全文获取类型
收费全文 | 11886篇 |
免费 | 109篇 |
国内免费 | 89篇 |
专业分类
安全科学 | 336篇 |
废物处理 | 443篇 |
环保管理 | 1639篇 |
综合类 | 2116篇 |
基础理论 | 3129篇 |
环境理论 | 7篇 |
污染及防治 | 2970篇 |
评价与监测 | 735篇 |
社会与环境 | 624篇 |
灾害及防治 | 85篇 |
出版年
2022年 | 103篇 |
2021年 | 98篇 |
2020年 | 80篇 |
2019年 | 93篇 |
2018年 | 164篇 |
2017年 | 142篇 |
2016年 | 223篇 |
2015年 | 194篇 |
2014年 | 269篇 |
2013年 | 881篇 |
2012年 | 356篇 |
2011年 | 497篇 |
2010年 | 409篇 |
2009年 | 478篇 |
2008年 | 521篇 |
2007年 | 518篇 |
2006年 | 453篇 |
2005年 | 420篇 |
2004年 | 352篇 |
2003年 | 365篇 |
2002年 | 351篇 |
2001年 | 472篇 |
2000年 | 346篇 |
1999年 | 209篇 |
1998年 | 131篇 |
1997年 | 157篇 |
1996年 | 163篇 |
1995年 | 190篇 |
1994年 | 192篇 |
1993年 | 159篇 |
1992年 | 132篇 |
1991年 | 169篇 |
1990年 | 163篇 |
1989年 | 157篇 |
1988年 | 115篇 |
1987年 | 114篇 |
1986年 | 118篇 |
1985年 | 91篇 |
1984年 | 108篇 |
1983年 | 110篇 |
1982年 | 118篇 |
1981年 | 108篇 |
1980年 | 96篇 |
1979年 | 112篇 |
1978年 | 73篇 |
1977年 | 76篇 |
1975年 | 76篇 |
1973年 | 72篇 |
1972年 | 65篇 |
1967年 | 66篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Brominated flame retardants and organochlorines in the European environment using great tit eggs as a biomonitoring tool 总被引:1,自引:0,他引:1
Van den Steen E Pinxten R Jaspers VL Covaci A Barba E Carere C Cichoń M Dubiec A Eeva T Heeb P Kempenaers B Lifjeld JT Lubjuhn T Mänd R Massa B Nilsson JA Norte AC Orell M Podzemny P Sanz JJ Senar JC Soler JJ Sorace A Török J Visser ME Winkel W Eens M 《Environment international》2009,35(2):310-317
Large-scale studies are essential to assess the emission patterns and spatial distribution of organohalogenated pollutants (OHPs) in the environment. Bird eggs have several advantages compared to other environmental media which have previously been used to map the distribution of OHPs. In this study, large-scale geographical variation in the occurrence of OHPs, such as polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and organochlorine pesticides (OCPs), was investigated throughout Europe using eggs of a terrestrial residential passerine species, the great tit (Parus major). Great tit eggs from 22 sampling sites, involving urban, rural and remote areas, in 14 European countries were collected and analysed (5-8 eggs per sampling site). The environmentally most important congeners/compounds of the analysed pollutants were detectable in all sampling locations. For PCBs, PBDEs and OCPs, no clear geographical contamination pattern was found. Sum PCB levels ranged from 143 ng/g lipid weight (lw) to 3660 ng/g lw. As expected, PCB concentrations were significantly higher in the sampled urban compared to the remote locations. However, the urban locations did not show significantly higher concentrations compared to the rural locations. Sum PBDEs ranged from 4.0 ng/g lw to 136 ng/g lw. PBDEs were significantly higher in the urbanized sampling locations compared to the other locations. The significant, positive correlation between PCB and PBDE concentrations suggests similar spatial exposure and/or mechanisms of accumulation. Significantly higher levels of OCPs (sum OCPs ranging from 191 ng/g lw to 7830 ng/g lw) were detected in rural sampling locations. Contamination profiles of PCBs, PBDEs and OCPs differed also among the sampling locations, which may be due to local usage and contamination sources. The higher variance among sampling locations for the PCBs and OCPs, suggests that local contamination sources are more important for the PCBs and OCPs compared to the PBDEs. To our knowledge, this is the first study in which bird eggs were used as a monitoring tool for OHPs on such a large geographical scale. 相似文献
992.
