故宫中和殿某中金檩断裂分析

勘查发现,故宫中和殿明间某中金檩在与上部爬梁相交位置出现局部断裂,造成下部中金枋产生较大挠度.为探明该中金檩产生断裂的原因,采取理论计算与数值模拟相结合的方法,对中金檩、中金枋体系进行了分析.基于榫卯连接边界条件的特征,分别考虑中金檩与中金枋叠合、中金檩与中金枋分离、中金檩完全断裂等三种工况,建立了中金檩-枋体系的受力模型,进行了静力分析,获得了中金檩、中金枋的变形及内力分布特征,讨论了中金檩断裂破坏的影响因素.结果表明:由于中金檩在爬梁作用位置截面削弱,造成中金檩自身拉、压、弯承载力不足,从而导致中金檩产生断裂;中金檩与中金枋分离条件下,中金檩断裂造成的中金枋内力增加,且比檩枋叠合条件更明显;中金檩完全断裂后,将造成中金枋内力及变形剧增,威胁中金枋安全.因此,对中金檩采取及时有效的加固措施极其重要.研究结果将为中金枋采取加固措施提供理论参考.     

微生物诱导矿化修复阿尔寨石窟红砂岩壁面酥碱病害试验研究

阿尔寨石窟寺是内蒙古地区规模最大且保存最为完整的石窟寺建筑群,其蕴含了珍贵的关于历史、宗教、科学、文化的艺术价值,被誉为“草原上的敦煌”。由于当地典型的沙旱寒区气候特征,酥碱成为石窟壁面最为严重的病害之一,目前阿尔寨石窟正处于保护阶段,因此通过室内对病害进行模拟和研究尤为重要。本研究通过微生物诱导碳酸钙沉淀(MICP)技术,对以红砂岩风化土为基质的壁面的酥碱病害进行修复,通过激光粒度分析了病害前后土颗粒粒径的变化,提出酥碱高度、酥粉体积、盐壳厚度的量化指标用以评价病害的发展程度。基于微生物矿化技术生成矿化覆膜对病害进行抑制,推荐使用微生物菌液浓度OD₆₀₀大于1.5的具有耐盐碱性能的矿化菌株,修复后酥碱高度下降幅度大于20%,酥粉体积下降幅度大于30%,盐壳厚度下降幅度大于25%。研究成果对生物矿化技术应用于红砂岩石窟壁面的酥碱病害的修复进行试验验证和可行性评估,为绿色生态环保的岩壁病害修复与加固技术的推广应用进行科学预研。     

景观资源量化评价的主要方法(模型)--综述及比较

本文根据国内外景观资源评价的最新研究成果,综合介绍了灰色聚类法、模糊综合法、价值工程法、综合指数法、可持续发展指数模型和元胞自动机模型等六种景观资源量化评价方法(模型)的基本原理及其应用,并对各模型的主要特征、适用范围等进行了比较研究。     

《明史·地理志》河南地理考误

张廷玉《明史·地理志》向以体例严谨、言简意明而著称,堪称正史地理志中的上乘之作。但其中的疏漏讹误似亦难免。以《地理三》及《地理一》、《地理二》中的河南地理为例,经据有关史料校读考证,中华书局点校本之相关部分尚有讹误40余处。其致误原由则不一而足。     

Court-day crowds in colonial Virginia

ABSTRACT

For a generation, legal historians investigating colonial Virginia have emphasized the dramaturgy of court day. According to the dramaturgical school of interpretation, administrative and judicial activities of county court officials amounted to theatrical performances that simultaneously enforced economic order and stabilized traditional social relationships. Such interpretations assume a large audience routinely attended county courts to observe legal dramas. Often, however, only a small number of persons can be documented as present during court day. The independence theorem from probability theory suggests that the number of documentable attendees is a useful and easily calculated estimate for actual total crowd size. If so, some Virginia court sessions were attended by hundreds of people, while others drew only a few participants. A variety of factors apparently inhibited court attendance in older Virginia counties. By contrast, in newer frontier counties, mid-eighteenth-century revisions of court calendars produced heavy attendance at court day. Regardless of the number of people in attendance, any Virginia county court could still effectively enforce credit contracts.     

