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341.
In the recent years a group of contaminants, known collectively as emerging contaminants (ECs), have attracted considerable attention due to their widespread in the environment, and lack of knowledge on their impacts on ecosystem and human health. This review gives an overview on the sources, impacts, and conventional treatment technologies of ECs and an in-depth review of the literature on the state-of-the-art treatment technologies and their performance in the removal of ECs from water sources and drinking water. A careful statistical analysis of the number of publications on the different treatment technologies of ECs was performed to identify the hot spots in this research area. Conventional treatment technologies are not able to remove ECs sufficiently. The discharge of raw or partially treated wastewater is the main source of ECs in the environment. The research in recent years is focusing on using advanced treatment process (AOPs), followed by adsorption and membrane technologies. From a technical point of view, AOPs surpass other treatment technologies as they can completely eradicate ECs without the generation of side products. Developing efficient, green, and cost-effective materials to be used as adsorbents, photocatalysts, membranes, or membrane fillers, is one of the main research trends nowadays. Combined AOPs based on exploiting solar light, ultrasound and electrochemistry are gaining growing interest and show high potential for the treatment of ECs. 相似文献
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F Desiato D Anfossi S Trini Castelli E Ferrero G Tinarelli 《Atmospheric environment (Oxford, England : 1994)》1998,32(24):274
Two Lagrangian particle models, APOLLO and MILORD, were used to simulate the first ETEX experiment. The role played by wind field, mixing height h and horizontal diffusivity KH appeared to be the most important aspects to be studied. The sensitivity to the accuracy of the input advection field was studied through the application of APOLLO using different ECMWF data sets differing in space and time resolution and in being forecasted or analysed, corresponding to the real-time, emergency-like condition, and to the a posteriori benchmark simulation. The role of h and KH was investigated by running both APOLLO and MILORD with different parameterisations, and comparing the model results between them and with the available observations.The model evaluation was carried out through a set of statistical indexes computed on three hourly average concentrations paired in space and time and time-integrated concentrations. It was found that the quality of the input wind field plays a major role in predicting with sufficient accuracy the plume position and extension after the first 24 h from the beginning of the release. The best-model results are obtained with large values of KH (in the range of 2.5×104–4.5×104 m2 s-1), which confirms the need to enhance the horizontal diffusion, in order to include the advection fluctuations unresolved by large-scale meteorological fields. A fixed value of h in the range 1000–1500 m seems to be more efficient than space and time variable h computed with standard algorithms. A reasonable explanation for this result is given, based on the consideration that in the long range, particles diffuse also in the residual layer above the stable nocturnal boundary layer. 相似文献
345.
为预防铁路危险品运输系统事故的发生,采用STAMP-ISM模型分析铁路危险品运输系统风险-事故。首先,利用STAMP模型详细分析事故,得到控制结构的相关安全约束、不充分控制行为及产生原因,以及系统的安全动态变化;其次,采用ISM分析事故致因因素之间的关联关系并划分层级;最后,基于STAMP和ISM分析结果提出系统改进方案。以我国一起匿名夹带事故为背景进行案例研究,结果表明,ISM模型的加入可深入挖掘事故因素间的相互关系,为事故致因因素重要度划分层级,分析结果及建议更具针对性。 相似文献
346.
