An attempt had been made to isolate and identify the low polar volatile constituents from Isodon excisa. The dried plants were heat extracted with ethanol and then extracted with petroleum ether. The constituents were...An attempt had been made to isolate and identify the low polar volatile constituents from Isodon excisa. The dried plants were heat extracted with ethanol and then extracted with petroleum ether. The constituents were isolated and analyzed by GC-MS and then we retrieved them on NIST08 mass spectrometry database to determine their structures. Finally, successful results were achieved, 111 compounds were obtained and identified. 105 of them were reported for the first time in lsodon excisa and 22 of them were first found in natural products. Thus, the main constituents of it were found to be Sitosterol （33.28%）, 3-Amino-4-pyrazolecarbonitrile （9.55%）展开更多
When designing and selecting burning equipment for low volatile coal fired boilers,the primary concerns are about coal ignition and burnout.The characteristics of ignition and burnout are analyzed for low volatile coa...When designing and selecting burning equipment for low volatile coal fired boilers,the primary concerns are about coal ignition and burnout.The characteristics of ignition and burnout are analyzed for low volatile coal and the technical measures are discussed for enhancing the combustion and burnout.The adaptability of tangential firing,wall firing and double-arch firing for low volatile coal is studied.Based on the statistic analysis for the main design parameters of domestic low volatile coal fired boilers with tangential firing,wall firing or double-arch W flame firing,the thermal performance for various boiler furnaces is recommended.The combustion systems for different types of boilers are also put forward for coals with different volatiles.展开更多
文摘An attempt had been made to isolate and identify the low polar volatile constituents from Isodon excisa. The dried plants were heat extracted with ethanol and then extracted with petroleum ether. The constituents were isolated and analyzed by GC-MS and then we retrieved them on NIST08 mass spectrometry database to determine their structures. Finally, successful results were achieved, 111 compounds were obtained and identified. 105 of them were reported for the first time in lsodon excisa and 22 of them were first found in natural products. Thus, the main constituents of it were found to be Sitosterol （33.28%）, 3-Amino-4-pyrazolecarbonitrile （9.55%）
文摘When designing and selecting burning equipment for low volatile coal fired boilers,the primary concerns are about coal ignition and burnout.The characteristics of ignition and burnout are analyzed for low volatile coal and the technical measures are discussed for enhancing the combustion and burnout.The adaptability of tangential firing,wall firing and double-arch firing for low volatile coal is studied.Based on the statistic analysis for the main design parameters of domestic low volatile coal fired boilers with tangential firing,wall firing or double-arch W flame firing,the thermal performance for various boiler furnaces is recommended.The combustion systems for different types of boilers are also put forward for coals with different volatiles.
