全文获取类型
收费全文 | 2427篇 |
免费 | 11篇 |
国内免费 | 5篇 |
专业分类
安全科学 | 42篇 |
废物处理 | 87篇 |
环保管理 | 142篇 |
综合类 | 758篇 |
基础理论 | 430篇 |
环境理论 | 7篇 |
污染及防治 | 731篇 |
评价与监测 | 136篇 |
社会与环境 | 104篇 |
灾害及防治 | 6篇 |
出版年
2022年 | 36篇 |
2021年 | 31篇 |
2020年 | 18篇 |
2019年 | 22篇 |
2018年 | 55篇 |
2017年 | 57篇 |
2016年 | 77篇 |
2015年 | 43篇 |
2014年 | 89篇 |
2013年 | 145篇 |
2012年 | 66篇 |
2011年 | 123篇 |
2010年 | 77篇 |
2009年 | 82篇 |
2008年 | 119篇 |
2007年 | 110篇 |
2006年 | 92篇 |
2005年 | 87篇 |
2004年 | 63篇 |
2003年 | 58篇 |
2002年 | 61篇 |
2001年 | 63篇 |
2000年 | 40篇 |
1999年 | 32篇 |
1998年 | 20篇 |
1997年 | 21篇 |
1996年 | 18篇 |
1995年 | 21篇 |
1994年 | 34篇 |
1993年 | 15篇 |
1992年 | 14篇 |
1991年 | 15篇 |
1989年 | 13篇 |
1984年 | 14篇 |
1981年 | 17篇 |
1969年 | 14篇 |
1968年 | 13篇 |
1967年 | 16篇 |
1966年 | 24篇 |
1965年 | 29篇 |
1964年 | 18篇 |
1963年 | 26篇 |
1962年 | 23篇 |
1961年 | 31篇 |
1960年 | 21篇 |
1959年 | 21篇 |
1958年 | 14篇 |
1957年 | 25篇 |
1956年 | 16篇 |
1955年 | 16篇 |
排序方式: 共有2443条查询结果,搜索用时 31 毫秒
1.
2.
Frank Eierdanz Joseph Alcamo Lilibeth Acosta-Michlik Dörthe Krömker Dennis Tänzler 《Regional Environmental Change》2008,8(4):197-205
This paper presents the technical aspects of a new methodology for assessing the susceptibility of society to drought. The
methodology consists of a combination of inference modelling and fuzzy logic applications. Four steps are followed: (1) model
input variables are selected—these variables reflect the main factors influencing susceptibility in a social group, population
or region, (2) fuzzification—the uncertainties of the input variables are made explicit by representing them as ‘fuzzy membership
functions’, (3) inference modelling—the input variables are used to construct a model made up of linguistic rules, and (4)
defuzzification—results from the model in linguistic form are translated into numerical form, also through the use of fuzzy
membership functions. The disadvantages and advantages of this methodology became apparent when it was applied to the assessment
of susceptibility from three disciplinary perspectives: Disadvantages include the difficulty in validating results and the
subjectivity involved with specifying fuzzy membership functions and the rules of the inference model. Advantages of the methodology
are its transparency, because all model assumptions have to be made explicit in the form of inference rules; its flexibility,
in that informal and expert knowledge can be incorporated through ‘fuzzy membership functions’ and through the rules in the
inference model; and its versatility, since numerical data can be converted to linguistic statements and vice versa through
the procedures of ‘fuzzification’ and ‘defuzzification’. 相似文献
3.
S. S. S. Sarma Saúl Avelino Rivera Fabiola Elizalde Hinojosa S. Nandini 《Russian Journal of Ecology》2007,38(5):353-362
We tested separately the effect of two taxonomically related rotifers (B. patulus and B. macracanthus) on the population dynamics of another species (A. fissa) at low (0.5 ×10 6) and high food levels (1.5 × 106 cells/ml of Chlorella vulgaris) using different inoculation densities (0–100%). We also quantified the impact of A. fissa on the two brachionid species. Regardless of the presence of the competing species, an increase in the availability of food
led to increase in the abundances of the three rotifers. The population growth of B. patulus, B. macracanthus, or A. fissa was affected negatively when cultured together with another species. An increase in the initial density of any one of the
competing species became advantageous to maintain a certain population size. At a low algal food level, B. patulus was able to suppress A. fissa more strongly than B. macracanthus. On the other hand, at a high food level, B. macracanthus suppressed the population of A. fissa more strongly than B. patulus. Peak population densities for A. fissa varied from about 150 to 1000 ind./ml, depending on food density and the presence of competitors. The rate of population
increase (r) of A. fissa, B. patulus, and B. macracanthus increased with an increase in food availability but decreased with increasing initial density of the competitor. Both Brachionus spp. experienced negative growth rates in the presence of A. fissa, especially at a high initial density of the latter.
