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71.
对几种大气环境预测方法的评估   总被引:5,自引:1,他引:5  
程水源 《环境科学》1991,12(3):85-88
本文根据石家庄市的常规气象资料和混合层高度,用不同的计算模式和计算方法对本市特征污染因子SO_4的长期平均浓度进行计算,把计算结果与实测浓度比较并进行误差分析,对每种计算方法进行评价,最后讨论了各种计算方法的特点及在城市大气环境预测中的实用性.  相似文献   
72.
瓦楞纸箱全生命周期环境影响评价研究   总被引:5,自引:8,他引:5       下载免费PDF全文
分析了瓦楞纸箱从原材料生产、产品加工到使用后的废物处置整个全生命周期的物耗、能耗及向环境中的排放;根据ISO14040系列标准制定的技术框架,建立了全生命周期评价(Life Cycle Assessment,LCA)模型,采用Eco-indicator 99方法,对瓦楞纸箱进行了整体和基于流程的全生命周期环境影响分析,得出其全生命周期和原料生产、产品加工、废物管理3个流程的主要环境影响类型和对应指标值,以及造成各流程主要环境影响类型的原因.为改善瓦楞纸箱的环境性能,针对其设计、生产加工、使用、废物处理等方面提出了改进建议;并对全生命周期环境影响评价研究中存在的不足进行了总结.   相似文献   
73.
Chang, Jian‐xia, Yi‐min Wang, and Qiang Huang, 2011. Water Dispatch Model for Middle Route of a South‐to‐North Water Transfer Project in China. Journal of the American Water Resources Association (JAWRA) 47(1):70‐80. DOI: 10.1111/j.1752‐1688.2010.00478.x Abstract: The objective of this paper is to present a simulation model to address the water dispatch problem of the south‐to‐north water transfer project for the Middle Route system in China. Reasonable rules and a system network structure are established. This model consists of five modules: (1) a data‐processing module, (2) an initial control module, (3) a multisource simulation dispatch module, (4) a system identification module, and (5) a revision module. Water allocated to each province and city along the route is obtained by simulation, and the long‐term operation results show that water supply reliabilities are significantly improved if the transferred water is jointly dispatched with the local water resources.  相似文献   
74.
ABSTRACT: Grain transportation is a major economic activity on the multiple use Snake-Columbia River System. Congress is currently considering increased transportation user fees aimed at recapturing federal expenditures for waterway operations and maintenance. Three types of fee structure and four levels of cost recovery are evaluated using a network program model. In each case traffic is diverted away from the river to other Puget Sound ports via truck and rail transport modes. Grain shippers in the region will be adversely affected by a higher transport bill. The Lower Columbia River port economic activities will be negatively affected; however, competitive uses of the river, recreation, and hydroelectric generation will likely benefit modestly.  相似文献   
75.
Many atmospheric dispersion models include only simpletreatment of surface features to estimate the wind profilesand stability parameters. Detailed characterisation of theland cover, particularly in large and complex urbanconurbations, is especially important, as the surfacefeatures can vary significantly over the area. This paperdiscusses the use of satellite land cover data to derivespatially resolved surface boundary layer (SBL) parameters.These parameters have been used in an air quality model,PEARL (Prediction Air Quality in Urban and RegionalLocations) for estimating monthly and annual COconcentrations. Land cover data, derived from LANDSATThematic Mapper Imagery, has been used to estimate SBLparameters (surface roughness length, albeedo, Bowen ratioand anthropogenic heat flux) for a study area of 10000km2 encompassing Greater London and the surroundingcounties. The SBL parameters have been assigned according tomajor land cover types for the whole area at a spatialresolution of 1 × 1 km. Predictions from two versions of the PEARL model (one with land cover data and one without)have been compared with each other and with measured data forannual and monthly CO concentrations from seven London airquality monitoring sites. This comparison shows thatdifferences between predicted and observed values can bereduced by up to a factor of three. The use of SBLparameters derived from land cover data also yields moredetailed predicted annual CO spatial patterns especially inand around suburban areas. The performance of both versionsof the model for monthly CO concentrations has been comparedwith a range of statistical measures. This comparisonconfirms that improved agreement is observed betweenmodelled and measured monthly CO concentrations when use ismade of spatially resolved SBL parameters.  相似文献   
76.
