Study on strip buckling in continuous annealing lines/hot galvanizing

In continuous annealing lines/hot galvanizing,strips are guided by upper and lower rolls in an alternate up and down vertical motion.This kind of process consisting of heating,soaking,and cooling furnaces(or zones) has several advantages in terms of productivity and product quality.Main problems encountered in continuous annealing lines are misguiding and formation of buckling.The strip buckling causes the strip to be rejected and,in the worst case,the strip breaks and the continuous annealing lines are compelled to stop.In this paper the elastic-plastic model of the strip traveling and the corresponding boundary condition were constructed dependant on the theory of mechanic.Simulations are performed in two steps.First,a homogeneous longitudinal tensile stress is applied at one end of the strip,the other end of the strip and the roll are restricted.In the second step,the applied tension remains constant.A uniform displacement is applied to the other end of the strip and a rotation to the roll. The transverse compressive stress,the buckling formation during strip traveling process,the location for the buckling taking place and the buckling criterion were investigated systematically.The result shows that the transverse compressive stress increases with the increase of the tensile stress and the crown of the tapered roll. Because the contact area between the tapered roll and the strip increase with the decrease of the crown,the tensile stress distribution is more homogeneous in the transverse direction of the strip.An additional transverse compressive stress is created and a buckling is also observed due to the friction during the strip motion in the second step.Once the buckling is appearance,it is very hard to be removed only through decreasing the applied longitudinal tension,because the strip wrinkle still keeps high level due to the effect of the buckled strip,the wrinkle would evolve into buckling eventually.The buckling formation process predicted by the finite element model is very similar to those observed in industrial processing lines.It takes place on the cylindrical part of the tapped roll and the buckling is moving to the middle part of the tapped roll with the increase of the crown,its width is about 2-4 mm.The criterion for the buckle occurrence is also discussed,in the prescribed situation,the transverse shell curvature increases with the strip displacement,if the transverse shell curvature reaches 0.1 mm^(-1), the buckling would take place.

Driving control technology for a continuous annealing line

This paper introduces AC variable-speed driving control technology application in the continuous annealing line,including the drive system configuration,the driving control characteristics of CAL and the main control functions of the drive system.Firstly introduces the main process of the continuous annealing line,the features of the 6SE70 series common DC bus drive system and the G150 series drive system. Secondly,for the continuous annealing line,there are more strict requirements for the continuity of production and more special requirements for the drive control characteristics.We do a lot of improvement and standardization for the driving control functions and the interfaces of the line automation control system. This paper discusses the communication interface specifications and the dimension transformation methods between the drive and the basic automation system.The detail dimension transformation methods and calculation method about the line speed setting and the actual roller dimension setting are given,and detail description for the calculation method of the reference speed in the drive.Article also emphasized illustrates realizing and testing methods of inertia compensation of equipment in the drives,and standardize the value of line accelerate and decelerate rate,and the inertia test method and inertia compensation coefficient calculation method is introduced in this paper.For the bridge rollers and furnace help rollers load balance control,this paper presents two different load balance control strategies,the load balance control principle for bridge rollers which data communicates from main station to slave stations by Simolink,and the load balance control principle for furnace help rollers which use droop control.The different characteristics of those two methods are stated in detail.

Study and Application of a New On-Line Titration Technique

A new on line titration method and device based on a new technique continuous flow titration is described. By the means of electronically controlled switching of a solenoid valve, the main component of the system, the equivalent point of the titration is easily determined. Several kinds of mixing tools were examined, whereby a self made mixing chamber with minimum volume gave best results and was therefore used in the device. The error of the titration is within 0.2% and the relative standard deviation (RSD) is below 1.2%. The results show no difference compared with a commercial device, meanwhile the new on line titration system is cheaper and fully automated and thus easy to hand and less solvent consumption.

Who Is at Fault When It Comes to E-commerce Information Leaks?

According to data from the China E-commerce Complaint and Rights Safeguard Public Service Platform,information leaks are no more in the top 10 complaint issues,showing that e-commerce companies have made improvements to the protection of user information.However,as online purchasing further develops,how to prevent user information leaks and stealing of account information is

基于连续波SAR成像模型的输电线路悬垂绝缘子风偏角识别方法

为了在恶劣环境中保证输电线路悬垂绝缘子风偏角识别结果可信,提出基于连续波合成孔径雷达(SAR)成像模型的输电线路悬垂绝缘子风偏角识别方法。基于连续波SAR成像模型,持续发射脉冲信号,通过基于位置标定的绝缘子风偏角识别方法,定位绝缘子目标区域中绝缘子串2个端点的像素坐标,生成绝缘子SAR图像。采用基于改进频率变标算法的连续波SAR成像处理方法,缓解绝缘子SAR图像失焦现象,进行SAR图像分割,获取生成绝缘子SAR图像中绝缘子目标区域,并结合“两点确定一条直线”标准识别绝缘子串的风偏角。实验验证:所提方法在恶劣环境中像素拟合效果较佳,对绝缘子风偏角识别结果和实际风偏角的风偏度信息高度匹配。

