全文获取类型
收费全文 | 49190篇 |
免费 | 456篇 |
国内免费 | 325篇 |
专业分类
安全科学 | 1212篇 |
废物处理 | 2197篇 |
环保管理 | 6675篇 |
综合类 | 7763篇 |
基础理论 | 13853篇 |
环境理论 | 31篇 |
污染及防治 | 11870篇 |
评价与监测 | 3328篇 |
社会与环境 | 2749篇 |
灾害及防治 | 293篇 |
出版年
2022年 | 267篇 |
2021年 | 273篇 |
2019年 | 308篇 |
2018年 | 1878篇 |
2017年 | 1767篇 |
2016年 | 1874篇 |
2015年 | 791篇 |
2014年 | 955篇 |
2013年 | 3134篇 |
2012年 | 1597篇 |
2011年 | 2816篇 |
2010年 | 1983篇 |
2009年 | 1903篇 |
2008年 | 2433篇 |
2007年 | 2814篇 |
2006年 | 1602篇 |
2005年 | 1373篇 |
2004年 | 1355篇 |
2003年 | 1335篇 |
2002年 | 1298篇 |
2001年 | 1610篇 |
2000年 | 1134篇 |
1999年 | 716篇 |
1998年 | 569篇 |
1997年 | 556篇 |
1996年 | 588篇 |
1995年 | 632篇 |
1994年 | 582篇 |
1993年 | 538篇 |
1992年 | 560篇 |
1991年 | 512篇 |
1990年 | 513篇 |
1989年 | 523篇 |
1988年 | 454篇 |
1987年 | 395篇 |
1986年 | 388篇 |
1985年 | 417篇 |
1984年 | 416篇 |
1983年 | 437篇 |
1982年 | 428篇 |
1981年 | 395篇 |
1980年 | 368篇 |
1979年 | 372篇 |
1978年 | 317篇 |
1977年 | 278篇 |
1976年 | 256篇 |
1975年 | 242篇 |
1974年 | 248篇 |
1973年 | 245篇 |
1972年 | 274篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
841.
842.
843.
844.
845.
R.D. Fleming J.R. Allsup T.R. French D.E. Eccleston 《Journal of the Air & Waste Management Association (1995)》2013,63(6):451-458
Air pollutants in exhaust gas produced from LP-gas (propane) were studied using both laboratory engines and vehicles. The objective of the study was both to evaluate propane as a low-pollution fuel and to provide information on adjustment of engine parameters for advantageous use of propane as a low-pollution fuel. Variables in the study were air-fuel ratio (A/F), ignition timing schedule, and ambient temperature. Data comparable to that for propane relating A/F and ambient temperature to emissions are shown for natural gas and for gasoline. 相似文献
846.
Gene E. Likens 《Ambio》2021,50(2):278
Early studies published in Ambio showed large-scale acidification of lakes in southern Sweden and Norway from acid rain. These studies were important for delimiting various scientific issues and thus for eventually contributing to legislation, which reduced emissions of sulfur dioxide and nitrogen oxides and helped to mitigate this major environmental problem. Long-term studies and monitoring in Sweden and Norway and at Hubbard Brook Experimental Forest in New Hampshire helped guide this legislation in Europe and in the USA. 相似文献
847.
Vega-Millán Christian B. Dévora-Figueroa Ana G. Burgess Jefferey L. Beamer Paloma I. Furlong Melissa Lantz R. Clark Meza-Figueroa Diana O´Rourke Mary Kay García-Rico Leticia Meza-Escalante Edna R. Balderas-Cortés José J. Meza-Montenegro Maria M. 《Environmental science and pollution research international》2021,28(26):34355-34366
Environmental Science and Pollution Research - Environmental arsenic exposure in adults and children has been associated with a reduction in the expression of club cell secretory protein (CC16) and... 相似文献
848.
