高层级轮胎各层帘布裁断角度的计算方法

提出一种新的确定高层级轮胎内外各层帘布裁断角度的方法。根据各层帘布在成品胎内部的材料分布图和在成型机头上的材料分布图，计算该层所在的机头宽度，比较计算的机头宽度和实际的机头宽度，通过调整帘布裁断角度使两者近似相等。以此确定各层帘布的裁断角度，达到内外层帘线均匀伸张的目的。     

7.50-16 12PR轻型载重轮胎的优化设计

介绍轻型载重轮胎的优化设计。采取的主要措施是：减小轮胎外缘尺寸，外直径由８０８ｍｍ减至７９８ｍｍ，断面宽由１９８ｍｍ减至１９５ｍｍ；胎面花纹以纵向花纹为主，肩部为纵横结合花纹并加深肩部通挖花纹沟的深度，改善肩部生热；胎体帘布采用加粗减层的方法，用６层１８７０ｄｔｅｘ／２尼龙帘布代替８层１４００ｄｔｅｘ／２帘布。优化轮胎重量减轻４ｋｇ，轮胎性能符合国家标准。     

微机用于抛物线齿同步带传动强度理论的研究

采用啮合原理与弹性力学复交函数相结合的方法，借助计算机对抛物线齿同步带传动强度理论进行了系统研究，并将整个计算过程编制成ＲＨＤＧＲＡＰＨ软件。利用该软件进行了带齿和轮齿及刀具齿形设计、啮合原理分析、应力和变形计算、刀具可加工最小齿数的确定及加工误差分布计算。     

Crystallization Behaviors of amino-terminated polyurethane (ATPU)-grafted polypropylene

Summary A melt-grafting approach was employed to prepare a novel functional polypropylene(FPP)—amino-terminated polyurethane grafted polypropylene (PP-g-ATPU). The crystallization behaviors of PP and PP/FPP blends were characterized using differential scanning calorimetry (DSC), wide angle X-ray scattering (WAXS) and polarized optical microscopy (POM). The effects of FPP composition on crystallization behavior, crystal transformation, and morphology of PP/FPP crystalline were investigated. The results showed that at a low dosage (<2.0 wt%) ATPU acted as a heterogeneous nucleation agent during the crystallization of PP/FPP blends. However, when the content of ATPU reached 2.0 wt% or higher, ATPU deteriorated the crystallization of PP or PP/FPP blends. The crystallite size decreased and the number of crystallites increased as the ATPU content increased. The Avrami analysis was adopted to describe the isothermal crystallization process. The difference in the exponent n between PP and PP/FPP suggested that the isothermal crystallization kinetics of PP/FPP blends followed a three-dimensional growth via heterogeneous nucleation. In terms of the half-time of the crystallization, t_1/2, the crystallization rate of functional PP blends was faster than that of PP homopolymer at a given crystallization temperature.     

Direct synthesis of electrorheological suspension containing salt of poly(methacrylic acid) and its electrorheological effect

Colloidal suspensions containing salts of poly(methacrylic acid) which exhibit high electrorheological (ER) activity were synthesized by inverse emulsion polymerization. Factors influencing the ER effect were studied. The results showed that maximum yield stress occurred at optimum amounts of both polymeric stabilizer and crosslinking agent used in the inverse emulsion polymerization as well as a certain water content of the particles, while yield stress increased with electric field strength, average diameter of the particles below 0.9 μm, or the molar ratio of the salt to the acid. The ER activity for the suspensions containing different monovalent counter ions decreased in the following order: Li⁺ > Na⁺ > K⁺ > NH₄⁺. The phenomena were discussed with the ionic polarization mechanism. © 1995 John Wiley & Sons, Inc.     

接受理论视角下的儿童文学翻译

接受理论的基本观点对儿童文学翻译研究也具有一定的启发和借鉴作用:译者在翻译的过程中不仅要尊重原文和原作者.也要尊重译文的目标语读者--儿童,充分考虑儿童读者的期待视野,从而实现原文与译者期待视野、译文与儿童读者期待视野之间的视野融合.     

基于SPH方法的二维水下爆炸冲击载荷计算

水下爆炸包含了一系列复杂的物理过程,这些复杂的物理现象对数值计算提出了很高的要求.介绍了无网格光滑粒子流体动力学(SPH)方法在水下爆炸模拟中的应用,计算了TNT在近似无限水域中爆炸和沉底装药下爆炸产生的冲击波强度,分析了水下爆炸流场参量分布和变化规律,为水下非接触爆炸数值模拟提供参考.     

毛坝1号隧道涌水成因机制分析

公路深埋隧道在施工过程中经常碰到涌突水灾害,它对工程施工及区域环境都有很重要的影响,本文针对毛坝1号隧道出口端发生长大涌突水等问题,通过水文地质综合调查方法,分别从地形地貌、地层岩性、地质构造和隧址区水文地质特征等多角度,论述该隧道在施工过程中发生涌水的成因机制,为今后在类似地质条件下深埋隧道的勘察设计提供借鉴和帮助。     

计算机网络实验室改造与实验教学改革

阐述了计算机实验教学在教育中的重要地位,分析了计算机网络实验室的现状,提出了计算机网络实验室的改造策略以及实验教学改革的措施。     

Facile synthesis of uniform hollow hematite sub-micro spheres with controllable shell thickness

A simple method was developed to prepare the uniform hematite hollow submicro-spheres with controllable structure and different diameter based on monodisperse poly(styrene-co-acrylic acid) [P(St-co-AA)] particles. The structure and formation mechanism of the hollow spheres were investigated in detail. The control mechanism of shell thickness was also discussed. The results indicated that the shell thickness and coarseness of the synthesized core-shell hematite hollow spheres could be tuned simply by the surface carboxyl content of the P(St-co-AA) particles. This method provided a new approach for the structure control in the preparation of hollow spheres. A Brunauer-Emmett-Teller (BET) test shows that the prepared hollow spheres have large surface areas which were decreased along with the increase of the diameter. The magnetic properties of the as-obtained hematite hollow spheres were investigated. The result showed that the coercivity and saturated magnetization were increased along with the increase of the shell thickness, and the remanent magnetization was increased along with the decrease of the diameter.