Mercury, cadmium and lead concentrations in different ecophysiological groups of earthworms in forest soils

Bioaccumulation of Hg, Cd and Pb by eight ecophysiologically distinct earthworm species was studied in 27 polluted and uncontaminated forest soils. Lowest tissue concentrations of Hg and Cd occurred in epigeic Lumbricus rubellus and highest in endogeic Octolasion cyaneum. Soils dominated by Dendrodrilus rubidus possess a high potential of risk of Pb biomagnification for secondary predators. Bioconcentration factors (soil-earthworm) followed the sequence ranked Cd > Hg > Pb. Ordination plots of redundancy analysis were used to compare HM concentrations in earthworm tissues with soil, leaf litter and root concentrations and with soil pH and CEC. Different ecological categories of earthworms are exposed to Hg, Cd and Pb in the topsoil by atmospheric deposition and accumulate them in their bodies. Species differences in HM concentrations largely reflect differences in food selectivity and niche separation.     

基于社会网络分析的建筑工人不安全行为传播路径研究

为提升建筑施工安全管理水平,基于群体视角分析班组中建筑工人间不安全行为传播路径特点,运用社会网络分析理论构建建筑施工班组成员间不安全行为网络传播模型。以1个钢筋工班组为例,通过问卷调查获得样本数据,对得到的网络模型中网络密度、网络中心势、凝聚力、中心性、核心 边缘结构以及凝聚子群等指标进行量化分析。研究结果表明:建筑工人构成的不安全行为传播网络密度较高,凝聚力较强,不安全行为传播明显;技术工人作为行为领袖处于网络核心位置上,人缘较好的工人处于次级核心位置,班组长以及新工人处于班组边缘位置;不安全行为经由核心处中间人传播到其他工人;班组中存在明显的子群结构。     

一氧化碳作业人员血脂水平的调查

目地:探讨一氧化碳对作业人员血脂水平的影响.方法:以168例一氧化碳作业人员为观察组及97例非接触工人为对照组,分别检测其血脂水平.结果:发现一氧化碳接触组与对照组的甘油三酯水平有显著性差别(P<0.05),低密度脂蛋白水平也显著高于对照组(P<0.01).结论:一氧化碳对作业人员的血脂水平具有一定影响,尤以对低密度脂蛋白影响最为显著,提示应加强对一氧化碳作业人员的心血管系统的监测.     

浅埋隧道下穿超近距密集管线施工变形时空特性研究

为分析浅埋隧道下穿密集管线施工地层与管线群变形时空特性,基于南昌地铁三号线邓埠站1号出入口暗挖隧道工程,利用理论分析、数值分析结合现场监测的方法进行研究。研究结果表明：隧道上方密集管线中位于前方的管线先承担开挖释放的部分土体应力,使其后方管线的变形大幅减小,平均减幅达23%;地层变形始终朝向掌子面,在掌子面到达时水平位移最大;因管线-土体共同作用,土体释放部分应力转移到地下管线,使地层沉降减小24%～38%,沉降槽宽度扩大40%;施工期间建议对污水管变形重点监测,在管线平均变形速率急速增大时,需提高监测频率。研究结果可为该地区相似工程施工提供参考。     

Proposal for a Transatlantic Platform for Consumer Concerns and International Trade

Consumer concerns pop up. They are relatedto the safety of agrifood products for people, foranimals, and for the environment as well as the socialand ethical implications of certain agrifoodproduction methods. At first sight, the WTO agreementand the SPS and TBT agreements appear to offersufficient legal scope to deal with these concerns andresolve trade conflicts. The events of recent years,however, have shown the limitations of theseagreements in dealing with cultural differencesbetween nations and in dealing with the social andpolitical pressure on national governments to lay downrestrictive, trade distorting measures. It is vitalthat we consider the dynamic relationship betweennational governments, civil society, and the market.In the United States, Canada, and Europe, thisrealization is growing. We propose that these issuesshould be studied by experts in several disciplines:technical experts, hygiene experts and veterinarians,public administration experts, lawyers, philosophers,ethicists, sociologists, and, of course, economists.To unite these disciplines and provide a platform fordiscussion in the light of international tradeliberalisation, the cultural identity of distinctcommunities, and the functioning of the democraticnation state an international network is needed. Wetherefore propose establishing a network to explorethe issues and dynamics described above. The networkshould be international and interdisciplinary withparticipants, initially, from science and government.The purpose of the network would be to present newperspectives to the negotiating parties in the nextWTO round. The first steps to development of thisnetwork have since been taken and an initial group hasbeen established.     

