全文获取类型
收费全文 | 219篇 |
免费 | 2篇 |
国内免费 | 2篇 |
专业分类
安全科学 | 4篇 |
废物处理 | 12篇 |
环保管理 | 26篇 |
综合类 | 30篇 |
基础理论 | 60篇 |
污染及防治 | 68篇 |
评价与监测 | 12篇 |
社会与环境 | 11篇 |
出版年
2023年 | 5篇 |
2022年 | 1篇 |
2021年 | 6篇 |
2020年 | 6篇 |
2019年 | 3篇 |
2018年 | 5篇 |
2017年 | 12篇 |
2016年 | 8篇 |
2015年 | 9篇 |
2014年 | 19篇 |
2013年 | 14篇 |
2012年 | 17篇 |
2011年 | 21篇 |
2010年 | 6篇 |
2009年 | 14篇 |
2008年 | 10篇 |
2007年 | 12篇 |
2006年 | 10篇 |
2005年 | 9篇 |
2004年 | 4篇 |
2003年 | 4篇 |
2002年 | 5篇 |
2000年 | 6篇 |
1999年 | 7篇 |
1997年 | 1篇 |
1996年 | 1篇 |
1995年 | 3篇 |
1994年 | 2篇 |
1978年 | 1篇 |
1976年 | 1篇 |
1975年 | 1篇 |
排序方式: 共有223条查询结果,搜索用时 15 毫秒
191.
Sebastian?Tro?ngEmail author Daniel?R.?Evans Emma?Harrison Cynthia?J.?Lagueux 《Marine Biology》2005,148(2):435-447
During 1955–2003, flipper tags were attached to 46,983 green turtles and ten turtles were fitted with satellite transmitters at Tortuguero, Costa Rica. Eight satellite-tracked turtles stayed within 135 km of the beach and probably returned to nest after release. The internesting area is more extensive than previously documented. Post-nesting migration routes of satellite-tracked turtles varied. Seven turtles swam close to the coast and three turtles swam through oceanic waters before moving toward nearshore areas. Sea surface height anomaly maps indicate that oceanic movements were consistent with the southwestern Caribbean gyre. Circling and semi-circling turtles could have been disoriented but submergence and surface times suggest they may have been feeding in Sargassum sp. concentrations. Rapid post-nesting migrations (mean 2.2 km hr−1) ended on benthic feeding grounds in shallow waters (<20 m) off Belize (n=1), Honduras (n=1) and Nicaragua (n=8). The spatial distribution of migration end points (n=10) and tag returns (n=4,669) are similar. Fishermen in Nicaragua target green turtles along migratory corridors and on foraging grounds. Management efforts are urgently needed in Nicaragua, particularly in the high-density feeding areas south and east of the Witties (N14°09 W82°45). The proximity of foraging grounds to the nesting beach (mean 512 km) may permit female turtles to invest more energy in reproduction and hence the Tortuguero population may have greater potential for recovery than other green turtle nesting populations. Recovery of the Tortuguero green turtle population will benefit countries and marine ecosystems throughout the Caribbean, especially Nicaragua. 相似文献
192.
Younis Bassam A. Jooß Yannik Spring Sebastian Weigand Bernhard 《Environmental Fluid Mechanics》2019,19(2):495-512
Environmental Fluid Mechanics - The paper reports on the development of an explicit, algebraic model for the turbulent scalar fluxes which properly reflects the dependence of these fluxes on the... 相似文献
193.
