头部冠状位CT可调角度扫描架的研究

本文研究了头部冠状位ＣＴ可调角度扫描架的制做和应用。为了解决临床工作中头部冠状位ＣＴ扫描技术中存在的摆位困难，病人体位不舒适而移动所产生的定位不准确、图像不清晰、伪影等问题，着重介绍头部冠状位ＣＴ可调角度扫描架的固定作用和可调角度的研究．     

泥湾门大桥浅海大直径嵌岩桩施工技术

介绍了在浅海施工直径２．２０ｍ嵌岩桩的技术问题。包括平台的搭设，用刮刀钻头与牙轮钻头钻进克取硬岩一次成孔工艺，利用冲洗液平衡原理处理浅海钻进护简断裂的成孔方法，改进浇灌清孔流程，保证浇灌质量。     

大跨预应力混凝土空间框架结构的地震振动台试验研究

利用地震振动台对大跨预应力混凝土井式梁空间框架结构的抗震性能进行了实验研究。两个模型的实验结果表明：(1)大跨预应力井式梁空间框架结构可以提供大的楼层平面内刚度；(2)对称大跨预应力井式梁空间框架结构，可以不考虑耦合地震反应；(3)大跨预应力井式梁空间框架结构的竖向地震反应中心大而周边小；(4)在相同加速度但不同的地震波作用下，结构的竖向地震反应不同。     

倾斜基岩上的土-框架相互作用研究

倾斜基岩上的框架是山地、丘陵地区多见的一种结构形式，但以往对其抗震性能研究很少。本文利用二次开发后的ANSYS对倾斜基岩上的框架的抗震性能进行了上下部相互作用分析。在研究中发现，考虑土一结相互作用后，结构的高阶振型在地震反应中的参与程度提高；可能在结构的地震反应傅里叶谱中形成双峰；并使地震反应沿结构高度的分布不再沿直线变化，而呈锯齿状分布。由于倾斜基岩将降低土层对地震波的放大作用，但基本不改变地基的卓越频率，因此倾斜基岩将会抑制上部结构的地震反应；而倾斜基岩上结构的地震反应分布将比相应平坦基岩上结构的地震反应分布更接近直线形分布，但变化形状基本相同。     

填充墙与钢框架协同工作性能非线性分析

在试验研究的基础上，运用ANSYS有限元中的接触单元建模，对加气混凝土填充墙钢框架的结构性能进行了研究，同时与纯钢框架结构在强度、刚度、以及延性等方面进行了对比分析，结果表明：填充墙与钢框架协同工作能够改善钢框架结构的受力性能和抗震能力，这为钢结构及其围护体系的研究与推广应用提供了一定的理论依据。     

不同型式暗支撑短肢剪力墙抗震性能试验研究

本文选取短肢剪力墙结构体系中较为薄弱的抗震构件“一”形短肢剪力墙，采用不同的暗支撑型式进行了两个1／2缩尺的带暗支撑短肢剪力墙构件的低周反复荷载试验，比较分析了它们的承载力、刚度、延性、滞回特性、耗能能力及破坏机制，建立了其承载力计算模型与方法。计算结果与实测值符合较好。     

钢筋混凝土建筑抗倒塌设计

建筑抗倒塌问题近年来在欧美国家得到广泛关注，并颁布了相关的设计规范和标准。我国还没有制定有关建筑抗倒塌方面的规范和标准。本文提出一种基于建筑危险性的钢筋混凝土建筑抗倒塌设计方法。该方法将钢筋混凝土建筑分为四类，通过设置拉杆连接系统和Alternate Path设计提高建筑抗倒塌能力。     

A contribution to seismic shear design of R/C walls in dual structures

The paper focuses on the seismic response of walls in dual (frame + wall) structures, with particular emphasis on shear behaviour. Although dual structures are widely used in earthquake-resistant medium-rise and high-rise buildings, the provisions of modern seismic codes regarding design of walls for shear are not fully satisfactory, particularly in the (common) case that walls of substantially different length form part of the same structure. Relevant provisions of the leading seismic codes are first summarised and their limitations discussed. Then an extensive parametric study is presented, involving two multistorey dual systems, one with identical walls, and one with walls with unequal length, designed to the provisions of Eurocode 8 for two different ductility classes (H and M). The walls of the same structures are also designed to other methods such as those used in New Zealand and Greece. The resulting different designs are then assessed by subjecting the structures to a suite of strong ground motions, carrying out inelastic time history analysis, and comparing the results against design action effects. It is found that although modern code procedures generally lead to satisfactory performance (differences among them do exist), the design of walls seems to be less appropriate in the case of unequal length walls. For this case a modified procedure is proposed, consisting of an additional factor to account for the relative contribution of walls of the same length to the total base and an improved envelope of wall shears along the height; this improved method seems to work better than the other procedures evaluated herein, but further calibration is clearly required.     

The numerical solution of the Advection-Dispersion Equation: A review of some basic principles

The simulation of solute transport in rivers is frequently based on numerical models of the Advection-Dispersion Equation. The construction of reliable computational schemes, however, is not necessarily easy. The paper reviews some of the most important issues in this regard, taking the finite volume method as the basis of the simulation, and compares the performance of several types of scheme for a simple case of the transport of a patch of solute along a uniform river. The results illustrate some typical (and well known) deficiencies of explicit schemes and compare the contrasting performance of implicit and semi-Lagrangian versions of the same schemes. It is concluded that the latter have several benefits over the other types of scheme.     

Towards error‐free hybrid simulation using mixed variables

Two procedures are developed and implemented in a hybrid simulation system (HSS) with the aim of enhancing the accuracy and reliability of the online, i.e. pseudo‐dynamic, test results. The first procedure aims at correcting the experimental systematic error in executing the displacement command signal. The error is calculated as the difference between command and feedback signals and correlated to the actuator velocity using the least‐squares method. A feed‐forward error compensation scheme is devised leading to a more accurate execution of the test. The second procedure employs mixed variables with mode switching between displacement and force controls. The newly derived force control algorithm is evaluated using a parametric study to assess its stability and accuracy. The implementation of the mixed variables procedure is designed to adopt force control for high stiffness states of the structural response and displacement control otherwise, where the resolution of the involved instruments may favour this type of mixed control. A simple pseudo‐dynamic experiment of steel cantilever members is used to validate the HSS. Moreover, two experiments as application examples for the two developed procedures are presented. The two experiments focus on the seismic response of (a) timber shear walls and (b) reinforced concrete frames with and without unreinforced masonry infill wall. Copyright © 2007 John Wiley & Sons, Ltd.