Monte Carlo模拟在聚合反应速率常数估算中的运用

1 Introduction It is i mportant to study polymerization mechanisminpolymerization engineering. Obtaining kinetic data isthe key step for establishing polymerization mechanismand understanding elementary reactions . The kineticdata contains two groups of data ,i.e.,the rate andreaction order .The rate ,especially the rate constant ,is i mportant and to be esti mated assuming that the or-der of the reactionis known.Furthermore ,esti mationof rate constants for polymerization is an active anddif…     

Dynamic Monte Carlo simulation of linear SAW polymer chain near a flat surface

INTRODUCTION The conformational property of polymerchains subject to a geometrical constraint is one of themost interesting topics in polymer science (Milner,1991; Malfreyt and Tildesley, 2000; Vacatello,2001). The geometrical constraint can be a solidsurface, a liquid/liquid interface, a vacuum/liquidinterface, etc. So the topic has many applications intechnology such as adsorption onto interface, sta-bilization of colloids and partition equilibrium ingel permeation chromatography…     

Dynamic Monte Carlo simulation of linear SAW polymer chain near a flat surface

Investigation of the conformational properties of a SAW polymer chain near an impenetrable, non-interacting flat surface showed that the chain at first contracted and orientated itself to slightly parallel when it pulled close to the surface and at last elongated and reoriented itself to slightly perpendicular to the surface at very small distance from the surface. Simulation showed that most of the disappeared configurations were of large size at moderate distance from the surface while they were of small size at very small distance from the surface; and that the mean-square end-to-end distance was much more prone to be influenced by the surface than the mean-square radius of gyration . The orientational correlation between the direction of the longest principal axis of the moment of inertia and end-to-end vector was also discussed.     

用Monte-Carlo方法模拟红巨星轨道根数分布

红巨星是 Ba星的前身星 ,研究红巨星的轨道根数的分布规律对研究双星系统的演化有非常重要的作用。目前 ,在国内外涉及该领域的文章都没有给出红巨星轨道根数的分布规律 ,用 Monte- Carlo方法模拟出普通红巨星的轨道根数的分布规律有重要的意义 ,与观测进行比较 ,结果符合得很好。     

基于集群系统的3D格点Monte Carlo算法并行实现

This paper presents a new approach to parallelize 3D lattice Monte Carlo algorithms used in the numerical simulation of polymer on ZiQiang 2000-a cluster of symmetric multiprocessors(SMPs).The combined load for cell and energy calculations over the time step is balanced together to form a single spatial decomposition.Basic aspects and strategies of running Monte Carlo calculations on parallel computers are studied.Different steps involved in porting the software on a parallel architecture based on ZiQiang 2000 running under Linux and MPI are described briefly.It is found that parallelization becomes more advantageous when either the lattice is very large or the model contains many cells and chains.     

基于蒙特卡罗模拟的不同聚合温度下的丙烯聚合动力学研究

在不考虑其他杂质参与聚合反应的情况下,并基于已有对丙烯聚合反应过程的普适化认识,提出了一个普适的丙烯聚合反应机理(基元反应).在已有的丙烯聚合反应机理基础上,为了证实该聚合反应过程总活性基是否满足“稳态假定”以及考察聚合反应温度对聚合过程的影响,采用蒙特卡罗模拟方法研究了传统Ziegler-Natta催化剂催化下的丙烯聚合动力学.模拟得到的总活性基数目在丙烯聚合初期快速增加到峰值,然后随聚合反应的进行保持恒定,证实了丙烯聚合过程中总活性基符合稳态假定.同时,模拟得到了聚合温度对丙烯聚合过程的转化率、分子量的影响.模拟结果表明:在聚合过程中,丙烯单体的消耗速率随聚合温度升高而增加;不同聚合温度下的数均聚合度峰值相同,但随温度增加,数均聚合度峰值来得早;随聚合温度增加,数均分子量减少,分子量分布变宽.     

用蒙特卡罗法解函数方程

用蒙特卡罗法解一类函数方程,讨论设定概率对平均计算量及方差的影响,给出算例。     

基于Monte Carlo模拟的软土基坑隆起风险评估研究

基于圆弧滑动模型确定的安全系数,将基坑隆起破坏的不利事件划分为5种情况,利用Monte Carlo模拟确定不利事件发生概率,提出了考虑基坑隆起破坏引起的不利事件发生概率及经济损失的风险评估模型。将所提方法应用于福州地铁2号线某基坑工程中,结果表明,当围护结构插入比小于1.2时,加固对基坑隆起破坏损失期望减小效果显著;当围护结构插入比大于1.2时,加固对基坑隆起破坏损失期望减小效果一般;当插入比小于0.8时,基坑隆起破坏的损失期望等级属于“严重”;当插入比介于0.8～1.2时,基坑隆起破坏的损失期望等级属于“需要考虑”;当插入比大于1.2时,基坑隆起破坏的损失期望等级属于“可忽略”。     

Reporting Monte Carlo Studies in Structural Equation Modeling

In structural equation modeling, Monte Carlo simulations have been used increasingly over the last two decades, as an inventory from the journal Structural Equation Modeling illustrates. Reaching out to a broad audience, this article provides guidelines for reporting Monte Carlo studies in that field. The framework of discourse is set by a number of steps to be taken in such research, matching outlines of experimental design by Paxton, Curran, Bollen, Kirby, and Chen (2001) Chen, F., Bollen, K. A., Paxton, P., Curran, P. J. and Kirby, J. 2001. Improper solutions in structural equation modeling: Causes, consequences, and strategies. Sociological Methods & Research, 29: 468–508. [Crossref], [Web of Science ®] , [Google Scholar] and Skrondal (2000) Skrondal, A. 2000. Design and analysis of Monte Carlo experiments: Attacking the conventional wisdom. Multivariate Behavioral Research, 35: 137–167. [Taylor & Francis Online], [Web of Science ®] , [Google Scholar]. Throughout the article, reference is made to exemplary publications and, occasionally, to imperfect reporting.     