S. Fesenko N. Isamov B.J. Howard N.A. Beresford C.L. Barnett N. Sanzharova G. Voigt 《Journal of environmental radioactivity》2009
Over 150 publications reporting studies conducted in the former USSR were reviewed to provide transfer coefficients (Ff) to the muscle of domestic animals from experiments using chronic administration, often for long timescales in large scale experiments. Only a few of these studies were made available in the English language literature or taken into account in international reviews. The values derived have been compared with expected values reported by the IAEA's Handbook of parameter values for the prediction of radionuclide transfer in temperate environments (TRS 364) where possible. The information presented here has been used in the current updating of parameters recommended for environmental assessments by the IAEA. Many of the reported values are for Sr due to the Mayak accident and Cs due to the Chernobyl accident. Nevertheless, the reported data for a wide range of radionuclides, in particular for Ru, Sb, and Zn markedly improve the extent of available data. 相似文献
993.
A compilation has been undertaken of data which can be used to derive animal product transfer coefficients for radionuclides, including an extensive review of Russian language information. The resultant database has been used to provide recommended transfer coefficient values for a range of radionuclides to (i) cow, sheep and goat milk, (ii) meat (muscle) of cattle, sheep, goats, pigs and poultry and (iii) eggs. The values are used in a new IAEA handbook on transfer parameters which replaces that referred to as ‘TRS 364’. The paper outlines the approaches and procedures used to identify and collate data, and assumptions used. There are notable differences between the TRS 364 ‘expected’ values and the recommended values in the revised Handbook from the new database. Of the recommended values, three milk values are at least an order of magnitude higher than the TRS 364 values (Cr, Pu (cow) Pu (sheep)) and one milk value is lower (Ni (cow)). For meat, four values (Am, Cd, Sb (beef) I (pork)) are at least an order of magnitude higher than the TRS 364 values and eight values are at least an order of magnitude lower (Ru, Pu (beef), Ru, Sr, Zn (sheep), Ru, Sr (pork), Mn (poultry)). Many data gaps remain. 相似文献
994.
A. Tieber H. Lettner P. Bossew A. Hubmer B. Sattler W. Hofmann 《Journal of environmental radioactivity》2009
Cryoconites are airborne sediments which accumulate on the surface of glaciers. In samples of cryoconites a temperate Austrian glacier high activity concentrations of anthropogenic radionuclides were found, which stem from global and Chernobyl fallouts. Radionuclides identified were 137Cs, 134Cs, 238Pu, 239+240Pu, 90Sr, 241Am, 60Co, 154Eu, 207Bi, and 125Sb. 相似文献
995.
Among all emerging substances in water, pharmaceutical products (PPs) and residues are a lot of concern. These last two years, the number of studies has increased drastically, however much less for water resources and drinking water than for wastewater. This literature review based on recent works, deals with water resources (surface or groundwater), focusing on characteristics, occurrence and fate of numerous PPs studied, and drinking water including water quality. Through this review, it appears that the pharmaceutical risk must be considered even in drinking water where concentrations are very low. Moreover, there is a lack of research for by-products (metabolites and transformation products) characterization, occurrence and fate in all water types and especially in drinking water. 相似文献
996.
