全文获取类型
收费全文 | 104篇 |
免费 | 1篇 |
国内免费 | 1篇 |
专业分类
安全科学 | 1篇 |
废物处理 | 2篇 |
环保管理 | 23篇 |
综合类 | 6篇 |
基础理论 | 28篇 |
污染及防治 | 30篇 |
评价与监测 | 10篇 |
社会与环境 | 6篇 |
出版年
2023年 | 1篇 |
2019年 | 2篇 |
2016年 | 5篇 |
2015年 | 3篇 |
2014年 | 1篇 |
2013年 | 7篇 |
2012年 | 6篇 |
2011年 | 3篇 |
2010年 | 7篇 |
2009年 | 7篇 |
2008年 | 4篇 |
2007年 | 4篇 |
2006年 | 5篇 |
2005年 | 7篇 |
2004年 | 3篇 |
2003年 | 2篇 |
2002年 | 2篇 |
2001年 | 4篇 |
2000年 | 2篇 |
1999年 | 3篇 |
1998年 | 3篇 |
1997年 | 3篇 |
1996年 | 1篇 |
1994年 | 1篇 |
1992年 | 3篇 |
1991年 | 3篇 |
1990年 | 1篇 |
1987年 | 1篇 |
1985年 | 2篇 |
1982年 | 1篇 |
1980年 | 1篇 |
1977年 | 3篇 |
1976年 | 1篇 |
1972年 | 1篇 |
1971年 | 1篇 |
1967年 | 2篇 |
排序方式: 共有106条查询结果,搜索用时 15 毫秒
91.
Spatial and temporal variability of fish assemblages in Kuwait Bay was studied using the catch data acquired through monthly
otter trawl sampling from June 2002 through July 2004. We compared species composition using relative species density and
cluster analysis among different seasons (summer’02, summer’03, winter’03, and spring’04) and areas (center, south 1, south
2, west, north and east). Significant differences in total species, species richness (SR), diversity (H′), and fish abundance were tested among (between) different seasons and areas using analysis of variance (ANOVA) and Duncan’s
test. The results showed that the catches consisted of 80 species representing 41 families with Leiognathus bindus and Plicofollis tenuispinis dominating numerically. Spatially, species composition fell into three main areas: (1) east; (2) south 1 and south 2; and
(3) north, center, and west. Temporally, winter’03 and spring’04 were closely related, but we found low similarity between
the two summers and even lower similarity between the summers and other seasons, indicating high intra-annual variation. L. bindus was abundant in most of the areas except south 1, south 2 and the east area. Spatial changes of abundance of the two dominant
species showed a complementary trend. Where L. bindus was numerically high, P. tenuispinis was low, and vice versa. Significant lower total species number and SR were observed in south 2 than all the other areas
except the east, and significant higher fish abundance occurred in the summers than during the other seasons. Overall, it
was concluded that variation in fish assemblages was area dependent, while fish abundance was mainly influenced by seasonal
changes. 相似文献
92.
Genetic structure of populations of two species of Chthamalus (Crustacea: Cirripedia) in the north-east Atlantic and Mediterranean 总被引:2,自引:0,他引:2
Protein electrophoresis on starch gels was used to investigate population genetic structure of the barnacles Chthamalus
montagui
Southward and C. stellatus (Poli) over their north-east Atlantic and Mediterranean ranges. In each species, a single locus exhibited marked differentiation
of allele frequencies between Atlantic and Mediterranean localities; in C. stellatus, genetic differentiation between the two basins had not previously been noted. In both species, mean heterozygosity per locus
appeared higher in the Mediterranean samples than in the Atlantic, and Mediterranean populations had more alleles at the loci
studied. Possible explanations for the differentiation between the Atlantic and the Mediterranean populations are discussed.
Received: 30 May 1996 / Accepted: 17 September 1996 相似文献
93.
The critical load concept has become a valuable tool for policymakers in the European negotiations on emission reductions. Despite the international acceptance, ongoing validation of critical load methodology is of the utmost importance to avoid a situation where the calculation results are difficult to defend. In this paper we explore the potential of using the steady state soil chemistry model PROFILE as an alternative to the Steady State Water Chemistry (SSWC) method for calculating critical loads of acidity. The hypothesis is that the uncertainty in prediction of preindustrial leaching of base cations is reduced when soil properties instead of lake chemistry are used as input data. Paleolimnological reconstructions of preindustrial lake chemistry are used to test PROFILE. As PROFILE requires soil data that are not generally available on a catchment level, we used distributions of crucial parameters from soil survey data within the vicinity of five lakes for which paleoecological pH reconstructions were available. An important concern is the characterization of catchment hydrology. A calibration of the "effective" soil depth, needed to give PROFILE predictions that coincided with paleolimnology, suggested that approximately 0.6 m of the total soil depth was hydrologically active in supplying acid neutralizing capacity (ANC) to runoff through weathering. At present, there is insufficient evidence to either recommend or reject the PROFILE model for surface water critical loads. Before such a judgement can be made, the approach presented here has to be tested for other regions, and the definition of catchment hydrology needs to be investigated further. 相似文献
94.
Interactions of secondary amines with bentonite clay and humic materials in dilute aqueous systems 总被引:1,自引:0,他引:1
The speciation of dimethylamine, diethylamine, dibutylamine, and diethanolamine on bentonite clay saturated with 1) Na and Ca cations, 2) dodecyltrimethylammonium cation, and 3) tannic acid, and on humic acid and peat, has been studied. Adsorption isotherms were determined and the effect of ionic strength and pH on the adsorption were studied. The results show that the amines react with the particulates by ion exchange mechanisms. Hydrogen bonding seems to also contribute to the binding of dibutylamine. 相似文献
95.
