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291.
292.
Open-focused microwave-assisted extraction and ICP-OES determination of As, Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn from surface sediments of the estuary of Bilbao (Basque Country, North of Spain) was carried out. All the samples were collected at three different tributaries of the estuary (Asua, Galindo and Nerbioi-Ibaizabal) every two months during 1999. The digestion procedure was proposed from the conclusions of a fractionated factorial design, and the precision and accuracy of the method was verified using a certified reference sediment (RTC008-050). The results of the analysis were statistically treated by means of principal component analysis and correlation analysis. The principal component analysis of sediment data (32 samples × 9 metals) indicated different patterns of contamination regarding the tributary and sampling station. The two main patterns observed were a steady increment of the metal concentration along all the campaigns in the samples collected in the Galindo River and a seasonal variation in the Nerbioi-Ibaizabal River, with higher metallic content during summertime and lower content during wintertime. 相似文献
293.
Significance of platinum group metals emitted from automobile exhaust gas converters for the biosphere 总被引:1,自引:0,他引:1
Intention, Goal, Scope, Background Following the introduction of automobile catalytic converters the platinum group metals (PGM) platinum (Pt), palladium (Pd)
and rhodium (Rh) gain on increasing interest in environmental research as these metals are emitted with exhaust fumes into
the environment. Consequently, elevated PGM levels were found in different environmental matrices uch as road dusts, soils
along heavily frequented roads, sediments of urban rivers etc. Accordingly, the effects of increasing PGM emissions on the
biosphere are controversially discussed.
Objective This paper summarizes the present knowledge on the biological availability of PGM to plants and animals. As biological availability
is one of the most decisive factors determining the toxicologi-cal potential of xenobiotics, this information is very important
to evaluate the possible threat of the noble metals to ecosystems.
Results and Discussion The availability of soluble as well as particle bound PGM to terrestrial plants was demonstrated in several studies. Experimental
investigations revealed uptake of Pt, Pd and Rh also by aquatic plants. Additionally, the biological availability of the noble
metals for animals has been verified in experimental studies using soluble metal salts, catalytic converter model substances,
sediments of urban rivers, road dust or tunnel dust as metal sources. These studies refer mainly to aquatic animals. Beside
of free living organisms, in particular worms parasitizing fish demonstrated a high potential to accumulate PGM. This could
be of great interest in respect of biomonitoring purposes. Generally, for plants as well as for animals Pd turns out to be
the best available metal among the PGM. Compared to other heavy metals, the biological availability of PGM from road dust
to zebra mussels(Dreissena polymorpha) ranged between that of Cd and Pb.
Conclusion Especially chronic effects of PGM on the biosphere can not be excluded due to (1) their cumulative increase in the environment,
(2) their unexpected high biological availability and bioaccumulation and (3) their unknown toxicological and ecotoxicological
potential. However, it appears that acute effects on ecosystems due to anthropogenic PGM emission are not likely.
Recommendation and Outlook Research on environmental PGM contamination of the biosphere, especially the fauna, and on long-term toxiciry of low PGM concentrations
is highly appreciated. These studies require very sensitive analytical techniques to determine PGM even in low sample amounts.
Research has to be done in particular on reliable determination of (ultra) trace levels of Pd and Rh as the lack of data on
these two metals is mainly due to analytical problems. 相似文献
294.
