Elastic field and effective moduli of periodic composites with arbitrary inhomogeneity distribution

This paper develops a semi-analytic model for periodically structured composites, of which each period contains an arbitrary distribution of particles/fibers or inhomogeneities in a three-dimensional space. The inhomogeneities can be of arbitrary shape and have multiple phases. The model is developed using the Equivalent Inclusion Method in conjunction with a fast Fourier Transform algorithm and the Conjugate Gradient Method. The interactions among inhomogeneities within one computational period are fully taken into account. An accurate knowledge of the stress field of the composite is obtained by setting the computational period to contain one or more structural periods of the composite. The effective moduli of the composite are calculated from average stresses and elastic strains. The model is used to analyze the stress field and effective moduli of anisotropic composites that have cubic symmetry. It shows that the bulk and shear moduli predicted by the present model are well located within the Hashin-Shtrikman bounds. The study also shows that the stress field of the composite can be significantly affected by the distribution of inhomogeneities even though the effective moduli are not affected much.     

Mechanically strong conducting hydrogels with special double-network structure

Mechanically strong conducting hydrogels composed of poly(acrylamide) (PAAm) and poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT-PSS) have been synthesized through the construction of a special double-network (sDN) structure. The novelty of the sDN hydrogels lies in the introduction of PEDOT-PSS semi-interpenetrating polymer network (semi-IPN) hydrogel as the second network. Based on the experimental results and the double-network theory, an additional strengthening effect resulting from the formation of the PEDOT clusters in a three-step fracture process is proposed. The applicability of as-prepared PAAm/PEDOT-PSS sDN hydrogels in electromechanical actuators is also briefly discussed.     

水热法制备粉煤灰钙基脱硫剂

文章研究了利用粉煤灰和Ca(OH)2为原料水热反应制备钙基脱硫剂。影响钙基脱硫剂钙剂利用率最主要的因素是水浴温度(TH),它的最佳值是90℃;温度上下浮动5℃,利用率将降低20%。其次还有水浴温度、粉煤灰与Ca(OH)2质量比(FC)、水固比(LS),这些因素的波动对利用率的影响相对较小。水浴时间(tH)达到8 h以上,FC在5～10的范围内变化,LS在8～18的范围内变化均能制备具有较高利用率的钙基脱硫剂。     

MEUF去除废水中重金属和有机物及其浓缩液的处理

胶团强化超滤(MEUF)是一种表面活性剂和超滤相结合的处理含重金属或有机污染物废水的新技术。详细介绍了MEUF技术的原理、表面活性剂的选择、影响处理效果的主要因素,同时针对MEUF技术目前存在的浓缩液处理和表面活性剂回收的问题作了详细的阐述,综述了近年来MEUF技术应用的最新研究成果,并就此技术存在的问题和发展前景作了相关分析,实践表明该技术具有很好的应用前景。     

基层设备管理中的专业考核问题

在基层设备管理中,建立以案例考核为主体的考核体系,采用多种激励手段,实现设备管理的有效性和经济性。     

数字化测图与模拟法测图的比较与认识

随着测绘科学技术的发展,传统的模拟法测图方法已被数字化测图方法所替代.文中从数字化测图工作的外业、内业以及测量成果表现形式上,对数字化测图与模拟法测图的特点进行了对比分析;分析了数字化测图质量评价的内容和特点;结合数字化测图的工作实践,对数字化测图工作获得了有益的认识.     

泡沫玻璃在房屋建筑中的应用及其施工质量控制

本文主要介绍了一种新型的、可用于节能窗玻璃或是建筑维护结构的保温隔热材料——泡沫玻璃,对其主要物理性能、分类、应用技术特点进行了简要分析,并对其在房屋建筑工程应用中的施工准备和施工过程的质量控制进行阐述,以供参考。     

储罐底板提离试验及数值模拟分析

对模型储罐进行振动台试验,测试储罐的位移地震响应,在此基础上运用大型有限元分析软件ADINA对模型储罐地震动响应进行了底板提离数值仿真分析。分析结果表明:无论是小体积罐还是大体积罐,在一定的地震强度下均可能发生提离,而且储罐发生提离的时刻大多数是在地震波的峰值过后发生的。底板提离区域为月牙形,提离位移沿环向的分布随不同的时刻改变。     

城市快速公交车站点式玻璃幕墙的应用

针对当前城市化建设步伐的加快,城市道路交通拥挤日益凸显的难题,提出了快速公交系统是未来城市公交发展方向的理念,并详细介绍了该系统中点式玻璃幕墙的组成、特点及应用效果。     

CPG500长轨条铺轨机组车载龙门吊配套研究

车载龙门吊作为CPG500型长轨条铺轨机组的重要组成部分,承担着倒运轨枕,给机组不断添加用料的重任,其技术性能直接关系到整机的安全、效率和可靠性等主要性能指标。因此,车载龙门吊的深入研究对于长轨条铺轨机组的技术经济性能突破有着重要的作用和意义。