壁厚补偿原理在R/D<2弯管制作工艺中的应用

介绍了壁厚补偿原理在R/D值较小情况下弯管制作中的应用。该方法克服了常规工艺在此情况下容易出现的问题 ,使弯管加工的各项指标均优于国家标准     

Three‐dimensional numerical simulation of coalescence and interactions of multiple horizontal bubbles rising in shear‐thinning fluids

The dynamics of multiple horizontal bubbles rising from different orifice arrangements in shear‐thinning fluids was simulated numerically by three‐dimensional Volume of Fluid method. The effects of bubble size, rheological properties of shear‐thinning fluids, and orifice structure arrangements on multiple bubbles interaction and coalescence were analyzed, and the mechanisms of bubble coalescence and breakup were fully discussed and elucidated. The variation of bubble rising velocity during coalescence process and freely rising processes for different orifice arrangements was also deeply investigated. The critical initial horizontal intervals for coalescence of multiple horizontal bubbles with various orifice arrangements were attained by simulation, which could serve as the critical criterion of bubble coalescence or noncoalescence. Furthermore, the critical bubble interval was predicted based on the film drainage model, the prediction accords well with the simulation result and is quite conducive for the design and optimization of perforated gas–liquid contact equipment. © 2015 American Institute of Chemical Engineers AIChE J, 61: 3528–3546, 2015     

Zero‐Modified Geometric INAR(1) Process for Modelling Count Time Series with Deflation or Inflation of Zeros

In this article, we propose a first‐order integer‐valued autoregressive [INAR(1)] process for dealing with count time series with deflation or inflation of zeros. The proposed process has zero‐modified geometric marginals and contains the geometric INAR(1) process as a particular case. The proposed model is also capable of capturing underdispersion and overdispersion, which sometimes are caused by deflation or inflation of zeros. We explore several statistical and mathematical properties of the process, discuss point estimation of the parameters and find the asymptotic distribution of the proposed estimators. We also propose a test based on our model for checking if the count time series considered is deflated or inflated of zeros. Two empirical illustrations are presented in order to show the potential for practice of our zero‐modified geometric INAR(1) process. This article contains a Supporting Information.     

油管缺陷在线检测仪的研究

文中研究了油管局部缺陷和壁厚减薄缺陷的漏磁场检测原理。研制了一种新型的井口式油管缺陷检测仪,缺陷检测传感器的组合式探头具有自动张合、浮动和随动功能,能够满足油管在线检测对检测传感器的要求。仪器可用在井口对油管进行在线连续定量检测,检测结果不受管表面的油泥或其它非导磁性材料的影响。测试表明,该仪器具有精度和分辨率高,结构简单,安装方便,性能可靠等优点。     

再论“天人合一”与中国传统建筑

“天人合一”观是中国传统哲学中最具根源性的一个观念，其在思想史上有一个发展演变过程。“天人合一”观念对中国传统建筑影响很大。通过对中国传统建筑基本单元问题的分析及中国人环境心态的形成原因的探讨，同时通过论述中国古代工匠的地位，提出中国传统建筑始终逃避在自然之外，“天”与“人”并没有达到“合一”的观点。     

某中学教学楼基础设计

通过对某中学教学楼的基础设计,探讨如何在陡坡上利用深、浅基础相结合的方式设计纵长建筑物的基础。     

INFLUENCE OF MATERIAL REMOVAL ON THE DYNAMIC BEHAVIOR OF THIN-WALLED STRUCTURES IN PERIPHERAL MILLING

Machining is a material removal process that alters the dynamic properties during machining operations. The peripheral milling of a thin-walled structure generates vibration of the workpiece and this influences the quality of the machined surface. A reduction of tool life and spindle life can also be experienced when machining is subjected to vibration. In this paper, the linearized stability lobes theory allows us to determine critical and optimal cutting conditions for which vibration is not apparent in the milling of thin-walled workpieces. The evolution of the mechanical parameters of the cutting tool, machine tool and workpiece during the milling operation are not taken into account. The critical and optimal cutting conditions depend on dynamic properties of the workpiece. It is illustrated how the stability lobes theory is used to evaluate the variation of the dynamic properties of the thin-walled workpiece. We use both modal measurement and finite element method to establish a 3D representation of stability lobes. The 3D representation allows us to identify spindle speed values at which the variation of spindle speed is initiated to improve the surface finish of the workpiece.     

长城并非线性——卫所制度下明长城军事聚落的层次体系研究

长城防御仅靠长城墙体及其上的墩台,并不能阻挡住北方游牧民族的铁骑,其强大的防御能力有赖于长城沿线驻扎的上千个屯兵城,即军事聚落,这些军事聚落分布在八千多公里的明长城沿线,是长城防御体系的重要组成部分。卫所制度下军事聚落分为镇城、路城、卫城、所城和堡城五个层次,各层次军事聚落又具有相应的建筑特点。     

水泥土复合式支挡结构探讨

探讨用于基坑支挡的水泥土复合式结构的应用，即对其设计计算方法和设计理论中的一些相关问题提出自己的看法。     

多自由度墙体喷涂机器人机构设计

房屋装修过程中墙体涂料的喷涂主要由人工粉刷完成,劳动强度大,工作环境恶劣,喷涂机器人能够代替人在房屋装修过程中进行建筑墙面自动喷涂各种涂料。整个机构采用5个自由度的开放关节型机械臂完成,移动小车作为基座并完成机构的整体水平移动,腰部关节、大臂、小臂及粉刷头在运动控制卡及步进电机的控制下,使,得粉刷头始终紧贴墙壁做上下往复运动完成粉刷动作,并获得持续的涂料供给。