全文获取类型
收费全文 | 14482篇 |
免费 | 99篇 |
国内免费 | 158篇 |
专业分类
安全科学 | 350篇 |
废物处理 | 592篇 |
环保管理 | 1569篇 |
综合类 | 3306篇 |
基础理论 | 3368篇 |
环境理论 | 6篇 |
污染及防治 | 3611篇 |
评价与监测 | 1105篇 |
社会与环境 | 760篇 |
灾害及防治 | 72篇 |
出版年
2022年 | 127篇 |
2021年 | 107篇 |
2019年 | 101篇 |
2018年 | 201篇 |
2017年 | 206篇 |
2016年 | 302篇 |
2015年 | 228篇 |
2014年 | 402篇 |
2013年 | 1030篇 |
2012年 | 454篇 |
2011年 | 588篇 |
2010年 | 469篇 |
2009年 | 526篇 |
2008年 | 566篇 |
2007年 | 583篇 |
2006年 | 549篇 |
2005年 | 505篇 |
2004年 | 453篇 |
2003年 | 460篇 |
2002年 | 432篇 |
2001年 | 597篇 |
2000年 | 374篇 |
1999年 | 261篇 |
1998年 | 150篇 |
1997年 | 164篇 |
1996年 | 172篇 |
1995年 | 188篇 |
1994年 | 179篇 |
1993年 | 131篇 |
1992年 | 165篇 |
1991年 | 174篇 |
1990年 | 169篇 |
1989年 | 141篇 |
1988年 | 156篇 |
1987年 | 96篇 |
1986年 | 128篇 |
1985年 | 128篇 |
1984年 | 122篇 |
1983年 | 114篇 |
1982年 | 121篇 |
1981年 | 121篇 |
1980年 | 87篇 |
1979年 | 99篇 |
1978年 | 102篇 |
1976年 | 94篇 |
1974年 | 104篇 |
1972年 | 89篇 |
1967年 | 102篇 |
1966年 | 86篇 |
1964年 | 94篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
371.
Hazel A. Jackson Lawrence Percival-Alwyn Camilla Ryan Mohammed F. Albeshr Luca Venturi Hernán E. Morales Thomas C. Mathers Jonathan Cocker Samuel A. Speak Gonzalo G. Accinelli Tom Barker Darren Heavens Faye Willman Deborah Dawson Lauren Ward Vikash Tatayah Nicholas Zuël Richard Young Lianne Concannon Harriet Whitford Bernardo Clavijo Nancy Bunbury Kevin M. Tyler Kevin Ruhomaun Molly K. Grace Michael W. Bruford Carl G. Jones Simon Tollington Diana J. Bell Jim J. Groombridge Matt Clark Cock Van Oosterhout 《Conservation biology》2022,36(4):e13918
The pink pigeon (Nesoenas mayeri) is an endemic species of Mauritius that has made a remarkable recovery after a severe population bottleneck in the 1970s to early 1990s. Prior to this bottleneck, an ex situ population was established from which captive-bred individuals were released into free-living subpopulations to increase population size and genetic variation. This conservation rescue led to rapid population recovery to 400–480 individuals, and the species was twice downlisted on the International Union for the Conservation of Nature (IUCN) Red List. We analyzed the impacts of the bottleneck and genetic rescue on neutral genetic variation during and after population recovery (1993–2008) with restriction site-associated sequencing, microsatellite analyses, and quantitative genetic analysis of studbook data of 1112 birds from zoos in Europe and the United States. We used computer simulations to study the predicted changes in genetic variation and population viability from the past into the future. Genetic variation declined rapidly, despite the population rebound, and the effective population size was approximately an order of magnitude smaller than census size. The species carried a high genetic load of circa 15 lethal equivalents for longevity. Our computer simulations predicted continued inbreeding will likely result in increased expression of deleterious mutations (i.e., a high realized load) and severe inbreeding depression. Without continued conservation actions, it is likely that the pink pigeon will go extinct in the wild within 100 years. Conservation rescue of the pink pigeon has been instrumental in the recovery of the free-living population. However, further genetic rescue with captive-bred birds from zoos is required to recover lost variation, reduce expression of harmful deleterious variation, and prevent extinction. The use of genomics and modeling data can inform IUCN assessments of the viability and extinction risk of species, and it helps in assessments of the conservation dependency of populations. 相似文献
372.
N. Speybroeck P. J. Lindsey M. Billiouw M. Madder J. K. Lindsey D. L. Berkvens 《Environmental and Ecological Statistics》2006,13(1):69-87
This paper presents statistical methodology to analyze longitudinal binary responses for which a sudden change in the response
occurs in time. Probability plots, transition matrices, and change-point models and more advanced techniques such as generalized
auto-regression models and hidden Markov chains are presented and applied on a study on the activity of Rhipicephalus appendiculatus, the major vector of Theileria parva, a fatal disease in cattle. This study presents individual measurements on female R. appendiculatus, which are terminating their diapause (resting status) and become active. Comprehending activity patterns is very important
to better understand the ecology of R. appendiculatus. The model indicates that activity and non-activity act in an absorbing way meaning that once a tick becomes active it shows
a tendency to remain active. The change-point model estimates that the sudden change in activity happens on December 10. The
reaction of ticks on acceleration and changes in rainfall and temperature indicates that ticks can sense climatic changes.
The study revealed the underlying not visually observable states during diapause development of the adult tick of R. appendiculatus. These states could be related to phases during the dynamic event of diapause development and post-diapause activity in R. appendiculatus. 相似文献
373.
Polyacetylene is presented as the prototype of a metallic conducting polymer. The concepts of one-dimensional metal physics are illustrated and special attention is drawn to a structural defect called “soliton”. Electrical, magnetic, and optical experiments connected with solitons are discussed. The authors' opinion is expressed that present experimental results do not yet furnish strong evidence for the existence of solitons in polyacetylene, but that the soliton idea is a fruitful stimulus for further investigations and novel applications. 相似文献
374.
375.
376.
377.
378.
379.
380.