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复合推进剂弹道特性的配方调节研究(英文) 被引量:1
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作者 muhammad mazhar iqbal 汪亮 《含能材料》 EI CAS CSCD 2006年第2期81-85,共5页
实验研究了含铝AP/HTPB推进剂的配方,讨论了燃速及压力指数与配方参数的关系。结果表明,推进剂燃速随平均AP粒子直径的增大而降低,但在大直径范围,这种趋势减缓。液体二茂铁催化剂可提高50%的推进剂燃速,而固体氧化铁可提高22%。液体二... 实验研究了含铝AP/HTPB推进剂的配方,讨论了燃速及压力指数与配方参数的关系。结果表明,推进剂燃速随平均AP粒子直径的增大而降低,但在大直径范围,这种趋势减缓。液体二茂铁催化剂可提高50%的推进剂燃速,而固体氧化铁可提高22%。液体二茂铁催化剂能比固体氧化铁更有效地提高燃速。燃速与压力指数的实验结果同燃烧模型的理论计算结果进行了比较,预估结果与实验数据符合较好。 展开更多
关键词 物理化学 复合推进剂 燃速 压力指数 催化剂 配方设计
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Estimation of infiltration models parameters and their comparison to simulate the onsite soil infiltration characteristics
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作者 Hafiz Umar Farid Zahid Mahmood-Khan +5 位作者 Ijaz Ahmad Aamir Shakoor muhammad Naveed Anjum muhammad mazhar iqbal muhammad Mubeen muhammad Asghar 《International Journal of Agricultural and Biological Engineering》 SCIE EI CAS 2019年第3期84-91,共8页
Detailed knowledge about soil characteristics and site-specific final steady infiltration rate could help to increase the irrigation water use efficiency and decrease water losses in agricultural system.The experiment... Detailed knowledge about soil characteristics and site-specific final steady infiltration rate could help to increase the irrigation water use efficiency and decrease water losses in agricultural system.The experiments were conducted on Agricultural Research Farm of Bahauddin Zakariya University,Multan,Pakistan during 2016.The cumulative infiltration depth was measured using double ring infiltrometer at selected six points of the study area.Most commonly used infiltration models such as Kostikov’s,Philip’s and Horton’s were fitted to the field infiltration data for determination of model parameters and to find the best fit model for the study area.Kostikov’s infiltration model’s parameters such as empirical constant‘c’and infiltration decay constants‘k’were obtained in the ranges of 0.140-0.290 and 0.307-0.433,respectively.Philip’s infiltration model’s parameters such as sorptivity‘S’and conductivity constant‘A’were found in the ranges of 0.167-0.288 cm/min1/2 and-0.001 to-0.009 cm/min,respectively.Similarly,the Horton’s model’s‘parameter‘k’was obtained in the range of-1.619 to-1.238.The value of infiltration capacity at onset of infiltration(fo)was obtained as 1.744 to 3.491 for all the six points.The analysis showed that the infiltration models using the estimated parameters have satisfactory prediction capability at all the selected points.Horton’s model provided the lowest mean values for RMSE(0.235)and highest mean values for ME(94%);and the lowest mean values for MPD(0.127).This indicated that infiltration can be well-described by the Horton’s model at the selected site. 展开更多
关键词 infiltration characteristics infiltration models parameters estimation perdition capability
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