DInSAR监测地表三维形变的方法

本文介绍了几种利用DInSAR技术监测地表三维形变的方法,并深入分析了它们各自的优缺点,对它们的使用条件和使用中的应注意的事项进行了讨论。对于DInSAR监测地表三维形变方法的选择,应取决于数据条件,地质情况以及精度等几个因素。文章的最后展望了DInSAR监测地表三维形变方法的发展趋势。

A Bridge Across the Oceans——An Interview with the Beijing CPAA Cultural Entertainment Company

AWRITER once comparedSino-foreign cultural ex- changes to a lengthybridge across the oceans of theworld.The Beijing CPAA Cultur- al Entertainment Company,esta- blished in the spring of this year,undoubtedly comes to many peo- ple’s minds when contemplatingthis remark.The Beijing CPAA Cultural En- tertainment Company is a subsidi- ary of the China Performing ArtsAgency,directly under the Ministryof Culture.It is a self-managed statefirm specializing in international ex-

New Structural Elements in Tellian Foreland Domain of the Northeastern Tunisia(Mateur Plain)after Integrating Geological and Geophysical Data

The following paper presents an integrated geological (field observations, wells data) and geophysical data (Gravity measurements and seismic profiles) in Tellian foreland domain of the northeastern Tunisia (Mateur plain) served for a new proposed structural map with many faults already recognized or supposed by traditional structural studies and highlights major regional accidents.

关于《On right continuity of a family of two-parameter σ-fields》一文若干问题的探讨

探讨《Ｏｎｒｉｇｈｔｃｏｎｔｉｎｕｉｔｙｏｆａｆａｍｉｌｙｏｆｔｗｏ－ｐａｒａｍｅｔｅｒσ－ｆｉｅｌｄｓ》（刊登在杂志ＳｔｏｃｈａｓｔｉｃＰｒｏｃｅｓｓｅｓａｎｄｔｈｅｉｒＡｐｐｌｉｃａｔｉｏｎｓ，１９９７，６６：１０７～１１３）所讨论的问题，指出该文主要命题的证明推导过程存在实质性错误．

基于人工智能的自动肺部超声评分对ARDS患者血管外肺水评估的价值

目的 评价基于人工智能(artificial intelligence, AI)的自动肺部超声评分(lung ultrasound score, LUS)对急性呼吸窘迫综合征(ARDS)患者血管外肺水(extravascular hung water, EVLW)评估的价值。方法 选择2019年1月至2022年6月上海长征医院急诊重症监护病房(EICU)符合ARDS诊断标准的28例患者作为研究对象,采用两种肺部超声评分方法:(1)基于两阶段级联深度学习模型评估ARDS的自动LUS(自动组LUS);(2)临床医生评估的LUS(人工组LUS),并采用脉波指示剂连续心排血量监测技术(PiCCO)监测血管外肺水指数(EVLWI),年龄18~80岁,性别不限,在行PiCCO检测前0.5 h内行肺部超声检查,计算LUS,并行动脉血气分析,记录氧合指数(PaO2/FiO2),比较两种LUS方法在不同严重程度ARDS患者诊断中的作用。结果 自动组LUS和人工组LUS与EVLWI高度相关(R^(2)=0.924 vs.R^(2)=0.910),在评估EVLW方面均显示出较高的准确性,LUS的受试者工作特征(ROC)曲线分析以PiCCO计算所得:(1)以EVLWI>7 mL/kg为界,对自动组和人工组LUS方法绘制ROC曲线,两组ROC曲线下面积(AUC)分别为0.956和0.947,两组方法的敏感度分别为90.8%和87.0%,特异度分别为94.3%和92.5%。(2)以EVLWI≥10 mL/kg为界,对自动组和人工组LUS方法绘制ROC曲线,两组ROC曲线AUC分别为0.979和0.978,两组方法的敏感度分别为92.2%和89.1%,特异度分别为97.9%和96.7%。(3)以EVLWI≥15 mL/kg为界,对自动组和人工组LUS方法绘制ROC曲线,两组ROC曲线AUC分别为0.997和0.996,两组方法的敏感度分别为94.5%和93.0%,特异度分别为98.8%和97.8%。结论 人工智能自动LUS可用于临床ARDS的诊断及严重程度的评估。

