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   11917篇
  免费   109篇
  国内免费   89篇
安全科学   337篇
废物处理   443篇
环保管理   1638篇
综合类   2134篇
基础理论   3136篇
环境理论   8篇
污染及防治   2975篇
评价与监测   735篇
社会与环境   624篇
灾害及防治   85篇
  2022年   103篇
  2021年   98篇
  2020年   80篇
  2019年   93篇
  2018年   165篇
  2017年   142篇
  2016年   222篇
  2015年   194篇
  2014年   269篇
  2013年   880篇
  2012年   357篇
  2011年   497篇
  2010年   411篇
  2009年   481篇
  2008年   523篇
  2007年   520篇
  2006年   455篇
  2005年   420篇
  2004年   356篇
  2003年   365篇
  2002年   351篇
  2001年   472篇
  2000年   346篇
  1999年   210篇
  1998年   131篇
  1997年   157篇
  1996年   163篇
  1995年   192篇
  1994年   192篇
  1993年   160篇
  1992年   132篇
  1991年   170篇
  1990年   163篇
  1989年   158篇
  1988年   115篇
  1987年   114篇
  1986年   118篇
  1985年   92篇
  1984年   108篇
  1983年   110篇
  1982年   118篇
  1981年   108篇
  1980年   96篇
  1979年   112篇
  1978年   73篇
  1977年   77篇
  1975年   76篇
  1973年   73篇
  1972年   66篇
  1967年   66篇
排序方式: 共有10000条查询结果,搜索用时 8 毫秒
711.
The neutral red retention assay has been proposed to determine the lysosomal membrane stability in immune cells. Nevertheless, this assay implies many examinations under a microscope at short time intervals and therefore the analysis of few samples. The present study proposes two more rapid, efficient, and sensitive sample analyses using flow cytometry method. Lysosomal presence and lysosomal membrane integrity (LMI) were evaluated on the three-spined stickleback, Gasterosteus aculeatus (L.), a well-described model fish species for aquatic ecotoxicology studies. After development of the two biomarkers, they were validated by ex vivo contamination with endosulfan and copper and by in situ sampling. These immunomarkers were clearly modulated by pollutants and their variations seemed to be correlated with leucocyte mortality. Thus, from a practical point of view, lysosomal presence and LMI may provide novel and efficient means of evaluating immune capacities and indicating the toxic effects of environmental pollution.  相似文献   
712.
Clinical diagnostic laboratories are producing next-generation sequencing-based test results that are becoming increasingly incorporated into patient care. Whole genome and exome sequencing on fetal material derived from amniocytes, chorionic villi, or products of conception is starting to be offered clinically in specialized centers, but it has not yet become routine practice. The technical, interpretation, and ethical challenges are greatest in the area of prenatal medicine because the fetus has a limited health history, and the physical examination is only indirectly available via prenatal sonography. Here, we provide an overview of these challenges and highlight the clinical utility, reporting, and counseling issues associated with prenatal DNA sequencing. Future considerations are also discussed. © 2017 John Wiley & Sons, Ltd.  相似文献   
713.
The adsorption equilibrium time and effects of pH and concentration of 14C-labeled paraquat (1,1??-dimethyl-4,4??-bipyridylium dichloride) in two types of Malaysian soil were investigated. The soils used in the study were clay loam and clay soils from rice fields. Equilibrium studies of paraquat in a soil and pesticide solution were conducted. Adsorption equilibrium time was achieved within 2 h for both soil types. The amount of 14C-labeled paraquat adsorbed onto glass surfaces increased with increasing shaking time and remained constant after 10 h. It was found that paraquat adsorbed by the two soils was very similar: 51.73 (clay loam) and 51.59 ?? g g???1 (clay) at 1 ?? g/ml. The adsorption of paraquat onto both types of soil was higher at high pH, and adsorption decreased with decreasing pH. At pH 11, the amounts of 14C-labeled paraquat adsorbed onto the clay loam and clay soil samples were 4.08 and 4.05 ?? g g???1, respectively, whereas at pH 2, the amounts adsorbed were 3.72 and 3.57 ?? g g???1, respectively. Results also suggested that paraquat sorption by soil is concentration dependent.  相似文献   
714.
715.
716.
717.
718.
719.
720.
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