Kurnaz A Kucukomeroglu B Damla N Cevik U 《Journal of environmental radioactivity》2011,102(4):393-399
The activity concentrations and absorbed gamma dose rates due to primordial radionuclides and 137Cs have been ascertained in 222 soil samples in 18 counties of the Trabzon province of Turkey using a HPGe detector. The mean activity concentrations of 238U, 232Th, 40K and 137Cs in soil samples were 41, 35, 437 and 21 Bq kg−1, respectively. Based on the measured concentrations of these radionuclides, the mean absorbed gamma dose in air was calculated as 59 nGy h−1 and hence, the mean annual effective dose due to terrestrial gamma radiation was calculated as 72 μSv y−1. In addition, outdoor in situ gamma dose rate (D) measurements were performed in the same 222 locations using a portable NaI detector and the annual effective dose was calculated to be 66 μSv y−1 from these results. The results presented in this study are compared with other parts of Turkey. Radiological maps of the Trabzon province were composed using the results obtained from the study. 相似文献
997.
Aerial measurement of radioxenon concentration off the west coast of Vancouver Island following the Fukushima reactor accident 总被引:1,自引:0,他引:1
Sinclair LE Seywerd HC Fortin R Carson JM Saull PR Coyle MJ Van Brabant RA Buckle JL Desjardins SM Hall RM 《Journal of environmental radioactivity》2011,102(11):1018-1023
In response to the Fukushima nuclear reactor accident, on March 20th, 2011, Natural Resources Canada conducted aerial radiation surveys over water just off the west coast of Vancouver Island. Dose-rate levels were found to be consistent with background radiation, however a clear signal due to 133Xe was observed. Methods to extract 133Xe count rates from the measured spectra, and to determine the corresponding 133Xe activity concentration, were developed. The measurements indicate that 133Xe concentrations on average lie in the range of 30-70 Bq/m3. 相似文献
998.
Fish advisories for polychlorinated biphenyls (total-PCBs) and mercury are often given on a length-specific basis and fish sex is usually not considered. The relationship between concentration and length is well established for mercury, however its suitability for total-PCBs and the influence of sex over the large scale covered by most monitoring programs is not well known. Here we use what is perhaps the largest consistent sport fish contaminant dataset to evaluate the relationship between total-PCB/mercury and length and sex. We evaluated seven of the most commonly consumed fishes from the Canadian Great Lakes and two Ontario (Canada) inland lakes. For mercury, the relationship between concentration and length was significant (p<0.05) in most fish species and locations. For total-PCB, this relationship was also generally significant in Chinook salmon and lake trout, which are the species with the most advisories for this compound. In contrast, significant relationships were found less often for whitefish, northern pike, smallmouth bass, walleye, and especially yellow perch. However, mercury usually drives fish consumption advisories for these species. Overall, our results support the protocol of issuing contaminant advice on a length-specific basis in fish monitoring programs with reasonable confidence when at least a moderate number of samples over the natural size range of a species are included in the analysis. Sex differences were common for walleye (males>females, p<0.05) but not other species, suggesting that an equal number of male and female walleye should be used in deriving fish advisories for walleye. 相似文献
999.
A. B. Savinov 《Russian Journal of Ecology》2011,42(3):179-185
According to the basic concept of the theory dealt with in this study, autocenosis, i.e., a self-regulatory host-symbiont system, rather than an individual, is the individual-level unit. Then, democenosis, which is a system of autocenoses, corresponds to the population level. Therefore, natural selection of autocenoses rather
than individuals occurs in a democenosis, and auto- and democenoses, rather than “individuals” and “populations,” are components
of food chains and webs. However, the symbiotic approach does not exclude the population paradigm and will be developed in
parallel with it. 相似文献
1000.
A. B. Martynenko 《Russian Journal of Ecology》2006,37(1):53-59
Species richness, taxonomic diversity, and qualitative composition of the butterfly fauna (Lepidoptera, Diurna) are discussed in the light of data on the altitudinal zonality of local faunas in the southern Far East and Transbaikalia. It is shown that qualitative elevation-dependent changes in the fauna occur only in the western and northern parts of the region. 相似文献