变频调速在工厂水系统中的节能应用

以济钢第一炼钢厂除尘加压泵组供水系统为例,介绍了变频调速恒压供水系统的结构及工作原理。变频调速恒压供水系统采用先进的控制技术与水泵机组相结合,具有高效节能、自动化程度高、操作灵活方便、供水压力稳定等特点。     

基于PLC与内置PID变频器的恒压供水系统设计

对供水系统变频恒压调速控制和节能原理进行简单分析后,对基于PLC和内置PID变频器的恒压供水系统总体方案和系统工作过程中进行了详细探讨与研究.该系统工作运行可靠、控制精度较高,节能效果明显,具有非常广阔的应用前景和推广价值.     

水泵变频调速的应用及节电效果

变频恒压供水技术现得到成熟、广泛的应用。笔者通过一次变频恒压供水系统改造的实践经验与有关理论相结合．对水泵变频调速的节能原理进行探讨分析。     

变频调速技术在全自动恒压供水系统中的应用

介绍变频调速系统的结构、功能和特点,以及变频调速技术在韶冶某小区全自动恒压供水系统中的应用。实践表明,该系统设计合理,运行可靠。     

变频调速装置在供水系统中的应用

叙述了变频调速装置应用在风机水泵方面的节能原理、装置特点、变频调速恒压供水系统原理及其应用后的节能效益，并建议工矿、企事业单位积极推广应用。     

变频调速技术在生产中的节能应用

简要介绍了变频调速技术的节能原理,并以供水系统为例,分析变频调速装置在供水系统应用的现状与效果,除了节能效果外,变频调速装置还可以改善工艺状况。     

PLC在恒压供水系统中的应用

较详细地介绍了采用PLC控制的变频调速恒压供水系统,该系统采用PLC进行逻辑控制,用变频器进行压力调节,自动控制水泵投入的台数和电机转速,在保持恒压状况下,达到控制流量的目的.系统结构简单,运行稳定,节约能源.     

GZB系列变频恒压自动供水控制系统在尾矿库循环供水中的应用

通过对该技术的实际应用,阐述了变频恒压自动供水控制系统的工作原理。如何将变频恒压自动供水控制系统设计到循环供水系统。同时,特别介绍了该系统的应用效果和存在的问题及改进。     

水泵变频调速节能改造的能效分析

针对合同制能源管理对供水系统改造产生的积极节能效果,以及改造方式影响水泵调速范围和节能效果的一些原因进行了分析,明确了供水系统变频调速改造应用的一些特点和注意事项。     

变频调速系统在恒压供水中的应用

采用变频调速技术的恒压供水系统，实现了水泵电机的无级调速，依据用水量的变化，自动调节系统的运行参数，从而保持水压恒定，以满足用水要求，同时以其节能、安全、高品质的供水质量等优点，成为当今最先进、合理的节能型供水系统，在实际中得到了广泛应用。     

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。     

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.     

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。     

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.     

浅析《野草》的版画特征

鲁迅先生一生热爱美术作品,对版画中木刻兴趣尤甚.<野草>作为其"写心之作",亦呈现出一些与木刻版画一致的审美特征:一是具有木刻版画的色彩特征,多对比、多冷色,有阴郁的美感;二是具有木刻版画的力度特征,环境描写、人物刻画处处刀锋毕现,遒劲有力,有一种"力之美".     

四辊破碎机车刀架的改造

针对四辊破碎机车刀架车削中存在的几个问题,详细介绍了电动车刀架的结构和工作原理,建立主要设计参数的数学表达式,并进行适当的分析。改造后,这种电动车刀架运行平稳、可靠、方便、省力,取得了预期的效果。     

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.