三交和双交组合加性-显性-母体效应的遗传模型及蒙特卡罗模拟分析

本文根据广义遗传模型的建模原理,按照三交和双文组合方式的交配设计,分别提出了分析 作物三交和双交组合数量性状的加性－显性－母体效应的遗传模型（ＡＤＭ模型）,给出了不同环境下各 世代群体的遗传效应分量。应用ＭＩＮＱＵＥ（１）法对包括不同世代的三交和双交组合的ＡＤＭ模型进行 了蒙特卡罗模拟分析,结果表明：采用亲本和三（双）交Ｆ_１两个世代分析三（双）交组合的ＡＤＭ模型 时,即可获得方差分量的无偏估计值和遗传效应的无偏预测值;采用包括单交Ｆ_１在内的三个世代联合 分析时,更有利于提高显性等遗传效应方差分量的估算效益。最后讨论了利用单交组合预测三交和双 交组合遗传表现的有关问题。     

三交和双交组合加性-显性-母体效应的遗传模型及蒙特卡罗模拟分析

本文根据广义遗传模型的建模原理, 按照三交和双交组合方式的交配设计, 分别提出了分析作物三交和双交组合数量性状的加性-显性-母体效应的遗传模型(ADM模型), 给出了不同环境下各世代群体的遗传效应分量。 应用MINQUE(1)法对包括不同世代的三交和双交组合的ADM模型进行了蒙特卡罗模拟分析, 结果表明： 采用亲本和三(双)     

基于蒙特卡罗的水产品中甲醛定量风险评估

通过开展水产品中的甲醛定量风险评估工作,量化中国普通居民食用水产品途径的甲醛膳食风险水平。运用基于蒙特卡罗模拟的@risk软件,以风险商表征食用水产品途径的甲醛膳食风险。评估结果表明,中国普通居民通过食用鲜活水产品及干制水产品途径摄入甲醛的风险商平均值和各百分位数风险商均小于1,且通过食用干制水产品途径的甲醛膳食风险商平均值和各百分位数均比食用鲜活水产品途径的甲醛膳食风险商平均值和各百分位数要低1个数量级。因而,中国普通居民仅通过食用水产品途径的甲醛膳食暴露尚不存在健康风险,但是仍需加强对鲜活水产品中甲醛的控制和监测,从而进一步降低中国普通居民食用水产品途径的甲醛膳食风险水平。     

A New Monte Carlo Method Based on State Analysis

A new Monte Carlo Method for system reliability evaluation is proposed in this paper. The repeated sampling of system states with relatively great probabilities is avoided in the simulation,thus the sampling efficiency is significantly improved. Besides,the negative correlations used in different trials can further reduce the estimated varinaces. The sparse matrix technique is employed to reduce the memory requirement and to save the computer time. Comparative studies show that the method proposed is of great value and the application to the IEEE reliability test system (power system) is successful.     

Option Pricing Using Quasi-Monte Carlo Simulation

This paper firstly introduces the method of option pricing using Monte Carlo,then,proposes one kind of Quasi-Monte Carlo Simulation,which uses Halton sequences to improve Monte Carlo Simulation.This paper also introduces generated rule of Halton Low Discrepancy Sequences and Moro algorithm.Finally,the performances of three kinds of Quasi-Monte Carlo method are compared.     

Sensitivity analysis of a motorcycle frame using the Monte Carlo method

Sensitivity analysis of motorcycle frames is useful for improving the design success rate. Based on sensitivity analysis theory and using the Monte Carlo and numerical simulation methods, a new 250 type integral motorcycle model was built and dynamic sensitivity analysis conducted. Sensitive design parameters that have great influence on frame vibration were discovered. By modifying the values of sensitive design parameters, the vibration of some measuring points was reduced. This reduction shows that the sensitivity analysis method is reliable and practical, and it can be used in sensitivity analyses of other complicated structures.     

A Fractal Model of the Microstructure

In this paper,a fractal model about the microstructure of spheroidal-graphite is presented through the research on the surface form and the analysis to microregion. The fractal dimension is calculated and the forming mechanism is also discussed.     

Application of Monte Carlo Method to the Light Scattering of Human''s Erythrocytes

The forward small-angle light scattering of the human's static and deformed erythrocytes in Couette flow is simulated by Monte Carlo method. It considers the light traveling along the cells in thin suspension, the values of length in all three axes and the deformation degree are worked out by anomalous diffraction. The result shows that the feasibility of this method is supported by its closeness to the standard data of model.     

蒙特卡洛模拟在种质资源研究中的应用探讨

种质资源是育种工作的前提,然而种质资源研究极耗时间和资金.蒙特卡洛模拟是利用计算机虚拟试验解决现实问题的强大工具.利用蒙特卡洛模拟进行种质资源研究,可以节省大量人力物力,并且能够完成现实中无法进行的试验.本文介绍了蒙特卡洛模拟方法的原理,综述了蒙特卡洛模拟在种质资源研究中的主要应用.并且提出了应用蒙特卡洛模拟构建种质资源群体的两种策略.     

