全文获取类型
收费全文 | 4594篇 |
免费 | 74篇 |
国内免费 | 78篇 |
专业分类
安全科学 | 162篇 |
废物处理 | 195篇 |
环保管理 | 990篇 |
综合类 | 510篇 |
基础理论 | 1133篇 |
环境理论 | 2篇 |
污染及防治 | 1200篇 |
评价与监测 | 317篇 |
社会与环境 | 212篇 |
灾害及防治 | 25篇 |
出版年
2023年 | 30篇 |
2022年 | 70篇 |
2021年 | 35篇 |
2020年 | 37篇 |
2019年 | 43篇 |
2018年 | 94篇 |
2017年 | 72篇 |
2016年 | 85篇 |
2015年 | 97篇 |
2014年 | 96篇 |
2013年 | 635篇 |
2012年 | 123篇 |
2011年 | 171篇 |
2010年 | 174篇 |
2009年 | 153篇 |
2008年 | 186篇 |
2007年 | 175篇 |
2006年 | 175篇 |
2005年 | 148篇 |
2004年 | 149篇 |
2003年 | 162篇 |
2002年 | 138篇 |
2001年 | 138篇 |
2000年 | 99篇 |
1999年 | 65篇 |
1998年 | 72篇 |
1997年 | 48篇 |
1996年 | 55篇 |
1995年 | 74篇 |
1994年 | 54篇 |
1993年 | 54篇 |
1992年 | 57篇 |
1991年 | 44篇 |
1990年 | 51篇 |
1989年 | 48篇 |
1988年 | 56篇 |
1987年 | 41篇 |
1986年 | 39篇 |
1985年 | 45篇 |
1984年 | 75篇 |
1983年 | 54篇 |
1982年 | 53篇 |
1981年 | 57篇 |
1980年 | 42篇 |
1979年 | 62篇 |
1978年 | 48篇 |
1977年 | 34篇 |
1976年 | 27篇 |
1974年 | 25篇 |
1972年 | 24篇 |
排序方式: 共有4746条查询结果,搜索用时 622 毫秒
1.
Mughal Nafessa Kashif Maryam Arif Asma Guerrero John William Grimaldo Nabua Wilson C. Niedbała Gniewko 《Environmental science and pollution research international》2021,28(46):65116-65126
Environmental Science and Pollution Research - This study aims to re-examine the impacts of monetary and fiscal policy on environmental quality in ASEAN countries from 1990 to 2019. We utilized the... 相似文献
2.
Simas Angélica Mores Rúbia Steffens Juliana Dallago Rogério Marcos Kunz Airton Michelon William Fongaro Gislaine Viancelli Aline 《Environmental Chemistry Letters》2019,17(1):495-499
Environmental Chemistry Letters - Swine production generates large volumes of wastewater, rich in organic matter, nutrients and pathogens. Electrodisinfection is used to remove organic matter and... 相似文献
3.
4.
5.
6.
Danny Reible David Lampert David Constant Robert D. Mutch Jr. Yuewei Zhu 《补救:环境净化治理成本、技术与工艺杂志》2006,17(1):39-53
An active capping demonstration project in Washington, D.C., is testing the ability to place sequestering agents on contaminated sediments using conventional equipment and evaluating their subsequent effectiveness relative to conventional passive sand sediment caps. Selected active capping materials include: (1) AquaBlokTM, a clay material for permeability control; (2) apatite, a phosphate mineral for metals control; (3) coke, an organic sequestration agent; and (4) sand material for a control cap. All of the materials, except coke, were placed in 8,000‐ft test plots by a conventional clamshell method during March and April 2004. Coke was placed as a 1.25‐cm layer in a laminated mat due to concerns related to settling of the material. Postcap sampling and analysis were conducted during the first, sixth, and eighteenth months after placement. Although postcap sampling is expected to continue for at least an additional 24 months, this article summarizes the results of the demonstration project and postcap sampling efforts up to 18 months. Conventional clamshell placement was found to be effective for placing relatively thin (six‐inch) layers of active material. The viability of placing high‐value or difficult‐to‐place material in a controlled manner was successfully demonstrated with the laminated mat. Postcap monitoring indicates that all cap materials effectively isolated contaminants, but it is not yet possible to differentiate between conventional sand and active cap layer performance. Monitoring of the permeability control layer indicated effective reductions in groundwater seepage rates through the cap, but also showed the potential for gas accumulation and irregular release. All of the cap materials show deposition of new contaminated sediment onto the surface of the caps, illustrating the importance of source control in maintaining sediment quality. © 2006 Wiley Periodicals, Inc. 相似文献
7.
