节能液压站在高炉槽下系统的应用

介绍了节能液压站在高炉槽下系统的应用。节能液压站利用蓄能器来启动电动机,降低电动机启动电流,减少了对电动机的损伤并节约了能源。     

电动机轴电流的危害及消除轴电流的措施

文章通过现场具体设备电动机产生轴电流的实例,分析了造成产生轴电流的原因,简述了电动机产生轴电流导致轴承烧损及轴电流对电动机危害,介绍了如何防止电动机产生轴电流及产生轴电流后应采取的具体措施与消除电动机轴电流所取得的实际经济效益与社会效益.     

中小型电动机降压节能措施

通过对电动机电源电压的调整,以寻求电动机最高运行效率,本文介绍了电动机调压方法及节电量的计算。     

PLC结合单台软起动器控制多台电动机的起动

根据电动机软起动的特性介绍了单台软起动器如何控制多台电动机的起动和停止,以及如何用PLC实现软起动器对多台电动机起停过程的控制。     

大型高压电动机起动分析与计算

大型高压电动机起动分析是工程实施的重要组成部分。本文以某项目电网系统容量小背景下的大功率电动机的起动分析为例,简要介绍了配电系统整体架构、晶闸管固态软启动装置的工作原理及控制方法。重点进行了电动机起动分析计算,并介绍了所采取的综合利用软起动器和改变配电系统运行方式的整改方案,实现了限制电动机起动电流,降低系统阻抗,提高系统容量目标,最终使电动机起动时母线压降满足了相关规范的要求。     

电动机设备节电

工厂的电力消耗,电动机占一半以上。为深入开展电动机的节电工作,请鞍钢副总工程师侯君实同志选译了这篇文章。本文介绍了电动机设备,特别是恒速运行的异步电动机的有关节电措施。     

智能电动机控制器在异步电动机上的应用

介绍智能电动机拉制器原理、起动方式、制动、停车功能,探讨了智能电动机控制器的应用.     

逆交换冷却技术在轧钢主电动机上的应用

本文介绍了在改造φ８２５轧钢主电动机的过程中．经过论证提出了逆交换冷却这一技术并应用到该电动机的冷却系统中，充分发挥了原电动机的能力，为企业创造了经济效益．     

三相异步电动机的节能运行

文章论述了三相异步电动机运行过程中的能量损耗,介绍了电动机节能运行的思路和方法以及变频控制的节能.     

逆交换冷却技术在825轧钢主电动机冷却系统的应用

介绍了在改造关键设备825轧钢主电动机的过程中，经过论证提出了逆交换冷却技术并应用到该主电动机的冷却系统中，从而解决了不更新电动机又能充分发挥电动机能力的难题，为企业创造了可观的经济效益。     

纯电动汽车车载电源性能在环测试平台研究

为研究纯电动汽车车载电源性能,提出并搭建了由异步电动机和直流电动机组成的在环测试平台.异步电动机用来模拟纯电动汽车的牵引电动机,直流电动机用来模拟汽车行驶时的阻力和惯量,对异步电动机和直流电动机分别实施转速控制和转矩控制.分析了电动汽车行驶工况,给出了简单循环工况下参考转速、转距和功率.设计了异步电动机调速系统转速控制器和电流控制器,建立了异步电动机调速系统的数学模型,提出了基于自适应模糊神经网络控制的异步电动机调速系统.仿真和实验结果表明,基于自适应模糊神经网络控制的调速系统明显优于PID控制的交流调速系统,在环测试平台能够较好跟踪参考转速和参考转距的变化.      

大型冷连轧机电机能力选择技术分析

讨论了大型冷连轧机电机转矩工作特性,对电机能力不足进行了详细的分析,提出了提高电机能力的3种方法:提高电机功率,降低电机基本速度和提高齿轮比,并对它们进行了分析比较.在新建冷连轧机电机能力选择时,充分考虑了电机功率、基本转速、齿轮比等因素,提出了电机能力不仅仅指电机功率,更要考虑电机能输出的最大转矩这一关键点,避免了电机能力的不足问题.     

高压泵电机转子轴向窜动故障分析与处理

中板高压除鳞系统高压除鳞泵电机转子发生轴向窜动,造成电机滑动,轴承乌金面磨损严重,致使电机振动增大,温度升高。本文根据高压电机的设计与安装,从电机磁力中心线的位置调整,电机转子扬度以及轴承定位游隙等问题入手,全面阐述并从根本上解决了中板高压除鳞泵电机滑动轴承乌金面磨损及电机异常振动、异响、温升的问题,避免了电机因滑动轴承损坏导致电机扫膛烧坏的可能后果。     

Motor sequencing deficits in schizophrenia: A comparison with Parkinson's disease.

