大容量同轴电机多相整流的可逆调速系统设计

轧钢生产线上常规的同轴电机控制的拓扑结构和控制方式是由2台6相整流系统分别为2台电机供电，主从控制，实现2台同轴电机运行。由于大容量6相整流产生脉动电流大、谐波大，影响电机使用寿命，因此，需要在直流回路增加平波电抗器，但平波电抗器的增设又会增大电机的机电时间常数，影响电机运行动态特性。针对上述问题，提出了一种大容量同轴电机多相整流的可逆直流调速系统，对现有同轴电机拓扑结构和控制方式进行改进，通过整流变压器和可逆整流装置，对交流侧电网构成多相整流，整流变压器二次侧电压相位错开，以减少电网谐波，提高功率因数。     

来冶三期锌电解整流的谐波计算方法及计算公式探析

以来冶锌电解整流的谐波计算为例，全面系统地分析和探讨各种谐波计算方法的特征及其实用性。对谐波的计算作了较为完整的介绍，也是对来冶三期工程锌电解整流谐波计算正确性的论证。     

基于多相整流的船舶电力推进系统谐波抑制

变频器等电力电子设备在船舶电网中的使用,将使变频器输入回路产生大量谐波.为减小谐波对电网的污染,对6脉波、12脉波、24脉波整流器的输入侧电流谐波进行了分析,对船舶电力推进系统不同工况下的网侧电流谐波进行了仿真研究.仿真结果表明,多相整流技术是抑制谐波的有效方法,整流相数越多,变频器注入电网的谐波含量越小;24脉波整流应用在船舶推进系统上可大大减小船舶电网的谐波含量,有效地提高电网品质.     

谐波滤除装置在整流设备上的应用

本文主要介绍了谐波源整流系统设备对电网的污染、对设备的危害及电能损耗,简述了谐波滤除装置的工作原理及其在整流设备上的应用.     

2800mm中厚板轧机主传动中的整流技术及其对谐波的影响

安钢２８００ｍｍ中厚板轧机，为了减少谐波的产生，在主传动系统中采用了先进的２４相整流技术，文中对这项技术的设备组成及原理进行了阐述，并作了谐波分析，说明了采用该项技术的优点和必要性。     

铝电解整流机组滤波器参数设计的分析

针对铝电解整流机组的特点,进行了整流机组在考虑阀侧电抗和不考虑电抗下的功率因数和谐波电流,根据分析结果认为,实际的铝电解整流机组阀侧电抗值较大,使得位移因数和谐波电流同时下降很多,以往不考虑整流变压器漏电抗影响的谐波和位移因数分析会带来较大的误差,从而影响整流机组滤波器参数的确定。     

串接石墨化整流系统谐波研究

根据串接石墨化整流系统的负荷特性，从理论上分析了各种运行状态下的谐波含量，提出了合理的治理方案。     

整流装置高次谐波污染的危害及抑制措施

介绍了整流装置高次谐波污染的产生原因极其对电网和其它用电设备的危害性，并通过理论和实例分析和介绍了对高次谐波污染的抑制措施，希望对从事电气技术工作的同行有一定的参考价值。     

整流系统无功补偿兼滤波装置运行效果分析

本文首先对电解铝整流系统的补偿及谐波治理方式进行了描述,同时结合实际测试波形数据对常用谐波治理方式改善效果进行了分析,对电解铝整流系统的无功补偿及谐波治理的方案设计等具有实际的参考意义。     

整流装置在运行中产生非特征谐波

大功率整流装置不仅产生较大的特征谐波，在一定条件下还能产生非特征谐波，有时可能达到危及安全运行的程度。本文就非特征谐波的危害，产生原因和抑制办法进行初步的分析和探讨。     

转炉炉壳热应力分析

根据实际转炉建立实体模型。以有限元为手段,考虑了炉衬和炉壳材料的物性参数随温度变化的特点和炉衬与炉壳之间膨胀间隙,计算了转炉炉壳在温度载荷和炉衬膨胀压力同时作用下的热应力。所得结果可为转炉炉壳设计提供依据。     

焦炭热性能指标意义浅析

通过对焦炭在高炉内的历程及其变化规律的剖析,阐述焦炭热性能指标的意义,形象地把焦炭在高炉内的损耗分为三部分(M1,M2,M3)。指出M2对焦比及焦炭价格有一定的指导作用。     

