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.
Diurnal changes of photosynthesis of Pinus yunnanensis and its influencing factors were studied in dry *** results indicated that in the dry season,the diurnal course of photosynthesis of *** occurred regularly with t...
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Diurnal changes of photosynthesis of Pinus yunnanensis and its influencing factors were studied in dry *** results indicated that in the dry season,the diurnal course of photosynthesis of *** occurred regularly with the environmental factors *** curve of net photosynthetic rate(Pn) and transpiration rate(Tr) had a diurnal change with one-peak curve,the peak of Pn occurred at 14:00 and the peak of Tr appeared at 15:*** was no "midday depression of photosynthesis".The different meteorological factors influencing the photosynthesis were *** photosynthetic active radiation(PAR) was the ecological factor directly effecting on the Pn and stomatal conductance(Cond) of ***,the main factors affecting Tr were temperature leaf(Tl) and *** course of air humidity on the dry season were lower,and its effects on photosynthesis was not significant,which showes that the *** has a strong physiological adaptability on dry season.
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