基于Windows 2000下开放式数控系统软件的开发

基于PC机和Windows操作系统的开放式数控系统是数控技术的大势所趋.文章首先介绍了数控机床的发展历程,并分析传统数控系统不足和基于PC的开放式数控技术的优点的基础上,论述了基于Windows2000操作系统下,开放式数控系统软件的研究和开发过程.重点阐述了在Microsoft Visual C 下系统人机交互界面的设计、工控PC机控制运动控制卡的接口软件模块、PC机与主轴控制变频器的RS485串行口通讯软件模块的的编写,同时给出了主要程序代码.该数控系统现在已经在调试之中,并且达到了预期的加工精度和效果.     

TCR+FC型无功补偿技术在矿井提升系统中的应用

提升机是采矿企业广泛使用的大功率、高耗能的生产设备之一,矿井提升系统普遍采用电力电子器件构成的整流装置对其直流电机进行供电和控制。提升机在采矿过程中需要频繁地启动、停机,对电网的无功冲击和谐波污染使供电系统的安全稳定性受到严重影响。本文以国内某铅锌矿盲主井提升系统为研究对象,提出晶闸管控制电抗器(Thyristor Controlled Reactors,TCR)和固定电容器组(Fixed Capacitors,FC)相结合的无功补偿与谐波治理方法。针对提升机运行过程的特殊性和复杂性,给出无功补偿装置的具体电路设计、参数计算等的方法。提出的无功补偿与谐波治理技术对无功补偿装置的工程研究和开发提供一定的参考和指导,对提高电网的供电质量,保障矿井安全、稳定、高效生产具有十分重要的意义。     

AC susceptibility and FC-ZFC magnetic properties of SrTb_xFe_(12-x)O_(19) and SrTm_xFe_(12-x)O_(19) hexaferrites:a comparative study

In this comparative study,Tb and Tm substituted Sr-hexafe rrites(HFs) with the chemical compositions of SrTb_xFe_(12-x)O_(19) and SrTm_xFe_(12-x)O_(19)(x=0.00,0.02 and 0.04) were fabricated via citrate sol-gel approach.The AC susceptibility and FC-ZFC magnetization were investigated.The product structure and morphologies were also investigated via XRD,TEM and SEM along with EDX.Measurements of temperature dependence of magnetization M-T and AC magnetic susceptibility versus temperature were carried out.The various synthesized HFs displayed ferrimagnetic behavior within 10-325 K.At lower temperatures,super-spin glass-like behavior was noticed.Neel-Arrhenius and Vogel-Fulcher models were employed to explore the experimental data of AC susceptibility.     

电力变压器蒸发冷却装置FC液位监控系统

介绍电力变压器蒸发冷却装置的液位控制系统,该系统以嵌入式以太网芯片为核心构成网络终端,实现了冷却介质FC液位的远程监测调节。     

FC＋TCR型SVC研究

本文研究了FC＋TCR型SVC的特性以及在电力系统电压调节中的应用。对TCR的基本原理与特性进行了分析,并Simulink．做了仿真验证,仿真结果表明,FC＋TCR型SVC能够有效的调节电网电压。     

基于神经元动态补偿的模糊控制及其应用

提出一种基于神经元动态补偿的模糊控制策略 ,应用于一液压位置系统控制实验结果表明 ,所提出的控制策略可行 ,对进一步改善控制系统的鲁棒性及提高模糊系统控制精度具有明显积极作用 ,是一种有效的复合控制方法 .     

基于PC的FC仿真卡系统设计

由于航电系统测试总线技术的迅速发展,急需地面仿真设备与之对应,实现实验室环境下的FC网络功能测试。在充分理解航电系统FC通信协议的基础上,利用FC-AE-ASM协议对FC网络地面仿真设备进行开发,并基于PC搭建仿真环境,以满足航电系统中FC仿真卡的设计思想,同时进行原理验证和功能测试。FC仿真卡的设计有力的推动了国内光纤通道通信技术的进一步发展。     

可编程控制器在输煤控制系统中的应用

本文较系统的介绍了江苏省新海发电有限公司输煤程控系统。涉及硬件选型与布置,工艺流程要求,联锁保护控制逻辑制作,FC功能块组态方法,画面功能制作。在百万机组扩建中终端设备大量使用了Profibus总线耦合器。为同类系统的设计使用提供了借鉴。     

FC+TCR在牵引变电所的应用

固定补偿方式难以满足供电部门规定的负荷功率因数标准,但其具有很多优点,可考虑固定补偿+动态补偿相结合的方式.分析FC+TCR(单臂)动态补偿方式,且仿真结果表明补偿效果良好,表明此方案适用于固定补偿装置过补偿严重的变电所.     

EFFECTS OF HEXASULFOBUTYLATED C60 ON THE GASTRIC CIRCULAR MUSCLE OF GUINEA PIG

The effects of hexasulfobutylated (FC₄S), the fullerene derivative on the contraction of smooth muscle were tested pharmacologically on the circular muscle of stomach of guinea pigs. The effects of monomalonic acid C₆₀ (MMA C₆₀) on the same preparations were compared. The effects of those compounds on the taenia coli, portal vein and vas deferens of guinea pigs were also tested. The FC₄S did, while MMA C₆₀ did not elicit contracture of the circular muscle of stomach and taenia coli. Both FC₄S and MMA C₆₀ did not elicit contraction on the portal vein and on the vas deferens of the guinea pig. Prazosin (0.5 μM) or propranolol (0.5 μM) did not alter the FC₄S elicit contracture of the circular muscle of stomach. However, atropine (0.01, 0.1 and 1 μM), tetrodotoxin (0.1 μM) or low calcium medium decreased reversibly the FC₄S elicited contracture of the circular muscle of stomach. The effect of FC₄S on the contracture of the gastric muscles was also tested using various muscarinic receptor subtype antagonists. 4-DAMP (1 μM), muscarinic M3 receptor antagonist, and tropicamide (1 μM), muscarinic M4 receptor antagonist, did not alter the contracture elicited by FC₄S. Pirenzepine (0.1 μM), muscarinic M1 receptor antagonist, and methoctramine (0.25 μM), muscarinic M2 receptor antagonist, significantly decreased the FC₄S elicited contracture of the circular muscle. Atropine (1 μM) or tetrodotoxin (0.1 μM) completely blocked the FC₄S elicited contracture of the circular muscle of stomach. It is concluded that FC₄S elicited contracture of the circular muscle of stomach. The effect may be due to FC₄S acts on the cholinergic cells existed in the gastric muscle and indirectly activating the tetrodotoxin dependent releasing of the transmitters from the cells, then, activating the muscarinice M1, M2 receptors in the muscle eliciting the contractures.