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   744篇
  免费   7篇
  国内免费   7篇
安全科学   17篇
废物处理   32篇
环保管理   134篇
综合类   139篇
基础理论   155篇
环境理论   1篇
污染及防治   192篇
评价与监测   38篇
社会与环境   33篇
灾害及防治   17篇
  2024年   8篇
  2023年   10篇
  2022年   15篇
  2021年   27篇
  2020年   26篇
  2019年   20篇
  2018年   20篇
  2017年   25篇
  2016年   43篇
  2015年   24篇
  2014年   33篇
  2013年   77篇
  2012年   40篇
  2011年   44篇
  2010年   25篇
  2009年   29篇
  2008年   32篇
  2007年   32篇
  2006年   25篇
  2005年   17篇
  2004年   21篇
  2003年   30篇
  2002年   23篇
  2001年   12篇
  2000年   9篇
  1999年   4篇
  1998年   7篇
  1997年   2篇
  1996年   4篇
  1995年   7篇
  1994年   6篇
  1991年   4篇
  1990年   5篇
  1989年   4篇
  1988年   5篇
  1987年   2篇
  1986年   6篇
  1985年   6篇
  1982年   2篇
  1981年   2篇
  1980年   2篇
  1978年   4篇
  1976年   2篇
  1974年   3篇
  1973年   2篇
  1972年   2篇
  1968年   1篇
  1967年   1篇
  1966年   1篇
  1958年   1篇
排序方式: 共有758条查询结果,搜索用时 0 毫秒
111.
    
Direct synthesis of dimethyl ether(DME) by CO2 hydrogenation has been investigated over three hybrid catalysts prepared by different methods:co-precipitation,sol-gel,and solid grinding to produce mixed Cu,ZnO,ZrO2 catalysts that were physically mixed with a commercial ferrierite(FER) zeolite.The catalysts were characterized by N2 physisorption,X-ray diffraction(XRD),transmission electron microscopy(TEM),X-ray photoelectron spectroscopy(XPS),temperature programmed...  相似文献   
112.
113.
114.
115.
116.
Waste water treatment plant (WWTP) is considered as an important source of surface water contamination by enteric pathogens. In this study, we describe the occurrence of enteric viruses (group A rotaviruses, noroviruses, astroviruses, sapoviruses, hepatitis A virus, and hepatitis E virus) and Clostridium difficile in the effluent of a wastewater treatment plant during a 1-year period. Enteric viruses were simultaneously and efficiently concentrated in a single step using methacrylate monolithic chromatographic support. Rotaviruses, noroviruses (genogroup I and II), and sapoviruses were detected in all 12 concentrated samples, whereas astroviruses were not detected in August and September and hepatitis A and E viruses were not detected at all. Clostridium difficile was detected in all samples and altogether 121 strains were isolated and grouped into 32 different ribotypes of which 014/020 and 010 were most prevalent. Pathogens detected in WWTP effluent partially reflect the epidemiological situation of enteric viruses and C. difficile in human population and open the discussion on implementation of possible techniques for virus and bacteria removal from WWTP effluent prior to release into the surface water system.  相似文献   
117.
118.
119.
         下载免费PDF全文
Although pharmaceuticals have been detected in the environment only in the range from ng/L to g/L, it has been demonstrated that they can adversely affect the health status of aquatic organisms. Lysosomal membrane stability (LMS) has previously been applied as an indicator of cellular well-being to determine health status in bivalve mussels. The objective of this study is to evaluate LMS in Ruditapes philippinarum haemolymph using the neutral red retention assay (NRRA). Clams were exposed in laboratory conditions to caffeine (0.1, 5, 15, 50 μg/L), ibuprofen (0.1, 5, 10, 50 μg/L), carbamazepine and novobiocin (both at 0.1, 1, 10, 50 μg/L) for 35 days. Results show a dose-dependent effect of the pharmaceuticals. The neutral red retention time measured at the end of the bioassay was significantly reduced by 50% after exposure to environmental concentrations (p < 0.05) (caffeine = 15 μg/L; ibuprofen = 10 μg/L; carbamazepine = 1 μg/L and novobiocin = 1 μg/L), compared to controls. Clams exposed to these pharmaceuticals were considered to present a diminished health status (retention time < 45 min), significantly worse than controls (96 min) (p < 0.05). The predicted no environmental effect concentration (PNEC) results showed that these pharmaceuticals are very toxic at the environmental concentrations tested. Measurement of the alteration of LMS has been found to be a sensitive technique that enables evaluation of the health status of clams after exposure to pharmaceuticals under laboratory conditions, thus representing a robust Tier-1 screening biomarker.  相似文献   
120.
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