On-line Model Updating in Hybrid Simulation Tests

Hybrid simulation has emerged as a relatively accurate and efficient tool for the evaluation of structural response under earthquake loading. In conventional hybrid simulation the response of a few critical components is obtained by testing while the numerical module is assumed to follow an analytical idealization. Where there is a much larger number of analytical components compared to the experimental parts, the overall response may be dominated by the idealized parts hence the value of hybrid simulation is diminished. It is proposed to modify the material constitutive relationship of the numerical model during the test, based on the data obtained from the physically tested component. An approach based on genetic algorithms is utilized as an optimization tool to identify the constitutive relationship parameters used in updating the numerical model. The proposed model updating approach is verified through two analytical examples of steel and reinforced concrete frames. The results show the effectiveness of the updating process in minimizing the errors, compared to the assumed exact solution.     

Displacement-Based Design of an Energy Dissipating System for Seismic Upgrading of Existing Masonry Structures

A displacement-based method for the design of an energy dissipating system is proposed in this article. The device, which is composed of added concrete walls equipped with hysteretic Added Damping and Stiffness (ADAS) dampers, is aimed at upgrading the seismic behavior of existing masonry structures. The design method is based upon a simplified model of the overall structure-dissipating system. The proposed displacement-based design procedure was tested by means of inelastic response-time history analyses considering different masonry structures. The results of the analyses were compared with the seismic behavior expected from the design.     

农业和文明起源

文明起源在考古学上是一个复杂的问题,牵涉到人类社会的许多方面。其中一个重要方面就是农业。本文试图强调农业对文明起源所起的推动作用,并提出一些有关农业考古的看法,希望对目前正在进行的中华文明探源工程和类似课题有所帮助。     

中国现代史学科体系的建立与发展——以王桧林主编的北京师范大学版《中国现代史》教材为例

中国现代史学科体系是在与党史和革命史体系逐渐区别开来的过程中初步确立和发展起来的。李新等人主编的《中国新民主主义革命时期通史》奠定了中国现代史的基本框架。王桧林主编的北京师大版《中国现代史》继承和发展了这一框架。它的撰写、修改、趋向完备是和中国现代史学科的形成密切结合着的,它所提出的“三条道路、两个斗争、一个结局”的中国社会的演变规律为史学界所公认,它为中国现代史学科体系的初步建立和发展做出了贡献。     

Britain,European Economic Community Enlargement,and ‘Decolonisation’ in Hong Kong, 1967–1973

Politicians and businesspeople in Hong Kong paid close attention to British efforts to join the European Economic Community (EEC). The British colony was exempted from most tariffs in Britain, an arrangement that could not survive EEC enlargement. EEC members were unwilling to extend to Hong Kong, a significant exporter of manufactured goods, the same trade preferences offered to other dependent territories. Instead, the unique provision the EEC made for the colony was limited inclusion into their Generalised System of Preferences scheme, which granted tariff concessions to developing countries. Historians of Hong Kong have shown how the colony experienced British imperial withdrawal in a number of ways, despite remaining under British rule until 1997. This article demonstrates that an important element is missing from this account: how global economic shifts led to an erosion of imperial ties. EEC enlargement from 1973 entailed the end of Hong Kong's privileged access to the British market, but for the colony, the importance of imperial economic links had already faded. At the same time, an assessment of Hong Kong's capacity to pursue favourable terms of trade in global markets independently from Britain offers a more tentative conclusion of the extent of the colony's autonomy.     

全面抗战前央地关系视域下的南京国民政府省制变革

全面抗战前南京国民政府省制变革是近代中国省制变革的一个重要历史阶段。这一时期,大体经历了南京国民政府初期的省区分治与权势平衡、二次北伐完成后关于省财权人事权和军事权的央地博弈与武力纷争、中原大战后集权与分治的微妙平衡三个阶段的演变。南京政府正常的省权制度变革无法有序展开,在体制内却只能依靠军事和战争手段解决。这是最下策之下策,而且无法真正有效解决省权过大问题。直到全面抗战前夕,省制变革一直成为牵引中国时局演化与社会变动的中枢和焦点问题。     

试论周代宗庙制度及其变迁

周人在战国以前没有毁庙制度,坚持践行宗庙都宫制。天子七庙制度可能是战国以降才逐渐确立的。两周姬姓诸侯多以所出之周王为庙尊太祖。     

菲律宾华商网络中“头家制度”的经济学探析(1834—1942)

论文借助“博弈论”工具,结合案例分析,探讨了自1834年马尼拉开港到1942年二战菲律宾沦陷期间,“头家制度”的形成及其稳定性。研究显示,“头家制度”是建立在血缘、地缘以及华商之间信任和利益关系基础上的,其与西方基于契约基础上的信用有着本质的区别。在“头家制度”中,通过委托各地的代理商,头家一方面获得了用以出口的产品,另一方面又将进口商品通过代理商顺利地销售到菲律宾各地,不仅解决了货物流通问题,而且有效降低了交易成本。“头家制度”与华商网络之间的良性互动,最终实现了菲律宾华商杰出的商业成就。由于菲律宾华商非常注重信用和长期利益,他们之间的商业联系牢固而稳定,这不仅有效降低了华商之间的交易成本,提高了商业活动的效率,而且最终形成了一个由马尼拉向菲律宾各地辐射的菲律宾华商网络。     

Late Ordovician and Early Silurian conodonts from the “Uralba Beds”, northern New South Wales

Limestone outcrops that form a north-south belt approximately 1.4 km long, 15 km east of Manilla and previously referred to as the Uralba Beds, and associated rocks, are shown to be an olistostromal component of the Wisemans Arm Formation. Elongate olistoliths up to 100 m in length are flanked by limestone conglomerate with clasts set in a volcaniclastic matrix derived from a range of volcanic rock types. Volcanic olistoliths, including a mass of ankaramitic basalt, are also present. Conodont faunas of differing ages were obtained from various outcrops. A Late Ordovician (Eastonian, Ea3) fauna of over 400 elements from some outcrops is identical to one recently documented from elsewhere in the Wisemans Arm Formation. A small Early Silurian (late Llandovery-early Wenlock) fauna from four outcrops (including two formerly thought to be Ordovician) comprises the first documented conodont fauna of this age from the New England Fold Belt.