全文获取类型
收费全文 | 1006篇 |
免费 | 55篇 |
国内免费 | 339篇 |
专业分类
安全科学 | 26篇 |
废物处理 | 14篇 |
环保管理 | 147篇 |
综合类 | 580篇 |
基础理论 | 242篇 |
污染及防治 | 235篇 |
评价与监测 | 108篇 |
社会与环境 | 44篇 |
灾害及防治 | 4篇 |
出版年
2024年 | 2篇 |
2023年 | 20篇 |
2022年 | 27篇 |
2021年 | 27篇 |
2020年 | 29篇 |
2019年 | 38篇 |
2018年 | 32篇 |
2017年 | 32篇 |
2016年 | 47篇 |
2015年 | 46篇 |
2014年 | 54篇 |
2013年 | 103篇 |
2012年 | 65篇 |
2011年 | 95篇 |
2010年 | 67篇 |
2009年 | 79篇 |
2008年 | 87篇 |
2007年 | 90篇 |
2006年 | 75篇 |
2005年 | 53篇 |
2004年 | 48篇 |
2003年 | 40篇 |
2002年 | 34篇 |
2001年 | 28篇 |
2000年 | 29篇 |
1999年 | 22篇 |
1998年 | 16篇 |
1997年 | 17篇 |
1996年 | 14篇 |
1995年 | 15篇 |
1994年 | 17篇 |
1993年 | 12篇 |
1992年 | 6篇 |
1991年 | 3篇 |
1990年 | 3篇 |
1989年 | 5篇 |
1988年 | 4篇 |
1987年 | 5篇 |
1986年 | 2篇 |
1985年 | 1篇 |
1984年 | 2篇 |
1983年 | 1篇 |
1981年 | 3篇 |
1978年 | 2篇 |
1977年 | 1篇 |
1974年 | 1篇 |
1973年 | 1篇 |
排序方式: 共有1400条查询结果,搜索用时 46 毫秒
921.
Sequential sampling is a method for monitoring benthic macroinvertebrates that can significantly reduce the number of samples required to reach a decision, and consequently, decrease the cost of benthic sampling in environmental impact assessments.Rather than depending on a fixed number of samples, this analysis cumulatively compares measured parameter values (for example, density, community diversity) from individual samples, with thresholds that are based on specified degrees of precision.In addition to reducing sample size, a monitoring program based on sequential sampling can provide clear-cut decisions as to whethera priori-defined changes in the measured parameter(s) have or have not occurred. As examples, sequential sampling programs have been developed to evaluate the impact of geothermal energy development on benthic macroinvertebrate diversity at The Geysers, California, and for monitoring the impact of crude oil contamination on chironomid midge [Cricotopus bicinctus (Meigen) andC. mackenziensis Oliver] population densities in the Trail River, Northwest Territories, Canada. 相似文献
922.
Udai P. Singh James E. Orban 《Journal of the American Water Resources Association》1987,23(5):879-888
ABSTRACT: The Biscayne Aquifer is the sole source of drinking water for approximately three million residents of southeast Florida. Nine hazardous waste sites on the EPA National Priority List overlie this aquifer. Extensive investigation of an 80 square-mile area in metropolitan Miami detected low to moderate levels of toxic contaminants in the ground water, with volatile organic chemicals the most prevalent. The Centers for Disease Control concluded that contamination of the aquifer within the study area poses a serious potential threat to public health. Recommendations for source control and cleanup have been partially carried out. The top few feet of soil at the Miami Drum site have been excavated and relocated; ground water encountered during excavation has been withdrawn and treated, and the Northwest 58th Street Landfill has been closed. Recovery and treatment of ground water from the contaminated area was the recommended cleanup measure and has been approved by EPA and state and local agencies. A preventive action program for the Biscayne Aquifer region was also recommended for implementation by local agencies. This program consists of regulations, waste management practices, construction and treatment guidelines, and public information activities and materials. Implementing this program will help keep the Biscayne Aquifer water drinkable far into the future. 相似文献
923.
924.
Mineral exploitation is a necessary component of China's economic development goals. Such exploitation brings with it the potential for serious environmental degradation. Careful environmental impact assessments of mining projects are required in order to implement China's environmental protection law and identify measures for protecting surrounding agricultural environments. This article describes an environmental information system that has been developed for the purpose of assisting with the environmental impact assessment of nonferrous mining operations with a particular focus on agricultural impacts. An application of the environmental information system to the Yongping copper mine, located in Jiangxi Province, is discussed. The role of the environmental information system is analyzing and predicting soil contamination from heavy metals and other types of impacts from this mining operation is described. The environmental information system is designed for implementation on an IBM PC/XT microcomputer. The experience gained from the Yongping copper mine application and the growing popularity of microcomputers in China indicate a significant potential for the effective use of a microcomputer-based environmental information system in other parts of China. 相似文献
925.
