全文获取类型
收费全文 | 1977篇 |
免费 | 42篇 |
国内免费 | 11篇 |
专业分类
安全科学 | 129篇 |
废物处理 | 82篇 |
环保管理 | 471篇 |
综合类 | 231篇 |
基础理论 | 501篇 |
环境理论 | 2篇 |
污染及防治 | 386篇 |
评价与监测 | 124篇 |
社会与环境 | 72篇 |
灾害及防治 | 32篇 |
出版年
2024年 | 8篇 |
2023年 | 17篇 |
2022年 | 24篇 |
2021年 | 27篇 |
2020年 | 30篇 |
2019年 | 30篇 |
2018年 | 47篇 |
2017年 | 61篇 |
2016年 | 69篇 |
2015年 | 65篇 |
2014年 | 60篇 |
2013年 | 131篇 |
2012年 | 88篇 |
2011年 | 158篇 |
2010年 | 100篇 |
2009年 | 89篇 |
2008年 | 115篇 |
2007年 | 126篇 |
2006年 | 122篇 |
2005年 | 72篇 |
2004年 | 71篇 |
2003年 | 72篇 |
2002年 | 61篇 |
2001年 | 43篇 |
2000年 | 29篇 |
1999年 | 30篇 |
1998年 | 29篇 |
1997年 | 17篇 |
1996年 | 26篇 |
1995年 | 18篇 |
1994年 | 26篇 |
1993年 | 18篇 |
1992年 | 17篇 |
1991年 | 9篇 |
1990年 | 11篇 |
1989年 | 5篇 |
1988年 | 10篇 |
1987年 | 15篇 |
1986年 | 10篇 |
1985年 | 5篇 |
1984年 | 9篇 |
1983年 | 6篇 |
1982年 | 10篇 |
1981年 | 4篇 |
1980年 | 5篇 |
1979年 | 6篇 |
1969年 | 3篇 |
1936年 | 2篇 |
1935年 | 3篇 |
1926年 | 2篇 |
排序方式: 共有2030条查询结果,搜索用时 15 毫秒
541.
542.
Christopher M. Raymond Ioan Fazey Mark S. Reed Lindsay C. Stringer Guy M. Robinson Anna C. Evely 《Journal of environmental management》2010,91(8):1766-1777
This paper evaluates the processes and mechanisms available for integrating different types of knowledge for environmental management. Following a review of the challenges associated with knowledge integration, we present a series of questions for identifying, engaging, evaluating and applying different knowledges during project design and delivery. These questions are used as a basis to compare three environmental management projects that aimed to integrate knowledge from different sources in the United Kingdom, Solomon Islands and Australia. Comparative results indicate that integrating different types of knowledge is inherently complex – classification of knowledge is arbitrary and knowledge integration perspectives are qualitatively very different. We argue that there is no single optimum approach for integrating local and scientific knowledge and encourage a shift in science from the development of knowledge integration products to the development of problem-focussed, knowledge integration processes. These processes need to be systematic, reflexive and cyclic so that multiple views and multiple methods are considered in relation to an environmental management problem. The results have implications for the way in which researchers and environmental managers undertake and evaluate knowledge integration projects. 相似文献
543.
Ninety-nine human blood samples were collected from the riverine region of northern Sudan and the traditional and mechanized rain-fed areas of western and eastern Sudan, representing areas of limited pesticide use in Sudan. Blood samples were analyzed for organochlorine pesticides by gas liquid chromatography (GLC) followed by electron-capture detection (ECD). p,p′-DDE (a metabolite of DDT), heptachlor epoxide, β-hexachlorocyclohexane (β-HCH), and dieldrin were detected in all locations surveyed. The level of total organochlorine burden was highest in the traditional rain-fed area, followed by the mechanized rain-fed area, and the riverine area. A highly significant correlation was observed between total organochlorine blood burden and the age of the donors (r = 0.608**). 相似文献
544.
