NOTE ON THE SOLUTION OF THE EQUATIONS CONTROLLING STABILITY OF NONLINEAR THERMOELASTIC WAVES IN A SPINNING DISK

A general solution to the system of coupled differential equations with periodic coefficients, established in [1] and determining the stability of a spinning heated disk, is given.     

农村供水管网延伸设计与ExceI计算的应用

在农村饮水管网延伸工程中，采取因地制宜的设计方案，可以充分发挥现有供水工程潜力。在满足现行标准和用户要求的前提下，兼顾方案的经济合理，使工程充分发挥效益，是工程设计人员应当研究的问题。该文主要介绍供水管网延伸方案设计的设计依据、基本内容和计算方法，以供类似工程借鉴。     

大化水电站扩建工程刺墙坝设计

大化水电站扩建工程的接头土石坝中间设置刺墙坝,使得坝顶能够提前贯通,机组设备大件能够提前运输至厂房进行安装,缩短了发电工期,同时采用简洁的体型,减少刺墙坝对土石坝的施工干扰,并进行了基础处理。经过两年多时间的运行,证明刺墙坝设计合理、安全稳定,满足使用功能。     

一种针对位操作密集应用的扩展指令自动选择方法

本文提出一种结合位操作分析和变换的扩展指令自动选择方法。该方法在数据流图中引入新的位操作中间表示结点，可精简地描述位访问操作。编译器可对程序数据流图进行选择性循环展开和位操作分析优化，并将其转换为带有直接表示位赋值操作结点的数据流图。实验结果表明，基于新的数据流图进行扩展指令选择可有效提升位操作密集型应用的性能     

沪宁高速公路扩建工程交通组织方案特点介绍

结合沪宁高速公路扩建工程交通组织的设计及施工情况,介绍了高速公路扩建工程交通组织方面的特点,从而大大降低了泸宁高速公路扩建工程交通组织的投资成本,为今后高速公路扩建工程的交通组织提供了参考。     

Study of the simple extension tear test sample for rubber with Configurational Mechanics

The simple extension tear test-piece also referred to as the trousers sample is widely used to study crack propagation in rubber. The corresponding energy release rate, called tearing energy for rubber materials, was first established by Rivlin and Thomas (J Polym Sci, 10:291–318, 1953); a second derivation was proposed later by Eshelby (In G.C. Sih, H. C. van Elst, and D. Broek, editors, Prospects of Fracture Mechanics, 69-84, Leyden, 1975). We show here that the derivation of this result can be advantageously revisited through the scope of Configurational Mechanics. Our approach is based on the rigorous definition of the configurations of the body and on the physical significance of the configurational stress tensor. More precisely, it is demonstrated that the change in energy due to crack growth, and then the tearing energy, is directly related to the components of the configurational stress tensor in the body.     

添加剂对面团纵横向拉伸应力影响的研究

初步研究了氯化钠、碱、磷酸盐、瓜儿胶、谷朊粉和乳化剂等各种添加剂在压延时对面团纵横向拉伸特性的影响。结果表明,不同添加剂对面团纵横向拉伸特性的影响不同,同时还从侧面证明了压延的方向性对面带中面筋网络形成有影响。     

Synthesis and characterization of poly(lactic acid) and aliphatic polycarbonate copolymers

BACKGROUND: Poly(lactic acid) (PLA) has received much attention as a biodegradable polymer. But the physical properties of PLA, such as brittleness, limit its wider applicability. Copolymerization polymers ing soft blocks provides a useful method to improve the mechanical properties of PLA. RESULTS: Poly(lactic acid)‐block‐(polycarbonate diol) (PLA‐PCD) copolymers were synthesized using a two‐step process with polycondensation and chain extension reactions. The effect of polycarbonate diol content on the prepolymer properties was studied. The chain‐extended products were characterized using ¹H NMR, F and. The effect of the NCO/OH ratio on the properties of the chain‐extended products, including the mechanical properties and thermal properties, was studied. eight‐average molecular weight of the product can reach 210 000 g mol^?1 when the molar ratio of ? NCO to ? OH is 3:1. CONCLUSION: The PLA‐PCD copolymers obtained can crystallize, and the crystallinity decreases with chain‐extension reaction. The products exhibit superior mechanical properties with elongation at break above 230%, which is much higher than that of PLA chain‐extended products. The products have a good potential for packaging applications. Copyright © 2009 Society of Chemical Industry     

Weibull extension model: A Bayes study using Markov chain Monte Carlo simulation

Several generalizations of the two-parameter Weibull model have been proposed to model data sets that exhibit complex non-monotone shapes of hazard rate function. The present paper focuses on one such generalization referred to as the Weibull extension model in the literature. Complete Bayesian analysis of the model has been provided using Markov chain Monte Carlo simulation. Finally, a thorough study has been conducted for checking the adequacy of the model for a given data set using some of the graphical and numerical methods based on predictive simulation ideas. A real data set is considered for illustration.     

曲流河层内夹层分布对水驱开发效果的影响

根据喇萨杏油田曲流河层内夹层分布特征及喇萨杏油田PⅠ组油层参数,建立了夹层数值模拟模型。研究了夹层倾角、水平间距、纵向延伸长度/油层厚度(H夹层/H油层)等因素对水驱采收率和含水率的影响。结果表明,夹层倾角、间距及H夹层/H油层对水驱采收率均有影响,且幅度较大;随倾角(3～15°)增大水驱采收率增加,但7～15°增幅较缓;夹层间距(10～40m)增大,水驱采收率近似呈线性增加;H夹层/H油层(0～2/3)增加,水驱采收率降低;随夹层倾角和水平间距增大,含水率下降;H夹层/H油层对含水率影响较大,相同采收率下,随H夹层/H油层增加,含水率明显增加。得出了夹层分布对水驱开发效果有重要影响的结论,提出了今后进行油藏精细描述和层内剩余油挖潜应重视夹层分布影响的建议。