全文获取类型
收费全文 | 322篇 |
免费 | 2篇 |
国内免费 | 4篇 |
专业分类
安全科学 | 2篇 |
废物处理 | 4篇 |
环保管理 | 21篇 |
综合类 | 49篇 |
基础理论 | 164篇 |
环境理论 | 1篇 |
污染及防治 | 49篇 |
评价与监测 | 17篇 |
社会与环境 | 19篇 |
灾害及防治 | 2篇 |
出版年
2023年 | 23篇 |
2022年 | 28篇 |
2021年 | 15篇 |
2020年 | 2篇 |
2019年 | 18篇 |
2018年 | 17篇 |
2017年 | 15篇 |
2016年 | 12篇 |
2015年 | 9篇 |
2014年 | 14篇 |
2013年 | 23篇 |
2012年 | 21篇 |
2011年 | 17篇 |
2010年 | 20篇 |
2009年 | 12篇 |
2008年 | 16篇 |
2007年 | 12篇 |
2006年 | 7篇 |
2005年 | 7篇 |
2004年 | 4篇 |
2003年 | 7篇 |
2002年 | 7篇 |
2001年 | 3篇 |
2000年 | 1篇 |
1999年 | 5篇 |
1998年 | 5篇 |
1997年 | 2篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1992年 | 1篇 |
1988年 | 1篇 |
1958年 | 1篇 |
排序方式: 共有328条查询结果,搜索用时 15 毫秒
31.
FRANCISCO PALOMARES JOSÉ ANTONIO GODOY JOSÉ VICENTE LÓPEZ‐BAO ALEJANDRO RODRÍGUEZ SEVERINE ROQUES MIREIA CASAS‐MARCE ELOY REVILLA MIGUEL DELIBES 《Conservation biology》2012,26(4):689-697
Abstract: Theory suggests that demographic and genetic traits deteriorate (i.e., fitness and genetic diversity decrease) when populations become small, and that such deterioration could precipitate positive feedback loops called extinction vortices. We examined whether demographic attributes and genetic traits have changed over time in one of the 2 remaining small populations of the highly endangered Iberian lynx (Lynx pardinus) in Doñana, Spain. From 1983 to 2008, we recorded nontraumatic mortality rates, litter size, offspring survival, age at territory acquisition, and sex ratio. We combined these demographic attributes with measures of inbreeding and genetic diversity at neutral loci (microsatellites) and genes subjected to selection (major histocompatibility complex). Data on demographic traits were obtained through capture and radio tracking, checking dens during breeding, track surveys, and camera trapping. For genetic analyses, we obtained blood or tissue samples from captured or necropsied individuals or from museum specimens. Over time a female‐biased sex ratio developed, age of territory acquisition decreased, mean litter size decreased, and rates of nontraumatic mortality increased, but there were no significant changes in overall mortality rates, standardized individual heterozygosity declined steadily, and allelic diversity of exon 2 of class II major histocompatibility complex DRB genes remained constant (2 allelic variants present in all individuals analyzed). Changes in sex ratio and age of territory acquisition may have resulted from demographic stochasticity, whereas changes in litter size and nontraumatic mortality may be related to observed increases in inbreeding. Concomitant deterioration of both demographic attributes and genetic traits is consistent with an extinction vortex. The co‐occurrence, with or without interaction, of demographic and genetic deterioration may explain the lack of success of conservation efforts with the Doñana population of Iberian lynx. 相似文献
32.
33.
MarÍA JOSÉ Ruiz‐López Natalia Gañan José Antonio Godoy Ana Del Olmo Julian Garde Gerardo Espeso Astrid Vargas Fernando Martinez Eduardo R. S. Roldán Montserrat Gomendio 《Conservation biology》2012,26(6):1121-1129
The relation among inbreeding, heterozygosity, and fitness has been studied primarily among outbred populations, and little is known about these phenomena in endangered populations. Most researchers conclude that the relation between coefficient of inbreeding estimated from pedigrees and fitness traits (inbreeding‐fitness correlations) better reflects inbreeding depression than the relation between marker heterozygosity and fitness traits (heterozygosity‐fitness correlations). However, it has been suggested recently that heterozygosity‐fitness correlations should only be expected when inbreeding generates extensive identity disequilibrium (correlations in heterozygosity and homozygosity across loci throughout the genome). We tested this hypothesis in Mohor gazelle (Gazella dama mhorr) and Iberian lynx (Lynx pardinus). For Mohor gazelle, we calculated the inbreeding coefficient and measured heterozygosity at 17 microsatellite loci. For Iberian lynx, we measured heterozygosity at 36 microsatellite loci. In both species we estimated semen quality, a phenotypic trait directly related to fitness that is controlled by many loci and is affected by inbreeding depression. Both species showed evidence of extensive identity disequilibrium, and in both species heterozygosity was associated with semen quality. In the Iberian lynx the low proportion of normal sperm associated with low levels of heterozygosity was so extreme that it is likely to limit the fertility of males. In Mohor gazelle, although heterozygosity was associated with semen quality, inbreeding coefficient was not. This result suggests that when coefficient of inbreeding is calculated on the basis of a genealogy that begins after a long history of inbreeding, the coefficient of inbreeding fails to capture previous demographic information because it is a poor estimator of accumulated individual inbreeding. We conclude that among highly endangered species with extensive identity disequilibrium, examination of heterozygosity‐fitness correlations may be an effective way to detect inbreeding depression, whereas inbreeding‐fitness correlations may be poor indicators of inbreeding depression if the pedigree does not accurately reflect the history of inbreeding. Correlaciones Heterocigosidad‐ Adaptabilidad y Depresión Endogámica en Dos Especies de Mamíferos Críticamente en Peligro 相似文献
34.
35.
Raymond Philippe Paul Sylvianne Perron André Bellehumeur Christian Larocque Émilie Charest Hugues 《Food and environmental virology》2022,14(1):40-58
Food and Environmental Virology - Human noroviruses are among the main causes of acute gastroenteritis worldwide. Frozen raspberries have been linked to several norovirus food-related outbreaks.... 相似文献
36.
The Science of Nature - The Langenberg Quarry near Bad Harzburg has yielded the first Jurassic stem therian mammal of Germany, recovered from Kimmeridgian (Late Jurassic) near shore deposits of a... 相似文献
37.
38.
Fr d rique Barbier Fr d ric Plassard G rard Duc Michelle Petit-Ramel 《Chemistry and Ecology》2002,18(3):177-186
In order to prevent contamination of subsoil and groundwater by leachates containing heavy metals, montmorillonite linings are used on landfill bottoms. It is therefore important to understand ion uptake by this clay. In this study we have performed percolation of lead(II) and cadmium(II) through columns filled firstly with a technical bentonite and then with a reference bentonite. Elution curves provide an evaluation of metals retention. After the percolation step, columns are cut and metal ions are extracted to evaluate influence of side effects and soil depth on metal uptake. Moreover retentions of lead(II) and cadmium(II) are compared. 相似文献
39.
40.