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981.
Andrew Mackillop 《Natural resources forum》1980,4(2):165-179
High costs of all commercial (especially imported) fuels have had especially severe impacts on the developing nations and, within these, on the most disadvantaged regions and socio-economic groups. Improving the security of supply while stabilizing prices has become a major energy-economic need. For the less developed nations this particularly calls for greater indigenous energy production and improved regional supply without massive capital commitments. Solar and renewable sources have a critical part to play in this. Certain of these appear promising for immediate development. For the longer term their potentials are far greater — but economic acceptance requires changed evaluation methods. Les pays en développement, et parmi eux les régions et groupes socioéconomiques les plus défavorisés, ont fortement ressenti les incidences particulièrement graves de la hausse des prix des combustibles commerciaux (et plus spécialement, des combustibles importés). S'assurer plus attentivement de l'approvisionnement tout en contenant le niveau des prix est devenu un impératif de leur politique énergético-économique. En ce qui concerne ces pays, cet effort requiert en particulier une production plus abondante d'énergie locale et une amélioration des approvisionnements régionaux sans engagements de capitaux démesurés. Les sources d'énergie solaire et d'énergie de remplacement ont un rôle significatif à jouer dans ce domaine. Quelques-unes d'entre elles destinées à certaines utilisations semblent pouvoir être mises en valeur dans l'immédiat. A longue échéance, leur potentiel est encore d'une plus grande portée. Cependant, pour les rendre rentables, leur méthodes d'évaluation serait à repenser. El alto costo de los combustibles (especialmente los importados) ha tenido un impacto especialmente severo en los paises en desarrollo, particularmente en las regiones y los grupos socioeconómicos que se encuentran en situación desventajosa. Mejorar la seguridad del suministro procurando al mismo tiempo mantener los precios estables se ha convertido en una necesidad importante dentro de la economía de la energía. Para los paises menos desarrollados esto significa especialmente desarrollar recursos energéticos propios y mejorar el suministro regional sin comprometer capital en forma masiva. Los recursos renovables (energiá solar) tienen un rol de importancia crítica y algunos de ellos parecen promisorios para su desarrollo immediato. Para el largo plazo el potencial de estos recursos es mucho mas grande aún — pero su aceptación económica requiere todos de evaluación nuevos. 相似文献
982.
Four fish species were collected: brown trout, grouper, spotted tail bass, and black crappie. Fish samples were thawed and dissected. The pieces of edible muscle and liver tissues were digested in a reagent-grade nitric acid, in a constant temperature shaking-water bath at 58°C. Thirteen inorganic elements were determined by flame atomic absorption.The significant findings of this report are that inorganic elements, mercury, iron, copper, zinc, chromium, and nickel with the exception of magnesium show elevated levels in the livers than in the muscles of all the four fish species. It seems magnesium concentration levels were consistantly higher in the muscles than in the livers of all four fish species. It is found that calculations of muscle-liver ratios indicate that ratios in the range of 0.5 are preliminary indicative of environmental static conditions, whereas ratios in the range of more than one are indicative of environmental improvement. 相似文献
983.
Andrew B. Sparks Eric T. Wang Craig A. Struble Wade Barrett Renee Stokowski Celeste McBride Jacob Zahn Kevin Lee Naiping Shen Jigna Doshi Michel Sun Jill Garrison Jay Sandler Desiree Hollemon Patrick Pattee Aoy Tomita-Mitchell Michael Mitchell John Stuelpnagel Ken Song Arnold Oliphant 《黑龙江环境通报》2012,32(1):3-9
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988.
James R Marsden David E Pingry Andrew B Whinston 《Journal of Environmental Economics and Management》1976,3(2):154-163
Increased emphasis on pollution control and abatement has often necessitated development of large scale data bases. While sophisticated techniques have been developed and employed for data storage and manipulation, parallel developments in analyzing the accuracy and reliability of the data have been absent (see, for instance, the broad spectrum of requirements outlined in the Federal Water Pollution Control Act Amendments of 1972).This paper centers on the latter and sets out a procedure for data editing and “outlier” identification based on an application of discriminant analysis. A hypothetical example is included along with some suggested applications. 相似文献
989.
990.
Lee W. Cooper Jacqueline M. Grebmeier I. L. Larsen Scott S. Dolvin Andrew J. Reed 《Chemistry and Ecology》1998,15(1):27-46
Extensive surveys of sediment burdens of radiocaesium, specifically 137Cs, and other radioactive contaminants in the Arctic during the 1990's, indicate that almost all anthropogenic radionuclides buried on continental shelves adjacent to Alaska are derived from global bomb fallout. the 137Cs (half-life: 30.2y) activities observed in surface (0-4 cm) marine sediments however, vary widely, albeit much less than the expected current inventory resulting from bomb fallout at this latitude (∼100mBq cm-2). This observed geographical variation provided the opportunity to evaluate physical and biological mechanisms that may affect caesium biogeochemistry on Arctic continental shelves. We investigated whether high biological productivity in portions of the Bering and Chukchi Seas is effective in removing dissolved radiocaesium from the water column, and whether biological production in overlying water affects total radiocaesium inventories in sediments. Based upon C/N ratios in the organic fraction of shallow sediments, we found no evidence that higher inventories or surface activities of radiocaesium are present in areas with higher deposition of particulate organic matter. Based upon stable carbon isotope ratios of organic matter in sediments, we found no evidence that terrestrial runoff contributes proportionally to higher surface activities, although terrestrial runoff may affect total inventories of the radionuclide. Radiocaesium content of surface sediments was significantly correlated with total organic carbon content of sediments and the proportion of sediments in the finest sediment fractions. Because high current flow can also be expected to influence distributions of those sedimentary parameters, we conclude that re-distribution of 相似文献