Motor abnormalities occur in schizophrenia (SZ) and may arise from striatal dysfunction. This study examined whether the pattern of performance on simple and complex motor abilities in SZ was similar to that of patients with Parkinson's disease (PD). Quantitative tests of speeded movement and motor and cognitive sequencing were used to assess 25 SZ, 16 PD, and 84 normal controls (NCs). Sequencing performance was also examined with motor rigidity taken into account. Compared with the NC group, the SZ and PD groups were impaired on measures of motor rigidity and motor sequencing. With rigidity accounted for, the SZ group was significantly more impaired than the PD group on motor sequencing; cognitive and motor processes contributed to the motor deficit. Cognitive sequencing performance predicted motor sequencing performance in PD but not SZ. Although both SZ and PD resulted in significant motor and cognitive sequencing deficits, the pattern and correlates of these deficits differ, suggesting that the affected neural systems underlying motor deficits in SZ are different from those involved in PD. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

普通异步电动机变频供电存在问题及变频电动机的特点分析

分析了普通异步电动机采用变频器供电时存在的问题以及变频电动机的特点,阐述了普通异步电动机与变频电动机的区别。     

酸轧生产线3#张紧辊进口电机损坏代用实践

介绍了马钢2130酸轧机组3#张紧辊进口电机在意外烧损后,无同型号电机备件,又不能及时修理的情况下,采用相近类型电机代用的方法,详细给出了该电机代用的机械件制作、调整步骤,电气参数修改及调试过程。     

Peripheral nerve repair in the hand with and without motor sensory differentiation

To investigate the value of motor sensory differentiated nerve repair, we examined a group of 9 patients with motor sensory differentiated nerve repair and a group of 13 patients without motor sensory differentiated nerve repair. The clinical and electroneurographic findings were compared. For the clinical examination, Millesi's scoring system was used. The hand function after motor sensory differentiated median nerve repair was 72% +/- 16% compared with 57% +/- 14% without motor sensory differentiation. The hand function after motor sensory differentiated median and ulnar nerve repair was 53% +/- 12% compared with 43% +/- 24% without motor sensory differentiation. After ulnar nerve repair the achieved values for hand function were high even without motor sensory differentiation. Our results indicate that intraoperative motor sensory differentiation of injured nerves is helpful to reestablish particularly the sensory function in median nerve injuries.     

简析电子热继电器在桥式起重机中的应用

文章介绍了一种由传感器和PLC组成的新型电子热继电器保护装置在桥式起重机中的应用。该保护装置对桥式起重机的三相异步电动机起到保护作用,具有过流、过热、断相等保护功能。性能可靠、稳定,可有效地对异步电动机进行保护,大大减少电动机在使用中的故障。     

Evaluating the effect of superficial temporal artery to middle cerebral artery bypass on pure motor function using motor activation single photon emission computed tomography

OBJECTIVE: We evaluated and analyzed the effect of superficial temporal artery to middle cerebral artery bypass for internal carotid artery occlusion on pure motor function using motor activation single photon emission computed tomography. METHODS: Motor activation single photon emission computed tomographic (SPECT) images were obtained for nine patients who had undergone superficial temporal artery to middle cerebral artery anastomosis for symptomatic internal carotid artery occlusion. All motor activation SPECT images using the finger opposition task on the affected side were obtained before bypass surgery and at 1 week, 1 month, and 3 months after bypass surgery. The results of motor activation single photon emission computed tomography were expressed as negative or positive. RESULTS: Before bypass surgery, the resting SPECT images revealed reduction of cerebral blood flow (CBF) on the affected side in all nine patients. The results of motor activation single photon emission computed tomography in three patients were positive. One week after bypass surgery, the results of the resting and motor activation CBF studies did not demonstrate any marked changes. One month after bypass surgery, the resting CBF increased in four patients. The results obtained for two of the patients revealed preoperative positive motor activation. The results of motor activation single photon emission computed tomography obtained for five patients were positive. Three months after bypass surgery, eight patients experienced improvement in the resting CBF, and the results of motor activation single photon emission computed tomography obtained for seven patients were positive. Among these, the results of preoperative motor activation single photon emission tomography obtained for four patients were negative. CONCLUSION: Superficial temporal artery to middle cerebral artery bypass is useful not only for resting CBF but also for pure motor function based on motor activation SPECT images. From the preoperative motor activation study, it was concluded that patients with preoperative positive motor activation could attain the effect of bypass earlier than patients with preoperative negative motor activation.     

Disturbance of Motor Imagery After Cerebellar Stroke.

The authors studied the possible involvement of the cerebellum in nonexecutive motor functions needed for a normal performance of complex motor patterns by analyzing (using chronometric evaluation) finger movement sequences and their respective motor imagery (a mental simulation of motor patterns). Patients suffering from a cerebellar stroke (n=11) were compared with aged-matched control volunteers (n=11). Patients that had apparently recovered from a unilateral cerebellar stroke showed a marked slowing of motor performance in both hands (ipsi- and contralateral to lesion). This effect was accompanied by a similar slowing of motor imagery, suggesting that the cerebellum, traditionally implicated in the control of motor execution, is also involved in nonexecutive motor functions such as the planning and internal simulation of movements. (PsycINFO Database Record (c) 2010 APA, all rights reserved)