UEA无缝施工新技术在煤气柜基础中的应用

结合具体工程实例，介绍了UEA无缝施工新技术在防治煤气柜基础环梁裂缝中的应用，经实践证明，此技术既方便可行，又能显著改善工程质量，并缩短工期。     

单镜头大视场拼接成像方法及实现

在远距离目标轨迹测量系统中,当前的长焦相机由于CCD尺寸限制一般视场角度较小,无法实现对目标的可靠捕获。在对比当前的几种大视场拼接成像方法后,针对远距离目标测量系统的要求提出了一种通过控制单个相机进行圆锥旋转来模拟4相机阵列实现大视场成像的方法。设计了实验样机对该方法进行验证。首先根据该成像方法设计了相机运动控制方案和相应的机械结构,然后设计了相机的触发控制以及图像数据的传输和处理流程,最后使用该样机进行了实验。实验中样机经校准后采集到了相对位置正确的子视场图像,并拼接获得了大视场图像。使用视场角度为1.02°的小视角相机,实现了4个有一定程度重合的子视场2×2拼接,最终获得了1.93°的大视角。该方法为远距离目标测量系统中的目标捕获子系统设计提供了新思路。     

钛合金无缝管热连轧温度场模拟

采用有限元法分析了钛合金无缝管多机架连轧下的温度状态。模拟结果表明：随轧制道次的增加,辊底下的外表面温度以逐渐减缓的速率降低,中心温度整体上以逐渐减缓的速率上升,而辊缝下外表面温度持续升高。中心温度的周向不均匀性在奇数道次时减小,在偶数道次时增大,而外表面温度分布的不均匀性与此相反。前一机架压下量与后机架辊缝处温升呈负相关,降低前一机架压下量可显著提升后机架周向温度不均匀性。温度测量和晶粒形貌分析的结果表明,模拟结果与实验结果吻合度较高。     

双轮廓仪金属增材制造工件表面3 维重建技术

为解决金属增材制造的零件易出现变形的问题,开展基于双轮廓仪的变形检测技术研究。以激光三角测 量法为测量核心方法,通过点云数据拼接处理,完成了工件表面形貌的3 维重建。实验验证结果表明：该系统能达 到的测量分辨率为2 μm,可为金属增材制造加工过程的变形检测技术提供一种新的检测手段。     

Review of research developments of 12Cr1MoVG heat resistant steel in China

In this paper,we review the evolution of 12CrlMoV steel standards at home and abroad,analyze the effects of various elements and determine their optimal contents in steel.The influence of heat treatment and microstructure on the creep strength of 12Cr1MoV steel is investigated.Statistical results from conventional mechanical properties,ductile-brittle transition temperature,high temperature oxidation resistance,aging,instant high temperature properties,and creep are introduced.The results show that the chemical composition and heat treatment process of 12CrlMoVG steel identified in the GB 5310-2008 standard is appropriate,resulting in a steel with higher creep strength and good comprehensive properties.     

大直径薄壁X60钢级管线用无缝钢管的开发

介绍了采用局部感应加热热扩工艺开发生产X60钢级Φ406.4 mm×7.92 mm管线用无缝钢管的工艺过程。通过检测成品的几何尺寸、机械性能以及金相组织分析,证明该产品尺寸符合标准要求,金相组织均匀,综合性能达到API Spec 5L标准PSL2水平。热扩成型的同时进行热处理,消除了钢管内应力,缩短了生产周期,降低了大直径薄壁高钢级管线用无缝钢管的生产成本。     

Test bed for characterization and predistortion of power amplifiers

A platform of high accuracy and reliability is crucial for power amplifier (PA) designers to assess the characteristics of the PA prototype, and for the digital predistorter engineers to validate their models and algorithms. Digital processing techniques for building a test bed of high performance for PA characterization and predistortion (PD) are discussed in this article. We also proposed a novel technique to characterize the frequency responses of the vector signal generator and vector signal analyzer independently without using any other instrument. The techniques described in this article are quite useful, especially for narrowband vector transmitters and receivers, to improve their performance. These techniques were experimentally evaluated, both for characterization and PD of a class‐F PA. Test results show that using such techniques can successfully build a test bed of high accuracy and wide bandwidth. © 2012 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2013.     

基于数据拼接的金刚石刀具刃口三维形貌表征技术

原子力显微镜(AFM)是获取金刚石刀具刃口纳米级三维形貌的重要手段,但其存在测量范围小,难以表征参与切削区域整段刃口形貌特征的问题。采用基于迭代最近点法的刃口AFM测量数据拼接算法,获得了由多组数据拼接得到的刃口纳米级三维形貌,并进行了切削实验验证。实验结果表明,采用的数据拼接方法可较好地用于表征刀具刃口三维形貌。