Let M f be the Kakeya maximal function in d-dimensional Euclidean space, with same base consisting of cylinders of eccentricity N. The inequality shoum for a base satisfying a direction condition, where ?and c are con...Let M f be the Kakeya maximal function in d-dimensional Euclidean space, with same base consisting of cylinders of eccentricity N. The inequality shoum for a base satisfying a direction condition, where ?and c are constants depending only on d.展开更多
Ultra-high strength special steels and wrought Ni-base superalloys are been ever increasingly applied in aircraft and aerospace,power generation,oil-gas and other industries.The development of those materials is drive...Ultra-high strength special steels and wrought Ni-base superalloys are been ever increasingly applied in aircraft and aerospace,power generation,oil-gas and other industries.The development of those materials is driven by tougher working conditions,higher efficiency,environment consideration,resource limitation and cost reduction. This presentation will focus on the development of ultra high strength special steels and wrought Ni-base superalloys in aircraft industry. The examples of ultra-high strength steels include: (1) Ultra-high strength stainless steels for landing gear and other structures; (2)High speed and high temperature main shaft bearing steels; (3) Ultra-high strength steels for jet engine main shaft. New and modified Ni-base superalloys will be discussed by examples of (1 )Low cost,process-friendly superalloys with higher performance; (2)Modification of hard-to-processed superalloys. Future development of those materials will be addressed.展开更多
目的 探究基于图片存档及通信系统(picture archiving and communication system,PACS)的翻转课堂教学在神经外科专科医师规范化培训(简称“专培”)实习中的效果。方法 选取2019年6月—2022年6月重庆医科大学附属永川医院60名在神经外...目的 探究基于图片存档及通信系统(picture archiving and communication system,PACS)的翻转课堂教学在神经外科专科医师规范化培训(简称“专培”)实习中的效果。方法 选取2019年6月—2022年6月重庆医科大学附属永川医院60名在神经外科实习的专培生,随机分为观察组和对照组,各30名。其中对照组采用常规传统教学法,观察组采用基于PACS系统的翻转课堂教学法。评估两组专培生实习期间出科考试成绩以及教改实践效果。结果 观察组理论考试成绩、实践技能成绩、综合测评总成绩均高于对照组,差异有统计学意义(P <0.05)。观察组提高学习效率、提升自学能力、促进实习参与意识、增进临床思维能力、提高信息获取能力、提高学习效率、提高临床实践技能均优于对照组,差异有统计学意义(P<0.05)。结论 将基于PACS系统的翻转课堂应用于神经外科专培生的实习中,可有效激发专培生的自主学习能力,提高出科考试成绩,同时提升专培生的实践教学效果,为临床培育更优秀的神经外科医生。展开更多
This study examines the design provisions of the Chinese GB 50011-2010 code for seismic design of buildings for the special boundary elements of T-shaped reinforced concrete walls and proposes an improved design metho...This study examines the design provisions of the Chinese GB 50011-2010 code for seismic design of buildings for the special boundary elements of T-shaped reinforced concrete walls and proposes an improved design method. Comparison of the design provisions of the GB 50011-2010 code and those of the American code ACI 318-14 indicates a possible deficiency in the T-shaped wall design provisions in GB 50011-2010. A case study of a typical T-shaped wall designed in accordance with GB 50011-2010 also indicates the insufficient extent of the boundary element at the non-flange end and overly conservative design of the flange end boundary element. Improved designs for special boundary elements ofT-shaped walls are developed using a displacement-based method. The proposed design formulas produce a longer boundary element at the non-flange end and a shorter boundary element at the flange end, relative to those of the GB 50011-2010 provisions. Extensive numerical analysis indicates that T-shaped walls designed using the proposed formulas develop inelastic drift of 0.01 for both cases of the flange in compression and in tension.展开更多
基金The author is partly supported by the Grants-in-Aid for Scientific Reseach,The Ministry of Educa-ion,Science and Culture,Japan.
文摘Let M f be the Kakeya maximal function in d-dimensional Euclidean space, with same base consisting of cylinders of eccentricity N. The inequality shoum for a base satisfying a direction condition, where ?and c are constants depending only on d.
文摘Ultra-high strength special steels and wrought Ni-base superalloys are been ever increasingly applied in aircraft and aerospace,power generation,oil-gas and other industries.The development of those materials is driven by tougher working conditions,higher efficiency,environment consideration,resource limitation and cost reduction. This presentation will focus on the development of ultra high strength special steels and wrought Ni-base superalloys in aircraft industry. The examples of ultra-high strength steels include: (1) Ultra-high strength stainless steels for landing gear and other structures; (2)High speed and high temperature main shaft bearing steels; (3) Ultra-high strength steels for jet engine main shaft. New and modified Ni-base superalloys will be discussed by examples of (1 )Low cost,process-friendly superalloys with higher performance; (2)Modification of hard-to-processed superalloys. Future development of those materials will be addressed.
文摘目的 探究基于图片存档及通信系统(picture archiving and communication system,PACS)的翻转课堂教学在神经外科专科医师规范化培训(简称“专培”)实习中的效果。方法 选取2019年6月—2022年6月重庆医科大学附属永川医院60名在神经外科实习的专培生,随机分为观察组和对照组,各30名。其中对照组采用常规传统教学法,观察组采用基于PACS系统的翻转课堂教学法。评估两组专培生实习期间出科考试成绩以及教改实践效果。结果 观察组理论考试成绩、实践技能成绩、综合测评总成绩均高于对照组,差异有统计学意义(P <0.05)。观察组提高学习效率、提升自学能力、促进实习参与意识、增进临床思维能力、提高信息获取能力、提高学习效率、提高临床实践技能均优于对照组,差异有统计学意义(P<0.05)。结论 将基于PACS系统的翻转课堂应用于神经外科专培生的实习中,可有效激发专培生的自主学习能力,提高出科考试成绩,同时提升专培生的实践教学效果,为临床培育更优秀的神经外科医生。
基金International Science&Technology Cooperation Program of China under Grant No.2014DFA70950Tsinghua University Initiative Scientific Research Program under Grant No.2012THZ02-1National Natural Science Foundation of China under Grant No.91315301
文摘This study examines the design provisions of the Chinese GB 50011-2010 code for seismic design of buildings for the special boundary elements of T-shaped reinforced concrete walls and proposes an improved design method. Comparison of the design provisions of the GB 50011-2010 code and those of the American code ACI 318-14 indicates a possible deficiency in the T-shaped wall design provisions in GB 50011-2010. A case study of a typical T-shaped wall designed in accordance with GB 50011-2010 also indicates the insufficient extent of the boundary element at the non-flange end and overly conservative design of the flange end boundary element. Improved designs for special boundary elements ofT-shaped walls are developed using a displacement-based method. The proposed design formulas produce a longer boundary element at the non-flange end and a shorter boundary element at the flange end, relative to those of the GB 50011-2010 provisions. Extensive numerical analysis indicates that T-shaped walls designed using the proposed formulas develop inelastic drift of 0.01 for both cases of the flange in compression and in tension.
