A High-Performance Quadrilateral Flat Shell Element for Seismic Collapse Simulation of Tall Buildings and Its Implementation in OpenSees

Shear walls are important lateral force-resistant components of tall buildings. Hence, a reliable numerical model that can accurately represent the mechanical characteristics and large deformations of shear walls is critical for realistic collapse simulation of tall buildings. Based on the theory of generalized conforming element, a high-performance quadrilateral flat shell element, NLDKGQ, accounting for the large deformation using the updated Lagrangian formulation, is proposed herein and implemented in OpenSees. The reliability of NLDKGQ is validated using classical benchmark problems and reinforced concrete specimens. In addition, its capability in simulating the collapse of a tall building is also demonstrated.     

The impacts of parental migration on children’s subjective well-being in rural china: a double-edged sword

ABSTRACT

The emerging problem of left-behind children has attracted mounting academic and policy attention. Prior studies primarily cast light on left-behind children’s education, health, and behavior, while their subjective well-being is much less understood yet. Based on a nationally representative sample of rural children aged 10–15 in 2014, we examine the impacts of different types of parental migration on children’s subjective well-being and how these affects vary between boys and girls. The results show that parental migration is a double-edged sword: children from both-parent migrant families report compromised life satisfaction and relationship quality compared with those in integral families, and mother-only migration significantly lowers children’s subjective health. On the flip side, father-only migration enhances children’s aspiration for attaining college, an encouraging effect that is even stronger than that of parental education and family income. These effects are heterogeneous by children’s gender: boys seem to be more susceptible to the disruptive effects of both-parent migration; mother-only migration effectively promotes girls’ educational aspiration while father-only migration promotes boys’. This study portrays a comprehensive image of left-behind children. Relaxation of hukou restriction, equal access to education, and revitalization of rural economies are imperative to improve the well-being of left-behind children.

Abbreviations: LBC: Left-behing children; SWB: subjective well-being     

史家三巨擘 同门而异彩——傅斯年、范文澜、金毓黻的交往及学术人生论析

傅斯年、范文澜、金毓黻都是出身于北京大学国文门的著名史学家,都曾师从黄侃,得到黄侃的赞赏。但他们从北大毕业后,与黄侃关系亲疏不一。金毓黻与黄侃关系最笃,范文澜次之,傅斯年最淡。傅斯年、范文澜都有明确的政治立场,代表了史学发展之两翼,且在各自的学术机关居于领导地位。金毓黻与他们二人均有交往,对其学术亦有自己的评论,治学能谨守绳尺,本师说以为学,依违于二人之间。但国学功底深厚,重视民族气节以及对民族文化抱有深厚的情感,是他们立身行事以及学术著述的共同特点,反映了早年共同的师承对其学术的深层影响。     

贵州遵义杨粲墓出土地券的年代与性质

本文联系有关实物遗存和考古发现,提出贵州遵义南宋杨粲夫妇合葬墓附近所出石券,其年代并非南宋嘉定十七年(1224年),而是明世宗嘉靖二年(1524年);券石四周所刻用波浪形曲线相连之圆点,并非与天文星相有关之"星纹",而是川渝黔鄂地区宋元明墓葬较为流行之河图;该券并非生墓券,而是葬墓券;券主并非南宋杨粲夫人,而是明代嘉靖初年播州杨氏第二十七世土司杨斌之妻,生前因其丈夫身居三品之高位而被诰封为"淑人",死后皇帝遣官"谕祭旌表"。     

Influence of Taoism on the invention of the purple pigment used on the Qin terracotta warriors

Until the 19th century, most pigments were based on naturally occurring colored minerals and dyes, with three significant exceptions: Egyptian Blue, Chinese Blue/Purple and Maya Blue. The former two are alkaline-earth copper silicates, and because of this similarity it has been proposed that the Chinese pigments were derived from Egyptian Blue. Herein, we analyzed clumps of pigment from the Qin warriors and discovered that in spite of the structural similarity to Egyptian Blue, the micro-structural morphology of Chinese Purple is very different. Therefore, we believe that the synthesis technology for the Chinese pigments was a by-product of high-refractive index glasses (artificial jades) produced by Taoist monks. Further, the disappearance of these pigments from Chinese art and monuments concurrently with the decline of Taoism not only substantiates the link between the two, but also gives a striking example of how cultural changes in the society affected the scientific developments in ancient China.     

对西藏清代藏银铸币衡制与成色的疑问

衡制、平色是研究金属货币的基础和重要组成部分。关于清代西藏银币是否采用统一的货币计量衡制与平色说法不一。一说清代两藏地方政府铸造银币衡制均为中央库平,“两藏钱币自始至终所使用的衡制,与中央完全一致”。     

一部特色鲜明、内容丰富的续志——评《高青县志》(1978～2004)

《高青县志》（1978-2004）（以下简称《高志》）,系《高青县志》（1948-1985）的续志。该志客观、系统地记述了1978-2004年27年间高青县自然、政治、经济和化等方面的历史与现状,突出地展现了高青县改革开放以来所取得的发展变化。全志观点正确,体例严谨完备,篇章结构设计合理,层次比较清晰,地方特色和时代特征鲜明,资料翔实,装帧精美,是一部有特色、有创新、内容丰富的高质量续志。它在许多具体问题上的处理方式和方法也都比较得体,对第二轮修志工作具有积极的参考和借鉴意义。[第一段]     

萧何收集整理图书文献之功探微

文献是伴随着文化的创造而产生的。汉代的图书收集与整理主要是由汉武帝倡导,刘向、刘歆父子集大成,但不能忽视开国元勋萧何的奠基之功。文章从保护与利用、收集与创建等方面揭示了萧何对文献学及整个中华文化史作出的贡献。     

清代云南潞江流域瘴气分布区域初探

云南自古就是著名的瘴气之乡①。瘴气不仅分布范围大,存在时间较长,随社会历史发展及自然生态环境的变化而发生的变迁也经历了一个长期、渐变的过程,并对瘴区各民族的社会历史发展进程产生了重大影响。清代是中央王朝对云南边疆民族地区的统治和开发深入推进的时期,随地方文化事业的发展和方志纂修的兴盛、亲履瘴区人士的增多,云南瘴气得到了相对广泛和详细的记载,瘴气分布区也随生态环境的变迁逐渐被分割成一个个相对独立的小区域,这些区域交错集中于深山河谷中,纵贯于滇西、滇西南、滇南、滇东南的潞江、澜沧江、元江、南盘江流域等广大的…