Solid-phase microextraction (SPME) is a rapid sample preparation in volatile analysis. The aromatic volatile compositions of ‘Kuerle’ were analyzed using SPME and gas chromatography-mass spectrometry (GC-MS). The effect of different types of fibers, extraction time, and extraction temperature on the volatile results were compared and discussed. The results were as followed. Results showed that 65μm PDMS/DVB fiber had the best effect of extraction. The optimum factors such as extraction time and temperature were 45 min and 40°C.
The standard molar enthalpies of combustion, (298.15K), of high-carbon faaty alochols (tetradecanol, hexadecanol, stearyl alcohol) were obtained by a precise thermal isolation oxygen bomb calorimeter. The values obtained are, respectively, –(9126.39) kJ•mol-1, –(10446.15) kJ•mol-1, and –(11780.49) kJ•mol-1 for tetradecanol, hexadecanol, and stearyl alcohol. It was found that their standand molar enthlpies of combustion increase when the carbon number increases in the substances. There were also good agreement between the experimental and literature results for tetradecanol and tetradecanol. And the standard molar enthalpies of combustion of stearyl alcohol provided necessary thermodynamics basic data. Therefore, these data are available for the exploiting new synthesis method, engineering design and industry production on high-carbon alochols.
While measuring the steam humidity using microwave cylindrical cavity, thanks to the thermal expansion effect of metal, the resonant frequency changes as temperature changes. Such phenomenon reduces the measurement accuracy. This paper analyses the phenomenon, and discusses an amended calculation method which will increase the test accuracy. Compared with lab test results, this amended method becomes more convictive.
In order to promote combination on work and study, according to teaching requirements on "coke production technology", the teachers with teaching team at coal and chemical led the students with first class on teaching reforming on coal and chemical to carry on designing and making with coke oven model. Model making was a proven design method and integrated design process with profound meaning [. Model making practices was devoted into the teaching process, greatly stimulated the students enthusiasm, cultivated the career ability, social skills and methodical competence on students.Teaching effect is obvious [ .
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