水泵电机变频调速应用与分析

本文根据株洲硬质合金厂（以下简称“工厂”）的供水加压站的原实际工况，经应用变频调速技术后达到供水系统压力稳定，设备运行可靠，节约电能的实例，对供水变频控制系统，调速节能原理，变压变频调速原理，控制功能进行理论分析与计算，从实践与理论两个方面解剖变频调速技术的应用。     

变频技术的发展应用及普及前景

变频调速技术有着很好的发展及应用前景。本文概述变频调速技术在我国的发展和应用及影响变频技术推广的原因，并阐述了变频技术新的进步。最后指出，变频器的功能并不是越多越复杂越好，而应按照实际需要选择适用的变频器。     

热带轧机主传动交-交变频与交-直-交变频调速系统的技术经济比较

以某工程热带轧机为例，对热带轧机主传动调速系统采用交-交变频调速和交-直一交变频调速的优缺点进行比较，总结出交-直-交变频调速系统将是今后热连轧机主传动变频调速系统的发展方向。     

影响水泵变频调速节能效果的主要因素探讨

变频调速是实现水泵节能的重要手段之一。但在应用中如果对其影响因素缺乏综合考虑，不通过精确的计算，不认真分析工艺条件而盲目采用变频调速，往往是投入不少，却难以获得预期的效益，也给变频调速的推广应用带来了负面的影响。本针对影响其调速范围和节能效果的一些因素，主要是调速泵自身效率、配套电机效率、并列运行的其它水泵的协同效率、不同管路特性曲线对其影响以及2种变频供水方式的对比，通过分析，明确了变频调速应用的一些特点和注意事项。     

水泵变频调速控制系统

变频调速节能技术是８０年代科技发展涌出现的一种交流调速节能技术，介绍了水泵变频调速控制的节能原理及变频调速系统的构成，应用特点及效果，具有实际应用价值。     

高压离心通风机采用变频调速应注意的问题

高压离心通风机采用变频调速应注意的问题袁宏，吴德荣机械部第五设计研究院（邮编：天津３００１９０）变频调速技术及装置是近几年发展起来的一门新技术，它用于风机和水泵调速可以节约大量的能源，因此，在工业及民用系统中，得到了广泛的发展和应用。但是，变频调速装...     

变频调速在棒磨山铁矿的应用与推广

介绍了滑差调速和变频调速的原理及特性，并对两者进行了比较之后得出结论；从现阶段应用和发展趋势看，后者优越于前者。     

高压变频调速系统的应用

目前高压变频调速技术在中国市场上有着很好的发展和应用前景。本文对高压大功率风机、水泵的节能原理进行了分析，给出了H桥串联式高压变频调速装置的方案及原理，并介绍了国产560kW，6000V高压变频调速装置的组成、技术特点和工程应用。工程应用的结果表明，该系统完全满足工艺需要，在工业节能上已达到较好的效果。     

变频调速技术在风机节能改造中的应用

本介绍了风机变频调速的节能原理，均热炉风机采用变频调速技术进行改造的方法，并分析了改造后的经济效益。     

1200mm中板精轧机电动压下变频调速技术的开发应用

重庆特殊钢集团公司中板分厂１２００ｍｍ精轧机电动压下系统采用变频调速新技术，调速范围宽，调速准确、方便，提高了轧机压下精度和生产率，取得了较好的经济效益     

Hysteresis in Shallow Water Sloshing

Hysteresis in sloshing of shallow water in horizontally excited tanks is explored experimentally. In particular the wave response to relatively large shaking amplitude near the resonant frequency is investigated for two tank configurations: a tank with horizontal bottom and vertical walls, and a tank with horizontal bottom and sloping beaches. The hysteresis behavior is clearly observed within a narrow frequency range around the shifted resonant frequency. The wave response is either in the form of smooth nonbroken waves or in the form of violent breaking waves for exactly the same set of parameters depending only on how the target oscillation frequency is tuned: i.e., whether the forcing frequency of the prior state is higher or lower than the target frequency. The consequence is that it is not possible to define a unique value for the jump frequency as it depends on the direction of the frequency tuning.     

北极涛动对华北沙尘暴频次的影响

This study has investigated the influence of Arctic Oscillation (AO) on dust storm frequency in North China in spring seasons during 1961-2007. There is a significant linkagebetween dust storm frequency and AO; a negative (positive) AO phase is related to an in-creased (decreased) dust storm frequency in North China. This relationship is closely related to changes in the cold air activity in Mongolia. The cold air activity exerts large impacts on the dust storm frequency; the frequency of cold air activity over Mongolia not only positively cor-relates with the dust storm frequency in North China, but also shows a long-term decreasing trend that is an important reason for the long-term decreasing of dust storm frequency in North China. The AO has large influence on the frequency of cold air activity over Mongolia; a negative (positive) AO phase is highly related to an increased (decreased) frequency of cold air activity over Mongolia, which results in an increased (decreased) dust storm frequency in North China.     

