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   92篇
  免费   1篇
安全科学   9篇
废物处理   1篇
环保管理   9篇
综合类   8篇
基础理论   24篇
污染及防治   34篇
评价与监测   5篇
社会与环境   3篇
  2022年   4篇
  2021年   2篇
  2020年   1篇
  2018年   2篇
  2017年   2篇
  2016年   5篇
  2014年   2篇
  2013年   7篇
  2012年   4篇
  2011年   8篇
  2010年   4篇
  2009年   3篇
  2008年   6篇
  2007年   9篇
  2006年   3篇
  2005年   7篇
  2004年   3篇
  2003年   5篇
  2002年   3篇
  2001年   2篇
  2000年   1篇
  1999年   3篇
  1997年   1篇
  1996年   1篇
  1991年   1篇
  1990年   1篇
  1985年   2篇
  1984年   1篇
排序方式: 共有93条查询结果,搜索用时 312 毫秒
41.
Tail autotomy in lizards is an adaptive strategy that has evolved to reduce the risk of predation. Since tail loss reduces body mass and moving ability—which in turn are expected to influence thermal balance—there is potential for a trade-off between tail autotomy and thermoregulation. To test this hypothesis, we studied a common lizard (Zootoca vivipara) population at high latitude, inhabiting a high-cost thermal environment. Z. vivipara is a small, non-territorial lizard known as a very accurate thermoregulator. We made two predictions: (1) the reduced body weight due to tail loss results in faster heating rate (a benefit), and (2) the reduction in locomotor ability after tail loss induces a shift to the use of thermally poorer microhabitats (a cost), thus decreasing the field body temperatures of active lizards. We did not find any effect of tail loss on heating rate in laboratory experiments conducted under different thermal conditions. Likewise, no significant relationship between tail condition and field body temperatures, or between tail condition and thermal microhabitat use, were detected. Thus, our results suggest that tail autotomy does not influence the accuracy of thermoregulation in small-bodied lizards.Electronic Supplementary Material  Supplementary material is available in the online version of this article at  相似文献   
42.
Volatile organic compounds containing reduced sulphur such as thiols and thioethers are released mostly from biological activities and a number of manufacturing processes, such as papermaking and petroleum refining. Environmentally benign and cost-effective air pollution control technology for reduced sulphur compounds is still a topic of research, e.g., in pulp and paper industry. Due to its advantages, photocatalytic oxidation over titanium dioxide presents a potential alternative for the air treatment strategies. The temperature influence on the reaction pathway and kinetics of gas-phase photocatalytic oxidation and thermal catalytic decomposition of ethanethiol over Degussa P25 TiO2 was established by a continuous flow method in a simple tubular reactor at temperatures from 373 to 453 K. Kinetic parameters for ethanethiol were: adsorption enthalpy −45 kJ mol−1 and activation energy 42 kJ mol−1. Sulphur dioxide, carbon monoxide, carbon dioxide, acetic acid and water were identified as by-products.  相似文献   
43.
Summary Coexistence of defended and undefended plants may be maintained by herbivory. In the present paper this phenomenon is analyzed by means of evolutionary game theory. The plants in the model play either a defensive or a non-defensive strategy and they interact indirectly: when a plant is grazed its competitive ability decreases, because of this a neighboring plant makes a profit. The solution to the game leads to three qualitatively different cases depending on whether the profit is equal for the two strategies, defended and undefended, or if the profit is higher for one type than for the other. When the results are applied to intea-specific interactions, the model predicts that polymorphic populations should be expected only under certain specific conditions. When the results are applied to inter-specific interactions, the model predicts either stable coexistence, i.e., increased diversity, or a paradoxical situation without increased diversity.Offprint requests to: M. Augner  相似文献   
44.
Environmental Science and Pollution Research - For a recirculating aquaculture system (RAS), a passive water treatment system was designed for efficient discharge nutrient removal and water reuse...  相似文献   
45.
Co-operation between different parties and effective safety management play an important role in ensuring safety in multiemployer worksites. This article reviews safety co-operation and factors complicating safety management in Finnish multiemployer manufacturing worksites. The paper focuses on the service providers’ opinions; however, a comparison of the customers’ views is also presented. The results show that safety-related co-operation between providers and customers is generally considered as successful but strongly dependent on the partner. Safety co-operation is provided through, e.g., training, orientation and risk analysis. Problems encountered include ensuring adequate communication, identifying hazards, co-ordinating work tasks and determining responsibilities. The providers and the customers encounter similar safety management problems. The results presented in this article can help companies to focus their efforts on the most problematic points of safety management and to avoid common pitfalls.  相似文献   
46.
Environmental Fluid Mechanics - Shrubby and woody vegetation growing on floodplains profoundly influences hydrodynamic and transport processes in riverine systems. Existing hydrodynamic research is...  相似文献   
47.
Methane oxidation was studied at a closed boreal landfill (area 3.9 ha, amount of deposited waste 200,000 tonnes) equipped with a passive gas collection and distribution system and a methane oxidative top soil cover integrated in a European Union landfill directive-compliant, multilayer final cover. Gas wells and distribution pipes with valves were installed to direct landfill gas through the water impermeable layer into the top soil cover. Mean methane emissions at the 25 measuring points at four measurement times (October 2005–June 2006) were 0.86–6.2 m3 ha?1 h?1. Conservative estimates indicated that at least 25% of the methane flux entering the soil cover at the measuring points was oxidized in October and February, and at least 46% in June. At each measurement time, 1–3 points showed significantly higher methane fluxes into the soil cover (20–135 m3 ha?1 h?1) and methane emissions (6–135 m3 ha?1 h?1) compared to the other points (<20 m3 ha?1 h?1 and <10 m3 ha?1 h?1, respectively). These points of methane overload had a high impact on the mean methane oxidation at the measuring points, resulting in zero mean oxidation at one measurement time (November). However, it was found that by adjusting the valves in the gas distribution pipes the occurrence of methane overload can be to some extent moderated which may increase methane oxidation. Overall, the investigated landfill gas treatment concept may be a feasible option for reducing methane emissions at landfills where a water impermeable cover system is used.  相似文献   
48.
While the self-heating and spontaneous combustion of coal is a known challenge at coal mines and storage sites, there are known methods for mitigating this challenge for typical open stockpile storage. However, closing the storage will reduce access for corrective action, and it is then important to manage the storage and its transport system with added attention without unduly adding cost or hindering availability. This paper aims to discuss the risk, prevention and extinguishing of fires in closed coal storage facilities, particularly in light of the experience with the Salmisaari underground rock storage facility in Finland. The observed autoignition events have indicated an array of contributing factors, some of which are unique to underground silo storage facilities. On the other hand, many features of the storage facilities can be compared with other extant closed storage systems. The factors affecting fire risk are described and the associated fault and event trees are outlined for autoignition at underground storage. Drawing upon the experiences with past events of self-heating and spontaneous combustion, recommendations are given on cost-effective preventive, corrective and other mitigating action for minimising fire risk and promoting storage availability.  相似文献   
49.

