全文获取类型
收费全文 | 2924篇 |
免费 | 20篇 |
国内免费 | 33篇 |
专业分类
安全科学 | 85篇 |
废物处理 | 155篇 |
环保管理 | 280篇 |
综合类 | 512篇 |
基础理论 | 611篇 |
环境理论 | 2篇 |
污染及防治 | 854篇 |
评价与监测 | 261篇 |
社会与环境 | 197篇 |
灾害及防治 | 20篇 |
出版年
2023年 | 27篇 |
2022年 | 90篇 |
2021年 | 109篇 |
2020年 | 58篇 |
2019年 | 43篇 |
2018年 | 111篇 |
2017年 | 102篇 |
2016年 | 134篇 |
2015年 | 82篇 |
2014年 | 121篇 |
2013年 | 191篇 |
2012年 | 146篇 |
2011年 | 196篇 |
2010年 | 132篇 |
2009年 | 122篇 |
2008年 | 134篇 |
2007年 | 117篇 |
2006年 | 86篇 |
2005年 | 117篇 |
2004年 | 164篇 |
2003年 | 156篇 |
2002年 | 97篇 |
2001年 | 77篇 |
2000年 | 36篇 |
1999年 | 35篇 |
1998年 | 15篇 |
1997年 | 27篇 |
1996年 | 19篇 |
1995年 | 23篇 |
1994年 | 17篇 |
1993年 | 8篇 |
1992年 | 11篇 |
1991年 | 16篇 |
1990年 | 10篇 |
1989年 | 11篇 |
1988年 | 5篇 |
1987年 | 10篇 |
1986年 | 8篇 |
1985年 | 10篇 |
1984年 | 10篇 |
1983年 | 11篇 |
1982年 | 5篇 |
1981年 | 7篇 |
1979年 | 8篇 |
1977年 | 3篇 |
1975年 | 3篇 |
1970年 | 3篇 |
1966年 | 3篇 |
1964年 | 4篇 |
1961年 | 3篇 |
排序方式: 共有2977条查询结果,搜索用时 15 毫秒
981.
Büker P Emberson LD Ashmore MR Cambridge HM Jacobs CM Massman WJ Müller J Nikolov N Novak K Oksanen E Schaub M de la Torre D 《Environmental pollution (Barking, Essex : 1987)》2007,146(3):726-735
A multiplicative and a semi-mechanistic, BWB-type [Ball, J.T., Woodrow, I.E., Berry, J.A., 1987. A model predicting stomatal conductance and its contribution to the control of photosynthesis under different environmental conditions. In: Biggens, J. (Ed.), Progress in Photosynthesis Research, vol. IV. Martinus Nijhoff, Dordrecht, pp. 221-224.] algorithm for calculating stomatal conductance (g(s)) at the leaf level have been parameterised for two crop and two tree species to test their use in regional scale ozone deposition modelling. The algorithms were tested against measured, site-specific data for durum wheat, grapevine, beech and birch of different European provenances. A direct comparison of both algorithms showed a similar performance in predicting hourly means and daily time-courses of g(s), whereas the multiplicative algorithm outperformed the BWB-type algorithm in modelling seasonal time-courses due to the inclusion of a phenology function. The re-parameterisation of the algorithms for local conditions in order to validate ozone deposition modelling on a European scale reveals the higher input requirements of the BWB-type algorithm as compared to the multiplicative algorithm because of the need of the former to model net photosynthesis (A(n)). 相似文献
982.
Hollander A Baijens I Ragas A Huijbregts M van de Meent D 《Environmental pollution (Barking, Essex : 1987)》2007,147(3):757-763
Multimedia mass balance models assume well-mixed homogeneous compartments. Particularly for soils, this does not correspond to reality, which results in potentially large uncertainties in estimates of transport fluxes from soils. A theoretically expected exponential decrease model of chemical concentrations with depth has been proposed, but hardly tested against empirical data. In this paper, we explored the correspondence between theoretically predicted soil concentration profiles and 84 field measured profiles. In most cases, chemical concentrations in soils appear to decline exponentially with depth, and values for the chemical specific soil penetration depth (d(p)) are predicted within one order of magnitude. Over all, the reliability of multimedia models will improve when they account for depth-dependent soil concentrations, so we recommend to take into account the described theoretical exponential decrease model of chemical concentrations with depth in chemical fate studies. In this model the d(p)-values should estimated be either based on local conditions or on a fixed d(p)-value, which we recommend to be 10cm for chemicals with a log K(ow)>3. 相似文献
983.
Element fluxes through European forest ecosystems and their relationships with stand and site characteristics 总被引:1,自引:0,他引:1
de Vries W van der Salm C Reinds GJ Erisman JW 《Environmental pollution (Barking, Essex : 1987)》2007,148(2):501-513
This paper describes a European wide assessment of element budgets, using available data on deposition, meteorology and soil solution chemistry at 121 Intensive Monitoring plots. Input fluxes from the atmosphere were derived from fortnightly or monthly measurements of bulk deposition and throughfall, corrected for canopy uptake. Element outputs from the forest ecosystem were derived by multiplying fortnightly or monthly measurements of the soil solution composition at the bottom of the root zone with simulated unsaturated soil water fluxes. Despite the uncertainties in the calculated budgets, the results indicate that: (i) SO4 is still the dominant source of actual soil acidification despite the generally lower input of S than N, due to the different behaviour of S (near tracer) and N (strong retention); (ii) base cation removal due to man-induced soil acidification is limited; and (iii) Al release is high in areas with high S inputs and low base status. 相似文献
984.
Carlos André Vaz Junior José Luiz de Medeiros Ofélia de Queiroz Fernandes Araújo 《Journal of Loss Prevention in the Process Industries》2010,23(3):462-475
This work presents a time series strategy for detection, location and quantification of leaks in large pipeline systems. The technology has two active components, which operate sequentially: the Detector and the Localizer. The Detector continuously screens real-time data, searching for any anomalies such as leaks, which are detected (or not) depending on their size and position. The Detector is based on auto-regressive multi-input/multi-output (MIMO) ARX predictors with one input filter. Subsequent to successful leak detection, the Localizer is launched to diagnose the leak via estimation of its parameters – diameter and location – using recorded data on a Search Time Window that includes information in the neighborhood of the instant of detection. The Localizer is also an ARX predictor, but with two input processors, the first is a filter for dynamic plant inputs and the second filter processes “parameter signals” of active leaks. The Localizer is developed beforehand via model identification with plant data under the action of known, artificially simulated, leaks. It is, therefore, able to recognize an active pattern of leak parameters, by maximizing the adherence of its predictions to data in the Search Time Window. The proposed detection and location methods were successfully tested in simulated leak scenarios for an industrial naphtha pipeline. 相似文献
985.
Many water-related problems are shared by most of the developing countries and the industrialized nations could be in position of offering aid in such problems. Water scarcity and access to safe water, water pollution, severe storms and floods, droughts, waterborne diseases and landslides and mud floods are the most commonly shared problems among developing nations. These problems were discussed in a workshop organized as part of the Fifth International Symposium on Environmental Hydraulics in 2008. The discussion included identification of actors both in the developing and developed nations (vgr. local and national governments, NGOs, universities, foundations and private and public research institutions), aid modalities such as education, technology transfer, technology development and direct investment as well as restrictions and barriers in the form of political and legal issues, economic limitations, cultural differences and geographic distances. Recommendations about how developed nations could help developing countries are issued. 相似文献
986.
987.
988.
989.