全文获取类型
收费全文 | 663篇 |
免费 | 12篇 |
国内免费 | 9篇 |
专业分类
安全科学 | 20篇 |
废物处理 | 15篇 |
环保管理 | 109篇 |
综合类 | 81篇 |
基础理论 | 156篇 |
环境理论 | 12篇 |
污染及防治 | 174篇 |
评价与监测 | 64篇 |
社会与环境 | 49篇 |
灾害及防治 | 4篇 |
出版年
2023年 | 5篇 |
2022年 | 11篇 |
2021年 | 8篇 |
2020年 | 9篇 |
2019年 | 12篇 |
2018年 | 28篇 |
2017年 | 27篇 |
2016年 | 26篇 |
2015年 | 21篇 |
2014年 | 23篇 |
2013年 | 49篇 |
2012年 | 34篇 |
2011年 | 53篇 |
2010年 | 33篇 |
2009年 | 27篇 |
2008年 | 49篇 |
2007年 | 35篇 |
2006年 | 43篇 |
2005年 | 23篇 |
2004年 | 15篇 |
2003年 | 33篇 |
2002年 | 23篇 |
2001年 | 7篇 |
2000年 | 7篇 |
1999年 | 11篇 |
1998年 | 8篇 |
1997年 | 10篇 |
1996年 | 4篇 |
1995年 | 4篇 |
1994年 | 9篇 |
1993年 | 3篇 |
1992年 | 7篇 |
1991年 | 2篇 |
1990年 | 1篇 |
1989年 | 3篇 |
1987年 | 1篇 |
1986年 | 2篇 |
1985年 | 2篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1982年 | 3篇 |
1981年 | 2篇 |
1979年 | 3篇 |
1978年 | 1篇 |
1976年 | 3篇 |
1973年 | 1篇 |
1964年 | 1篇 |
排序方式: 共有684条查询结果,搜索用时 15 毫秒
681.
Following the introduction to a new area (pre-border dispersal), post-border processes determine the success in the establishment of non-indigenous species (NIS). However, little is known on how these post-border processes shape the genetic composition of NIS at regional scales. Here, we analyse genetic variation in introduced populations along impacted coastlines to infer demographic and kinship dynamics at the post-border stage. We used as a model system the ascidian species Microcosmus squamiger that has been introduced worldwide. This species can colonize and grow fast on man-made artificial structures, impacting activities such as mariculture. However, it can also establish itself on natural substrates, thus altering natural communities and becoming an ecological problem. We genotyped 302 individuals from eight populations established on natural and artificial substrates in the north-western Mediterranean Sea, using six microsatellite loci. We then compared the resulting genotypes with those found within the native range of the species. We found high levels of genetic diversity and allelic richness in all populations, with an overall deficit of heterozygotes. Autocorrelation analyses showed that there was no within-population genetic structure (at a scale of tens of metres); likewise, no significant differentiation in pairwise comparisons between populations (tens of kilometres apart) and no isolation-by-distance pattern was found. The results suggest that M. squamiger has a natural capacity for high dispersal from one patch of hard substrate to another and no differences whatsoever could be substantiated between natural and artificial substrates. Interestingly, two groups of genetically differentiated individuals were detected that were associated with the two ancestral source areas of the worldwide expansion of the species. Individual assignment tests showed the coexistence of individuals of these two clusters in all populations but with little interbreeding among them as the frequency of admixed individuals was only 15 %. The mechanism responsible for maintaining these genetic pools unmixed is unknown, but it does not appear to compromise post-border colonization of introduced populations. 相似文献
682.
This study was undertaken to further clarify whether the brown shrimp, Crangon crangon (Linnaeus 1758), is a gonochorist, a facultative or an obligate hermaphrodite. Juvenile shrimps were sampled from intertidal habitats along the German Wadden Sea coast with a push net and from a power plant water inlet to quantify the share of primary females. Length-based sex ratios were determined for about 27,000 individuals using external characteristics. Observed sex ratios were mainly female-biased, and also large males occurred regularly in the catch. This indicates that sex at hatch is not male as would be characteristic for an obligate protandric hermaphrodite and that not all male shrimps change sex. A cohort-based computer simulation, including sex-specific growth rates, mortality and seasonally varying recruitment, generated sex ratios comparable to the field. The observed decline in the proportion of males with increasing size can be explained solely by faster growth of females without involving hermaphroditism. Based on temperature-dependent growth and moult rates as well as length-specific numbers of eggs per female, the potential egg production of primary and secondary females was modelled, yielding contributions of secondary females of <1%. Sex change in C. crangon has previously been observed and may be interpreted as an evolutionary relict of this species having evolved in a habitat characterized by lower population densities, lower predation levels and increased longevity compared to today’s living conditions in North Sea coastal waters. 相似文献
683.
Crini Grégorio Cosentino Cesare Bradu Corina Fourmentin Marc Torri Giangiacomo Ruzimuradov Olim Alaton Idil Arslan Tomei Maria Concetta Derco Ján Barhoumi Mondher Prosen Helena Malinović Borislav N. Vrabeľ Martin Huq Mohammad Mahmudul Soltan Jafar Lichtfouse Eric Morin-Crini Nadia 《Environmental Chemistry Letters》2022,20(4):2597-2628
Environmental Chemistry Letters - Alkylphenols and alkylphenol polyethoxylates are emerging hazardous contaminants due in particular to their endocrine-disrupting properties. These compounds... 相似文献
684.
Morin-Crini Nadia Lichtfouse Eric Fourmentin Marc Ribeiro Ana Rita Lado Noutsopoulos Constantinos Mapelli Francesca Fenyvesi Éva Vieira Melissa Gurgel Adeodato Picos-Corrales Lorenzo A. Moreno-Piraján Juan Carlos Giraldo Liliana Sohajda Tamás Huq Mohammad Mahmudul Soltan Jafar Torri Giangiacomo Magureanu Monica Bradu Corina Crini Grégorio 《Environmental Chemistry Letters》2022,20(2):1333-1375
Environmental Chemistry Letters - The rise of emerging contaminants in waters challenges the scientific community and water treatment stakeholders to design remediation techniques that are simple,... 相似文献