Background

This paper aims to investigate the correlations between the concentrations of nine heavy metals in moss and atmospheric deposition within ecological land classes covering Europe. Additionally, it is examined to what extent the statistical relations are affected by the land use around the moss sampling sites. Based on moss data collected in 2010/2011 throughout Europe and data on total atmospheric deposition modelled by two chemical transport models (EMEP MSC-E, LOTOS-EUROS), correlation coefficients between concentrations of heavy metals in moss and in modelled atmospheric deposition were specified for spatial subsamples defined by ecological land classes of Europe (ELCE) as a spatial reference system. Linear discriminant analysis (LDA) and logistic regression (LR) were then used to separate moss sampling sites regarding their contribution to the strength of correlation considering the areal percentage of urban, agricultural and forestry land use around the sampling location. After verification LDA models by LR, LDA models were used to transform spatial information on the land use to maps of potential correlation levels, applicable for future network planning in the European Moss Survey.

Results

Correlations between concentrations of heavy metals in moss and in modelled atmospheric deposition were found to be specific for elements and ELCE units. Land use around the sampling sites mainly influences the correlation level. Small radiuses around the sampling sites examined (5 km) are more relevant for Cd, Cu, Ni, and Zn, while the areal percentage of urban and agricultural land use within large radiuses (75–100 km) is more relevant for As, Cr, Hg, Pb, and V. Most valid LDA models pattern with error rates of <?40% were found for As, Cr, Cu, Hg, Pb, and V. Land use-dependent predictions of spatial patterns split up Europe into investigation areas revealing potentially high (=?above-average) or low (=?below-average) correlation coefficients.

Conclusions

LDA is an eligible method identifying and ranking boundary conditions of correlations between atmospheric deposition and respective concentrations of heavy metals in moss and related mapping considering the influence of the land use around moss sampling sites.
  相似文献   
50.
A milestone in the field of European water protection policy is the European Union’s Water Framework Directive (WFD), which came into force in December 2000 and which integrates the management of European waters in many ways. In this study, we start by focusing on management issues connected to the implementation of the WFD and pose a question: “what type of models would be the most suitable for use in the context of the WFD?” With this question in mind, we aim to establish a set of operational and functional selection criteria for (computer) models whose application is intended to support decision-making related to a particular water management issue. These so-called “benchmark criteria” should help water managers and other model users in choosing appropriate models, e.g., for the WFD implementation purposes. We first describe models and their use in general and then propose an approach for setting the benchmark criteria for models, basing it on the concept of uncertainty management, while keeping firmly in mind the important role of citizens and citizen organizations in water management. The suggested benchmark criteria are in the form of 14 questions through which each model can be evaluated. Finally, the process for testing and refining the benchmark criteria is highlighted.  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