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   31篇
  免费   0篇
安全科学   2篇
环保管理   12篇
综合类   5篇
基础理论   4篇
污染及防治   5篇
评价与监测   1篇
社会与环境   2篇
  2023年   1篇
  2022年   1篇
  2021年   2篇
  2019年   1篇
  2018年   2篇
  2013年   4篇
  2009年   1篇
  2008年   2篇
  2005年   1篇
  1995年   1篇
  1994年   1篇
  1993年   1篇
  1992年   1篇
  1988年   3篇
  1987年   1篇
  1986年   2篇
  1981年   1篇
  1980年   1篇
  1979年   2篇
  1976年   1篇
  1973年   1篇
排序方式: 共有31条查询结果,搜索用时 15 毫秒
1.
ABSTRACT: The domestic sewage of the city of Beer-Sheva, Israel, which is located in an arid region, is treated in a series of facultative ponds. The treated effluent is stored temporarily in an open surface earthen reservoir (about 0.5 ± 106 m3 in volume) and then used for irrigation. The effluent is applied via sprinkler and trickle irrigation systems. The main crops irrigated are cotton, wheat, alfalfa, and corn. Total cotton yield is over 5500 kg/ha, and the wheat grain yield is over 7500 kg/ha. The amount of effluent applied is about 6500 m3/ha for cotton (including preplant irrigation), and the wheat receives about 4500 m3/ha via irrigation and an additional 2000 m3/ha from precipitation. Due to the nutrient content in the effluent, the above yields are obtained without any additional fertilization.  相似文献   
2.
3.
The study contains the methodology of finding the optimal time to start the operation of a desalting plant or any other non conventional source of water for agricultural use in Israel. The essence of the methodology is the moving equilibrium price and quantity of agricultural products. The market of agricultural products is represented by a single demand curve and a supply curve which is derived from the agricultural sector production function. Both the demand for and the supply of agricultural products functions are shifting over time. The marginal value product of water is the critical value that determines the optimal time of a desalting plant. The study is static in the sense that dynamic aspects per se are not dealt with-e.g. learning by doing of building and operating desalting plants. The empirical results although used for illustrative purposes can be used as reference points for other detailed and more ‘exact’ studies on water desalination.  相似文献   
4.
5.
Emission control policies under uncertainty   总被引:1,自引:0,他引:1  
The paper deals with the problem of optimal environmental policy under uncertainty. Usually, when an environmental policy is considered, only the expected values of the parameters of the marginal benefit and marginal cost functions associated with the policy are known. Thus a relevant question is: In the presence of uncertainty, what is the optimal policy mean for achieving the environmental objective? The study addresses itself to the specific objective of improving air quality although the analysis is generally applicable. The policy means are emission taxes and emission quotas. It is shown that under uncertainty neither of these means is generally optimal, and that specific parameter values of the costs and benefits relations and their distributions determine the optimal policy for each situation.  相似文献   
6.
Process hazards review (PHR) techniques have generally been applied by large, sophisticated companies in the nuclear, aerospace, and chemical process industries. There remains, however, a large population of smaller distributors and consumers of hazardous materials which could benefit equally from the application of PHR. These consumers unfortunately are generally less sophisticated and individually lack the necessary resources required to apply such state-of-the-art safety techniques.

Where common processes can be identified, it is possible to conduct a more generic PHR that will provide a sound technical basis for recognizing and preventing the development of hazards wherever these processes are used. Some facility-specific issues will always need to be considered, but the existence of the generic PHR should make the conduct of a PHR by each facility considerably easier and less costly.

Researchers from the National Institute for Occupational Safety and Health (NIOSH) contracted with DNV Technica Inc. to lead a hazard and operability study (HAZOP) of agricultural handling of anhydrous ammonia, from the receipt of ammonia at the retail distribution centre to the application of the ammonia by farmers to the fields. The multidisciplinary HAZOP team consisted of representatives from NIOSH, an agricultural chemical trade association, an ammonia producer, state ammonia facility inspectors, a retail distributor, and an equipment manufacturer. Several participants were part-time farmers with ammonia application experience.

Some specific aspects of applying the HAZOP technique in the context of this study, the findings obtained, and the plans to disseminate the important safety information developed during the course of the PHR are discussed. Finally, it is suggested that this approach could prove to be a useful addition to the product stewardship activities of chemical producers.  相似文献   

7.
Seasonal changes in the microbial communities of the New Calabar Riverwater have been investigated. Analyses of the BOD, pH, salinity, oil and grease levels of effluents of industries sited along the river were also conducted. High hydrocarbon-utilizing microbial populations were found. The percentage of hydrocarbon-utilizing heterotrophic bacteria ranged between 0–98% and 0–68% in the rainy and dry months, respectively. Counts of hydrocarbon-utilizing actinomycetes in the rainy months ranged between 0–95% and 2–55% in the dry months. The hydrocarbon-utilizing yeast population ranged between 1–95% and 2–85% for the rainy and dry months, respectively. Rainy month values for hydrocarbon-utilizing mould population ranged from 0–17% while dry month values ranged from 0–47%. The hydrocarbon-utilizing cyanobacterial population ranged between 0–95% and 0–33% in the rainy and dry months, respectively. Our results suggest that the heterotrophic bacterial and cyanobacterial populations are higher in the rainy months than in the dry months. However, the hydrocarbon-utilizing yeast, mould and actinomycete populations did not show seasonal variation.  相似文献   
8.
ABSTRACT: Electric generation facility water requirement will increase substantially in the future in the Western United States because new power plants are to be constructed at inland sites rather than on the coast. At the inland locations, power plants will have to compete with agriculture and public users for fresh water supplies, and will be constrained by environmental legislation to dispose of cooling waste water in lined evaporation ponds. The various options for power plant cooling are analyzed in respect to cost, water consumption, and environmental hazard, and also in respect to their compatibility with existing state and federal regulations. Several proposals for balancing the water requirements of various users in water-scarce areas are reviewed and criticized.  相似文献   
9.
We investigated the contribution of different screening criteria to the prenatal detection of Down syndrome (DS) as well as other chromosomal anomalies in the Jewish population in Israel during 1990 and 1992. There was a significant decrease (P<0·03) in the incidence of DS live-births during 1992 (40:78 442) compared with 1990 (69:73 751) which paralleled a marked increase in total prenatal testing and in DS cases detected prenatally. Private laboratories, which perform amniocenteses mostly for women with a low risk of DS and without genetic counselling, had a significantly lower detection rate (1:917) compared with that of the genetic institutes, which following genetic counselling test both women ≥ 37 years of age (1:91) and women younger than 37 years (1:113). The detection of chromosomal anomalies other than DS was less affected by the reason for amniocentesis. Amniocentesis indicated by maternal serum marker screening of women younger than 37 years identified a greater number of chromosomal anomalies other than DS than amniocentesis based on age (≥37 years) alone (111:9604 versus 94:9810; P<0·06). Prenatal detection of DS is most effective when the indication for amniocentesis follows genetic counselling. The increasing use of maternal serum marker screening leads to a significant improvement in the positive detection rate of chromosomal anomalies other than DS in young women.  相似文献   
10.
This report contains a short theoretical proof for the non-optima lity of a uniform emission tax. A method recently suggested for finding the optimal level of a uniform tax is criticized. An alternative tax system that could be either uniform or non-uniform that is gradually increasing over time is suggested instead. The paper is aimed at stimulating discussions on theoretical and empirical grounds on the feasibility and efficiency of the suggested tax.  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