汞冶金中防治汞毒污染的主要措施

目前,国内外汞生产均以火法为主。汞的毒源主要是金属汞蒸气,它直接危害人体健康和污染空气,其次是含汞废渣、废水也污染环境。金属汞进入人体有三种渠道:一是呈汞蒸气形态通过呼吸道进入。二是呈液化态金属通过消化系统进入,主要是用带汞的污手吃食物或抽烟等所致。三是汞微粒穿过皮肤进入(由于皮肤破裂和穿戴被汞污染的劳保     

西昌市13种野生蘑菇中汞含量分析及安全性评价

地球生态系统汞的水平一般非常低,但某些大型真菌对汞的强烈积累则是例外.分析了采集于四川省西昌市未受汞污染地方生长的13种野生蘑菇99个样品子实体中汞的含量,用原子荧光法测定蘑菇和蘑菇采集地土壤中的汞含量.野生蘑菇的汞含量随蘑菇种类的不同而不同,双色牛肝菌积累汞的能力最强,质量比为0.99 mg Hg/(kg·dw),生物富集常数(BCF)达2.01.提出野生蘑菇对汞的积累明显受介质汞水平的影响.分析的汞含量与早期的文献数据报道进行比较,评价了法律规定的人体吸收汞水平和食用蘑菇对人体汞吸收量的贡献,指出人们在消费蘑菇时可能存在的风险和应对措施.     

西昌市13种野生蘑菇中汞含量分析及安全性评价

地球生态系统汞的水平一般非常低,但某些大型真菌对汞的强烈积累则是例外.分析了采集于四川省西昌市未受汞污染地方生长的13种野生蘑菇99个样品子实体中汞的含量,用原子荧光法测定蘑菇和蘑菇采集地土壤中的汞含量.野生蘑菇的汞含量随蘑菇种类的不同而不同,双色牛肝菌积累汞的能力最强,质量比为0.99 mg Hg/(kg·dw),生物富集常数(BCF)达2.01.提出野生蘑菇对汞的积累明显受介质汞水平的影响.分析的汞含量与早期的文献数据报道进行比较,评价了法律规定的人体吸收汞水平和食用蘑菇对人体汞吸收量的贡献,指出人们在消费蘑菇时可能存在的风险和应对措施.     

汞净化材料的研制

汞是毒性很大的液态金属,即使在低温下也能蒸发,存在于空气中。人体吸入后难以排出,长期接触、积蓄会造成急性或慢性汞中毒。目前国内外采用过硫酸铵、高锰酸钾、硫酸软锰矿、硫化钠等作吸收液来净化含汞气体,净化效率可达到90％以上,但吸收液和沉淀物的后处理困难,并会带来废水和废渣的二次污染。也有采用氯化活性炭干法净化汞蒸气的,虽净化效率高,但再生困难,     

无汞电池除汞害

广州电池厂坚持科学实验,采用氯化铋代替氯化汞生 产 电池,使电池工业长期没有解决的汞害问题得到解决。 生产电池的传统工艺,是用氯化汞作为锌亮的缓蚀剂。在生产过程中,氯化汞扩散到空气中,被工人吸到体内,或通过皮肤接触进入体内,就会造成汞中毒或汞吸收,危害工人身体健康。不用氯化汞生产电池行不行?曾经有些同志认为不大可能。 广州电池厂为解决这个问题,由党委副书记挂帅,组成了无汞电池攻关小组。他们联系实际,狠批“四人帮”挥舞“白专道路”、“技术第一”等大棒,破坏科研工作的罪行,树立起为革命钻研技术有理、为革命创造科研成果…     

