全文获取类型
收费全文 | 29489篇 |
免费 | 325篇 |
国内免费 | 221篇 |
专业分类
安全科学 | 831篇 |
废物处理 | 1060篇 |
环保管理 | 4033篇 |
综合类 | 4677篇 |
基础理论 | 8537篇 |
环境理论 | 21篇 |
污染及防治 | 7699篇 |
评价与监测 | 1745篇 |
社会与环境 | 1240篇 |
灾害及防治 | 192篇 |
出版年
2022年 | 172篇 |
2021年 | 179篇 |
2019年 | 214篇 |
2018年 | 387篇 |
2017年 | 381篇 |
2016年 | 555篇 |
2015年 | 489篇 |
2014年 | 677篇 |
2013年 | 2133篇 |
2012年 | 842篇 |
2011年 | 1252篇 |
2010年 | 1025篇 |
2009年 | 1034篇 |
2008年 | 1251篇 |
2007年 | 1330篇 |
2006年 | 1182篇 |
2005年 | 1004篇 |
2004年 | 1003篇 |
2003年 | 937篇 |
2002年 | 937篇 |
2001年 | 1239篇 |
2000年 | 862篇 |
1999年 | 548篇 |
1998年 | 426篇 |
1997年 | 435篇 |
1996年 | 443篇 |
1995年 | 482篇 |
1994年 | 438篇 |
1993年 | 395篇 |
1992年 | 414篇 |
1991年 | 374篇 |
1990年 | 377篇 |
1989年 | 411篇 |
1988年 | 347篇 |
1987年 | 300篇 |
1986年 | 276篇 |
1985年 | 306篇 |
1984年 | 287篇 |
1983年 | 321篇 |
1982年 | 323篇 |
1981年 | 272篇 |
1980年 | 243篇 |
1979年 | 269篇 |
1978年 | 229篇 |
1977年 | 195篇 |
1976年 | 200篇 |
1975年 | 192篇 |
1974年 | 173篇 |
1973年 | 171篇 |
1972年 | 198篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
961.
M. Noble P. C. Oloffs R. So J. Yee F. Yuen 《Journal of environmental science and health. Part. B》2013,48(5):359-373
Abstract A tubular device has been developed making it possible to obtain layered samples of loosely aggregated, flocculent material from bogs or eutrophic lakes. The samples are up to 50 cm long and 15 cm in diameter. The sampler is free from protuberances and intact, layered samples can be taken. The tubular part of the sampler is about 85 em long, the walls of the lower 25‐cm portion harbouring a pneumatic closing mechanism which is controlled from above the water surface. An extendible handle for manipulating the sampler and for guiding it into place, is fastened to the upper end of the sampling tube. The performance and the operation of the sampler in the field are described. 相似文献
962.
E. Schuepbach E. Uherek A. Ladstätter-Weissenmayer M.J. Jacob 《Atmospheric environment (Oxford, England : 1994)》2009,43(33):5415-5422
In order to promote the next generation of atmospheric scientists, the task Training and Education (T&E) in ACCENT, the European Network of Excellence in Atmospheric Composition Change (www.accent-network.org) has developed and implemented an Integrated Learning Environment (ILE). For school teachers and their students, the Internet-based “Global Change Magazine” provides up-to-date and freely accessible scientific material in English and five other languages. Additionally, T&E has produced online teaching material for early-career scientists. These e-learning modules are now being used in University Master's courses across Europe. T&E also organised training events for early-career scientists, combining scientific content with development in transferable skills, to focus on interdisciplinary collaboration, interaction with senior scientists, communication with stakeholders, and dissemination to the general public. Evaluation based on participant feedback evidences the effectiveness of these events, e.g., in terms of motivation to remain in the field. Methodologies and materials from T&E are being published in a Handbook on Best Practice, intended for both educators and scientists around the globe who are involved in education in the field of air quality and climate change science. 相似文献
963.
T. Hara S. Trini Castelli R. Ohba C.J. Tremback 《Atmospheric environment (Oxford, England : 1994)》2009,43(24):3745-3753
This work is a contribution to a large project, aimed at the development of an advanced environmental assessment modelling system to be used in Japan. The modelling system here considered consisted of the RAMS and HYPACT coupled models. The RAMS code was modified to properly simulate local scale phenomena using a fine mesh size of 250 m. In this direction, the main aim here was to investigate the effect of the choice of the turbulence closure scheme on the dispersion of pollutants. Our modified version of the RAMS/HYPACT model chain was validated using field experiments which were carried out by the Japan Atomic Energy Research Institute (JAERI) in the area of Mt. Tsukuba (Japan). The mean flow, turbulence and concentration fields obtained using two alternative turbulence closure schemes are compared. A discussion on the different performances of the turbulence closures is presented and the influence of the closure schemes over the plume dispersion is investigated. 相似文献
964.
Tao Miaomiao Xu Ying Liu Qingyang Liu Yanju Tian Shili Schauer James J. 《Environmental Chemistry Letters》2023,21(3):1281-1286
Environmental Chemistry Letters - Plants remove efficiently atmospheric pollution by soot particles, yet the mechanisms used by leaves to capture soot particles are unclear. Here, we studied the... 相似文献
965.
