全文获取类型
收费全文 | 666篇 |
免费 | 10篇 |
国内免费 | 5篇 |
专业分类
安全科学 | 37篇 |
废物处理 | 31篇 |
环保管理 | 103篇 |
综合类 | 97篇 |
基础理论 | 147篇 |
污染及防治 | 184篇 |
评价与监测 | 49篇 |
社会与环境 | 27篇 |
灾害及防治 | 6篇 |
出版年
2023年 | 6篇 |
2022年 | 4篇 |
2021年 | 12篇 |
2020年 | 3篇 |
2019年 | 8篇 |
2018年 | 12篇 |
2017年 | 21篇 |
2016年 | 15篇 |
2015年 | 23篇 |
2014年 | 25篇 |
2013年 | 51篇 |
2012年 | 25篇 |
2011年 | 40篇 |
2010年 | 28篇 |
2009年 | 31篇 |
2008年 | 35篇 |
2007年 | 43篇 |
2006年 | 40篇 |
2005年 | 30篇 |
2004年 | 23篇 |
2003年 | 24篇 |
2002年 | 24篇 |
2001年 | 10篇 |
2000年 | 21篇 |
1999年 | 8篇 |
1998年 | 5篇 |
1997年 | 4篇 |
1996年 | 7篇 |
1995年 | 10篇 |
1994年 | 9篇 |
1993年 | 14篇 |
1992年 | 5篇 |
1991年 | 4篇 |
1990年 | 4篇 |
1989年 | 3篇 |
1988年 | 6篇 |
1987年 | 2篇 |
1985年 | 2篇 |
1984年 | 9篇 |
1983年 | 7篇 |
1982年 | 5篇 |
1981年 | 2篇 |
1978年 | 3篇 |
1977年 | 2篇 |
1961年 | 2篇 |
1959年 | 2篇 |
1958年 | 1篇 |
1957年 | 2篇 |
1953年 | 1篇 |
1935年 | 1篇 |
排序方式: 共有681条查询结果,搜索用时 9 毫秒
591.
E. Tobias Krause Christoph Brummel Sarah Kohlwey Markus C. Baier Caroline Müller Francesco Bonadonna Barbara A. Caspers 《Behavioral ecology and sociobiology》2014,68(11):1819-1827
Although birds have recently been shown to possess olfactory abilities and to use chemical cues in communication, limited effort has been made to demonstrate the use of odorants in social contexts. Even less is known regarding the use of odorants in species recognition. The ability to recognize conspecifics should be more pronounced in social species. This study investigated the importance of olfactory cues in species recognition in females of two estrildid finch species with different levels of sociality. Combining odor preference tests with chemical analyses, we surveyed whether female zebra finches and diamond firetails are able to distinguish between the species based on volatile traits and whether individuals exhibit species-specific differences in body odorants. Zebra finches are more social than diamond firetails; nevertheless, both species have an overlapping distribution area. Applying an experimental Y-maze paradigm, we showed that zebra finches can use differences in their species odor fingerprints and displayed a significant preference for the odor of conspecifics over that of heterospecifics, whereas diamond firetails did not reveal a preference. Using gas chromatography and mass spectrometry, we demonstrated that body odorants of the two species were significantly different in relative composition. This finding demonstrates the potential importance of olfactory cues in species recognition, at least in social bird species. Even these two closely related species displayed remarkable differences in their responsiveness to similar chemical cues, which might be caused by species-specific differences in ecology, physiology, or evolution. 相似文献
592.
593.
594.
The migration pathways of heavy metals derived from an area previously in agricultural use was investigated in the Wielkopolski
National Park (mid-western Poland). The heavy metals involved (Cd, Cu, Cr, Pb, Ni and Zn) were determined in groundwater,
the springs that feed Lake Góreckie and the lake itself. In order to show how the heavy metals may be set free and what is
their biological availability, soil and sediment samples were subjected to single-stage extraction, using 0.01 M CaCl2, 0.02 M EDTA, 0.005 M DTPA, 0.1 M HCl, 1 M HCl and de-ionised water. Varying metal concentrations were recorded in the water
samples during the study period (from November 2009 to July 2010), usually with higher values in winter and lower ones in
summer. The seasonal changes may be ascribed to natural processes taking place in the ground- and surface waters of Lake Góreckie.
On the other hand, the concentration levels (mostly of Cd, Pb and Cr) are indicative of anthropogenic activity. It should
be mentioned in this context that the highest metal concentrations were found in the soil layer. The concentrations were also
found to exceed both the Polish and the World Health Organization water-quality standards. It appears that the soils are highly
contaminated, mostly with cadmium. The long-lasting effect of acid precipitation in the area makes it possible for immobile
forms to become mobile, thus facilitating further migration into the environment. 相似文献
595.
We speciated arsenic compounds in marine fish and shellfish from two islands of the United States Territory of American Samoa in the South Pacific, and found that inorganic arsenic occurred as a minor fraction. The proportion of inorganic arsenic was generally far below the levels of prevailing assumptions typically used in human health risk assessments when only total arsenic is analysed. Fish and shellfish were collected from Tutuila and Ofu between May 2001 and March 2002 (n=383 individual specimens, with 117 composites); sites were selected based on habitat type and were representative of those frequented by local fishers. These islands have moderately developed reef fish fisheries among artisanal fishers, are far removed from any industrial or mining sources of arsenic, and presented an opportunity to study arsenic variations in marine biota from un-impacted environments. Target species were from various trophic levels and are among those frequently harvested for human consumption. We found evidence that arsenic concentrated in some marine species, but did not tend to follow classic trophic patterns for biomagnification or bioaccumulation. For the majority of samples, inorganic arsenic was less than 0.5% of total arsenic, with only a few samples in the range of 1-5%, the latter being mollusks which are recognized to have unusually high arsenic levels in general. This work supports the importance of speciation analysis for arsenic, because of the ubiquitous occurrence of arsenic in the environment, and its variable toxicity depending on chemical form. 相似文献
596.
597.
598.
Francesca Romana Grati Denise Molina Gomes Jose Carlos Pinto B. Ferreira Celine Dupont Viola Alesi Laetitia Gouas Nina Horelli-Kuitunen Kwong Wai Choy Sandra García-Herrero Alberto Gonzalez de la Vega Krzysztof Piotrowski Rita Genesio Gloria Queipo Barbara Malvestiti Bérénice Hervé Brigitte Benzacken Antonio Novelli Philippe Vago Kirsi Piippo Tak Yeung Leung Federico Maggi Thibault Quibel Anne Claude Tabet Giuseppe Simoni François Vialard 《黑龙江环境通报》2015,35(8):801-809
599.
600.