房屋建筑结构无损检测方法的分析与展望

通过对现有的结构无损检测方法的总结和分析,讨论了各种方法的优缺点.并结合现场测试的要求,展望结构检测技术的发展方向与趋势.     

Comments on the shortcomings of predicting the precision of Cavalieri volume estimates based upon assumed measurement functions

It is well known that the estimation of an object's volume by means of serial cross-sections, the so-called Cavalieri method, yields an unbiased estimate. But by itself it provides no means by which to estimate how precise this estimate is unless the shape of the volume is fully known beforehand. This knowledge can only be partially determined from the serial section information that is collected. Methods have been developed that claim to surmount this difficulty by using the serial section data to create a mathematical model of the volume's shape properties. The model then is used to estimate (predict) the precision of the volume estimate (its CE) from the single set of data available. Unfortunately, the theory underlying the model is flawed and so the model itself amounts to no more than an unsubstantiated guess about the shape of the volume. Therefore, the precision of the volume estimates that one obtains from the method is only as good as the model and this cannot be ascertained from the single set of acquired data. In this letter I explain the inadequacies of the modelling method. I suggest that it be used only with caution, if at all. Instead I suggest two alternative ways to predict the CE, one that is based upon a rule-of-thumb approach to the object's shape, and another that is based upon spectral analysis of the measurement function and that is easy to implement with available computer software.     

海洋石油开发工业污染物产生系数和排放系数研究

污染物产生系数和排放系数是工程环境影响评价的重要指标,但对于海洋石油开发工程环境影响评价来说,迄今尚无具权威性的系数可资使用。在我国近海石油开发工程污染源系统调查的基础上,对海洋石油开发行业污染物产生系数和排放系数的定义、计算方法、应用范围及应用方式进行了探讨,研究结果可为海洋石油开发工程项目环境影响评价及环境保护管理,以及行业或企业有关标准的制定提供参考。     

油罐清洗作业防火安全措施

目前大型原油储罐逐步应用自动机械清洗系统进行清罐作业,而对于容量小、沉积物较少的油罐国内仍采用人工清洗方式进行。分析了油罐人工清洗作业过程时容易引发火灾的原因,并提出相应的预防火灾措施。     

阳离子化多元醇防塌剂的研制

室内研究和现场应用表明,聚乙烯醇类防塌剂表现出较明显的增粘负效应,可引起钻井液粘度的急剧增加,严重影响其推广应用.通过金属盐催化降解和阳离子化反应,研制出了抑制性好且增粘负效应低的阳离子化改性多元醇防塌剂.考察了阳离子化试剂、反应温度、反应时间对取代度、反应效率和产品主要性能的影响,得出了阳离子化多元醇防塌剂最佳制备条件,即：PVA与阳离子化试剂物质的量比为1：1,反应温度为50℃,反应时间为4 h,阳离子度可达0.435.     

高压注水管柱受力分析

进行高压注水管柱受力分析的目的就是根据注水条件研究注水管柱在不同过程中的各类效应，以及这些效应对管柱产生的受力和变形规律，从而明确注水管柱的工作状态，保障注水管柱有效合理地工作。较详细地分析了高压注水管柱在锚定、坐封以及注水3个过程中的受力状态和变形情况，并分析了高压注水管柱在不同过程中受到的各种效应的影响，推导出注水管柱在不同过程中的应力及变形的计算公式，并给出了算例。     

Growth and optical property of zinc oxide thornballs

A new microstructure, thornball, of zinc oxide (ZnO) was synthesized by a very simple solid vapor deposition process under lead oxide (PbO) atmosphere. The microthornballs consist of numerous needles, which extend outwards in all directions symmetrically. They have dimensions of 120 μm in diameter, while the average diameter of the needles is about 100-200 nm. The needles on the balls grow along the 〈0 0 0 1〉 orientation and have gradient compositions along radial. Control experiments proved that PbO played an important role in the growth. Additionally, photoluminescence property was observed and provided the evidence that PbO did not deteriorate the optical properties of ZnO thornballs. This kind of microstructures has potential applications in the field of photochemical catalysis.     

给水铜管分水布置的支管缩径可行性分析

住宅给水铜管分水布置是一种技术可行、经济合理的管道布置方式。在确定了管道的设计要求后,分析了分水缩径后的流速情况,明确了分水布置方式中支管缩径的技术状况。分析表明,支管缩径是可行的。     

智能化系统在新火车站的应用——福州火车站智能化系统设计总结

福州火车站智能化系统包括到发通告、旅客引导显示、客运广播、建筑设备自动控制等7个子系统和系统总集成。