Results of treatment of cancer of the cardia

Cancer of the cardia is traditionally discussed with cardiac cancer of the lower portion of the esophagus and upper gastric cancer invading the esophagus, and the specific characteristics of cancer of the cardia have never been clearly defined. We reviewed the outcome of 172 patients with adenocarcinoma of the cardia who had undergone radical surgery between 1949 and 1994 in the Division of Gastrointestinal Surgery of the Cancer Institute Hospital. The centers of the tumors were located within 2 cm above and below the boundary between the esophagus and the stomach, and their longitudinal diameter was less than 8 cm. We divided the patients into an early period (1949-1979; n = 79) and a late period (1980-1994; n = 93), and focused on the historical transition. There were no differences in patient gender or histology between the two periods. However, the late period was associated with fewer cases of esophageal invasion and shorter longitudinal diameter, as the age of the population advanced. The number of advanced cancers such as the localized and infiltrative type had decreased, and early cancer and early clinical stage had become more common, but despite the fact that the number of early cancers had increased, extended dissection, such as thoracic and paraaortic lymph node dissection, was performed more frequently. By clinical stage, the long-term outcome markedly improved in Stage I patient in the late period, and tended to improve in Stage II and III patients. This appears to have been attributable to the prevention of micrometastasis by extended dissection, although the number of early cancers is another major potential cause. There were no differences in the outcome of Stage IV patients between the two periods, and further advances in multimodality therapy must be awaited. The range of resection is basically proximal gastrectomy, and if there are adequate indications, the prognosis is favorable. In view of the status of lymphatic flow and lymph node metastasis, and long-term results, lateroaortic lymph node dissection is important. Since the number of early cancer patients has been increasing, if intraabdominal recurrence is prevented, intrathoracic lymph node dissection will contribute greatly to the outcome of such patients.     

The effect of amount of possession of the trait of hostility on accuracy of perception of hostility in others.

Some theories of personality hold that an individual's perception of others is influenced by his own personality characteristics; more specifically, that a trait of low social value will be projected more into others, and that insight into the possession of these characteristics reduces this distortion. These 2 hypotheses were tested by having a group of college students rate each other (including themselves) on degree of friendliness or hostility. Agreement with group rating about self yielded the insight score. In general, the hypotheses were supported; the "friendly" Ss were most accurate in their perception of others, and insight was positively associated with accurate perception. From Psyc Abstracts 36:04:4HL16M. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Comparison of rates of infection of two methods of emergency ventricular drainage

The rates of infection of two methods of external ventricular drainage in use at Atkinson Morley's Hospital--namely, (a) percutaneous drainage with Rickham reservoirs and (b) tunnelled ventriculostomies--were compared in this retrospective review. Percutaneous drainage of CSF with Rickham reservoirs was associated with a 27% rate of infection as identified by positive microbiological cultures; tunnelled ventriculostomy catheters had a 10% infection rate. The difference in the infection rate between the two methods was statistically significant (P < 0.015). Other variables examined, including the age and sex of the patients and the reasons for ventricular drainage, were not associated with an increased rate of infection. Most infections from either method were caused by a coagulase negative staphylococcus. The average duration of ventricular drainage before identification of positive cultures was 5.7 days for Rickham reservoirs and 6.0 days for ventriculostomies.     

Effect of antibiotics of chemotaxis of human leukocytes

The effect of 20 different antibiotics on chemotaxis by human neutrophils was studied. Human leukocytes incubated with chloramphenicol, rifampin, sodium fusidate, and tetracyclines in vitro showed markedly depressed migration. The mechanisms by which these antibiotics affect leukotaxis are discussed.     

Quality of life of relatives of mental patients

Usage of quality of life of psychiatric patients' relatives as the parameter of estimation of the quality of psychiatric care is considered. By means of standard questionnaire elaborated by the authors as well as by means of both individual and group conversations the quality of life was analyzed in 40 relatives which lived together with psychiatric patients. Different spheres of their life and difficulties (financial, social-psychologic, production) were examined in families with such patients. The defects of psychiatric care that had direct influence on the quality of life of the psychiatric patients' relatives are outlined.