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651.
James C. Hower Uschi M. Graham Amy S. Wong J.David Robertson Bethel O. Haeberlin Gerald A. Thomas William H. Schram 《Waste management (New York, N.Y.)》1997,17(8):523-533
Two Kentucky power plants burning similar blends of high-sulfur western Kentucky and southern Indiana coal provide a unique opportunity to examine the variations in coal combustion by-products due to differences in the method of wet flue-gas desulfurization (FGD). One plant employed carbide lime-based scrubbing for two units and a dual-alkali process for the third unit. The second plant employed a Mississippian limestone from Kentucky for all four units. This study provides an example of optical and SEM petrographic techniques, supplemented by chemical analyses, applied to the study of, at least from the geologic perspective, non-traditional materials. The coal sources comprise a blend of high volatile C and B bituminous, high vitrinite (85–90%, mmf), high-sulfur (> 3%, dry) coals. The fly ash is dominated by glassy phases (70–80%) with about 5–10% spinel (predominately magnetite), 3–10% quartz, and 4–10% isotropic coke comprising the remaining portion of the ash. SEM observations indicate that the glassy particles exhibit a bimodal size distribution with sub-micron glass spheres and a population of larger (several 10s of microns) spheres. The bottom ash has higher proportions of spinels and mullite, with negligible carbon forms, compared to the fly ash from the same units. Fly ashes were observed to be lower in Fe and higher in Al, Si, and S compared to the bottom ashes. Carbide lime, a by-product of acetylene manufacture, soda ash, and limestone were the reagents used in the flue-gas desulfurization processes. The primary FGD by-product is a calcium sulfite slurry which is vacuum filtered and mixed with fly ash and, usually, lime, to form a stable product for disposal. The FGD by-products have some potential, as yet unrealized, for utilization. 相似文献
652.
The Midlands Region of the Environment Agency has developed a management system, in the form of an Environmental Action Plan (EAP) to ensure that the constraints and mitigation measures identified in the Environmental Statement document are delivered on the ground. The reasons are considered for developing such procedures and examples are provided of the environmentalobjectives and targets which lie at the heart of the new procedures. The EAP is designed to provide a summary of the environmental constraints, adverse effects and their associated mitigation measures, and monitoring requirements, in an easily accessible document for both technical and non-technical readers. 相似文献
653.
Concepts of sustainable development have stimulated innovation in the delivery of environmental management. In particular, new partnership approaches have been developed in recognition of the need to adopt more holistic perspectives and facilitate multi-sectoral and cross-sectoral working. River catchments are complex systems and have been one particular focus of experimentation in environmental management mechanisms. This paper provides a brief overview of river management experience in the UK, charting changing approaches in terms of scope and organisation since the 1970s. This sets the context for a more detailed examination of the Mersey Basin Campaign and, in particular, its River Valley Initiatives. The paper concludes with an evaluation of the merits of this approach in relation to sustainable river management. 相似文献
654.
The endangered Mauna Kea silversword (Argyroxiphium sandwicense ssp. sandwicense) has experienced a severe decline in distribution and abundance because of predation by alien ungulates. By the late 1970s only a small remnant natural population persisted on the Mauna Kea volcano on the Island of Hawaii. The Hawaii Department of Land and Natural Resources, Division of Forestry and Wildlife, initiated an outplanting program in the 1970s to promote recovery of A. sandwicense ssp. sandwicense. Intermittent outplanting since 1973 has generated an outplanted population of over 450 plants on Mauna Kea, but the program has unintentionally resulted in a major population bottleneck. All plants in the outplanted population appear to be first- or subsequent-generation offspring of only two maternal founders from the natural population. Genetic variation in the natural and outplanted populations was assessed for 90 random amplified polymorphic DNA loci. Eleven loci were detectably polymorphic in the natural population, whereas only three loci were detectably polymorphic in the outplanted population. Thus, the population bottleneck has been accompanied by a 73% reduction in the level of detectable polymorphism. In addition, for eight loci, the population bottleneck has resulted in the loss of the marker allele in the outplanted population. A management strategy involving manual pollen transfer has recently been implemented to incorporate additional founders from the natural population into the outplanting program. As a supplement to the outplanting program, the strategy also includes a program promoting direct seedling establishment following manual pollen transfer. Incorporating additional founders may serve to overcome the legacy of the population bottleneck, especially if founder representation can be equalized. 相似文献
655.
