全文获取类型
收费全文 | 17477篇 |
免费 | 281篇 |
国内免费 | 380篇 |
专业分类
安全科学 | 613篇 |
废物处理 | 737篇 |
环保管理 | 2591篇 |
综合类 | 2970篇 |
基础理论 | 4481篇 |
环境理论 | 7篇 |
污染及防治 | 4607篇 |
评价与监测 | 991篇 |
社会与环境 | 1016篇 |
灾害及防治 | 125篇 |
出版年
2023年 | 95篇 |
2022年 | 171篇 |
2021年 | 168篇 |
2020年 | 189篇 |
2019年 | 151篇 |
2018年 | 284篇 |
2017年 | 268篇 |
2016年 | 412篇 |
2015年 | 334篇 |
2014年 | 445篇 |
2013年 | 1408篇 |
2012年 | 614篇 |
2011年 | 885篇 |
2010年 | 669篇 |
2009年 | 759篇 |
2008年 | 824篇 |
2007年 | 868篇 |
2006年 | 716篇 |
2005年 | 603篇 |
2004年 | 621篇 |
2003年 | 563篇 |
2002年 | 536篇 |
2001年 | 642篇 |
2000年 | 518篇 |
1999年 | 315篇 |
1998年 | 209篇 |
1997年 | 228篇 |
1996年 | 221篇 |
1995年 | 266篇 |
1994年 | 209篇 |
1993年 | 208篇 |
1992年 | 174篇 |
1991年 | 182篇 |
1990年 | 178篇 |
1989年 | 180篇 |
1988年 | 153篇 |
1987年 | 133篇 |
1986年 | 156篇 |
1985年 | 143篇 |
1984年 | 190篇 |
1983年 | 147篇 |
1982年 | 171篇 |
1981年 | 157篇 |
1980年 | 130篇 |
1979年 | 149篇 |
1978年 | 94篇 |
1977年 | 98篇 |
1975年 | 88篇 |
1974年 | 93篇 |
1972年 | 96篇 |
排序方式: 共有10000条查询结果,搜索用时 62 毫秒
201.
Gunster DG Gillis CA Bonnevie NL Abel TB Wenning RJ 《Environmental pollution (Barking, Essex : 1987)》1993,82(3):245-253
Newark Bay, New Jersey, is particularly vulnerable to ecological damage from petroleum and chemical spills, as a result of the enclosed nature and shallow depth of the bay, the high frequency of shipping traffic, and the numerous chemical and petroleum transfer terminals located alongs its shores. To evaluate the potential impacts to the natural resources of this coastal estuarine ecosystem, chemical and petroleum accidents reported to the US Coast Guard (USCG) between 1982 and 1991 were compiled to determine the frequency and volume of these incidents in Newark Bay and in each of its major tributaries. Records obtained from the USCG National Response Center's computerized database indicated that more than 1453 accidental incidents, resulting in the release of more than 18 million US gallons of hazardous materials and petroleum products, occurred throughout Newark Bay during this period of time. The bulk of the materials released to the aquatic environment consisted of petroleum products, specifically No. 6 Fuel Oil (103 spills, 12 829 272 US gal) and gasoline (207 spills, 48 816 US gal). The majority of the reported incidents occurred in the Arthur Kill and its tributaries, as well as in the Kill Van Kull and the Passaic River. The results of this study indicated that the accidental discharge of petroleum and hazardous chemicals represents a significant source of chemical pollution in Newark Bay. Based on the frequency of spills and the volume of materials released to the aquatic environment, it is likely that these events are having a deleterious effect on the Newark Bay ecosystem. 相似文献
202.
203.
204.
Following earlier work (Al-Omran & Preston, 1987) in which phthalate ester speciation was examined in laboratory studies, the present paper describes the results of an attempt to validate the results by field measurements in the River Mersey Estuary, Liverpool, UK. Samples of water, suspended solids and sediments were analysed for their phthalate ester content. Solid samples were also analysed for their carbon, organic carbon and lipid content. A comparison of the field and laboratory results confirms the association between diethylhexyl phthalate and small particles and shows that other phthalates tend to be associated with relatively coarse, lipid-rich particles. Partition coefficients between dissolved phthalate esters and suspended particles are calculated and compared with other laboratory studies. 相似文献
205.
Steubing L Fangmeier A Both R Frankenfeld M 《Environmental pollution (Barking, Essex : 1987)》1989,58(4):281-302
The native ground vegetation of a beech forest was fumigated with moderate doses of SO(2), NO(2), and O(3) in open-top chambers. The effects of fumigants on growth and above-ground development were dependent on species. The treatments caused early senescence in several of the species present. The epicuticular waxes were attacked by fumigation, which was shown by higher wettability of the leaf surfaces and by leaching of ions. Interspecific differences were observed in the responses of transpiration and photosynthesis to fumigation. Similar patterns of effects on transpiration and photosynthesis, however, were found in the same species. Carbohydrate metabolism was altered by fumigation, leading to starch accumulation in the leaves. Besides effects on higher plants, fumigations also resulted in alterations of the soil microflora. The bacteria/fungi ratio was depressed at the fumigation plots. 相似文献
206.
The toxicity of an organotin pesticide, triphenyltin hydroxide, was assessed with several freshwater cladoceran species. Daphnia pulex, Daphnia magna, and Ceriodaphnia dubia were exposed for 48 h to triphenyltin hydroxide in static acute toxicity tests. Values of the 48-h trimmed Spearman-Karber EC(50)s for the three species were found to be 14.5, 16.5, and 11.3 microg litre(-1), respectively. Analysis of variance performed on EC(50) values of replicates revealed no significant differences between the three species. Methods were employed which decrease animal handling stress and increase the accuracy and precision of the concentrations. 相似文献
207.
