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301.
A GIS-based land evaluation model was developed to determine the food, feed, and fuelwood sufficiency of all districts in Nepal. Resource surpluses or deficits were calculated for each district for 1981, the year for which the national land resource data were available. Of the three resources, feed supplies were found to be the most critical. Feed deficits occurred in 57% of all districts in 1981, while food and fuelwood deficits occurred in less than 10% of all districts. Different scenarios were carried out for the year 2000 to estimate the magnitude of future resource deficits, assuming resource use and yields in Nepal remain constant in the face of growing population and livestock numbers. Linking resource data with spreadsheet and GIS systems provides a new way to understand and evaluate resources at the district and national levels. To more fully capture the usefulness of this approach, information on rates of change in productivity and land use is needed.  相似文献   
302.
In order to achieve sustainable utilization of natural resources, save energy and protect environment and ecosystem, it is important for a region or a nation to develop and implement a viable waste recycling model from both theoretical and practical point of view. Some packaging recycling models operated in developed countries are introduced in this article. Aluminium can recovery and recycling is emphasized. Cost effective, economic and environmental benefit of different models are compared and analyzed. The result shows that all recycling models have their characteristics due to the initial purpose of recovery and the situation of the implementing country. However, all the models contribute to the reduction of municipal solid waste disposal and resources conservation.  相似文献   
303.
Ensuring food security has been one of the major national priorities of Bangladesh since its independence in 1971. Now, this national priority is facing new challenges from the possible impacts of climate change in addition to the already existing threats from rapid population growth, declining availability of cultivable land, and inadequate access to water in the dry season. In this backdrop, this paper has examined the nature and magnitude of these threats for the benchmark years of 2030 and 2050. It has been shown that the overall impact of climate change on the production of food grains in Bangladesh would probably be small in 2030. This is due to the strong positive impact of CO2 fertilization that would compensate for the negative impacts of higher temperature and sea level rise. In 2050, the negative impacts of climate change might become noticeable: production of rice and wheat might drop by 8% and 32%, respectively. However, rice would be less affected by climate change compared to wheat, which is more sensitive to a change in temperature. Based on the population projections and analysis of future agronomic innovations, this study further shows that the availability of cultivable land alone would not be a constraint for achieving food self-sufficiency, provided that the productivity of rice and wheat grows at a rate of 10% or more per decade. However, the situation would be more critical in terms of water availability. If the dry season water availability does not decline from the 1990 level of about 100 Bm3, there would be just enough water in 2030 for meeting both the agricultural and nonagricultural needs. In 2050, the demand for irrigation water to maintain food self-sufficiency would be about 40% to 50% of the dry season water availability. Meeting such a high agricultural water demand might cause significant negative impacts on the domestic and commercial water supply, fisheries, ecosystems, navigation, and salinity management.  相似文献   
304.
Synthetic polymers are important to the packaging industry but their use raises aesthetic and environmental concerns, particularly with regard to solid waste accumulation problems and the threat to wildlife. Some concerns are addressed by attention to problems associated with source reduction, incineration, recycling and landfill. Others are addressed by the development of new biodegradable polymers either alone or in blends. Materials used for biodegradable polymers include various forms of starch and products derived from it, biopolyesters and some synthetic polymers. Starch is rapidly metabolised and is an excellent base material for polymer blends or for infill of more environmentally inert polymers where it is metabolised to leave less residual polymer on biodegradation. This should help to improve the environmental impact of waste disposal. A number of standard methods have been developed to estimate the extent of biodegradability of polymers under various conditions and with a variety of organisms. They tend to be used mainly in the countries where they were developed but there is much overlap between the standards of different countries and wide scope for development of consistent and international standards.  相似文献   
305.
我国食品安全现状分析及其对策   总被引:17,自引:2,他引:17  
食品安全直接关系到人民的生活和公众的健康 ,是当今世界最为关注的严重公害之一 ,食品安全带来的诸多问题已受到世界各国政府和人民的广泛重视。笔者概要地分析了我国食品安全现状 ,指出了我国食品存在的主要安全问题 ,提出了改善我国食品安全现状的有关对策  相似文献   
306.
Fleurett A 《Disasters》1986,10(3):224-229
Drought is a frequent occurrence in contemporary sub-Saharan Africa, and the existence of periodic drought can be documented over hundreds of years. As a consequence of the routine rainfall shortages that affect them, agricultural and pastoral societies have developed a number of social institutions and mechanisms for bridging temporary food production shortfalls caused by drought. Drawing on the literature and field data from southeastern Kenya, this paper discusses a number of regular indigenous responses to short-term drought in sub-Saharan Africa. Changes in these patterns in the present day are also discussed. It is concluded that market-based responses are now the most important strategies, but that traditional institutions remain significant and contribute to the viability of drought-affected societies.  相似文献   
307.
/ Data were collected from 245 farmers within the Darby Creek hydrologic unit in central Ohio to assess perceptions of risk associated with use of farm chemicals. Farmers were asked to evaluate the level of risk associated with use of agricultural chemicals for water quality, food safety, food quality, health of applicator, health of farm animals, wildlife, beneficial plants, beneficial insects, and human health. Study findings revealed that respondents perceived use of farm chemicals posed little or no threat to any of the assessed items. A composite index was formulated from the responses to the nine items and was titled Perceived Risk. Variance in the Perceived Risk index was regressed against social learning variables. The findings revealed that approximately 32% of the variance was explained by the predictive variables included in the model. It was concluded that the theoretical perspective was somewhat useful for understanding perceptions held about agricultural chemical use at the farm level. The findings are discussed in the context of future conservation and educational-information programs within the study region.KEY WORDS: Risk perception; Risk assessment; Groundwater; Pesticide contamination; Food safety; Environmental quality  相似文献   
308.
后勤车辆装备封存管理与实施研究   总被引:3,自引:0,他引:3  
装备封存具有显著的军事经济效益,是装备管理的重要内容。根据我军后勤装备建设的特点和新时期军事斗争准备要求,对装备封存管理理论与技术方法进行了探讨。针对封存标准化、规范化管理中的不足,提出了4条封存原则。研究了封存准备、封存实施和封存检查等内容。  相似文献   
309.
膜分离工艺在食品工业清洁生产中的应用   总被引:7,自引:0,他引:7  
结合典型例子介绍了膜分离工艺在食品工业清洁生产中的应用,论述了膜技术在食品工业中应用的现状和发展情况。  相似文献   
310.
卷烟包装材料及滤嘴的生物降解性能研究   总被引:1,自引:0,他引:1  
本研究以目前几种常见的卷烟包装用商标纸、卡纸、铝箔内衬纸、透明塑料薄膜以及卷烟滤嘴为实验材料,采用ATSMD-5338标准方法,进行了为期25天实验。结果表明商标纸、铝箔纸内衬纸和卡纸的生物降解性能比较好,而滤嘴和透明塑料薄膜的生物降解性能比较差。今后研究开发可降解卷烟包装材料应该把重点放在滤嘴和透明塑料薄膜上面。  相似文献   
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