Source attributions of heavy metals in rice plant along highway in Eastern China

Air and soil pollution from traffic has been considered as a critical issue to crop production and food safety, however, few efforts have been paid on distinguish the source origin of traffic-related contaminants in rice plant along highway. Therefore, we investigated metals (Pb, Cd, Cr, Zn and Cu) concentrations and stable Pb isotope ratios in rice plants exposed and unexposed to highway traffic pollution in Eastern China in 2008. Significant differences in metals concentrations between the exposed and unexposed plants existed in leaf for Pb, Cd and Zn, in stem only for Zn, and in grain for Pb and Cd. About 46% of Pb and 41% of Cd in the grain were attributed to the foliar uptake from atmosphere, and there were no obvious contribution of atmosphere to the accumulations of Cr, Zn and Cu in grain. Except for Zn, all of the heavy metals in stem were attributed to the root uptake from soil, although significant accumulations of Pb and Cd from atmosphere existed in leaf. This indicated that different processes existed in the subsequent translocation of foliar-absorbed heavy metals between rice organs. The distinct separation of stable Pb isotope ratios among rice grain, leaf, stem, soil and vehicle exhaust further provided evidences on the different pathways of heavy metal accumulation in rice plant. These results suggested that further more attentions should be paid to the atmospheric deposition of heavy metals from traffic emission when plan crop layout for food safety along highway.     

Role of cosubstrate and bioaccessibility played in the enhanced anaerobic biodegradation of organochlorine pesticides (OCPs) in a paddy soil by nitrate and methyl-β-cyclodextrin amendments

The present study was conducted to investigate the anaerobic biodegradation potential of biostimulation by nitrate (KNO₃) and methyl-β-cyclodextrin (MCD) addition on an aged organochlorine pesticide (OCP)-contaminated paddy soil. After 180 days of incubation, total OCP biodegradation was highest in soil receiving the addition of nitrate and MCD simultaneously and then followed by nitrate addition, MCD addition, and control. The highest biodegradation of chlordanes, hexachlorocyclohexanes, endosulfans, and total OCPs was 74.3, 63.5, 51.2, and 65.1 %, respectively. Meanwhile, MCD addition significantly increased OCP bioaccessibility (p?<?0.05) evaluated by Tenax TA extraction and a three-compartment model method. Moreover, the addition of nitrate and MCD also obtained the highest values of soil microbial activities, including soil microbial biomass carbon and nitrogen, ATP production, denitrifying bacteria count, and nitrate reductase activity. Such similar trend between OCP biodegradation and soil-denitrifying activities suggests a close relationship between OCP biodegradation and N cycling and the indirect/direct involvement of soil microorganisms, especially denitrifying microorganisms in the anaerobic biodegradation of OCPs.     

江苏省海岸带近30年人类干扰指数时空变化特征

为探究县级以上海岸带区域人类干扰指数（human interference index, HII）的时空变化特征及生态意义,本文利用遥感数据和地理信息系统技术,对HII计算方法进行一定的改进,使其更适合大范围研究区的计算,并分析了1990－2020年江苏省海岸带HII的时空变化特征及其关键驱动因素,最后以HII与选取的代表性指标的相关性分析结果探讨了HII的生态意义。研究结果表明:（1）研究区内各县、市HII在空间分布上,由北向南呈先下降、后升高、再下降的趋势,1990年、2000年、2010年和2020年研究区的HII为0.2800、0.3620、0.1804、0.2917;（2）人工建筑的扩张和滩涂围垦是影响HII高值区空间分布的关键驱动因素;（3）相关性分析结果表明,研究区内的斑块经历了集聚到破碎化再到集聚的过程,且HII具有一定的生态意义。本研究结果可为江苏省海岸带地区人类活动的调控和生态系统管理提供更多的空间信息和理论指导,也为计算大尺度空间的HII提供了思路。     

Integrating purifiers in refinery hydrogen networks: a retrofit case study

Hydrogen is an important utility in the production of clean fuels such as low-sulfur gasoline and diesel. The shortage of hydrogen resource motivates the integrated management of hydrogen networks with purifiers. In this paper, we propose a systematic approach for the retrofit design of these hydrogen networks. By establishing a state-space superstructure, all possible placements of existing compressors and purifiers are incorporated in the proposed MINLP model. Total annual cost (TAC) is employed as the optimizing object to understand the trade-offs between operating cost and capital cost. A real refinery system near Shanghai of China city is used to illustrate the applicability of the approach.     

中国石化安全信息管理平台的设计与开发

阐述了中国石化安全信息管理平台的设计思想和主要功能,通过实施中国石化内部网运行的安全信息管理系统,为中国石化安全管理信息化提供了应用平台.     

Could biochar amendment be a tool to improve soil availability and plant uptake of phosphorus? A meta-analysis of published experiments

Environmental Science and Pollution Research - As one of the most important nutrients for plant growth, phosphorus was often poorly available in soil. While biochar addition induced improvement of...     

危机管理体制构建与政府职能转变--后非典时期对于突发公共灾害处置的思考

本文以公共卫生危机和社会突发事件为个案,以政府面对这些危机所面临的挑战和取得的经验为研究对象,分析公共危机产生的原因和基本特征,提出了面对公共危机时应建立政府危机管理的预警系统,建立快速反应机制,动员社会参与危机救治,加强信息流通,加强公共危机的法制化建设.     

我国东部矿区生态系统退化机理初探

煤炭开采已经给矿区生态系统带来了极大的危害，使矿区生态系统的生产力不断下降，矿区生态系统正在发生退化。华东地区是我国的主要煤炭产区，该地区为高潜水位区域，因此该地区的生态退化具有其独特性，地表塌陷引起的土壤盐渍化、地面积水、水土流失等是引起这一地区生态系统退化的主要原因。