首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   523篇
  免费   2篇
  国内免费   26篇
安全科学   44篇
废物处理   30篇
环保管理   40篇
综合类   103篇
基础理论   69篇
污染及防治   175篇
评价与监测   56篇
社会与环境   31篇
灾害及防治   3篇
  2023年   10篇
  2022年   16篇
  2021年   16篇
  2020年   10篇
  2019年   16篇
  2018年   14篇
  2017年   9篇
  2016年   29篇
  2015年   20篇
  2014年   23篇
  2013年   41篇
  2012年   28篇
  2011年   40篇
  2010年   35篇
  2009年   37篇
  2008年   36篇
  2007年   21篇
  2006年   24篇
  2005年   17篇
  2004年   20篇
  2003年   23篇
  2002年   12篇
  2001年   4篇
  2000年   1篇
  1999年   3篇
  1998年   3篇
  1997年   4篇
  1996年   3篇
  1995年   1篇
  1994年   5篇
  1993年   3篇
  1992年   4篇
  1991年   2篇
  1990年   2篇
  1989年   1篇
  1988年   1篇
  1986年   4篇
  1985年   3篇
  1983年   3篇
  1982年   2篇
  1981年   1篇
  1980年   1篇
  1979年   1篇
  1970年   1篇
  1964年   1篇
排序方式: 共有551条查询结果,搜索用时 15 毫秒
161.
162.
This study assesses the relative dominance of vision and hearing in judgments of environments, and examines whether the sound sensitivity of the judge alters relative sensory dominance. Six sets of four composite (auditory-plus-visual) videotaped environmental displays were created from unisensory visual and auditory components with known levels of evoked affect. These displays, in a 2 (high, low) × 2 (high, low) Pleasure and/or Arousal format, were presented to 70 participants. The results indicate that visual cues dominate auditory cues in judgments of Pleasure, but that the degree of dominance is highly variable. Arousal judgments were not consistently related to visual or auditory cues. Sound sensitivity does not appear to influence the relative dominance of vision.  相似文献   
163.
The paper presents the results of studies on selecting a solid sorption material for absorbing liquid crop protection agents which permeate samples of protective clothing fabrics. The sorption materials were investigated and selected with an assumption that they should have a high recovery coefficient for biologically active substances, used as active ingredients in crop protection agents, at a presumed, acceptably high level. The selected substances were determined with a gas chromatograph equipped with an electron capture detector (dichlorvos, cypermethrin and 2,4-D) and a nitrogen-phosphorus detector (carbofuran). The tests demonstrated that polypropylene melt-blown type unwoven cloth had high recovery coefficients for all 4 active ingredients proposed for the study. The highest recovery coefficient, -.97, was obtained for carbofuran. The recovery coefficients obtained for the 3 remaining substances were lower: .89 for cypermethrin and 2,4-D, and .84 for dichlorvos.  相似文献   
164.
Equilibrium studies for the sorption of lead from effluents using chitosan   总被引:2,自引:0,他引:2  
Ng JC  Cheung WH  McKay G 《Chemosphere》2003,52(6):1021-1030
The sorption of lead ions from aqueous solution onto chitosan has been studied. Equilibrium studies have been carried out to determine the capacity of chitosan for lead ions. The effects of solution pH and chitosan particle size on the sorption capacity have been studied.The experimental data were analyzed using three equilibrium isotherm correlations, namely, Langmuir, Freundlich and Redlich-Peterson equations. The linear correlation coefficients were determined for each isotherm and the Freundlich provided the best fit. In addition, error functions have been used to determine the alternative single component equilibrium isotherm parameters by non-linear regression due to the inherent bias in using the correlation coefficient from the linearization. This technique enables the "best fit" isotherm parameters to be used in the equilibrium equations for the sorption of lead ions on chitosan within the limits and assumptions of the various error analysis methods.  相似文献   
165.
This study examined the levels of seven heavy metals (namelyzinc, copper, cadmium, chromium, lead, manganese and iron) andtheir associations with magnetic properties in playground dustof Hong Kong. Results showed that the playground dust containedhigh concentrations of Zn (mean = 1883 g g-1), Cu(mean = 143 g g-1) and Cr (mean = 263 g g-1).Qualitative examination of dust samples under microscope indicated local traffic as one of the important pollutant sources. Magnetic measurements indicated that these anthropogenicpollutants mainly consisted of coarse-grained multidomain (MD) ferrimagnetic minerals. Superparamagnetic (SP), stable single domain (SSD) ferrimagnetic grains and non-ferrimagnetic mineralswere present in relatively small amounts. Significant correlations between heavy metals and various magnetic parametersindicated a strong affinity of heavy metals to magnetic minerals hence pointed out the potential of magnetic properties for simpleand rapid proxy indications of heavy metal pollution in playground dust.  相似文献   
166.
