全文获取类型
收费全文 | 97篇 |
免费 | 1篇 |
专业分类
安全科学 | 4篇 |
废物处理 | 5篇 |
环保管理 | 14篇 |
综合类 | 18篇 |
基础理论 | 26篇 |
污染及防治 | 12篇 |
评价与监测 | 4篇 |
社会与环境 | 7篇 |
灾害及防治 | 8篇 |
出版年
2023年 | 3篇 |
2022年 | 2篇 |
2021年 | 2篇 |
2020年 | 2篇 |
2019年 | 3篇 |
2018年 | 6篇 |
2017年 | 1篇 |
2016年 | 7篇 |
2015年 | 2篇 |
2014年 | 4篇 |
2013年 | 6篇 |
2012年 | 3篇 |
2011年 | 3篇 |
2010年 | 5篇 |
2009年 | 8篇 |
2008年 | 7篇 |
2007年 | 4篇 |
2006年 | 2篇 |
2005年 | 2篇 |
2003年 | 3篇 |
2002年 | 1篇 |
2000年 | 2篇 |
1999年 | 2篇 |
1998年 | 1篇 |
1997年 | 2篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1992年 | 2篇 |
1988年 | 1篇 |
1985年 | 2篇 |
1984年 | 1篇 |
1982年 | 1篇 |
1980年 | 2篇 |
1971年 | 1篇 |
1966年 | 1篇 |
1962年 | 2篇 |
排序方式: 共有98条查询结果,搜索用时 31 毫秒
11.
12.
13.
Neethu Kariyil Veettil Nandan Sivasankaran Bijoy Xavier Nelkunnassery Dominic Don Jayachandran Paravanparambil Rajakumar Anu Pashnath Raghu Midhun Alungal Manikandan Mohan Dhandapani Marigoudar Shambanagouda R. 《Environmental science and pollution research international》2021,28(2):1775-1788
Environmental Science and Pollution Research - The southwest coast of India along the Cochin region is seriously affected by metal contamination from increasing industrial activities. This... 相似文献
14.
Charlie A. R. Hogg Galen C. Egan Nicholas T. Ouellette Jeffrey R. Koseff 《Environmental Fluid Mechanics》2018,18(2):383-394
Gravity currents descending along slopes have typically been studied in quiescent environments, despite the fact that in many geophysical settings there is significant externally driven motion. Here we investigate how the head of a gravity current is influenced by interfacial internal waves at the pycnocline of a two-layer ambient water column. Our experimental measurements show that larger amplitude internal waves, interacting with the gravity current, reduce both the mass transport by the gravity current and its thickness. These results suggest that the ambient internal wave field should be considered when estimating transport by gravity currents in geophysical settings with strong internal waves, such as lakes and the coastal ocean. 相似文献
15.
Agroforests can play an important role in biodiversity conservation in complex landscapes. A key factor distinguishing among agroforests is land-use history – whether agroforests are established inside forests or on historically forested but currently open lands. The disparity between land-use histories means the appropriate biodiversity baselines may differ, which should be accounted for when assessing the conservation value of agroforests. Specifically, comparisons between multiple baselines in forest and open land could enrich understanding of species’ responses by contextualizing them. We made such comparisons based on data from a recently published meta-analysis of the effects of cocoa (Theobroma cacao) agroforestry on bird diversity. We regrouped rustic, mixed shade cocoa, and low shade cocoa agroforests, based on land-use history, into forest-derived and open-land-derived agroforests and compared bird species diversity (species richness, abundance, and Shannon's index values) between forest and open land, which represented the 2 alternative baselines. Bird diversity was similar in forest-derived agroforests and forests (Hedges’ g* estimate [SE] = -0.3144 [0.3416], p = 0.36). Open-land-derived agroforests were significantly less diverse than forests (g* = 1.4312 [0.6308], p = 0.023) and comparable to open lands (g* = -0.1529 [0.5035], p = 0.76). Our results highlight how land-use history determined the conservation value of cocoa agroforests. Forest-derived cocoa agroforests were comparable to the available – usually already degraded – forest baselines, but entail future degradation risks. In contrast, open-land-derived cocoa agroforestry may offer restoration opportunities. Our results showed that comparisons among multiple baselines may inform relative contributions of agroforestry systems to bird conservation on a landscape scale. 相似文献
16.
17.
Rocky Mountain bighorn rams use three distinct tactics in competition for mates. Two tactics (tending and blocking) feature
defense and cooperative mating over a relatively prolonged consort period (up to 3 days). In the coursing tactic, subordinate
rams fight dominants for temporary copulatory access (lasting seconds) to defended ewes. By combining population-wide genetic
(microsatellite) exclusion of paternity, behavioral data and a model of bighorn reproductive competition, we estimated that
coursing rams fathered 44% of 142 lambs assigned paternity in two natural populations. In one population, the probability
of successful defense against coursing was lowest among rams that had many female consorts and held highest dominance rank.
Even so, per capita annual male reproductive success was positively associated with social rank in both herds when measured
in terms of fall conceptions. The proportion of coursing versus defending ram matings in each population (0.36 and 0.39) was
similar to the corresponding fraction of lambs (0.43 and 0.47) fathered by coursing rams, suggesting that sperm competition
approximated a fair lottery. Male traits important in gaining social status and obtaining cooperative consorts with ewes were
different and potentially in conflict with those needed to defend against (and practise) coursing. Although the concussive
weapons (horns) of rams are less dangerous than, for example, the piercing weapons of other bovids, injury from falls and
horn blows during coursing brawls may cause death, handicap future mating competition or increase the risk of predation. Coursing
is a rare example of an unconventional alternative mating tactic that is high-gain and high-risk.
Received: 17 April 1996 / Accepted after revision: 15 March 1997 相似文献
18.
Rates of nitrogen fixation on coral reefs across the continental shelf of the central Great Barrier Reef 总被引:3,自引:0,他引:3
C. R. Wilkinson D. McB. Williams P. W. Sammarco R. W. Hogg L. A. Trott 《Marine Biology》1984,80(3):255-262
This study was undertaken in 1981 to determine whether there were major variations in potential rates of nitrogen fixation on apparently bare coralline substrate from reefs across the continental shelf of the central Great Barrier Reef. Nitrogen fixation, measured as rates of ethylene production (nmol cm-2h-1), was significantly lower on substrata from two inner-shelf reefs, (0.46 and 1.07) than on two middle-shelf reefs (2.10 and 2.97) and on two outer-shelf reefs (3.20 and 3.81). By contrast, algal biomass (mg cm-2) on experimental substrate was significantly higher on inner-shelf reefs (80.8 and 59.4) than on middleshelf (27.1 and 23.8) and outer-shelf reefs (26.4 and 22.4). The rate of nitrogen fixation was positively correlated with the proportion of bare substratum and significantly higher concentrations of dissolved inorganic nitrogen were found in waters over the reefs than in water flowing onto those reefs. The abundance of algal-grazing fishes was reported previously to be significantly lower on inner-shelf reefs. It is suggested that this cross-shelf variation in the activity of algal-grazing fishes may be a determinant of the observed cross-shelf variations in potential nitrogen fixation.Contribution No. 233 from the Australian Institute of Marine Science 相似文献
19.
20.
Dominic Stead 《国际发展与全球生态学杂志》2013,20(4):312-323
Scenario analysis is a technique that is increasingly being used as a way of identifying future policy options and issues in the long-term. This paper discusses the role of scenario analysis in policy development in relation to future transport policy. It discusses three key stages in scenario analysis: the identification of policy targets; the development of images of the future; and the construction of policy packages. 相似文献