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531.
Irina Cech Ernst M. Davis Edward A. Gonzales Diana Brooks 《Journal of the American Water Resources Association》1979,15(6):1691-1706
ABSTRACT: Application of synographic techniques to four separate nonrelated research tasks demonstrated the usefulness of such an approach in interpreting and communicating hydrologic survey data especially when large geographic areas are involved. Nutrient exchange and biotic indicators in coastal estuaries were analyzed to determine residence times in different seasons of the year. Man induced changes in urban runoff patterns were shown to increase the probability of flooding with different recurrences of storm events. Nitrate and indicator bacteria in private wells were analyzed on a county-wide basis to determine the sources and extent of natural occurrence versus contamination origins. Water wells and the surface supply of metropolitan Houston were analyzed for sodium content to assist citizens and physicians with data which are needed for derivation of sodium restricted therapeutic diets. 相似文献
532.
533.
Bamboo in climate change and rural livelihoods 总被引:1,自引:0,他引:1
Maxim Lobovikov Dieter Schoene Lou Yping 《Mitigation and Adaptation Strategies for Global Change》2012,17(3):261-276
Climate change negotiations, assessments, and greenhouse gas inventory guidelines have all but bypassed bamboo. Disallowing
stands of tree-like bamboos as forests disparages their function in the carbon (C) cycle, and disregards pillars of smallholder
livelihoods. Exposing bamboo not as a panacea, but as an overlooked option for C conservation, sequestration, and adaptation,
we screen details of distribution, morphology, growth, physiology, and impacts for pertinence to climate change. Additional
to 40 million hectares of existing bamboo forests, many potential host countries for C projects harbor suitable sites. Definitions,
methods and default values, such as the root/shoot- ratio, biomass conversion factors, allometric equations and sampling variables
need adjusting. Rapid maturation, persistent rhizomes, a rich palette of species, and wind-firmness may mitigate risk. Bamboos
can accommodate agro-and urban forestry, and reign in unsustainable shifting cultivation. Distribution functions of bamboo
biomass stocks and growths do not deviate drastically from those of trees. If anything, bamboo stocks are slightly lower,
and growths slightly higher, with medians of 87 t*ha−1 and 10.5 t*ha−1*yr−1, respectively. However, bamboo’s outstanding socio-economic effects might well determine its future in mitigation and adaptation.
Early, continuous yields, selective harvesting on even small parcels of land, low capital and high labor intensity, virtually
100% conversion efficiency to about 1,500 products, and, typically, 75% of economic returns benefiting rural people are advantageous
attributes. Regional studies on suitability, silviculture, yields, economics, risk, and C assessment would strengthen bamboo’s
function as ‘the poor man’s timber’ and promote its niche as the smallholder’s C sink. 相似文献
534.
Material efficiency: A white paper 总被引:1,自引:0,他引:1
Julian M. Allwood Michael F. AshbyTimothy G. Gutowski Ernst Worrell 《Resources, Conservation and Recycling》2011,55(3):362-381
For most materials used to provide buildings, infrastructure, equipment and products, global stocks are still sufficient to meet anticipated demand, but the environmental impacts of materials production and processing, particularly those related to energy, are rapidly becoming critical. These impacts can be ameliorated to some extent by the ongoing pursuit of efficiencies within existing processes, but demand is anticipated to double in the next 40 years, and this will lead to an unacceptable increase in overall impacts unless the total requirement for material production and processing is reduced. This is the goal of material efficiency, and this paper aims to stimulate interest in the area. Four major strategies for reducing material demand through material efficiency are discussed: longer-lasting products; modularisation and remanufacturing; component re-use; designing products with less material. In industrialised nations, these strategies have had little attention, because of economic, regulatory and social barriers, which are each examined. However, evidence from waste management and the pursuit of energy efficiency suggests that these barriers might be overcome, and an outline of potential mechanisms for change is given. In bringing together insights into material efficiency from a wide range of disciplines, the paper presents a set of 20 open questions for future work. 相似文献
535.
Environmental cross-compliance mitigates nitrogen and phosphorus pollution from Swiss agriculture 总被引:1,自引:0,他引:1
In 1993 the Swiss agricultural policy was revised with – amongst other goals – the objective of improving the environmental performance of agriculture. A voluntary agri-environmental scheme to promote integrated production (IP) was introduced. In 1999 the IP standards were integrated in cross compliance requirements and termed Proof of Ecological Performance (PEP). We evaluated the effectiveness of this policy in terms of reducing diffuse nitrogen (N) and phosphorus (P) pollution of ground and surface water. We combined monitoring schemes covering the reference period from before the introduction of IP/PEP (1990–1992) with the evaluation of cause/effect relationships in selected case-study areas. The evaluation showed an overall reduction of diffuse N and P pollution from agriculture even though some goals were not reached. Nitrate leaching declined, but only a 3–4 mg L−1 reduction was observed rather than the intended decrease of 5 mg L−1. The P pollution of surface waters from agriculture decreased by only 10–30% instead of 50%. The intended reduction of the nitrogen surplus of Swiss agriculture by 33% was not attained, but the P surplus of Swiss agriculture was more than halved. IP/PEP practices that improved N and P management included reduced N and P fertiliser inputs and pig and poultry feedstuffs with reduced N and P contents, both of which are a consequence of the requirement of equilibrated farm nutrient balances, as well as increased use of cover cropping and of conservation tillage systems. 相似文献