Published in Russian in Ekologiya, 2007, Vol. 38, No. 5, pp. 381–390.
The article was submitted by the authors in English. 相似文献
4.
Cornus stolonifera, Salix petiolaris, and Spiraea alba
clones already located within the corridor of an electrical power line. To
establish the efficiency of treatments, we examined the statistical
differences of growth traits between species and treatments.
An analysis of the effects of layering shows, after the first growth season,
differences for all growth traits in only one species, Spiraea alba.
After the second growth season, we observed the development of new aerial
stems. Layering favors horizontal expansion of shrubs over height
development. The third year after treatment, the effect of layering is
reduced except for Cornus stolonifera, which continuously increases,
as shown by the significant progression of the clone issued from the layer
even five years after treatments. With the cutting back technique, we
expected a distinct vertical growth of the shrubs at the expense of
increasing the crown diameter. This technique would be best associated with
the rejuvenation of clones, followed by a layering of new shoots to allow a
horizontal expansion of the shrubs. Therefore, the formation of a dense shrub
community by layering should be considered a valuable approach for the
biological control of undesirable trees in powerline rights-of-way. 相似文献
5.
6.
7.
Three simple steady-state water-chemistry models are used to calculate critical loads of sulfur for lakes in Finland. Because of the high concentrations of organic matter in Finnish lakes, the influence of organic anions on the calculation of critical loads has been given special attention. The first two methods are well known ion-balance methods which have been used in many previous lake-acidification studies. The third method, developed for this study, includes the numerical solution of equilibrium equations for organic anions, inorganic carbon species and inorganic monomeric aluminum. The original pH and aluminum concentration of the lakes are estimated with this model, and a method to estimate the original acid neutralizing capacity (ANC) by simulating a Gran-titration is also tested on the lake data. Uncertainty in the predictions is estimated by varying the most critical model parameters. 相似文献
8.
Pleijel H Skärby L Wallin G Selldén G 《Environmental pollution (Barking, Essex : 1987)》1991,69(2-3):151-168
Spring wheat (Triticum aestivum L., cv. Drabant) was exposed to different concentrations of ozone in open-top chambers for two growing seasons, 1987 and 1988, at a site located in south-west Sweden. The chambers were placed in a field of commercially grown spring wheat. The treatments were charcoal-filtered air (CF), non-filtered air (NF) and non-filtered air plus extra ozone (NF(+)). In 1988, one additional ozone concentration (NF(++)) was used. Grain yield was affected by the ozone concentration of the air. Air filtration resulted in an increase in grain yield of about 7% in both years, compared to NF. The addition of ozone (NF(+), NF(++)) reduced grain yield and increased the content of crude protein of the grain in both years. Filtration of the air had no significant effect on the content of crude protein, compared to NF. The results showed a strong positive chamber effect on grain yield in the cold and wet summer of 1987. In 1988, there was no net chamber effect on grain yield. The relative differences between the CF, NF and NF(+) treatments with respect to grain yield were of the same magnitude in the two years, despite the very different weather conditions. 相似文献
9.