基于主线不停运的城轨支线独立运营改造方案

研究目的:针对大型铁路枢纽接入已运营轨道交通线路引起的既有线改造问题,为满足铁路枢纽与轨道交通连接线(支线)施工期间主线正常运营不受影响,对改造涉及的运营组织与接轨方案进行系统研究,并对土建、轨道、接触网、环网与动照、信号、综合监控与通信系统等的改造及影响进行深入研究,在统筹考虑实施难度、投资与工期的基础上,提出实施风险最小、技术最合理的改造方案。研究结论:(1)既有高架车站与区间改造影响范围较小且相对可控,可以实现主线正常运营情况下新建独立运营支线工程;(2)为最大程度保障主线运营不受影响,在现有技术水平条件下,应尽量避免在运营天窗期进行各类信号光电缆的割接;(3)支线独立运营方案,应尽量采取措施将新建支线与主线相连、轨道相通,以利于车辆检修与维保,并增加运营的灵活性;(4)桥梁浇筑与平移施工临近既有线,实施阶段应进一步完善工艺衔接与交叉施工统筹,增加既有线安全保障;(5)本研究结论可为类似工程提供参考。

桥梁预拱度对行车舒适性的影响及桥面线形调整

为研究成桥预拱度对连续刚构桥行车舒适性的影响,以多座主跨跨径为110~200 m的连续刚构桥为研究对象,首先,采用滤波白噪声法建立桥面时域模型,并与按余弦曲线设置的成桥线形叠加模拟成桥后的桥面不平度;其次,采用MATLAB/Simlink搭建车辆-桥面系统模型,以加速度均方根值(RMS)作为桥梁边跨、中跨桥面的行车舒适性评价指标,以最大瞬态振动值(MTVV)作为边跨峰值处短时内的行车舒适性评价指标;最后,分析采取经验法按照余弦曲线设置成桥预拱度的桥梁其跨径和设计时速对边、中跨RMS值的影响,以及成桥预拱度取值对边跨3L/8处MTVV值的影响。研究结果表明:在边跨、中跨处RMS值均小于0.315 m/s^(2),说明采取经验法按照余弦曲线设置成桥预拱度并不影响中跨处的行车舒适性;在边跨3L/8处MTVV值在短时内存在大于0.345 m/s^(2)的情况,说明在边跨峰值处短时内会产生一定不舒适感。提出了一种基于桥面铺装层施工优化边跨3L/8处和边墩墩顶桥面线形的方法,改善了边跨的行车舒适性。

大型连续绿茶精制加工生产线研发

茶叶加工技术与装备是茶叶产业发展的基础,对行业发展起着举足轻重的作用。为实现绿茶加工机械自动化生产,设计了大型连续绿茶精制加工生产线,阐述了该生产线系统结构、主要生产环节及安装调试应用。基于PLC控制的大型连续绿茶精制加工生产线,主要由鲜叶上料输送机、大型滚筒杀青机、冷却回潮机、四机协同联动式揉捻机组、并列连续预烘干机组、储料仓、计量分料装置、茶叶炒干与抛光机组、筛分装置、风选装置及配套的测控系统等组成。针对绿茶加工工艺的各个环节,采用模块化设计,根据茶叶加工企业的厂房实际情况,灵活安装组线,满足企业个性化需求。基于模糊PID温度控制的大型滚筒杀青机双模糊控制技术,解决了传统杀青温度与时间无法实现精确控制的难点问题。采用链式刮板输送智能加料装置与多机联动协同连续揉捻控制技术,实现多机协同联动式自动加料连续揉捻,边进料边揉捻,揉捻均匀度高。生产线上杀青机、理条机和烘干机各环节温度采用模糊PID控制,解决了茶叶加工温度、投叶量与杀青、理条、烘干时间实时配合的问题,输入不同等级、不同重量的鲜叶可输出相适应的杀青温度和时间,实现对茶叶生产过程的精确控制,减少人为因素的干扰,实现绿茶的智能化生产。近年来,生产线用户遍布皖、苏、浙、云、贵、川、豫、湘、鄂和陕等10多个省份200余家茶叶生产企业。该生产线的推广应用,实现了茶叶规模化生产,保证了茶叶品质,对茶产业发展具有重要意义。

基于差分分段PCA的多模态过程故障监测

多模态的故障监测是一个复杂的问题,既需要考虑稳定模态下的故障监测,也需要考虑不同模态间的过渡故障监测.不同稳定模态下的数据具有不同的相关关系,对每个稳定模态需要建立不同的稳定模态模型.当稳定生产模态发生改变时,生产过程进入过渡模态,需要考虑过渡变量相关关系的变化.本文通过对过渡数据差分,得到变量相对变化信息.利用主成分分析(Principal component analysis,PCA)分段对差分变量的相关特性进行分析,提取相对变化的特征.最后以实际连续退火机组生产线为背景,用基于差分分段PCA的多模态方法对多模态过程进行故障监测,发现算法很好地反映了实际过渡过程机理,验证了算法的有效性.

