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421.
提出了一个具有全新运转方式的新型RBC系统-回转升降生物接触工艺。通过清水充氧实验考查了实验装置的充氧能力;通过正交试验,确定了最佳运行条件;在最佳运行条件下,研究了本工艺处理有机废水的性能和效果。  相似文献   
422.
The characteristics of Aerosol Optical Depth (AOD) and Angstrom exponent were analyzed and compared using Cimel sunphotometer data from 2007 to 2008 at five sites located in the Yangtze River Delta region of China. The simultaneous measurements between Lin’an and ZFU showed a very high consistency of AOD at all wavelengths. The differences are less than 0.02 for Angstrom exponent and AOD at all wavelengths. The mean values of AOD at 440 nm at the Pudong, Taihu and Lin’an were about 0.74 ± 0.43, 0.85 ± 0.46, and 0.89 ± 0.46, respectively. The mean values of Angstrom exponents were about 1.27 ± 0.30, 1.20 ± 0.28 and 1.32 ± 0.35, respectively. The variation of monthly averaged AOD over Pudong showed a single peak distribution, with the maximum value occurring in July (AOD440nm 1.26 ± 0.61) and minimum in January (AOD440nm 0.50 ± 0.27). However, the variations of monthly averaged AOD at Taihu and Lin’an showed a bi-modal distribution. There were peak values of AOD occurring in July (AOD440nm 1.41 ± 0.49) and September (AOD440nm 1.22 ± 0.52) for Taihu. For Lin’an, the two peak values of AOD occurred in June (AOD440nm 1.17 ± 0.69) and September (AOD440nm 1.28 ± 0.46). The AOD accumulated mainly between 0.30–0.90(68%), 0.30–1.20(75%) and 0.30–1.20 (~75%) at Pudong, Taihu, and Lin’an, respectively. The Angstrom exponent accumulated mainly between 1.10–1.60 (75%), 1.10–1.50 (63%) and 1.20–1.60, 50% (50%) at Pudong, Taihu, and Lin’an, respectively.The synchronized observation showed that the AOD at Pudong was larger than those at Dongtan by 0.03, 0.03, 0.04, 0.07, and 0.08 at wavelengths of 1020 nm, 870 nm, 670 nm, 500 nm and 440 nm, respectively. The synchronized observations at Pudong, Taihu and Lin’an showed that the three stations had high level AOD with means at 440 nm about 0.68, 0.73, and 0.78, respectively. The relationship between MODIS retrieved and ground-based measured AOD shows good agreement with R2 ranging from 0.68 to 0.79 at Pudong, Taihu, Lin’an and Dongtan. The MODIS results were overestimated comparing the ground measurements at Pudong, Taihu, and Dongtan but exceptional at Lin’an.The analysis results between aerosol optical properties and wind measurement at Pudong showed that the wind speed from the east correlates with the lower observed AOD. The back trajectory analysis indicates that more than 50% airmasses were from the marine area at Pudong, while back trajectories distribution is relatively homogeneous at Lin’an.  相似文献   
423.
Industrial parks play a significant role in the production and use of goods and services. The proper management of solid waste is a major challenge for industrial parks due to the large quantity of wastes and the variability of waste characteristics from these types of developments. Therefore, integrated solid waste management has become very crucial to the industrial park managers. Such an approach requires industrial park managers to assess the overall use of resources, and to seek waste reduction, reuse and recycling opportunities both at the individual company level and among different tenant companies. The adoption of this method can bring both economic and environmental benefits. This paper introduces the planning efforts of a real case in China. It first presents the basic information on Tianjin Economic Development Area (TEDA), and then introduces its current practices on solid waste management. The main focus of this paper is to describe how to plan an integrated solid waste management system at TEDA. Benefits and challenges are all identified and analyzed. The experiences and methods from this case study should be applied in other industrial parks so as to improve the overall eco-efficiency of the whole industrial park.  相似文献   
424.
The characteristics and sources of major hydrocarbons and halocarbons in the wintertime ambient air of urban center of Shanghai, a mega city of China, were investigated. Propane, toluene, ethyl acetate, and benzene were the most abundant hydrocarbons. The majority of species showed significant variability in mixing ratios with occasional episodic increases. The more common use of liquefied petroleum gas fuel for taxis and light motorcycles was believed to lead to high levels of ambient propane over the urban center of Shanghai. Correlating with toluene, dichloromethane, and 1,2-dichloroethane (1,2-DCE), abundant chloromethane (up to a daily mean of 1.61?±?0.99 ppbv and a maximum of 5.34 ppbv) was mainly associated with industrial emissions, although biomass burnings exist widely in east China. The Chinese New Year (CNY) holiday period with no industrial activity over China provides a platform for the study of industrial emissions over the urban atmosphere of Shanghai. The normal weekly cycles were characterized by higher and more variable mixing ratios during weekdays which dropped during weekends. Enhanced mixing ratios were observed in the fortnight before the CNY holidays due to increased industrial emissions as a result of overtime production to make up for the holiday losses. During the CNY holidays, lower level and less variable mixing ratios were observed. A benzene/toluene (B/T) ratio of 0.6?±?0.4 (mean?±?std.) for the morning rush hour samples was identified to be the characteristic ratio of vehicular emissions. However, a B/T ratio of 0.4?±?0.2 from vehicles and other sources was derived for the ambient air.  相似文献   
425.
