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451.
452.
Douglas M. Knudson 《Journal of the American Water Resources Association》1979,15(3):718-727
ABSTRACT: Efforts to protect free flowing streams of state significance have met with limited success. Some states established large numbers of “instant” scenic rivers through legislation, then have worked out procedures to add new streams. Other have inadequate current funding and staff to implement the law. The chief barriers to growth of the systems are:
- lack of program staffing and funding and support in some states,
- slowness of the study and planning process,
- landowner uncertainties about the effects on their property and rights, and
- legal complexities.
453.
E. L. Michalson J. R. Hamilton 《Journal of the American Water Resources Association》1975,11(6):1149-1156
ABSTRACT: A methodology is developed for examining the environmental and developmental conflicts inherent in the classification process of a wild river. The Salmon River in Idaho is used as an example of the methodology. The steps were: 1. a resource inventory, 2. an evaluation methodology, and 3. an economic comparison of resource use tradeoffs. Alternatives for the Salmon were examined, following generally the procedures outlined in the United States Water Resources Council's Establishment of Principles and Standards for Planning Water and Related Land Resources Final comparisons showed that hydroelectric development had greater net benefits than outdoor recreation at up to a three percent recreation growth rate. When recreation use grew at a faster rate, recreation had a considerable margin of net benefits in its favor. 相似文献
454.
目前所采取的传统河流治理方法耗资巨大,污染容易复发,是典型的资金推动型治理措施,而直接净化技术是河流水质治理领域中非常具有生命力的技术,对中国的河流治理迅速走出和摆脱高投入低效益的困境具有重要的意义. 相似文献
455.
保留怒江“原生态河流”质疑 总被引:1,自引:0,他引:1
怒江河谷区的"原生态"特征早已消失,当今急需为当地少数民族找到尽快脱贫的生产方式。建立水电站,同时做好生态环境保护,是一条能使当地环境与经济协调发展的道路。从国家能源战略的需求出发,也必须开发怒江水电资源。建议尽快开展怒江流域环保规划,实施水电开发的生态建设。 相似文献
456.
457.
陈菊芬 《城市环境与城市生态》2002,15(2):32-33
简要介绍了玉环县五大河流环境质量现状,分析了造成了五大河流受污染的原因,并从环保的角度提出了建议项目指导性意见,以及分流域提出了五大河流的污染防治对策。 相似文献
458.
459.
Robert J. Gilliom Daphne G. Clifton 《Journal of the American Water Resources Association》1990,26(1):11-24
ABSTRACT: Bed sediments of the San Joaquin River and its tributaries were sampled during October 7–11, 1985, and analyzed for organochiorine pesticide residues in order to determine their areal distribution and to evaluate and prioritize needs for further study. Residues of DDD, DDE, DDT, and dieldrin are widespread in the fine-grained bed sediments of the San Joaquin River and its tributaries despite little or no use of these pesticides for more than 15 years. The San Joaquin River has among the highest bed-sediment concentrations of DDD, DDE, DDT, and dieldrin residues of major rivers in the United States. Concentrations of all four pesticides were correlated with each other and with the amount of organic carbon and fine-grained particles in the bed sediments. The highest concentrations occurred in bed sediments of westside tributary streams. Potential tributary loads of DDD, DDE, DDT, and dieldrin to the San Joaquin River were computed from bed-sediment concentrations and data on streamfiow and suspended-sediment concentration in order to identify the general magnitude of differences between streams and to determine study priorities. The estimated loads indicate that the most important sources of residues during the study period were Salt Slough because of a high load of fine sediment, and Newman Wasteway, Orestimba Creek, and Hospital Creek because of high bed-sediment concentrations. Generally, the highest estimated loads of DDD, DDE, DDT, and dieldrin were in Orestimba and Hospital Creeks. 相似文献
460.
Barry R. Taylor Hal R. Hamilton Gordon Macdonald 《Journal of the American Water Resources Association》1993,29(2):235-247
ABSTRACT: River solute loads have seldom been measured in very large, complex drainage basins, nor have the methods of calculating loads been critically examined. For sites in the Saskatchewan River Basin, Canada, rating curves were poor predictors of solute loads because correlations between discharge and total solutes concentration were weak (R2 < 0.05 in most cases) and suffered from hysteresis. In contrast, the interval method produced reliable estimates in all seasons and sites tested, and was little affected by sampling schedule. The limit of precision (SE) for estimates of mean annual or seasonal solute load was 10–15 percent of the mean (5 percent in very small basins), reached with 10 years or more of data. Two-thirds or more of total annual solute load was transported during the open-water season, but the proportion carried during winter increased from 8 percent to 34 percent from the upstream to the downstream end of the basin, due to reservoirs retaining and mixing water. Annual loads of total solutes varied from 6.2 × 104 tonnes in foothills tributaries to almost 4.0 × 106 tonnes in the Saskatchewan River near the mouth. But, on an areal basis, the mountain and foothills region was the dominant solute source, producing 43–97 tonnes/km2/yr, compared with only 3–22 tonnes/km2/yr for prairie rivers. This difference is a consequence of greater rainfall and, hence, more rapid erosion in the mountains. 相似文献