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我国中学化学课程的百年进程:阶段演进与发展趋势
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作者 王晶莹 李佳 +1 位作者 陈怡 宋倩茹 《化学教学》 CAS 北大核心 2021年第9期15-20,共6页
为厘清我国中学化学课程的发展脉络,对百年来我国39份中学化学课程标准进行了二阶段文本分析:采用共现知识图谱梳理化学课程标准在各发展时期课程内核的演变规律,利用TFIDF数据挖掘方法深度揭示化学课程标准的纵向发展历程。我国中学化... 为厘清我国中学化学课程的发展脉络,对百年来我国39份中学化学课程标准进行了二阶段文本分析:采用共现知识图谱梳理化学课程标准在各发展时期课程内核的演变规律,利用TFIDF数据挖掘方法深度揭示化学课程标准的纵向发展历程。我国中学化学课程历经百年嬗变,可以分为基础和发展两大阶段,初创、成长、发展和创新四个时期,从聚焦单维学生到兼顾学科内建制,再从多维化学教学与知识体系回归学生主体。化学课程要形成多元包容的课程创生体系,关注素养时代化学教师队伍的建设,践行可持续发展的育人观。 展开更多
关键词 中学化学课程 课程标准 文本分析 课程发展
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A decoupled procedure for convection-radiation simulation in scramjets 被引量:6
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作者 wang jing ying GAO Zhen Xun +1 位作者 LEE Chun Hian ZHANG Hui Qiang 《Science China(Technological Sciences)》 SCIE EI CAS 2014年第12期2551-2566,共16页
Following an order analysis of key parameters, a decoupled procedure for simulation of convection-radiation heat transfer problems in supersonic combustion ramjet(scramjet) engine was developed. The radiation module o... Following an order analysis of key parameters, a decoupled procedure for simulation of convection-radiation heat transfer problems in supersonic combustion ramjet(scramjet) engine was developed. The radiation module of the procedure consisted of Perry 5GG weighted sum gray gases model for spectral property calculation and discrete ordinates method S4 scheme for radiative transfer computation, while the flow field was computed using the Favrè average conservative Navier-Stokes(N-S) equations, in conjunction with Menter's k-ω SST two-equation model. A series of 2D supersonic nonreactive turbulent channel flows of radiative participants with selective parameters were simulated for validation purpose. Radiative characteristics in DLR hydrogen fueled and NASA SCHOLAR ethylene fueled scramjets were numerically studied using the developed procedure. The results indicated that the variations of spatial distributions of the radiative source and total absorption coefficient are highly consistent with those of the temperature and radiative participants, while the spatial distribution of the incident radiation spreads wider. It also demonstrated that the convective heating is significantly affected by the complexity of the flow field, such as the shock wave/boundary layer interactions, while the radiative heating is simply an integral effect of the whole flow field. Although the radiative heating in the combustion chambers reaches a certain level, an order of magnitude of 10 k W/m2, it still contributes little to the total heat transfer(<7%). 展开更多
关键词 SCRAMJET radiative heating convective heating turbulent combustion decoupled procedure
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