全文获取类型
收费全文 | 38698篇 |
免费 | 232篇 |
国内免费 | 273篇 |
专业分类
安全科学 | 755篇 |
废物处理 | 2013篇 |
环保管理 | 4638篇 |
综合类 | 6505篇 |
基础理论 | 10414篇 |
环境理论 | 19篇 |
污染及防治 | 9248篇 |
评价与监测 | 3027篇 |
社会与环境 | 2426篇 |
灾害及防治 | 158篇 |
出版年
2023年 | 158篇 |
2022年 | 311篇 |
2021年 | 326篇 |
2020年 | 194篇 |
2019年 | 235篇 |
2018年 | 1852篇 |
2017年 | 1777篇 |
2016年 | 1896篇 |
2015年 | 637篇 |
2014年 | 841篇 |
2013年 | 2104篇 |
2012年 | 1728篇 |
2011年 | 2604篇 |
2010年 | 1613篇 |
2009年 | 1585篇 |
2008年 | 1993篇 |
2007年 | 2373篇 |
2006年 | 1128篇 |
2005年 | 1319篇 |
2004年 | 1334篇 |
2003年 | 1264篇 |
2002年 | 925篇 |
2001年 | 1069篇 |
2000年 | 725篇 |
1999年 | 478篇 |
1998年 | 285篇 |
1997年 | 316篇 |
1996年 | 323篇 |
1995年 | 372篇 |
1994年 | 355篇 |
1993年 | 280篇 |
1992年 | 279篇 |
1991年 | 327篇 |
1990年 | 307篇 |
1989年 | 285篇 |
1988年 | 258篇 |
1987年 | 200篇 |
1986年 | 226篇 |
1985年 | 209篇 |
1984年 | 227篇 |
1983年 | 221篇 |
1982年 | 226篇 |
1981年 | 214篇 |
1980年 | 173篇 |
1979年 | 199篇 |
1978年 | 163篇 |
1977年 | 150篇 |
1976年 | 149篇 |
1974年 | 162篇 |
1967年 | 158篇 |
排序方式: 共有10000条查询结果,搜索用时 19 毫秒
51.
Bhopal Gas Tragedy was the worst industrial accident in the world where several thousand persons lost their lives. It occurred at the Union Carbide plant located inside the city of Bhopal and close to the railway station, at midnight of December 2-3, 1984 due to the leakage of MIC gas which took the local sleeping and floating population unawares.
This paper describes the experience of a transit passenger who reached the Bhopal Railway Station by train at about the same time when the deadly gas leakage occurred. 相似文献
52.
The amounts of total NH
4
+
detected in the external media in which Phascolosoma arcuatum had been exposed to various periods of anoxia were significantly greater than those in which the worms were exposed to normoxia for a similar period. The increased NH
4
+
production by P. arcuatum during anoxic exposure was unlikely to be due to an increased catabolism of adenine nucleotides or urea. In contrast, there were significant decreases in the concentrations of several free amino acids in the coelomic plasma and body tissues of individuals during the 48 h of anoxic exposure. The amount of NH
4
+
produced by the anoxic P. arcuatum could be accounted for by the decreases in the concentrations of aspartate or glycine. Increases in the catabolism of free amino acids (FAA), leading to the increased production of NH
4
+
, in P. arcuatum during anoxia were supported by the detection of significant changes in the kinetic properties of glutamate dehydrogenase (GDH), in the deaminating direction, from worms exposed to anoxia for 48 h. The apparent increase in the affinity of GDH from the anoxic worm to glutamate would bring about a greater deaminating activity at physiological concentrations of ths substrate. P. arcuatum used in these experiments were collected from the mangrove swamp at Mandai, Singapore between 1990 and 1993. 相似文献
53.
