首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   996篇
  免费   52篇
  国内免费   325篇
安全科学   45篇
废物处理   71篇
环保管理   62篇
综合类   554篇
基础理论   187篇
污染及防治   343篇
评价与监测   48篇
社会与环境   36篇
灾害及防治   27篇
  2023年   10篇
  2022年   57篇
  2021年   33篇
  2020年   23篇
  2019年   24篇
  2018年   28篇
  2017年   55篇
  2016年   45篇
  2015年   42篇
  2014年   76篇
  2013年   107篇
  2012年   97篇
  2011年   75篇
  2010年   56篇
  2009年   68篇
  2008年   87篇
  2007年   58篇
  2006年   72篇
  2005年   27篇
  2004年   24篇
  2003年   29篇
  2002年   29篇
  2001年   23篇
  2000年   25篇
  1999年   33篇
  1998年   26篇
  1997年   23篇
  1996年   18篇
  1995年   25篇
  1994年   11篇
  1993年   16篇
  1992年   18篇
  1991年   10篇
  1990年   6篇
  1989年   3篇
  1988年   5篇
  1987年   1篇
  1986年   1篇
  1985年   4篇
  1984年   1篇
  1983年   1篇
  1982年   1篇
排序方式: 共有1373条查询结果,搜索用时 656 毫秒
241.
结合内梅罗指数法的原理,考虑金属毒性的积累效应,引入污染因子权重值,将权重值最大的评价指标纳入计算,采用改进的内梅罗指数法评价城市河道的水质污染状况。并对水质的划分标准临界值进行计算,以此作为评价水质污染状况的依据。研究结果表明,两种方法具有明显的差异,改进的内梅罗指数法对水质污染状况的评价结果较传统内梅罗指数法的辨识度更高,能够综合客观全面地体现城市河道水质状况,与真实情况较好的吻合,更为客观、合理。  相似文献   
242.
研究了用Fenton试剂处理选矿废水中残余的黄药,分别考查了氧化时间、反应初始pH值、Fe2+浓度及H2O2用量对黄药降解效果的影响,用正交试验确定了4个因素的最好条件。结果表明:初始pH值和H2O2用量是影响去除效果的主要因素;氧化时间为60 m in,反应初始pH=4,[Fe2+]=20 mg/L,[H2O2]=20 mg/L,黄药的浓度为125 mg/L时,黄药的去除率达到99.5%;初步探讨了Fenton试剂净化废水中黄药的机理是.OH自由基先将黄药氧化为过氧化黄原酸盐,再将其氧化为CO2,黄药得到去除。  相似文献   
243.
铬渣的热解无害化处理   总被引:1,自引:0,他引:1  
采用热解工艺无害化处理铬渣,探讨了稻秆在铬渣无害化处理中的作用.研究了热解温度、稻秆与铬渣质量比、铬渣粒径及保温时间对铬渣热解无害化处理的影响,并分析了热解前后热解产物中铬元素形态的变化.结果表明,热解工艺能有效地将铬渣中Cr(Ⅵ)还原,稻秆热解过程中产生的气相挥发分对Cr(Ⅵ)的还原起核心作用.较为适宜的热解条件:热解温度为400 ℃,稻秆与铬渣质量比为0.10,铬渣粒径<2 000 μm,保温时间为10 min.在该热解条件处理下,热解产物中的Cr(Ⅵ)质量浓度为121 mg/kg,低于热解前铬渣中的Cr(Ⅵ)(3 400 mg/kg).热解后,可交换态及碳酸盐结合态铬含量降低,大部分铬转化成了稳定的有机结合态和残渣态,极大地降低了铬渣的危害.第一作者:张大磊,男,1982生,博士研究生,研究方向为固体废弃物热处理.  相似文献   
244.
Concentrations and tissue distribution of organochlorine pesticides (OCPs) in different tissues of freshwater fish, silver carp (Hypophthalmichthys molitrix) and bighead carp (Aristichthys nobilis), collected from Poyang Lake, China’s largest shallow lake, and were studied. OCPs were detected with the observed concentrations ranging from 280.67 to 1,006.58 ng/g wet weight (ww) for bighead carp and from 67.28 to 930.06 ng/g ww for silver carp. Composition analysis demonstrated OCPs in both fish were from the same polluted environment, and then, the species-specific bioaccumulation might be mainly due to the different fish age as well as the different feeding habits elucidating from the stable carbon (δ13C) and nitrogen (δ15N) isotope analysis. Tissue distribution indicated that dietary intake was the major exposure route of OCPs for both fish and higher accumulation potency of OCPs by the hepatobiliary-related tissues (such as liver, kidney, bile, and heart). The higher metabolic activities of these tissues elucidating from the higher values of δ15N might be the potential-determined factor responsible for the tissue-specific accumulation.  相似文献   
245.
