引力子三点与四点Green函数对量子Wilson圈的贡献

基于微扰法 ,计算了引力子三点、四点Green函数对Einstein引力的量子Wilson圈的贡献 .结果表明 ,在κ4 阶Einstein引力又获得了定域曲率的激发     

海东地区森林资源管护工作现状及对策

经对海东地区森林资源管护工作的调查,针对存在的问题和现状.提出搞好森林资源管护工作的对策.     

一种新非简谐振子势的阶梯算符

本文运用超对称构造出了一种新精确可解非简谐振子势的能量阶梯算符，并由阶梯算符求出了其能量本征值和本征函数。     

Evaluation of genetic diversity and relationships within and between two breeds of duck based on microsatellite markers

The genetic diversity of two natural populations (M, N) of Beijing duck (Anas platyrhynchos) and 11 artificially selected lines of Beijing duck (A, B, E-L, O) from China Gold Star Duck Production Ltd., along with two Cherry Valley duck lines (C and D) from the British Cherry Valley Livestock Division, was evaluated using 18 microsatellite markers covering 16 linkage groups. A phylogenetic tree of the 15 populations of duck, formed of four main branches, was constructed from Nei’s D_A genetic distance. The mean genetic differentiation index (F_ST) in all loci, Nei’s standard genetic distance (Ds), and the genetic distance D_A between the Beijing duck and the Cherry Valley duck were 0.075, 0.143 and 0.142, respectively. These results demonstrated a high degree of genetic similarity between the two breeds and supported the hypothesis that the Cherry Valley duck was derived from the Beijing duck. The F_ST matrix of seven clusters of Beijing duck suggested that the efficiency of selection was not significant to some extent and should be supplemented by marker-assisted selection.     

A Sensitivity-Based Heuristic Search for Constrained Optimization in Complex Systems

1.INTRODUCTIONThealgorithmforconstrainedoptimizationincomplexsystemscanbedividedintotwoclasses:exactandheuristicmethods.Theexactmethods,whicharepartlysummarizedbyTitanetal.[1],havecomputationalrequiremeatsthatgrowexponentiajlywiththesizeoftheproblem.AlthoughheuristicmethodshavemodestcomputationalrequirementsandareeasytoAnplemellt,theyaregenerallyforredundancyallocation[2-4].2.S~EMENTOFProBLEM2.1NotationN:nUmberofcomponents;M:numberofconstraints;Rs:systemreliability;Rj:thereliabili…     

薏苡仁酯对荷瘤小鼠红细胞免疫功能及Na~+,K~+-ATPase活性的影响

薏苡仁酯对荷瘤小鼠红细胞免疫功能具有显著的促进作用，对红细胞膜上的Ｎａ＋，Ｋ＋－ＡＴＰａｓｅ有抑制作用。其抑制作用呈量效正相关。薏苡仁酯的后一作用可能是其促进荷瘤小鼠红细胞免疫功能的机理之一。     

大规模开发活动中的城市规划设计思想与实践

我国城市发展与更新的主要动力已由单一的政府投资趋向投资主体的多元化，因此综合考虑政府和开发企业的目标及公众利益已十分必要。从国内的经验看，规划的成败在于规划与投资行为以及市场需求的结合上，规划者需要掌握如何从公众的角度出发，维护公共利益。另一方面也要了解市场经济的原则，了解各开发主体运作状况和需要，使规划和设计具有实际可实施性。文中通过对当今西方国家以促进经济发展为主题的城市规划理论和实践的回顾，     

浅谈图解法的计算机化

本文介绍用计算机求解画法几何中直线与直线、直线与平面及平面与平面的相对位置问题的方法和程序设计。     

高速小型汽油机的准维燃烧模型

建立了用于二冲程汽油机的准维湍流火焰传播模型，计算结果与试验相符合，表明准维湍流火焰传播模型对于高速二冲程汽油机具有良好的适用性．     

在极低温下照射种子的生物学效应 Ⅲ·液氮低温的刺激增产和诱变作用

基于极低温对种子γ辐射效应的影响,研究了液氮低温(-196℃)单因子的生物学效.发现液氮处理冬小麦风干种子,不仅有损伤效应,也有刺激增产和诱变作用.实验结果表明:在液氮中进行种子γ照射应考虑这些因素,并对发展中的低温生物学也提出了有待研究的新问题.