全文获取类型
收费全文 | 15734篇 |
免费 | 1000篇 |
国内免费 | 3054篇 |
专业分类
安全科学 | 936篇 |
废物处理 | 272篇 |
环保管理 | 4619篇 |
综合类 | 8630篇 |
基础理论 | 1553篇 |
环境理论 | 1篇 |
污染及防治 | 1122篇 |
评价与监测 | 1215篇 |
社会与环境 | 1215篇 |
灾害及防治 | 225篇 |
出版年
2024年 | 39篇 |
2023年 | 185篇 |
2022年 | 322篇 |
2021年 | 349篇 |
2020年 | 435篇 |
2019年 | 352篇 |
2018年 | 331篇 |
2017年 | 508篇 |
2016年 | 627篇 |
2015年 | 696篇 |
2014年 | 699篇 |
2013年 | 1025篇 |
2012年 | 1081篇 |
2011年 | 1181篇 |
2010年 | 838篇 |
2009年 | 846篇 |
2008年 | 661篇 |
2007年 | 1084篇 |
2006年 | 1021篇 |
2005年 | 846篇 |
2004年 | 744篇 |
2003年 | 758篇 |
2002年 | 647篇 |
2001年 | 507篇 |
2000年 | 538篇 |
1999年 | 472篇 |
1998年 | 332篇 |
1997年 | 298篇 |
1996年 | 270篇 |
1995年 | 245篇 |
1994年 | 214篇 |
1993年 | 202篇 |
1992年 | 158篇 |
1991年 | 126篇 |
1990年 | 94篇 |
1989年 | 85篇 |
1988年 | 81篇 |
1987年 | 72篇 |
1986年 | 48篇 |
1984年 | 51篇 |
1983年 | 59篇 |
1982年 | 60篇 |
1981年 | 72篇 |
1980年 | 80篇 |
1979年 | 73篇 |
1978年 | 51篇 |
1977年 | 46篇 |
1973年 | 44篇 |
1972年 | 39篇 |
1971年 | 59篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
101.
102.
103.
104.
测定电镀废水中铬(Ⅵ)的新光度法 总被引:3,自引:0,他引:3
在硝酸介质中,二甲基黄先显色而后在加热条件下褪色,铬( )能显著阻抑此褪色反应,且阻抑程度与铬( )含量相关,据此建立了测定痕量铬( )的新方法。方法检出限是1.55×10-10g/ml,线性范围0.1~1.2μg/10ml,用于电镀废水中铬( )的测定,结果满意。 相似文献
105.
A ten year summary of concurrent ambient water column and sediment toxicity tests in the Chesapeake Bay watershed: 1990-1999 总被引:1,自引:0,他引:1
The goal of this study was to identify the relative toxicity ofambient areas in the Chesapeake Bay watershed by using a suiteof concurrent water column and sediment toxicity tests at seventy-five ambient stations in 20 Chesapeake Bay rivers from1990 through 1999. Spatial and temporal variability was examinedat selected locations throughout the 10 yr study. Inorganicand organic contaminants were evaluated in ambient water andsediment concurrently with water column and sediment tests toassess possible causes of toxicity although absolute causalitycan not be established. Multivariate statistical analysis wasused to develop a multiple endpoint toxicity index (TOX-INDEX) at each station for both water column and sediment toxicity data. Water column tests from the 10 yr testing period showed that49% of the time, some degree of toxicity was reported. The mosttoxic sites based on water column results were located inurbanized areas such as the Anacostia River, Elizabeth River andthe Middle River. Water quality criteria for copper, lead,mercury, nickel and zinc were exceeded at one or more of thesesites. Water column toxicity was also reported in localizedareas of the South and Chester Rivers. Both spatial and temporalvariability was reported from the suite of water column toxicitytests. Some degree of sediment toxicity was reported from 62% of the tests conducted during the ten year period. The ElizabethRiver and Baltimore Harbor stations were reported as the most toxic areas based on sediment results.Sediment toxicity guidelines were exceeded for one or more of thefollowing metals at these two locations: arsenic, cadmium,chromium, copper, lead, nickel and zinc. At the Elizabeth Riverstations nine of sixteen semi-volatile organics and two of sevenpesticides measured exceeded the ER-M values in 1990. Ambientsediment toxicity tests in the Elizabeth River in 1996 showedreduced toxicity. Various semi-volatile organics exceeded the ER-M values at a number of Baltimore Harbor sites; pyrene anddibenzo(a,h)anthracene were particularly high at one of thestations (Northwest Harbor). Localized sediment toxicity was alsoreported in the Chester, James, Magothy, Rappahannock, andPotomac Rivers but the link with contaminants was not determined.Both spatial and temporal variability was less for sedimenttoxicity data when compared with water column toxicity data. Acomparison of water column and sediment toxicity data for thevarious stations over the 10 yr study showed that approximatelyhalf the time agreement occurred (either both suite of testsshowed toxicity or neither suite of tests showed toxicity). 相似文献
106.