167.
Material Disposal Area G is the primary low-levelradioactive waste disposal site at Los Alamos NationalLaboratory, New Mexico, and is adjacent to Pueblo of SanIldefonso lands. Pueblo residents and Los Alamos scientists areconcerned about radiological doses resulting from uptake of AreaG radionuclides by mule deer (Odocoileus hemionus) andRocky Mountain elk (Cervus elaphus), then consumption ofdeer and elk meat by humans. Tissue samples were collected fromdeer and elk accidentally killed near Area G and were analyzedfor 3H, 90Sr, total U, 238Pu, 239, 240Pu,241Am, and 137Cs. These data were used to estimatehuman doses based on meat consumption of 23 kg y-1. Humandoses were also modeled using RESRAD, and dose rates to deer andelk were estimated with a screening model. Dose estimates tohumans from tissue consumption were 2.9 × 10-3 mSv y-1and 1.6 × 10-3 mSv y-1 from deer and elk, respectively,and RESRAD dose estimates were of the same order of magnitude. Estimated dose rates to deer and elk were 2.1 × 10-4 mGyd-1 and 4.7 × 10-4 mGy d-1, respectively. Allestimated doses were significantly less than established exposurelimits or guidelines.  相似文献   
168.
Toxicity of some organic and inorganic chemicals to microorganisms is an important consideration in assessingtheir environmental impact against their economic benefits.Microorganisms play an important role in several environmentalprocesses, both natural and engineered. Some organic and inorganics at toxic levels have been detected in industrial discharges resulting in plant upsets and discharge permit violations. In addition to this, even though in some cases the effluent wastewater does not exceed the discharge limits,the results of toxicity tests show potential toxicity. Toxicityknowledge of effluents can benefit treatment plant operators inoptimising plant operation, setting pre-treatment standards, and protecting receiving water quality and in establishing sewer discharge permits to safeguard the plant. In the Turkish regulations only toxicity dilution factor (TDF) with fish is part of the toxicity monitoring program of permissible wastewater discharge. In various countries, laboratory studiesinvolving the use of different organisms and protocol for toxicity assessment was conducted involving a number of discharges.In this study, it was aimed to investigate the acute toxicity of textile and metal industry wastewaters by traditional and enrichment toxicity tests and emphasize the importance of toxicity tests in wastewater discharge regulations. The enrichment toxicity tests are novel applications and give anidea whether there is potential toxicity or growth limiting and stimulation conditions. Different organisms were used suchas bacteria (Floc and Coliform bacteria) algae (Chlorella sp.), fish (Lepistes sp.) and protozoan (Vorticella sp.) to represent four tropic levels. The textile industry results showed acute toxicity for at least one organism in 8 out of 23 effluent samples. Acute toxicity for at least two organisms in 7 out of 23 effluent sampling was observed for the metal industry. The toxicity test results were assessed with chemical analyses such as COD, BOD, color and heavy metals. It was observed that the toxicity of the effluents could not be explained by using physicochemical analyses in 5 cases for metal and 4 cases for the textile industries. The results clearly showed that the useof bioassay tests produce additional information about the toxicity potential of industrial discharges and effluents.  相似文献   
169.
This work was aimed at finding materials that could be used as alternatives to lichens as air quality monitors since the high natural variability and the large amount of lichen collected are two drawbacks of the use of these organisms. Lichen Flavoparmelia caperata(L.) Hale was exposed in three different forms (transplant, detached from the substratum and as a biomass-ground and homogeneized) and compared to the planetree bark (Platanus hybrida Brot.), exposed as a biomass, and two organic synthetic materials (Chelex(R) 100 resin and cellulose acetate). Materials were exposed for two months in the winter, spring and summer, at three Portuguese coastal cities. The results showed that the airborne accumulations of Cu, Ni, Pb and Sr were partially dependent on the meteorological conditions but mainly dependent on the nature of the exposed material. The standard deviations of the synthetic materials or homogenized biomass were the same or greater than lichen transplants or detached. The accumulation by biological materials, of the four studied elements, was comparable to the lichen transplant accumulation. The replacement of the traditional transplants by the biomass was not considered advantageous, since their preparation is time-consuming. Therefore lichens remain the most suitable in biomonitoring studies. The exposure of detached lichen allows the accurate measurement of the exposed area/volume so it can be useful to relate atmospheric deposition rates with the lichen metal content. The synthetic materials accumulated Cu and Ni and should only be used as an alternative to traditional transplants when these are the elements of interest.  相似文献   
170.
Environmental Science and Pollution Research - The use of composts and vermicomposts as adsorbents is an important topic of study in the field of environmental remediation. These materials are rich...  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号