全文获取类型
收费全文 | 627篇 |
免费 | 128篇 |
国内免费 | 212篇 |
专业分类
安全科学 | 29篇 |
废物处理 | 18篇 |
环保管理 | 45篇 |
综合类 | 520篇 |
基础理论 | 70篇 |
污染及防治 | 80篇 |
评价与监测 | 186篇 |
社会与环境 | 17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 | 21篇 |
2019年 | 19篇 |
2018年 | 36篇 |
2017年 | 38篇 |
2016年 | 48篇 |
2015年 | 53篇 |
2014年 | 63篇 |
2013年 | 56篇 |
2012年 | 63篇 |
2011年 | 63篇 |
2010年 | 47篇 |
2009年 | 71篇 |
2008年 | 71篇 |
2007年 | 54篇 |
2006年 | 62篇 |
2005年 | 31篇 |
2004年 | 24篇 |
2003年 | 29篇 |
2002年 | 23篇 |
2001年 | 10篇 |
2000年 | 7篇 |
1999年 | 10篇 |
1998年 | 3篇 |
1997年 | 1篇 |
1996年 | 3篇 |
1995年 | 2篇 |
1994年 | 3篇 |
1993年 | 1篇 |
1985年 | 4篇 |
1984年 | 2篇 |
1983年 | 4篇 |
1982年 | 2篇 |
1981年 | 1篇 |
排序方式: 共有967条查询结果,搜索用时 790 毫秒
11.
Roadside PM10 has been monitored by Partisol® at three sitesin Sunderland between August 1997 and February 1998. The sites chosen were an inner city kerbside site; a roadside site adjacentto a dual carriageway on the outskirts of Sunderland with an openaspect; and a rural site.The results indicate that there is a seasonal variation in the relationship between the sites in terms of monitored PM10.In the winter there is a poor correlation between the sites whereas in the summer significant correlations are obtained. Of the sites monitored PM10 is consistently highest at the inner city roadside site. During the summer, exceedances of theU.K. 50 g m-3 standard (DETR, 2000) are associated with conditions suitable for the build-up of photochemical pollutionhowever during the winter period exceedances are recorded duringa variety of weather conditions.At the dual carriageway site PM2.5 has also been recorded and contributions to measured PM10 are 77% in summer and68% in winter. The results illustrate a number of inconsistencies between this study utilising the Partisol® andothers reporting results where PM10 has been monitored by TEOM®. 相似文献
12.
Review on the annual PM10 concentrations over a 10-year period shows that Macau is subjected to severe fine particulate pollution. Investigations of its variation in monthly and daily time scales with the local meteorological records reveal further details. It is found that a distinct feature of the Asian monsoon climates, the changes of wind direction, mainly controls the general trend of PM10 concentration in a year. The monsoon driven winter north-easterly winds bring upon Macau dry and particle enriched air masses leading to a higher concentration in that period while the summer south-westerly winds transport humid and cleaner air to the region leading to a lower PM10 value. This distinct seasonal feature is further enhanced by the lower rainfall volume and frequency as well as mixing height in winter and their higher counterparts in summer. It is also found that the development of tropical cyclones near Macau could also impose episode like PM10 concentration spikes due to the pre-typhoon induced stagnant air motion followed by the swing of wind direction to the northerly. 相似文献
13.
14.
乌鲁木齐市可吸入颗粒物(PM10)与总悬浮颗粒物(TSP)的相关性规律浅析 总被引:1,自引:3,他引:1
通过对乌鲁木齐市的PM10和TSP数据的对比分析,找出PM10在TSP中所占比率(分担率)在采暖季和非采暖季的变化范围,从而使过去采集的TSP数据与PM10数据有一定的可比性,保证监测数据的连续可比。 相似文献
15.
