王恭厂灾变的系统研究

1626年5月30日(明天启六年五月初六)北京王恭厂特异灾害事件,成因十分复杂,现象极为奇特。除有明显的地质因素参与外,还有大量的大气静电、龙卷风和火药爆炸作用的痕迹,任何一种单一成因假说都是难以圆满地解释这场灾变的。只有用系统的观点,全面考查灾变时环境系统中各要素的状态、变化及其相互作用,才能深刻地揭示这次灾变的真正原因。人类生存的环境是由岩石圈上部和大气圈下部构成的环境系统,其内各要素相互作用、     

郯城化肥厂噪声治理及效果浅析

介绍郯城化肥厂噪声治理的方法、效果及经验。     

空气细菌采样方法的比较

近20年来,对气挟微生物的研究,无论在环境保护以及劳动卫生方面均已引起人们的广泛重视。在研究方法上,经典的自然落下法已多不采用;液体冲击法虽较科学但操作繁琐;而固体撞击法与滤膜法则较简便,唯前者需特殊采样器,后者仅需气泵及微孔滤膜即可,故简易可行。滤膜法已列为水中大肠菌类监测的     

关于导航设备的环境要求和试验方法

本文简要介绍巴黎会议关于导航设备环境要求和试验方法的讨论情况,并比较现有的各环境规范,介绍我国制订这方面标准的情况。     

小氮肥厂噪声的治理

随着小氮肥工业的发展,噪声污染问题愈来愈引起人们的关切和重视.我厂系5000吨规模的小氮肥厂,现将我们治理噪声、保护环境的做法做一简要介绍. 一、我厂噪声的分布及治理前的污染情况石家庄地区环办曾对我厂生产区噪声进行了两次测定,使用江西红声器材厂生产的NDZ型精密声级计倍频程滤波器.治理前的主要噪声源情况见图一和表一,所列声压级均指A网络.     

扳子坠落与导弹爆炸

一把套筒扳子从高空坠落,会产生怎样的后果?你想象得到吗?报刊上曾经刊载过下面一个故事。 1980年9月18日傍晚7点多钟,离美国阿肯色州马斯克斯镇6公里远的小山上的一个导弹发射井里,维修人员正在对一枚大力神Ⅱ式洲际导弹进行保养作业。这枚导弹的头部装着一颗威力为1,000万吨梯恩梯当量的氢弹头。这时,从距离发射井底21.3米高的工作平台上传来了一声惊叫,原来有个技师不小心将一把1.35公斤重的套筒扳子掉了下去。他紧张地盯着这只扳子,只见它在发射井底部反弹起来,猛地撞击在导弹第一级燃料贮箱的铝合金外壳上。外壳裂开了,液体燃料散发出…     

Particulate emissions from construction activities

Although it has long been recognized that road and building construction activity constitutes an important source of particulate matter (PM) emissions throughout the United States, until recently only limited research has been directed to its characterization. This paper presents the results of PM10 and PM2.5 (particles < or = 10 microm and < or = 2.5 microm in aerodynamic diameter, respectively) emission factor development from the onsite testing of component operations at actual construction sites during the period 1998-2001. Much of the testing effort was directed at earthmoving operations with scrapers, because earthmoving is the most important contributor of PM emissions across the construction industry. Other sources tested were truck loading and dumping of crushed rock and mud and dirt carryout from construction site access points onto adjacent public paved roads. Also tested were the effects of watering for control of scraper travel routes and the use of paved and graveled aprons at construction site access points for reducing mud and dirt carryout. The PM10 emissions from earthmoving were found to be up to an order of magnitude greater than predicted by AP-42 emission factors drawn from other industries. As expected, the observed PM2.5:PM10 emission factor ratios reflected the relative importance of the vehicle exhaust and the resuspended dust components of each type of construction activity. An unexpected finding was that PM2.5 emissions from mud and dirt carryout were much less than anticipated. Finally, the control efficiency of watering of scraper travel routes was found to closely follow a bilinear moisture model.     

Radium isotopes in the Ulsan Bay

In order to estimate the fluxes of Ra isotopes, we measured 224Ra, 226Ra, and 228Ra activities in the Ulsan Bay mixing zone. The convex upwards curvature of the plot of Ra isotope activities versus salinity for the mixing zone suggests that Ra isotopes are supplied from particles entering the mixing zone from both the river and bottom sediments. This addition increases the estuarine flux of 226Ra and 228Ra to the outer sea by factors of 15 and 95 over the flux attributable to Ra dissolved in the riverine water alone. In order to estimate the residence time of the water in Ulsan Bay, we applied a mass balance model to the distribution of 224Ra and 226Ra activities in the Ulsan Bay mixing zone with the inflow from the Taehwa River. The obtained residence times of the waters in the Ulsan Bay were estimated to be 6.8-11.4 d. The waters in the upper part of the estuary have long residence times whereas those in the lower part, in contact with the open sea, have shorter residence times. The mean residence time of the water in the Ulsan Bay was estimated to be 9.1 d.     

Utilization of magnetic and electrostatic separation in the recycling of printed circuit boards scrap

The progress of the technology is directly related to the growth of production and consumption of electrical/electronics equipment, especially of personal computers. This type of equipment has a relatively short average lifetime, 2-3 years. The amount of defective or obsolete equipment has been increasing substantially; consequently its disposition and/or recycling should be studied. In this work, printed circuit boards, which are used in personal computers, were studied in order to recover the metals in the circuit boards through mechanical processing, such as crushing, screening, as well as magnetic and electrostatic separation. The results obtained demonstrate the feasibility of using these processes to separate metal fractions from polymers and ceramics, and that it is possible to obtain a fraction concentrated in metals containing more than 50% on average of copper, 24% of tin and 8% of lead.     

美国烟气脱硫新技术-炉内注入吸着剂法的现状和展望

从六十年代末期开始,各国烟气脱硫方面的开发工作集中在为新建厂寻找高脱除率(70～90%)的工艺上,新选择的技术有烟气洗涤法以及后来发展的喷雾干燥法等.然