万山汞矿区居民食用大米的汞暴露风险评估

为明确汞矿区大米汞污染对人体的暴露风险,分别运用冷原子荧光技术(CVAFS)和气相色谱冷原子荧光技术(GC-CVAFS)对贵州万山汞矿区大米中总汞(THg)和甲基汞(Me Hg)质量比进行了测定,并借鉴粮农组织/世界卫生组织食品添加剂联合专家委员会(JECFA)和美国国家环保局(USEPA)的计算模型和研究成果,在区域层面上重点探究了汞矿区居民因食用大米而存在的THg和Me Hg暴露风险。结果表明,大米中THg和Me Hg质量比分别为2.83~295.53 ng/g和2.3~43.18 ng/g;居民THg日摄入量和JECFA安全标准下的健康风险指数(HRI)范围为0.02~1.77μg/(kg·d)和0.03~2.49;居民Me Hg日摄入量范围为0.01~0.26μg/(kg·d),JECFA和USEPA安全标准下的HRI范围分别为0.04~1.13和0.1~2.6;模型计算出的人体头发Me Hg质量比范围为0.17~3.11μg/g,分别有5%和38.33%的监测点超出JECFA和USEPA规定的人体发汞的安全限值。大米THg、Me Hg质量比和人体接受大米THg、Me Hg的健康风险均随远离矿坑不同程度地降低。食用大米已经成为矿区居民汞暴露的重要途径,产生的暴露程度与水稻种植位置关系密切,但这种风险目前整体还处于可控范围,需要及时采取相应措施避免风险扩大。     

烟气脱汞技术现状简述

火力发电厂是我国最主要的烟气排放源, 期间微量元素汞将以不同的形式排放到大气中,对环境造成很大的危害.汞控制技术一般分为燃烧前脱汞,燃烧中脱汞及燃烧后脱汞.燃烧后脱汞是汞控制技术的主要方式,近些年研究异常活跃,主要表现在2个方面:一方面加强了各种吸收剂的研究,另一方面加强利用现有的脱硫装置脱汞的研究.     

汞对水生生物的毒性效应研究进展

汞污染因毒性大、致毒结果严重而备受关注,水环境尤其是水源水的汞污染严重威胁人体健康。近年来,国内外对汞的生物毒性进行了广泛深入的研究。归纳了近年来关于汞对水生生物,包括水生植物、鱼类、贝类、藻类及两栖类毒性效应和毒害机理的研究进展,并提出今后不仅要研究不同水生生物对汞形态的转化方式和转化机理,还要进一步寻找对低浓度汞污染最敏感的指示生物和监测指标。     

氧化汞代替液态汞

荧光灯(俗称日光灯)是一种光效高,寿命长,深受广大群众欢迎的室内照明光源。但是,目前荧光灯生产还离不开汞。汞是一种液态金属,常温下即可蒸发,人过多地吸收了汞蒸气就会中毒。轻者头痛、贪睡、记忆力衰退;重者会发生齿龈炎、腹泻、心神不定,颤抖等,对工人的身体健康危害很大。 为控制液态汞的危害,我们从一九七三年七月开始研制以氧化汞代替液态汞生产荧光灯的新工艺,控制了汞的危害。 为什么可以用氧化代替液态汞 荧光灯的生产原以液态汞加入灯管内,供灯管低气压放电之用。液态汞对人的危害十分严重。 1.汞在常温下即可蒸发,产生汞蒸汽。…     

长三角和珠三角土壤中汞的化学形态、转化和吸附特性

为了解长江三角洲和珠江三角洲农业土壤中汞的积累可能产生的环境影响,选择10个代表性农业土壤样品,研究了土壤中汞的化学形态、积累过程中形态的转化及吸附-解吸行为.研究表明,当无外源汞加入时,长江三角洲和珠江三角洲农业土壤中,汞主要以稳定的残余态形式存在.但随着汞加入量的增加,土壤中可交换态汞显著增加,增加程度与土壤性质有关.土壤pH是影响土壤汞有效性最重要的因素,其对土壤汞的吸附、解吸、形态转化和存在形态均有很大影响.土壤酸化可促进土壤汞的释放,加剧对环境的危害,防治土壤酸化也可有效降低土壤中汞对环境的危害.     

油浸变压器排油注氮装置在500kV变电站的设计与应用

在分析500kV变电站主变压器消防系统的现状,比较3类消防系统优缺点的基础上,详细论述了主变排油注氮装置的结构组成、工作原理、参数计算、控制系统设计以及需要注意的事项等,为下一步排油注氮装置的推广应用打下基础.     

