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971.
In recent years there has been an increase in the intensity and frequency of environmental monitoring surveys at UK sewage sludge disposal sites. These have been carried out by the regulatory authorities and by the licensees. in order to ensure maximum efficiency, a coordinated and harmonised programme of monitoring has been developed. the programme concentrates on sediment chemical and biological quality but also includes assessments of water and fish quality
In England and Wales the Ministry of Agriculture, Fisheries and Food is the regulatory authority and the Water Authorities are the licensees. the Ministry's first priority is the collection of samples for temporal trend analysis but in addition, infrequent surveys are made to check the status of the disposal site and surrounding areas. in the periods between status surveys, regular spatial surveys designed to define the area of impact are carried out by the Water Authorities. 相似文献
In England and Wales the Ministry of Agriculture, Fisheries and Food is the regulatory authority and the Water Authorities are the licensees. the Ministry's first priority is the collection of samples for temporal trend analysis but in addition, infrequent surveys are made to check the status of the disposal site and surrounding areas. in the periods between status surveys, regular spatial surveys designed to define the area of impact are carried out by the Water Authorities. 相似文献
972.
Wang Haiying Fan Zhenjun Hou Xiaoli Dong SuochengInstitute of Geographical Sciences Natural Resources Research CAS Beijing China 《中国人口.资源与环境(英文版)》2004,2(1)
Since the 1990s, the Yellow River stream has been temporarily interrupted for several years, which affects the development of society, the economy and human life, limits the economic potential of the drainage areas, and especially causes great harm to regions on the lower reaches. Based on the analysis of the relationship between the development of society and economy and water scarcity, the author thinks it is necessary to optimize and adjust the industrial structure that has extravagantly consumed enormous amounts of water, and to develop ecological agriculture, industry and tourism which are balanced with the ecological environment. Finally, the author puts forward several pieces of advice and countermeasures about how to build the economic systems by which water can be used economically. 相似文献
973.
Alessandra Pugnetti Francesco Acri Luisa Alberighi Donato Barletta Mauro Bastianini Fabrizio Bernardi-Aubry Andrea Berton Franco Bianchi Giorgio Socal Cecilia Totti 《Chemistry and Ecology》2004,20(6):399-409
Taxonomic composition, biomass, primary production and growth rates of the phytoplankton community were studied in two stations in the NW Adriatic Sea on a seasonal basis, in areas characterized by differing hydrological and trophic conditions. The main differences between the two stations were quantitative rather than qualitative, most phytoplankton species being common to both stations. The effects of differing nutrient concentrations and plume spreading were evident. Biomass and primary production rates were significantly higher in the coastal station (S1), and the phytoplankton distribution in the water column was markedly stratified in S1 and more even in the offshore station (S3). However, chlorophyll a specific production, potential growth rate and production efficiencies were very similar in both stations, even when phosphorus concentrations were limiting. A discrepancy between potential and actual growth rate was observed: as a feature common to both stations, comparisons between potential and actual growth rates revealed that little carbon produced by phytoplankton accumulated as algal biomass; therefore, very high loss rates were estimated. 相似文献
974.
黄河巨洪发生时间规律的讨论 总被引:3,自引:0,他引:3
本文讨论了黄河巨洪发生的三个时间规律。一是巨洪一般发生在太阳活动的峰年或谷年;二是巨洪发生在甘、新、蒙交接区7级以上大震后一年内;三是巨洪发生在重合于25年周期的年份(从1933年算起),以及重合于这个周期的公度性年份和黄金分割年份。另外对太阳活动和巨洪的相关机制和大震与巨洪之间的相关机制也作了讨论。 相似文献
975.
Maurizio Pettine Silvio Capri Maria Giuseppina Farrace Maura Manganelli Luisa Patrolecco Alberto Puddu Annamaria Zoppini 《Chemistry and Ecology》2002,18(1):13-25
The results obtained in the four seasonal cruises planned in the PRISMA II project are reported. These concern dissolved and colloidal organic carbon, free amino acids and total dissolved carbohydrates and heterotrophic activity. Main factors controlling organic matter degradation, resulting from laboratory tests not planned in the above project, are also discussed. Dissolved organic matter shows seasonal accumulation, which may be markedly different from year to year, and large contributions by colloidal and saccharide components. Heterotrophic activities play an important role in the carbon cycle, although laboratory runs highlight limitations caused by aging of organic matter and phosphorus deficiency. 相似文献
976.
