通过对南方7种典型乔木叶片在空气气氛条件下,升温速度为10℃·min^(-1)的热重分析,研究了其热解特性和热解动力学特征,并基于热解参数对其燃烧性进行了四维评价。结果表明:(1)综纤维素开始分解的温度为140.54~158.67℃,结束温度为3...通过对南方7种典型乔木叶片在空气气氛条件下,升温速度为10℃·min^(-1)的热重分析,研究了其热解特性和热解动力学特征,并基于热解参数对其燃烧性进行了四维评价。结果表明:(1)综纤维素开始分解的温度为140.54~158.67℃,结束温度为372.01~389.91℃。木素开始分解温度为372.01~389.91℃,结束温度为538.63~581.32℃。(2)综纤维素热解的活化能为34.059~48.531 k J·mol^(-1),指前因子为72.012~1 966.463 min^(-1)。木素热解的活化能为31.264~54.091 k J·mol^(-1),指前因子为31.755~1 909.015 min^(-1)。除麻栗和毛竹外,木素热解的活化能和指前因子都高于综纤维素的活化能和指前因子。(3)7种可燃物的四维燃烧性不完全一致。华山松四维燃烧性都高,麻栗都差。其他5个树种的四维燃烧性不一致。展开更多
Fire numbers, burned areas and return intervals in each large scale forest type with average patch area of 500?km 2 in Heilongjiang Province during the period of 1980 to 1999 were obtained by overlapping the ignition ...Fire numbers, burned areas and return intervals in each large scale forest type with average patch area of 500?km 2 in Heilongjiang Province during the period of 1980 to 1999 were obtained by overlapping the ignition points and areas of 1482 forest fires with the Province’s forest type maps in the same period by means of GIS software ARC/INFO. Analysis on the data indicated that the effects of the forest types on fire occurrence and burned areas in the Province were not significant, thus it was not necessary to take forest types into consideration when forest fire hazard was rated on a large scale. Years long human fire suppression activities increased fire return intervals in the region. Comparison was also made on the effects of forest types on fires at various scales.展开更多
文摘通过对南方7种典型乔木叶片在空气气氛条件下,升温速度为10℃·min^(-1)的热重分析,研究了其热解特性和热解动力学特征,并基于热解参数对其燃烧性进行了四维评价。结果表明:(1)综纤维素开始分解的温度为140.54~158.67℃,结束温度为372.01~389.91℃。木素开始分解温度为372.01~389.91℃,结束温度为538.63~581.32℃。(2)综纤维素热解的活化能为34.059~48.531 k J·mol^(-1),指前因子为72.012~1 966.463 min^(-1)。木素热解的活化能为31.264~54.091 k J·mol^(-1),指前因子为31.755~1 909.015 min^(-1)。除麻栗和毛竹外,木素热解的活化能和指前因子都高于综纤维素的活化能和指前因子。(3)7种可燃物的四维燃烧性不完全一致。华山松四维燃烧性都高,麻栗都差。其他5个树种的四维燃烧性不一致。
文摘Fire numbers, burned areas and return intervals in each large scale forest type with average patch area of 500?km 2 in Heilongjiang Province during the period of 1980 to 1999 were obtained by overlapping the ignition points and areas of 1482 forest fires with the Province’s forest type maps in the same period by means of GIS software ARC/INFO. Analysis on the data indicated that the effects of the forest types on fire occurrence and burned areas in the Province were not significant, thus it was not necessary to take forest types into consideration when forest fire hazard was rated on a large scale. Years long human fire suppression activities increased fire return intervals in the region. Comparison was also made on the effects of forest types on fires at various scales.
