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   8825篇
  免费   393篇
  国内免费   3197篇
安全科学   581篇
废物处理   538篇
环保管理   656篇
综合类   4604篇
基础理论   1492篇
污染及防治   3461篇
评价与监测   366篇
社会与环境   364篇
灾害及防治   353篇
  2024年   17篇
  2023年   163篇
  2022年   454篇
  2021年   378篇
  2020年   290篇
  2019年   297篇
  2018年   306篇
  2017年   392篇
  2016年   474篇
  2015年   512篇
  2014年   648篇
  2013年   881篇
  2012年   727篇
  2011年   751篇
  2010年   581篇
  2009年   516篇
  2008年   631篇
  2007年   491篇
  2006年   487篇
  2005年   348篇
  2004年   271篇
  2003年   322篇
  2002年   302篇
  2001年   231篇
  2000年   273篇
  1999年   286篇
  1998年   229篇
  1997年   221篇
  1996年   191篇
  1995年   153篇
  1994年   117篇
  1993年   117篇
  1992年   106篇
  1991年   81篇
  1990年   34篇
  1989年   34篇
  1988年   25篇
  1987年   16篇
  1986年   14篇
  1985年   10篇
  1984年   6篇
  1983年   4篇
  1982年   9篇
  1981年   6篇
  1979年   2篇
  1976年   1篇
  1974年   2篇
  1973年   3篇
  1972年   2篇
  1970年   1篇
排序方式: 共有10000条查询结果,搜索用时 24 毫秒
581.
Pesticide handlers and pet owners who use products such as shampoos and dips and insecticide-impregnated collars to treat and control fleas on companion animals are exposed to a variety of active ingredients. Chlorpyrifos exposures of adults and children were measured using urine biomonitoring following use of over-the-counter products on dogs. Age and gender-specific measurements of urinary 3, 5, 6-trichloro-2-pyridinol (TCPy) revealed modest elevations of biomarker excretion following shampoo/dips. Smaller TCPy increments were measured following application of impregnated dog collars. The extent of indoor activity and potential pet contact were important determinants of urine biomarker level. Children without direct pet contact excreted more TCPy following collar application. Pet collars may be a source of indoor surface contamination and human exposure. Children excreted up to 4 times more TCPy than adults when urine volumes were adjusted using age-specific creatinine excretion levels. Although chlorpyrifos is no longer used in the United States in pet care products, results of this research provide perspective on the extent of human exposure from similar pet care products. These pilot studies demonstrated that pet care products such as insecticidal shampoos and dips and impregnated collars may expose family members to low levels of insecticide relative to toxic levels of concern.  相似文献   
582.
A monoclonal antibody-based competitive antibody-coated enzyme-linked immunosorbent assay (ELISA) was developed and optimized for determining chlorpyrifos residue in agricultural products. The IC(50) and IC(10) of this ELISA were 3.3 ng/mL and 0.1 ng/mL respectively. The average recoveries in six agricultural products were between 79.5% and 118.0%, with the intra-assay coefficient of variation being less than 8 %. The limit of detection for all tested products was 30 ng/g. To the best of our knowledge, this assay has the best specificity among all the published research on ELISAs for chlorpyrifos.  相似文献   
583.

Background and purpose  

More and more coal-fired power plants equipped with seawater flue gas desulfurization systems have been built in coastal areas. They release large amount of mercury (Hg)-containing waste seawater into the adjacent seas. However, very limited impact studies have been carried out. Our research targeted the distribution of Hg in the seawater, sediment, biota, and atmosphere, and its environmental transportation.  相似文献   
584.

Purpose  

Nonpoint sources (NPS) pollution has been an important cause for water quality impairment worldwide. To take the temporal variations of both NPS pollution and in-stream attenuation into consideration, an inverse modeling approach and the load duration curve (LDC) method were combined for variable nutrient total maximum daily load (TMDL) development.  相似文献   
585.
Coastal zones provide habitat cores and corridors that maintain the diversity of entire landscapes, and they can form the cornerstone elements of regional conservation strategies. Natural environmental driving factors and excessive anthropogenic activities play important roles in coastal wetland change. Many studies have used remote sensing images to map and assess coastal wetland change on local or regional scales. This paper aims to provide insight into coastal wetland change in the Yancheng National Nature Reserve (YNNR) using remote sensing technology and landscape metrics analysis. The results reveal that grass flat and reed areas have significantly decreased, whereas agriculture fields, aquaculture ponds and built-up areas have continuously increased from 1988 to 2006. The spatial pattern of the coastal landscape has become fragmented and heterogeneous under great pressure from rapid economic development and population growth. The wetland changes have important impacts on natural habitat of the red-crowned cranes. The results of this study provide basic information that is required for developing measures toward a sustainable management and conservation of the YNNR.  相似文献   
586.
587.
Chen C  Zhou Q  Liu S  Xiu Z 《Chemosphere》2011,82(8):1147-1154
Phytoremediation is a novel and promising approach for the treatment of pollutants. This study did explore the potential of Aster amellus Linn. to decolorize a sulfonated azo dye Remazol Red (RR), a mixture of dyes and a textile effluent. Induction in the activities of lignin peroxidase, tyrosinase, veratryl alcohol oxidase and riboflavin reductase was observed during RR decolorization, suggesting their involvement in the metabolism of RR. UV-Visible absorption spectrum, HPLC and FTIR analysis confirmed the degradation of RR. Four metabolites after the degradation of the dye were identified as 2-[(3-diazenylphenyl) sulfonyl] ethanesulfonate, 4-amino-5-hydroxynaphthalene-2,7-disulfonate, naphthalene-2-sulfonate and 3-(1,3,5-triazin-2-ylamino)benzenesulfonate by using GC/MS. Textile effluent and mixture of dyes showed 47% and 62% decrease respectively in American Dye Manufacturers Institute value. BOD of textile effluent and mixture of dyes were reduced by 75% and 48% respectively, COD of industrial effluent and mixture of dyes was reduced by 60% and 75% and TOC was reduced by 54% and 69% respectively after the treatment by A. amellus for 60 h; this indicated that the plant can be used for cleaning textile effluents. Toxicity study revealed the phytotransformation of RR into non-toxic products.  相似文献   
588.
探讨了竹炭粒径、加入量、溶液 pH、吸附时间、Cu2+初始质量浓度等因素对竹炭吸附 Cu2+效果的影响.实验结果表明:竹炭对废水中Cu2+有很好的吸附效果,当竹炭粒径小于0.15 mm、加入量为 16 g/L、溶液 pH 为 6.0、Cu2+初始质量浓度 25 mg/L、吸附时间为 1.5 h 时,竹炭对 Cu2+的去...  相似文献   
589.
建立了以 CaO 为沉淀剂去除废碱液中 SiO2回收 NaOH 的工艺,研究了各工艺因素对siO2去除效果的影响,实验结果表明,CaO 沉淀除去废碱液中 SiO2的最佳工艺条件为:CaO 与废碱液中 SiO2摩尔比 3.0,反应温度80~95℃,反应时间 40~60 min,搅拌转速 200 r/min.在此条件下,S...  相似文献   
590.
三苯类废气处理进展   总被引:1,自引:1,他引:0  
综述了近年来三苯类废气处理所采用的方法,如吸收法、吸附法、催化氧化法、生物法、光催化法和低温等离子体法等,对各种方法的处理机理、处理效果以及优缺点进行了概括和分析,并指出联用技术将是未来的发展方向.  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