HAZOP结合What-if方法在某延迟焦化装置除焦中的应用

为克服传统危险与可操作性（HAZOP）定性分析方法在复杂操作、间歇作业等过程中使用的局限性,提出在传统HAZOP定性分析方法的基础上结合What-if（故障假设）方法,对人的不安全行为和操作规程不完备所导致的风险后果分析作出补充。详细说明其技术原理、工作流程等使用细节,系统阐述该方法与传统HAZOP定性分析方法的区别,并在某延迟焦化装置的除焦操作的风险分析中应用。经分析,识别出在“给水-泡焦”节点,有“操作规程错误”场景2项,“操作规程不具体”场景1项,不存在“操作人员未按操作规程执行”场景。研究结果表明:本文方法有效且具有较好效果,可以广泛应用于操作规程/作业指导书审查、作业过程隐患排查等方面,帮助企业开展操作层面的风险识别与管理,提升企业的生产安全水平。     

潞安矿区煤层渗透率的各向异性特征实验研究

为了研究原位煤体渗透性的各向异性特征,以山西潞安常村矿3号煤层圆柱试样为对象,利用TCQT-Ⅲ型低渗煤层气相驱替增产试验装置,对煤样进行加载,并以氮气注入压力2.0 MPa的条件下,分析垂直层理和平行层理2个方向的煤体变形和渗透率变化特征。实验结果表明:煤样在加载过程中,平行和垂直层理煤样渗透率均随着有效应力的增大而减小,平行层理方向的渗透率始终大于垂直层理方向,应力加载初期渗透率急剧下降,最后逐渐趋于平缓;径向应变的增加量与渗透率呈正相关性,且平行层理相关性大于垂直层理;沿平行层理方向的裂隙度大于沿垂直层理方向,沿垂直层理方向的应变量大于沿平行层理方向;应变增加量均随有效应力的增加而逐渐减小。研究结果可为煤层井网布置及优化提供参考。     

Nighttime pedestrian fatalities: A comprehensive examination of infrastructure,user, vehicle,and situational factors

Introduction: Pedestrian fatalities in the United States increased 45.5% between 2009 and 2017. More than 85% of those additional pedestrian fatalities occurred at night. Method: We examine Fatality Analysis Reporting System (FARS) data for fatal pedestrian crashes that occurred in the dark between 2002 and 2017. Within-variable and before/after examinations of crashes in terms of infrastructure, user, vehicle, and situational characteristics are performed with one-way analysis of variance (ANOVA) and two-sample t-tests. We model changes in crash characteristic proportions between 2002–2009 and 2010–2017 using linear regressions and test for autocorrelation with Breusch-Godfrey tests. Results: The increase in fatal nighttime pedestrian crashes is most strongly correlated with infrastructure factors: non-intersection unmarked locations (saw 80.8% of additional fatalities); 40–45 mph roads (54.6%); five-lane roads (40.7%); urban (99.7%); and arterials (81.1%). In addition, SUVs were involved in 39.7% of additional fatalities, overrepresenting their share of the fleet. Increased pedestrian alcohol and drug involvement warrant further investigation. The age of pedestrians killed increased more (18.1%) than the national average (3.2%). Conclusions: By identifying factors related to the increase in nighttime pedestrian fatalities, this work constitutes a vital first step in making our streets safer for pedestrians. Practical Applications: More research is needed to understand the efficacy of different solutions, but this paper provides guidance for such future research. Engineering solutions such as road diets or traffic calming may be used to improve identified infrastructure issues by reducing vehicle speeds and road widths. Rethinking vehicle design, especially high front profiles, may improve vehicle issues. However, the problems giving rise to these pedestrian fatalities are likely a result of not only engineering issues but also interrelated social and political factors. Solutions may be correspondingly comprehensive, employing non-linear, systems-based approaches such as Safe Systems.     

Footedness and Mounting—Short Review and Two Case Studies

Footedness is a personal quality like handedness. Footedness may be associated with moving ability during mounting, dismounting, and jumping movements. Occupational accidents have occurred during movement at different working levels, during the use of access and exit systems, and during the mounting of vehicles. Aging can also affect accident risk and body laterality. For example, falling accidents on stairs are common among the elderly. One reason for accidents may be that the structure of the access system or stair system is unsuitable for individual moving patterns depending partly on body laterality. Footedness and the way the feet are used may be contradictory to the demands of the moving situation, especially during uncommon or rapid situations. This contradiction may trigger disturbance during moving. The aims of this pilot study were (a) to review the literature briefly and (b) to describe the use of the dominant and nondominant foot by farmers and the elderly when mounting a tractor and stairs, respectively. The study also gives ideas for future studies based on both (a) and (b).     

