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61.
Ionic composition of submicron particles (PM1.0) during the long-lasting haze period in January 2013 in Wuhan, central China 总被引:1,自引:0,他引:1
Hairong Cheng Wei Gong Zuwu Wang Fan Zhang Xinming Wang Xiaopu Lv Jia Liu Xiaoxin Fu Gan Zhang 《环境科学学报(英文版)》2014,26(4):810-817
In January 2013, a long-lasting severe haze episode occurred in Northern and Central China; at its maximum, it covered a land area of approximately 1.4 million km2. In Wuhan, the largest city in Central China, this event was the most severe haze episode in the 21st century. Aerosol samples of submicron particles (PM1.0) were collected during the long-lasting haze episode at an urban site and a suburban site in Wuhan to investigate the ion characteristics of PM1.0 in this area. The mass concentrations of PM1.0 and its water-soluble inorganic ions (WSIIs) were almost at the same levels at two sites, which indicates that PM1.0 pollution occurs on a regional scale in Wuhan. WSIIs (Na+, NH4+, K+, Mg2+, Ca2+, Cl-, NO3- and SO42-) were the dominant chemical species and constituted up to 48.4% and 47.4% of PM1.0 at WD and TH, respectively. The concentrations of PM1.0 and WSIIs on haze days were approximately two times higher than on normal days. The ion balance calculations indicate that the particles were more acidic on haze days than on normal days. The results of the back trajectory analysis imply that the high concentrations of PM1.0 and its water-soluble inorganic ions may be caused by stagnant weather conditions in Wuhan. 相似文献
62.
当前,我国的建设项目环境监理仍处于起步阶段。环境监理管理体系尚不完备。对西藏自治区而言,建设项目环境监理工作在许多行业领域尚属空白,法律法规仍不健全。本文通过介绍国内环境监理的发展态势及各省建设项目环境监理试点工作的经验。结合西藏自治区生态环境特征,借鉴青藏铁路环境监理试点工程取得的宝贵经验,对西藏自治区环境监理工作的开展进行探讨,以期为相关部门制定决策提供参照,尽快摸索出一条适合西藏自治区的环境监理模式,逐步使建设项目环境监理制度化,并在西藏自治区范围内成功实施。 相似文献
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64.
以佛子岭地震台数字化仪器记录到的远震数据为基础,应用多道反褶积方法分组提取邻近地震事件的接收函数,并选择合适的地层厚度将台站下方介质结构简化成关于S波速度的水平分层模型。以此对Ps转换波的接收函数进行共转换点偏移叠加,反演计算得到每个水平层中的S波速度值,并给出了佛子岭台台基下方一维S波速度结构图。 相似文献
65.
66.
Hui Wang Chong-qing Wang Jian-gang Fu Guo-hua Gu 《Waste management (New York, N.Y.)》2014,34(2):309-315
The surface free energy, surface tension and contact angles were performed to investigate the properties of wetting agents. Adsorption of wetting agents changes wetting behavior of polymer resins. Flotability of polymer materials modulated by wetting agents was studied, and wetting agents change significantly flotability of polymer materials. The flotability decreases with increasing the concentration of wetting agents, and the wetting ability is lignin sulfonate (LS) > tannic acid (TA) > methylcellulose (MC) > triton X-100 (TX-100) (from strong to weak). There is significant difference in the flotability between polymer resins and plastics due to the presence of additives in the plastics. Flotation separation of two-component and multicomponent plastics was conducted based on the flotability modulated by wetting agents. The two-component mixtures can be efficiently separated using proper wetting agent through simple flotation flowsheet. The multicomponent plastic mixtures can be separated efficiently through multi-stage flotation using TA and LS as wetting agents, and the purity of separated component was above 94%, and the recovery was more than 93%. 相似文献
67.
Hui-zhen Fu Yuh-shan Ho Yu-mei Sui Zhen-shan Li 《Waste management (New York, N.Y.)》2010,30(12):2410-2417
This study is a bibliometric analysis of solid waste research to evaluate the current trends, using the literature in the Science Citation Index (SCI) database from 1993 to 2008. Analyzed aspects included document type, language, and publication output as well as distribution of journals, subject category, countries, institutes, title-words, author keywords, and ‘Keywords Plus’. An evaluating indicator, h-index, was applied to characterize the solid waste publications. The trend of publication outputs during 1993–2008 coincided with a power and an exponential model. Based on the exponential model during 2001–2008, the number of articles on solid waste in 2013 is predicted to be twice that in 2008. The most common subject category is environmental science and the most productive journal is Waste Management. The USA with most publications and China with the highest growth rate were compared. Finally, author keywords, words in title, and ‘Keywords Plus’ were analyzed to provide research emphasis. The results showed that mainstream research was centered on the following methods: recycling, landfilling, composting and waste-to-energy. Heavy metals, fly ash and sewage sludge were considered recent research hotspots. 相似文献
68.
镍的作物效应及临界值研究 总被引:11,自引:0,他引:11
在三种紫色土(酸性,中性,石灰性)上添加Ni(0,10,30,60,100,200mg/kg土)进行莴笋盆栽试验,结果表明:低浓度的Ni能刺激作物生长,而高浓度的Ni则阻碍作物生长,使叶片黄化。三种土因性质及本身肥力水平的差异,使酸性紫色土上作物Ni最敏感,石灰性紫色土上次之,中性紫色土上最不敏感,且Ni在作物体内分配规律也有所不同,比较了土壤全Ni,有效Ni,植株根Ni作为的临界值的优越性,结果 相似文献
69.
中国生态农业与绿色食品 总被引:8,自引:0,他引:8
本文从农业环境问题和食品安全性出发,阐述了中国生态农业的兴起及特点,绿色食品生产的要求,生态农业与绿色食品的关系。介绍了几种可用于开发绿色食品的优化生态模式。 相似文献
70.
对1224个工种(岗位)的工人接触生产性毒物、粉尘、高温的状况以及部分工种(岗位)的工人体力劳动强度状况进行了调研,初步了解到机械工业的主要职业危害因素、危害分布、危害程度和特征。 相似文献