A Control System Design for Welding Oscillator Based on STC Single Chip

介绍了基于STC单片机焊接摆动器控制系统的设计,包括电源模块、单片机控制模块、直流电机脉宽调制(PWM)调速模块、红外线二极管检测与放大电路模块、人机交互模块等系统硬件设计,以及用C语言实现的系统软件设计.该系统能够控制焊枪以特定的预置参数进行摆动并配合一台小车进行流水线操作,从而达到自动焊接过程中的特殊要求.通过现场运行,系统稳定,可靠性高,满足工业现场要求.This paper introduces a design of control system of welding oscillator on the basis of STC single chip.It does not only include system hardware design consisting of power module,single-chip control module,module of DC motor speed regulation system of Pulse Width Modulation(PWM),module of infrared diode detection and amplifier circuit,and module of human-computer interaction,but also software design achieved by C.The system is able to control the welding torch that swings with the specific preset parameters and operates with a trolley on the pipeline in order to achieve the special requirements of the automatic welding process.Through on-site operation,the system is stable,high reliable and meets the demands of industrial field

Identification and analysis of odor of patients with exterior syndrome based on medical electronic nose

目的:运用自主研发的医用电子鼻探讨表证患者口腔呼气的气味图谱特征及气味识别准确率。方法:选择表证青年患者150例和健康青年人200名,运用基于薄膜型气体传感器阵列技术的医用电子鼻(nAnOfIlM-EnOSE MEdICAl001)采集口腔呼气的气味图谱,以响应曲线的振幅和上升斜率作为曲线特征,分析表证患者及其寒热病性的图谱特征,并进行判别分析。结果:表寒证和表热证患者的气味图谱响应曲线A、b、d、E、g、H的振幅和上升斜率均显著高于健康学生(P<0.01)。表热证患者的气味图谱响应曲线A、b、d、E、H的振幅和上升斜率均显著高于表寒证患者(P<0.05,P<0.01),表热证患者的气味图谱响应曲线g的振幅显著高于表寒证患者(P<0.01)。判别分析显示对健康青年人、表寒证青年患者、表热证青年患者口腔呼气的识别准确率分别为90.5%、86.5%、88.0%,对全部案例的识别准确率为89.1%。结论:表证青年患者口腔呼气的气味较健康青年人浓烈,且表热证青年患者气味变化较表寒证青年患者更明显,本医用电子鼻能够较为敏感和准确地辨识表证青年患者口腔呼气的气味特征及其寒热病性。医用电子鼻技术的发展可为中医嗅诊客观化研究提供手段和方法。Objective: to explore the odor response pattern characteristics of oral breath of patients with exterior syndrome and accuracy rates of odor identiication by medical electronic nose which was independent research and development.Methods: 150 young patients with exterior syndrome and 200 healthy young students were observed.Odor response patterns of oral breath were collected by the electronic nose(Nanoilm-Enose Medical001) based on a ilm of gas sensor array.The amplitude and rising slope of response curves were selected as curve characteristics to analyze pattern characteristics of exterior syndrome including exterior cold syndrome and exterior heat syndrome,and discriminant analysis was done.Results: In odor response patterns of patients with exterior cold syndrome and with exterior heat syndrome,the amplitudes and rising slopes of response curve A,B,D,E,G and H were signiicantly higher than those of healthy students(P<0.01).In odor response patterns of patients with exterior heat syndrome,the amplitudes and rising slopes of response curve A,B,D,E and H were signiicantly higher than those of patients with exterior cold syndrome(P<0.05,P<0.01),and the amplitude of response curve G was signiicantly higher than that of patients with exterior cold syndrome(P<0.01).Discriminant analysis showed that the accuracy rate of oral breath identiication of healthy students,patients with exterior cold syndrome and patients with exterior heat syndrome was 90.5%,86.5% and 88.0% respectively,and the accuracy rate of all cases was 89.1%.Conclusion: The odors of oral breath of patients with exterior syndrome were signiicantly stronger than those of healthy people.The odors of patients with exterior heat syndrome were signiicantly stronger than those of patients with exterior cold syndrome.This medical electronic nose could distinguish odor characteristic of oral breath of patients with exterior syndrome sensitively and accurately;and it could also distinguish odor characteristic of exterior cold syndrome from exterior heat syndrome.The development of medical electronic nose could provide a kind of new means for the study on the objectiication of TCM smelling examination.国家自然科学基金项目(No.30901899); 福建省教育厅A类项目(No.JA09132)~

电袋复合式除尘器内部流场的数值模拟

电袋复合式除尘器对于细颗粒物具有很好的脱除效率,是目前除尘技术重要的研究方向,但电场和布袋之间合理的结构设计一直是研究热点。为了得到均匀的内部流场、降低系统的运行阻力和增加滤袋的使用寿命,采用CFD方法对三种不同的电袋结合形式下的除尘器内部气相流场进行模拟,滤袋设置为多孔阶跃边界进行描述气体通过滤袋的行为。模拟结果表明:添加导流片数量为4个时的流场分布比无导流片时更均匀,当导流片数量为6个时,气流分布均匀性反而最差;随着导流片个数的增加,系统整体压力损失逐渐增大,但滤袋区的压力损失在导流片数量为4时最小,这是因为其流场分布最均匀;前排布袋流量分配较大,在顶端出口处存在高速区,是滤袋容易损坏的区域。</p

