核子白旋结构的实验研究进展

本文主要介绍对核子纵向自旋结构函数的实验研究进展。首先简要介绍核子自旋结构的部分理论模型,包括朴素的部份子模型和QCD中的夸克一部份子模型,同时简要介绍标度律和标度律的破坏及其原因;接着介绍实验研究的理论基础,包括弱作用和轻子一核子的深度非弹散射中轴流的作用和几个关于核子自旋结构的求和规则和它们的QCD修正;且简要介绍深度非弹散射实验的研究方法,包括单举测量、半单举和遍举测量。最后,详细介绍实验研究进展,包括对质子和。中子的纵向自旋结构函数的测量,国际上几个主要实验室在不同的能量下,在用不同的靶、不同的束流对不同范围的Bjorken变量x和不同的四动量转移范围Q2下的实验、特点及其结果。最后简略介绍了我国实验物理工作者在该领域的国际合作组的部分工作。     

基于跟车行为的双车道交通流元胞自动机模型：

结合跟车行为中车辆相对运动的影响和安全驾驶条件,引入换道规则,提出了基于跟车行为的双车道元胞自动机模型．模型可以描述系统在临界密度附近的亚稳态性质,其仿真结果与实测数据符合很好．在对车辆换道仿真数据采集处理的基础上,研究满足换道条件的车辆数和车辆密度间的关系,定义了换道函数描述标准驾驶行为下的车辆换道过程,求得函数的解析解并使用函数预测经换道达到稳定的车辆密度值,为量化和深入研究车辆的换道行为提供参考．     

Conductivity exponent in three-dimensional percolation by diffusion based on molecular trajectory algorithm and blind-ant rules

Diffusion on random systems above and at their percolation threshold in three dimensions is carried out by a molecular trajectory method and a simple lattice random walk method, respectively. The classical regimes of diffusion on percolation near the threshold are observed in our simulations by both methods. Our Monte Carlo simulations by the simple lattice random walk method give the conductivity exponent μ/ν=2.32±0.02 for diffusion on the incipient infinite clusters and μ/ν=2.21±0.03 for diffusion on a percolating lattice above the threshold. However, while diffusion is performed by the molecular trajectory algorithm either on the incipient infinite clusters or on a percolating lattice above the threshold, the result is found to be μ/ν=2.26±0.02. In addition, it takes less time step for diffusion based on the molecular trajectory algorithm to reach the asymptotic limit comparing with the simple lattice random walk.     

Thresholding methods to estimate copula density

This paper deals with the problem of multivariate copula density estimation. Using wavelet methods we provide two shrinkage procedures based on thresholding rules for which knowledge of the regularity of the copula density to be estimated is not necessary. These methods, said to be adaptive, have proved to be very effective when adopting the minimax and the maxiset approaches. Moreover we show that these procedures can be discriminated in the maxiset sense. We provide an estimation algorithm and evaluate its properties using simulation. Finally, we propose a real life application for financial data.     

Lagrangian domain reductions for the single machine earliness–tardiness problem with release dates

This paper presents new elimination rules for the single machine problem with general earliness and tardiness penalties subject to release dates. These rules, based on a Lagrangian decomposition, allow to drastically reduce the execution windows of the jobs. We measure the efficiency of these properties by integrating them in a branch-and-bound. Tests show that instances with up to 70 jobs without release dates, and up to 40 jobs with release dates, can be optimally solved within 1000 seconds.     

Decomposition Method with a Variable Parameter for a Class of Monotone Variational Inequality Problems

In this paper, we focus on a useful modification of the decomposition method by He et al. (Ref. 1). Experience on applications has shown that the number of iterations of the original method depends significantly on the penalty parameter. The main contribution of our method is that we allow the penalty parameter to vary automatically according to some self-adaptive rules. As our numerical simulations indicate, the modified method is more flexible and efficient in practice. A detailed convergence analysis of our method is also included.     

Simple ingredients leading to very efficient heuristics for the maximum clique problem

Starting from an algorithm recently proposed by Pullan and Hoos, we formulate and analyze iterated local search algorithms for the maximum clique problem. The basic components of such algorithms are a fast neighbourhood search (not based on node evaluation but on completely random selection) and simple, yet very effective, diversification techniques and restart rules. A detailed computational study is performed in order to identify strengths and weaknesses of the proposed algorithms and the role of the different components on several classes of instances. The tested algorithms are very fast and reliable: most of the DIMACS benchmark instances are solved within very short CPU times. For one of the hardest tests, a new putative optimum was discovered by one of our algorithms. Very good performances were also shown on recently proposed and more difficult instances. It is important to remark that the heuristics tested in this paper are basically parameter free (the appropriate value for the unique parameter is easily identified and was, in fact, the same value for all problem instances used in this paper).     

Sequential stopping rules for the multistart algorithm in global optimisation

In this paper a sequential stopping rule is developed for the Multistart algorithm. A statistical model for the values of the observed local maxima of an objective function is introduced in the framework of Bayesian non-parametric statistics. A suitablea-priori distribution is proposed which is general enough and which leads to computationally manageable expressions for thea-posteriori distribution. Sequential stopping rules of thek-step look-ahead kind are then explicitly derived, and their numerical effectiveness compared.     

取代吡啶衍生物的13C NMR谱研究

本文测试了三十三个α、β、γ单取代吡啶和二、三取代吡啶衍生物的¹³C NMR谱,归属了全部¹³C NMR谱线。由其¹³C NMR谱线变化规律,研究和总结出各类碳数大于2的烷基取代基对α、β、γ单取代吡啶环碳化学位移的经验取代参数和吡啶环作为一个官能团对烷烃衍生物的取代效应,讨论了单烷基和多烷基吡啶的取代基加和规律。