AHP与GA-SVM耦合模型在滑坡预警中的应用*

为了减少滑坡造成的损失,提高滑坡预测的准确性,通过搭建灾害模拟平台获得滑坡的实验数据,在获得多组模拟实验数据后,分析各变量的特性。首先,通过层次分析(Analytic Hierarchy Process,AHP)算法,对滑坡进行危险度划分;然后,通过支持向量机(Support Vector Machine,SVM)建立模型,遗传算法(Genetic Algorithm,GA)再优化SVM参数,提出1种层次分析法与GA-SVM相耦合的模型。研究结果表明:AHP方法划分后的数据,通过GA与SVM结合建立的模型精度较好,实验预测结果与实际结果较为吻合,与单一SVM相比,精度更高,结果更好,更加适用于多变量的复杂非线性滑坡预警。     

Debunking the false dichotomy of leadership idealism and pragmatism: Critical evaluation and support of newer genre leadership theories

Leadership theories have shifted over the last few decades from a focus on managerial functions and economic leader–follower exchanges toward greater focus on the interpersonal dynamics occurring within the leadership process. Theories such as transformational, ethical, authentic, and other “newer genre” theories were created to address neglected topics such as leader vision and inspirational messages, transparency, emotional effects, morality, individualized attention, and intellectual stimulation. Critiques of these theories, however, have been raised. In this paper, we address five of those critiques and argue for the validity and practical effectiveness of the new genre theories. Further, we describe how newer genre leadership research should be viewed as a performative epistemology, entailing a process of co‐creation involving scholars and practitioners. Finally, from this view, we provide general ideas for leader development. Copyright © 2014 John Wiley & Sons, Ltd.     

Occupational Safety and Health in Finland

In Finland, occupational safety is the responsibility of the employer, while the occupational safety and health laws are enforced by the Labour Inspection Service, an organization of the state. The Labour Inspection is divided in 11 administrative districts, and it employs 360 professionals. They are mandated to carry out site visits without prearranged appointments to inspect safe work situations, working hours, construction safety, or any aspect of accident risks. The inspectors are also mandated to verify the existence of sufficient occupational health services as prescribed by the Occupational Health Services Act for all employees. The occupational health services are typically provided by enterprise-owned medical departments, by mutually owned health care centers, by private practitioners, or by municipal health care centers. The latter are required by law to provide all services as prescribed by the legislation to anyone who comes to the facility. This situation is prevalent in the countryside, where there are very few private caregiving centers. Declaring occupational accidents and disease cases is mandatory, and the Inspection districts examine all accidents to establish causes and consequences, and to initiate prosecution in case of criminal negligence. Labour Inspection Districts are also notified of the new occupational disease cases as they are declared to insurance companies. Insurance for occupational disease, accidents, and death is an obligation of the employer, although they can choose the insurance company. The medical confidentiality between the workers and their occupational health care providers is very strict. Official statistics are maintained by the state Statistics Finland organization, and they may be used, for example, for research purposes by scientific institutes like the Finnish Institute of Occupational Health. Construction industry accounts for 25% of all fatal accidents (120 cases per 1 million working hours), followed by mechanical, wood, metal, machinery, and pulp and paper industry (10% each of fatal accidents) with rates ranging from 100–160 cases per 1 million working hours. There are some 5,000 occupational disease cases per year (rate 22/10,000 employed). The major disease categories include repetitive strain injuries (1,300 cases), respiratory allergies (600 cases), occupational skin diseases (1,000 cases), and 900 cases of noise-caused hearing loss. In 1998, 589 cases of asbestos-related diseases were reported.     

森林地表火蔓延模拟方法及其计算机实现

进行了森林火蔓延的研究,对传统的经验公式和模型进行改进,明显发现改进的模型有更好的结果,用计算机巧妙准确地实现了模拟模型,在风力不是特别大,地形变化不是特别剧烈时,该模型有较高精度;并结合火蔓延的主要因素（气象因子、气候、地形等）,进行系统分析,写出算地,编制实现地表火蔓延的预测预报计算机系统软件。这对于有效的组织扑救、减少火灾损失、计算森林火灾的损失评估有重要意义。     

公路隧道火灾逃生疏散研究

以苍岭隧道为背景,首先采用经验计算理论和计算软件building EXODUS相结合的方式,从被困人员的安全疏散时间、高温烟气的影响、隧道横通道的利用率以及人员的疏散行为特性进行了研究。结果表明:中小规模火灾情况下的安全疏散时间控制在8 min之内,高温烟气影响不大,但横通道的利用率不平均,且人员疏散路线相对集中。然后对存在的逃生疏散问题提出针对性建议以及其他相关建议,旨在为更大程度降低事故的严重性和经济财产损失。