圆筒空间轴对称稳态热传导解析解

采用坐标变换法导出了圆筒空间轴对称问题稳态热传导温度分布的关系式 .由圆筒内外侧冷热流体介质沿轴向的温度分布计算圆壁内各处温度分布 .计算结果与实验结果吻合很好 .所得公式的适用条件与多数实际情况一致 ,可用于实际热传导工程计算 .此方法计算工作量小 ,结果准确     

奇偶函数在对称区域上的曲线积分公式及其证明

探讨了奇偶函数在对称区域上的第一类曲线积分公式和第二类曲线积分公式,并给出了积分公式的证明,以简化某些积分的运算.     

二次效用极大的证券组合优化模型及算法

本文建立了二次效用极大的证券组合优化模型，研究了各种优化模型的算法，得到了最好证券组合的期望收益率，风险，期望效用及投资比例计算公式。     

工件以圆孔定位时定位误差计算的理论问题

针对几所重点大学所编《机床夹具设计》教材中有关工件以圆孔定位时定位误差的计算公式的错误,论文推导出了正确的计算公式。     

弱酸溶液酸度的计算

文中通过实例讨论了计算弱酸溶液酸度近似公式和最简公式的适用范围,导出了精确计算弱酸溶液酸度的三次方程,并用浓度-pH图讨论了三个公式的使用规则。     

双层钢板混凝土组合剪力墙的抗剪性能(英文)

为深入了解双层钢板混凝土组合剪力墙的抗剪性能,采用数值模拟的方法研究了钢板厚度、混凝土厚度、混凝土强度及组合剪力墙的跨高比等主要参数对该组合剪力墙抗剪性能的影响规律,并提出了该组合剪力墙弹性抗侧刚度及抗剪极限承载力的简化计算公式.研究表明:随着钢板厚度、混凝土厚度、混凝土强度等级的增加,组合剪力墙的抗剪性能均有较显著的提高;组合剪力墙跨高比的变化对其弹性抗侧刚度影响较大,而对其抗剪极限承载力的影响并不明显.通过将公式计算结果与有限元计算结果进行对比分析,发现提出的简化计算公式较合理,能较好地反映双层钢板混凝土组合剪力墙的实际受力状态.该结论可作为双层钢板混凝土组合剪力墙初步设计的参考建议.     

几类积图的平均距离计算公式

本文给出了由路和圈以及完全图构成的积图的平均距离的计算公式或计算方法,推广了现有的一些计算结果。     

信号交叉口行人相位配时方法

以信号交叉口行人相位配时为研究对象,针对信号交叉口行人和机动车对配时要求不一致以及我国行人相位清空时间不足的问题,借鉴HCM中行人绿灯最小时间和行人闪时间的计算公式,利用交通流理论,分析了行人相位和机动车相位关系,并建立了不同情况下行人信号配时方法,尤其是行人绿灯时间的调整方法.讨论了不同中央分隔带形式和宽度的行人过街方式,对计算参数的取值进行了研究,在此基础上,给出了不同情况下建议的行人配时计算模型.     

Theoretical Calculation and Analysis of Slip and Deformation for Concrete Sandwich Panels

Slip and deformation of concrete sandwich panels under uniformly distributed loads is concerned. The effect of slip on the deformation of concrete sandwich panels are studied,and the analytical expressions of slip and deformation for concrete sandwich panels is obtained. These formulae can describe the slip distribution and account for its effect on deformation. In order to restrict the bound of formula, the formula of crack moment is obtained. The results of theoretical calculation are compared with those of tests and finite element methods. The comparison shows that the results of theoretical calculation are in accord with those of tests and finite element methods. So the theoretical calculation can be used to calculate slip and deformation of concrete sandwich panels in practical projects.     

关于《燃烧热的测定》实验中热平衡计算式的商榷

本文证明用外壳等温式弹式量热计测定物质燃烧热时，在许多教材中长期使用的基本公式中存在错误，并对正确计算公式提出了见解．     

Experimental Study of Structure Shock Vibration in Soft Caused by Explosion of Conventional Weapons

When hitting underground structures directly or exploding in rock-soil media near underground structures, the conventional weapons with large charge weight will make underground structures be subjected to strong shock vibration and cause personal casualty and damage of precision electronic equipments, The shock vibration has become one of the cardinal killing means of weapons. However, the existing methods of predicting structure shock vibration are limited evidently. In this paper the coupling coefficient of acceleration in clayey soil is obtained firstly. Subsequently based on repeated experiments of chemical explosion, after dimension analysis and by using method of multivariate stepwise regression, the calculation formulae of shock vibration acceleration for the underground structure are obtained finally. The formulae consider top and side explosion respectively, taking into account the effects of penetration depth, charge weight, distance to explosion center, rock-soil media, size of structure and buried depth. They are easy to use with high practicability and degree of confidence, and can provide credible evidence for prediction of shock vibration and vibration isolating design of underground structure.     

