全文获取类型
收费全文 | 391篇 |
免费 | 59篇 |
国内免费 | 85篇 |
专业分类
安全科学 | 34篇 |
废物处理 | 10篇 |
环保管理 | 38篇 |
综合类 | 155篇 |
基础理论 | 229篇 |
污染及防治 | 34篇 |
评价与监测 | 22篇 |
社会与环境 | 11篇 |
灾害及防治 | 2篇 |
出版年
2024年 | 1篇 |
2023年 | 8篇 |
2022年 | 9篇 |
2021年 | 25篇 |
2020年 | 16篇 |
2019年 | 23篇 |
2018年 | 20篇 |
2017年 | 17篇 |
2016年 | 24篇 |
2015年 | 26篇 |
2014年 | 28篇 |
2013年 | 31篇 |
2012年 | 17篇 |
2011年 | 28篇 |
2010年 | 27篇 |
2009年 | 32篇 |
2008年 | 31篇 |
2007年 | 28篇 |
2006年 | 27篇 |
2005年 | 21篇 |
2004年 | 14篇 |
2003年 | 19篇 |
2002年 | 15篇 |
2001年 | 10篇 |
2000年 | 1篇 |
1999年 | 5篇 |
1998年 | 2篇 |
1997年 | 2篇 |
1996年 | 4篇 |
1995年 | 2篇 |
1994年 | 1篇 |
1993年 | 3篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1989年 | 2篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1983年 | 1篇 |
1982年 | 2篇 |
1980年 | 3篇 |
1979年 | 1篇 |
1977年 | 1篇 |
1974年 | 1篇 |
1971年 | 1篇 |
排序方式: 共有535条查询结果,搜索用时 78 毫秒
311.
Junxia Wang Maud Mercury Maurice Millet Michel Montury 《Environmental pollution (Barking, Essex : 1987)》2009,157(2):365-370
To estimate the atmospheric exposure of the greenhouse workers to pesticides, solid phase microextraction (SPME) was used under non-equilibrium conditions. Using Fick's law of diffusion, the concentrations of pesticides in the greenhouse can be calculated using pre-determined sampling rates (SRs). Thus the sampling rates (SRs) of two modes of SPME in the lab and in the field were determined and compared. The SRs for six pesticides in the lab were 20.4-48.3 mL min−1 for the exposed fiber and 0.166-0.929 mL min−1 for the retracted fiber. In field sampling, two pesticides, dichlorvos and cyprodinil were detected with exposed SPME. SR with exposed SPME for dichlorvos in the field (32.4 mL min-1) was consistent with that in the lab (34.5 mL min-1). SR for dichlorvos in the field (32.4 mL min−1) was consistent with that in the lab (34.5 mL min−1). The trends of temporal concentration and the inhalation exposure were also obtained. 相似文献
312.
实验考察了直接回用未脱水的给水厂污泥(undewatered water treatment sludge,UWTS)做絮凝剂进行畜禽养殖废水预处理的可行性.单因素实验结果表明,随着投加量和pH的增加,出水悬浮物浓度(suspended solid,SS)、化学需氧量(chemical oxygen demand,COD)和总磷(total phosphorus,TP)的去除率不断增加;随着快速搅拌速度的提高,UWTS的絮凝效果呈现先增强后减弱的趋势;随着沉淀时间的延长,出水中SS、COD和TP的去除率起初逐渐增大,但15 min后去除率变化不明显.进一步的正交实验分析结果表明,UWTS回用做絮凝剂的最佳反应条件为投加量2 800 mg/L,快速搅拌速度300 r/min,沉淀时间15 min,此时对应的SS、COD和TP的去除率分别为74.8%、54.6%和60.5%.最佳反应条件下的粒径分析结果表明,UWTS的投加使得粒径范围在40 ~ 180 μm的颗粒物得到了去除.尽管与商品化絮凝剂相比,UWTS的絮凝效果略差,但是,利用其预处理畜禽养殖废水具有成本优势,因而具有应用潜力. 相似文献
313.
