基于三维扫描模型的兵马俑足踝有限元分析

利用三维扫描技术获取兵马俑残片的三维点云数据,结合Geomagic Studio和Hypermesh建立高精度的兵马俑足踝残片三维实体网格模型。通过基于ABAQUS的重力作用下的有限元分析,研究足踝部分的Von Mises应力和变形特征,以确定足踝处的受力薄弱部位。为进一步探究模型各残片的最佳点云简化比例,采用点云简化模型进行相同工况的有限元分析,以验证点云简化的可靠性。结果表明:结构在重力作用下可保持安全稳定的状态,相对薄弱部位位于左腿足踝处;对于大部分残片,其最佳简化比例在60%～70%,简化后可有效缩短模型实体化处理时间;采用简化模型得到的有限元结果,其最大Mises应力相比于原始模型的误差小于15%,且应力云图和变形图形状接近,模型简化具有可靠性。     

一种油画颜料层裂纹的修复技术分析

油画颜料层裂纹是一种常见的病害类型,严重的裂纹会影响作品的视觉效果。裂纹修复所采取的措施应以缓解病害,延续寿命为目标,避免不当修复对其文物价值的改变。本研究通过红外光谱和便携式X荧光能谱分析,初步确定了裂纹产生的原因与材料技法和机械作用力有关,长期的温湿度波动则是最终形成老化裂纹的重要因素。对两类常见的裂纹加固方法比较后得出结论,色蜡改变了原画的光泽度和肌理层,动物胶调碳酸钙更适宜作为裂纹的填补材料。观察修复后的油画保存状况,发现经过修复的颜料层仍存在继续劣化的风险,必须维持保存环境的相对稳定,方可延长修复周期。     

南宁市房地产价格分布规律的机助制图研究与开发方向的探讨

南宁市房地产业经历了由沉寂、复苏、火爆到稳步发展的过程．各公司开发的房屋类型相近,但价格差异却很大,价格分布呈现明显的规律性：一是城市中心价格高,边缘与郊区价格低;二是东部城区价格高,西部城区价格低．主导价格分布规律的三大影响因子是地理位置、交通便捷程度和生态环境质量．南宁今后的房地产开发和城市规划建设一要顺应价格分布规律,优地优用、保障房地产开发的高效益;二要加强交通设施建设和环境保护．促进全市房地产的升值;三要因势利导,发展城市副中心,逐步形成多中心的城市建设格局。     

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.     

破土器、庖厨刀或铡草刀——长江下游新石器时代及早期青铜时代石器分析之二

三角形石刀是长江下游地区良渚文化和青铜时代早期文化的一种特殊形状的石器,其功能众说不一,不少考古学家认为它是作为农业工具使用的"破土器"。通过对浙江湖州毘山遗址出土的两件商代三角形石刀进行微痕分析,并与采用复制石器进行实验考古后所得到的微痕进行比较,可知,毘山三角形石刀不是"破土器",而可能是用来切断植物茎叶的铡刀。     

A Path to “Emergent Peace” in Northeast Asia: The Shadow of the Past Matters

This article explores the possibility of institutional multilateralism in Northeast Asia from the perspective of “emergent peace”. The main argument of the article is that a self-organising peace process arising from institutional multilateralism is constrained and enabled by the existing “morphogenetic fields”, the formative social spheres of collective action. Similar ideas or initiatives that are pursued by an agent/agents may result in different consequences depending on the characteristics of the morphogenetic fields. This argument is examined through two case studies. The first is Jean Monnet in Europe, who played a pivotal role in the establishment of the European Coal and Steel Community (ECSC), and the other is Ahn Jung-geun in Northeast Asia, who proposed the detailed ideas of pan-Asianism akin to Monnet but failed to play a role as an agent. The case studies demonstrate that the feature of the morphogenetic fields is determined by the characteristics of embedded agency at a critical juncture, while the agency is bounded by the particular spatial and temporal conditions of the morphogenetic fields. In search of an emergent peace process in Northeast Asia, this article particularly highlights the Six-Party Talks, arguing that they are a by-product of, and an alternative to, the San Francisco System.     

Ming dynasty maritime provisions transport during the second stage of the East Asian War (1597–98)

Abstract

This article discusses the issue of the Ming army's maritime shipping of supplies during the second stage of the East Asian War of 1597–8. Despite the lack of historical sources and difficulty in finding accurate numbers, Zhang Yangmeng's 張養蒙 memorials include records of maritime transport decisions, implementation, effectiveness, and limitations and are of great help to filling in the blank areas of research in Ming army logistics.     

让材料自己说话——浅论当前历史传记写作的一种趋势

《陈寅恪的最后二十年》、《顾颉刚和他的弟子们》、《束星北档案》等著作,代表了当前历史传记写作的一种趋势。《陈寅恪的最后二十年》的文本近似历史叙事散文;《顾颉刚和他的弟子们》的文本更接近史学论文;而《束星北档案》则类同电视记录片的文稿。这些著作共有的特点是:在修撰方式上,大量运用了第一手材料;在文本风格上,力求作品深入浅出、雅俗共赏;在写作理念上,坚持真实第一,尊重历史。这一趋势非常值得重视。     

跨国场域下的企业家精神、国家与社会网络：中国新移民的个案分析

以在新加坡的中国新移民企业家为个案,简要地讨论企业家和企业家精神的内涵及其在全球化时代的展延;分析了新移民企业家跨国知识与技术优势在新兴企业成长中扮演关键作用;论述了跨国移民企业家产生与发展的不可或缺的外在因素以及由此形成的双赢策略;进而阐述跨国性的理论架构如何有助于解释华人企业家在当代世界和中国社会经济发展中的作用。