全文获取类型
收费全文 | 1226篇 |
免费 | 74篇 |
国内免费 | 448篇 |
专业分类
安全科学 | 60篇 |
废物处理 | 86篇 |
环保管理 | 100篇 |
综合类 | 650篇 |
基础理论 | 226篇 |
污染及防治 | 467篇 |
评价与监测 | 73篇 |
社会与环境 | 48篇 |
灾害及防治 | 38篇 |
出版年
2024年 | 3篇 |
2023年 | 12篇 |
2022年 | 52篇 |
2021年 | 48篇 |
2020年 | 35篇 |
2019年 | 51篇 |
2018年 | 42篇 |
2017年 | 57篇 |
2016年 | 53篇 |
2015年 | 90篇 |
2014年 | 105篇 |
2013年 | 131篇 |
2012年 | 112篇 |
2011年 | 99篇 |
2010年 | 84篇 |
2009年 | 76篇 |
2008年 | 111篇 |
2007年 | 83篇 |
2006年 | 63篇 |
2005年 | 57篇 |
2004年 | 51篇 |
2003年 | 47篇 |
2002年 | 39篇 |
2001年 | 29篇 |
2000年 | 26篇 |
1999年 | 31篇 |
1998年 | 27篇 |
1997年 | 22篇 |
1996年 | 24篇 |
1995年 | 16篇 |
1994年 | 13篇 |
1993年 | 14篇 |
1992年 | 12篇 |
1991年 | 9篇 |
1990年 | 4篇 |
1989年 | 2篇 |
1988年 | 5篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1985年 | 3篇 |
1983年 | 3篇 |
1982年 | 1篇 |
1981年 | 2篇 |
1977年 | 1篇 |
1956年 | 1篇 |
排序方式: 共有1748条查询结果,搜索用时 781 毫秒
901.
René Prior Moritz Mittelbach Dominik Begerow 《Journal of environmental science and health. Part. B》2017,52(6):376-386
In this study, the impacts of three different fungicides to fungal phyllosphere communities on broad bean (Vicia faba, Fabaceae) and common bean (Phaseolus vulgaris, Fabaceae) were analyzed. The fungicides included copper, sulfur, and azoxystrobin. The plants were sowed, grown, and treated under conditions occurring in conventional and organic farming. A culture-based approach was used to identify changes in the phyllosphere fungal community after the treatment. Different effects on species richness and growth index of the epiphytic and endophytic communities for common bean and broad bean could be shown. Treatments with sulfur showed the weakest effect, followed by those based on copper and the systemic azoxystrobin, which showed the strongest effect especially on endophytic communities. The epiphytic fungal community took five weeks to recover after treatment with azoxystrobin. However, the effect of azoxystrobin on the endophytic community lasted more than five weeks. Finally, the data suggest that the surface structure of the host leaves have a huge impact on the mode of action that the fungicides exert. 相似文献
902.
1 标准任务的来源
根据2016年强制性标准整合精简结论,对GB21148-2007《个体防护装备安全鞋》、GB 21147-2007《个体防护装备防护鞋》、GB 21146-2007《个体防护装备职业鞋》、GB 12011-2009《足部防护电绝缘鞋》4项标准提出整合修订,并继续作为强制性标准执行.
2017年12月... 相似文献
903.
