乡村振兴视角下脱贫地区农村劳动力回流多维特征及形成机理——以重庆市奉节县为例

本文利用重庆市奉节县 390 个行政村（社区）调查数据及 5180 份农村劳动力抽样调查问卷数据,探究农村劳动力回流多维特征,运用二元 Lo‐gistic回归模型、地理探测器等方法,从个体和村域层面识别农村劳动力回流的内外源因素,并探究其作用机理。结果表明：①农村回流劳动力个体在性别、年龄、婚姻状况、家庭赡养抚养等方面表现出明显的差异性特征。②村域劳动力回流水平整体偏低,县域中部和南部较高,北部和中南部回流较低,表现出回流水平等级越高,空间集聚越不明显。③农村劳动力回流的内生性因素影响个体的回流能力和发展动力,而外源性因素决定劳动力的发展机会、生产生活条件和社会保障水平。     

MEASURING SUMMER SEA ICE SEVERITY IN EASTERN HUDSON BAY 1751–1870

The log-books of the Hudson's Bay Company supply ships are the sources from which are derived annual indices of summer sea ice severity in eastern Hudson Bay in the period 1751–1870. The indices are based on two properties of the daily ice conditions described in the log-books: lateness of occurrence and severity of ice. The annual ice index is obtained by comparing the ice conditions in each year from 1751 to 1870 with those in 1969. This year experienced the most severe late summer ice in this region during the period of present-day ice observations .
Les livres de bord des bateaux d'approvisionnement de la Compagnie de la Bale d'Hudson constituent les sources desquelles sont derives les indices annuels de sévérité de la glace marine estivale, dans la partie est de la Baie d'Hudson, pour la période 1751–1870. Ces indices de la glace sont établis à partir de deux propriétés des conditions quotidiennes de la glace, telles qu'elles sont décrites dans les livres de bord. Ces propriétés sont la tardiveté d'apparition et la sévérité de la glace. On obtient l'indice annuel de la glace en comparant les conditions de la glace pour chaque année de la période 1751–1870 avec les conditions de la glace en 1969. Cette année se charactérise par la glace d'été tardive la plus sévére dans cette région au cour de la période contemporaine d'observations de la glace .     

ON THE SEISMIC VULNERABILITY OF EXISTING UNREINFORCED MASONRY BUILDINGS

A large part of the building population in Switzerland is made of unreinforced masonry. For the assessment of the seismic risk the evaluation of the seismic vulnerability of existing unreinforced masonry buildings is therefore crucial. In this paper a method to evaluate existing buildings, which was developed for the earthquake scenario project for Switzerland, is briefly introduced and discussed in more detail for unreinforced masonry buildings. The method is based on a non-linear static approach where the seismic demand on the building is compared with the capacity of the building. In-plane and out-of-plane behaviour are considered. Comparisons with test results from model buildings show that the proposed method suitably forecasts the capacity of a building. Finally, a numerical example of the application of the method to a building in the city of Basel is given.     

OPTICAL DATING OF ANTHROPOGENIC SEDIMENTS AT THE ARCHAEOLOGICAL SITE OF HERRENBRUNNENBUCKEL,BRETTEN-BAUERBACH (GERMANY)*

Optical dating was applied to natural and anthropogenic silts at an Iron Age settlement in southern Germany. The natural sediments were dated accurately and allowed study of the human impact on the landscape. The studied anthropogenic sediments were infills of cellars and ditches. Again, deposits derived from soil erosion proved to be datable using infrared-optically stimulated luminescence. However, optical dating of fine grained sediments was at its limits when sediments consisted of a mixture of bleached and unbleached grains. This is shown on sediments of known age originating from cellar infills. Improvements were obtained when using the 560 nm emission and a partial bleach approach. Experimental evidence shows that the D_E versus shine-time plot discloses insufficient bleaching only in cases in which all grains are insufficiently bleached to the same degree.     

山东长清仙人台4号墓出土青铜盘的铸造工艺及相关问题

山东长清仙人台4号墓出土的青铜盘,在形制和装饰细节方面具有一定的地域特征。表面观察和X-CT技术分析发现,青铜盘的铸造工艺较为复杂,盘身与盘足、盘耳分铸而成,盘足、盘耳通过铸接、铸焊技术与盘身进行连接。与同时期其他青铜盘的工艺相比,仙人台青铜盘的铸造工艺具有鲜明的独特性,反映了工匠的独特匠心。这一发现和认识还一定程度上纠正了考古学“透物见人”相关论述中的群体偏好,有利于从“群体”和“个体”两个维度实现“透物见人”的学术追求。