因子分析法解析北京市大气颗粒物PM10的来源 总被引:17,自引:3,他引:17
2004年10月份在北京市6个采样点采集了大气PM10样品,分析了大气颗粒物的质量浓度、元素组成、离子、有机碳(OC)和元素碳(EC)的浓度,并用因子分析模型对颗粒物的来源进行了研究。结果显示,北京市大气颗粒物的来源主要有6类:建筑水泥尘/机动车尾气尘/燃煤尘、土壤风沙尘、二次粒子尘、工业粉尘、生物质燃烧尘和燃油尘。用模型计算得到的各源对PM10的贡献率分别为建筑水泥尘/机动车尾气尘/燃煤尘占36.57%、土壤风沙尘占16.07%、二次粒子尘占12.33%、工业粉尘占10.29%、生物质燃烧尘占6.07%、燃油尘占3.84%、其它占14.84%。其中建筑水泥/机动车尾气尘/燃煤尘、土壤风沙尘、二次粒子尘、工业粉尘是大气颗粒物PM10的主要来源。实验表明,在缺少源成分谱时可以用因子分析模型来分析大气颗粒物的来源及其相对贡献。 相似文献
16.
A positive correlation has been established between increased levels of airborne particulate pollution and adverse health effects, the toxicological mechanisms of which are poorly understood. For toxicologists to unambiguously determine thesemechanisms, truly representative samples of ambient PM10 are required. This presents problems, as PM10 collecting equipment commonly employed, such as the Tapered Element Oscillating Microbalance (TEOM®), heat the inflow toexclude moisture or use fibrous filters, resulting in a PM10sample that may have undergone significant chemical change on thefilter surface or is contaminated by filter fibres. Other systems(i.e. Negretti and Partisol) can successfully collect PM10 without chemical alteration or filter contamination. Comparativecollections from Port Talbot, S. Wales suggest that TEOMs and Negretti/Partisol systems collect different PM10's; the principle difference arising from the TEOM's heating chamber, which precipitates water-soluble ions and volatilises some organic components. This results in both the mass and compositionof the PM10's being altered. Particle size distributionsfor Negretti and Partisol collections highlighted differences mainly attributed to different flow rates. The results of thiswork demonstrate that simple correlations between PM10 massand adverse health effects are problematic. Furthermore, elucidation of the complex fractionation and chemical changes indifferent collectors is necessary. 相似文献
17.
18.
Ports can generate large quantity of pollutants in the atmosphere due to various activities like loading and unloading,transportation, and construction operations. Determination of the character and quantity of emissions from individual sources is an essential step in any project to control and minimize the emissions.In this study a detailed emission inventory of total suspendedparticulate matter (TSP), particulate matter less than 10 m(PM10), sulfur dioxide (SO2) and nitrogen oxides (NOx) for a port and harbour project near Mumbai is compiled. Results show that the total annual average contributions of TSP and PM10 from all the port activitieswere 872 and 221 t yr-1, respectively. Annual average emissions of gaseous pollutants SO2 and NOxwere 56 and 397 t yr-1, respectively, calculatedby using emission factors for different port activities. The maximum TSP emission (419 t yr -1) was from paved roads, while the least (0.4 t yr-1) was from bulk handling activity. The maximum PM10 emission (123 t yr-1) was from unpaved roads and minimum (0.2 t yr-1) from bulk handling operations. Similarly the ratio of TSP and PM10 emission was highest (5.18) from paved roads and least (2.17) from bulk handling operations. Regression relation was derivedfrom existing emission data of TSP and PM10 from variousport activities. Good correlation was observed between TSP andPM10 having regression coefficient >0.8. 相似文献
19.
对悬浮颗粒物室外人体暴露的测定一直受到可用资源的限制。设计有效的网络就要求对测定方法的选择、采样点的数量、采样时间、采样频率等进行调整。采样位置要求能表征因周围污染源对附近地区和城市最小影响的空间数值。虽然大多数判定PM是否达标的测定方法是每第3天至第6天的24h监测,但是室外人体暴露的评价要求连续监测一整天。最好有1h或更短时间的监测时段。更详细的粒径大小和化学性质数据也很有必要,因为较小的颗粒及其特殊的化学物质要比总的样品质量更有助于反映对健康的不良影响。 相似文献
20.
对悬浮颗粒物室外人体暴露的测定一直受到可用资源的限制,设计有效的网络就要求对测定方法的选择、采样点的数量、采样时间、采样频率等进行调整。采样位置要求能表征因周围污染源对附近地区和城市最小影响的空间数值。虽然大多数判定PM是否达标的测定方法是每第3天至第6天的24h监测,但是室外人体暴露的评价要求连续监测一整天,最好有1h或更短时间的监测时段。更详细的粒径大小和化学性质数据也很有必要,因为较小的颗粒及其特殊的化学物质要比总的样品质量更有助于反映对缝康的不良影响。 相似文献