Characterization of plutonium in deep-sea sediments of the Sulu and South China Seas

Anthropogenic Pu isotopes are important geochemical tracers for sediment studies. Their distributions and sources in the water columns as well as the sediments of the North Pacific have been intensively studied; however, information about Pu in the Southeast Asian seas is limited. To study the isotopic composition of Pu, and thus to identify its sources, we collected sediment core samples in the South China Sea and the Sulu Sea during the KH-96-5 Cruise of the R/V Hakuho Maru. We analysed the activities of ^239+240Pu and the atom ratios of ²⁴⁰Pu/²³⁹Pu using isotope dilution sector-field inductively coupled plasma mass spectrometry (SF-ICP-MS). The ²⁴⁰Pu/²³⁹Pu atom ratios in the sediments of both areas (inventory weighted mean: 0.251 for the South China Sea and 0.280 for the Sulu Sea) were higher than the global fallout value (0.178 ± 0.019), suggesting the existence of Pu from the Pacific Proving Grounds in the North Pacific. Low inventories of ^239+240Pu in sediments were observed in the South China Sea (3.75 Bq/m²) and the Sulu Sea (1.38 Bq/m²). Most of the Pu input is still present in the water column. Scavenging and benthic mixing processes were considered to be the main processes controlling the distribution of Pu in the deep-sea sediments of both study areas.     

气候变化对江苏省城市系统用电量变化趋势的影响

江苏省是长江流域经济发展领先的地区,在其社会经济快速发展、人民生活水平迅速提高和电力供应有限的情况下,气候变化加剧了电力需求的紧张局面。根据江苏省50年来的用电量资料和1985年以来夏季平均温度距平资料,分析了城市系统用电量在随社会经济发展增长的同时,因气候异常特别是因夏季高温波动而引起的居民和城市系统用电量的变化。结果发现,夏季高温异常是居民和城市系统用电量增加的重要气候因子,指出未来气候变暖可能导致电力需求更加严峻的形势。对于现阶段长江流域各地区电力工业和国民经济的可持续发展具有科学意义和参考价值。     

Floating Population Increase and Its Influence on the Urban Population Situation:A Case Study in Beijing

1 BACKGROUND OF FLOATING POPULATIONIN CHINAChina's urbanization process was influenced mainly bythe government interventions before the adoption of thesocial and economic reform started in 1978. Since thefoundation of the People's Republic of China, thegovernment had strictly controlled the internal migration,especially from rural to urban areas. The ability of thegovernment to make a strong impact on the migrationand urbanization was realized by the household registrationsyste…     

不同经济发展阶段区域经济发展差异比较

在介绍区域经济发展阶段各种理论及划分方法的基础上,通过计算1985-2004年间,广西崇左市、安徽滁州市、江苏南通市经济发展的变化轨迹,确定不同区域经济发展阶段.利用偏离-份额分析法对区域经济发展水平进行研究,表明崇左市经济结构较差,结构对于经济增长的贡献小且竞争能力较弱;滁州市经济中增长快的产业部门比重较大,总体经济结构较好,结构对于经济增长具有一定贡献,竞争能力较强;南通市经济中朝阳的、增长快的产业部门比重大,总体经济结构好,结构对于经济增长的贡献大,且各产业部门总的增长势头大,具有很强的竞争能力.建议:①崇左市参与中国-东盟自由贸易区、中越"两廊一圈"经济带以及泛珠三角经济区域,吸收泛珠三角经济区的产业转移,加快发展国际贸易.②滁州市应融入南京都市圈,吸引和承接东部地区的产业转移,注意生态城市建设,发展循环经济,实现经济和生态环境的综合协调发展.③南通市应把资源节约型的增长模式和消费方式作为经济增长方式转变的核心,提升产业的综合竞争力,最终实现经济社会协调发展.     

Environmental impact and human exposure to PCBs in Guiyu, an electronic waste recycling site in China

PCB levels in fish (collected from local rivers), atmosphere and human milk samples have been studied to determine the exposure levels of PCBs for local residents and e-waste workers in Guiyu, a major electronic waste scrapping center in China. The source appointment and correlation analyses showed that homologue composition of PCBs in 7 species of fish were consistent and similar to commercial PCBs Aroclor 1248. PCB levels in air surrounding the open burning site were significantly higher than those in residential area. Inhalation exposure contributed 27% and 93% to the total body loadings (the sum of dietary and inhalation exposure) of the local residents, and e-waste workers engaged in open burning respectively. Total PCB concentrations in human milk ranged from N.D. to 57.6 ng/g lipid, with an average of 9.50 ng/g lipid. The present results indicated that commercial PCBs derived from e-waste recycling are major sources of PCBs accumulating in different environmental media, leading to the accumulation of high chlorinated biphenyls in human beings.     

Direct degradation of methylene blue by unactivated peroxymonosulfate: reaction parameters,kinetics, and mechanism

Environmental Science and Pollution Research - Advanced oxidation processes (AOPs) are efficient methods for water purification. However, there are few studies on using peroxymonosulfate (PMS) to...     

Short-term effects and economic burden assessment of ambient air pollution on hospitalizations for schizophrenia

Environmental Science and Pollution Research - The evidence on the health and economic impacts of air pollution with schizophrenia is scarce, especially in developing countries. In this...     

Numerical simulation and experimental research of fractal suspended carrier based on nonlinear equation

Environmental Science and Pollution Research - The geometric structure of the suspended carrier is an important factor that directly affects the effluent quality of the moving bed biofilm reactor,...     

Fractional diffusion model for emission and adsorption prediction of TXIB from wallpaper

Environmental Science and Pollution Research - Mercury injection test shows that wallpaper is a porous building material with a complex fractal mass transfer channel. Therefore, fractional...     

Comprehensive evaluation of land reclamation schemes in mining areas based on linguistic intuitionistic fuzzy group decision-making

Schemes to protect the geological environment and reclaim land are core requirements for an application for mining rights and complying with mining regulations. Mining enterprises must be supervised to ensure they fulfill their obligations. To guide oversight of such schemes and to provide references for their compilation and review, this study evaluates land reclamation schemes in mining areas using a multi-attribute group decision-making method. First, linguistic intuitionistic fuzzy numbers are used to describe the evaluation information. Considering the authority and preferences of experts, methods for determining expert weights in four cases are established. Max–min deviation then determines the attribute weights, and a method for linguistic intuitionistic fuzzy group decision-making is proposed. Finally, the practicability of this method is verified through a comparative analysis of land reclamation schemes for four mining areas in Sichuan Province, China. The results show the proposed method to give simple and effective evaluation, making it reasonably applicable to the compilation and review of land reclamation schemes.