全文获取类型
收费全文 | 141篇 |
免费 | 4篇 |
国内免费 | 1篇 |
专业分类
安全科学 | 10篇 |
环保管理 | 36篇 |
综合类 | 47篇 |
基础理论 | 20篇 |
污染及防治 | 18篇 |
评价与监测 | 6篇 |
社会与环境 | 9篇 |
出版年
2019年 | 5篇 |
2018年 | 2篇 |
2017年 | 4篇 |
2016年 | 3篇 |
2013年 | 3篇 |
2012年 | 2篇 |
2011年 | 6篇 |
2010年 | 3篇 |
2009年 | 2篇 |
2008年 | 3篇 |
2007年 | 5篇 |
2006年 | 3篇 |
2005年 | 9篇 |
2004年 | 3篇 |
2003年 | 7篇 |
2002年 | 6篇 |
2000年 | 3篇 |
1996年 | 2篇 |
1995年 | 2篇 |
1994年 | 4篇 |
1993年 | 2篇 |
1991年 | 4篇 |
1988年 | 2篇 |
1987年 | 7篇 |
1986年 | 1篇 |
1983年 | 1篇 |
1982年 | 2篇 |
1981年 | 3篇 |
1980年 | 1篇 |
1970年 | 2篇 |
1969年 | 2篇 |
1968年 | 6篇 |
1967年 | 4篇 |
1966年 | 2篇 |
1965年 | 1篇 |
1962年 | 1篇 |
1959年 | 1篇 |
1957年 | 2篇 |
1956年 | 1篇 |
1955年 | 3篇 |
1954年 | 4篇 |
1953年 | 2篇 |
1952年 | 1篇 |
1951年 | 1篇 |
1948年 | 1篇 |
1942年 | 2篇 |
1938年 | 1篇 |
1935年 | 1篇 |
1930年 | 1篇 |
1929年 | 1篇 |
排序方式: 共有146条查询结果,搜索用时 78 毫秒
81.
Achim Lohmeyer Wolfgang Baechlin Matthias Ketzel 《Environmental monitoring and assessment》2000,65(1-2):381-387
The draft of the German guideline to calculate automobile exhaust dispersion is explained. It contains a two-stage-system: For first quick estimates the guideline contains the simple models MLuS and STREET. In case these models are not applicable or their results shows concentration levels close to the air quality standards, the more complex models PROKAS_V and MISKAM are recommended. PROKAS_V is a Gaussian plume model, MISKAM is a 3-dimensional microscale non hydrostatic flow model for built-up areas with an Eulerian dispersion model. The guideline comprises cases in rural areas without or with few adjacent buildings as well as urban areas with buildings near the roads. The contribution gives information about the models, typical results and some of the problems showing up presently. 相似文献
82.
Matthias Ketzel Ruwim Berkowicz Achim Lohmeyer 《Environmental monitoring and assessment》2000,65(1-2):363-370
Numerical dispersion models developed and validated in different European countries were applied to data sets from wind tunnel and field measurements. The comparison includes the Danish Operational Street Pollution Model (OSPM) and the microscale flow and dispersion model MISKAM. The latter is recommended for application in built-up areas in the draft of the new German guideline VDI 3782/8. In a first step the models were applied to simplified street configurations. Different parameters as length and height of adjacent buildings and the angle of the incoming flow were varied. The results were compared to recent wind tunnel measurements. In a second step the models were applied to two extensively investigated field data sets from Jagtvej, Copenhagen and G ttinger Straße, Hannover. Intensified and more transparent and accessible validation procedures would be helpful for the thorough user. 相似文献
83.
Modelling heavy metal fluxes from traffic into the environment 总被引:1,自引:0,他引:1
A new method is presented which allows emissions of traffic into the environment to be described as a function of road distance. The method distinguishes different types of emissions (runoff, spray and drift), which are determined by measurements and mass balances of a specified road section. The measurement of two-dimensional pollutant concentrations in the road shoulder is an important part of the method. In a case study performed at Burgdorf, Switzerland, the method was applied to the determination of the spatial distribution of heavy metal emissions. The results show that between 36 and 65% of the heavy metals Cd, Cr, Cu, Pb and Zn are present in runoff and spray and between 35 and 64% are dispersed diffusely in the environment (defined as drift). The runoff infiltrates into the vegetated road shoulder up to a distance of approx. 1 m from the road. The distribution of spray shows a maximum at 1 m and decreases steadily up to a distance of 5 m. This information can serve as a basis for the quantitative evaluation of road-runoff treatment scenarios. Although the results of the Burgdorf study are case-specific, several general guidelines for the reduction of traffic-related emissions can be derived from it. 相似文献
84.
Ulloa Hugo N. Constantinescu George Chang Kyoungsik Horna-Munoz Daniel Sepúlveda Steiner Oscar Bouffard Damien Wüest Alfred 《Environmental Fluid Mechanics》2019,19(3):667-698
Environmental Fluid Mechanics - We report novel results of a numerical experiment designed for examining the basin-scale hydrodynamics that control the mass, momentum, and energy distribution in a... 相似文献
85.
