首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   745篇
  免费   37篇
  国内免费   4篇
安全科学   42篇
废物处理   121篇
环保管理   120篇
综合类   109篇
基础理论   175篇
环境理论   4篇
污染及防治   122篇
评价与监测   36篇
社会与环境   44篇
灾害及防治   13篇
  2023年   6篇
  2022年   10篇
  2021年   16篇
  2020年   14篇
  2019年   18篇
  2018年   30篇
  2017年   29篇
  2016年   40篇
  2015年   33篇
  2014年   19篇
  2013年   60篇
  2012年   30篇
  2011年   46篇
  2010年   39篇
  2009年   45篇
  2008年   38篇
  2007年   45篇
  2006年   40篇
  2005年   27篇
  2004年   21篇
  2003年   15篇
  2002年   17篇
  2001年   9篇
  2000年   9篇
  1999年   11篇
  1998年   8篇
  1997年   8篇
  1996年   8篇
  1995年   6篇
  1994年   3篇
  1993年   6篇
  1992年   6篇
  1991年   10篇
  1990年   5篇
  1989年   4篇
  1986年   6篇
  1984年   2篇
  1981年   2篇
  1972年   2篇
  1971年   2篇
  1961年   3篇
  1959年   2篇
  1958年   2篇
  1957年   5篇
  1955年   5篇
  1954年   2篇
  1940年   2篇
  1937年   1篇
  1934年   1篇
  1926年   1篇
排序方式: 共有786条查询结果,搜索用时 609 毫秒
551.
In selecting six keywords from the environmental discourse the authors argue that language's 'double motivation' reveals a dialectical structure through which it simultaneously expresses both a utopian narrative and an ideologically driven myth of totality and consensus. The ambiguity of these keywords is of critical significance to all those involved in the environmental discourse, for without agreement on the meaning of commonly used concepts effective policy development is potentially disabled. The keywords we explore are 'community', 'sustainability', 'globalisation', 'diversity', 'democracy' and 'environment' itself.  相似文献   
552.
ABSTRACT: During recent years many countries have moved to rationalize the management of state owned or state controlled resources. In Victoria, Australia, water, in particular, has received a great deal of attention. Subsidies to construct, operate, and rehabilitate irrigation facilities have been reduced, and there have been numerous consolidations of small water supply authorities to achieve economies of scale. In addition, Victoria has taken the unusual step of using auctions to allocate new irrigation water entitlements. The six water auctions that took place during 1988 and early 1989 were perceived as an efficient and equitable mechanism to allocate limited water supplies to their highest value use. While the agricultural areas where the different auctions occurred were similar, there was substantial variation in the prices paid, which reflects varying demands for additional irrigation water. This paper will discuss the following topics: the auction process used and the results of the auctions, the efficiency of the auction procedures, and the factors influencing the demand for additional irrigation water in the different auctions. In addition, the implications of using auctions to allocate water supplies for future water management in Victoria will be discussed.  相似文献   
553.
554.
ABSTRACT: The time base of a simulation model can be defined as a combination of two time intervals. One is the interval used for input and internal computations. The second is the interval used for the output and calibration of the model. The time base of a model is related on the one hand to the type of applications for which the simulated data are used, and on the other hand to the structure and complexity of the model. The latter may be represented by the number of parameters employed to specify the operation of the model. Using data typical to relatively small watersheds in a semiarid climate, the interaction between the complexity of a series of models and the time bases used by them was studied. This included the effects of the two factors, time base and complexity, on the values of the optimal parameters, prediction of mean annual flow, and general performance of the models. The main conclusion is that if the acceptable time base is longer, the model can be less complex needing fewer parameters. There is also an advantage in using a time base comprising a shorter input time interval and a longer output time interval.  相似文献   
555.
Differences exist in the spatial structure of cities in both the developed and developing world owing to the contradistinctive nature of their urban growth processes. The structure of Nigerian cities is characterised by the preponderance of mixed land uses resulting primarily due to the organic nature of city growth and more fundamentally, owing to the dynamics of informal urban economic activities. This paper examines mixed land‐use patterns in selected Nigerian cities and appraises their relevance in the general city growth process. By suggesting principles and speculative spatial patterns expressing desirable use combinations, an attempt is made to rationalise the utility of the concept such that its environmental impact is understood and given planning resolution.  相似文献   
556.
In March 1994, China announced its plans for sustainable development in a White Paper entitled 'China's Strategy for Population, Environment and Development in the 21st Century. To achieve the objective of sustainable development; economic, social and environmental aims have to be consistent with each other and meet the needs of the present, without compromising the ability of future generations to meet their own needs. Sustainable development, therefore, encompasses many 'ideals, which need to be introduced through practical management techniques. This paper addresses the role that EIA could play in promoting sustainable development projects in the People's Republic of China by way of the detailed examination of a case study—the Shanghai Second Sewerage Project.  相似文献   
557.
Book reviews     
Ecological Politics in an Age of Risk. Ulrich Beck, translated by Amos Weisz, 1995 Cambridge, Polity Press, first published Germany 1988. ISBN 0 7456 077632, hb £39.50; ISBN 0 7456 13772, pk £12.95