Henry Herbert Donaldson’s (1857–1938) contribution to an organized approach to the experimental study of the mammalian central nervous system

ABSTRACT

This article shows that the academic and research careers of Henry Herbert Donaldson (1857–1938) were directed to provide basic information about the growth of the vertebrate nervous system and to provide standards and the means to make such research efficient. He earned the reputation of making the albino rat a standard laboratory animal. His academic career began when he was an undergraduate at Yale University in 1875 and concluded with his death as Professor and Head of the Department of Neurology at the Wistar Institute of Anatomy and Biology of the University of Pennsylvania in 1938. During that period, pivotal experiences occurred, including research in physiological chemistry with Chittenden at the Sheffield School at Yale, graduate study at Johns Hopkins University, postgraduate study in Europe, and professorial positions at Clark University and the University of Chicago. It was at Johns Hopkins University that Donaldson learned about the need for physiological, anatomical, and psychophysical research and about the techniques to allow such research. It was at Clark University that he had first-hand and detailed experience with the anatomy of the brain of a deaf-blind-mute woman, as he attempted to correlate her sensory deficits with her brain development. It was at Clark University that he clearly recognized the need for standardization in neurological research. At the University of Chicago, he developed administrative skills and began a coordinated research effort to delimit the growth of the nervous system. It was at Chicago that he learned that the albino rat could be a reasonable subject for such research. It was also at Chicago that he was able to formulate ideas about the future organizational needs of human neuroanatomy. It was at the Wistar Institute that his research program and his professional career matured. He organized a research effort to elucidate the growth of the nervous system. He contributed to the coordination of neurological research in the United States and Europe. It was while at the Wistar Institute that he became well-known for making the albino rat a standard laboratory mammal—a convenient living material for research.     

Is Q for you?: using Q methodology within geographical and pedagogical research

Q methodology is receiving growing interest as a research technique. Its use of factor analysis and a well-defined methodological approach may appeal to quantitative researchers who need to investigate issues more commonly associated with qualitative techniques. Such issues frequently arise when investigating student learning. This paper suggests that, appropriately used, Q is a methodology to be embraced by quantitative and qualitative researchers alike. Drawing on work within the field of education, as well as two case studies, the method's utility is illustrated, and Q is suggested as another potential method for investigating the subjective views of our students.     

Numerical simulations of amethyst geode cavity formation by ballooning of altered Paraná volcanic rocks,South America

Numerical modelling by finite element methods provides two significant insights into the formation of the giant amethyst geodes of the Paraná volcanic province: the conditions needed to open the cavities and the conditions that control their size and shape. Giant amethyst geodes were formed in the Cretaceous (135 Ma) in altered volcanic rocks by water vapour pressure (Δp) at about 0.5 MPa under an altered basalt cover of 5–20 m. Only rocks with Young’s modulus values (E) in the range 1–2 GPa can sustain ballooning, which is the growth of a cavity in a ductile medium by the pressure of water and its vapour. The size of the proto‐geode is dependent on the water vapour pressure, which is directly related to thickness of the overlying basalt. Varying the yield points causes the formation of either prolate or oblate cavities. A low transition point (smaller than 0.18 MPa) generates a prolate‐shaped cavity, whereas a high transition point (larger than 0.18 MPa) generates oblate proto‐geodes. Proto‐geodes are smaller when Young’s modulus is higher (rock is less altered) or when water vapour pressure is lower (because of thinner overburden of basalt). The calculations are an indication that the processes operative in the altered basalts led to the opening of giant cavities by ballooning.     

李雯为摄政王多尔衮捉刀致史可法书考论

李雯为清摄政王多尔衮捉刀致史可法之事,在清代朝野流传甚广,但迄今未能考实。本文博采明清史料及其同人文集之记载,又从李雯《蓼斋集》《蓼斋后集》入手,考察其代言写作之训练与降清之心态。综合内证与外证,确证《摄政王致史可法书》出自李雯之手。此文措辞简劲,理足神完,乃传世之名文。     

《商务谈判》在实践中的教学研讨

近年来社会对高校工商管理专业人才的需求趋势发生了改变,不但要求学生具有扎实的理论知识还特别强调学生具备较强的实践参与能力。《商务谈判》课程属于专业设置中的应用型专业课程,因而在新的就业形势下,教师在教学过程中应该改变以往重视理论而轻视实践的教学方式。本文针对课程教学中的实践环节的教学目标和要求,提出了教学方式和手段创新的具体方法,并介绍了在实际操作中的经验。