全文获取类型
收费全文 | 594篇 |
免费 | 98篇 |
国内免费 | 206篇 |
专业分类
安全科学 | 24篇 |
废物处理 | 14篇 |
环保管理 | 31篇 |
综合类 | 505篇 |
基础理论 | 66篇 |
污染及防治 | 72篇 |
评价与监测 | 168篇 |
社会与环境 | 16篇 |
灾害及防治 | 2篇 |
出版年
2024年 | 1篇 |
2023年 | 6篇 |
2022年 | 16篇 |
2021年 | 19篇 |
2020年 | 20篇 |
2019年 | 18篇 |
2018年 | 36篇 |
2017年 | 37篇 |
2016年 | 45篇 |
2015年 | 51篇 |
2014年 | 60篇 |
2013年 | 55篇 |
2012年 | 63篇 |
2011年 | 58篇 |
2010年 | 46篇 |
2009年 | 66篇 |
2008年 | 57篇 |
2007年 | 50篇 |
2006年 | 61篇 |
2005年 | 29篇 |
2004年 | 22篇 |
2003年 | 28篇 |
2002年 | 21篇 |
2001年 | 9篇 |
2000年 | 4篇 |
1999年 | 9篇 |
1998年 | 1篇 |
1997年 | 1篇 |
1996年 | 2篇 |
1995年 | 2篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1985年 | 1篇 |
1983年 | 1篇 |
1981年 | 1篇 |
排序方式: 共有898条查询结果,搜索用时 15 毫秒
181.
东营春季PM10中有机碳和元素碳的污染特征及来源 总被引:2,自引:1,他引:1
2010年4月采集了东营市大气PM10样品,测定了PM10的浓度,并采用IMPROVE-TOR方法准确测量了样品中的8个碳组分.结果表明,采样期间,东营市大气PM10的平均浓度为(147.02±56.22) μg/m3;PM10中有机碳(0C)、元素碳(EC)浓度平均值分别为11.82、3.68 μg/m 3;PM10中OC和EC显著相关,表明OC、EC的来源相同;所有采样点PM10中OC/EC均大于2.15,表明存在二次有机碳(SOC)的贡献;PM10中SOC平均质量浓度是3.91 μg/m3,占OC质量浓度的33.08%;通过计算PM10中8个碳组分丰度,初步判断东营市颗粒物中碳的主要来源是汽车尾气、道路扬尘和燃煤. 相似文献
182.
David Galán-Madruga 《环境科学学报(英文版)》2021,33(4):138-147
This work aims to provide a methodology framework which allows to improve the performance and efficiency of an air quality monitoring network (AQMN). It requires to be constituted by a minimum and reliable number of measurement sites. Nevertheless, the AQMN efficiency should be assessed over time, as a consequence of the possible emergence of new emission sources of air pollutants, which could lead to variations on their spatial distribution within the target area. PM10 particles data monitored by the Community of Madrid's (Spain) AQMN between 2008 and 2017 were used to develop a methodology to optimize the AQMN performance. The annual spatial distribution of average PM10 levels over the studied period monitored by all current stations vs those more representative was provided by a geographic information system (GIS), and the percentage of similarity between both postulates was quantified using simple linear regression (> 95%). As one innovative tool of this study, the practical application of the proposed methodology was validated using PM10 particles data measured by AQMN during 2007 and 2018, reaching a similitude degree higher than 95%. The influence of temporal variation on the proposed methodological framework was around 20%.The proposed methodology sets criteria for identifying non-redundant stations within AQMN, it is also able to appropriately assess the representativeness of fixed monitoring sites within an AQMN and it complements the guidelines set by European legislation on air pollutants monitoring at fixed stations, which could help to tackle efforts to improve the air quality management. 相似文献
183.
184.