8.
Ronald Fuge Ian M. S. Laidlaw William T. Perkins Kerry P. Rogers 《Environmental geochemistry and health》1991,13(2):70-75
The many abandoned base metal mines of the mid-Wales ore field are sources of extensive pollution. Some of the mineralised veins contain large amounts of pyrite and marcasite and oxidative weathering of these produces sulphuric acid resulting in very acidic mine drainage waters. In addition, the spoil tips associated with these mines can contain abundant iron sulphides. Drainage waters from these sources have pH values as low as 2.6 and are heavily contaminated with metals such as Al, Zn, Cd and Ni.Two of the main rivers of the area, the Rheidol and Ystwyth, intercept heavily contaminated acidic drainage which has a marked effect on water quality. The Rheidol contains over 100 g L–1 Zn for 16 km downstream of the acid water influx. This level is over three times the recommended EEC limit for Zn in salmonoid waters of low hardness. 相似文献
9.
Analysis of pollutant levels in central Hong Kong applying neural network method with particle swarm optimization 总被引:6,自引:0,他引:6
Air pollution has emerged as an imminent issue in modernsociety. Prediction of pollutant levels is an importantresearch topic in atmospheric environment today. For fulfillingsuch prediction, the use of neural network (NN), and inparticular the multi-layer perceptrons, has presented to be acost-effective technique superior to traditional statisticalmethods. But their training, usually with back-propagation (BP)algorithm or other gradient algorithms, is often with certaindrawbacks, such as: 1) very slow convergence, and 2) easilygetting stuck in a local minimum. In this paper, a newlydeveloped method, particle swarm optimization (PSO) model, isadopted to train perceptrons, to predict pollutant levels, andas a result, a PSO-based neural network approach is presented. The approach is demonstrated to be feasible and effective bypredicting some real air-quality problems. 相似文献
10.
J. Christian Franson William L. Hohman Joseph L. Moore Milton R. Smith 《Environmental monitoring and assessment》1996,43(2):181-188
We used 363 blood samples collected from wild canvasback dueks (Aythya valisineria) at Catahoula Lake, Louisiana, U.S.A. to evaluate the effect of sample storage time on the efficacy of erythrocytic protoporphyrin as an indicator of lead exposure. The protoporphyrin concentration of each sample was determined by hematofluorometry within 5 min of blood collection and after refrigeration at 4 °C for 24 and 48 h. All samples were analyzed for lead by atomic absorption spectrophotometry. Based on a blood lead concentration of 0.2 ppm wet weight as positive evidence for lead exposure, the protoporphyrin technique resulted in overall error rates of 29%, 20%, and 19% and false negative error rates of 47%, 29% and 25% when hematofluorometric determinations were made on blood at 5 min, 24 h, and 48 h, respectively. False positive error rates were less than 10% for all three measurement times. The accuracy of the 24-h erythrocytic protoporphyrin classification of blood samples as positive or negative for lead exposure was significantly greater than the 5-min classification, but no improvement in accuracy was gained when samples were tested at 48 h. The false negative errors were probably due, at least in part, to the lag time between lead exposure and the increase of blood protoporphyrin concentrations. False negatives resulted in an underestimation of the true number of canvasbacks exposed to lead, indicating that hematofluorometry provides a conservative estimate of lead exposure.The U.S. Government's right to retain a non-exclusive, royalty-free licence in and to any copyright is acknowledgedDeceased 相似文献