Kevin X. Cao Alice Booth Sebastien Ourselin Anna L. David Richard Ashcroft 《黑龙江环境通报》2018,38(7):475-481
The specialty of fetal surgery or fetal intervention is one of the most exciting emerging fields of modern medicine. It is made possible by decades of major developments in antenatal imaging, obstetric anaesthesia, fetal medicine, paediatric surgery, and of course by the bold and novel practitioners willing to take new steps to advance the field. Beginning in the 1970s, it has now reached a stage of maturity where there are several established in utero procedures and countless clinical trials and studies to develop more. But what is the legal situation that fetal surgeons find themselves in? What are the rights and legal protections for the fetus and the mother, both of which are arguably the patient? This article will address this question, discussing and summarising the current legal frameworks governing fetal surgery in the jurisdictions of the United Kingdom, European Court of Human Rights, and the United States of America as well as discuss what the future may hold and how researchers and physicians in the specialty can best navigate the legal environment. 相似文献
656.
Cliff I. Davidson Chris T. Hendrickson H. Scott Matthews Michael W. Bridges David T. Allen Cynthia F. Murphy Braden R. Allenby John C. Crittenden Sharon Austin 《Journal of Cleaner Production》2010,18(7):698-701
The field of engineering is changing rapidly as the growing global population puts added demands on the earth's resources: engineering decisions must now account for limitations in materials and energy as well as the need to reduce discharges of wastes. This means educators must revise courses and curricula so engineering graduates are prepared for the new challenges as practicing engineers. The Center for Sustainable Engineering has been established to help faculty members accommodate such changes through workshops and new educational materials, including a free access website with peer-reviewed materials. 相似文献
657.
W.David Conn 《Resources Policy》1977,3(1):23-38
This paper reviews the major problems that confronted the Committee set up by the Solid Waste Management Board of the state of California to prepare a background report and recommend alternative methods for reducing solid waste generation. The results of their analysis are presented, together with discussion of the conclusions reached. 相似文献
658.
David Humphreys 《Natural resources forum》1982,6(3):239-246
The concept of mineral consumption is considered in the context of a (metallic) commodity's progression from mine to manufacture and reasons are advanced as to why consumption is best measured at the point referred to as the “first processing stage.” Two methods for measuring consumption at this stage, one direct (“reported consumption”) and one deductive (“apparent consumption”), are described and the merits and drawbacks of the methods discussed. The article concludes with a brief review of the existing statistics on worldwide mineral consumption and suggests that there is the scope, and the need, for improvement. Dans cet article, la notion de la consommation minérale est envisagée dans le cadre de l'acheminement du minerai (métallique) de la mine à l'usine de transformation. II donne les raisons pour lesquelles la consommation peut se mesurer le mieux au niveau de la “phase de première transformation.” A ce stade, l'article décrit deux méthodes permettant de mesurer cette consommation: l'une directe (la consommation déclarée) et l'autre supposée (la consommation apparente). Les avantages et les inconvénients des méthodes y sont aussi discutés. En conclusion, l'article passe brièvement en revue les statistiques existantes sur la consommation minérale mondiale et suggère que la possibilité ainsi que le besoin d'amélioration se font sentir dans ce domaine. El concepto de consumo de minerales se examina dentro del contexto de la progresión del producto desde la mina a la manufactura y se sostiene que dicho consumo se mide mejor en la “etapa de primer procesamiento.” Se describen dos métodos para medir el consumo en esta etapa, el método directo (consumo reportado) y deductivo (consumo aparente). Se discuten las ventajas y desventajas de estos métodos. El artículo concluye con una revisión breve de las estadísticas existentes del consumo de minerales a nivel mundial y sugiere que existe la necesidad y la posibilidad para mejorarlas. 相似文献
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