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601.
The chemical composition of the troposphere is controlled by various biogeochemical cycles that couple the atmosphere with the oceans, the solid Earth and the biosphere, and by atmospheric photochemical/chemical reactions. These cycles and reactions are discussed and a number of key questions concerning tropospheric composition and chemistry for the carbon, nitrogen, oxygen and sulfur species are identified. Next, we review various remote sensing techniques and instruments capable of measuring and monitoring tropospheric species from the ground, aircraft and space to address some of these key questions. We also consider future thrusts in remote sensing of the troposphere. 相似文献
602.
D. Kolbow H. Hikichi C. Tuthill C. W. Frank G. B. Wiersma A. B. Crockett R. D. Schonbrod US Epa 《Environmental monitoring and assessment》1986,6(3):231-257
Kinetic Analysis has been successful for metallic elements in relatively isolated areas. In this study it is applied to a complex organic compound in a geographical area with a large urban component. Ten media compartments are included, with man as the ultimate receptor. Field data were collected for only 6 of the media and were not used in the analysis but were compared to the calculated steady state concentrations. The greatest differences between calculated and observed values were 4.8-fold for soil and 5.4-fold for sediment. The field sampling regime for soils was biased towards areas of industrialization and probably explains the higher observed value. The lower observed value for sediment is likely due to unknown variables necessary for the estimation of the compartment size and/or the associated transfer rate constants. This study indicated that the Kinetic Analysis technique can be applied successfully to the pre-sampling estimation of the distribution of organic pollutants in environmental systems. 相似文献
603.
Brian A. Joyce Wesley W. Wallender Till Angermann Barry W. Wilson Ingeborg Werner Michael N. Oliver Frank G. Zalom John D. Henderson 《Journal of the American Water Resources Association》2004,40(4):1063-1070
ABSTRACT: Pesticide runoff from dormant sprayed orchards is a major water quality problem in California's Central Valley. During the past several years, diazinon levels in the Sacramento and San Joaquin Rivers have exceeded water quality criteria for aquatic organisms. Orchard water management, via post‐application irrigation, and infiltration enhancement, through the use of a vegetative ground cover, are management practices that are believed to reduce pesticide loading to surface waters. Field experiments were conducted in Davis, California, to measure the effectiveness of these management practices in reducing the toxicity of storm water runoff. Treatments using a vegetative ground cover significantly reduced peak concentrations and cumulative pesticide mass in runoff for first flush experiments compared with bare soil treatments. Post‐application irrigation was found to be an effective means of reducing peak concentrations and cumulative mass in runoff from bare soil treatments, but showed no significant effect on vegetated treatments. 相似文献
604.
605.
Frank Ackerman 《Local Environment》2000,5(2):223-229
Waste management has at least five types of impacts on climate change, attributable to: (1) landfill methane emissions; (2) reduction in industrial energy use and emissions due to recycling and waste reduction; (3) energy recovery from waste; (4) carbon sequestration in forests due to decreased demand for virgin paper; and (5) energy used in long-distance transport of waste: A recent USEPA study provides estimates of overall per-tonne greenhouse gas reductions due to recycling. Plausible calculations using these estimates suggest that countries such as the US or Australia could realise substantial greenhouse gas reductions through increased recycling, particularly of paper. 相似文献
606.
Against a background of inward investment into the region, the paper examines crucial issues relating to labour. It examines approaches to recruitment and the selection process. Skill shortages and strategies for overcoming the problem are analysed together with a consideration about management and managers. The paper concludes with a detailed assessment of policies relating to training. 相似文献
607.
本文系统分析和总结了美国在洪泛平原管理中的经验教训,研究了减灾措施、行为反应及国家长期减灾目标等方面的内容,从综合的角度提出了统一的国家减灾计划。 相似文献
608.
Frank A. Haight 《Journal of Safety Research》1983,14(1):1-12
This paper continues the discussion (Journal of Safety Research, 12(2), 50–58) of traffic safety problems in developing countries. The emphasis in this part is on the relationships between transportation and public health, with a number of specific suggestions for developing countries. 相似文献
609.
610.
Fereidoun Mobasheri Vikram S. Budhraja Frank E. Mack 《Journal of the American Water Resources Association》1971,7(4):823-830
ABSTRACT Mathematical models are formulated for selection of water resources projects to meet the future additional water requirements of a given region at the minimum present worth cost. The projects available are surface water reservoirs and desalination plants. The modles are used for selecting both the development sequence of projects and their optimum sizes. Decisions with regard to planning time horizon and discount rates are made outside of the mathematical model. The algorithm used for solving these models is an integer programming routine using the implicit enumeration technique. Some computational results are presented for a hypothetical case. 相似文献