Base-catalyzed dehydrochlorination of alpha-, beta-, and gamma-hexachlorocyclohexane (HCH) was examined at different pH and temperature conditions. No reaction was observed for beta-HCH under all tested conditions likely due to the fact that all chlorines are at the equatorial positions. Highly pH- and temperature-dependent reaction rates were observed for alpha- and gamma-HCH, and pentachlorocyclohexenes (PCCHs) and 1,2,4- and 1,2,3-trichlorobenzene (TCB) were detected as the intermediates and final products of the transformation of both alpha- and gamma-HCH. The pseudo-first-order rate constants of each step of the reactions were calculated at different T and pH conditions. For the first step, the rate constants were at approximately 0.0005 d-1 in solutions below pH 7.0, and increased by about an order of magnitude per pH unit from pH 7.01 to pH 12.02. The second-order reaction rate constants (kb) of this step were 3.57+/-0.03 and 3.19+/-0.19 M-1 d-1, respectively, and the associated activation energies (Ea) at pH 9.26 were 60.4+/-7.8 and 67.7+/-8.7 kJ mol-1, respectively, for alpha- and gamma-HCH. The rate constants for the formation of 1,2,3-TCB (k21) and 1,2,4-TCB (k22) were 0.0032+/-0.0001 d-1 and 0.051+/-0.003 d-1 from alpha-HCH, and 0.0017+/-0.0001 d-1 and 0.0041+/-0.0002 d-1 from gamma-HCH at pH 8.28 and 25 degrees C. Both k21 and k22 also showed an increase by about one order of magnitude per pH unit from pH 8.28 to pH 12.02. The Ea values were 64.4+/-6.8 and 88.8+/-5.2 kJ mol-1, respectively, for the formation of 1,2,4-TCB and 1,2,3-TCB from alpha-HCH, and 70.6+/-8.7 and 92.0+/-4.9 kJ mol-1, respectively, for the formation of 1,2,4- and 1,2,3-TCB from gamma-HCH at pH 9.26. Data provided by this study may be used for calculation of the percentages of the TCBs formed at different environmental conditions. 相似文献
904.
905.
906.
907.
Alin C. Dirtu Anna J. Buczyńska Ana F. L. Godoi Rodrigo Favoreto László Bencs Sanja S. Potgieter-Vermaak Ricardo H. M. Godoi René Van Grieken Luc Van Vaeck 《Environmental monitoring and assessment》2014,186(10):6445-6457
The daily and seasonal atmospheric concentrations, deposition fluxes and emission sources of a few C3–C9 gaseous alkyl nitrates (ANs) at the Belgian coast (De Haan) on the Southern North Sea were determined. An adapted sampler design for low- and high-volume air-sampling, optimized sample extraction and clean-up, as well as identification and quantification of ANs in air samples by means of gas chromatography mass spectrometry, are reported. The total concentrations of ANs ranged from 0.03 to 85 pptv and consisted primarily of the nitro-butane and nitro-pentane isomers. Air mass backward trajectories were calculated by the Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model to determine the influence of main air masses on AN levels in the air. The shorter chain ANs have been the most abundant in the Atlantic/Channel/UK air masses, while longer chain ANs prevailed in continental air. The overall mean N fluxes of the ANs were slightly higher for summer than those for winter-spring, although their contributions to the total nitrogen flux were low. High correlations between AN and HNO2 levels were observed during winter/spring. During summer, the shorter chain ANs correlated well with precipitation. Source apportionment by means of principal component analysis indicated that most of the gas phase ANs could be attributed to traffic/combustion, secondary photochemical formation and biomass burning, although marine sources may also have been present and a contributing factor. 相似文献
908.
Horemans B Worobiec A Buczynska A Van Meel K Van Grieken R 《Journal of environmental monitoring : JEM》2008,10(7):867-876
Total suspended particulate (TSP), PM(2.5) and BTEX were collected in nine offices in the province of Antwerp, Belgium. Both indoor and outdoor aerosol samples were analysed for their weight, elemental composition, and water-soluble fraction. Indoor TSP and PM(2.5) concentrations ranged from 7-31 microg m(-3) and 5-28 microg m(-3), with an average of 18 and 11 microg m(-3), respectively. Of all the elements analysed in indoor TSP, more than 95% was represented by Al, Si, K, Ca, Fe, Cl and S, accounting for 12% of the TSP by mass. The other elements showed significant enrichment relative to the earth's crust. The water-soluble ionic fraction accounted for almost 30% of the sampled indoor TSP by weight, and was enriched by anthropogenic activities. It was shown that the indoor PM levels varied among the offices, depending on the ventilation pattern, location, and occupation density of the office. Indoor BTEX levels ranged together from 5-47 microg m(-3) and were considerably higher than the corresponding outdoor levels. It was observed that some recently constructed and renovated buildings were clearly burdened with elevated levels for toluene, ethyl benzene, and xylenes, while outdoor air was found to be the main source for BTEX levels at the 'older' offices. 相似文献
909.