96.
Jens Fölster Cecilia Andrén Kevin Bishop Ishi Buffam Neil Cory Willem Goedkoop Kerstin Holmgren Richard Johnson Hjalmar Laudon Anders Wilander 《Water, Air, & Soil Pollution: Focus》2007,7(1-3):331-338
The recovery from acidification has led to the demand for more precise criteria for classification of acidification. The Swedish Environmental Protection Agency has revised Sweden’s Ecological Quality Criteria for acidification to improve the correlation between the chemical acidification criteria and biological effects. This paper summarises the most relevant findings from several of the studies commissioned for this revision. The studies included data on water chemistry in 74 reference lakes in southern Sweden with data on fish in 61 of the lakes, as well as data on littoral fauna in 48 lakes. We found that the acidity variable most strongly correlated to the biota was the median pH from the current year. Our results probably do not reflect the mechanisms behind the negative effects of acidity on the biota, but are fully relevant for evaluation of monitoring data. The biogeochemical models used for predicting acidification reference conditions generate a pre-industrial buffering capacity. In order to get an ecologically more relevant criteria for acidification based on pH, we transferred the estimated change in buffering capacity into a corresponding change in pH. A change of 0.4 units was defined as the threshold for acidification. With this criterion a considerably lower number of Swedish lakes were classified as acidified when compared with the present Ecological Quality Criteria. 相似文献
97.
Bivalves demonstrate various morphological and behavioural adaptations to reduce the risk of being attacked by predators.
This paper examines how the presence of the crab Carcinus maenas (L.), a natural predator of the cockle Cerastoderma edule (L.), affects its burrowing depth and clearance or feeding rate. Cockles were placed in experimental tanks and treated with
three levels of predatory disturbance: (1) unfed crab loose inside the tank, (2) unfed crab inside a cage suspended in the
water column and (3) no crab present. Cockles’ burrowing depth was measured in two sediment types: mud and sand. Cockles burrowed
more deeply in treatments with no crabs. Burrowing depth in sand was significantly greater than in mud. Two factors may contribute
to the reduction in burial depth of C. edule in the presence of C. maenas: the change in the vertical orientation of the cockle and the ‘cough response’. No significant difference was found in the
cockles’ clearance rate among the different levels of predator threat. 相似文献
98.
Acidification of soils and surface waters caused by acid deposition is still a major problem in southern Scandinavia, despite
clear signs of recovery. Besides emission control, liming of lakes, streams, and wetlands is currently used to ameliorate
acidification in Sweden. An alternative strategy is forest soil liming to restore the acidified upland soils from which much
acidified runoff originates. This cost–benefit analysis compared these liming strategies with a special emphasis on the time
perspective for expected benefits. Benefits transfer was used to estimate use values for sport ffishing and nonuse values in terms of existence values. The results show that large-scale forest soil liming is not socioeconomically profitable, while
lake liming is, if it is done efficiently—in other words, if only acidified surface waters are treated. The beguiling logic
of “solving” an environmental problem at its source (soils), rather than continuing to treat the symptoms (surface waters),
is thus misleading. 相似文献
99.
This study analyses the relation of forest cover and stream flow on the 266 km2 Koga watershed in a headwater of Blue Nile Basin using both observed hydrological data and community perception. The watershed
declined from 16% forest cover in 1957 to 1% by 1986. The hydrological record did not reveal changes in the flow regime between
1960 and 2002 despite the reduction in forest area. This agrees with the perception of the downstream community living near
the gauging station. The upstream community, however, reported both decreases in low flows and increases in high flows shortly
after the forest cover was reduced. The upstream deforestation effect appeared to have been buffered by a wetland lower in
the watershed. This study concludes that community perception can be a complement to observational data for better understanding
how forest cover influences the flow regime. 相似文献
100.
R. Brooks M. McKenney-Easterling M. Brinson R. Rheinhardt K. Havens D. O’Brien J. Bishop J. Rubbo B. Armstrong J. Hite 《Environmental monitoring and assessment》2009,150(1-4):101-117
As part of a regional study by the Atlantic Slope Consortium (ASC) to develop ecological and socioeconomic indicators of aquatic ecosystem condition, we developed and tested a protocol for rapidly assessing condition of the stream, wetland, and riparian components of freshwater aquatic ecosystems. Aspects of hydrology, vegetation, in-stream and wetland characteristics, and on-site stressors were measured in the field. The resulting metrics were used to develop an index of overall condition, termed the Stream–Wetland–Riparian (SWR) Index. Values of this Index were compared to existing biotic indices and chemical measures, and to a Landscape Index created using satellite-based land cover data and a geographic information system (GIS). Comparisons were made at several levels of spatial aggregation and resolution, from site to small watershed. The SWR Index and associated Landscape Indices were shown to correlate highly with biological indicators of stream condition at the site level and for small contributing areas. The landscape patterns prevalent throughout the entire watershed do not necessarily match the patterns found adjacent to the stream network. We suggest a top-down approach that managers can use to sequentially apply these methods, to first prioritize watersheds based on a relative condition measure provided by the Landscape Index, and then assess condition and diagnose stressors of aquatic resources at the subwatershed and site level. 相似文献