Effects of syllable frequency and syllable neighborhood frequency in visual word recognition.

Three experiments were carried out to analyze the role of syllable frequency in lexical decision and naming. The results show inhibitory effects of syllable frequency in the lexical decision task for both high- and low-frequency words. In contrast, the effect of syllable frequency is facilitatory in the naming task. A post hoc analysis revealed the important role played by the number of higher frequency syllabic neighbors (words that share a syllable with the target) in the lexical decision task and the role of the frequency of the first syllable in the naming task. Experiment 3 manipulated the neighborhood syllable frequency directly by comparing words with few higher frequency syllabic neighbors and words with many higher frequency syllabic neighbors in the lexical decision task; an inhibitory neighborhood syllable frequency effect was found. The results are interpreted in terms of current models of visual word recognition and word naming. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

晶闸管在国产双频淬火机上的应用

介绍了共昌双频（低中频）感应淬火机的晶闸管将工频电能变频为低中频电能的变频过程,并成功地应用在共昌双频（低中频）感应淬火机冷轧工作辊热处理的情况。通过与比利时OSB双频（工中频）感应淬火机的对比分析,证实其达到了进口设备的性能,获得了冷轧辊所需工艺质量目标,开辟了一条高效率、低投入的国产化新路。     

基于高阶同步压缩变换的行星齿轮箱声音信号共振频带特征提取

建立了非平稳运行工况下行星齿轮箱共振频带内的声音信号解析模型,揭示了齿轮故障特征在声音信号共振频带内的分布规律。根据共振频率不随转速变化的特点定位了齿轮箱共振频率,为在共振频带内提取齿轮故障特征奠定基础。针对传统时频分析方法时频分辨率低的缺陷,研究了基于高阶同步压缩变换的时变故障特征提取方法。通过数值仿真和实验信号分析,验证了所提出的声音信号模型与行星齿轮箱故障特征分布规律的正确性,以及利用高阶同步压缩变换方法提取共振频带内行星齿轮箱故障特征的有效性。      

电镀锡板木纹缺陷的形成原因及解决措施

探讨了电镀锡带钢在软熔工艺段采用工频电阻软熔时形成木纹缺陷的原因,提出了消除木纹缺陷的新技术——变频电阻软熔。它通过改变软熔电源的频率 (50～200Hz)能消除木纹缺陷,不同工艺条件下,消除木纹缺陷所需要的电源最低频率值不同。详细介绍了该技术在400m/min电镀锡线上的应用情况。与普遍采用的工频电阻加高频感应的组合软熔工艺相比,该技术既提高了用电效率,也提高了电镀锡板表面的抗划伤性,尤其适合高速电镀锡线。     

Thrust Analysis of a Fish Robot Actuated by Piezoceramic Composite Actuators

In this work, a three-dimensional (3D) Computational Fluid Dynamics (CFD) model was built to simulate the tail fin motion of a fish robot actuated by a piezoceramic composite actuator, and to determine the maximum thrust tail-beat frequency. A simulation of the tail fin at a tail-beat frequency was performed to confirm measured thrust data from a previous study. The computed and measured thrusts were in good agreement. A series of thrust simulations were conducted for various tail-beat frequencies to confirm the maximum thrust frequency that was obtained from thrust measurements in the previous study. The largest thrust was calculated at a tail-beat frequency of 3.7 Hz and vortices around the tail were fully separated. The calculated maximum thrust tail-beat frequency was in good agreement with the measured frequency. Flow characteristics during tail fin motion were examined to explain why the largest thrust occurred at this particular tail-beat frequency.     

高压变频调速技术在风机、泵类应用中的节能分析

着重介绍了高压变频器在风机、泵类设备中节能情况,对其节电情况进行分析.结果表明,风机、泵类设备采用高压变频器进行调速节能改造,具有投资省,见效快等特点.     

Speed, spatial-frequency, and temporal-frequency comparisons in luminance and colour gratings

The perceived speed, temporal frequency, and spatial frequency of matched colour and luminance gratings were compared in separate experiments. The large factor by which colour gratings are perceived to be slower moving than matched luminance gratings cannot be explained by systematic differences in the perceived spatial frequency or in the perceived temporal frequency of the two types of grating.     

视频网络应用于资源型企业的探索

通过对陕西有色金属控殷集团有限责任公司采取视频网络的迫切性和重要性的阐述，分析了陕西有色金属控股集团有限责任公司信息化的现状，提出了以视频网络构建陕西有色金属集团信息化系统的思路，并根据视频模式图阐明视频网络的可行性。