首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   164篇
  免费   13篇
  国内免费   10篇
安全科学   9篇
废物处理   2篇
环保管理   14篇
综合类   51篇
基础理论   8篇
污染及防治   20篇
评价与监测   78篇
社会与环境   4篇
灾害及防治   1篇
  2024年   1篇
  2023年   4篇
  2022年   4篇
  2021年   8篇
  2020年   7篇
  2019年   5篇
  2018年   3篇
  2017年   6篇
  2016年   9篇
  2015年   8篇
  2014年   8篇
  2013年   11篇
  2012年   10篇
  2011年   8篇
  2010年   14篇
  2009年   8篇
  2008年   8篇
  2007年   8篇
  2006年   7篇
  2005年   6篇
  2004年   2篇
  2003年   8篇
  2002年   6篇
  2001年   9篇
  2000年   2篇
  1999年   4篇
  1997年   3篇
  1996年   3篇
  1995年   2篇
  1993年   3篇
  1984年   1篇
  1979年   1篇
排序方式: 共有187条查询结果,搜索用时 171 毫秒
91.
对2,4-二硝基苯肼吸附衍生-高效液相色谱(DNPH-HPLC)法和罐采样/气相色谱-质谱(GC-MS)法的测定条件进行优化,将两种方法测定环境空气中13种醛酮类化合物(OVOCs)的结果做比对分析。结果表明,HPLC法和GC-MS法均可实现一次进样13种OVOCs全分析,方法检出限分别为0.26μg/m3~1.39μg/m3和0.49μg/m3~1.10μg/m3,加标回收率分别为95.9%~111%和52.0%~138%。两种方法测定实际样品,检出组分的测定结果无显著性差异;HPLC法适合测定环境空气中低碳类(C1~C3)低浓度OVOCs,GC-MS法适合测定多碳类(C4~C8)低浓度OVOCs。  相似文献   
92.
青岛地区气溶胶的酸碱特性   总被引:1,自引:0,他引:1  
应用实验和酸碱平衡计算的方法,研究青岛地区气溶胶的酸碱特性,测定气溶胶中硫酸的含量,推断气溶胶中的Ca2+,Mg2+的存在形式与SO2-4,NO-3的来源以及IP和TSP对降水酸性的贡献?发现IP气溶胶对降水总的影响是起中和作用,中和能力以碳酸盐计相当于它所含的钙?镁盐的(22±20)%?   相似文献   
93.
甲基橙分光光度法测定环境空气及工业废气中游离溴   总被引:8,自引:0,他引:8  
以0.005‰甲基橙溶液富集吸收,用分光光度法测定环境空气和工业废气中的游离溴,并对样品的采集、保存和最佳测定条件进行了研究。结果表明,方法的采样效率〉97%,线性良好,精密度和准确度均较高,方法灵敏,按20L采样体积计,方法的最低检出浓度为0.025mg/m^3。  相似文献   
94.
泰山顶与济南市大气臭氧浓度变化规律研究   总被引:1,自引:1,他引:0  
利用2003年7月至9月在泰山顶和济南市3个月的臭氧(O3)自动连续监测数据,对两地O3浓度的频率分布、日变化和日际变化等特征进行对照分析。实验结果表明,泰山顶O3小时平均浓度频率分布比较集中,济南市O3小时平均浓度频率分布比较分散。泰山顶各月O3小时平均浓度的平均值和日均值均高于济南市;泰山顶O3小时平均浓度的最大值低于济南市,而O3小时平均浓度的最小值要高于济南市。泰山顶O3小时平均浓度日变化规律与济南市O3小时平均浓度日变化规律有很大差别,泰山顶O3小时平均浓度日变化很平缓,最大值与最小值相差不大,济南市O3小时平均浓度一般在中午和午后浓度较高,早晨和夜晚较低。  相似文献   
95.
Benzene is a carcinogenic air pollutant for which European legislation has set an annual limit and criteria for the number of fixed monitoring sites within air quality networks(AQMN). However, due to the limited number of fixed sites for benzene measurement, exposure data are lacking. Considering the relationship between benzene levels and other variables monitored within an AQMN, such as NO2, O3, temperature, solar radiation, and accumulated precipitation, this study propo...  相似文献   
96.