COTGROW：棉花生长发育模拟模型

ＣＯＴＧＲＯＷ模型是应用作物模型的理论和方法，借鉴国外同类模型的经验，在多年田间试验研究的基础上，根据中国棉花生产管理的实际，研制完成的一个融棉花生长发育与产量形成及常规栽培管理为一体的动态模拟模型。该模型的核心部分由碳素平衡、发育与形态发生、水分平衡、氨六平衡、栽培措施和输入与输出等模块构成，可根据土壤和气候数据模拟播种期、密度、地膜覆盖、去早蕾、打顶、喷缩节安、喷乙烯利、灌溉和施肥等单个或组合措施条件下的棉花生长发育、产量和品质形成，还可模拟２ｍ上层内各上层的土壤水分状况、氮素状况及植株各部分的含氮量和最终棉株对氮、磷、钾的吸收量。利用模型模拟不同栽培措施对棉花产量的影响结果表明，各种措施的产量拟合指数都在０．８５以上；模拟安阳１９８５年至１９９４年不同气候条件下的产量也具有很好的一致性。但模型还需要在其他类型气候和土壤条件下进行检验。     

Model Building and Simulation for Subcritical Pressure Boiler

In order to meet the demand of large scale boiler design and operating optimization, this paper establishes the dynamic mathematic model for domestic 600MW subcritical pressure boiler. MMS software is adopted in the whole process from modeling to simulation. This software make process simple and quick. This model is based on modulariza- tion and the comprehensive physical and chemical process in boiler is considered. Simulation result shows that the re- sponses of this model under different disturbance are coincident to mechanics analysis. The simulation result under ste Pdisturbance can be used to analyze unit changes and provide some guide and it also can supply performance reference data to boiler design.     

棉籽蛋白质和油分形成的模拟模型

基于不同熟性棉花品种的异地分期播种和施氮量试验,综合量化品种特性、主要气象条件(温度、太阳辐射)和栽培措施(施氮量)对棉籽蛋白质和油分的影响,基于棉籽氮素积累和油分合成的“库限制”假设,结合棉花铃期与棉籽干物质积累模型,建立基于过程的棉籽蛋白质和油分形成模拟模型。利用不同生态点不同品种、播期和施氮量的田间试验资料对模型进行检验的结果表明,供试品种科棉1号和美棉33B棉籽的蛋白质含量模拟值与实测值的根均方差(RMSE)分别为2.05%和2.33%,其油分含量模拟值与实测值的RMSE分别为2.45%和2.95%。模型以主要气象资料(日平均温度、日太阳辐射量)和栽培措施(施氮量)作为模型输入,以棉花铃期与棉籽干物质积累模拟模型为基础,实现了较广泛生态条件下对不同品种棉花棉籽蛋白质和油分形成过程的模拟及其含量的动态预测。模型预测精度高,广适性强。     

A Delay Model and Simulation Studies for None-Signaller Intersections

A model based on Queueing Theory was developed for calculating the average queueing delays and the capacities of intersections. And the turning flows influences on the delay were analysed,the simulation results were presented in the article.     

棉花形态发生和叶面积指数的模拟模型

棉花形态发生的模拟以每日生理热效应为主要驱动因子,同时考虑了地膜覆盖后地温升高对气积温的补偿作用。叶面积指数的模拟基于棉花LAI动态消长与物质流的库源关系,量化了棉花生育过程中源或库不足时的LAI增长过程。通过对模型参数的校正和核实,使模型适应于不同类型品种的形态发生和LAI动态模拟。结果表明,叶片数、株高、果枝和果节的模拟精度均差方根(RMSE)分别达到了0.7片、1.6cm、0.8个和3.3个;叶面积指数在不同品种和管理方式下的模拟精度RMSE达到了0.3,表现出较好的吻合度和适用性。     

大豆阶段发育动态模型的研究与建立

研究了不同大豆类型品种的发育与温、光等主要环境因子的数量关系,在借鉴吸收析因指数形式的小麦发育期动态模拟模型（WDSM）、“水稻钟“模型和DSSAT3等模型思想方法基础上,构建了大豆阶段发育动态模拟模型（SDSM）。经验正不同类型品种平均误差在1~2d内,与传统的积温法相比,其模拟精度有了较大提高。     

Lightning Shielding Simulation Model of Transmission Line

Transmission lines are easily hit by lightning, and lightning shielding failure is an important reason of lightning accidents of transmission line. So researches on lightning shielding of transmission line should be strengthened. On the basis of the abundant understand to known lightning shielding models of transmission line, a new lightning shielding simulation model of transmission line is presented in the paper. In this model, the effect of attracting lightning of upward leader is considered reasonably, and the method of variable descending step is adopted to simulate the descending process of lightning leader. The simulation calculating results show that the model is in good agreement with field experience of transmission line. It can guide lightning shielding design of transmission line and estimate the performance of lightning shielding of transmission line.     

作物模拟研究中的模型检验

分析了作物模拟研究中模型检验的常用统计判据相关系数、标准差与变异系数在统计学意义上的原理和不足，提出了模拟值的置信度和置信带的概念。以玉米发育期模型为例，分别用相关系数和置信度对模拟值和实测值进行检验。     

水稻生长模型研究进展

简单介绍了作物生长模型发展历史,重点介绍了水稻生长模拟模型的发展历史,阐述了当前水稻生长模型的应用情况。水稻生长模型基于水稻的生长机理,在未来气候情景模拟、区域化模拟、优化栽培及气象灾害影响评估中的应用已取得了较好成果。随着时代的进步,对模型模拟研究提出了新的需求。针对模拟模型当前的应用情况,提出了未来发展的几点建议对策,以期为作物生长模型在今后的农业生产实践中起到指导作用。     

棉花株高动态模拟与预测方法初探

【研究目的】为棉花高产栽培提供科学、实用的株高动态模拟模型、诊断指标和预测方法。【方法】分别采用传统的日期-株高法和创新的叶龄-株高法、叶龄-相对株高法对两年6点棉花超高产试验中的株高资料进行统计分析。【结果】与传统方法相比,叶龄-相对株高法模拟精度高,适用范围广;用此法所制定的株高诊断指标,有广泛的适用性和灵活性;根据该方法提出的株高预测方法,简便、实用、可靠。【结论】叶龄-相对株高法不仅适用于对棉花株高的模拟、预测和诊断指标的制定,也可在其它作物上试用。