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191.
Diffuse Nitrogen (N) loss from agriculture is a major factor contributing to increased concentrations of nitrate in surface
and groundwater, and of N2O and NH3 in the atmosphere. Different approaches to assess diffuse N losses from agriculture have been proposed, among other direct
measurements of N loads in leachate and groundwater, and physically-based modelling. However, both these approaches have serious
drawbacks and are awkward to use at a routine base. N loss indicators (NLIs) are environmental management tools for assessing
the risk of diffuse N losses from agricultural fields. They range in complexity from simple proxy variables to elaborate systems
of algebraic equations. Here we present an overview of NLIs developed in different parts of the world. NLIs can be categorized
into source-based, transport-based, and composite approaches. Several issues demand more attention in future studies. (1)
Is incorporation of leaching losses and gaseous losses into one single NLI warranted? (2) Is it sufficient to restrict the
focus on the rooted soil zone without considering the vadose zone and aquifer? (3) Calibration and validation of NLIs using
field data of N loss seems not sufficient. Comparisons of several different NLIs with each other needs more attention; however,
the different scaling of NLIs impedes comparability. (4) Sensitivity of input parameters with regard to the final NLI output
needs more attention in future studies. (5) For environmental management purposes, factors addressing management decision
by farmers deserve more attention. 相似文献
192.
193.
The antimicrobial agent triclosan (5-chloro-2-(2,4-dichlorophenoxy)phenol; TCS) is a member of a larger group of polychlorinated binuclear aromatic compounds frequently associated with adverse environmental and human health effects. Whereas the structure and function of TCS would suggest significant resistance to biotransformation, biological wastewater treatment currently is considered the principal destructive mechanism limiting dispersal of and environmental contamination with this compound. We explored the persistence of TCS in a typical full-scale activated sludge US sewage treatment plant using a mass balance approach in conjunction with isotope dilution liquid chromatography electrospray ionization mass spectrometry (ID-LC-ESI-MS) for accurate quantification. Average influent and effluent concentrations (mean +/- SD) of 4.7+/-1.6 and 0.07+/-0.06 microg 1(-1), respectively, revealed an apparent (liquid-phase) removal efficiency of 98+/-1%. However, further analyses demonstrated that the particle-active TCS (80+/-22% particle-associated in influent) was sequestered into wastewater residuals and accumulated in dewatered, digested sludge to concentrations of 30000+/-11000 microg kg-1. Overall, 50+/-19% (1640+/-610 g d-1) of the disinfectant mass entering the plant (3240+/-1860 g d-1) remained detectable in sludge, and less than half of the total mass (48+/-19%) was biotransformed or lost to other mechanisms. Thus, conventional sewage treatment was demonstrated to be much less effective in destroying the antimicrobial than the aqueous-phase removal efficiency of the plant would make believe. Furthermore, study findings indicate that the common practice of sludge recycling in agriculture results in the transfer of substantial quantities of TCS to US soils used, in part, for animal husbandry and crop production. 相似文献
194.
Ehrich Dorothée Schmidt Niels M. Gauthier Gilles Alisauskas Ray Angerbjörn Anders Clark Karin Ecke Frauke Eide Nina E. Framstad Erik Frandsen Jay Franke Alastair Gilg Olivier Giroux Marie-Andrée Henttonen Heikki Hörnfeldt Birger Ims Rolf A. Kataev Gennadiy D. Kharitonov Sergey P. Killengreen Siw T. Krebs Charles J. Lanctot Richard B. Lecomte Nicolas Menyushina Irina E. Morris Douglas W. Morrisson Guy Oksanen Lauri Oksanen Tarja Olofsson Johan Pokrovsky Ivan G. Popov Igor Yu. Reid Donald Roth James D. Saalfeld Sarah T. Samelius Gustaf Sittler Benoit Sleptsov Sergey M. Smith Paul A. Sokolov Aleksandr A. Sokolova Natalya A. Soloviev Mikhail Y. Solovyeva Diana V. 《Ambio》2020,49(3):801-804
Ambio - In the original published article, some of the symbols in figure 1A were modified incorrectly during the typesetting and publication process. The correct version of the figure is provided... 相似文献
195.
