高层建筑沉降观测及其数据分析

结合某大厦沉降观测的工作实践,介绍了沉降观测的步骤,提出了利用ArcView生成建筑物沉降曲线图的方法,该方法更快捷,内容更确切,外形更美观,从而为决策施工人员提供更准确可靠的信息,总结了沉降观测过程中应该注意的问题。     

二噁英污染现状调查与分析

二噁英是一种有毒的含氯化合物,而且是目前世界上已知的有毒化合物中毒性最强的。二噁英并不是有意生产出来的,而是在工业生产中产生的部分杂质,由于它耐高温、在环境中很稳定等特性,容易造成污染。通过对二噁英的化学特性、二噁英的污染来源、二噁英对环境的污分析,为防止二噁英污染提供一定科学依据。     

Effects of variable thermophysical properties on flow and energy separation in a vortex tube

A numerical study has been conducted to investigate the effects of variable fluid properties on the prediction of a basic tube vortex design. Beforehand, a literature review is presented to highlight some of the recent advances in the enhancements of the device design and its efficiency. The three-dimensional computations with constant and variable properties revealed that the constant thermophysical assumption might not have a dramatic effect if the aim is to predict global values only, but extra caution should be taken for an in-depth flow assessment. The exergy analysis conducted suggests that the highest exergy efficiency, for the current device design, ranges from 38% to 46% depending on the inlet pressure value. Based on the current numerical analysis; rather large exergy losses are due to irreversibility occurring at either; the lowest or the highest cold mass fraction boundary conditions.     

空调系统节能控制有关途径分析

建筑物通风空调系统能量使用受到许多因素影响,实现空调系统节能控制途径也有多种.笔者初步总结了几种途径,在设计运行中有效选择,达到高效、节能的目的.     

Exact elasticity solutions to rotating pressurized axisymmetric vessels made of functionally graded materials (FGM)

In this study the plane elasticity equations of pressurized and rotating structures, generalized analytical closed-form solutions are presented for hollow cylinders, spheres and thin disks. Three well known material pairs are graded in radial direction by using the power rule for various boundary and load conditions. Stress and displacement solutions are obtained. The effect of a constant rotational velocity is also investigated separately in absence of the internal and external pressures. Crucial results are also presented in tabular form.     

浅谈船舶制冷空调安全技术

船舶制冷空调在施工、安装、操作和维护过程中存在着爆炸、中毒、窒息、火灾等一系列危险,需要从多方面进行防范,将安全技术至始至终贯穿于船舶制冷空调设计、施工、操作等每一环节。文章根据笔者多年的从事船舶制冷空调专业的实际工作经验,对船舶制冷空调在设计、施工安装以及维修方面的安全技术,进行了分析,并列举了一些在安全技术方面可供借鉴的实际案例。     

Creep properties of a U‐type notch plate in Ni‐based superalloy

In the present investigation, the effect of notch on creep rupture behavior and creep rupture life of a Ni‐based superalloy has been assessed by performing creep tests on smooth and U‐notched plate specimen under 0°C. The finite element analysis coupled with continuum damage mechanics are carried out to understand the stress distribution across the notch throat and the creep damage evolution under multi‐axial stress state. The creep rupture life of U‐notched specimen is much larger than that of plane plate specimen under the same stress condition, indicating that there is a strengthening effect on notch specimen. Creep rupture life increases with increasing the notch radius, the smaller notch radius can induce the creep rupture easier. The effect of notch on the creep damage is also studied. It is found that the location of the maximum creep damage and the maximum equivalent creep strain initiates first at the notch root and gradually moves to the inside as the notch radius increases.     

Spurenelemente in Halbleitern – eine analytische Herausforderung für die ETV ICP OES

Trace Elements in Semiconductors – A Challenge for the Analysis with ETV ICP OES Direct analysis of solids is characterized by some benefits compared to dissolution‐based methods. Techniques for the direct analysis of semiconductors (Indium phosphide, Silicon carbide, Aluminium nitride, Gallium arsenide) provide an advantageous alternative to methods using wet digestion in sample preparation. The calibration procedure is the major difficulty of all techniques applied for direct solid sample analysis, as there is a lack of suitable reference materials of semiconductors. Calibration was carried out using both dried liquid standards and the analyte‐addition technique. ETV ICP OES can be a powerful technique for the determination of trace elements in semiconductors.     

液粘调速离合器常见故障分析处理

简述了液粘调速器的结构及工作原理,通过对液粘调速离合器调速运行中易出故障的分析,提出应对措施,确保负载(风机、水泵等)在调速工况下的安全运行。