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971.
D.B. Lee K.B. Lee C.H. Kim J.G. Kim S.Y. Na 《Environmental geochemistry and health》2004,26(2):135-145
This study was carried out to evaluate water quality, sediment and plant vegetation in eight tributaries of the Mankyeong River for enhancement of natural purification. Among the tributaries, the Iksancheon water had the highest concentration of BOD, T–N and NH4–N due to inflow of swine wastes from the livestock district. The Yucheon water had the highest level of electrical conductivity and SO
4
2–
due to inflow of mis-treated wastewater from industrial districts. The Tabcheon had generally similar concentrations of nitrogen and phosphate to that of the upstream of the Mankyeong River: agricultural activity along the Tabcheon appeared to have little negative influence to the water quality. Among various sediments, concentration of organic matter, nitrogen and phosphate were high in the Iksancheon and the Yucheon due to the livestock wastes and industrial wastes. There were 282 species of plants during summer with 43 aquatic plants, 57 hydrophytes, 178 waterside plants and 4 terrestrial plants. Some plant resources were recommended due to much absorption of nitrogen and phosphate for enhancement of natural purification. C. demersum and H. verticillata were recommended in the submerged aquatic plants, H. dubia, N. indica and N. subinteperrimum in the floating leaf aquatic plants, P. communis, Z. latifolia and T. orientalis in the emerged aquatic plants, C. scutata and P. distichum in the waterside plants. 相似文献
972.
Hydrochemical Monitoring and Heavy Metal Contaminations at the Narim Mine Creek in the Sulcheon District, Republic of Korea 总被引:1,自引:0,他引:1
The Narim gold mine is located approximately 200km southeast of Seoul within the Sulcheon mineralised district in the Yeongnam massif, Korea. In this study, environmental geochemical analyses were undertaken for soil, sediment and water samples collected in April, September and November in 1998 from the Narim mine creek. The mine area consists mainly of granitic gneiss; however, mineral constituents of soil and sediment near the mine were mainly composed of quartz, feldspar, mica, amphibole, some pyrite and clay minerals. Also were found some pyrite, arsenopyrite, chalcopyrite, sphalerite, galena, malachite, goethite, various hydroxide and unidentified secondary minerals. Generally, high concentrations of heavy metals in the soil and sediment are correlated with a high proportion of secondary minerals. Hydrochemical compositions of water samples are characterised by relative significant enrichment of Na++K+ and alkali metals in the ground water, whereas the surface and mine waters are relatively enriched in Ca2++Mg2+ and heavy metals. Anion contents of the ground waters are typically enriched in HCO3
–, NO3
– and Cl–, whereas the surface and mine waters are highly enriched in HCO3
– and SO4
2–. The pH and EC values of the surface water from the non-mine creek are relatively lower compared with those of the surface water around the mine and waste dump. The range of D and 18O values (d parameters) of the water samples are shown in distinct two groups for the April waters of 10.1–13.1, and for the November waters of 5.8–7.9, respectively. This range variation indicates that two group water were composed of distinct waters because of seasonal difference. Geochemical modelling showed that mostly heavy toxic metals may exist largely in the form of free metal (M2+) and metal-sulphate (MSO4
2–), and SO4
2– concentration influenced the speciation of heavy metals in the mine water. These metals in the ground water could be formed of CO3
– and OH– complex ions. Using a computer program, saturation indices of albite, calcite, dolomite in mostly surface water show undersaturated and progressively evolved toward the saturation state, however, ground and mine waters are nearly saturated. The gibbsite, kaolinite and smectite are supersaturated in the surface and ground water, respectively. Calculated water-mineral reaction and stabilities suggest that the weathering of silicate minerals may be stable kaolinite. The clay minerals of K-illite and Na-smectite will be transformed to more stable kaolinite owing to the continuous reaction. 相似文献
973.
Terence R. Lee 《Natural resources forum》1979,3(4):401-416
This article discusses some recent developments in water management in Latin America. It is based on research done during the joint CEPAL/UNEP project on Water Development and the Environment. The author discusses the changes in water use occurring in Latin America in general, the contemporary relationship with the water resource in four major metropolitan centres, Bogotá, Colombia, Lima, Peru, and Sāo Paulo and Rio de Janeiro, Brazil. On the basis of the general and specific experiences described, general conclusions are drawn as to styles of water management current in the region and adjustments to the problem posed by the emergence of very large metropolitan concentrations of population and economic activity. Cet article reprend des développements récents en matière de gestion des ressources en eau en Amérique latine. II se base sur des recherches effectuées au cours de l'exécution du projet conjoint CEPAL/PNUE sur la mise en valeur des ressources en eau et de l'environnement. L'auteur discute des modifications intervenues dans l'utilisation des ressources en eau en Amérique latine en général et le rapport qui existe actuellement entre les ressources en eau et quatre centres principaux urbains (Bogota en Colombie, Lima au Pérou, et Sāo Paulo et Rio de Janeiro au Brésil). Sur la base des experiences générales et particulières décrites, des conclusions génèrales sont tirées quant aux modes de gestion actuelle des ressources en eau dans la région et aux améliorations apportées au problème créé par l'apparition d'énormes agglomérations urbaines à activité économique intense. Este artículo trata sobre algunos desarrollos recientes en la administración del uso de recursos de agua en Latinoamérica. El artículo está basado en la investigación realizada en el proyecto conjunto CEPAL/PNUMA sobre Desarrollo de Agua y el Medio Ambiente. El autor analiza los cambios que están ocurriendo en el uso de recursos de ague en Latinoamérica en general y las relaciones entre los recursos de agua y los usos en cuatro centros metropolitanos: Bogotá, Lima, Sāco Paulo y Rio de Janeiro. Basándose en descripciones de experiencias generales y específicas, se extraen conclusiones sobre los estilos de la administración de recursos de agua existentes en la región y sobre la solución a los problemas planteados por la emergencia de grandes concentraciones metropolitanas de población y actividad económica. 相似文献
974.
