输送机托辊间输送带的最大挠度与最小张力的计算

对倾斜带式输送机托辊间输送带的最大挠度与最小张力的分析计算是根据荷载沿水 平跨度均匀分布的悬索进行的,从而推导出最大挠度与最小张力之间的关系式。     

悬浮污泥过滤技术在海外油田采出水回注处理中的应用研究初探

悬浮污泥过滤技术集混凝沉降和过滤于一体。分析了大庆油田和胜利油田采出水处理站悬浮污泥过滤技术的应用效果和存在的问题。介绍了悬浮污泥过滤技术在伊拉克油田采出水处理中的应用现状,分析了影响净化效果的主要因素,并与传统油田采出水处理工艺进行了比较,     

角蛋白与聚合硫酸铁复配体系处理选煤废水的研究

采用单因素实验方法,以选煤废水为研究对象,将鸡毛角蛋白助剂与聚合硫酸铁复配体系用于选煤废水处理,研究复配体系对选煤废水的处理效果。结果表明:复配体系的最佳配置为鸡毛角蛋白助剂0.2 g/L,聚合硫酸铁0.025 g/L,且该复配体系实现了在碱性条件下高效处理选煤废水。该复配体系处理选煤废水的最佳工艺条件为:室温下,选煤废水在pH值为7~8的条件下,投加角蛋白复配体系并搅拌,搅拌速度为120 r/min,反应后沉降30 min,此时,SS(固体悬浮物)去除率达到92%以上。     

油田采出水中悬浮固体含量的测定

针对油田采出水悬浮固体含量的测试过程中暴露出的水样过滤时间长、烘干前滤膜表面滞留水量大导致测试结果重现性差和误差大的问题,提出了单个滤膜极限过滤体积的概念和水样过滤体积确定方法.通过对不同厂家微孔滤膜性能、膜滤速率曲线进行比较,优选了适宜的滤膜,有效地提高了不同实验室之间测试结果的重现性和测试精度.     

Enzymatic membrane reactors: the determining factors in two separate phase operations

A two separate phase‐enzymatic membrane reactor is an attractive process since it has a large interfacial area and exchange surfaces, simultaneous reaction and separation and other benefits. Many factors influence its successful operation, and these include characteristics of the enzyme, membrane, circulating fluids and reactor operations. Although the operating conditions are the main factor, other factors must be considered before, during or after its application. At the initial stage of reactor development, the solubility of substrates and products, type of operation, membrane material and size, enzyme preparation and loading procedure, and cleanliness of the recirculated fluids should be specified. The immobilization site, reactor arrangement, dissolved or no‐solvent operation, classic or emulsion operation and immobilized or suspended enzyme(s) are determined later. Some factors still need further studies. Utilization of the technology is described for use from multigram‐ to plant‐scale capacity to process racemic and achiral compounds. The racemates were resolved primarily by kinetic resolution, but dynamic kinetic resolution has been exploited. The technology focused on hydrolytic reactions, but esterification processes were also exploited. Copyright © 2011 Society of Chemical Industry     

大悬挑钢结构雨篷设计

针对现阶段较为广泛应用的大悬挑钢结构雨篷进行了总结与分类。分析了各个类型的优缺点,总结了雨篷设计所应考虑的荷载、效应等条件,提出了各杆件的控制因素与关键节点设计方式。最后,结合以上各条,对一6m跨悬挑雨篷进行计算分析,给出了具体的计算数据及构件大小,并进行了具体分析对比。     

Valuing vegetation in an urban watershed

This study uses the hedonic price method to examine if land cover types-trees, shrubs, water and impervious surface areas-affect the sale price of single-family residential properties in Multnomah County, Oregon. We combine detailed structural and location information for 36,753 single-family residential property sales with the percentage of land cover on each property and within three buffers surrounding each property. Trees contribute positively to a property's sale price, but the estimated increase may be less than the costs of planting and caring for trees. Benefits received by nearby property owners may justify actions by government agencies to expand canopy coverage.     

林分平均高度卫星遥感新进展

林分平均高度是生态系统模型重要的输入参数之一,与生物量估算与碳循环研究高度相关。通过系统回顾林分平均高度研究的发展历史和最新进展,总结了不同传感器林分平均高度(SAR树高与LiDAR冠层高度)研究的主要模型和方法,通过单一传感器技术进行林分平均高度研究的内在特征的不同,分析了多传感器的区域林分平均高度联合反演方法的优劣性,并从科学发展趋势和社会需求出发,认识目前存在的主要问题与难点及未来面临的挑战和机遇,为今后更好地进行森林垂直结构和全球碳循环研究提供思路和借鉴。     

液压支架顶梁的迭代差分分析

本文按薄板小挠度理论,用迭代差分法分析了液压支架顶梁在若干加载条件下的挠度、内力和应力,给出了相应的最大应力值及其位置,并与实测结果及有限元法分析结果进行了比较。     

平面预应力索-拱体系

本文提出一种新的混合结构形式—预应力索-拱体系,作为传统的双层索系的可能竞争者.这种体系可以施加较小的预拉力,但具有较好的形状稳定性和刚度.本文用连续化理论对平面索-拱体系进行了理论探讨,导出了在常见荷载作用下的内力和位移的计算公式,同时进行了跨度为4.5M的大模型试验,在静力方面考察了体系在不同形式荷载作用下的内力和变位,在动力方面测定了该体系模型的基本动力特征—前五个频率和相应的振型.理论计算结果与试验符合得较好.