The International Atlas of Mars Exploration: The First Five Decades,Vol. 1, 1953 to 2003

With the recent advances in laser technology, experimental investigation of radiation reaction phenomena is at last becoming a realistic prospect. A pedagogical introduction to electromagnetic radiation reaction is given, with the emphasis on matter driven by ultra-intense lasers. Single-particle, multi-particle, classical and quantum aspects are all addressed.     

强磁场下He2++H(1s)的碰撞激发过程的态选择截面研究

强磁场下的重粒子碰撞激发过程是重要的非弹性碰撞过程, 但相关研究还几乎是空白. 应用经典蒙特卡洛的方法在得到无磁场下He²⁺+H(1s)的碰撞激发截面的基础上, 详细研究了不同强度的纵向和横向强磁场环境下到不同主量子数n和磁量子数m的碰撞激发过程的态选择截面. 同时用非微扰量子方法, 得到了强磁场下靶原子的能级, 并分析了其随磁场强度变化的原因. 对碰撞过程发现由于磁场的引入导致到不同m态的激发截面有较大的分离, 同时在较低入射能区的态选择截面变化行为与磁场方向有很大关系, 这与能级变化及横向强磁场所特有的抗磁项的相互竞争有密切联系. 通过对有关事例、径迹的分析, 解释了这些变化形成的原因. 也发现由于核的运动, 沿磁场方向的轨道角动量并非绝对守恒, 而有微小的变化. 关键词： 重粒子碰撞激发 经典蒙特卡洛模拟 强磁场 态选择截面     

两两NQD随机序列的完全收敛性

本文进一步研究了两两NQD随机序列的完全收敛性.在一些简单和弱的条件下获得了两两NQD随机序列的一些结果.所获结果不仅推广了Liu(2004)以及Gan和Chen (2008)的相应结果,而且还改进了他们的结论.     

Strong Laws of Large Numbers for Weighted Sums of Ч-mixing Sequence

In this paper, strong laws of large numbers for weighted sums of Ч-mixing sequence are investigated. Our results extend the corresponding results for negatively associated sequence to the case of Ч-mixing sequence.     

A Novel Method to Determine Basic Probability Assignment Based on Adaboost and Its Application in Classification

In the framework of evidence theory, one of the open and crucial issues is how to determine the basic probability assignment (BPA), which is directly related to whether the decision result is correct. This paper proposes a novel method for obtaining BPA based on Adaboost. The method uses training data to generate multiple strong classifiers for each attribute model, which is used to determine the BPA of the singleton proposition since the weights of classification provide necessary information for fundamental hypotheses. The BPA of the composite proposition is quantified by calculating the area ratio of the singleton proposition’s intersection region. The recursive formula of the area ratio of the intersection region is proposed, which is very useful for computer calculation. Finally, BPAs are combined by Dempster’s rule of combination. Using the proposed method to classify the Iris dataset, the experiment concludes that the total recognition rate is 96.53% and the classification accuracy is 90% when the training percentage is 10%. For the other datasets, the experiment results also show that the proposed method is reasonable and effective, and the proposed method performs well in the case of insufficient samples.     

Spectral gap and convergence rate for discrete-time Markov chains

Let P be a transition matrix which is symmetric with respect to a measure π.The spectral gap of P in L2(π)-space,denoted by gap(P),is defined as the distance between 1 and the rest of the spectrum of P.In this paper,we study the relationship between gap(P) and the convergence rate of Pn.When P is transient,the convergence rate of P n is equal to 1 gap(P).When P is ergodic,we give the explicit upper and lower bounds for the convergence rate of Pn in terms of gap(P).These results are extended to L∞(π)-space.