Environmentally Sustainable Business: a local and regional perspective. Peter Roberts, 1995, London, Paul Chapman. ISBN 1 85396 240 6, price not given

Methods of Environmental Impact Assessment. Peter Morris & Riki Therivel (Eds) 1995, London, UCL Press, 378 pp. ISBN 1 85728 117 9, hb £45.00; 1 85728 118 7, pb £14.95

A Guide to Local Environmental Auditing. Hugh Barton & Noel Bruder, 1995, London, Earthscan, 370 pp. ISBN 1 85 383 2340, pb £18.95

Household Waste Recycling. Richard Waite, 1995, London, Earthscan, ISBN 1 8538 3 2421, hb £29.95

A Seed in Time: Proceedings of the 3rd International Conference on Urban and Community Forestry. Forestry Commission, 1994. ISBN 0 885 38 328 3, £9.50 inc p&p (Copies available from: Marcus Sangster, Forestry Commission, 231 Corstorphine Road, Edinburgh EH12 7AT)

Environmental Policy in New Zealand: the politics of clean and green? Tom Buhrs & Robert Bartlett, 1993, Auckland, Oxford University Press viii + 192 pp.

Green Politics. Stephen Rainbow, 1993, Auckland, Oxford University Press xv + 106 pp.

The Future of Community Lands: human resources. E. Ndione, P. DeLeener, M. Ndiaye, P. Jacolin & J.-P. Perier, 1995, London, Intermediate Technology, 236 pp. ISBN 1 339 2480, £14.95  相似文献   
558.
ABSTRACT: This paper discusses the sale of the Government. owned irrigation projects in New Zealand, including the development of irrigation projects in New Zealand, the rationale behind the transfer of ownership to existing irrigators, the sale process, and the outcomes. The transfer of ownership to private entities was undertaken primarily to remove the Government from irrigation activities. However, the sales were also thought to have the poten. tial to improve the efficiency of the projects' operation. The sale process was a negotiated process so that maximizing revenues was not the primary objective of the government. In many cases the government paid irrigators to assume ownership of the schemes. Preliminary data suggest that schemes are being more efficiently operated under private ownership. However, additional data need to be collected on a systematic basis to determine the magnitude of any efficiency gains.  相似文献   
559.
Background: It is documented that male athletes display riskier behaviors while driving (as well as in life in general) than female athletes and nonathletes. However, the literature has reported that athletes show better driving ability than nonathletes. This paradox between behaviors and abilities motivated the present study to further understand the collision risk of varsity athletes.

Objective: The current study estimates the performance differences between varsity male soccer players and male undergraduate nonathletes on (1) a driving task and (2) three perceptual–cognitive tasks (associated with collision risk prediction; i.e., Useful Field of View [UFOV] test).

Methods: Thirty-five male undergraduate students (15 varsity soccer players, 20 undergraduate nonathletes) took part in this study. Driving performance was assessed during 14?min of urban commuting using a driving simulator. While completing the simulated driving task and UFOV test, the physiological responses were monitored using an electrocardiograph (ECG) to document heart rate variability (HRV).

Results: Varsity soccer players showed more risky behaviors at the wheel compared to their nonathlete student peers. Varsity soccer players spent more time over the speed limit, committed more driving errors, and adopted fewer safe and legal behaviors. However, no difference was observed between both groups on driving skill variables (i.e., vehicle control, vehicle mobility, ecodriving). For subtests 1 and 2 of the UFOV (i.e., processing speed, divided attention), both groups performed identically (i.e., 17?ms). The nonathlete group tended to perform better on the selective attention task (i.e., subtest 3 of UFOV test; 63.2?±?6.2?ms vs. 87.2?±?10.7?ms, respectively; this difference was not significant, P = .76).

Conclusion: Preventive driving measures should be enforced in this high-risk population to develop strategies for risk reduction in male team athletes.  相似文献   
560.
Objective: The adaptive behavior of mobile phone–distracted drivers has been a topic of much discussion in the recent literature. Both simulator and naturalistic studies suggest that distracted drivers generally select lower driving speeds; however, speed adaptation is not observed among all drivers, and the mechanisms of speed selection are not well understood. The aim of this research was to apply a driver behavioral adaptation model to investigate the speed adaptation of mobile phone–distracted drivers.

Methods: The speed selection behavior of drivers was observed in 3 phone conditions including baseline (no conversation) and hands-free and handheld phone conversations in a high-fidelity driving simulator. Speed adaptation in each phone condition was modeled as a function of secondary task demand and self-reported personal/psychological characteristics with a system of seemingly unrelated equations (SURE) accounting for potential correlations due to repeated measures experiment design.

Results: Speed adaptation is similar between hands-free and handheld phone conditions, but the predictors of speed adaptation vary across the phone conditions. Though perceived workload of secondary task demand, self-efficacy, attitude toward safety, and driver demographics were significant predictors of speed adaptation in the handheld condition, drivers' familiarity with the hands-free interface, attitude toward safety, and sensation seeking were significant predictors in the hands-free condition. Drivers who reported more positive safety attitudes selected lower driving speeds while using phones.

Conclusion: This research confirmed that behavioral adaptation models are suitable for explaining speed adaptation of mobile phone distracted drivers, and future research could be focused on further theoretical refinement.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号