利用罐采样-低温浓缩-气相色谱-质谱联用仪结合冷柱箱技术,建立了一次进样同时分析环境空气中116种挥发性有机物的方法.利用苏玛罐采集环境空气样品,液氮低温冷凝浓缩进样,经配有冷柱箱的气相色谱-质谱法进行分析.通过优化冷凝参数和程序升温条件,最终用-35℃初始柱温成功保留住低碳组分,实现用一根色谱柱同时分离低碳和高碳组分...  相似文献   
97.
Ambient concentrations of PM2.5 and PM10 are of concern with respect to effects on human health and environment. Increased levels of mortality and morbidity have been associated with respirable particulate air pollution. In India, it is not yet mandatory to monitor PM2.5 levels therefore very limited information is available on PM2.5 levels. To understand the fine particle pollution and also correlate with PM10 which are monitored regularly in compliance with ambient air quality standards. This study was carried out to monitor PM2.5, PM10, and NO2 for about one year in a residential cum commercial area of Mumbai city with a view to understand their correlation. The average PM2.5 concentration at ambient and Kerbsite was 43 and 69 μg/m3. The correlation coefficients between PM2.5 and PM10 at ambient and Kerbsite were 0.83 and 0.85 respectively thus indicating that most of the PM2.5 and PM10 are from similar sources. TSP, PM10 levels exceeded Central Pollution Control Board(CPCB) standard during winter season. PM2.5 levels also exceeded 24 hourly average USEPA standard during winter season indicating unhealthy air quality.  相似文献   
98.
The comparison with National Ambient Air Quality Standards does not always depict a true pic-ture of the Air Quality Status of a study area. As an alternative an index that measures depreciation in Air Quality on more realistic terms has been proposed and applied to the ambient air monitoring data collected from some areas of Korba Coalfields in India. Results have been discussed in detail to illustrate the applica-tion of the proposed index and utility in bringing out more realistic air quality assessment.  相似文献   
99.
沈阳市环境空气质量天气模式预报方法   总被引:2,自引:0,他引:2  
应用2003年和2004年6月~8月天气形势资料和同期环境空气自动监测数据进行统计分析,建立夏季天气模式预报方法,同时应用2005年资料进行验证,预报效果较好,环境空气中首要污染物———可吸入颗粒物(PM10)的级别预报准确率、趋势预报准确率和总站发布预报范围准确率分别达到60%、80%和90%,该预报方法可作为业务预报使用。  相似文献   
100.
Khwaja HA  Narang A 《Chemosphere》2008,71(11):2030-2043
Measurements of carbonyls and C2–C6 non-methane hydrocarbons (NMHCs) were made in ambient air at a rural site at the summit of Whiteface Mountain (WFM) in New York State. Alkanes dominated in the samples, with ethane and propane making up about 55% of the total on a carbon-atom basis. Ethane, the longest-lived of the NMHCs, showed a mixing ratio in the range of 0.86–2.1 ppbv. Photochemical ageing analysis indicated an anthropogenic influence on the NMHC levels. The photochemical reactivity of the hydrocarbons, calculated in terms of propylene-equivalent concentration, was dominated by alkenes (propene and ethene), which accounted for 74% of the total NMHC sum. Air mass back-trajectories have been used to investigate the origin of the observed NMHCs and carbonyls. Higher concentrations were found when air masses arrived from the midwestern US corridor. Acetone was the most abundant species, comprising from 31% to 53% of the total detected carbonyls, followed by MEK (15–53%), HCHO (7–39%), and CH3CHO (7–19%). Average concentrations were determined to be 1.61 ppbv for CH3C(O)CH3, 1.40 ppbv for MEK, 1.16 ppbv for HCHO, and 0.49 ppbv for CH3CHO. The variations in carbonyl concentrations were observed to follow patterns similar to variations in O3 concentrations, typical of secondary products. Correlations and statistical analysis of the carbonyls and NMHCs were performed, and showed that most of the compounds derived from mixing and photochemical transformation of long-range transported pollutants from the major source areas. Ranking of the carbonyls with respect to removal of the OH radical showed HCHO to be the most important species, followed by CH3CHO, MEK, and CH3C(O)CH3.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号