水中呋喃丹气相色谱-质谱的测定方法研究 总被引:1,自引:0,他引:1
建立了气相色谱-质谱联用法测定水中呋喃丹的方法。用二氯甲烷萃取酸性水样中的呋喃丹,浓缩后加入内标苊-d10,采用气-质联用仪中选择离子检测(SIM)模式进行监测,提取目标化合物的特征离子进行定量,该方法灵敏度高,水中呋喃丹的最低检测浓度可达0.05μg/L;准确度好,样品添加回收率在100.5%-111.0%之间;平行5次进行精密度试验,相对标准偏差低于6.21%。结果表明,方法简便、快速、准确、重现性好,适合各种水中呋喃丹的测定。 相似文献
107.
王瑞慧 《环境监测管理与技术》2007,19(3):56-57
分析了COD在线分析仪和实验室比对结果人为差异的原因是样品不均匀,在线分析仪取样装置滤过,取样层面和采样方式以及沉淀消除的方法不同造成的.提出应在相同的地点、层面和同一容器取样,用相同沉淀消除方法去除样品中氯离子干扰,保证两方法比对中使用水样的一致均匀,使测试结果正确可信. 相似文献
108.
地下土壤、水中DNAPLs污染的修复技术研究进展 总被引:1,自引:1,他引:1
综述了国内外地下土壤、含水层DNAPLs污染的迁移机理及其修复技术研究进展,对该领域的研究前景做了展望. 相似文献
109.
Kimpo metropolitan landfill has received various kinds of wastessince January 1992. The leachate level was measured to be 10.3 m in May 1995 and the level increased to 12.2 m in August 1996. Therefore, to prove the reason for the increasing leachate level, we calibrated hydraulic conductivity of each waste andintermediate layer using the HELP (Hydrologic Evaluation ofLandfill Performance) model. The leachate generation data measured from February 1993 to October 1995 was used in the model calibration. As a result of a model calibration, we obtained anaverage infiltration ratio and used this in analysis of the total water balance to predict elevation of leachate level. Main causes of the elevation of the leachate level were the high water content of the waste and the degradation of the leachate-drainage system caused by the subsidence of a naturalbarrier layer. 相似文献
110.
Patil MP Subramani T Patil SA Chakrabarti T 《Environmental monitoring and assessment》2002,76(3):299-309
A comprehensive environmental assessment (EA) is a pre-requisite before the site for developing a hazardous waste treatment and disposal facility (HWTDF) is selected. However, the resource limitations, especially for developing countries, often dictatethat the detailed EA be restricted to those sites, which are constraint free and have low hazard potentials. Thus, a preliminary screening exercise for assessing the suitability ofsite for developing the HWTDF needs to be carried out to avoid huge costs involved in detailed EA. While screening a HWTDF site,various factors such as present land use, ecologically sensitiveareas, geology and hydrogeology of the area, the quality and quantity of wastes, engineered safeguards, and the operationalprocedures that need to be adopted, are required to be addressed. In this paper, a multi-level screening criteria employing RemoteSensing, Constraint Mapping, Groundwater Pollution Potential Index (DRASTIC Index), and the Site Ranking was used to assess the suitability of a proposed site for the development of HWTDF.The study helped to identify various constraints at the proposedsite and their significance on the development of the HWTDF. 相似文献