Kenneth W. Potter T. Matthew Boyington 《Journal of the American Water Resources Association》2020,56(2):323-332
River floodplains provide critical habitat for a wide range of animal and plant species and reduce phosphorus and nitrogen loads in streams. It has been observed that baseflow‐dominated streams flowing through wetlands are commonly at or near bankfull and overflow their banks much more frequently than other streams. However, there is very little published quantitative support for this observation. The study focuses on a 1‐km reach of Black Earth Creek, a stream in the Midwestern United States (U.S.). We used one‐dimensional hydraulic modeling to estimate bankfull discharge at evenly spaced stream cross sections, and two‐dimensional modeling to quantitate the extent of wetland inundation as a function of discharge. We then used historical streamflow data from two U.S. Geological Survey gaging stations to quantitate the frequency of wetland inundation. For the with‐sediment case, the frequency of overbank conditions at the 38 cross sections in the wetland ranged from 3 to 85 days per year and averaged 43 days per year. Ten percent of the wetland was inundated for an average of 35 days per year. For the without‐sediment case, the frequency of overbank conditions ranged from 2.6 to 48 days per year and averaged 14 days per year. Also, 10% of the wetland was inundated for an average of 25 days per year. These unusually high rates of floodplain inundation are likely due in part to the very low stream gradient and shallow depths of overbank flow. 相似文献
347.
This paper is concerned with the cost efficiency in achieving the Swedish national air quality objectives under uncertainty.
To realize an ecologically sustainable society, the parliament has approved a set of interim and long-term pollution reduction
targets. However, there are considerable quantification uncertainties on the effectiveness of the proposed pollution reduction
measures. In this paper, we develop a multivariate stochastic control framework to deal with the cost efficiency problem with
multiple pollutants. Based on the cost and technological data collected by several national authorities, we explore the implications
of alternative probabilistic constraints. It is found that a composite probabilistic constraint induces considerably lower
abatement cost than separable probabilistic restrictions. The trend is reinforced by the presence of positive correlations
between reductions in the multiple pollutants.
相似文献
Chuan-Zhong LiEmail: |
348.
Factors controlling the salinity in groundwater in parts of Guntur district, Andhra Pradesh, India 总被引:1,自引:0,他引:1
Subba Rao N 《Environmental monitoring and assessment》2008,138(1-3):327-341
Groundwater chemistry has been studied to examine the associated hydrogeochemical processes operating for the development
of salinity in the groundwater in parts of Guntur district, Andhra Pradesh, India. The study area is underlain by charnockites
and granitic gneisses associated with schists of the Precambrian Eastern Ghats. Groundwater is the main resource for irrigation
besides drinking. Chemical parameters, pH, EC, TDS, Ca2+, Mg2+, Na+, K+, , , Cl−, , , F− and SiO2, are taken into account. Groundwater is of brackish type. Na+−Cl− facies dominates the groundwater. Examination of compositional relations and mineral saturation states shows that the ion
exchange of Ca2+ for adsorbed Na+, evapotranspiration, dissolution of soil salts, dissolution of NaCl and CaSO4, and precipitation of CaCO3 are the dominant hydrogeochemical processes associated with the groundwater composition in the area. Evapotranspiration causes
accumulation of salts in the soil/weathered zone. These salts reach the water table by leaching through infiltrating recharge
water. A positive relation between depth to water table and TDS with season supports this inference. The effects of human
activities, such as intensive and long-term irrigation, irrigation-return-flow, application of unlimited agricultural fertilizers
and recycling of saline groundwater, act to further increase the salinity in the groundwater. Therefore, the groundwater quality
increases towards the flow path, while the post-monsoon groundwater shows higher concentrations of TDS, Na+, Mg2+, Cl−, , , F− and SiO2 ions. The study could help to understand the hydrogeochemical characteristics of the aquifer system for taking effective
management measures to mitigate the inferior groundwater quality for sustainable development. 相似文献
349.
In this study, an integrated solid waste management system based on inexact fuzzy-stochastic mixed integer linear programming (IFSMILP) has been applied to the long-term planning of waste management activities in the City of Regina. The model can effectively reflect dynamic, interactive, and uncertain characteristics of the solid waste management system in the city. The results have provided useful answers for the following questions: “What waste reduction goals are desired if the existing landfill's life is prolonged for 15 years?”, “What should be the waste flow allocation pattern in the city?”, “What should be done if the waste generation rate increases rapidly, while the relevant handling capacity is limited?”, and “What level of reliability will we have given the suggested waste management plan?” 相似文献
350.