Jacqueline T. Bangm Jessica L. Reiner Hannes Both Theresa M. Cantu Marco A. Gouws Matthew P. Guillette Jeremy P. Koelmel Wilmien J. Luus-Powell Jan Myburgh Olivia Rynders Joseph R. Sar Willem J. Smit John A. Bowden 《环境科学学报(英文版)》2017,29(11):59-67
This study examined concentrations of 15 perfluoroalkyl acids (PFAAs) in tissues from male Mozambique tilapia (Oreochromis mossambicus) collected at Loskop Dam, Mpumalanga, South Africa in 2014 and 2016. Nine of the 15 PFAAs were detected frequently and were included in statistical analysis and included two of the most commonly known PFAAs, perfluorooctanesulfonic acid (PFOS) (median, 41.6 ng/g) and perfluorooctanoic acid (PFOA) (median, 0.0825 ng/g). Of the tissues measured, plasma (2016 and 2014 median, 22.2 ng/g) contained the highest PFAA burden followed by (in descending order): liver (median, 11.6 ng/g), kidney (median, 9.04 ng/g), spleen (median, 5.92 ng/g), adipose (median, 2.54 ng/g), and muscle (median, 1.11 ng/g). Loskop Dam tilapia have been affected by an inflammatory disease of the adipose tissue known as pansteatitis, so this study also aimed to investigate relationships between PFAA tissue concentrations and incidence of pansteatitis or fish health status. Results revealed that healthy tilapia exhibited an overall higher (p-value < 0.05) PFAA burden than pansteatitis-affected tilapia across all tissues. Further analysis showed that organs previously noted in the literature to contain the highest PFAA concentrations, such as kidney, liver, and plasma, were the organs driving the difference in PFAA burden between the two tilapia groups. Care must be taken in the interpretations we draw from not only the results of our study, but also other PFAA measurements made on populations (human and wildlife alike) under differing health status. 相似文献
849.
In this Concepts & Synthesis paper, we expand the definition of chronodisruption in humans by proposing that it can be operationalized as the split nexus of internal and external times. With this premise, we suggest how chronotype may be used as a temporal marker (chronomarker) of exposure to chronodisruption in studies of cancer, and beyond, offer cancer risk predictions for observational research on the basis of a chronotype-related hypothesis and corollary, and point to first empirical data in humans. In an a priori way, we examine possible outcomes and perspectives for preventive measures following from our rationale and the suggested chronobiology-driven studies and close with overall advances of chronodisruption research. 相似文献
850.
Jaime E. Jiménez Aldo M. Arriagada Francisco E. Fontúrbel Patricio A. Camus M. Isidora Ávila-Thieme 《Die Naturwissenschaften》2013,100(8):779-787
Salmon farming is a widespread activity around the world, also known to promote diverse environmental effects on aquatic ecosystems. However, information regarding the impact of salmon farming on bird assemblages is notably scarce. We hypothesize that salmon farming, by providing food subsidies and physical structures to birds, will change their local community structure. To test this hypothesis, we conducted a seasonal monitoring of bird richness, abundance, and composition at paired salmon pen and control plots in two marine and two lake sites in southern Chile, from fall 2002 to summer 2004. Overall, salmon farming had no significant effects on species richness, but bird abundance was significantly and noticeably higher in salmon pens than in controls. Such aggregation was mainly accounted for by the trophic guilds of omnivores, diving piscivores, carrion eaters, and perching piscivores, but not by invertebrate feeders, herbivores, and surface feeders. Species composition was also significantly and persistently different between salmon pens and controls within each lake or marine locality. The patterns described above remained consistent across environment types and seasons indicating that salmon farming is changing the community structure of birds in both lake and marine habitats by promoting functional and aggregation responses, particularly by favoring species with broader niches. Such local patterns may thus anticipate potential threats from the ongoing expansion of the salmon industry to neighboring areas in Chile, resulting in regional changes of bird communities, toward a less diverse one and dominated by opportunistic, common, and generalist species such as gulls, vultures, and cormorants. 相似文献