全文获取类型
收费全文 | 220篇 |
免费 | 35篇 |
国内免费 | 212篇 |
专业分类
安全科学 | 20篇 |
废物处理 | 13篇 |
环保管理 | 12篇 |
综合类 | 320篇 |
基础理论 | 40篇 |
污染及防治 | 51篇 |
评价与监测 | 9篇 |
社会与环境 | 1篇 |
灾害及防治 | 1篇 |
出版年
2023年 | 7篇 |
2022年 | 19篇 |
2021年 | 18篇 |
2020年 | 16篇 |
2019年 | 10篇 |
2018年 | 13篇 |
2017年 | 14篇 |
2016年 | 20篇 |
2015年 | 13篇 |
2014年 | 14篇 |
2013年 | 29篇 |
2012年 | 24篇 |
2011年 | 20篇 |
2010年 | 24篇 |
2009年 | 21篇 |
2008年 | 13篇 |
2007年 | 29篇 |
2006年 | 26篇 |
2005年 | 19篇 |
2004年 | 16篇 |
2003年 | 16篇 |
2002年 | 18篇 |
2001年 | 10篇 |
2000年 | 12篇 |
1999年 | 5篇 |
1998年 | 11篇 |
1997年 | 8篇 |
1996年 | 7篇 |
1995年 | 3篇 |
1994年 | 2篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1991年 | 4篇 |
1989年 | 2篇 |
1988年 | 2篇 |
排序方式: 共有467条查询结果,搜索用时 974 毫秒
411.
412.
C. Borrego O. Tchepel A. Monteiro N. Barros A. Miranda 《Water, Air, & Soil Pollution: Focus》2002,2(5-6):487-499
The main objective of this work is to analyse how uncertainties in emission data of nitrogen oxides (NOx) and volatile organic compounds (VOC), originated from road traffic, influence the model prediction of ozone (O3) concentration fields. Different methods to estimate emissions were applied and results were compared in order to obtain their variability. Based on these data, different emission scenarios were compiled for each pollutant considering the minimum and the maximum values of the estimated emission range. These scenarios were used as input to the MAR-IV mesoscale modelling system. Simulations have been performed for a summer day in the Northern Region of Portugal. The different approaches to estimate NOx and VOC traffic emissions show a significant variability of absolute values and of their spatial distribution. Comparison of modelling results obtained from the two scenarios presents a dissimilarity of 37% for ozone concentration fields as a response of the system to a variation in the input emission data of 63% for NOx and 59% for VOC. Far beyond all difficulties and approximations, the developed methodology to build up an emission data base shows to be consistent and an useful tool in order to turn applicable an air quality model. Nevertheless, the sensitivity of the model to input data should be considered when it is used as a decision support tool. 相似文献
413.
The catalytic effect of alumina on the destruction of toluene, benzene, acetone and methanol, in DC pulsed corona discharge reactor was studied. In the presence of alumina the inlet concentration of the VOCs was varied from ~5×10-6mol/L to ~80×10-6mol/L, and their decomposition efficiency (conversion %) was found to be 99%—80% for toluene, 99%—97% for benzene, 95%—92% for acetone, and 72%—85% for methanol. Corresponding decomposition in the absence of alumina was 90%—38% for toluene, 89%—57% for benzene, 42%—30% for acetone, and 47%—19% for methanol. Feed gas flow rate was 400 cm3/min and power reading from DC source was 7.4 W in all of the experiments. Alumina also shifted the CO/CO2 ratio in the by products in favor of CO2. Ozone concentration at the reactor outlet was higher in the presence of alumina. Enhancement in VOCs decomposition by alumina was explained on the basis of higher concentration of ozone and its precursor atomic oxygen [O] . Decomposition efficiency (conversion %) for individual compounds was found to be inversely proportional to the ionization potential of the compound, under identical conditions. Double DC high voltage sources pulse generator was tested and found to improve VOCs decomposition compared with the conventional single DC high voltage source. 相似文献
414.
Zhang Yuan-hang Xie Shao-dong Zeng Li-min Wang Hui-xiang Yu Kai-heng Zhu Chang-jian Pan Nan-ming Wang Bo-guang 《环境科学学报(英文版)》1999,11(3)
A comprehensive field measurement was set up in Guangzhou City of China and the key was placed on NOx and O3 pollution. The results indicated that the average driving speed of vehicle was only 14 km/h in downtown with high frequency of idle and acceleration. Upward fluxes of CO and NO were observed in Dongfeng street. NOx annual mean concentration in urban area increased year by year, and NOx was identified as the most important pollutant since 1995. Photochemical smog pollution was serious in general,spatial and seasonal distribution of O3 was observed. O3 concentration was kept in a high level in autumn, and its formation was restrained in summer due to frequent thunderstorm and high humidity. The numerical simulation showed the average concentration 相似文献
415.
Photochemical pollution in Lanzhou, China - A case study 总被引:7,自引:0,他引:7
Tang Xiaoyan Li Jinglong Dong ZhenXing Wang Yuying Wang Wenxing Qi Liwen Liu Xiling Zhang Yutian Zhang Xuejin Tian Bingshen Jin Suwen Yang Lingqing Zhang Yixin 《环境科学学报(英文版)》1989,1(1):31-38
The photochemical air pollution in Xigu district of Lanshou city, Gansu Province was studied during a period of 1981-1984. The extremely high NMHC/NOx ratio and ozone level elevation after rain have been noticed. A series of outdoor and indoor reaction chamber simulation experiments conducted in order to understand the specific conditions. The ozone formation under NMHC/NOx condition and the possible reason for high ozone concentration after rain are discussed. 相似文献
416.
417.
研究了利用光催化-臭氧协同处理微污染水体.分别考察了单一作用和协同作用、不同降解时间、pH值以及不同负载方式下的去除率。 相似文献
418.
异相催化是催化反应的重要组成部分,其应用十分广泛。固一液异相催化作为环境科学领域中的一项比较新颖的技术,在研究污染物在多介质环境中的迁移转化行为、开发受污染环境修复及污废水处理新技术等诸多方面都具有很大的发展潜力。因此,对不同类型固一液异相催化剂在环境科学领域的应用研究逐渐成为国内外环境科学领域的研究热点之一。其中,金属和金属氧化物因对某些氧化一还原反应具有较好的催化作用,在饮用水脱氮、污废水脱卤及深度氧化处理等水处理领域的应用较为广泛;固态酸催化剂能催化聚合、裂化、水解反应,因此与某些有机污染物的降解密切相关;将同相催化剂固定化为异相催化剂,同样成为新技术开发的方向之一;天然催化剂对污染物在多介质环境中行为影响的研究近年来也屡有发表。此外,载体因对催化剂的活性及应用具有重要影响,也日益受到关注。文章对环境科学领域中固一液异相催化剂的应用研究进行了综述。 相似文献
419.
420.
Traffic emission and its impact on air quality in Guangzhou area 总被引:1,自引:0,他引:1
Zhang Yuan |hang Xie Shao |dong Zeng Li |min Wang Hui |xiang Laboratory of Atmospheric Environmental Simulation ESPC Center of Environmental Sciences Peking University Beijing China Yu Kai |heng Zhu Chang |jian Pan Nan |ming Wang 《环境科学学报(英文版)》1999,(3)
1 IntroductionIntheprocessofrapidurbanization,totalamountofvehicleinChinaincreaseddramaticallyandreachedmorethan20millionin1995withanaverageincreaserateof15%.Becauseofpoorqualityofvehicle,badroadcondition,lowdrivingspeed,andnocatalyticconverter,theem… 相似文献