Diversity-stability relationships have long been a topic of controversy in ecology, but one whose importance has been re-highlighted by increasing large-scale threats to global biodiversity. The ability of a community to recover from a perturbation (or resilience) is a common measure of stability that has received a large amount of theoretical attention. Yet, general expectations regarding diversity-resilience relations remain elusive. Moreover, the effects of productivity and its interaction with diversity on resilience are equally unclear. We examined the effects of species diversity, species composition, and productivity on population-and community-level resilience in experimental aquatic food webs composed of bacteria, algae, heterotrophic protozoa, and rotifers. Productivity manipulations were crossed with manipulations of the number of species and species compositions within trophic groups. Resilience was measured by perturbing communities with a nonselective, density-independent, mortality event and comparing responses over time between perturbed communities and controls. We found evidence that species diversity can enhance resilience at the community level (i.e., total community biomass), though this effect was more strongly expressed in low-productivity treatments. Diversity effects on resilience were driven by a sampling/selection effect, with resilient communities showing rapid response and dominance by a minority of species (primarily unicellular algae). In contrast, diversity had no effect on mean population-level resilience. Instead, the ability of a community's populations to recover from perturbations was dependent on species composition. We found no evidence of an effect of productivity, either positive or negative, on community- or population-level resilience. Our results indicate that the role of diversity as an insurer of stability may depend on the level of biological organization at which stability is measured, with effects emerging only when focusing on aggregate community properties. 相似文献
86.
Stef Bokhorst Stine Højlund Pedersen Ludovic Brucker Oleg Anisimov Jarle W. Bjerke Ross D. Brown Dorothee Ehrich Richard L. H. Essery Achim Heilig Susanne Ingvander Cecilia Johansson Margareta Johansson Ingibjörg Svala Jónsdóttir Niila Inga Kari Luojus Giovanni Macelloni Heather Mariash Donald McLennan Gunhild Ninis Rosqvist Atsushi Sato Hannele Savela Martin Schneebeli Aleksandr Sokolov Sergey A. Sokratov Silvia Terzago Dagrun Vikhamar-Schuler Scott Williamson Yubao Qiu Terry V. Callaghan 《Ambio》2016,45(5):516-537
87.
A project-based system for including farmers in the EU ETS 总被引:1,自引:0,他引:1
Farmers in the EU do not trade greenhouse gases under the Kyoto agreement. This is an empirical puzzle because agriculture is a significant contributor of greenhouse gases (GHG) in the EU and may harvest private net gains from trade. Furthermore, the US has strongly advocated land-use practices as 'the missing link' in past climate negotiations. We argue that farmers have relatively low marginal reduction costs and that consequences in terms of the effect on permit price and technology are overall positive in the EU Emission Trading System (ETS). Thus, we propose a project-based system for including the farming practices in the EU ETS that reduces the uncertainty from measuring emission reduction in this sector. The system encourages GHG reduction either by introducing a new and less polluting practice or by reducing the polluting activity. When doing so, farmers will receive GHG permits corresponding to the amount of reduction which can be stored for later use or sold in the EU ETS. 相似文献
88.
Burkart J Steiner G Reischl G Hitzenberger R 《Atmospheric environment (Oxford, England : 1994)》2011,45(32):5751-5759
During a total of 11 months, cloud condensation nuclei (CCN at super-saturation S 0.5%) and condensation nuclei (CN) concentrations were measured in the urban background aerosol of Vienna, Austria. For several months, number size distributions between 13.22?nm and 929?nm were also measured with a scanning mobility particle spectrometer (SMPS). Activation ratios (i.e. CCN/CN ratios) were calculated and apparent activation diameters obtained by integrating the SMPS size distributions. Variations in all CCN parameters (concentration, activation ratio, apparent activation diameter) are quite large on timescales of days to weeks. Passages of fronts influenced CCN parameters. Concentrations decreased with the passage of a front. No significant differences were found for fronts from different sectors (for Vienna mainly north to west and south to east). CCN concentrations at 0.5% S ranged from 160?cm(-3) to 3600?cm(-3) with a campaign average of 820?cm(-3). Activation ratios were quite low (0.02-0.47, average: 0.13) and comparable to activation ratios found in other polluted regions (e.g. Cubison et?al., 2008). Apparent activation diameters were found to be much larger (campaign average: 169?nm, range: (69-370) nm) than activation diameters for single-salt particles (around 50?nm depending on the salt). Contrary to CN concentrations, which are influenced by source patterns, CCN concentrations did not exhibit distinct diurnal patterns. Activation ratios showed diurnal variations counter-current to the variations of CN concentrations. 相似文献
89.
90.
Dorcas H. Franklin Jean L. Steiner Sara E. Duke Daniel N. Moriasi Patrick J. Starks 《Journal of the American Water Resources Association》2013,49(4):908-922
The Fort Cobb Watershed in Oklahoma has diverse biogeophysical settings and provides an opportunity to explore the association of water quality with a diverse set of landscapes during both wet (April 2007‐December 2009) and dry (January 2005‐March 2007) periods. The objective of this work was to identify spatial patterns in phosphorus (P) (soluble reactive P [SRP] and bioavailable P [BAP]) associated with landscape metrics for two distinct streamflow regimes. Spatial autocorrelation of P was evaluated using contiguous (side‐by‐side) and upstream (upstream:downstream) connectivity matrices. Biogeophysical metrics were compiled for each contributing area, and were partitioned based on association to P concentrations. Results for both SRP and BAP indicated that spatial autocorrelation was present (p < 0.05). There was more spatial autocorrelation and stream P concentrations were three to five times higher in the Wet phase than in the Dry phase (p < 0.05). Analysis with recursive partitioning resulted in higher R2 with spatial autocorrelation than without spatial autocorrelation and indicated that lateral metrics (topography, soil, geology, management) were better predictors for SRP than instream metrics. During Wet phase, lateral metrics indicative of rapid surface and subsurface water movement were associated with higher P stream concentrations. This research demonstrated that we can detect landscapes more vulnerable to P losses and/or contaminations in either drought or very wet periods. 相似文献