M Mora R Skiles B McKinney M Paredes D Buckler D Papoulias D Klein 《Environmental pollution (Barking, Essex : 1987)》2002,116(1):169-176
Peregrine falcons (Falco peregrinus) have been recorded nesting in Big Bend National Park, Texas, USA and other areas of the Chihuahuan Desert since the early 1900s. From 1993 to 1996, peregrine falcon productivity rates were very low and coincided with periods of low rainfall. However, low productivity also was suspected to be caused by environmental contaminants. To evaluate potential impacts of contaminants on peregrine falcon populations, likely avian and bat prey species were collected during 1994 and 1997 breeding seasons in selected regions of western Texas, primarily in Big Bend National Park. Tissues of three peregrine falcons found injured or dead and feathers of one live fledgling also were analyzed. Overall, mean concentrations of DDE [1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene], a metabolite of DDT [1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane], were low in all prey species except for northern rough-winged swallows (Stelgidopteryx serripennis, mean = 5.1 microg/g ww). Concentrations of mercury and selenium were elevated in some species, up to 2.5 microg/g dw, and 15 microg/g dw, respectively, which upon consumption could seriously affect reproduction of top predators. DDE levels near 5 microg/g ww were detected in carcass of one peregrine falcon found dead but the cause of death was unknown. Mercury, selenium, and DDE to some extent, may be contributing to low reproductive rates of peregrine falcons in the Big Bend region. 相似文献
54.
55.
56.
57.
Dr. J. F. Bruch P. Metezeau N. Garcia-Fonknechten Y. Richard V. Tricottet B.-L. Hsi A. Kitzis C. Julien E. Papiernik 《黑龙江环境通报》1991,11(10):787-798
Three monoclonal antibodies (MAbs) against trophoblast (GB17, GB21, and GB25) and flow cytometry were used to sort trophoblast-like cells (TLCs) from peripheral blood of pregnant women. Sorted TLCs were processed for electron microscopy and fetal DNA amplification of the Y-specific sequences from mothers carrying male fetuses. At the ultra-structural level, most of the nucleated cells had the morphology of leucocytes, suggesting maternal contaminants, and we did not find the characteristic features of the free inter-villous trophoblast cells. Nevertheless, polymerase chain reaction (PCR) analysis showed an amplification of Y-specific sequences in two out of three samples of sorted TLCs. These results suggest that besides the maternal leucocytes, sufficient trophoblast nucleated fetal cells can be obtained using cell enrichment by sorting. This sensitive method holds promise for non-invasive prenatal diagnosis of fetal sex and if sufficient Y(positive) nuclei are found, for the diagnosis of selected numerical chromosome abnormalities. 相似文献
58.
59.
The past two decades have witnessed an increase in the exploration for, and development of, mineral resources at Arctic latitudes. Such effort has resulted in the commencement of production at a number of different localities in close proximity to the ocean. Since proximity to a source of transportation for the conveyance of concentrates to the market is a primary requirement governing the economic decisions for the mine to proceed, it is logical that ore deposits near a coastline are primary targets for development.
Closely tied to coastal mining developments is the need to dispose of tailings and waste rock in the most economical manner. Prior to the advent of heightened public awareness and environmental concern, and the enactment of pollution legislation, disposal practices were largely based upon convenience. Currently, however, proposed disposal and operating practices receive closer scrutiny, with a view to providing adequate protection for aquatic resources and habitat. This paper summarizes some of the features of three Arctic mines, wastes from which enter the marine environment, and compares the disposal practices used at each to measures of environmental change as indicated by metal concentrations in various media. 相似文献
Closely tied to coastal mining developments is the need to dispose of tailings and waste rock in the most economical manner. Prior to the advent of heightened public awareness and environmental concern, and the enactment of pollution legislation, disposal practices were largely based upon convenience. Currently, however, proposed disposal and operating practices receive closer scrutiny, with a view to providing adequate protection for aquatic resources and habitat. This paper summarizes some of the features of three Arctic mines, wastes from which enter the marine environment, and compares the disposal practices used at each to measures of environmental change as indicated by metal concentrations in various media. 相似文献
60.
Lawrence B. Cahill 《环境质量管理》1994,3(3):337-342
“Ah, Mr. Cahill, I wonder if you could come back to the auditor's team room. It seems one of your auditors has fallen asleep for the second time this week. I know you had a grueling trip getting here, but this is embarrassing to everyone”. So went an audit I led some time ago. It was not a fun experience, and it has left some scars. There has been much discussion lately in the profession about certifying environmental (health and safety) auditors against certain performance criteria. But how does one evaluate for such important measures as physical stamina?. This article discusses the qualifications that environmental auditors should have if they are to lead or conduct a quality audit. It becomes evident after reviewing these expectations that certifying auditors through a traditional written examination might ignore some of the most important skills an auditor should possess, especially in working with managers throughout an organization. Before certifying organizations progress too far down the restrictive written-exam road, they should determine how these other skills are to be assessed. No amount of book learning can overcome the drawbacks of a poor or combative interviewer or even an exhausted auditor. 相似文献