Ecological risk assessment of organic waste amendments using the species sensitivity distribution from a soil organisms test battery 总被引:2,自引:0,他引:2
Domene X Ramírez W Mattana S Alcañiz JM Andrés P 《Environmental pollution (Barking, Essex : 1987)》2008,155(2):227-236
Safe amendment rates (the predicted no-effect concentration or PNEC) of seven organic wastes were estimated from the species sensitivity distribution of a battery of soil biota tests and compared with different realistic amendment scenarios (different predicted environmental concentrations or PEC). None of the wastes was expected to exert noxious effects on soil biota if applied according either to the usual maximum amendment rates in Europe or phosphorus demands of crops (below 2 tonnes DM ha−1). However, some of the wastes might be problematic if applied according to nitrogen demands of crops (above 2 tonnes DM ha−1). Ammonium content and organic matter stability of the studied wastes are the most influential determinants of the maximum amendment rates derived in this study, but not pollutant burden. This finding indicates the need to stabilize wastes prior to their reuse in soils in order to avoid short-term impacts on soil communities. 相似文献
314.
Nahid Akhtar Hidetoshi Inada Taisuke Kondo Ryo Funada 《Environmental pollution (Barking, Essex : 1987)》2010,158(9):2970-2976
To assess the effects of tropospheric O3 on rice cultivated in Bangladesh, four Bangladeshi cultivars (BR11, BR14, BR28 and BR29) of rice (Oryza sativa L.) were exposed daily to charcoal-filtered air or O3 at 60 and 100 nl l−1 (10:00-17:00) from 1 July to 28 November 2008. The whole-plant dry mass and grain yield per plant of the four cultivars were significantly reduced by the exposure to O3. The exposure to O3 significantly reduced net photosynthetic rate of the 12th and flag leaves of the four cultivars. The sensitivity to O3 of growth, yield and leaf gas exchange rates was not significantly different among the four cultivars. The present study suggests that the sensitivity to O3 of yield of the four Bangladeshi rice cultivars is greater than that of American rice cultivars and is similar to that of Japanese rice cultivars and that O3 may detrimentally affect rice production in Bangladesh. 相似文献
315.
316.
Alga-lysing bacteria have been paid much attention to in recent years. In this study, the alga-lysing strain P05 which was isolated from an immobilizing biosystem was immobilized by coke and elastic filler, forming two biological reactors. The removal efficiencies of algae, NH3-N and organic matter using the two reactors were studied. The results showed that strain P05 was an ideal algal-lysing bacteria strain because it was easy to be immobilized by coke and elastic filler which are of cheap, low biodegradability and the simple immobilization procedure. After 7 d filming, the biological film could be formed and the reactors were used to treat the eutrophic water. These two reactors were of stability and high effect with low cost and easy operation. The optimal hydraulic retention time (HRT) of each reactor was 4 h. The algae removal rates were 80.38% and 82.1% (in term of Chl-a) of coke reactor and filler reactor, respectively. And that of NH3-N were 52.3% and 52.7%. The removal rates of CODMn were 39.03% and 39.64%. The strain P05 was identified as Bacillus sp. by PCR amplification of the 16S rRNA gene, BLAST analysis, and comparison with sequences in the GenBank nucleotide database. 相似文献
317.