以苏通大桥斜拉桥的扁平钢箱梁结构为分析对象,采用子结构方法,将扁平钢箱梁结构的整体尺度动力特性和细节尺度构件损伤相互衔接,实现了超大跨斜拉桥的多尺度损伤分析。在此基础上,对模态曲率指标和模态应变能指标的损伤识别效果进行了对比分析。结果表明:采用子结构方法可以有效地实现钢箱梁局部构件损伤与整体结构响应的多尺度衔接,从而较真实地研究钢箱梁局部构件损伤对超大跨斜拉桥动力特性的影响;无噪声情况下,模态曲率指标能正确识别所有损伤工况,而模态应变能指标则对部分损伤工况的识别效果较差;模态应变能指标的抗噪声能力总体上优于模态曲率指标。  相似文献   
77.
Summary Present municipal waste management paradigms in Brazil do not allow for flexible approaches to solving an extremely dynamic problem. This paper discusses the basic flaws in present thinking models of residents and municipal administrators. Fundamental arguments presented on municipal solid waste relate to nomenclature, destinations, definitions, logistics, social dynamics, social assistance programs, education and employment philosophies. In each case, the consequences of the stalemate are explained in terms of the unsustainable situation of constantly growing landfills. In sequence, a proactive thinking model is presented and explained that has the potential of drastically reducing landfill size. It is called Municipal Transit Material Processing. The model has been tested successfully in small communities and is now available for scale-up. The landfill diversion achieved stands at 62% of household waste in comparison with 15% theoretically possible in Brazil with selective collection models. Although of necessity the arguments apply directly to Brazil, the basic ideas behind the reasoning may be extrapolated to other Southern countries. The following simple example will illustrate to the reader the type of paradigm inversion the paper proposes to convey. The classical political slogan in Brazil is “get children out of garbage dumps”. The inversion proposed and explained is “do away with garbage dumps”.  相似文献   
78.
基于对我国钢箱梁桥的钢箱梁病害调查,总结出我国钢箱粱典型病害的类型,分析各种钢箱梁典型病害产生的机理及导致其破坏的原因,提出了钢箱梁病害的日常检测与维护技术.针对钢箱梁的涂装劣化、钢材腐蚀、结构性损伤等病害,给出了日常检测与维护的主要项目,介绍了人工目视检测、超声波检测、磁粉检测及涡流检测等主要的检测方法的工作原理、优...  相似文献   
79.
Urine diversion (UD) has great potential to contribute to sustainably managing wastewater by separating urine at the source and recovering nutrients for reuse in agriculture. While factors enabling the UD technology in Sweden are thought to involve policies supporting nutrient recovery/reuse, on closer inspection, the variable success of UD systems has revealed that critical factors for success also relate to human-centred issues of social organisation, participation and incorporation of social knowledges of a variety of stakeholders into the decision-making process in which new technologies are trialled and adopted. Through the analytical lens of strategic niche management, we consider how early experimentation in UD has involved user participation and whether internal processes of learning, networking and visioning have been consciously considered and to what effect. As niche experiments are enabled/disabled not only by informal institutions such as values and social norms but also formal regulatory institutions, we have concurrently analysed the broader environment in which policies and institutions influence, to varying degrees, the uptake of UD.  相似文献   
80.
汽车内饰件的自然暴晒试验   总被引:2,自引:1,他引:1  
张华  高泽海 《环境技术》2009,27(3):10-13
本文主要阐述汽车内饰件自然暴晒试验方法:IP/DP箱试验和整车暴晒试验。汽车内部材料的耐用性是影响使用满意程度的极其重要的因素,所以汽车内饰材料需要一个模拟其在具体使用过程中的自然条件的试验,以便观察汽车内饰件在老化过程中的性能变化。  相似文献   
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