用Monte Carlo方法模拟基模Gauss光束

根据基模高斯光场，运用Monte Carlo随机模拟方法，实现了基模高斯光场的模拟，直观地说明了基模高斯光束的横模．     

基于Monte Carlo模拟的宇宙线簇射发展研究

采用CORSIKA中的QGSJET强相互作用模型产生Monte Carlo的EAS事例样本,让所有Monte Carlo事例通过探测器阵列,形成Monte Carlo的观测事例样本。结果证实:通过研究宇宙线高能族事例发展,可以得到较理想的朝前区强子相互作用信息,从而能够有效的对目前正在使用的各种唯象模型的朝前区强子作用性质从TeV能区进行检验。     

Semi-analytical Monte Carlo simulation of laser-induced fluorescence propagation in an optically participating spray

A semi-analytical Monte Carlo (SMC) simulation was developed to simulate the propagation of laser-induced fluo- rescence (LIF) in an optically participating spray, which simultaneously exhibits spectrally dependent emission, anisotropic scattering, absorption, and re-emission. The SMC simulation is described and then applied to an experimental configuration of a cloud of polydisperse droplets composed of water and sulforhodamine B dye. In the SMC simulation, the collected LIF flux on the remote receptor element is calculated as the global contribution from the emissive source, single, twice, … and nth collision events in any sequence. The effects on the fluorescence photons propagation of spray parameters like the dye concentration, droplets concentration, and droplets size are examined. Three spectral bands representing different optical properties are chosen to analyze the interference of absorption, scattering and re-emission on the detected LIF flux. The obtained spectral LIF flux distribution on the receptor demonstrates a “red shift” phenomenon.     

Dynamic Monte Carlo study on the probability distribution functions of tail-like polymer chain

INTRODUCTION Polymer chains with one end attached to a sur- face by means of physical or chemical interaction have become one of the important polymer science subject, which are useful for many applications, such as polymer compatibilizers, copolymer microphases, colloid stabilization, polymeric surfactants (Milner, 1991). Grafting polymers can improve the power efficiency of electrorheological fluids, enhance pho- toluminescence of nano materials, and increase dis- persion stability. On …     

拟蒙特卡罗积分与蒙特卡罗积分

分别介绍了蒙特卡罗方法和拟蒙特卡罗方法的基本思想,从算法本身、误差估计以及收敛率等角度分析了蒙特卡罗方法和拟蒙特卡罗方法的关系,并着重分析其在高维积分中的应用,从而说明拟蒙特卡罗方法的优越性。     

蒙特卡罗数值模拟及其在大跨桥梁可靠度分析中的应用

为了定量地研究大跨桥梁在多种随机因素下的可靠度,采用了蒙特卡罗法中的拉丁超立方体抽样法,对润扬悬索桥(中国跨度最大的悬索桥)在温度、风、车辆荷载、车辆冲击等随机变量作用下的结构可靠度进行了计算.通过对大桥在正常运营和损伤状态下的可靠度分析,获得了大桥主缆应力、吊索应力、桥塔位移以及钢箱梁线形等重要指标的可靠度和累积分布函数,分析结果形象直观,提高了评估的效率,使维护决策的制定更加客观准确.     

带电粒子漂移运动的Monte Carlo模拟

讨论了带电粒子在外电场以及无外电场作用下的漂移运动的物理模型,并且讨论了电流导致导体升温情况下带电粒子的运动,使用Monte Carlo方法对其进行了动画模拟,形象地表现出带电粒子在各种情况下的运动状态．     

理想气体扩散的Monte Carlo模拟

用Monte Carlo方法模拟了理想气体系统通过一小孔的扩散。模拟直观展现了气体分子通过小孔的扩散过程。模拟结果表明,一旦经过扩散达到平衡,系统将不会再回到最初的分布,这说明扩散过程是一个不可逆过程;在扩散过程中,系统的混乱程度不断增大。气体扩散快慢与初始分子数以及小孔的尺寸有关。初始分子数越多小尺寸越大,扩散过程进行的就越快。模拟结果与菲克定律一致。     

Simulation of Bayes' rule by means of Monte Carlo method

This contribution shows a simple implementation of Monte Carlo simulation method when presenting Bayes' rule. The implementation is carried out in the environment of Microsoft Excel spreadsheets by means of a generator of random numbers. The empiric results gained by simulation serve to confirm the correctness of the chosen procedures in calculations using Bayes' formula.     

蒙特卡罗法预测含油气区石油资源量

石油勘探阶段,较准确地估算勘探地区的石油资源量是十分重要的。根据在勘探前所采集到的有限资料,并考虑到蒙特卡罗模拟在分析和求解复杂系统或样本数据少的情况下,更是一种不可缺少的分析技术。本文在随机变量的概率分布,计算局部含油地质单元的石油资源量,计算全局含油地质的石油资源量方面进行了较深入的研究,并通过利用各种数学理论和概率统计方面的知识和数学模型解决问题,按照模型的步骤采用Matlab7．1实现。     

蒙特卡罗方法及其在辐射剂量计算中的应用

概述了蒙特卡罗方法的产生与发展，阐述了蒙特卡罗方法的基本特点，最后就蒙特卡罗方法在辐射剂量计算上的应用进行了讨论。