Ambient air samples were collected at two different locations between 2011 and 2012 in Zhengzhou, China in order to assess the concentration level, health risks, as well as the sources of polycyclic aromatic hydrocarbons (PAHs) in particulate matter (PM2.5). The mean annual levels of PM2.5 observed at industry site and residential site were 172?±?121 and 160?±?72 μg m?3, respectively, which were about five times the annual value of proposed PM2.5 standard (35 μg m?3) in China. The PM2.5 in all daily samples (n?=?47) exceeds the proposed PM2.5 standard in China (75 μg m?3) at both industrial and residential sites. Seasonal variations of PM2.5 showed a clear trend of winter?>?autumn?>?spring?>?summer at both sites. The total concentrations of 16 PM2.5-associated PAHs ranged from 61?±?51 to 431?±?281 and 38?±?25 to 254?±?189 ng m?3, with mean value of 176?±?233 and 111?±?146 ng m?3 at industry and residential sites, respectively. The major species were fluoranthene, pyrene, chrysene, benzo[b]fluoranthene and benzo[k]fluoranthene, and the concentration levels of PAHs in PM2.5 were higher in winter than those of other seasons at both sites. The annual mean values of toxicity equivalency concentrations of ∑16PAHs in PM2.5 were 22.8 and 13.5 ng m?3 in industry and residential area, respectively. In this study, the risk level of adult citizens through inhalation exposure to PAHs was calculated. The average estimates of lifetime inhalation cancer risks were approximately 8.9?×?10?7 and 6.3?×?10?7 for industry and residential sites, respectively. The main sources of 16 PAHs from both diagnostic ratios and principle component analysis identified as vehicular emissions and coal combustion.  相似文献   
426.
氯代多环芳烃(chlorinated polycyclic aromatic hydrocarbons,Cl-PAHs)是一种多环芳烃的氯代衍生物,具有与二噁英相似的毒性效应,并且在各种环境介质中广泛存在。Cl-PAHs已成为一种新型有机污染物,对生态环境和人体健康造成潜在的威胁。本文从Cl-PAHs的来源、污染现状、毒性效应与人体健康风险评价等几个方面对国内外有关Cl-PAHs的研究现状和最新进展进行了系统综述。  相似文献   
427.
立足当前环境类高等职业教育人才培养中存在的突出问题,以"以人为本"、"需求导向"、"特色品牌"、"工学结合"为原则,提出了环境类高职院校应在构建人才培养"三个平台、四个模块"的基础上,突出实践能力培养,实施工学结合的人才培养模式。  相似文献   
428.
采用混凝—Fenton法深度处理维生素B12废水,考察各操作参数对COD和色度去除效果的影响。实验结果表明:当混凝pH 4.5、聚合硫酸铁加入量300 mg/L、氧化pH 4.0、H2O2加入量420 mg/L、FeSO4?7H2O加入量334 mg/L、Fenton反应时间3 h时,混凝—Fenton法对维生素B12废水的深度处理效果较好,总COD和总色度的去除率分别为62.1%和90.0%;与Fenton法相比,混凝—Fenton法COD和色度去除率的提高率分别为17.4%和13.8%,且药剂成本降低了21.6%。  相似文献   
429.
To understand the transport and fate of antibiotic resistance genes in wastewater treatment plants, 12 resistance genes (ten tetracycline resistance genes, two sulfonamides genes) and class 1 integron gene (intI1) were studied in five wastewater treatment plants with different treatment processes and different sewage sources. Among these resistance genes, sulfonamides genes (sul1 and sul2) were of the most prevalent genes with detection frequency of 100 %. The effluent water contained fewer types of resistance genes than the influent in most selected plants. The abundance of five quantified resistance genes (tetG, tetW, tetX, sul1, and intI1) decreased in effluent of plants treating domestic or industrial wastewater with anaerobic/aerobic or membrane bioreactor (MBR) technologies, but tetG, tetX, sul1, and intI1 increased along the treatment units of plants treating vitamin C production wastewater by anaerobic/aerobic technology. In plant treating cephalosporins production wastewater by UASB/aerobic process, the quantities of tetG, tetX, and sul1 first decreased in anaerobic effluent water but then increased in aerobic effluent water.  相似文献   
430.
在一种详细的表面反应机理中加入了包含贵金属催化剂与助催化剂的硫中毒基元反应,建立了新的三效催化转化器催化反应机理。利用该机理进行了稳态工况数值模拟,得到了各排气污染物起燃温度与转化效率随尾气中SO2浓度的变化情况。采用灰色关联分析了SO2浓度与各排气组分转化效率的关联度,结果表明,SO2浓度对C3H6与NOx转化效率影响最大。对三效催化转化器的催化剂活性设计具有重要的参考价值,并对其工况设计及优化提供了指导。  相似文献   
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