Stranger M Potgieter-Vermaak S Sacco P Quaglio F Pagani D Cocheo C Godoi AF Van Grieken R 《Environmental monitoring and assessment》2009,149(1-4):411-417
A diffusive sampling method for the determination of gaseous acetic and formic acids, using a radial symmetry diffusive sampler, has been optimised for a 7-day exposure time in this study. Sampling rate determinations were performed on data obtained from a dynamic exposure chamber, simulating the indoor conditions of an empty, closed, room, at room temperature and minimal wind speed. Analysis has been performed by means of ion chromatography. The sampling rates for formic acid concentrations of 128 microg m(-3) and 1248 microg m(-3) were determined to be 91.2 +/- 3.9 ml min(-1) and 111.6 +/- 2.8 ml min(-1), respectively. The acetic acid sampling rate was independent of the concentration in the range 160 microg m(-3)-1564 microg m(-3), and amounted to 97.3 +/- 3.1 ml min(-1). Experimentally determined sampling rates showed deviations of 3% for acetic acid, and 3-21% for formic acid, in relation to theoretically derived values. The blank values were as low as 1.69 +/- 0.07 microg for formic acid and 1.21 +/- 0.14 microg for acetic acid, and detection limits lower than 0.5 microg m(-3) could be achieved, which is an improvement of 98-99% compared to previously validated diffusive sampling methods. This study describes the first step of an extended validation program in which the applicability of these types of samplers for the measurement of organic acids will be validated and optimised for the environmental conditions typical for museum showcases. 相似文献
910.
Polycyclic aromatic hydrocarbons in water, sediment and soil of the Songhua River Basin, China 总被引:4,自引:0,他引:4
Wan-Li Ma Li-Yan Liu Hong Qi Zi-Feng Zhang Wei-Wei Song Ji-Min Shen Zhong-Lin Chen Nan-Qi Ren Josey Grabuski Yi-Fan Li 《Environmental monitoring and assessment》2013,185(10):8399-8409
The Songhua River is the third largest river in China and the primary source of drinking and irrigation water for northeastern China. The distribution of 16 priority polycyclic aromatic hydrocarbons (PAHs) in water [dissolved water (DW) and suspended particulate matter (SPM)], sediment, and soil in the river basin was investigated, and the associated risk of cancer from these PAHs was also assessed. The total concentration of PAHs ranged from 13.9 to 161 ng L?1 in DW, 9.21 to 83.1 ng L?1 in SPM, 20.5 to 632 ng g?1 dw (dry weight) in sediment, and from 30.1 to 870 ng g?1 dw in soil. The compositional pattern of PAHs indicated that three-ring PAHs were predominant in DW and SPM samples, while four-ring PAHs dominated in sediment and soil samples. The spatial distribution of PAHs revealed some site-specific sources along the river, with principal component analysis indicating that these were from pyrogenic sources (such as coal and biomass combustion, and vehicle emissions) and coke oven emission distinguished as the main source of PAHs in the Songhua River Basin. Based on the ingestion of PAH-contaminated drinking water from the Songhua River, cancer risk was quantitatively estimated by combining the Incremental Lifetime Cancer Risk assessment model and BaP-equivalent concentration for five age groups of people (adults, teenagers, children, toddlers, and infants). Overall, the results suggest that the estimated integrated lifetime cancer risk for all groups was in acceptable levels. This study is the first attempt to provide information on the cancer risk of PAHs in drinking water from the Songhua River. 相似文献