208.
J. Langner L. Robertson C. Persson A. Ullerstig 《Atmospheric environment (Oxford, England : 1994)》1998,32(24):3949
The Eulerian atmospheric tracer transport model MATCH (Multiscale Atmospheric Transport and Chemistry model) has been extended with a Lagrangian particle model treating the initial dispersion of pollutants from point sources. The model has been implemented at the Swedish Meteorological and Hydrological Institute in an emergency response system for nuclear accidents and can be activated on short notice to provide forecast concentration and deposition fields.The model has been used to simulate the transport of the inert tracer released during the ETEX experiment and the transport and deposition of 137Cs from the Chernobyl accident. Visual inspection of the results as well as statistical analysis shows that the extent, time of arrival and duration of the tracer cloud, is in good agreement with the observations for both cases, with a tendency towards over-prediction for the first ETEX release. For the Chernobyl case the simulated deposition pattern over Scandinavia and over Europe as a whole agrees with observations when observed precipitation is used in the simulation. When model calculated precipitation is used, the quality of the simulation is reduced significantly and the model fails to predict major features of the observed deposition field. 相似文献
209.
In surface waters, phosphorus (P) concentrations exceeding 0.05 mg liter(-1) may cause eutrophic conditions. This study was undertaken to measure total P concentrations in runoff and tile drainage waters from land receiving either inorganic fertilizer or anaerobically digested sewage sludge. Total P was measured in runoff and tile drainage waters during 2 years of sample collections from instrumented, large-scale lysimeters planted to corn (Zea mays L.). During the 3 years prior to monitoring P concentrations, six of the lysimeter plots had been amended with anaerobically digested sewage sludge which supplied 5033 kg P per ha. Additional sludge applications supplied 1058 and 1989 kg P per ha during the first and second years of monitoring operations, respectively. Another six lysimeters were annually treated with fertilizer which included P applications amounting to 112 kg ha(-1). For years 1 and 2, respectively, annual losses from lysimeters treated with sewage sludge were 4.27 and 0.35 kg P per ha in runoff and 0.91 from 0.91 and 0.51 kg Per P per ha in drainage waters. Parallel annual losses of P from lysimeters treated with superphosphate were 2.15 and 0.17 kg ha(-1) in runoff and 0.53 and 0.35 kg ha(-1) in tile drainage waters. Sludge applications did not significantly change absolute soil contents of organic P, but did decrease the per cent of total P present in organic forms. Sludge and soil, respectively, contained 21 and 36% of their total P contents in organic forms. In sludge and soil about 85 and 64% of their respective total inorganic P contents were associated with the Al and Fe fractions. Sludge applications significantly increased soil contents of P in the saloid (water-soluble plus P extracted with 1 N NH(4)Cl), Al, Fe and reductant soluble P fractions, but contents of Ca-bound P were not changed. Total P contents of the soil below a depth of 30 cm were not affected by sludge incorporated to a depth of about 15 cm by plowing. 相似文献
210.
Blank LW Payer HD Pfirrmann T Gnatz G Kloos M Runkel KH Schmolke W Strube D Rehfuess KE 《Environmental pollution (Barking, Essex : 1987)》1990,64(3-4):189-207
This paper introduces a series of publications referring to a single 14-month laboratory study testing the hypothesis that the recent decline of Norway spruce (Picea abies (L.) Karst.) at higher elevations of the Bavarian Forest and comparable forests in medium-range mountains and in the calcareous Alps is caused by an interaction of elevated ozone concentrations, acid mist and site-specific soil (nutritional) characteristics. The effect of climatic extremes, a further important factor, was not included as an experimental variable but was considered by testing of the frost resistance of the experimental plants. Results of these individual studies are presented and discussed in the following 14 papers. Plants from six pre-selected clones of 3-year-old Norway spruce (Picea abies (L.) Karst.) were planted in April 1985 in an acidic soil from the Bavarian Forest, or a calcareous soil from the Bavarian Alps. After a transition period, plants were transferred, in July 1986, into four large environmental chambers and exposed for 14 months to an artificial climate and air pollutant regime based on long-term monitoring in the Inner Bavarian Forest. The climatic exposure protocol followed realistic seasonal and diurnal cycles (summer maximum temperature, 26 degrees C; total mean temperature, 9.8 degrees C; winter minimum, -14 degrees C; mean relative humidity, 70%; maximum irradiance, 500 W m(-2); daylength summer maximum, 17 h; winter minimum, 8 h). Plants were fumigated with ozone, generated from pure oxygen (control: annual mean of 50 microg m(-3); pollution treatment: annual mean of 100 microg m(-3) with 68 episodes of 130-360 microg m(-3) lasting 4-24 h), and background concentrations of SO(2) (22 microg m(-3)) and NO(2) (20 microg m(-3)); windspeed was set at a constant 0.6 m s(-1). Plants were additionally exposed to prolonged episodes of misting at pH 5.6 (control) and pH 3.0 (treatment). Simulation of the target climatic and fumigation conditions was highly reliable and reproducible (temperature +/-0.5 degrees C; rh+/-10%; ozone+/-10 microg m(-3);SO(2) and NO(2)+/-15 microg m(-3)). 相似文献