Muramic acid (MA) is a unique amino sugar that is a constituent of the peptidoglycan (PG) present in prokaryotic cell walls. MA can serve as a marker for quantifying bacterial load, e.g. in indoor environments, by using gas chromatography-tandem mass spectrometry (GC-MS-MS). We demonstrated recently that the methyl ester O-methyl acetate (MMA) derivative can be used to detect MA in house dust by ion-trap GC-MS-MS. However, since the MMA derivative is not formed from free MA quantification was not optimal. Here we report 1) significant improvements in sample preparation of the MMA derivative and 2) an evaluation of the performance of derivative, using for comparison the alditol acetate derivative, the gold standard in quantitative trace analysis of MA in complex matrices. The MMA derivative was analysed using an MS instrument with internal ionization and the alditol acetate derivative was analysed using an instrument with external ionization. 13C-labelled cyanobacteria, containing MA in their PG, were used as the internal standard. A linear relationship was found between the two methods in studies on 27 parallel samples of airborne dust from school classes collected on filters. Although the analytical sensitivity of the MMA derivatives was somewhat slightly lower than of the alditol acetate derivative, this may be due to differences in yield of derivative, sample clean-up efficiency, or different performance of the GC columns or MS instruments. However preparation of the MMA derivative is quick and compatible with preparation of methyl esters of 3-hydroxy fatty acids (used as markers of Gram negative endotoxin) allowing the levels of both markers to be determined in the same dust sample. In conclusion, the MMA procedure can be used to determine MA in environmental samples with good reproducibility provided the concentration of the 13C-labelled MA internal standard in the cyanobacteria is first determined with an alternative method. 相似文献
194.
Sorption and desorption of sulfadiazine in soil and soil-manure systems 总被引:10,自引:0,他引:10
Sulfadiazine is a widely used veterinary medicine that has high potential to enter the environment, especially the soil compartment by the application of manure on agricultural land and grass land or by the deposition of dung pats on pasture. Once it reaches the soil environments, it may enter into surface and ground water. Therefore, sorption-desorption behavior of sulfadiazine was studied under laboratory conditions in five different soils varying in their physicochemical properties. A batch equilibration technique was used with initial aqueous solution concentration of sulfadiazine at 5, 0.5, 0.05, and 0.005 microg mL(-1). Sorption-desorption data in soils with and without manure were well fitted with Freundlich model in log form (r(2), 0.99). A sorption-desorption hysteresis effect was apparent in all soils. A significant amount of sulfadiazine was found tightly bound to the soil particles and did not desorb after the desorption process. Moreover, presence of manure enhanced hysteresis effect. Hysteresis coefficient (H) value from soils in absence of manure (0.9-1.0) increased to the soils in presence of manure (0.9-1.8). Soils in the absence of manure showed low level of K(D Sorp.) values ranging from 0.1 to 24.3, suggesting low level sorption of sulfadiazine with appreciable risk of run-off and leaching, and in turn, surface and ground water contamination. However, presence of manure increased the sorption tendency of sulfadiazine significantly (K(D Sorp.), 6.9-40.2). K(D) values pertaining to desorption cycle increased from 1.2-90.4 to 10.4-167.3 in absence and presence of manure, respectively. 相似文献
195.
196.
Alina Pavel Edith Durisch-Kaiser Sorin Balan Silviu Radan Sebastian Sobek Bernhard Wehrli 《Environmental science and pollution research international》2009,16(Z1):86-91
Production of methane and carbon dioxide as well as methane concentrations in surface waters and emissions to the atmosphere
were investigated in two flow-through lake complexes (Uzlina–Isac and Puiu–Rosu–Rosulet) in the Danube Delta during post-flood
conditions in May and low water level in September 2006. Retained nutrients fuelled primary production and remineralisation
of bioavailable organic matter. This led to an observable net release of methane, particularly in the lakes Uzlina, Puiu and
Rosu in May. Input from the Danube River, from redbuds and benthic release contributed to CH4 concentrations in surface waters. In addition to significant river input of CO2, this trace gas was released via aerobic remineralisation within the water column and in top sediments. Emission patterns
of CO2 widely overlapped with those of CH4. Generally, greenhouse gas emissions peaked in the lake complex adjacent to the Danube River in May due to strong winds and
decreased with increasing hydrological distance from the Danube River. Intense remineralisation of organic matter in the Danube
Delta lakes results in a net source of atmospheric greenhouse gases. 相似文献
197.