R. Coz V. Ouisse C. Artero A. Carpentier A. Crave E. Feunteun J.-M. Olivier B. Perrin F. Ysnel 《Marine Biology》2012,159(6):1375-1388
The aim of this survey was to test a standardised method to follow the demographic evolution of a dense aggregative ‘forest’
population of the temperate gorgonian Eunicella verrucosa (Octocorallia, Gorgoniidae) using in situ photographic recordings. Distribution, density, growth and demographic evolution
of the colonies was compared along two parallel transects. Computer treatment allowed the estimation of the total branch fan
surface area, and the individual growth of tagged colonies was determined by measuring the increase in this surface area,
using consecutive photographs taken at two-year intervals. To integrate the potential bias of branch overlapping, we proposed
a correction factor between the in situ photographic surface area and the surface area of the gorgonian calculated from ex
situ photographic surface area with all branches deployed. The surface-frequency distribution of colonies was converted to
estimated-age-frequency distribution using an estimated growth curve based on the net growth rate. The technique used revealed
significant differences in population structure and the dynamics of gorgonian colonies, as the two transects appeared to be
influenced by different environmental conditions. The recruitment also seemed to vary according to year and transect, resulting
in different densities. Our work showed clear results in characterising the variations of gorgonian demographic evolution
at a small spatial scale; thus, it is assumed that this method could be a sustainable tool for coastal environmental managers. 相似文献
966.
J. M. Bewers 《Chemistry and Ecology》2013,29(1-2):9-23
Abstract Differences between the scientific and environmental policy communities regarding marine environmental protection strategies are discussed in the context of the nature and extent of scientific influence on marine environmental policy. Public perceptions of the nature and severity of marine pollution frequently differ from scientific assessments. the thesis of this paper is that the increasing influence of public perception on marine environmental protection policy is leading to the adoption of simplistic and unnecessarily extreme approaches to marine pollution prevention and to a reduced reliance on science. This trend is illustrated by some recent international developments and some suggestions are made towards enhancing the influence of science on marine protection policy. 相似文献
967.
J. F. Copplestone 《Journal of environmental science and health. Part. B》2013,48(6):683-688
Abstract The importance of field surveys to provide data on acute pesticide hazards is discussed. The types of questions which small field surveys of pesticide exposure should answer are presented. In addition to protective clothing, the value of distance, time, and personal hygiene in reducing exposure are considered. Finally, the importance of an adequate data base for the development of protocols and guidelines for public protection is discussed. 相似文献
968.
The World Development Report 2000–2001 recommends action on three complementary and synergistic fronts for poverty alleviation – promoting opportunity, facilitating empowerment and enhancing security. This paper analyses the Tamilnadu Forestry Project, funded by US$100 million from the Japan Bank for International Cooperation, for community forestry. The project was launched in 1997–1998 in this southern state of India and has evolved into a comprehensive poverty alleviation programme for the forest abutting villages where the proportion of poor people is largest. It endeavours to explain how the project provides the above three elements at the local level for sustainable poverty alleviation. Regeneration of forests, improvement of basic infrastructure through integration of line departments and promotion of alternate livelihoods provide ample economic opportunities. Establishment of Village Forest Councils, and delegation of sufficient powers to these Councils, has empowered the poorest of the poor. Tree assets, promotion of alternate income generation activities and water harvesting structures have provided security by reducing vulnerability to natural vagaries, particularly drought. In this project, the restoration of biodiversity and people development go hand in hand in a synergistic way that makes the project worth replicating elsewhere in the country and other parts of the world, with suitable modifications. 相似文献
969.
James J. Lavelle 《组织行为杂志》2010,31(6):918-923
This paper argues that taking a functionalist perspective can contribute to a more complete understanding of why employees engage in organizational citizenship behavior (OCB). Informed by the volunteerism literature, a number of other‐oriented and self‐oriented functions are identified as predictors of OCB including value‐expression, social, and career‐related motives. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
970.
Lifjeld JT Kleven O Jacobsen F McGraw KJ Safran RJ Robertson RJ 《Behavioral ecology and sociobiology》2011,65(9):1687-1697
When males become more ornamented and reproduce more successfully as they grow older, phenotypic correlations between ornament
exaggeration and reproductive success can be confounded with age effects in cross-sectional studies, and thus say relatively
little about sexual selection on these traits. This is exemplified here in a correlative study of male fertilization success
in a large colony of American barn swallows (Hirundo rustica erythrogaster). Previous studies of this species have indicated that two sexually dimorphic traits, tail length and ventral plumage coloration,
are positively correlated with male fertilization success, and a mechanism of sexual selection by female choice has been invoked.
However, these studies did not control for potential age-related variation in trait expression. Here, we show that male fertilization
success was positively correlated with male tail length but not with plumage coloration. We also show that 1-year-old males
had shorter tails and lower fertilization success than older males. This age effect accounted for much of the covariance between
tail length and fertilization success. Still, there was a positive relationship between tail length and fertilization success
among older males. But as this group consisted of males from different age classes, an age effect may be hidden in this relationship
as well. Our data also revealed a longitudinal increase in both tail length and fertilization success for individual males.
We argue that age-dependent ornament expression and reproductive performance in males complicate inferences about female preferences
and sexual selection. 相似文献