Belias CV Bikas VG Dassenakis MJ Scoullos MJ 《Environmental science and pollution research international》2003,10(5):287-295
GOAL, SCOPE AND BACKGROUND: Over the last decade Greece has become a leading country in the EU as concerns the cage farming of seabream and seabass. A strong debate has risen, however, about the environmental impacts of aquacultures in the coastal areas. The present paper deals with this problem and it is based on measurements of physico-chemical parameters in the water column, particulate matter and sediments in the area of Astakos Gulf, a coastal embayment in western Greece where three big fish farms are currently operating. METHODS: Water samples were collected by using Hydro-Bios sampling bottles, whereas a prototype sediment trap was installed under a fish cage for the collection of particulate matter. Temperature, dissolved oxygen, pH and salinity were measured in situ using portable equipment. Nutrients were determined by standard spectrophotometric methods. Trace metals were determined by Atomic Absorption Spectrometry. Dissolved organic carbon was determined by a Shimadzu 5000A carbon analyzer, whereas organic carbon in sediments was determined titrimetrically. RESULTS AND DISCUSSION: No clear eutrophication incidents have been identified, although the water column near the fish farms was enriched in nutrients and organic carbon. A sludge 'blanket' covers considerable parts of the seabed and is enriched in colloidal organic carbon and trace metals (Cd, Cu, Fe and Zn) that come from unused fish food. The biodegradation of this sludge leads to the development of anoxic conditions followed by the formation of undesirable gases, precipitation or remobilization of metals and the extinction of benthic fauna. CONCLUSION: The operation of fish farms at the coastal area of Astakos Gulf, and probably in similar Mediterranean gulfs, affects the marine environment, particularly in the vicinity of the cages. The most significant influence concerns the near-bottom water layer. The environmental impacts depend on the amount of food given to fishes, the mode of feeding, the fish density in cages, the annual production and the years of unit operation. The hydrology and the geomorphology of the area are also critical factors for its environmental quality. RECOMMENDATION AND OUTLOOK: The success of the fish-farming sector in the Mediterranean is accompanied by environmental and, in some extents, by social and marketing problems. These problems, derived from the rapid development of fish farming, can be solved only through an integrated management, using methods such as environmental impact assessment, risk assessment, economic evaluation, vulnerability assessments, resource accounting, cost-benefit analysis and outcome-based monitoring. 相似文献
295.
宝应县土壤重金属的污染调查 总被引:1,自引:0,他引:1
以宝应县农田土壤重金属调查为依据,采用污染指数法对土壤质量进行评价,分析土壤重金属污染原因,提出防治措施。 相似文献
296.
Klumpp A Ansel W Klumpp G Belluzzo N Calatayud V Chaplin N Garrec JP Gutsche HJ Hayes M Hentze HW Kambezidis H Laurent O Peñuelas J Rasmussen S Ribas A Ro-Poulsen H Rossi S Sanz MJ Shang H Sifakis N Vergne P 《Environmental science and pollution research international》2002,9(3):199-203
EuroBionet, the 'European Network for the Assessment of Air Quality by the Use of Bioindicator Plants', is an EU-funded cooperative project currently consisting of public authorities and scientific institutes from 12 cities in 8 countries. In 2000, the bioindicator plants tobacco (Nicotiana tabacum Bel W3), poplar (Populus nigra 'Brandaris'), spiderwort (Tradescantia sp. clone 4430), Italian rye grass (Lolium multiflorum italicum) and curly kale (Brassica oleracea acephala) were exposed to ambient air at 90 monitoring sites according to standardised methods. Visible injuries and growth parameters were assessed and the accumulation of toxic substances in leaves determined. The exposure of tobacco resulted in a gradient with low levels of ozone-induced foliar injury in N and NW Europe, and medium to high values in the southern and central regions. The results of heavy metal and sulphur analyses in rye grass samples generally showed low to very low sulphur and low to medium heavy metal concentrations in leaves. In some cities, however, local hot spots of heavy metal contamination were detected. Analyses of the PAH contents in curly kale leaves gave low to medium values, with locally elevated levels at traffic-exposed sites. 相似文献
297.
298.
299.
膨润土对Pb2+、Cu2+、Cr3+的吸附动力学及等温线研究 总被引:1,自引:0,他引:1
研究所用膨润土的主要成分为SiO2和Al2O3,属于Ca基膨润土,BET表面积为50.83 m2/g.在恒温及恒定pH条件下,用静态吸附法研究了膨润土对Pb2 、Cu2 、Cr3 的吸附特性,结果表明其较好地符合Lagergten二级吸附速率方程,对这3种离子的吸附速率为Pb2 >Cu2 >Cr3 .利用3种等温线方程对吸附过程进行拟合,发现利用Langmuir吸附等温方程计算的值与膨润土吸附Pb2 、Cu2 、Cr3 试验数据最为吻合.膨润土对3种金属离子的平衡吸附量为Cr3 >Cu2 >Pb2 . 相似文献
300.
Brayner FM da Silva HK Barbosa AM 《Environmental science and pollution research international》2001,8(4):269-274
An analytical procedure involving a three-step sequential extraction was used to determine the chemical association of heavy metals (Zn, Cr, Mn and Fe) with the major phases (exchangable, reducible and oxidizable) in samples from a fishpond of estuarine sediments. The pond is located in the Capibaribe River estuary, within the boundaries of the city of Recife, in the State of Pernambuco in the northeast of Brazil. The total metal content was determined as well. All metals were extracted from the residual fraction at a percentage greater than 50%. 相似文献