Xiaoxiao Zhang Xiang Ding Dilinuer Talifu Xinming Wang Abulikemu Abulizi Mailikezhati Maihemuti Suwubinuer Rekefu 《环境科学学报(英文版)》2021,33(2):279-286
Atmospheric visibility can directly reflect the air quality. In this study, we measured water-soluble ions (WSIs), organic and element carbon (OC and EC) in PM2.5 from September 2017 to August 2018 in Urumqi, NW China. The results show that SO42?, NO3? and NH4+ were the major WSIs, together accounting for 7.32%–84.12% of PM2.5 mass. Total carbon (TC=OC+EC) accounted for 12.12% of PM2.5 mass on average. And OC/EC > 2 indicated the formation of secondary organic carbon (SOC). The levels of SO42?, NO3? and NH4+ in low visibility days were much higher than those in high visibility days. Relative humidity (RH) played a key role in affecting visibility. The extinction coefficient (bext) that estimated via Koschmieder formula with visibility was the highest in winter (1441.05 ± 739.95 Mm?1), and the lowest in summer (128.58 ± 58.00 Mm?1). The bext that estimated via IMPROVE formula with PM2.5 chemical component was mainly contributed by (NH4)2SO4 and NH4NO3. The bext values calculated by both approaches presented a good correlation with each other (R2 = 0.87). Multiple linear regression (MLR) method was further employed to reconstruct the empirical regression model of visibility as a function of PM2.5 chemical components, NO2 and RH. The results of source apportionment by Positive Matrix Factorization (PMF) model showed that residential coal combustion and vehicle emissions were the major sources of bext. 相似文献
318.
利用MODIS和CALIPSO level2气溶胶产品,通过统计分析多个气溶胶光学参数(光学厚度、消光系数、色比和退偏振比)的时空分布及其变化,得出2007~2016年华东地区(27°N~37°N,113°E~123°E)气溶胶三维分布特征.结果表明,华东地区气溶胶光学厚度(AOD)年平均呈现出北高南低,平原高、山地低的分布特征.AOD季节分布表现为春夏高,秋冬低,夏季最高,冬季最低,且研究区域北部(31°N以北)AOD季节变化比南部地区剧烈.气溶胶消光系数(σ)随高度呈指数衰减,秋冬(春夏)低层σ较大(小)但随高度衰减较快(慢),2km以下北高南低.年平均色比(CR)随高度递增,变化范围为0.6~0.7,随时间有减小趋势.CR季节特征为4km以下春季最大,夏季最小且均一;4km以上冬季最大,夏季最小.年平均退偏振比(PDR)随高度递增,变化范围为0.1~0.25,北部较大.PDR季节特征为5km以下春季最大,夏季最小;5km以上冬季最大,夏季最小.从气溶胶组成来看,华东地区2km以下以污染沙尘为主;2~5km春季以沙尘为主,其它季节以烟尘为主;5km以上冬春以沙尘为主,夏秋以烟尘为主. 相似文献
319.
MU Rui-min FAN Zheng-qiu PEI Hai-yan YUAN Xue-liang Liu Si-xiu WANG Xiang-rong 《环境科学学报(英文版)》2007,19(11):1336-1340
Water blooms have become a worldwide environmental problem.Recently,algicidal bacteria have attracted wide attention as possible agents for inhibiting algal water blooms.In this study,one strain of algicidal bacterium B5 was isolated from activated sludge.On the basis of analysis of its physiological characteristics and 16S rDNA gene sequence,it was identified as Bacillusfusiformis.Its algae- lysing characteristics on Microcystis aeruginosa,Chlorella and Scenedesmus were tested.The results showed that:(1)the algicidal bacterium B5 is a Gram-negative bacterium.The 16S rDNA nucleotide sequence homology of strain B5 with 2 strains of B.fusiformis reached 99.86%,so B5 was identified as B.fusiformis;(2)the algal-lysing effects of the algicidal bacterium B5 on M.aeruginosa, Chlorella and Scenedesmus were pronounced.The initial bacterial and algal cell densities strongly influence the removal rates of chlorophyll-α.The greater the initial bacterial cell density,the faster the degradation of chlorophyll-α.The greater the initial algal cell density,the slower the degradation of chlorophyll-α.When the bacterial cell density was 3.6 x l07 cells/ml,nearly 90% of chlorophyll-αwas removed.When the chlorophyll-αconcentration was less than 550μg/L,about 70% was removed;(3)the strain B5 lysed algae by secreting metabolites and these metabolites could bear heat treatment. 相似文献
320.