The research adopts open sampling method and TCT-GC/MS(Thermodesorption Cold Trap-Gas Chromatography/Mass Spectrometery) apparatus to collect and analyze the volatile organic compounds(VOCs) of Platycladus orientalis ...
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The research adopts open sampling method and TCT-GC/MS(Thermodesorption Cold Trap-Gas Chromatography/Mass Spectrometery) apparatus to collect and analyze the volatile organic compounds(VOCs) of Platycladus orientalis forest,with the intention of researching the compounds and diurnal variation of VOCs of *** forest in natural state in Beijing Western Hills in *** results are as follows:(1) There are 160 kinds(11 categories) of volatile organic compounds,containing Alkyl Hydrocarbon,Ketone,Alcohol,Acid,Aldehyde,Alkene,Ester,Aromatic hydrocarbon,Ether,Hydroxybenzene and *** content of Alkyl Hydrocarbon,Ketone,Acid and Aldehyde occupy a greater percentage among all compounds.(2) The diurnal variation curve of total volatile organic compounds(TVOC) is characterized as "one peak at 11:00(36.44%) and one vale at 3:00(12.76%)".Generally,the concentration at daytime is higher than that of night,and higher in morning than in afternoon,with the maximum at noon.(3) The change of Alkyl Hydrocarbon concentration is greater in the morning and about midday,less in the afternoon and *** diurnal variation curve of Ketone concentration appears as "three peaks and three vales".1:00,5:00—7:00 and 11:00 are peak time,3:00,9:00 and 17:00 are vale *** to Acid,its concentration appears two obvious phases: the higher phase is from 9:00 to 17:00,with the maximum at 11:00,and the lower phase is from 19:00 to 7:00,with the minimum at 5:*** Aldehyde concentration,17:00 and 19:00 are the higher phases and also has obvious difference with other time,while the lower phrase has no obvious difference with each other.(4) Alkene is the most important compound to human *** concentration appears as "one peak" at 15:00,which has obvious difference with other ***,its content at daytime is higher than that at night,and higher in afternoon than in morning.
The concentration of air PM10 in six types of green lands in campus of Tsinghua university was measured. The results showed that PM10 concentration exhibited obvious daily and monthly variation,and also had remarkable...
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The concentration of air PM10 in six types of green lands in campus of Tsinghua university was measured. The results showed that PM10 concentration exhibited obvious daily and monthly variation,and also had remarkable difference among different seasons. However there was no remarkable difference in concentration of PM10 within the same season over all types of green lands. As for average concentration,the value was lower in arbor land of spring,autumn and winter,and in lawn of summer. The concentration of PM10 was 43% higher in cloudy days than that of sunny ones. Moreover,the difference increased to 137% between cloudy day after raining and sunny day after raining because of the clarification of rain.
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