贵金属催化剂对VOCs催化氧化的研究进展

催化氧化法是目前最有效的处理VOCs 的方法之一。就贵金属催化剂在VOCs 的催化氧化中的应用,列举了近年来Pd、Pt、Au、Ru 催化氧化的实例,并对其反应机理进行了总结。最后,归纳并重点分析了催化剂的分散度、颗粒粒径、载体3个因素对催化活性的影响。同时,对预处理也作了一定的阐述

贵金属催化剂对VOCs催化氧化的研究进展

催化氧化法是目前最有效的处理VOCs 的方法之一。就贵金属催化剂在VOCs 的催化氧化中的应用,列举了近年来Pd、Pt、Au、Ru 催化氧化的实例,并对其反应机理进行了总结。最后,归纳并重点分析了催化剂的分散度、颗粒粒径、载体3个因素对催化活性的影响。同时,对预处理也作了一定的阐述

贵金属催化剂对VOCs 催化氧化的研究进展

催化氧化法是目前最有效的处理VOCs 的方法之一。就贵金属催化剂在VOCs 的催化氧化中的应用,列举了近年来Pd、Pt、Au、Ru 催化氧化的实例,并对其反应机理进行了总结。最后,归纳并重点分析了催化剂的分散度、颗粒粒径、载体3个因素对催化活性的影响。同时,对预处理也作了一定的阐述

含铜PVD硬质涂层的结构及其性能研究现状

表面摩擦和磨损是机械零部件失效和损伤的主要形式,影响和决定着材料的使用寿命。传统降低材料磨损的主要措施是采用液体润滑油,但在高温、真空和海水等环境下,润滑油脂无法充分发挥作用,PVD硬质耐磨减磨涂层成为减磨润滑材料发展的新成果,目前已得到广泛的研究和开发。在海洋工业领域,淤泥、海藻和细菌等海洋生物附着于舰船和海工装备表面,降低了船舶的抗摩擦性能和设备稳定性,影响船舶航行速度,增加船舶的燃料消耗,严重威胁着海洋航行安全。硬质防污涂层可以很好地应用于海洋装备零部件的保护。综述了将软质金属Cu引入物理气相沉积的硬质涂层,来拓展硬质涂层的功能,实现硬质涂层自润滑耐磨及抗菌防污性能的研究现状。重点介绍了Cu的引入对PVD硬质涂层结构、硬度、摩擦学行为和抗菌性能的影响,探讨了硬质涂层中Cu的减摩机理,阐明了Cu的抗菌机制,展望了含Cu物理气相沉积硬质涂层未来的发展方向和应用前景

Evaporation Process of Sessile Liquid Droplet and Layer in Steady State

The ethanol liquid droplet with constant contour and liquid layer with constant height in steady-state contained in the heated substrate under evaporation have been experimentally investigated utilizing infrared thermography and volume control technique. The heat and mass transfer and thermal flow patterns at the gas-liquid interface during droplet and layer evaporation are analyzed through their heat flux curves and interface temperature fields. Experimental results reveal that the steady-state evaporation of liquid droplet and layer at surface emerges after the evaporation rate is equal to replenishment rate by continuous liquid refilling and temperature filed becomes uniform. For evaporating droplets, there are two main stages during the evaporation evolution: unstable evaporation with decreasing heat flux and steady evaporation with constant heat flux. In the steady stage, the interface temperature gradually becomes uniform, and convection cells at the interface disappear. For evaporating layer, three main stages are present: first, the formation and splitting of Marangoni convection cells, then the hydrothermal wave propagating from "source" to "sink", and finally the stable flow stage without vortex cells. The results also show that the direction of the temperature gradient at evaporating droplet interface is opposite under different substrate materials (Aluminum and PTFE). The heat flux density of the evaporating droplet on Aluminum substrate is larger than that on PTFE, resulting in a higher evaporation rate. These new findings help to gain a better understanding of the coupling mechanism between phase change and thermal convection inside evaporating liquid droplets and layers

多弧离子镀制备TiSiN-Cu涂层的结构和摩擦学性能

目的通过在TiSiN涂层中掺杂软金属Cu,提高TiSiN涂层的摩擦性能。方法采用多弧离子镀技术,在316L不锈钢基体上沉积TiSiN-Cu涂层。用扫描电子显微镜(SEM)观察涂层的表面形貌,用X射线光电子能谱仪(XPS)和X射线衍射仪(XRD)来分析涂层的元素组成和相组成,通过纳米压痕硬度测试和摩擦磨损实验,表征不同Cu含量TiSiN-Cu涂层的力学性能和摩擦学性能。结果 Cu含量对TiSiN涂层的结构、硬度和摩擦性能有明显影响。Cu在涂层中主要以单质形式存在,由于与空气接触,涂层表面有少量的CuO。随着Cu含量的增加,TiN的晶粒尺寸先减小后增加,硬度先升高后降低。在Cu原子数分数为6.28%时,硬度达到最大值29.26 GPa。在干摩擦条件下,TiSiN-Cu涂层的磨损率在Cu原子数分数为12.93%时达到最低,为6.65×10-7 mm~3/(N·m)。在海水环境下,涂层的磨损率较大。结论软金属Cu作为固体润滑颗粒可以明显改善Ti Si N涂层的干摩擦性能,在海水条件下,摩擦与腐蚀的交互作用加速了涂层材料的损耗