Fissility effects on evaporation residue spin distributions

Based on a dynamical Langevin equation coupled with a statistical decay model, we calculate the spin distribution of evaporation residue cross sections of nuclei ¹⁹⁰Os and ²¹⁰Po which have the same neutron-to-proton ratio N/Z$N/Z$ but have a difference in fissility. We find that a large fissility enhances the sensitivity of the residue spin distribution to pre-saddle friction substantially. The results suggest that on the experimental side, to obtain accurate information of pre-saddle dissipation strength by measuring the evaporation residue spin distribution it is optimal to populate among various compound systems with equal N/Z$N/Z$ those with high fissility.     

Complex networks: Effect of subtle changes in nature of randomness

In two different classes of network models, namely, the Watts Strogatz type and the Euclidean type, subtle changes have been introduced in the randomness. In the Watts Strogatz type network, rewiring has been done in different ways and although the qualitative results remain the same, finite differences in the exponents are observed. In the Euclidean type networks, where at least one finite phase transition occurs, two models differing in a similar way have been considered. The results show a possible shift in one of the phase transition points but no change in the values of the exponents. The WS and Euclidean type models are equivalent for extreme values of the parameters; we compare their behaviour for intermediate values.     

A local-world heterogeneous model of wireless sensor networks with node and link diversity

In this paper, we present a novel local-world model of wireless sensor networks (WSN) with two kinds of nodes: sensor nodes and sink nodes, which is different from other models with identical nodes and links. The model balances energy consumption by limiting the connectivity of sink nodes to prolong the life of the network. How the proportion of sink nodes, different energy distribution and the local-world scale would affect the topological structure and network performance are investigated. We find that, using mean-field theory, the degree distribution is obtained as an integral with respect to the proportion of sink nodes and energy distribution. We also show that, the model exhibits a mixed connectivity correlation which is greatly distinct from general networks. Moreover, from the perspective of the efficiency and the average hops for data processing, we find some suitable range of the proportion p of sink nodes would make the network model have optimal performance for data processing.     

基于弱相干态光源的非正交编码被动诱骗态量子密钥分配

基于改造的弱相干态光源,提出了一种非正交编码被动诱骗态量子密钥分配方案.该方案不主动制备诱骗态,而是根据发送端探测器是否响应,将接收端的探测结果分为响应集合和未响应集合,以此分别作为信号态和诱骗态,并利用这两个集合来估计参量和生成密钥.数值仿真表明,非正交编码被动诱骗态方案的密钥生成效率和安全传输距离都优于现有的被动诱骗态方案,且性能非常接近主动无穷诱骗态方案的理论极限值;未响应集合对密钥生成的参与使方案性能免受发送端探测效率的影响,弥补了实际探测器探测效率低下的缺陷;由于不需要主动制备诱骗态,该方案实现非常简单,适用于高速量子密钥分配的场合. 关键词： 量子光学 量子密钥分配 被动诱骗态 密钥生成效率     

光参量荧光寿命分布

 根据荧光寿命定义和放大过程获得的增益方程,研究了新型非线性晶体BaAlBO₃F₂中三种不同的相位匹配模式下中心波长532 nm泵浦的参量荧光光子寿命的分布特性。结果表明,当注入单色信号光时,参量荧光寿命随泵浦光相位匹配角的增加由椭圆体分布变化为圆环体分布。采用宽带信号光时,则由分散分布改变为集中在近200 nm波长范围内分布,并随泵浦光相位匹配角的增加而逐步减小。考虑宽带泵浦光注入情况时,参量荧光寿命的分布范围由于相位匹配范围增加而随之扩展。     

Asymptotics for the Tail Probability of Random Sums with a Heavy-Tailed Random Number and Extended Negatively Dependent Summands

Let {X,X_k:k≥1} be a sequence of extended negatively dependent random variables with a common distribution F satisfying EX 0.Let r be a nonnegative integer-valued random variable,independent of {X,X_k:k≥1}.In this paper,the authors obtain the necessary and sufficient conditions for the random sums S_r =(?)X_n to have a consistently varying tail when the random number t has a heavier tail than the summands,i.e.,(P(Xx))/(P(r x))→0as x→∞     

关于f+a(f(k))n值分布的一个注记

本文研究亚纯函数的值分布问题.利用值分布理论,获得了一个带精简密指量的模分布的不等式,改进了Xu和Yang等人的结果.     

威布尔分布族刻度参数的经验Bayes检验函数的收敛速度

本文研究了在"加权线性损失"下,威布尔分布族刻度参数经验Bayes (EB)检验问题.利用概率密度函数的递归核估计,构造了刻度参数的经验Bayes检验函数,并获得了它的收敛速度,在适当的条件下,收敛速度的阶可任意接近O(n^-1),推广了文献的结果.最后给出一个有关本文主要结果的例子.     

Bayesian inference for Pr (Y

《Applied Mathematical Modelling》2014,38(5-6):1698-1709