弱Orlicz鞅空间的原子分解

本文对于几种类型的弱Orlicz 鞅空间建立了强型和弱型的原子分解定理, 证明了这些空间上的次线性算子的有界性以及这些空间彼此的连续嵌入关系. 弱Orlicz 空间是一类拟Banach 空间, 有关结论扩展了现有的关于Orlicz 空间和弱型Lorentz 空间的相关结论.     

On singular Lüroth quartics

Plane quartics containing the ten vertices of a complete pentalateral and limits of them are called Lüroth quartics.The locus of singular Lüroth quartics has two irreducible components,both of codimension two in P14.We compute the degree of them and discuss the consequences of this computation on the explicit form of the Lüroth invariant.One important tool is the Cremona hexahedral equations of the cubic surface.We also compute the class in M 3 of the closure of the locus of nonsingular Lüroth quartics.     

McKay箭图与覆盖空间

本文研究在自然扩张和嵌入下特殊线性群和一般线性群的有限子群的McKay 箭图间的关系. 我们证明在特定条件下, 一般线性群GL(m;C) 的有限子群G的McKay 箭图是其正规子群G∩SL(m;C)的McKay 箭图的正则覆盖, 而当把G 嵌入SL(m+1;C) 时, 新的McKay 箭图由在原来的McKay 箭图的每一顶点加上一个由其Nakayama 平移到其自身的箭向得到. 作为例子, 我们指出如何用这些方法得到一些有趣的McKay 箭图.     

包含$l^{\beta}(0<\beta<1)$渐近等距翻版的有界线性算子空间

Assume X is a normed space,every x ＊ ∈ S（X＊） can reach its norm at some point in B（X）,and Y is a β-normed space.If there is a quotient space of Y which is asymptotically isometric to l β,then L（X,Y） contains an asymptotically isometric copy of l β.Some sufficient conditions are given under which L（X,Y） fails to have the fixed point property for nonexpansive mappings on closed bounded β-convex subsets of L（X,Y）.     

非紧L-凸度量空间中的一个新的不动点定理及其对极大极小不等式和鞍点的应用

In this paper,a new fixed point theorem is established in noncompact complete Lconvex metric spaces.As applications,a maximal element theorem,a minimax inequality and a saddle point theorem are obtained.     

全函数空间和置换空间的一些性质

In this paper, an equivalent relation among the reflexivity, weak sequential completeness and bounded completeness in full function space is given. Some results on weakly sequential compactness of subset and the property （u） in substitution spaces are obtained.     

有限重数的Dirichlet移位

In this paper, we show that a multiplication operator on the Dirichlet space D is unitarily equivalent to Dirichlet shift of multiplicity n ＋ 1 （n ≥ 0） if and only if its symbol is c zn＋1 for some constant c. The result is very different from the cases of both the Bergman space and the Hardy space.     

Decoherence effects in Bose–Einstein condensate interferometry I. General theory

The present paper outlines a basic theoretical treatment of decoherence and dephasing effects in interferometry based on single component Bose–Einstein condensates in double potential wells, where two condensate modes may be involved. Results for both two mode condensates and the simpler single mode condensate case are presented. The approach involves a hybrid phase space distribution functional method where the condensate modes are described via a truncated Wigner representation, whilst the basically unoccupied non-condensate modes are described via a positive P representation. The Hamiltonian for the system is described in terms of quantum field operators for the condensate and non-condensate modes. The functional Fokker–Planck equation for the double phase space distribution functional is derived. Equivalent Ito stochastic equations for the condensate and non-condensate fields that replace the field operators are obtained, and stochastic averages of products of these fields give the quantum correlation functions that can be used to interpret interferometry experiments. The stochastic field equations are the sum of a deterministic term obtained from the drift vector in the functional Fokker–Planck equation, and a noise field whose stochastic properties are determined from the diffusion matrix in the functional Fokker–Planck equation. The stochastic properties of the noise field terms are similar to those for Gaussian–Markov processes in that the stochastic averages of odd numbers of noise fields are zero and those for even numbers of noise field terms are the sums of products of stochastic averages associated with pairs of noise fields. However each pair is represented by an element of the diffusion matrix rather than products of the noise fields themselves, as in the case of Gaussian–Markov processes. The treatment starts from a generalised mean field theory for two condensate modes, where generalised coupled Gross–Pitaevskii equations are obtained for the modes and matrix mechanics equations are derived for the amplitudes describing possible fragmentations of the condensate between the two modes. These self-consistent sets of equations are derived via the Dirac–Frenkel variational principle. Numerical studies for interferometry experiments would involve using the solutions from the generalised mean field theory in calculations for the stochastic fields from the Ito stochastic field equations.     

Z箍缩等离子体X射线凸晶谱仪

 针对波长为0.3~0.5 nm的喷气箍缩等离子体X射线诊断,研制了一种适用的高空间分辨的晶体谱仪。色散元件采用云母（002）凸面晶体,布拉格角为37°,信号采用X射线胶片进行接收,有效接收面积为30 mm×80 mm。物理实验在“阳”加速器装置上进行,胶片获得了氩喷气K,L壳层光谱信号,其光谱范围较宽,为0.31~0.40 nm。经解谱发现,类氦谱线有明显的基底,用最小二乘法拟合包络曲线去噪处理后,得到类氦谱线光谱分辨力为200~300。实验结果表明,该谱仪获得的X射线测量值与理论值相符,适合喷气箍缩等离子体X射线光谱的诊断。     

高压直流连续波光阴极注入器中发射度补偿

空间电荷效应是引起发射度增长的主要因素,特别是在高压直流连续波光阴极注入器中。分析了高压直流连续波光阴极注入器中线性空间电荷力的特点及其对电子束横向发射度的影响,并从理论上解析地研究了螺线管发射度补偿的原理及特点。最后利用Parmela程序对中国工程物理研究院高压直流连续波光阴极注入器的发射度补偿作了模拟计算。结果表明,束团电荷量为80 pC的电子束在350 keV高压直流电子枪出口处的横向归一化发射度为5.14 mmmrad,经过螺线管补偿后,其最小横向发射度变为1.27 mmmrad。电子束的发射度得到了很好的补偿。