Fossi MC Casini S Marsili L 《Environmental science and pollution research international》2006,13(3):204-207
- DOI: http://dx.doi.org/10.1065/espr2006.01.018
Background, Aims and Scope
Man-made Endocrine Disruptors (EDs) range across all continents and oceans. Some geographic areas are potentially more threatened
than others: one of these is the Mediterranean Sea. Levels of some xenobiotics are much higher here than in other seas and
oceans. In this paper we review the final results of a project in which the hypothesis that Mediterranean top predator species
(such as large pelagic fish and marine mammals) are potentially at risk due to EDs was investigated.
Methods In a four-year survey on the Mediterranean population of swordfish (Xiphias gladius), the potential toxicological effects
of organochlorine compounds (OCs) on specimens of swordfish and tuna fish (Thunnus thynnus thynnus), caught in the spawning
seasons from 1999 to 2002 in the Straits of Messina, Sicily (Italy), were investigated using vitellogenin (Vtg), Zona radiata
proteins (Zrp), and cytochrome P4501A (CYP1A) activities (EROD, BPMO). Tissues (skin and blubber) were obtained from Stenella
coeruleoalba, Tursiops truncatus, Delphinus delphis and Balaenoptera physalus from the western Ligurian Sea, between Corsica
and the French-Italian coast, and Ionic Sea using biopsy darts launched with a crossbow. Benzo(á)pyrene monoxigenase (BPMO)
activity was mesured in biopsies and cholrinated hydrocarbon levels were detected.
Results and Discussion We illustrate the need to develop and apply sensitive methodological tools, such as biomarkers (Vitellogenin, Zona Radiata
proteins and CYP1A activities) for evaluation of toxicological risk in Xiphias gladius and Thunnus thynnus thynnus), and nondestructive
biomarkers (CYP1A activities and fibroblast cell culture in skin biopsy), for the hazard assessment of threatened marine mammals
species (Stenella coeruleoalba, Tursiops truncatus, Delphinus delphis and Balaenoptera physalus) exposed to EDs.
Conclusion The present research shows that: a) Vtg and Zrp can be used as diagnostic tools for fish stocks hazard assessment in the
Mediterranean Sea; b) that CYP1A1 (BPMO) induction in cetaceans skin biopsy may be an early sign of exposure to EDs such as
OCs and a potential alert for transgenerational effects.
Recommendation and Outlook This research represents a warning signal of the potential reproductive alterations in marine top predators and suggest the
need for continuous monitoring to avoid reductions in population and biodiversity in the Mediterranean Sea. 相似文献
977.
Abstract The issue on water environmental degradation in the source area of the Yellow River has been one of very serious ecological and socially economic problems. The temporal-spatial changes of water environment led to the decreasing of land capacity and river disconnecting. The status of water environmental degradation in this paper was analyzed based on the data and field investigation. The results indicated that the surface water area in the region has obviously decreased owing to the climate changes and human irrational use of water resources and the continuous lowering of the regional groundwater table and the steadily decreasing tendency of the flow rate in the source areas of the Yellow River. 相似文献
978.
979.
980.
进行了用纳氏试剂比色法直接测定海水中氨氮的试验。试验表明,可用酒石酸钾钠溶液—氢氧化钠溶液作为掩蔽剂排除海水中钙、镁离子对测定的干扰。着重对氢氧化钠溶液用量、显色剂用量和显色时间进行了试验,以用200g/L氢氧化钠溶液2.5mL,纳氏试剂1.5mL,显色25min为最佳测定条件,并对水样中的盐度影响作了考察。氨氮质量浓度在0.01mg/L—0.40mg/L范围内符合比耳定律,检出限为0.01mg/L;平行样相对偏差为9%,加标回收率在91%—108%之间;相对盐度为10—32的海水可以直接测定。 相似文献