论我国现代货币单位"元、角、分"体系的确立

18世纪中叶以降 ,中国货币制度的近代化渐次展开。新的货币单位———“元、角、分”体系随之出现 ,在与传统货币单位的竞争中不断发展 ,1910年成为法定货币单位。通过北洋政府和国民党政府的努力 ,“元、角、分”体系的地位最终得以确立 ,并由中华人民共和国沿用至今     

Note on the Measurement of Spatial Imbalance

This note presents a new measure of spatial imbalance that uses the center of gravity (or the mean center) of a distribution and the geometric center (or the centroid) of a region to define a vector indicating the relative position of the distribution in the region. The spatial imbalance of a distribution in a region is defined as the distance and directional deviation of the center of gravity of the distribution from the geometric center of the region. The convex hull of a region is introduced as the reference for maximum spatial imbalance of the distribution in the region. The spatial imbalance is measured in terms of (1) the relative distance of the center of gravity between the geometric center and the convex hull; and (2) the direction from the geometric center to the center of gravity. This new measure is tested by quantifying the westward movement of the contiguous U.S. population between 1790 and 1950. It describes the well‐known observation that the U.S. population was moving westward across the contiguous United States and toward reduced spatial imbalance.     

明末清初皖北地区的秩序变乱与重建

明代皖北地区的地方政治呈现出以官府为主导的单轨特点,表面的稳定下蕴藏着变乱的隐患。明末战乱重创了官府权威,引发了空前的社会混乱,朝廷派遣官军进驻皖北,并在军事力量的支持下建立了战时统治秩序。依靠官军的保护,皖北州县有限地恢复了社会统治,但也因为供给军需、兵民冲突等问题,出现了新的社会危机。甲申之变后,弘光朝廷无法控制四镇军阀,皖北爆发兵乱,致使战时秩序崩塌、地方统治瓦解,民心士气亦由此尽丧。清军顺利占领皖北地区以后,凭借强大的国家机器重建了由官府权威主导的社会统治秩序,以相似的路径终结了明末以来的乱局,获得了民心的顺服。     

丹阳市三城巷遗址第二次发掘报告

2002年对三城巷遗址的第二次发掘发现了商周和新石器时期文化遗存,出土遗物有陶器、玉器、石器等,这次挖掘为研究宁镇地区古文化特点提供了重要资料。     

南京堂子街太平天国壁画再保护

为了使已经经历过保护修复的14幅南京堂子街太平天国时期的壁画能够更好地保存和展览,在全面的现场调查和修复资料收集的基础上,对壁画实施了现场预保护、搬迁以及实验室保护修复。采取了比较成熟的保护材料Paraloid B72、Primal AC33对壁画进行加固回贴;并将蒸汽清洗、激光清洗引入到壁画的表面清理中;同时改善了灌浆材料;采用了贴木浆纸、预先刷涂乙醇等改良工艺。在上述措施的综合使用下,壁画再次保护修复后效果良好。此保护修复方法可对类似需要再保护的壁画提供借鉴。     

城镇土地定级研究的几个问题——以西安市中心城市区为例

本文以西安市中心城市区土地定级为例,对城镇土地定级的理论和研究方法进行了较深入的研究、探讨,拓宽和深化了地理学、土地经济学的研究内容。为我国城镇土地定级研究工作的进一步开展提供重要依据。     

Micro-CT investigation of ostrich eggshell beads collected from Locality 12, the Shuidonggou site,China

Ostrich eggshell (OES) beads are an important kind of human ornaments, because their production reflects the development of modern human behavior, thinking ability, and cognitive level. Although the manufacture procedure of OES beads has been reconstructed in some Later Stone Age sites and early Neolithic sites, little information is known about detailed drilling technologies. In this study, synchrotron radiation micro-CT (SR-μCT) was firstly used to scan OES beads to understand microstructure, drilling marks, and perforation shape in a non-destructive mode. In contrast to other method to research drilling technologies, SR-μCT has a unique advantage that it could eliminate the influence of the adhering soils in a perforation in case that they are not easily removed. The results indicate that (1) SR-μCT could differentiate the eggshell species between Struthio camelus and Struthio anderssoni in terms of pore distribution. Compared to other destructive methods, including the anatomical method, DNA and protein analysis, the species identification through SR-μCT is non-destructive and faster; (2) the outer and inner surface of OES could be non-destructively judged according to OES microstructure, which would help infer the drilling direction; and (3) the perforation shape and drilling marks are distinct between the discontinuous twisting drilling and the multi-rotary drilling methods on the basis of replication experiments. According to these criteria, SR-μCT was applied to examine OES beads found in Locality 12 of the Shuidonggou (SDG) site in China, which were probably discarded in 1.1 k yr BP. The results show that most of ancient beads were firstly drilled from inside. According to the perforation shape and drilling marks, both the twisting drilling and the multi-rotary drilling method with different kinds of drill bits were used in working beads. Therefore, the people in SDG site mastered a few drilling technologies in the early Holocene, and the use of the multi-rotary drilling method reflects the technical development of ancient people. Up to our knowledge, it is the earliest known evidence of the application of the multi-rotary drilling method in China. Furthermore, this study will provide a new approach and important reference to understand drilling technologies of much older OES beads in the Later Stone Age or Upper Paleolithic Age.     

Influence of Time Step of Ground Motions on Site Effect and Structural Response Analyses for Long-Duration Earthquakes

Long-duration ground motions may be down-sampled to speed up the computational process. However, using ground motions with large time step (Δt) would inevitably bring in numerical errors. The influence of Δt on the site effect and structural response analyses was quantitatively examined in this study. The results show that the nonlinear site response method is more sensitive to a change of Δt than the equivalent-linear method. For the structural analysis, the impact of Δt is highly dependent on the magnitude of damage parameters. Thus, using input motions with Δt as 0.005 s is recommended for structures subjected to strong shakings.     

Beam-Column Joint Model for Nonlinear Analysis of Non-Seismically Detailed Reinforced Concrete Frame

An efficient and simplified plane beam-column joint model that can describe the strength deterioration, stiffness degradation, and pinching effect was developed for the nonlinear analysis of non-seismically detailed reinforced concrete frames. The proposed beam-column joint model is a super-element consisting of eight spring components and one panel zone component, representing the bond-slip mechanism of the longitudinal reinforcement and the shear deformation mechanism of the joint concrete core region, respectively. In order to represent the dynamic response at the system level, the elastic constitutive law is applied to the eight connector springs, while the Bouc-Wen-Baber-Noori (BWBN) model is adopted to describe the hysteretic behavior of the panel zone component. For the implementation of the finite element analysis, the algorithmically consistent tangent of the BWBN model is derived as a uni-axial constitutive model, while the initial stiffness of the panel zone component is determined by the concrete compression strut assumption. The accuracy and efficiency of the proposed beam-column joint model were calibrated at both the component and structural levels by comparing the simulated results with the experimental data for non-seismically detailed joint sub-assemblages and a reinforced concrete plane frame.