中国科学院高能物理研究所提出了ERL-FEL(Energy recovery linac-Free electron laser)"一机两用"的概念,通过同一直线加速器将能量回收加速器(Energy recovery linac,ERL)和自由电子激光(Free electron laser,FEL)结合到一...中国科学院高能物理研究所提出了ERL-FEL(Energy recovery linac-Free electron laser)"一机两用"的概念,通过同一直线加速器将能量回收加速器(Energy recovery linac,ERL)和自由电子激光(Free electron laser,FEL)结合到一起。本文讨论ERL-FEL两用实验装置主体屏蔽设计中,利用离散抽样的方法实现多个损失源项的整合,在同一FLUKA用户程序中实现多源抽样,并将蒙特卡罗计算结果与各源项独立处理的累积结果进行对比。计算表明,两者的结果吻合较好。基于束流损失源项整体建模的方法适用于其他小型直线加速器的整体屏蔽计算,可方便在其他装置上扩展应用。展开更多
The strategic delineation of the urban development boundary(UDB)is an effective initiative for efficient land resource allocation and for facilitating planned urban development.To align with sustainable development ob...The strategic delineation of the urban development boundary(UDB)is an effective initiative for efficient land resource allocation and for facilitating planned urban development.To align with sustainable development objectives,UDB definitions have evolved to reconcile urban development with ecological preservation.This study presents a UDB delineation framework from an integrated perspective that incorporates both demand-oriented and comprehensive constraints.Specifically,the urban construction land demand area was estimated based on population projections,meanwhile,the ecological red line(ERL)was delineated and integrated into the evaluation of the construction land suitability.Subsequently,with the demand area as the simulation target and unsuitable areas as comprehensive constraints,the UDB was delineated by simulating future land use patterns.The proposed framework was applied to Wuhan,a rapidly urbanizing city in central China,where the delineation of the UDB serves the dual purpose of managing the rapid expansion of built-up land and achieving a harmonious balance between urban development imperatives and ecological protection goals.Moreover,based on the results and analysis,policy implications for the rational spatial planning of Wuhan were proposed,encompassing the spatial patterns and scientific decision-making in ecological conservation and urban development.The results demonstrate that the efficacy of adopting a comprehensive perspective in delineating UDB effectively reconciles the competing needs of urban development and conservation.The framework and the policy insights derived in this study could inform spatial planning efforts not only in Wuhan but also in other cities facing the dilemma of urban development and ecological protection.展开更多
文摘中国科学院高能物理研究所提出了ERL-FEL(Energy recovery linac-Free electron laser)"一机两用"的概念,通过同一直线加速器将能量回收加速器(Energy recovery linac,ERL)和自由电子激光(Free electron laser,FEL)结合到一起。本文讨论ERL-FEL两用实验装置主体屏蔽设计中,利用离散抽样的方法实现多个损失源项的整合,在同一FLUKA用户程序中实现多源抽样,并将蒙特卡罗计算结果与各源项独立处理的累积结果进行对比。计算表明,两者的结果吻合较好。基于束流损失源项整体建模的方法适用于其他小型直线加速器的整体屏蔽计算,可方便在其他装置上扩展应用。
基金National Natural Science Foundation of China,No.72174071。
文摘The strategic delineation of the urban development boundary(UDB)is an effective initiative for efficient land resource allocation and for facilitating planned urban development.To align with sustainable development objectives,UDB definitions have evolved to reconcile urban development with ecological preservation.This study presents a UDB delineation framework from an integrated perspective that incorporates both demand-oriented and comprehensive constraints.Specifically,the urban construction land demand area was estimated based on population projections,meanwhile,the ecological red line(ERL)was delineated and integrated into the evaluation of the construction land suitability.Subsequently,with the demand area as the simulation target and unsuitable areas as comprehensive constraints,the UDB was delineated by simulating future land use patterns.The proposed framework was applied to Wuhan,a rapidly urbanizing city in central China,where the delineation of the UDB serves the dual purpose of managing the rapid expansion of built-up land and achieving a harmonious balance between urban development imperatives and ecological protection goals.Moreover,based on the results and analysis,policy implications for the rational spatial planning of Wuhan were proposed,encompassing the spatial patterns and scientific decision-making in ecological conservation and urban development.The results demonstrate that the efficacy of adopting a comprehensive perspective in delineating UDB effectively reconciles the competing needs of urban development and conservation.The framework and the policy insights derived in this study could inform spatial planning efforts not only in Wuhan but also in other cities facing the dilemma of urban development and ecological protection.
