分布和圈长分布唯一的图   总被引:1,自引:0,他引:1  
阶为n的图G的圈长分布是指序列(c1,c2,…,cn),其中ci是G中长为i的圈数.若不存在,使G’与G有相同的圈长分布,则称图G是圈长分布唯一图.本文确定了Kn-A(|A|=j,n≥|A|+3)的最小、最大的4圈和5圈数.证明了当n≥9时,Kn-A(|A|=4)以及当n≥14时,Kn-A(|A|=5)都是圈长分布唯一图.  相似文献   

10.
运用文献[1]的结果建立了如下的渐进展开式:n∫π/20sinnxdx~π2∞i=0aini其中,al由下面的递推公式所决定:li=0aibl-i=(-1)l1/2(1/2-1)…(1/2-l+1)l!,a0=1,l=1,2,3式中:b0=1,b1=a1,bi+1=a1+i1!a2+i(i-1)2!a3+…+i(i-1)…(i-i+2)(i-1)!ai+i!i!ai+1,i>1这个新递推公式的作用是简化了系数计算的复杂性。此外,还给出了有关的Walis公式渐进性的应用。  相似文献   

11.
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   

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.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

14.
Instead of following Fock’s expansion,we solve the Schrodinger equation for some quantum mechanical manybody systems such as electrons in atoms and charged excitons in quantum wells in a similar way in hyperspherical coordinates by expanding the wave functions into orthonormal complete basis sets of the hyperspherical hannonics(HHs)of hyperangles and generalized Laguerre polynomials(GLPs)of the hyperradius.This leads the equation to  相似文献   

15.
Future mobile communication systems aim at providing very high data transmission rates, even in high-mobility scenarios such as high-speed wheel-track trains, maglev trains, highway vehicles, airplanes, guided missiles or spacecraft. A particularly important commercial application is the strong and increasing worldwide demand for high- speed broadband wireless communications (up to 574.8 km/ h test speeds or 380 km/h commercial speeds) in railways, providing data, voice and video services for applications such as onboard entertainment services to passengers, train control, train dispatch, train sensor status handling and sur- veillance. In such high-mobility scenarios, there are a number of communication challenges, including fast hand- over, location updating, high-speed channel modeling, estimation and equalization, anti-Doppler spreading tech- niques, fast power control, and dedicated network architec- ture. Because signal transmission in very high-speed scenarios will inevitably experience serious deterioration, it is imperative to develop key broadband mobile communi- cation techniques for such high-speed vehicles.  相似文献   

16.
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.
Being the primary media of geographical information and the elementary objects manipulated, almost all of maps adopt the layer-based model to represent geographic information in the existent GIS. However, it is difficult to extend the map represented in layer-based model. Furthermore, in Web-Based GIS, It is slow to transmit the spatial data for map viewing. In this paper, for solving the questions above, we have proposed a new method for representing the spatial data. That is scale-based model. In this model we represent maps in three levels: scale-view, block, and spatial object, and organize the maps in a set of map layers, named Scale-View, which associates some given scales.Lastly, a prototype Web-Based GIS using the proposed spatial data representation is described briefly.  相似文献   

19.
Various applications relevant to the exciton dynamics,such as the organic solar cell,the large-area organic light-emitting diodes and the thermoelectricity,are operating under temperature gradient.The potential abnormal behavior of the exicton dynamics driven by the temperature difference may affect the efficiency and performance of the corresponding devices.In the above situations,the exciton dynamics under temperature difference is mixed with  相似文献   

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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