由于不同燃烧指标存在明显的差异,致使人们对于火燃烧方式的理解尚不确定。本研究选取黄河上游青海上喇家典型剖面(深度464 cm,年代范围14.5~0 ka B.P.)为对象,结合炭屑和黑碳以及古生态指标,揭示该区域全新世以来的野火历史演变过程。...由于不同燃烧指标存在明显的差异,致使人们对于火燃烧方式的理解尚不确定。本研究选取黄河上游青海上喇家典型剖面(深度464 cm,年代范围14.5~0 ka B.P.)为对象,结合炭屑和黑碳以及古生态指标,揭示该区域全新世以来的野火历史演变过程。研究结果表明末次冰期和全新世早期,气候较为干旱,以明烧为特征的草原区域野火时常发生,与东亚季风气候所控制燃料特征和湿度密切相关。全新世中期,气候较现在温暖而湿润,生物成壤作用强烈,该地区整体上自然野火发生处于较低水平。其中,4200~3850 a B.P.和3400~3000 a B.P.这两个阶段的粗颗粒炭屑通量峰值分别是齐家文化中晚期(4200~3800 a B.P.)和辛店文化时期(3400~2700 a B.P.)人类频繁放火烧荒和开垦农田以及生活等活动的结果;而3850~3600 a B.P.阶段以焖烧为特征的低强度野火发生,与气候持续干旱和人类森林砍伐活动加剧有关。与此同时,该区域遭遇2次大规模的地震和山洪泥流地质灾害,生态环境恶化,使得农耕为主的齐家文化被半农半畜牧的辛店文化所替代,从而导致该期间炭屑通量整体下降。全新世晚期,气候进一步干旱,1500年以来本地大幅度生物质燃烧增加与农业扩张和耕地面积增大密切相关。总之,全新世中期先前人类长期频繁森林砍伐活动所诱发的低强度焖烧火模式是导致该区域植被减少和土地退化的不容忽视的重要因素,而东亚季风所控制的季节性降水变化仍是野火发生必要条件。展开更多
In the rotary kiln alumina production process, because of the complexity and variability of rotary kiln burning zone conditions, some important quality index related process parameters can not be detected continuously...In the rotary kiln alumina production process, because of the complexity and variability of rotary kiln burning zone conditions, some important quality index related process parameters can not be detected continuously on-line.Detecting the different burning zone conditions on-line is a key factor for the whole process automation of alumina industry. The current method depends on flame observation by naked eye.In order to realize automated recognition of burning zone conditions, a method which learned experience and knowledge from naked eye observation was proposed to recognize burning zone conditions by utilizing the image processing technique and pattern classification method.At first, features were extracted from flame images of rotary kiln burning zone and were combined with some important process parameters to constitute a hybrid feature vector.Then a model with a binary tree based SVM (support vector machine) was constructed.At last, a flame image recognition system was developed.The system was successfully applied to a domestic alumina plant, and good economic benefit was realized.展开更多
文摘由于不同燃烧指标存在明显的差异,致使人们对于火燃烧方式的理解尚不确定。本研究选取黄河上游青海上喇家典型剖面(深度464 cm,年代范围14.5~0 ka B.P.)为对象,结合炭屑和黑碳以及古生态指标,揭示该区域全新世以来的野火历史演变过程。研究结果表明末次冰期和全新世早期,气候较为干旱,以明烧为特征的草原区域野火时常发生,与东亚季风气候所控制燃料特征和湿度密切相关。全新世中期,气候较现在温暖而湿润,生物成壤作用强烈,该地区整体上自然野火发生处于较低水平。其中,4200~3850 a B.P.和3400~3000 a B.P.这两个阶段的粗颗粒炭屑通量峰值分别是齐家文化中晚期(4200~3800 a B.P.)和辛店文化时期(3400~2700 a B.P.)人类频繁放火烧荒和开垦农田以及生活等活动的结果;而3850~3600 a B.P.阶段以焖烧为特征的低强度野火发生,与气候持续干旱和人类森林砍伐活动加剧有关。与此同时,该区域遭遇2次大规模的地震和山洪泥流地质灾害,生态环境恶化,使得农耕为主的齐家文化被半农半畜牧的辛店文化所替代,从而导致该期间炭屑通量整体下降。全新世晚期,气候进一步干旱,1500年以来本地大幅度生物质燃烧增加与农业扩张和耕地面积增大密切相关。总之,全新世中期先前人类长期频繁森林砍伐活动所诱发的低强度焖烧火模式是导致该区域植被减少和土地退化的不容忽视的重要因素,而东亚季风所控制的季节性降水变化仍是野火发生必要条件。
文摘In the rotary kiln alumina production process, because of the complexity and variability of rotary kiln burning zone conditions, some important quality index related process parameters can not be detected continuously on-line.Detecting the different burning zone conditions on-line is a key factor for the whole process automation of alumina industry. The current method depends on flame observation by naked eye.In order to realize automated recognition of burning zone conditions, a method which learned experience and knowledge from naked eye observation was proposed to recognize burning zone conditions by utilizing the image processing technique and pattern classification method.At first, features were extracted from flame images of rotary kiln burning zone and were combined with some important process parameters to constitute a hybrid feature vector.Then a model with a binary tree based SVM (support vector machine) was constructed.At last, a flame image recognition system was developed.The system was successfully applied to a domestic alumina plant, and good economic benefit was realized.