Choi MS Lin XJ Lee SA Kim W Kang HD Doh SH Kim DS Lee DM 《Journal of environmental radioactivity》2008,99(8):1319-1323
The concentrations of naturally occurring radioisotopes ((232)Th, (228)Th, (230)Th, (228)Ra, (226)Ra, and (40)K) in typical Korean foods were evaluated. The daily intakes of these radioisotopes were calculated by comparing concentrations in typical Korean foods and the daily consumption rates of these foods. Daily intakes were as follows: (232)Th, 0.00-0.23; (228)Th, 0.00-2.04; (230)Th, 0.00-0.26; (228)Ra, 0.02-2.73; (226)Ra, 0.01-4.37 mBq/day; and (40)K, 0.01-5.71 Bq/day. The total daily intake of the naturally occurring radioisotopes measured in this study from food was 39.46 Bq/day. The total annual internal dose resulting from ingestion of radioisotopes in food was 109.83 muSv/y, and the radioisotope with the highest daily intake was (40)K. These values were same level compiled in other countries. 相似文献
975.
Ching-Hwa Lee Hsin-Yi Yen Ching-Hua Liao Srinivasa R. Popuri Elon I. Cadogan Chuan-Jen Hsu 《Journal of Material Cycles and Waste Management》2017,19(1):102-110
An evaluation of various metal purification processes subsequent to the leaching processing of the neodymium (Nd) product from neodymium–iron–boron (Nd–Fe–B) magnets has been conducted. These post-leaching purification processes included precipitation; replacement and electrolysis were studied in order to check the purity of the recovered neodymium. A hydrometallurgical investigation was adopted to digest the metal content of the scrap Nd–Fe–B magnets for the recovery of valuable Nd metal and other metals such as Fe, B, Co and Ni. The effect of leaching conditions such as solid-to-liquid ratio and temperature were optimized and 100 % Nd, 100 % Fe, 100 % B and 85.87 % Co leaching efficiencies were achieved under these conditions. The coating material of the magnet, Ni, achieved 50 % impregnation after increasing the reaction temperature to 70 °C. The metals present in the optimal leaching solution were recovered 99 % by pH adjustment. However, the replacement had the highest separation efficiency for the recovery of Nd metal. Further, the optimal leaching Nd–Fe–B solution was subjected to the electrolysis processes in order to verify the recovery efficiency for all metals. 相似文献
976.
Kim Duk-Min Kwon Oh-Hun Oh Youn Soo Lee Jin-Soo 《Environmental geochemistry and health》2021,43(10):4105-4122
Environmental Geochemistry and Health - In the area around the abandoned Seoseong mine, South Korea, coastal paddy fields undergo seawater intrusion and possible sulfate reduction. Here, channel... 相似文献
977.
Lee Kwanyong Chantrasakdakul Phromphol Kim Daegi Kim Jin-Seog Park Ki Young 《Journal of Material Cycles and Waste Management》2017,19(1):235-240
Journal of Material Cycles and Waste Management - The purpose of this study was to investigate biogas productivity of algal residues from bioethanol production. Pre-treatment based on enzyme was... 相似文献
978.
979.
980.
A. H. M. Selim Reza Jiin-Shuh Jean Huai-Jen Yang Ming-Kuo Lee Hua-Fen Hsu Chia-Chuan Liu Yao-Chang Lee Jochen Bundschuh Kao-Hong Lin Chi-Yu Lee 《Environmental geochemistry and health》2011,33(3):235-258
Humic substances in groundwater and aquifer sediments from the arsenicosis and Blackfoot disease (BFD) affected areas in Bangladesh
(Bengal delta plain) and Taiwan (Lanyang plain and Chianan plain) were characterized using fluorescence spectrophotometry
and Fourier transform infrared (FT-IR) spectroscopy. The results demonstrate that the mean concentration of As and relative
intensity of fluorescent humic substances are higher in the Chianan plain groundwater than those in the Lanyang plain and
Bengal delta plain groundwater. The mean As concentrations in Bengal delta plain, Chianan plain, and Lanyang plain are 50.65 μg/l
(2.8–170.8 μg/l, n = 20), 393 μg/l (9–704 μg/l, n = 5), and 104.5 μg/l (2.51–543 μg/l, n = 6), respectively. Average concentrations and relative fluorescent intensity of humic substances in groundwater are 25.381 QSU
(quinine standard unit) and 17.78 in the Bengal delta plain, 184.032 QSU and 128.41 in the Chianan plain, and 77.56 QSU and
53.43 in the Lanyang plain. Moreover, FT-IR analysis shows that the humic substances extracted from the Chianan plain groundwater
contain phenolic, alkanes, aromatic ring and amine groups, which tend to form metal carbon bonds with As and other trace elements.
By contrast, the spectra show that humic substances are largely absent from sediments and groundwater in the Bengal delta
plain and Lanyang plain. The data suggest that the reductive dissolution of As-adsorbed Mn oxyhydroxides is the most probable
mechanism for mobilization of As in the Bengal delta plain. However, in the Chianan plain and Lanyang plain, microbially mediated
reductive dissolution of As-adsorbed amorphous/crystalline Fe oxyhydroxides in organic-rich sediments is the primary mechanism
for releasing As to groundwater. High levels of As and humic substances possibly play a critical role in causing the unique
BFD in the Chianan plain of SW Taiwan. 相似文献