Participatory integrated assessment of adaptation to climate change in Alpine tourism and mountain agriculture 总被引:5,自引:0,他引:5
Winter tourism and mountain agriculture are the most important economic sectors in a major part of the Swiss Alps. Both are
highly sensitive to changing climatic conditions. In the framework of the CLEAR project, results from climate impact research
in the field of tourism and agricultural production were used to investigate the perception of climatic change by stakeholders
and to assess possible adaptations. We used a participatory integrated assessment (PIA) to involve the knowledge, values and
experiences of the various social actors in tourism and agriculture (e.g., skiers, tourism managers, farmers) in the research
process. Whereas climate change may have various severe direct impacts on the tourism industry, depending on the region, agricultural
production may generally benefit from changed climatic conditions. But because of the dependence of farmers on “off-farm”
income, the loss due to declining winter tourism in specific areas may cause more important indirect effects. However, the
two sectors may adapt actively by choosing from a variety of strategies, and the loss of income from the tourism industry
may support the re-evaluation of the various functions agriculture plays in mountain regions, beyond the production of food.
The study demonstrates the suitability of the PIA approach to elucidate the interactions between different stakeholders and
their perception of the climate change phenomena. A similar participatory approach could be a useful tool to transfer research
results and expert knowledge to the political process addressing adaptations to climate change.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
196.
In the northern hemisphere moose has been found to be suitable as a monitoring animal for the presence of cadmium in the environment. The metal accumulates mainly in the kidney and the liver, with the rate of accumulation dependent on age and possibly also on gender. Collection of tissue material often results in sample selections with disparate age and gender composition, which makes comparison between different regions and different studies difficult. A previous large scale investigation of metals in kidney and liver from moose in Sweden provided Cd data (n = 3,817 and 3,802, respectively) to further explore the relation between Cd accumulation and age/gender. Based on local averages, the individual deviations were analysed with respect to the factors age and gender resulting in an 'ageing function' for each gender and organ. In addition, estimates of the pure individual variations were obtained; the standard deviations correspond to a factor 1.7-1.9 for the Cd concentration, which indicates that 25-30 samples are needed to give a representative mean value (with RSD approximately 10%). In order to be able to compare results from different studies, all individual results can be transformed to represent a 'standard moose' with respect to age and gender. A comparison along these lines was undertaken between Cd levels in Alaska and Sweden. Finally, a relationship between the Cd levels in kidney and liver was derived, providing at least rough estimates for kidney from liver values (or vice versa). 相似文献
197.
This paper presents a spatially explicit bioeconomic analysis of species conservation in agricultural areas. Wild species in fragmented agricultural landscapes are best approached as metapopulations consisting of a finite number of local populations. Economic analysis of species conservation in fragmented habitat needs to deal with metapopulation theory and its theoretical implications. This paper presents a spatially explicit bioeconomic model consisting of a straightforward economic land use model and an applied metapopulation model. This paper demonstrates that multiple equilibria and multiple local optima in metapopulations might lead to nonconvexities in the production possibilities set of agricultural profits and species conservation. 相似文献
198.
René M Rossi Walter Bolli Rolf St?mpfli 《International journal of occupational safety and ergonomics》2008,14(1):55-60
Heat and mechanical protection properties of 6 fabric combinations commonly used in firefighters' protective clothing were assessed before and after different heat treatment. It was shown that after heat exposure, the values obtained were generally lower than in the original state. The mechanical properties of the materials were more affected by heat than by heat protective properties. In 2 cases, degradation started before a visible change in the material could be observed, which might be potentially dangerous for the end user who will not realize the alteration of the material. 相似文献
199.
200.
Teodor Velea Liliana Gherghe Vasile Predica Rolf Krebs 《Environmental science and pollution research international》2009,16(1):27-32