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.     

明清学者论《旧唐书》署名问题辨正

《旧唐书》成书时,刘昫刚任"监修宰臣",于是《旧唐书》也就署名为"刘昫等纂"。不过这并非刘有意掠人之美为己有,而是当时的官方修史制度使然。明代中期以后,一些著名学者对《旧唐书》的这一署名形式产生了种种疑问,涉及到欧阳修的史德、刘昫对《旧唐书》编撰的贡献,以及《旧唐书》编修过程中的其他一些问题。但考察唐朝五代时期官方史学的发展实际可知,这些学者的论述皆有粗疏陋略乃至根本错误的地方,刘对《旧唐书》的编撰成功,起到了他作为第三任监修官的应有作用,《旧唐书》的署名形式并不存在任何问题。"刘"这一名称,已经不再只是代表他个人,而实际上成了《旧唐书》纂修队伍集体力量的代名词,成了《旧唐书》的代名词。对中国古代其他官修史书的署名情况,也必须作如是观,才不致被迷惑。     

读《全宋诗》札记四则

《全宋诗》是近年来古籍整理的一项重要成果,但其间也存在一些差错。卷三的“释印粲”条当删,卷四的徐铉小传中有一处标点有误,卷五误将两篇他人的诗作归于徐铉名下,卷一○在补录徐铉的诗作时未能引用出处最早的文献。     

Variability in the lithic and faunal record through 10 reoccupations of a XIX century Yamana Hut

The excavation of Tunel VII, a Yamana site dating to the indigenous/European contact period was part of a long term research project based on the north coast of the Beagle channel (Tierra del Fuego, Argentina). The aim was to evaluate the theory and methodologies and devise an archaeological method that would enable a complete picture of subsistence strategies to be constructed. At Tunel VII (a site with shell middens), we were able to analyse these strategies through 10 successive occupation events on a single location. Archaeozoological analysis of the faunal remains and use-wear analysis of lithic material were used to examine the management of resources. Production and consumption are two very useful concepts, and together they have been used to create a methodology, which, together with spatial analysis using significant variables, has enabled identification of recurrent or significant tendencies in relation to alteration or continuity in subsistence strategies. In the case of Tunel VII, we know that the people who continually occupied the hut were all from the same group.     

由"言今"到"证古"--从徐松看道光朝西北史地研究的一个侧面

渊源于新疆方志修撰的清代西北史地研究,在嘉庆末年至道光初年即表现出面向现实的特点。其中,龚自珍、魏源等人关注清政府西北统治政策的得当与否,而徐松等人则重在讲求西北山川形势的真实客观。道光中期以后,随着徐松等人在这一研究中的持续努力,西北史地研究转向对蒙元史及传统史志的研究,表现出由“言今”向“证古”的转变。     

试论许衡的历史思想

许衡从理学的基本命题出发,对社会历史的盛衰原因进行思考,他认识到历史变化的必然性以及盛衰治乱的对立统一关系。许衡将是否实行王道德治作为判断历史盛衰的标准,主张无论君臣都要“以公为心,以爱为心”,并阐明了一系列正君心、求民心的思想。许衡具有鲜明的通变史观,他结合当时的社会实际,总结历史经验,为元朝统治者论证了“行汉法”的必要性和具体内容。许衡论史而求理的思考,对于提高元代历史观的哲学思辨能力十分有益。他的历史思想对于元代多民族统一国家的建设具有积极的促进作用,也有利于蒙汉等多民族文化的不断融合与共同提高。     

Micromorphological perspectives on the stratigraphical excavation of shell middens: a first approximation from the ethnohistorical site Tunel VII,Tierra del Fuego (Argentina)

