巨型框架-核心筒结构地震剪力分布特征分析

目前,我国在巨型框架-核心筒结构体系的工程设计中主要参照现行规范对于普通框架-核心筒结构的相关规定执行。然而,巨型框架-核心筒结构与普通框架-核心筒结构的受力特点及规律有所不同,针对巨型框架-核心筒结构与普通框架-核心筒结构的框架剪力分布特征的对比研究有待完善,而且我国现行规范也缺乏对巨型框架-核心筒结构中框架剪力的调整规定。因此,通过典型普通框架-剪力墙与巨型框架-剪力墙平面模型算例的静力分析及典型巨型框架-核心筒结构算例的弹塑性动力时程分析,考察了地震作用下楼层剪力在结构各竖向构件之间的分布规律。结果表明：地震作用下巨型框架-核心筒结构中的框架楼层剪力分布规律与普通框架-核心筒结构有明显区别;巨型框架柱与次框架柱的楼层剪力分布规律存在明显差异;规范中规定的框架剪力调整方法不能直接应用于巨型框架-核心筒结构。结合分析得到的剪力分布规律及已有的工程经验,针对巨型框架-核心筒结构中框架剪力调整方案进行讨论并给出相关建议。     

适合我国抗震设计规范的地震动选择

考虑反应谱特征周期的物理意义及结构的动力特性的影响,提出适用于我国规范的地震动选择方法。重点控制地震动反应谱特征周期与规范反应谱特征周期相一致,将T_g~6s周期段划分为6个拟合区间及对应的选择区间。并以我国规范时程分析的要求为评价原则,选取3个典型的中高层建筑进行动力时程分析,评估新方法的优劣。结果表明新方法选取地震动记录效果较好,对不同结构都有较强的适用性。     

从遗存到遗产：工业遗址景观化发展研究概述

文艺复兴以来,古遗址美学的发现与发展为工业遗址价值识别奠定了美学基础。随着传统工业逐渐退到历史的幕后,工业遗址凭借其崇高美特征被人们发现其文化价值内涵,并由此诞生了“工业考古学”。工业遗址逐步由工业纪念物发展到工业遗产,从单纯的审美载体转变为地区乃至国家文化遗产的重要组成部分。工业遗址具有再开发利用的巨大潜质,景观化则是其进行保护与再利用的重要手段。工业遗址景观化的实践大致经历了4个阶段:1)“如画式”处理采石场的工业改造开端时期;2)大地艺术拓展并运用纪念碑视角的工业纪念物时期;3)“博物馆化”风潮下景观设计受限的工业遗产提出时期;4)风景园林主导的整体保护与分层活化的工业景观时期。最后,针对价值理念之传播、法律机制之建立和活态可持续之发展几个方面,对工业遗址景观化发展提出了建议与展望。通过可持续、有机且综合的风景园林手段,将见证工业遗址作为遗产的可变价值。     

碳纤维布加固木结构古建筑弹塑性动力时程分析

根据课题组进行的碳纤维布加固残损木结构振动台试验,采用ANSYS有限元软件,建立了能真实反映其受力性能的有限元模型,通过对其进行弹塑性动力时程分析,得出了加固模型的结构动力特性以及在各种工况作用下的位移最大响应值和加速度最大响应值,求解出了结构各减震层的动力放大系数,并将振动台试验数据与数值模拟结果进行比较。研究表明:加固模型的第一频率为1.325 Hz,有限元模型的自振频率略低于振动台试验整体结构模型的自振频率;随着地震动强度的不断增加,模型各特征点的峰值位移随之增大,柱脚的位移响应值最小,柱头和乳栿顶面的位移差值不大;随着地震动强度的增加,模型各特征点的加速度响应值也逐渐变大,各层的动力放大系数越来越小;通过将有限元模拟的结果与试验结果对比分析得出,有限元计算值与试验值基本吻合,误差在工程允许范围之内,证明了所建有限元模型的合理性。     

明辽东海防军事聚落与长城军事聚落比较研究

通过对比分析明代辽东内陆防御体系(长城)和沿海防御体系在功能作用、布局因素和建筑形制等方面的异同,探寻二者的共性和特殊性,从而更加深刻地揭示了明代辽东海防军事聚落的建制体系、布局特征、功能作用和形制特色。     

苏联专家对新中国城市规划工作的帮助——以西安市首轮总规的专家谈话记录为解析对象

以"一五"时期西安市首轮城市总体规划为例,通过对苏联专家谈话记录进行深入解析,再现了苏联专家对我国城市规划工作进行帮助的鲜活事实。苏联专家对我国城市规划工作的帮助,既有城市规划的基本依据和规划原则等指导思想的明确,也有城市规划的科学基础、标准定额、设计方法和成果规范等工作内容的指导,还有签订协议文件等制度建设方面的建议。苏联专家对规划工作的帮助是全面、系统而深入的,兼顾了理论和实践、远景和近期、苏联经验和中国实际等多方矛盾,体现了科学、严谨而务实的态度。在对建国初期城市规划事业创立和发展的认识方面,应对苏联专家的重要贡献予以客观评价。     

Chinese state and society in epidemic governance: A historical perspective

This paper looks at the role of state and society in the history of epidemic governance in China for an appreciation of the way China manages the current COVID-19 epidemic.     

Itinerarium Wittichi ex Calendarium Sculteti: New biographical evidence on the Breslau mathematician Paul Wittich (ca. 1546–ca. 1587)

In the present paper, I present and discuss some new information about the life of Paul Wittich from Wrocław, Poland (formerly Breslau, Germany), an elusive mathematician and astronomer of the late 16th century. Wittich seems to have played a significant role in the emergence of two important, though short-lived, developments of late 16th-century science: the so-called prosthaphaeresis calculating method, and the geoheliocentric model of the universe usually attributed to Tycho Brahe. His role in both achievements, however, has not been sufficiently explained so far, and it is my belief that one of the main obstacles to that endeavor has been our scarce knowledge about the details of Wittich's life. Thus, I attempt to reconstruct his life with aim of being able to evaluate, eventually, his involvement in the development of mathematics and astronomy towards the end of the 16th century, primarily with the use of whatever scant sources can be found concerning Wittich. The source that I present here—a notebook of Bartholomäus Scultetus, an astronomer from Görlitz—is known and has already been used, but only to a limited extent by the community of historians of science, or by those of astronomy and mathematics. By presenting the information about Wittich from Scultetus's notebook, I aim to bring this source to the attention of those communities, clarify some hitherto unclear details from Wittich's life, and set out new paths for further investigation into his biography.     

Thermal history and its implications: A case study for ion exchange

Glasses containing monovalent species can be chemically strengthened by the replacement of smaller ions in the glass with larger external ions in the near glass surface. This type of ion exchange puts glass surface under high compressive stress (CS). Glass mainly fails from tension with the presence of surface flaws. Chemical strengthening can change the stress at the flaw tip from tension to compression and further stop the flaw from propagating. Glass damage resistance is therefore significantly improved. For the same glass composition, glass thermal histories can affect the magnitude and depth of the CS generated during ion exchange. In this study, the impact of thermal history on glass physical properties and ion exchange attributes in one alkali-containing glass formed by fusion draw process was investigated. Multiple thermal treatments were done to rewrite the glass thermal histories. Glass density, refractive index, and ion-exchange properties as a function of the thermal treatment were studied. It is concluded that ion exchange-related properties change dramatically with the glass thermal history.