全文获取类型
收费全文 | 555篇 |
免费 | 4篇 |
国内免费 | 15篇 |
专业分类
安全科学 | 27篇 |
废物处理 | 28篇 |
环保管理 | 104篇 |
综合类 | 63篇 |
基础理论 | 101篇 |
污染及防治 | 154篇 |
评价与监测 | 58篇 |
社会与环境 | 35篇 |
灾害及防治 | 4篇 |
出版年
2023年 | 11篇 |
2022年 | 22篇 |
2021年 | 18篇 |
2020年 | 5篇 |
2019年 | 3篇 |
2018年 | 19篇 |
2017年 | 16篇 |
2016年 | 21篇 |
2015年 | 13篇 |
2014年 | 25篇 |
2013年 | 58篇 |
2012年 | 14篇 |
2011年 | 28篇 |
2010年 | 26篇 |
2009年 | 20篇 |
2008年 | 24篇 |
2007年 | 24篇 |
2006年 | 22篇 |
2005年 | 13篇 |
2004年 | 17篇 |
2003年 | 18篇 |
2002年 | 17篇 |
2001年 | 8篇 |
2000年 | 5篇 |
1999年 | 4篇 |
1998年 | 9篇 |
1997年 | 10篇 |
1996年 | 9篇 |
1995年 | 3篇 |
1994年 | 3篇 |
1993年 | 9篇 |
1992年 | 7篇 |
1991年 | 6篇 |
1990年 | 4篇 |
1989年 | 3篇 |
1987年 | 3篇 |
1986年 | 3篇 |
1985年 | 5篇 |
1984年 | 4篇 |
1982年 | 4篇 |
1981年 | 3篇 |
1979年 | 4篇 |
1975年 | 2篇 |
1973年 | 2篇 |
1964年 | 2篇 |
1963年 | 2篇 |
1958年 | 2篇 |
1957年 | 2篇 |
1956年 | 4篇 |
1955年 | 4篇 |
排序方式: 共有574条查询结果,搜索用时 15 毫秒
111.
112.
In this paper we estimate a flexible form cost function of the aluminium industry in the USA and use our estimates to obtain derived demand curves for aluminium inputs such as electricity and bauxite. We then calculate the welfare gains arising from decreased energy use when the level of secondary recycling is increased. The process is repeated for several model specifications. All of our tests, however, yield similar results and indicate that substitution of scrap for only 5% of the bauxite presently used in US aluminium manufacturing would result in annual savings of close to a quarter of a billion dollars. 相似文献
113.
114.
115.
M. M. Roy 《Die Naturwissenschaften》1956,43(21):497-497
116.
IntroductionThechromiumplaysdualroleinnature .Thechromium (Ⅲ )isessentialforglucoseandlipidmetabolism(Chorvatovicova ,1993) .Ontheotherhand ,excessiveintakeofchromium (Ⅵ )compoundsarepotenttoxicandcarcinogenictothebody (DeFlora ,1990 ) .Hepaticandrenaltoxicityisthemo… 相似文献
117.
A simple HG-AAS technique has been evaluated and standardised for rapid speciation of As(III) and As(V) in a number of contaminated groundwater samples of West Bengal, India. Citric acid has been used for selective hydride formation of As(III). The sensitivity of the evaluated HG-AAS method is 7.91 mg(-1)l, standard deviation, 0.001 and detection limit, 0.4 microg l(-1). As(III) sensitivity remains constant in the sample pH range of 2.3-10.6. Concomitant mineral matrix of the water samples did not interfere with arsenic determination. Eight out of ten groundwater samples analysed for As(IlI)and As(V) contain more As(III), which lies in the range of 54-350 ppb. As(III) estimation in drinking water along with total arsenic should be invoked as a policy for a realistic risk assessment of the contaminated water. 相似文献
118.
Accumulation of 14C labelled bis(tributyltin) oxide (TBTO) by the mud crab, , was determined through short-term exposure to labelled water and food. The potential for trophic accumulation during chronic low level exposure is emphasized. 相似文献
119.
Methylcyclopentadienyl manganese tricarbonyl (MMT) has been used in Canada since 1976 as an antiknock agent in gasoline, completely replacing Pb in 1990. An early study of much higher Mn concentrations in gasoline showed that the combustion of MMT leads to the formation of inorganic manganese oxides, especially Mn3O4. Recent emission testing by Lawrence Livermore National Laboratory for Ethyl Corp. has shown that Mn is primarily emitted as a phosphate or sulfate along with minor amounts of oxides. The main objective of this research was to analyze the deposition of Mn from MMT to the terrestrial environment beside the major highways in the greater Toronto area (GTA), Canada. The results were compared with Pb and other trace elements such as Al, Ca, Fe, Mg, Cu, Zn, Na, and the Cl ion (water extractable) to study the behavior of Mn in soil. The study area was located near major Toronto highways 401 (urban) and 400 (rural), at 43 degrees 67' N and 79 degrees 37' W (latitude and longitude) (278,560 and 47,835 cars/day), respectively. Surface soil samples (0-5 cm depth) were collected at distances up to 40 m from the roadside. Parameters evaluated included total and available Mn and other trace elements, particle size, pH, organic content, and cation exchange capacity. Based on high traffic density along 401, higher Mn deposition was expected. No significant differences were found between the 401 and 400 Barrie (E(+1)) sites, attributable to the natural background levels of Mn or its contribution by other sources such as Mn-enriched road dust or naturally occurring crustal Mn. However, the 400 King City (E(+2)) site had significantly lower Mn levels than did the other three sites, 401 and 400 Barrie. This may be explained by the types of soil along the 401 and 400 sites. The King City site along 400 was found to be higher in sand content than were the 401 sites. A higher sand content could result in higher leaching of Mn to the bottom layer of the soil. Although MMT has been used continuously for approximately 25 years in Canada, its contribution to the terrestrial environment has been very low and has not significantly increased Mn levels along the highways, as demonstrated by this study. 相似文献
120.
Sapozhnikova Y Zubcov N Hungerford S Roy LA Boicenco N Zubcov E Schlenk D 《Chemosphere》2005,60(2):196-205
The Dniester River is one of the largest rivers in Eastern Europe and receives input from numerous anthropogenic activities. In October 2001, fish samples (Abramis brama, Rutilus rutilus heckeli, Perca fluviatilis, Chondrostoma nasus, Carassius auratus gibelio, and Cyprinus carpio) were collected and analyzed for metals and various pesticides. Maximum total DDT pesticide concentrations were between 27.7 and 34.2 ng/g wet weight in muscles and gonads, respectively. DDE isomers comprised up to 70% of total DDT measurement in fish tissues, indicating historical rather than recent DDT pollution. Chlordane and lindane were also detected in amounts up to 37 and 76 ng/g wet weight in gonads, respectively. Among organophosphorous pesticides, malathion showed extremely high concentrations--3 microg/g wet weight in muscles and 46 microg/g wet weight in gonads, indicating recent exposure. Copper concentrations in muscles (1.8-7.2 microg/g) exceeded Threshold Effect Concentrations for copper in fish. Detection of high concentrations of malathion and copper in fish tissues indicated potential anthropogenic stress for more sensitive aquatic biota, likely from agricultural sources in the Dniester River. 相似文献