Real-Time Dynamic Hybrid Testing Coupling Finite Element and Shaking Table

In this article, a Simulink simulation block with the finite element function is developed on the basis of S-function and implemented as the numerical substructure of real-time dynamic hybrid testing. Thereby, a real-time dynamic hybrid testing system coupling finite element calculation and shaking table testing is achieved. Using the developed system, a shear frame mounted on the soil foundation is tested, in which the shear frame is simulated as the physical model and the foundation is simulated as the finite element model with 132 degrees of freedom. Several cases of the dynamic behavior of soil-structure interaction are studied.     

Fluid effect on hydraulic fracture propagation behavior: a comparison between water and supercritical CO2‐like fluid

The initiation of hydraulic fractures during fluid injection in deep formations can be either engineered or induced unintentionally. Upon injection of CO₂, the pore fluids in deep formations can be changed from oil/saline water to CO₂ or CO₂ dominated. The type of fluid is important not only because the fluid must fracture the rock, but also because rocks saturated with different pore fluids behave differently. We investigated the influence of fluid properties on fracture propagation behavior by using the cohesive zone model in conjunction with a poroelasticity model. Simulation results indicate that the pore pressure fields are very different for different pore fluids even when the initial field conditions and injection schemes (rate and time) are kept the same. Low viscosity fluids with properties of supercritical CO₂ will create relatively thin and much shorter fractures in comparison with fluids exhibiting properties of water under similar injection schemes. Two significant times are recognized during fracture propagation: the time at which a crack ceases opening and the later time point at which a crack ceases propagating. These times are very different for different fluids. Both fluid compressibility and viscosity influence fracture propagation, with viscosity being the more important property. Viscosity can greatly affect hydraulic conductivity and the leak‐off coefficient. This analysis assumes the in‐situ pore fluid and injected fluid are the same and the pore space is 100% saturated by that fluid at the beginning of the simulation.     

评迈内克的“国家理由”研究和马基雅维里的国家权力学说

本文主要评述历史学家迈内克在研究国家理由问题时所表现出的历史道德理想主义特点。正是这种理想主义导致迈内克对马基雅维里国家权力等思想的论述失之偏颇。因此,完整地分析、理解马基雅维里国家权力等思想的结构,这不仅对理解马基雅维里的国家理由观,还对理解学术界的各种国家理由批评有所裨益。     

10世纪前中国西北边疆发展的几个特点

10世纪前的中国西北边疆经历了开拓、稳定和演变等过程,构成了一个相对完整的发展阶段,边疆发展的各种形态与主要特点尽皆呈现。南农北牧既是西北边疆的基本经济形态,也是历史上中原农业王朝与北方游牧民族角逐态势延伸的主要依据;在作为边疆主体的中原或内地王朝、客体的西域地区和旁体的北方游牧民族等三个主要因素的共同作用下,西北边疆的政治地理范围时有伸缩,而多种统治体制并存、边疆问题与民族问题一体化等特点也贯穿于这一时期西北边疆发展的整个过程。     

20世纪博物馆藏品管理的理论与实践

藏品管理的理论研究与实际工作是一个不断实践、不断总结、不断完善的探索过程。20 世纪我国博物馆藏品管理的理论建设与实际工作,已经形成了较完备、系统的理论体系和科学全面的实践工作程序。     

谈和谐社会进程中大学生现代法律意识的培养

构建和谐社会进程中大学生现代法律意识教育存在的诸多问题不断凸现,影响了我国建设社会主义法治国家的进程。大学生在未来社会处于主导地位,发挥着主体的作用。从这个角度来说,探明大学生现代法律意识结构状况,研究如何培养大学生现代法律意识,对于中国的法治实践具有重大的现实意义和深远的历史意义。     

《唐才子传·戎昱传》笺证

昱,荆南人.美风度,能谈.少举进士,不上,乃放游名都.虽贫士,而轩昂,气不消沮.爱湖湘山水,来客.时李夔廉察桂林,寓官舍,月夜,闻邻居行吟之音清丽,迟明访之,乃昱也,即延为幕宾,待之甚厚.崔中丞亦在湖南,爱之.有女国色,欲以妻昱,而不喜其姓戎,能改则订议.     

《步辇图》题跋为李德裕作考述

一 故宫博物院藏《步辇图》是一幅流传有绪的历史名画,历来以为是唐初阎立本所绘.徐邦达先生主编《中国绘画史图录》上对此画是如此说明的:"唐阎立本步辇图卷(宋摹本)","设色画:唐太宗李世民接见西藏使臣禄东赞的一段故事.画中李世民乘坐着'步辇',由四宫女抬行.     

朱希祖史学略论

朱希祖是我国20世纪前期的一位重要史学家,在北京大学史学系、中央大学史学系担任系主任多年,为中国史学的近代化作出了贡献。他继承和发展了章太炎的史学思想,在许多史学领域均具有精深造诣。本文论述了他的史学成就,求真与致用相统一的史学思想以及他的治史特色、治史方法论。