基于主应力轨迹线的连续碳纤维复合材料3D打印路径规划方法

连续碳纤维复合材料3D打印成型零件的力学性能对纤维的铺设方向有需求,传统的路径规划方法基于零件的形状轮廓进行填充,不能满足零件的实际使用性能。针对这一问题,提出基于主应力轨迹线的连续碳纤维复合材料3D打印路径规划方法。基于连续碳纤维复合材料三维模型的有限元分析数据,通过材料力学计算得到相应的主应力轨迹线;通过连续碳纤维复合材料3D打印的打印参数对得到的主应力轨迹线进行调控,保证每一条轨迹线之间的间距契合3D打印要求;通过坐标变换调整有限元分析坐标系以及打印机坐标系;通过以上调控生成用于连续碳纤维复合材料3D打印的G code规划文件。通过路径规划仿真对比和打印拉伸实验,基于主应力轨迹线生成的连续碳纤维复合材料3D打印路径比传统直线碳纤维复合材料3D打印路径性能提高了4.5%,验证了基于主应力轨迹线的连续碳纤维复合材料3D打印路径规划方法的有效性。

WSN中LEACH协议簇头生成算法的改进

近年来随着无线传感网络技术的发展,分簇路由协议得到了较为深入的研究。其中针对如何延长传感器网络的生存周期,降低传感节点的能耗成为研究的重点。本文分析了LEACH协议中簇头生成算法并提出了改进机制,并对它们的性能做了比较,为寻求和设计更为高效的簇头生产算法奠定了基础。

LDA与LSD相结合的车道线分类检测算法

提出一种车道线分类检测算法。首先采用LDA对道路图像进行有针对性的灰度化,以便更好地区分车道线与道路。采用LSD算法检测灰度图像中的直线部分并确定车道线的方向。在此基础上,选取符合车道线灰度范围内的像素点。对远距离的像素点采用抛物线拟合,近距离的像素点采用直线拟合。同时,将检测到的车道线进行虚线实线的分类标记。最后结合视频序列的连续性对检测结果进行反向验证。实验结果证明,提出的方法对直道弯道检测均有很好的效果。算法的处理速度为每秒10帧左右,采用的测试视频的帧率为每秒15帧,基本满足实时性的要求。

TiB_2/Al喷丸形变层连续加热组织结构

研究加热过程中TiB2/6351Al及其基体合金喷丸形变层组织结构的变化,利用X射线衍射线形分析方法计算不同加热温度和时间下的晶块尺寸和显微畸变。结果表明:喷丸使表层晶粒细化,织构消失并且在加热后不再出现;加热过程中,复合材料晶块长大速度低于基体材料,且复合材料显微畸变更易释放;喷丸过程中增强体周围产生的高密度位错使储存能提高,从而促进再结晶,但晶块的进一步长大因增强体的钉扎作用而受到阻碍;复合材料的热稳定性高于基体合金。

大吨位连续梁上跨既有铁路转体施工技术研究

为解决既有铁路线上跨新建大吨位连续梁上转体施工难题,以京滨铁路JBSG–3标段连续梁为例,对上跨既有铁路线(大北环铁路)的转体施工难点及要点进行总结,该大北环铁路两侧转体桥梁重达7 700 t,并与大北环铁路相交交角为54°11',由于转体桥梁自重大及大北环铁路线繁忙、天窗时间短,现场转体施工难度极大。拟定采取水平转体法+球铰系统进行桥梁转体施工,通过现场严格控制球铰安装精度、梁体准确称重及配重、试转优化、转角刻度及梁面轴线对转体位置双控等多重措施并行,最终在48 min内安全、可靠、精准地完成既有铁路线两侧梁段的转体施工。

集值拟单调算子的Browder-Hartman-Stampacchia变分不等式

在本文中,作者引入了集值拟单调和强拟单调算子概念,对沿线节上半连续的集值拟单调和强拟单调算子和对沿线节下半连续的集值强拟单调算子证明了 Browder-Hartman-Stampacchia 型变分不等式解的某些存在性定理,这些定理分别改进和推广了 Browder,Bae-Kim-Tan,丁,Hartman-Stampac-chia,Shih-Tan 和 Tan 等人的最近结果.