FAILURE SURFACE AND CAPACITY OF REINFORCED CONCRETE MEMBERS SUBJECTED TO BIAXIAL TENSION

A computer program is developed for the nonlincar analysis of prestressedconcrete and nonprestressed concrete members subjected to combined biaxial bending andaxial load.The strength-interaction diagrams and failure surface are obtained.Thestrength design formulae are proposed.     

集体建设用地流转价格扭曲原因及其鉴定方法

随着我国城市化进程的加快和乡镇经济的蓬勃发展,集体建设用地的流转规模不断扩大,但其流转价格也普遍出现了扭曲现象,不利于资源配置的最优化。文章主要运用经济学相关理论对集体建设用地流转价格扭曲的原因进行了综合分析,并结合我国土地市场的现实状况讨论了相应的流转价格鉴定方法——收益还原法、成本法、市场比较法,详述了这些方法的计算公式,运行步骤及其需注意的相关问题。     

单摆运动周期几个近似公式的比较

采用数值计算方法,利用Mathematica软件求出了在忽略空气阻力情况下单摆运动周期的精确解。在此基础上,利用MATLAB曲线拟合的方法,绘制出精确解的函数曲线,进而对多种文献给出的单摆周期近似计算公式进行了比较。     

机械优化设计中的模糊性分析

分析了机械优化设计中忽略机械零部件模糊因素的缺限,给出了机械优化设计考虑模糊性的模型描述及计算方法,详细地介绍了模糊优化的隶属函数的建立方法以及如何采用最优水平截集对其进行优化,并通过实例计算的两种设计结果的比较,说明模糊优化设计更符合客观实际。     

Experimental Study of Structure Shock Vibration in Soil Caused by Explosion of Conventional Weapons

When hitting underground structures directly or exploding in rock-soil media near underground structures, the conventional weapons with large charge weight will make underground structures be subjected to strong shock vibration and cause personal casualty and damage of precision electronic equipments. The shock vibration has become one of the cardinal killing means of weapons. However, the existing methods of predicting structure shock vibration are limited evidently. In this paper the coupling coefficient of acceleration in clayey soil is obtained firstly. Subsequently based on repeated experiments of chemical explosion, after dimension analysis and by using method of multivariate stepwise regression, the calculation formulae of shock vibration acceleration for the underground structure are obtained finally. The formulae consider top and side explosion respectively, taking into account the effects of penetration depth, charge weight, distance to explosion center, rock-soil media, size of structure and buried depth. They are easy to use with high practicability and degree of confidence, and can provide credible evidence for prediction of shock vibration and vibration isolating design of underground structure.     

Why and how people of limited intelligence become calendrical calculators

Abstract

Calendrical calculation is the rare talent of naming the days of the week for dates in the past and future. Calendrical savants are people with low measured intelligence who have this talent. This paper reviews evidence and speculation about why people become calendrical savants and how they answer date questions. Most savants are known to have intensively studied the calendar and show superior memory for calendrical information. As a result they may answer date questions either from recalling calendars or by using strategies that exploit calendrical regularities. While people of average or superior intelligence may become calendrical calculators through internalizing formulae, the arithmetical demands of the formulae make them unlikely as bases for the talents of calendrical savants. We attempt to identify the methods used by a sample of 10 savants. None rely on an internalised formula. Some use strategies based on calendrical regularities probably in conjunction with memory for a range of years. For the rest a decision between use of regularities and recall of calendars cannot be made.     

素数的算法

通过对模为2的余新河问题的研究，给出了所有专素数的一个算法公式．     

神经网络在系统优化设计中的应用

本文首先简介了系统优化问题，然后以Hopfield神经网络在对铺设公路至若干油田的路线进行优化设计中的应用为典型事例，初步探讨了在复杂系统的优化方案设计中运用人工神经网络的可行性，并从中得出拥有并行分布计算优势的神经网络在解决系统组合优化问题时具有优越性这一结论。     

完全混合流反应器优化组合的探讨

该文对多个完全混合流釜式反应器的优化组合进行了探讨,得出了使总容积为最小的各反应器出口转化率计算的递推公式,为反应器组合的研究和工业装置的优化排列提供了参考。