Due to their problematic stratigraphy, shell middens have traditionally been excavated by artificial stratigraphical cuts. This approach has often led to the obliteration of the original depositional sequence, removing important information regarding depositional and post-depositional processes, and human frequentation. Since the 1970s, an Argentinian team has been excavating archaeological shell middens in the Beagle Channel with a detailed stratigraphical approach, based on the excavation of actual depositional units (peeling), rather than artificial cuts. In the 1980s, Spanish archaeologists joined the Argentinean team and launched a series of new projects involving the excavation of ethnohistorical Yamana fisher-hunter-gatherer sites. The first excavated midden site was Tunel VII, from which two monolith columns of about 50 cm each (C11 and C12) that spanned the whole stratigraphy were extracted. The two columns were consolidated with resin, and two series of thin sections produced to corroborate stratigraphical observations made in the field, and to verify hypotheses related to the formation of archaeological shell midden sites. We present here the first results obtained from the microscopical observation of seven thin sections from column 11 (West column), extracted from a portion of the profile originally described as corresponding to the hut entrance and associated floor. The observation of microscopical features invisible in the field has provided supplemental information about the depositional and post-depositional processes affecting shell midden sites. We have also preliminarily defined a number of micromorphological characteristics identifying human activities such as discrete shell deposition events, phases of preparation of the hut floor, and compression by repeated trampling. Finally, we have explored the possibility of establishing some guidelines to characterise the length and character of frequentation phases of the site previous to its final abandonment at the beginning of the 20th century.     

略谈宋代官窑瓷器研究中存在的问题

宋代官窑是中国古陶瓷研究中的重要内容之一。长期以来,由于对相关历史文献的理解不同以及考古发掘的局限性,致使在宋代官窑瓷器研究中存在许多悬而未决的问题,诸如何为北宋官窑,北宋朝廷是否在都城汴京设置过官窑,北宋官窑是否就是汝窑,河南汝州张公巷窑是否是北宋官窑,南宋修内司官窑的称谓是否准确,南宋官窑是否只有郊坛下官窑一处,何为文献上所说的内窑,老虎洞窑是修内司官窑还是文献上所说的续窑,等等。本文在对专家学者们对上述问题的看法进行疏理的基础上,指出对宋代官窑瓷器的研究离不开传世宋代官窑瓷器、现代科学技术手段和考古发掘资料,只有将这三者结合起来开展综合研究,才能最终解决上述问题。     

沛国銍县徐氏考论

沛国銍县徐氏是我国历史上颇具影响的世家大族,它崛起于两汉之际,先祖徐宣任王莽讲学大夫,时逢国家以经义取士,徐宣及其子孙遂因累世经学而得累世公卿。汉魏鼎革,避乱南迁,改以医术名世,数代传承,家族医术取得了巨大成就,成为我国世家医术之杰出代表。又恰当社会崇尚黄老,重视养生,徐氏家族亦因累世医学而累世高官。本文在对徐氏家族居地移徙和成员履历行实考察的基础上,分析了该家族历二十一世数百年,人才辈出,绵延昌盛的原因,阐述了他们对我国中医学的贡献。     

Oxygen isotope seasonality in a temperate estuarine shell midden: a case study from CA-ALA-17 on the San Francisco Bay,California

Seasonality determination using stable oxygen isotope (δ¹⁸O) analyses in archaeological mollusk shell has been largely limited to aquatic settings where one of the two factors that control shell δ¹⁸O – water δ¹⁸O (or salinity) and temperature – is assumed to be constant. Open coastal marine environments reflect the former situation, and tropical estuaries constitute the latter. In an effort to expand stable isotope seasonality to an ecological setting where neither variable remains constant, we present a model of annual shell δ¹⁸O cycle of aragonite deposition derived from instrumental data on salinity and temperature from San Francisco Bay, California. The predicted range of modeled shell δ¹⁸O is consistent with observed δ¹⁸O values in prehistoric and modern shells when local conditions are considered. Measurements of δ¹⁸O taken at 0 mm and 2 mm from the terminal growth margin were made on 36 archaeological specimens of Macoma nasuta from a late Holocene hunter-gatherer site CA-ALA-17, and season of collection was inferred using the shell δ¹⁸O model. We conclude that shellfish exploitation occurred through the year with the exception of fall, which may indicate scheduling conflicts with acorn harvesting or other seasonally abundant resources elsewhere. The model supports the feasibility of stable isotope seasonality studies in temperate estuaries, provided that instrumental records are available to quantify the relevant water conditions at appropriate spatial and temporal scales.