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NUMERICAL SIMULATION OF TIP-CLEARANCE FLOW IN CASCADE 总被引:1,自引:1,他引:0
Chen Long Yang Chen jun Wang Guo qiangSchool of Naval Architecture Ocean Engineering Shanghai Jiaotong University Shanghai China 《水动力学研究与进展(B辑)》2003,15(1)
1 . INTRODUCTIONTip clearanceflowsoccurinvariousengineer ingapplicationssuchasaxial flow pumpsandduct edpropellers .Theinertialforcesactinguponthefluidinthenarrow gapbetweenbladetipandthesurroundingwallaresufficientto generateatipleakagevortexonthesuctions… 相似文献
995.
996.
描述了一个局域网视频广播接收器的设计。发送端以计算机按UDP/IP的方式向局域网中发送视频广播,在接收端利用FPGA器件设计的接收器对广播进行接收、缓冲、格式转换,以电视作为显示终端,并介绍了在FPGA器件中所设计的各个模块。 相似文献
997.
A semiconductor factory contains hundreds of pieces of equipment. More reliable service by equipment managers is required to increase the utilization of equipment and improve product quality and yield. Therefore, developing a reliable service management scheme (SMS) for semiconductor factory management systems is essential. This study presents an SMS that applies Jini Technology and uses the design by contract technologies. The SMS has error-detecting and function-replacing capabilities. The SMS detects the malfunctioning of an equipment manager (service) and sends an event notice to the factory manager. The GEV in the SMS archives the credit values of all of the equipment managers so that the factory manager can select better equipment managers for service by checking their credit values. The illustrative example and the evaluation of the reliability improvement reveal that the proposed SMS provides an efficient, reliable, fault tolerant, and cost-effective mechanism for semiconductor factory management systems. Lastly, this illustrative example is successfully implemented and demonstrated and the core technology of SMS is transferred to and commercialized by Charming Systems Corporation. 相似文献
998.
We present measurements of the ultrafast optical response of La2–x
Sr
x
CuO4 single crystals at two different doping levels (x=0.15, 0.07) as a function of temperature. Owing to the 40-fs time resolution of our experiment, we are able to measure both the build-up and the decay of the ultrafast signal. We show for the first time that the temperature dependence of the transient reflectance amplitude tracks the thermal depletion of the superfluid density. At low temperature we identify a new regime characterized by an extremely long, temperature-dependent rise-time (3 ps). The doping dependence of the relaxation rate suggests that this is sensitive to the scattering of quasiparticles by low-energy spin excitations. 相似文献
999.
宣汉——达县地区飞仙关组储层预测方法研究 总被引:1,自引:1,他引:0
在宣汉-达县地区,以往仅依据地震属性来预测飞仙关组储层分布,钻探结果与实际情况不符,为此本文提出量化分析预测结合主参数分析的新方法和新思路。在量化分析中首先对飞仙关组储层进行高分辨率反演,获得储能系数图;然后结合主振幅剖面和主频率剖面分析,对储层进行预测。在研究区,本方法的预测结果与实钻情况相吻合。 相似文献
1000.
The major steps of sewerage rehabilitation include inspection of sewerage, assessment of structural conditions, computation of structural condition grades, and determination of rehabilitation methods and materials. Conventionally, sewerage rehabilitation planning relies on experts with professional background that is tedious and time-consuming. This paper proposes an automation model of planning optimal sewerage rehabilitation strategies for the sewer system by integrating image process, clustering technology, optimization, and visualization display. Firstly, image processing techniques, such as wavelet transformation and co-occurrence features extraction, were employed to extract various characteristics of structural failures from CCTV inspection images. Secondly, a classification neural network was established to automatically interpret the structural conditions by comparing the extracted features with the typical failures in a databank. Then, to achieve optimal rehabilitation efficiency, a genetic algorithm was used to determine appropriate rehabilitation methods and substitution materials for the pipe sections with a risk of mal-function and even collapse. Finally, the result from the automation model can be visualized in a geographic information system in which essential information of the sewer system and sewerage rehabilitation plans are graphically displayed. For demonstration, the automation model of optimal sewerage rehabilitation planning was applied to a sewer system in east Taichung, Chinese Taiwan. 相似文献