县级环境监测站实验室内部设计案例简介和分析

本文详细介绍县级环境监测实验室设计原则和理念,并结合作者自己站环境监测实验室建设的实际,对实验室新大楼建设平面布局、实验室排风、实验室供电、实验室纯水系统、实验室特殊气体系统等部分的设计进行了简单介绍,并提出了相关优选方案,为县级同规模环境监测实验室的建设提供借鉴作用。     

Hot extrusion process modeling using a coupled upper bound-finite element method

A thermo-mechanical model has been developed for modeling of hot extrusion processes. Accordingly, an admissible velocity field was first proposed by means of stream function method and then, extrusion pressure as well as temperature variations within the metal and the die were predicted employing a combined upper bound and Petrov–Galerkin finite element analysis. In order to evaluate the model predictions, hot extrusion of AA6061-10%SiC_p was considered under both isothermal and non-isothermal conditions and the predicted force–displacement diagrams under various extrusion conditions were compared with the experimental ones and reasonable consistency was found between the two sets of results.     

美国太阳反射镜步进应力加速老化试验

为了应对降低聚光发电(CSP)成本带来的挑战,研发新型的低成本反射镜材料,包括金属聚合物反射镜。通过将太阳反射镜暴露在紫外光下,利用试验应用方法和统计推论技术,定量评估和改进太阳光反射镜在紫外光下与失效机制相关的使用寿命。将利用超加速环境系统评估由紫外暴露加速老化导致的多种性能退化模式。由于样品数量、试验条件、性能退化和失效模式等原因,试验结果可用于深入推导失效机制、关联物理参数、服役寿命和不确定性。在有必要利用高级方案和统计推论的复杂情况下,建议采用步进应力加速老化试验方法。     

基于极大似然估计的加速因子计算方法

目的在产品寿命服从参数未知指数分布的情况下,分析定时转换步加试验得到的数据,估算相关的加速因子。方法列出各应力下的寿命分布密度函数形式,通过加速因子建立各分布密度函数之间的联系,以条件概率的方式处理步加试验每一阶段开始时的累积损伤问题,以极大似然估计的方法进行参数估计。结果得出了一种新的估算加速因子的方法,计算获得了产品在所分析应力下加速因子与应力水平之间的关系。结论利用该方法能很好地处理某应力下无失效发生的情况。     

Suitability of ignition source “exploding wire” for determination of dust explosion characteristics in the 20-L-sphere

Several safety characteristics of dusts are determined in the 20-L-sphere (also known as SIWEK Chamber) according to international standards. Dust cloud ignition is carried out using pyrotechnical igniters. Due to various disadvantages of such igniters the need for alternative ignition sources arises again and again. An alternative could be an ignition source which is known as “exploding wire” or “fuse wire”. The paper presents test results of a comparative study between both ignition sources for the determination of the safety characteristics “Maximum Explosion Pressure” and “Maximum Rate of Explosion Pressure Rise” of five selected dusts in the 20-L-sphere. In addition to that the ignition mechanisms of both ignition sources were analyzed by high speed camera recordings and the ignition energy was determined with electric and calorimetric recordings. The paper shows results of measurements of the ignition energy of both ignition sources as well as sequences of the flame propagation.     

Measurement Accuracy of the Electrosensitive Protective Device Response Time When Using the Double Penetration Method

The Double Penetration Method (DPM) method of measuring ESPD (Electrosensitive Protective Device) response time was presented by Dzwiarek (1997). Calibrating the measuring equipment is a crucial stage of the procedure. Experimental verification of theoretical predictions is also crucial. For calibration purposes, a device simulating real ESPD operation thus enabling a correct setting of the response time was designed (Dzwiarek, 1997).

Theoretical analysis has shown that measuring ESPD response time with the DPM is subject to localisation errors made in the localisation of the detection zone border, rod position measurement errors made during highspeed penetration, and time delay measurement errors. The values of all those components of the total error have been determined experimentally using the calibrating device. Measurements have been taken under conditions as close to real ones as possible proving that the total measurement error is really enclosed within the assumed limits.     

电驱动道路车辆动力锂离子电池芯试验中的实验室安全和防护

实验室标准化试验的条件远比装车使用严酷得多,在电驱动道路车辆的动力锂离子电池试验的过程中,实验室的安全是不可忽视的问题。基于实践和探索,本文介绍了关于电池芯试验的安全和防护。     

电驱动道路车辆 动力双层电容电气特性试验条件和要求

本文结合国标转化过程和实验室能力验证经历,介绍了电驱动道路车辆动力双层电容电气特性试验条件和要求。供实验室和相关产品的供需双方参考。     

金属材料腐蚀检(监)测常用方法概述

从机械方法、无损检测方法和电化学方法3个方面简要介绍了常用的腐蚀检(监)测方法,并对各种检验方法的特点和适用范围进行了比较.在实际的生产实践中应根据具体情况,依据可靠性和适用性的原则选择合适的方法,从而达到高效、准确的检验目的.     

唐山市某工业厂房全装配式改造更新方案分析

在原有工业厂房的基础上,采用装配式钢框架及梁-墙一体式墙板和可拆卸式剪力墙板对原有工业厂房进行改造更新.钢梁柱节点采用法兰外环板式,新加楼盖板采用预制预应力带肋底板混凝土叠合楼板(简称PKG板),同时与钢框架梁形成钢-混凝土组合梁体系,并与装配式墙板一体化设计,内墙板一部分采用原屋面重型混凝土板调节楼层重心,另一部分采...