城市模化垃圾焚烧烟气中二氧化硫的生态特性   总被引:4,自引:0,他引:4  
对模化广州市城市生活垃圾进行焚烧处理 ,从燃烧温度、炉内停留时间、过量空气系数以及垃圾尺寸等方面研究了 SO2 的生成特性和控制条件。  相似文献   
246.
阐述了在焦化行业开展清洁生产的必要性,结合焦化企业开展清洁生产的实例,从废物最小化和资源化等方面概述了清洁生产技术在焦化行业中的应用;并以山东焦化企业为例论述如何做好清洁生产工作。  相似文献   
247.
塑料和橡胶类废物的热物理与焚烧特性研究的进展   总被引:3,自引:0,他引:3  
随着社会和科技的发展,塑料和橡胶废弃量与日俱增,已成为城市垃圾的重要组成,由于这类废弃的聚合物给环境带来了污染问题,怎样合理地处理和利用已经成为一项重要的研究课题,本文对塑料和橡胶类的废物的理化性质,热值,焚烧特性,污染特性进行了论述,并根据它们的热物理及焚烧特性提出了进一步优化废物焚烧炉,完善低污染,低腐蚀,低粘结的废弃物的焚烧工艺的一些设想。  相似文献   
248.
链霉菌(Streptomyces sp.)对吡啶的降解特性   总被引:2,自引:0,他引:2  
从焦化废水的活性污泥中分离出对溶液中吡啶具有降解效果的链霉菌(Streptomyces sp.),考察了吡啶初始质量浓度、初始pH、降解温度、振荡速度等对吡啶降解效果的影响,初步探讨了该菌降解吡啶的动力学与机理。实验结果表明,该菌对吡啶有很强的耐受力,能以吡啶为惟一碳源和氮源生长。链霉菌在初始pH=8、降解温度30℃、振荡速度100r/min的条件下培养7d后,吡啶的质量浓度从250mg/L降至6.6mg/L,吡啶降解率达97.4%。该菌对吡啶的降解反应符合一级动力学方程,初始质量浓度为100mg/L时的吡啶降解速率常数为0.4011d^-1。紫外一可见光谱分析表明,吡啶经该菌降解后的特征环被破坏。  相似文献   
249.
With China's rapid economic development, environmental problems have become more and more serious. Particulate air pollution is terrible in cities with large and dense population. It may lead to adverse health effects and economic costs. In this study, we calculated the health effects of pollution caused by particulate matter with aerodynamic diameters less than 10mum (PM(10)) in 111 Chinese cities in 2004 according to statistical data and epidemiological exposure-response functions. Using economic burden of disease analysis, an economic assessment of these health risks was also presented. In contrast to many previous studies that have examined individual cities, this study covered most large and medium-sized cities in China, which accounted for more than 70% gross domestic product (GDP) of China in 2004. The total economic cost caused by PM(10) pollution was estimated as approximately US$ 29,178.7 million. Mega cities such as Beijing, Shanghai, and Tianjin contribute relatively more to the total costs. The results will help policy makers in formulating more effective countermeasures and increasing public awareness to enhance environmental protection.  相似文献   
250.
Municipal solid waste (MSW) landfills are one of the major sources of offensive odors potentially creating annoyance in adjacent communities. At the end of May 2007, an odor pollution incident occurred at the Tianziling landfill site, Hangzhou, China, where the residents lodged complaints about the intense odor from the landfill, which drew a significant attention from the government. In this study, ambient air monitoring was conducted at the Tianziling landfill site. The main odor composition of the gas samples collected on June 1st 2007 and the reduction of various odorous gases from the samples collected on June 1st 2009 due to the applied odor control techniques were determined using gas chromatography-mass spectrometry (GC-MS). In addition, variations of primary odorous gaseous (NH3 and H2S) concentrations at different locations in the landfill site from July 2007 to June 2009 were also investigated by using classical spectrophotometric methods. Results showed that a total of 68 volatile compounds were identified among which H2S (56.58-579.84 μg/m3) and NH3 (520-4460 μg/m3) were the notable odor components contributing to 4.47-10.92% and 83.91-93.94% of total concentrations, respectively. Similar spatial and temporal shifts of H2S and NH3 concentrations were observed and were significantly affected by environmental factors including temperature, air pressure and wind direction. Odor pollution was worse when high temperature, high humidity, low air pressure, and southeast, northeast or east wind appeared. Moreover, the environmental sampling points of the dumping area and the leachate treatment plant were found to be the main odor sources at the Tianziling landfill site. The odor control technologies used in this project had a good mitigating effect on the primary odorous compounds. This study provides long-term valuable information concerning the characteristics and control of odors at landfill sites in a long run.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号