Norman L. Miller Larry L. Dale Charles F. Brush Sebastian D. Vicuna Tariq N. Kadir Emin C. Dogrul Francis I. Chung 《Journal of the American Water Resources Association》2009,45(4):857-866
Abstract: A series of drought simulations were performed for the California Central Valley using computer applications developed by the California Department of Water Resources and historical datasets representing a range of droughts from mild to severe for time periods lasting up to 60 years. Land use, agricultural cropping patterns, and water demand were held fixed at the 2003 level and water supply was decreased by amounts ranging between 25 and 50%, representing light to severe drought types. Impacts were examined for four hydrologic subbasins, the Sacramento Basin, the San Joaquin Basin, the Tulare Basin, and the Eastside Drainage. Results suggest the greatest impacts are in the San Joaquin and Tulare Basins, regions that are heavily irrigated and are presently overdrafted in most years. Regional surface water diversions decrease by as much as 70%. Stream‐to‐aquifer flows and aquifer storage declines were proportional to drought severity. Most significant was the decline in ground water head for the severe drought cases, where results suggest that under these scenarios the water table is unlikely to recover within the 30‐year model‐simulated future. However, the overall response to such droughts is not as severe as anticipated and the Sacramento Basin may act as ground‐water insurance to sustain California during extended dry periods. 相似文献
198.
The elimination has been studied of racemic and enantioenriched metalaxyl applied as an emulsifiable concentrate and wettable powder combined with copper in a Cameroonian field site. The kinetics of the degradation/dissipation of metalaxyl and its acid metabolite were investigated using reversed phase HPLC-MS/MS, while the enantiomeric ratios were measured by HPLC-MS/MS using a Chiralcel OD-H HPLC column. Some soil enzymes activities were determined concurrently for 120d. The elimination of racemic metalaxyl was shown to be enantioselective, with the R-enantiomer being degraded more slowly than the S-enantiomer. Dissipation followed approximate square root first-order kinetics (R>0.98) without lag phases. The enantiomers of metalaxyl have different elimination rates, with half-lives ranging from only 0.8 to 1.5 days. After application to soil, the elimination of metalaxyl in the copper containing formulation was slower. The activities of acid phosphatase, alkaline phosphatase, and alkaline glucosidase were monitored throughout the experiments. No significant influence of metalaxyl and copper could be observed on these parameters. The significantly shorter half-life values of all forms of metalaxyl under field conditions, compared to the previously reported laboratory derived ones, may have implications for the plant disease control with these fungicides in tropical rainforest areas. 相似文献
199.
Heininger P Höss S Claus E Pelzer J Traunspurger W 《Environmental pollution (Barking, Essex : 1987)》2007,146(1):64-76
Nematode communities of eight sites from three river catchments were investigated in terms of the genera composition, feeding types, and life-history strategists. The sampling sites showed a gradient of anthropogenic contamination with heavy metals and organic pollutants being important factors in differentiating the sites. Nematode community structure was related to sediment pollution and the hydro-morphological structure of the sampling sites. Heavily contaminated sites were characterized by communities with high relative abundances of omnivorous and predacious nematodes (Tobrilus, c-p 3; Mononchus, c-p 4), while sites with low to medium contamination were dominated by bacterivorous nematodes (Monhystera, Daptonema; c-p 2) or suction feeders (Dorylaimus, c-p 4). The relatively high Maturity Index values in the heavily polluted sites were surprising. Nematodes turned out to be a suitable organism group for monitoring sediment quality, with generic composition being the most accurate indicator for assessing differences in nematode community structure. 相似文献
200.
Thorsten Stahl Sandy Falk Alice Rohrbeck Sebastian Georgii Christin Herzog Alexander Wiegand Svenja Hotz Bruce Boschek Holger Zorn Hubertus Brunn 《Environmental Sciences Europe》2017,29(1):19