可持续发展战略与上海“十五”计划编制的研究 总被引:1,自引:0,他引:1
“十五”计划是上海市进入21世纪的第1个5年计划,从提升自身发展质量和国际综合竞争能力的要求分析了将可持续发展战略纳入上海“十五”计划编制工作的必要性和重要性,围绕思想创新、目标创新、框架创新、指标创新等4个方面探讨了以可持续发展为定位的上海“十五”计划编制思路。 相似文献
185.
使用X射线衍射技术(XRD)和扫描电镜技术(SEM/EDX)对北京PM10中的矿物组分进行了分析.结果表明,北京PM10中的矿物组分存在明显的季节变化规律,春季PM10中的矿物组成种类最多;秋季PM10中的矿物种类最少;在夏季PM10中,矿物的种类有所减少,却有新的物种出现,如NH4Cl、K(NH4)Ca(SO4)2?H2O、As2O3?SO3等.粘土矿物是北京PM10中含量最高的矿物,石英的含量次之,其他依次为方解石、石膏、长石、白云石以及其他矿物颗粒;北京PM10中还存在一定数量的复合颗粒,颗粒表面常有S、Cl元素的存在. 相似文献
186.
电感耦合等离子体-质谱法研究大气颗粒物中元素浓度 总被引:1,自引:0,他引:1
1 IntroductionAirborneparticulatematterisoneoftheimportantmarkersofairqualityandisanimportanthealthconcerninurbanareas,especiallywithrespecttoanumberofchronicrespiratorydiseases.Medicaldatasuggeststhatitisthisfractionofparticulatematterthatbecomesdeeplyi… 相似文献
187.
Shigong Wang Wei Yuan Kezheng Shang 《Atmospheric environment (Oxford, England : 1994)》2006,40(40):7975-7982
In this study the frequencies of PM10 (as key urban pollutant) in 14 key environmental protection cities in northern China were analyzed. It follows that the PM10 concentration in the high-frequency period is higher with an extent 0.009–0.066 mg m−3 than in the low-frequency period of 2001–2002. Further the impacts of three kinds of dust events on the PM10 concentration in four cities (Beijing, Hohhot, Xi’an and Lanzhou) were explored. The results showed that different kinds of dust events have different influences on variation of PM10 concentration in these four cities. In Lanzhou and Hohhot, which are near the source areas of dust events, the contribution degree of these three dust events to the PM10 is: floating dust>dust storm>blowing dust. Whereas, in Beijing and Xi’an situated in dust event passing areas, the mean value of PM10 concentration is higher in blowing dust than in floating dust (no dust storm). In addition, the influences of dust events on PM10 concentration are different in the cities on different dust event paths. In Beijing and Hohhot (on the northern path), the high PM10 concentration is usually caused by blowing dust. But in both Lanzhou and Xi’an (on the western/northwestern path) the high PM10 pollution concentration is usually caused by floating dust. 相似文献
188.
Sergio Rodríguez Xavier Querol Andrés Alastuey Jesús de la Rosa 《Environmental Chemistry Letters》2007,5(1):1-7
This article synthesises the results obtained in several projects on atmospheric aerosol (particulate matter – PM) pollution
developed during the last years in the Western Mediterranean. It focuses on particulate matter sources and the strategies
for suitable monitoring in ambient air. The article has been structured in several sections that give response to the main
questions that prompted these studies. After analysing the main PM features in the Mediterranean, a brief review of the main
factors differentiating the particulate matter composition with respect to Central Europe is presented. Finally, the suitability
of the different metrics or parameters for monitoring ambient air PM levels in different types of environments is discussed.
Selected article from the 6th European Meeting on Environmental Chemistry, University of Belgrade, Serbia and Montenegro organized
by Prof. Dr. Branimir Jovancicevic (www.research.plymouth.ac.uk/ace). 相似文献
189.
A twin pregnancy with trisomy 10 p due to a paternal 10;12 translocation is reported. The prenatal diagnosis steps followed in twin pregnancies are reviewed and the concordant features of trisomy 10 p seen in both fetuses confirm previous reports on the clinical features of this chromosomal defect. 相似文献
190.