Endocrine modulation and toxic effects of two commonly used UV screens on the aquatic invertebrates Potamopyrgus antipodarum and Lumbriculus variegatus

The two UV screens 3-benzylidene-camphor (3-BC) and 3-(4'-methylbenzylidene)-camphor (4-MBC) were tested regarding their toxicity and estrogenic activity. The Yeast Estrogen Screen (YES) and two sediment assays with the freshwater invertebrates Lumbriculus variegatus and Potamopyrgus antipodarum were performed. In the YES, both substances activated the human estrogen receptor alpha with EC50 values of 44.2 microM for 3-BC and 44.3 microM for 4-MBC, whereby 4-MBC attained only 8% of the maximal response of 17beta-estradiol. For P. antipodarum embryo production increased after exposure to both substances (EC50 of 4.60 microM 4-MBC=1.17 mg kg(-1)dw) while mortality increased at high concentrations. The reproduction of L. variegatus was decreased by 3-BC with an EC50 of 5.95 microM (=1.43 mg kg(-1)dw) and also by 4-MBC, where no EC50 could be calculated. While reproduction decreased, the worms' weight increased after exposure to 3-BC with an EC50 of 26.9 microM (=6.46 mg kg(-1) dw), hence the total biomass remained unaffected.     

硝酸盐对富磷剩余污泥厌氧消化的影响试验

以某采用 A/O 生物除磷工艺水质净化厂排出的富磷剩余污泥为研究对象,利用棕色消化瓶设计了 4 组厌氧消化试验,通过向其中投加NaNO3,考察硝酸盐对污泥消化过程的影响.结果表明,硝酸盐的存在导致 VSS 平均变化速率比空白样快 28.09 mg/(L·d),并且对污泥消化过程中的产甲烷阶段有一定的抑制作用;当硝酸盐存在时,厌氧氨氧化作用的发生导致上清液中的 N-NH4 变化速率减慢,硝酸盐对污泥消化过程中磷的释放有明显的抑制作用,当硝酸盐浓度高于 60 mg/L时,抑制作用明显.     

基于GDS的非饱和土强度三轴试验研究

由于吸力的影响,非饱和土的力学性状与饱和土有着很大的差异。文章应用GDS三轴仪来研究某高心墙堆石坝填料非饱和土的强度特征。结果表明:此填料非饱和土的强度在低吸力范围内,与吸力基本呈线性增长关系。验证了非饱和土的双变量强度理论的适用性;并得到了非饱和土抗剪强度参数φb约为10.1°。     

粉末涂料环境试验的重要性及方法

粉末涂料喷涂上工件后,涂层即被赋予了一定的物理化学性能,这些性能在外部自然环境中,经过一段时间会发生哪些变化,涂层最终失去效用要多长时间,哪些因素对涂层的破坏性最强等等,这些都是大家非常关注的。本文简单讨论了粉末涂料环境试验的重要性,介绍了一些实际应用中环境试验的方法及其评级标准。     

医用电气设备电源变压器的过载试验

采用电阻法测量医用电气设备电源变压器过载试验时的绕组温升,试验电流和试验时间的选取与熔断器、过流释放器、热断路器等保护装置有关。     

虚拟仪器在机械振动试验台检测中的应用

本文介绍了基于LabVIEW虚拟仪器的机械式振动试验台检测系统的构成,工作流程和LabVIEW在其中的应用,以此展示虚拟仪器技术使得现代检测系统变得更加简单、方便、有效。     

温、湿度试验中结露的产生与预防措施探讨

从环境试验的概念出发,简要介绍了温、湿度试验中结露的危害,通过对结露产生的原因进行理论上的分析,给出了几种常见温、湿度变化模式下结露的避免方法。     

The utilization of brackish water, protecting the quality of the upper fresh water layer in coastal aquifers

Increasing salinity is one of the most significant and widespread forms of groundwater pollution in coastal areas. This paper presents the causes and impacts of saline water intrusion in coastal areas. Various causes of salt water intrusion, and approaches for the determination of its extent and various measures to control the salt water intrusion are described. An aquifer performance test (APT) approach is presented to identify the extent of existing salt water intrusion in the study area located in the southwest coastal region of Gujarat State (India). A resistivity based experimental technique is used to identify the quality of the groundwater available at different depths. A methodology is presented to assess the extent of available fresh and saline groundwater and to find out the limit up to which lower saline groundwater can be withdrawn for industrial purposes without affecting the upper fresh water layer which can be made available for domestic purposes.     

国内外枪械自然环境试验概况

简要介绍国内外的枪械环境试验管理及枪械的自然环境试验情况,建议将环境工程的概念纳入到枪械设计制造中,努力提高枪械环境适应性,打造我国的世界名枪。     

材料和产品大气暴露与人工加速试验相关性的探讨意见(上)

应用人工加速气候与自然或实际大气暴露试验的实例,说明研究两者相关性的可能性和实际应用意义,并概述高分子材料进行人工加速和湿热自然大气暴露的对比结果,分析探求人工加速气候与自然或实际大气暴露试验两者相关性的主要因素。