Givelet N Le Roux G Cheburkin A Chen B Frank J Goodsite ME Kempter H Krachler M Noernberg T Rausch N Rheinberger S Roos-Barraclough F Sapkota A Scholz C Shotyk W 《Journal of environmental monitoring : JEM》2004,6(5):481-492
For detailed reconstructions of atmospheric metal deposition using peat cores from bogs, a comprehensive protocol for working with peat cores is proposed. The first step is to locate and determine suitable sampling sites in accordance with the principal goal of the study, the period of time of interest and the precision required. Using the state of the art procedures and field equipment, peat cores are collected in such a way as to provide high quality records for paleoenvironmental study. Pertinent field observations gathered during the fieldwork are recorded in a field report. Cores are kept frozen at -18 degree C until they can be prepared in the laboratory. Frozen peat cores are precisely cut into 1 cm slices using a stainless steel band saw with stainless steel blades. The outside edges of each slice are removed using a titanium knife to avoid any possible contamination which might have occurred during the sampling and handling stage. Each slice is split, with one-half kept frozen for future studies (archived), and the other half further subdivided for physical, chemical, and mineralogical analyses. Physical parameters such as ash and water contents, the bulk density and the degree of decomposition of the peat are determined using established methods. A subsample is dried overnight at 105 degree C in a drying oven and milled in a centrifugal mill with titanium sieve. Prior to any expensive and time consuming chemical procedures and analyses, the resulting powdered samples, after manual homogenisation, are measured for more than twenty-two major and trace elements using non-destructive X-Ray fluorescence (XRF) methods. This approach provides lots of valuable geochemical data which documents the natural geochemical processes which occur in the peat profiles and their possible effect on the trace metal profiles. The development, evaluation and use of peat cores from bogs as archives of high-resolution records of atmospheric deposition of mineral dust and trace elements have led to the development of many analytical procedures which now permit the measurement of a wide range of elements in peat samples such as lead and lead isotope ratios, mercury, arsenic, antimony, silver, molybdenum, thorium, uranium, rare earth elements. Radiometric methods (the carbon bomb pulse of (14)C, (210)Pb and conventional (14)C dating) are combined to allow reliable age-depth models to be reconstructed for each peat profile. 相似文献
10.
One-year monitoring survey of organic compounds (PAHs, PCBs, TBT), heavy metals and biomarkers in blue mussels from the Arcachon Bay, France 总被引:2,自引:0,他引:2
Devier MH Augagneur S Budzinski H Le Menach K Mora P Narbonne JF Garrigues P 《Journal of environmental monitoring : JEM》2005,7(3):224-240
Marine mussels Mytilus sp. were transplanted on a monthly basis in cages over one year to oyster farms and harbours in the Arcachon Bay (France) in order to assess the water quality of the bay. Contaminant levels (organotin compounds, trace metals, PCBs and PAHs) were measured in tissues of transplanted mussels and mussels from a reference station, along with physiological parameters of the mussels (condition indexes, lipid content and dry weight). Four biomarkers (AChE: acetylcholinesterase activity, GST: gluthathione S-transferase activity, CAT: catalase activity and TBARS: thiobarbituric acid-reactive substance content) were also monitored. The remote stations monitored (oyster parks) exhibited no accumulation pattern of pollutants. Their respective concentrations therefore constitute a background level of the contamination in the bay ([TBT]= 30 ng Sn g(-1) dw, [SigmaHAPs]= 100 ng g(-1) dw, [SigmaPCBs]= 35 ng g(-1) dw). The elevated chemical contamination of the largest harbour of the bay, the Arcachon harbour, can be interpreted in terms of persistence of organotin compounds ([SigmaOTs]= 1500-2000 ng Sn g(-1) dw) and PAHs ([SigmaHAPs]= 4500-5000 ng g(-1) dw) in sediments and, to a lesser extent, of direct inputs of copper ([Cu]= 20 microg g(-1) dw in harbours versus 7 in oyster parks) and petrogenic PAHs ([methylphenanthrenes]= 1600 ng g(-1) dw in the dockyard versus 170 at the gas stations), related to the use of copper-based antifouling paints and to dockyard activity, respectively. However, the Arcachon Bay presents a low contamination level by PCBs and metals, including harbour stations. Furthermore, higher levels of other PAHs (particularly alkyl PAHs such as methylphenanthrenes/1600 ng g(-1) dw) not included in the 16 PAHs from the EPA priority list (usually studied in biomonitoring programmes/1500 ng g(-1) dw) in the Arcachon harbour underline the need to integrate these compounds in biomonitoring of highly PAH-polluted areas such as harbours in order to avoid misinterpretation of the biological responses observed. Biomarker responses were not able to discriminate the different chemical contamination levels recorded in the Arcachon Bay and rather reflected changes in environmental factors. Furthermore, the strong intraspecies variability of biological responses could be due to genetic differences of mussels from the Arcachon Bay. It is the first time that such an integrated monitoring is performed in the Arcachon Bay, also taking into account seasonal variations of chemical contents and biomarkers levels in mussel tissues. 相似文献