Radboud J. Duintjer Tebbens Marita Zimmermann Mark A. Pallansch Kimberly M. Thompson 《Food and environmental virology》2017,9(4):361-382
Poliovirus surveillance plays a critical role in achieving and certifying eradication and will play a key role in the polio endgame. Environmental surveillance can provide an opportunity to detect circulating polioviruses prior to the observation of any acute flaccid paralysis cases. We completed a systematic review of peer-reviewed publications on environmental surveillance for polio including the search terms “environmental surveillance” or “sewage,” and “polio,” “poliovirus,” or “poliomyelitis,” and compared characteristics of the resulting studies. The review included 146 studies representing 101 environmental surveillance activities from 48 countries published between 1975 and 2016. Studies reported taking samples from sewage treatment facilities, surface waters, and various other environmental sources, although they generally did not present sufficient details to thoroughly evaluate the sewage systems and catchment areas. When reported, catchment areas varied from 50 to over 7.3 million people (median of 500,000 for the 25% of activities that reported catchment areas, notably with 60% of the studies not reporting this information and 16% reporting insufficient information to estimate the catchment area population size). While numerous studies reported the ability of environmental surveillance to detect polioviruses in the absence of clinical cases, the review revealed very limited information about the costs and limited information to support quantitative population effectiveness of conducting environmental surveillance. This review motivates future studies to better characterize poliovirus environmental surveillance systems and the potential value of information that they may provide in the polio endgame. 相似文献
545.
546.
The aim of this work is to construct nonseparable, stationary covariance functions for processes that vary continuously in space and time. Stochastic modelling of phenomena over space and time is important in many areas of application. But choice of an appropriate model can be difficult as we need to ensure that we use valid covariance structures. A common choice for the process is a product of purely spatial and temporal random processes. In this case, the resulting process possesses a separable covariance function. Although these models are guaranteed to be valid, they are severely limited, since they do not allow space–time interactions. We propose a general and flexible class of valid nonseparable covariance functions through mixing over separable models. The proposed model allows for different degrees of smoothness across space and time and long‐range dependence in time. Moreover, the proposed class has as particular cases several popular covariance models proposed in the literature such as the Matérn and the Cauchy Class. We use a Markov chain Monte Carlo sampler for Bayesian inference and apply our modelling approach to the Irish wind data. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
547.
1979~1996年期间泰国沿海各府造成红树林减少的经济学和人口学因素 总被引:1,自引:0,他引:1
Edward Barbier Mark Cox 《Ambio-人类环境杂志》2002,31(4):351-357
本文分析了泰国沿海各府确定将红树林转为商业性养虾用地的经济学和人口学因素.因此红树林的转化取决于给养虾人的回报(即虾的价格)、养虾投入的成本(即饲料价格和工人的工资)和红树林地区的"可利用性".另外,人均收入、人口增长和人口的迁入(即养虾场的数量)等外在因素也是很重要的.我们通过对1979~1996年期间泰国沿海21个府进行的分组调查,对红树林的转化和养虾场的扩大进行了实验性调查.结果显示,由于养虾业的发展,虾的价格、最低工资、离市场的距离、饲料价格、人口增长、人均收入以及养虾场的密度都对泰国红树林的转化造成了重要影响. 相似文献
548.
Nest-site selection is an important determinant of individual fitness in birds. Understanding what information individuals use to choose nest sites is therefore important for understanding the evolution of nest-site selection, the dynamics of populations, and the conservation of species. We used five years of mark-recapture data for Mountain Bluebirds (Sialia currucoides) to examine how dispersal probability and nest-site selection vary with potential cues of nest-site quality. Dispersal distance between breeding seasons and nest-site selection were modeled as a function of personal reproductive success, conspecific density, conspecific reproductive success, and habitat type. Between years, the dispersal probability was related to personal reproductive success, not conspecific information, and individuals fledging fewer young dispersed longer distances. For dispersing individuals, the probability that a nest site was selected in year i was negatively related to distance from the nest site selected in year i - 1 for all age and sex classes, and positively related to conspecific density and reproductive success in year i - 1 for both second-year (SY) and after-hatch-year (AHY) females. However, nest-site selection in year i was more strongly related to conspecific density in year i- 1 for hatch-year (HY) females and was much more strongly related to the reproductive success of conspecifics in year i - 1 for AHY females. Nest-site selection of HY and AHY males was not consistently related to the metrics of conspecific information, but we suspect that relationships were obscured by competitive interactions. We found no evidence indicating that individuals respond differently to conspecific information at longer distances, suggesting that individuals limit dispersal to areas where they have prior knowledge. We predict that these patterns of nest-site selection will allow birds to loosely track nest-site quality and maintain an ideal free distribution, where average fitness is equal in all habitat types. 相似文献
549.
550.
Indirect Effects of Feral Horses on Estuarine Communities 总被引:1,自引:1,他引:1
Phillip S. Levin ‡ Julie Ellis Rachel Petrik Mark E. Hay† 《Conservation biology》2002,16(5):1364-1371