Scott N. Hamlin 《Journal of the American Water Resources Association》1989,25(2):255-262
ABSTRACT: Water samples for dissolved mercury require special treatment because of the high chemical mobility and volatility of this element. Widespread use of mercury and its compounds has provided many avenues for contamination of water. Two laboratory tests were done to determine the relative permeabilities of glass and plastic sample bottles to mercury vapor. Plastic containers were confirmed to be quite permeable to airborne mercury, glass containers were virtually impermeable. Methods of preservation include the use of various combinations of acids, oxidants, and complexing agents. The combination of nitric acid and potassium dichromate successfully preserved mercury in a large variety of concentrations and dissolved forms. Because this acid-oxidant preservative acts as a sink for airborne mercury and plastic containers are permeable to mercury vapor, glass bottles are preferred for sample collection. To maintain a healthy work environment and minimize the potential for contamination of water samples, mercury and its compounds are isolated from the atmosphere while in storage. Concurrently, a program to monitor environmental levels of mercury vapor in areas of potential contamination is needed to define the extent of mercury contamination and to assess the effectiveness of mercury clean-up procedures. 相似文献
926.
David F. Bradford Lynda A. Smith Deborah S. Drezner J. David Shoemaker 《Environmental management》1991,15(6):785-795
In much of the San Joaquin Valley, California, USA, inadequate drainage of applied irrigation water and accumulating salts
in the soil have necessitated the installation of subsurface tile drainage systems to preserve crop productivity. At present,
these subsurface drainage waters are disposed of by means of evaporation ponds or discharges into the San Joaquin River. Unfortunately,
most of these agricultural drainage waters contain high concentrations of salts and naturally occurring trace elements, such
as selenium, and recent evidence indicates that substantial numbers of waterbirds are exposed to contamination by selenium
in the evaporation ponds. In order to avoid, minimize, or mitigate the adverse impacts on wildlife using the ponds, alternative
pond management methods must be identified and evaluated for implementation. A number of methods have the potential to be
cost-effective in significantly reducing the contamination hazard to birds using agricultural evaporation ponds. Twenty general
methods were evaluated in this study, and four methods are recommended for implementation: remove levee vegetation, remove
windbreaks, deepen the ponds, and haze birds. A number of other methods are recommended for further consideration because
they appear to have good prospects for reducing the contamination hazard: steepen interior levee slopes, apply herbicides
and insecticides, place netting on pond shorelines, and provide freshwater habitat adjacent to evaporation ponds. It may be
necessary to use a combination of methods to effectively control selenium contamination of aquatic birds because it is unlikely
that a single affordable pond management method will be able to entirely eliminate the contamination hazard. 相似文献
927.
环境中五氯酚监测研究进展 总被引:4,自引:0,他引:4
本文概述了五氯酚(PCP)的环境污染、人群暴露水平及目前有关监测方法研究进展。环境污染主要来源于本品的生产及工农业中的应用。在我国主要广泛用于杀灭血吸虫的中间宿主——钉螺。人体通过污染的空气、水体及食品可摄入PCP造成生物蓄积,危害健康。监测方法有化学法、紫外分光光度法、色谱法、极谱法、电化学检测法等,其中,色谱法简单、灵敏,易于普及使用。 相似文献
928.
Carvalhaes GK Brooks P Marques CG Azevedo JA Machado MC Azevedo GC 《Chemosphere》2002,46(9-10):1413-1416
After an exhaustive investigation, in 1997 the source of the milk contamination in Germany was traced to citrus pulp pellets originating from Brazil. It has been shown that lime was the source of the PCDD/F contamination of these products. After this conclusion, a continuous monitoring program has been performed over a two year period and the results are presented in this paper. Standard isotope dilution techniques were used for all samples, which were analyzed by selected ion monitoring high resolution GC–MS. 相似文献
929.
Wilkins K Bøwadt S Larsen K Sporring S 《Environmental science and pollution research international》2002,9(3):166-168
Although PCB in caulking materials has been forbidden for many years in most of Europe, including Denmark, there has been continued interest to measure PCB levels in the air of contaminated buildings and blood of the occupants (Mengon and Schlatter 1993, Fromme et al. 1996, Ewers et al. 1998, Currado and Harrad 1998, Gabrio et al. 2000). The relatively low priority for investigations of this contamination is probably due to the small quantities inhaled compared to exposure via food, and the rapid metabolism of the most volatile congeners demonstrated by low concentrations of all congeners in the blood of exposed persons (Ewers et al. 1998, Gabrio et al. 2000). There is, however, evidence that PCB containing caulking materials have been used even during the '90s (Fromme et al. 1996). In Denmark, it is estimated that 75 t PCB is still in buildings (Organization of Sealant Branch's Manufacturers and Distributors 2000). During an investigation of dust from buildings with excessive microbial growth (including 35 rooms from 9 buildings), the analysis of semivolatile compounds by thermal desorption-GC/MS of samples from a single building surprisingly revealed large amounts of PCBs containing 3, 4 and 5 chlorine atoms, 10-20 times the amounts found in samples from other buildings. Extraction of the dust by SFE followed by GC/ECD analysis for 12 PCB congeners showed that there was approximately 20 times the total PCB concentrations in dust from the polluted building compared to the levels in the other buildings. Subsequent headspace analysis of caulking material from the polluted building revealed this to be the source. Shelf dust functions as a passive sampling medium and, thus, can be used as a screening method to detect PCB and other semivolatile pollution indoors. 相似文献
930.