On the Moments of Overflow and Freed Carried Traffic for the GI/M/C/0 System

In circuit-switched networks call streams are characterized by their mean and peakedness (two-moment method). The GI/M/C/0 system is used to model a single link, where the GI-stream is determined by fitting moments appropriately. For the moments of the overflow traffic of a GI/M/C/0 system there are efficient numerical algorithms available. However, for the moments of the freed carried traffic, defined as the moments of a virtual link of infinite capacity to which the process of calls accepted by the link (carried arrival process) is virtually directed and where the virtual calls get fresh exponential i.i.d. holding times, only complex numerical algorithms are available. This is the reason why the concept of the freed carried traffic is not used. The main result of this paper is a numerically stable and efficient algorithm for computing the moments of freed carried traffic, in particular an explicit formula for its peakedness. This result offers a unified handling of both overflow and carried traffics in networks. Furthermore, some refined characteristics for the overflow and freed carried streams are derived.     

Estimating a reduced rank regression model for non-normal variables

A method using third order moments for estimating the regression coefficients as well as the latent state scores of the reduced-rank regression model when the latent variable(s) are non-normally distributed is presented in this paper. It is shown that the factor analysis type indeterminacy of the regression coefficient matrices is eliminated. A real life example of the proposed method is presented. Differences of this solution with the reduced-rank regression eigen solution are discussed.     

Radiative lifetimes in Ce I and Ce II

New radiative lifetime measurements based on time-resolved laser-induced fluorescence techniques are reported for 18 even-parity levels belonging to the 4f5d^26p and 4f ²5d ² configurations of Ce I and 6 even-parity levels belonging to the 5d^26s, 4f5d6p, and 4f6s6p configurations of Ce II. Free neutral and singly ionized cerium atoms were produced by laser ablation. The Ce I and Ce II levels range in energy from 26 545 to 29 102 cm^-1, and 42 573 to 48 152 cm^-1, respectively. Received 25 September 2002 Published online 4 March 2003     

190区超形变核中转动带的组态结构

通过系统研究A～190区超形变核中转动带的转动惯量、角动量顺排、旋称分裂随转动频率的变化规律, 结合我们用处理对力的粒子数守恒方法的计算结果, 对A～190区所有转动带的组态结构给出了一个整体的描述. 绝大多数超形变带都建立在强耦合轨道上, 例如中子[512]5/2, [624]9/2. 少数超形变带则建立在高j闯入轨道上, 即中子[761]3/2, [752]5/2. 根据我们提出的组态结构所进行的理论计算结果表明, A～190区所有转动带的一般行为、反常变化和带交叉都得到了满意的解释.     

利用场发射显微镜研究O2对单壁碳纳米管场发射的影响

利用场发射显微镜和四极质谱计研究了充入高纯O2的四极质谱和O2对单壁碳纳米管场发射的影响.单壁碳纳米管经过约1000℃的热处理得到清洁态场发射像后，充入O2，分别测量了O2吸附和脱附后场发射的I V特性.实验观测到在单壁碳纳米管上O2的吸附使场发射电流减小，说明逸出功增加.在10-4Pa的O2压强下对单壁碳纳米管进行约1000℃的热处理，可以产生氧化刻蚀作用，观测到场发射像的变化，并测量了氧化刻蚀产生的I V特性变化. 关键词： 单壁碳纳米管 场发射显微镜 场发射 四极质谱     

Heterochain model for simultaneous long‐chain branching and crosslinking. III. Multicomponent polymerization

The matrix formula developed in the context of heterochain theory, M?_w = M?_wp + WF ( I ? M )^?1 S , was applied to describe the molecular weight development during free‐radical multicomponent polymerization. All of the required probabilistic parameters are expressed in terms of the kinetic‐rate constants and the various concentrations associated with them. In free‐radical polymerization, the number of heterochain types, N, needs to be extrapolated to infinity, and such extrapolation is conducted with only three different N values. This matrix formula can be used as a benchmark test if other approximate approaches can give reasonable estimates of the weight‐average molecular weights. The moment equations with the average pseudo‐kinetic‐rate constants for branching and crosslinking reactions may provide poor estimates when the copolymer composition drift during polymerization is very significant. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 2801–2812, 2004     

基于Apollo信号控制台的NQR炸药探测方法

介绍了一种基于Apollo信号控制台的核四极矩共振（NQR）炸药探测方法，描述了系统的结构组成、工作原理和实现方法，并给出了对RDX的测试试验结果. 试验表明该方法可实现对RDX信号的探测.     

Quadrupole interactions at 57Fe and 119Sn in 3d-metal antimonides

3d-metal antimonides: Fe_1+x Sb, N_+x Sb, Co_+x Sb and the (Ni_1?y Fe _y )Sb solid solution have been studied by the Mössbauer effect method at ⁵⁷Fe and ¹¹⁹Sn. It was found that the quadrupole interactions at the Fe and Sn nucleus in 3d-metal antimonides are very sensitive to the filling of different crystallographic sites with metal atoms. The metal atoms in trigonal-bipyramidal sites have a strong effect on the quadrupole splitting of ¹¹⁹Sn. They are nearest to anions (Sb or Sn) with the typical axial ratio of c/a = 1.25. The QS(x) dependence of ¹¹⁹ Sn in 3d-metal antimonides in the 0 ≤ x ≤ 0.1 concentration range can be used to determine x – the concentration of transition metal excess relative to the stoichiometric composition.