A framework of virtual prototyping environment for the design and analysis of mechanical mechanism with clearance

Mechanical mechanisms with clearance abound in technological fields such as robotics, machine and steam turbine industry. The dynamic performance of these mechanisms in working condition can be achieved provided that the effects of the different on the mechanisms (such as mechanism dynamics, technological effects and thermal behaviour) are thoroughly understood. Virtual prototyping provides an integration of multi-domain dynamic simulation for the design and analysis process. In the current paper, a framework of virtual prototyping environment for the design and analysis of mechanical mechanism with clearance is presented. A case study with such a simulation strategy is studied for the optimum design and analysis of the technological parameter.     

钻孔灌注桩施工中常见质量事故的控制和防治

介绍了钻孔灌注桩成孔质量的影响因素 ,详细叙述了钢筋笼的制作和吊放处理步骤 ,阐述了断桩发生的原因 ,提出了具体的防治措施 ,经实践效果良好     

略论中国传统合院住宅形式的固化与沿用

合院式住宅是中国人沿用了二千多年的典型形制，除了其能满足采光、通风的要求和建造相对简化外，中国传统社会早期的中霤祭祀和以五行为基本元素的统括万物的宇宙模式对于中国式合院住宅的固化与沿用，也起了不可忽视的作用。     

Control of discrete time nonlinear systems with a time-varying structure

In this paper, we present a control methodology for a class of discrete time nonlinear systems that depend on a possibly exogenous scheduling variable. This class of systems consists of an interpolation of nonlinear dynamic equations in strict feedback form, and it may represent systems with a time-varying nonlinear structure. Moreover, this class of systems is able to represent some cases of gain scheduling control, Takagi-Sugeno fuzzy systems, as well as input-output realizations of nonlinear systems which are approximated via localized linearizations. We present two control theorems, one using what we call a “global” approach (akin to traditional backstepping), and a “local” approach, our main result, where backstepping is again used but the control law is an interpolation of local control terms. An aircraft wing rock regulation problem with varying angle of attack is used to illustrate and compare the two approaches.     

变频器在暖通空调行业中的应用

本文提出中央空调系统的一种变频调速改造方案，介绍了该系统的结构组成及运行原理，对系统各部分的作用进行了讨论。     

数字电位器的应用技术

从应用的角度出发，介绍合理设计应用电路和合理选择数字电位器的种类与型号，来克服数字电位器普遍存在的主要缺点的方法。文章具有较强的针对性和可操作性，对数字电位器的应用实践具有指导作用。     

简析Ⅲ类PHC管桩的成因及加固补强处理方法

本文主要通过Ⅲ类PHC管桩的形成分析,经过各方论证采用了合适的处理方法,取得了较好的效果。     

对称配筋小偏心受压构件的截面设计

对小偏心受压构件在对称配筋情况下的截面配筋计算，提出用最佳一次逼近多项式简化基本公式，直接按二次方程求解ξ的近似方法，具有精度高，相对误差小，计算方便等优点，可供工程设计人员参考。     

Engaging the aging workforce: The relationship between perceived age similarity, satisfaction with coworkers, and employee engagement.

Business publications and the popular press have stressed the importance of creating conditions for meaningful employee expression in work roles, also known as engagement. Few empirical studies, however, have examined how individual or situational factors relate to engagement. Consequently, this study examines the interplay between employee age, perceived coworker age composition, and satisfaction with older (older than 55) and younger (younger than 40) coworkers on engagement using a sample of 901 individuals employed in the United Kingdom. Results indicated that satisfaction with one's coworkers related significantly to engagement. Moreover, perceived age similarity was associated with higher levels of engagement among older workers when they were highly satisfied with their coworkers over 55 and lower levels of engagement when they were not. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

道路边坡生态防护初探

随着我国经济实力的增强和人们环保意识的提高，国家已经十分重视道路建设中的生态建设和环境保护。通过对已建道路边坡防护方式进行分析，找出了存在的问题，提出改善和提高道路边坡防护的方法，并通过工程实例进一步得到验证。