基于Micro830的异步电动机控制系统设计

为解决异步电动机的控制问题,本文利用Micro830PLC控制器和PowerFlex 4M变频器,构建了异步电动机控制系统,结合RsLinx和FactoryTalk View Studio软件,实现了上位机对整套电机控制系统的实时监控。同时利用RsLinx建立OPC通讯,并在FactoryTalk View Studio上利用已建立的OPC数据服务器进行上位机操作。经过对控制系统进行调试及运行,结果表明,监控软件可以实现电动机启动、停止、正反转的自由切换,响应速度快,能够实现有效地控制,整个控制系统稳定性和精确度较高,操作方便,上位机监控软件能实现转速和方向的实时显示和有效控制。该系统实现了异步电动机方向和转速的准确控制,具有良好的应用前景。     

基于VB的数据采集及反馈控制系统设计

在串口通讯的基础上利用VB6.0开发了数据采集及反馈控制系统,通过两个串口,计算机能够同时与锁相放大器和机械手控制电路进行通信。系统可以对数据进行采集并调用EXCEL表格自动记录,通过对采集到的数据进行分析,实时调整机械手指的动作,达到智能化反馈控制的效果。该设计经济可靠,系统运行稳定,可以满足实际项目使用的需要。     

低温传感器DT-470应用研究

Lake Shore公司生产的低温传感器以其高精度、高可靠性、高准确度的优良性能,广泛应用于核物理、空间设备、低温制冷、科学研究等领域。介绍了性价比较高的DT-470低温传感器,从其测温原理、曲线拟合、封装、校准、测量电路及安装等方面进行了说明。提出了一种20K以下温度的高精度测量方法,弥补了Pt1000在低温区测量不准的缺陷。将DT470应用于低温泵产品,测量双级G-M制冷机冷头温度,得到了制冷机二级冷头稳定工作时的温度数据,为低温泵再生操作提供了准确的温度标准。     

Active Targeting Using HER‐2‐Affibody‐Conjugated Nanoparticles Enabled Sensitive and Specific Imaging of Orthotopic HER‐2 Positive Ovarian Tumors

Despite advances in cancer diagnosis and treatment, ovarian cancer remains one of the most fatal cancer types. The development of targeted nanoparticle imaging probes and therapeutics offers promising approaches for early detection and effective treatment of ovarian cancer. In this study, HER‐2 targeted magnetic iron oxide nanoparticles (IONPs) are developed by conjugating a high affinity and small size HER‐2 affibody that is labeled with a unique near infrared dye (NIR‐830) to the nanoparticles. Using a clinically relevant orthotopic human ovarian tumor xenograft model, it is shown that HER‐2 targeted IONPs are selectively delivered into both primary and disseminated ovarian tumors, enabling non‐invasive optical and MR imaging of the tumors as small as 1 mm in the peritoneal cavity. It is determined that HER‐2 targeted delivery of the IONPs is essential for specific and sensitive imaging of the HER‐2 positive tumor since we are unable to detect the imaging signal in the tumors following systemic delivery of non‐targeted IONPs into the mice bearing HER‐2 positive SKOV3 tumors. Furthermore, imaging signals and the IONPs are not detected in HER‐2 low expressing OVCAR3 tumors after systemic delivery of HER‐2 targeted‐IONPs. Since HER‐2 is expressed in a high percentage of ovarian cancers, the HER‐2 targeted dual imaging modality IONPs have potential for the development of novel targeted imaging and therapeutic nanoparticles for ovarian cancer detection, targeted drug delivery, and image‐guided therapy and surgery.     

Attempts to enhance the properties of EPON 830–methylene dianaline epoxy resin systems by exposure to magnetic fields during thermal curing

This effort's objective was to determine whether enhancements to the properties of fully conventionally cured epoxy resin systems (ERSs) consisting of EPON 830, a diglycidylether of bisphenyl A epoxy resin, and methylene dianaline could be found by thermally curing the resins while simultaneously exposing them to economically generated magnetic fields (MFs). Stoichiometric mixes were thermally cured with one of the following profiles: 5 at 121°C or 4 h at 149°C. While being thermally cured, they were also exposed to MFs of strengths between 0.1290 and 0.8810 Tesla. Exposed and control specimens were simultaneously generated from the same ERS mix in each run. The resulting specimens were mechanically and thermally tested. This effort determined that under these conditions there were no modifications to the properties of MF-exposed, fully thermally cured, ERSs relative to their associated controls. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 70: 2539–2568, 1998     

830E燃油供给系统误指示分析及改进措施

通过对830E燃油供给系统误指示现象进行分析,发现其根本原因是燃油箱内部隔板设计和安装存在缺陷。从而设计出一套改进方法,从根本上解决此故障的出现。     

迈思肯条码扫描器QX-830帮助食品工厂提高生产自动化管理

条码技术的应用在食品饮料生产行业的应用,大大提高了工艺运行质量和产品管理效率。本文介绍了迈思肯条码扫描技术在某跨国食品制造公司的应用实例,通过阐述该其技术特点和所显示的优越性,展现了这项新技术在食品饮料生产行业的前景。     

凝胶单推-3制备及性能研究

凝胶推进剂是火箭推进和其他燃气发生器的新型待选推进剂。介绍了凝胶单推-3的制备方法,分析了凝胶剂的惰性热分解性能、凝胶黏度、流变性及贮存稳定性对凝胶点火效果的影响,确定GA-13为制备凝胶单推-3较佳的凝胶剂。     

基于HMC830的低相噪低杂散频率源的设计

针对频率源的相噪会恶化采样数据的信噪比,杂散会降低接收机灵敏度,提出了一种低相噪低杂散的设计方法。该方法利用Hittite公司的新推出的集成VCO的锁相环芯片HMC830进行设计．供电部分采用多个低噪声稳压芯片,参考频率源为Pascall公司的OCXO晶振,环路滤波器为无源四阶,使用Hittite PLL Design...     

催化床对凝胶火箭发动机工作过程的影响

为了研究相关喷注参数及催化床结构对凝胶火箭发动机燃烧室内流场及工作特性的影响,运用Fluent软件并基于DPM,k－ε标准湍流模型等,对具有不同催化床长度的单组元凝胶单推－3火箭发动机燃烧室内的工作过程进行了数值模拟;结果表明：催化床长度越长,由于氨气分解率的升高,燃烧室温度反而较低,燃烧室压力随之降低。推进剂液滴与催化床间的交互作用,如渗透距离,也对反应特性有相当重要的影响。