Design Concept:Staggered Dwelling The maisonette system,inspired by Le Corbusier’s concept of linking vertical cores and a central corridor,has been incorporated in this model. Aimed at benefiting both the developer ...Design Concept:Staggered Dwelling The maisonette system,inspired by Le Corbusier’s concept of linking vertical cores and a central corridor,has been incorporated in this model. Aimed at benefiting both the developer and home owner,the concept focuses on a staggered truss system which was chosen for its flexibility, lower construction costs,and significant design flexibility.The staggered truss system has reduced the total cost of the structure due to steel’s lighter frame and fewer foundations.Further savings were accrued because the building required fewer columns and less steel tonnage.The design has eliminated interior columns to create open space.设计理念:交错式住房这个模型采用了受启发于Le Corbusier的连接垂直内核和中央走廊概念的小户型结构。旨在造福开发商和业主,该概念主要采用交错桁架体系,它具有灵活、建设成本低和显著的设计灵活性等优点。由于较轻的框架和较少的基础,交错桁架体系结构总的成本已得到降低。建设中因采用更少的柱子和钢材,可进一步节约成本。设计消除了内柱,可为住户营造一个更开阔的空间,见图1。展开更多
针对时间尺度及其转换方法进行了综述、归纳和分类。从建立的基础出发,将时间尺度划分为原子时尺度和世界时尺度2个大类,其中,原子时尺度的彼此转换基于广义相对论框架,世界时尺度的彼此转换基于地球自转和岁差章动模型,而协调世界时是...针对时间尺度及其转换方法进行了综述、归纳和分类。从建立的基础出发,将时间尺度划分为原子时尺度和世界时尺度2个大类,其中,原子时尺度的彼此转换基于广义相对论框架,世界时尺度的彼此转换基于地球自转和岁差章动模型,而协调世界时是连接这2类时间尺度的桥梁。根据各类时间尺度间的转换公式,计算了原子时彼此间的差值序列,以及世界时在IERS(International Earth Rotation and reference systems Service,国际地球自转与参考系服务)1996、2003、2010这3个规范间的差值序列,并分析了这些差值序列的特征。结果表明:地心坐标时与质心坐标时、质心坐标时与质心力学时、地球时与地心坐标时之间的差值序列均随时间呈线性变化关系,且后者差值的增幅远小于前2个差值的增幅;协调世界时与国际原子时之间的差值是不连续的,且增幅逐渐减小;地球时与质心力学时之间的差值序列是以年为周期进行变化的,差值大小在±1.7 ms以内;格林尼治(平)恒星时、赤经章动及其补充项在IERS 2003、2010规范间的差异较小,而在IERS 1996与另外2个规范间的差异较大。这些结论可为相关研究及工程计算中的时间尺度选取提供参考依据。展开更多
This special issue consists of 12 invited reviews on the frontier areas of as- tronomy and astrophysics, and is aimed at a timely, in-depth evaluation of the current status and key progress, with suggestions for futur...This special issue consists of 12 invited reviews on the frontier areas of as- tronomy and astrophysics, and is aimed at a timely, in-depth evaluation of the current status and key progress, with suggestions for future directions. This special issue is particularly dedicated to the IAU XXVIIIth General Assembly （GA） and is complementary to the IAU GA Invited Discourses during the conference.展开更多
SN1997br is one of the supernovae discovered by the Beijing Observatory. The photo on the left is the image of the extragalaxy ESO 1318-2147 before the outbreak of the supernova and on the right is the image of the di...SN1997br is one of the supernovae discovered by the Beijing Observatory. The photo on the left is the image of the extragalaxy ESO 1318-2147 before the outbreak of the supernova and on the right is the image of the discovered supernova with its location indicated by an arrow. SN 1997br belongs to a special kind of la-type supernovae. Our research of them is of special importance in advancing our cosmological knowledge.展开更多
文摘Design Concept:Staggered Dwelling The maisonette system,inspired by Le Corbusier’s concept of linking vertical cores and a central corridor,has been incorporated in this model. Aimed at benefiting both the developer and home owner,the concept focuses on a staggered truss system which was chosen for its flexibility, lower construction costs,and significant design flexibility.The staggered truss system has reduced the total cost of the structure due to steel’s lighter frame and fewer foundations.Further savings were accrued because the building required fewer columns and less steel tonnage.The design has eliminated interior columns to create open space.设计理念:交错式住房这个模型采用了受启发于Le Corbusier的连接垂直内核和中央走廊概念的小户型结构。旨在造福开发商和业主,该概念主要采用交错桁架体系,它具有灵活、建设成本低和显著的设计灵活性等优点。由于较轻的框架和较少的基础,交错桁架体系结构总的成本已得到降低。建设中因采用更少的柱子和钢材,可进一步节约成本。设计消除了内柱,可为住户营造一个更开阔的空间,见图1。
文摘针对时间尺度及其转换方法进行了综述、归纳和分类。从建立的基础出发,将时间尺度划分为原子时尺度和世界时尺度2个大类,其中,原子时尺度的彼此转换基于广义相对论框架,世界时尺度的彼此转换基于地球自转和岁差章动模型,而协调世界时是连接这2类时间尺度的桥梁。根据各类时间尺度间的转换公式,计算了原子时彼此间的差值序列,以及世界时在IERS(International Earth Rotation and reference systems Service,国际地球自转与参考系服务)1996、2003、2010这3个规范间的差值序列,并分析了这些差值序列的特征。结果表明:地心坐标时与质心坐标时、质心坐标时与质心力学时、地球时与地心坐标时之间的差值序列均随时间呈线性变化关系,且后者差值的增幅远小于前2个差值的增幅;协调世界时与国际原子时之间的差值是不连续的,且增幅逐渐减小;地球时与质心力学时之间的差值序列是以年为周期进行变化的,差值大小在±1.7 ms以内;格林尼治(平)恒星时、赤经章动及其补充项在IERS 2003、2010规范间的差异较小,而在IERS 1996与另外2个规范间的差异较大。这些结论可为相关研究及工程计算中的时间尺度选取提供参考依据。
文摘This special issue consists of 12 invited reviews on the frontier areas of as- tronomy and astrophysics, and is aimed at a timely, in-depth evaluation of the current status and key progress, with suggestions for future directions. This special issue is particularly dedicated to the IAU XXVIIIth General Assembly （GA） and is complementary to the IAU GA Invited Discourses during the conference.
文摘SN1997br is one of the supernovae discovered by the Beijing Observatory. The photo on the left is the image of the extragalaxy ESO 1318-2147 before the outbreak of the supernova and on the right is the image of the discovered supernova with its location indicated by an arrow. SN 1997br belongs to a special kind of la-type supernovae. Our research of them is of special importance in advancing our cosmological knowledge.