ZnCl_2溶液对褐煤半焦表面性质及其中高温脱汞性能的影响

利用ZnCl_2溶液对褐煤进行浸渍后在700℃条件下热解制备改性半焦,采用N2吸附/脱附、傅里叶变换红外光谱、X射线光电子能谱等手段对ZnCl_2处理前后两种半焦表面物化性质进行了表征,在小型固定床反应器上研究了ZnCl_2溶液浸渍处理前后褐煤半焦对气态单质汞(Hg~0)的脱除性能.结果表明,经过ZnCl_2处理得到的半焦(ZSC)具有发达的孔隙结构,其表面含氧官能团含量和数量有所提高,并出现了新的C-Cl基团;在100~360℃温度范围内,制备的改性半焦ZSC的脱汞效率随温度升高而降低,但在中高温条件下仍表现出良好的脱汞性能;在化学吸附过程中,气态Hg0被C-Cl基团氧化为HgCl或HgCl_2,同时Hg~0与半焦表面含氧官能团结合生成HgO,Hg~0最终以HgCl_2或HgO的形式附着在半焦表面.     

广西大石围天坑群地下河水中多环芳烃的污染特征

为了确定典型喀斯特区广西大石围天坑群地下河多环芳烃的组成、来源及污染特征,沿途采集了8个断面的表层水样品,利用GC-MS仪测试了16种优控多环芳烃（PAHs）.结果表明, 地下河水中PAHs(总量PAHs)浓度为54.7～192.0 ng/L,平均值为102.3 ng/L, PAHs组成以2～3环为主,占65.1%. 地下河沿程水中的PAHs浓度变化表明,上游高于下游,是因为城镇污水的排放,同时地下河对4～6环PAHs具有吸附作用;大石围天坑断面的PAHs浓度显著增高93.8%,是由于地下河系统中环境介质的释放和大气传输;大石围支流汇合处的PAHs浓度被稀释降低了47.3%;百朗出口断面的PAHs浓度分别高于进口和大石围断面128.3%和17.8%. PAHs来源分析表明,城镇和大石围天坑区域显示以石油类及其燃烧源为主.然而,城镇的石油类源主要是人为输入,大石围天坑的则主要是天然输入;其余乡村地区显示以草木、煤燃烧源为主.与其他地区比较,大石围天坑群地下河水中PAHs污染处于较低的水平,但苯并［a］芘浓度6个断面超过国家地表水环境质量标准.     

大肠菌群革兰氏染色技术的实验研究

针对影响革兰氏染色正确性的几个因素,通过比较实验,研究了在大肠菌群测定过程中菌龄、细菌密集程度、媒染时间、脱色程度等因素对革兰氏染色正确性的影响,从而得出一最佳革兰氏染色条件组合,并提出了确证革兰氏染色技术操作正确的方法。     

基于多准则群体决策模型的生态工业园区建设模式决策研究

将层次分析法和系统聚类法相结合,构建了多准则群体决策模型,对生态工业园区(EIP)建设模式的决策进行了探讨.从影响EIP建设模式决策的建场基本条件、经济效益、环境影响及社会制约因素等出发,建立多准则的层次分析模型,运用系统聚类分析对专家群进行分类,对于人数多的类赋予较大的权重系数,最后计算了综合多数专家意见的群体决策的判断权重,得出EIP建设模式的先后次序.将该法应用于郑州市惠济区的实证分析,9位专家进行群体决策,新建型、改造型、虚拟型EIP的综合权重分别为0.206,0.322和0.472,故惠济区的最佳建设模式是建设虚拟型EIP,该结果符合当地实际情况.该模型可综合专家决策意见,使结果更为可靠,可为其他EIP建设模式的决策问题提供借鉴.      

Meta-analysis of the effect of low-level occupational benzene exposure on human peripheral blood leukocyte counts in China

To investigate the effect of low-level occupational benzene exposure on human peripheral blood leukocyte counts of the workers, domestic and foreign published research data on the change of human peripheral blood leukocyte counts under low-level occupational benzene exposure from January 1990 to December 2020 were collected and analyzed. According to the literature inclusion and exclusion criteria, 18 independent studies from 12 publications were selected for meta-analysis to explore the effect ...