采用锥形量热仪法研究磷氮硼基阻燃微胶囊处理中密度纤维板的动态燃烧行为.结果表明:阻燃中纤板与未阻燃处理的中纤板相比,热释放速率峰值从302.9 k W·m^(-2)下降到194.4 k W·m^(-2),总热释放量从119.7 MJ·m^(-2)下降到8...采用锥形量热仪法研究磷氮硼基阻燃微胶囊处理中密度纤维板的动态燃烧行为.结果表明:阻燃中纤板与未阻燃处理的中纤板相比,热释放速率峰值从302.9 k W·m^(-2)下降到194.4 k W·m^(-2),总热释放量从119.7 MJ·m^(-2)下降到83.2 MJ·m^(-2),生烟总量从2.2 m^2·m^(-2)下降到0.5 m2·m^(-2),极限氧指数最高值达45%,且纤板燃烧时的成炭率提高,炭层结构完整,强度高.表明磷氮硼基阻燃微胶囊能有效提高中密度纤维板的阻燃性能,展开更多
Thinning of Korean pine (Pinus koraiensis Sieb. et Zucc.) is used to facilitate timber and cone production. The present study in Northeast China investigated the effects of thinning intensity on individual tree growth...Thinning of Korean pine (Pinus koraiensis Sieb. et Zucc.) is used to facilitate timber and cone production. The present study in Northeast China investigated the effects of thinning intensity on individual tree growth, temporal variation in cone yield, and seed quality in Korean pine plantation. In 2005, five thinning intensity levels (none, extreme, heavy, moderate and light) were set in 15 permanent plots in a 32-year-old Korean pine plantation at Mengjiagang Forest Farm, Jiamusi City, Heilongjiang Province. We recorded tree growth and seed cone production from 2013 to 2016, i.e., from 8 to 11 years after thinning. Except for height growth, thinning increased tree growth (diameter at breast height and crown size) and improved cone yield. The extreme thinning treatment (to 300 trees per hectare) resulted in the largest tree diameter, tree volume, crown size and 4-year cone production per tree. The highest cone yield per tree in the mast year (2014) was observed when stands were thinned to 500 trees per hectare (heavy thinning). Although the best cone and seed quality and the largest cone and seed mass per tree were recorded in the heavily thinned stand, no significant differences were found between heavy and moderate thinning stands (750 trees per hectare). At the stand level, the moderately thinned stand had the highest basal area, stock volume and seed cone production per stand. Our results suggest that thinning to 750 trees per hectare will improve timber and cone productivity in 40-year-old P. koraiensis stands.展开更多
文摘采用锥形量热仪法研究磷氮硼基阻燃微胶囊处理中密度纤维板的动态燃烧行为.结果表明:阻燃中纤板与未阻燃处理的中纤板相比,热释放速率峰值从302.9 k W·m^(-2)下降到194.4 k W·m^(-2),总热释放量从119.7 MJ·m^(-2)下降到83.2 MJ·m^(-2),生烟总量从2.2 m^2·m^(-2)下降到0.5 m2·m^(-2),极限氧指数最高值达45%,且纤板燃烧时的成炭率提高,炭层结构完整,强度高.表明磷氮硼基阻燃微胶囊能有效提高中密度纤维板的阻燃性能,
基金supported by National Key R&D Program of China(2017YFD0600601)
文摘Thinning of Korean pine (Pinus koraiensis Sieb. et Zucc.) is used to facilitate timber and cone production. The present study in Northeast China investigated the effects of thinning intensity on individual tree growth, temporal variation in cone yield, and seed quality in Korean pine plantation. In 2005, five thinning intensity levels (none, extreme, heavy, moderate and light) were set in 15 permanent plots in a 32-year-old Korean pine plantation at Mengjiagang Forest Farm, Jiamusi City, Heilongjiang Province. We recorded tree growth and seed cone production from 2013 to 2016, i.e., from 8 to 11 years after thinning. Except for height growth, thinning increased tree growth (diameter at breast height and crown size) and improved cone yield. The extreme thinning treatment (to 300 trees per hectare) resulted in the largest tree diameter, tree volume, crown size and 4-year cone production per tree. The highest cone yield per tree in the mast year (2014) was observed when stands were thinned to 500 trees per hectare (heavy thinning). Although the best cone and seed quality and the largest cone and seed mass per tree were recorded in the heavily thinned stand, no significant differences were found between heavy and moderate thinning stands (750 trees per hectare). At the stand level, the moderately thinned stand had the highest basal area, stock volume and seed cone production per stand. Our results suggest that thinning to 750 trees per hectare will improve timber and cone productivity in 40-year-old P. koraiensis stands.
