科创中国

提出了一种采用视频监控系统对人行通道口进行双向人流量计数的方法.首先建立发色模型与头部形状模型,采用形态学运算提取人的头部目标,然后跟踪目标建立人头目标移动链,依据目标链位置信息判别行人的进出方向,最后设置感兴趣的检测区域,并对通过该检测区域的行人计数.实验结果表明,该方法能实时有效地统计通道口处双向人流量.

Microchannel heat sink with high heat transfer coefficients has been extensively investigated due to its wide application prospective in electronic cooling.However,this cooling system requires a separate pump to drive the fluid transfer,which is uneasy to minimize and reduces their reliability and applicability of the whole system.In order to avoid these problems,valveless piezoelectric pump with fractal-like Y-shape branching tubes is proposed.Fractal-like Y-shape branching tube used in microchannel heat sinks is exploited as no-moving-part valve of the valveless piezoelectric pump.In order to obtain flow characteristics of the pump,the relationship between tube structure and flow rate of the pump is studied.Specifically,the flow resistances of fractal-like Y-shape branching tubes and flow rate of the pump are analyzed by using fractal theory.Then,finite element software is employed to simulate the flow field of the tube,and the relationships between pressure drop and flow rate along merging and dividing flows are obtained.Finally,valveless piezoelectric pumps with fractal-like Y-shape branching tubes with different fractal dimensions of diameter distribution are fabricated,and flow rate experiment is conducted.The experimental results show that the flow rate of the pump increases with the rise of fractal dimension of the tube diameter.When fractal dimension is 3,the maximum flow rate of the valveless pump is 29.16 mL/min under 100 V peak to peak(13 Hz)power supply,which reveals the relationship between flow rate and fractal dimensions of tube diameter distribution.This paper investigates the flow characteristics of valveless piezoelectric pump with fractal-like Y-shape branching tubes,which provides certain references for valveless piezoelectric pump with fractal-like Y-shape branching tubes in application on electronic chip cooling.

The large and complex structures are divided into hundreds of thousands or millions degrees of freedom(DOF) when they are calculated which will spend a lot of time and the efficiency will be extremely low. The classical component modal synthesis method(CMSM) are used extensively, but for many structures in the engineering of high-rise buildings, aerospace systemic engineerings, marine oil platforms etc, a large amount of calculation is still needed. An improved hybrid interface substructural component modal synthesis method(HISCMSM) is proposed. The parametric model of the mistuned blisk is built by the improved HISCMSM. The double coordinating conditions of the displacement and the force are introduced to ensure the computational accuracy. Compared with the overall structure finite element model method(FEMM), the computational time is shortened by 23.86%–31.56% and the modal deviation is 0.002%–0.157% which meets the requirement of the computational accuracy. It is faster 4.46%–10.57% than the classical HISCMSM. So the improved HISCMSM is better than the classical HISCMSM and the overall structure FEMM. Meanwhile, the frequency and the modal shape are researched, considering the factors including rotational speed, gas temperature and geometry size. The strong localization phenomenon of the modal shape's the maximum displacement and the maximum stress is observed in the second frequency band and it is the most sensitive in the frequency veering. But the localization phenomenon is relatively weak in 1st and the 3d frequency band. The localization of the modal shape is more serious under the condition of the geometric dimensioning mistuned. An improved HISCMSM is proposed, the computational efficiency of the mistuned blisk can be increased observably by this method.

New generation thermo-mechanical control process(TMCP) based on ultra-fast cooling is being widely adopted in plate mill to product high-performance steel material at low cost. Ultra-fast cooling system is complex because of optimizing the temperature control error generated by heat transfer mathematical model and process parameters. In order to simplify the system and improve the temperature control precision in ultra-fast cooling process, several existing models of case-based reasoning(CBR) model are reviewed. Combining with ultra-fast cooling process, a developed R5 CBR model is proposed, which mainly improves the case representation, similarity relation and retrieval module. Certainty factor is defined in semantics memory unit of plate case which provides not only internal data reliability but also product performance reliability. Similarity relation is improved by defined power index similarity membership function. Retrieval process is simplified and retrieval efficiency is improved apparently by windmill retrieval algorithm. The proposed CBR model is used for predicting the case of cooling strategy and its capability is superior to traditional process model. In order to perform comprehensive investigations on ultra-fast cooling process, different steel plates are considered for the experiment. The validation experiment and industrial production of proposed CBR model are carried out, which demonstrated that finish cooling temperature(FCT) error is controlled within ±25 ℃ and quality rate of product is more than 97%. The proposed CBR model can simplify ultra-fast cooling system and give quality performance for steel product.

简述中小型三相同步水轮发电机无刷励磁的工作原理,介绍交流励磁机中重要部件-旋转整流装置的两种结构形式、原理特点及应用效果.

糯扎渡水电站地处狭谷地区,泄洪最大水头182 m,溢洪道最大泄洪流量31318 m3/s,泄洪功率达55 860MW,其规模为目前国内最大,泄洪消能问题十分突出.为此,在可研阶段对泄洪建筑物布置进行了多方案比选研究,在招标阶段进行了深化研究,结合整体水工模型试验及溢洪道单体、掺气减蚀、护岸不护底、泄洪雾化等专题研究,设计了适合该工程的大型岸边溢洪道,在溢洪道挑流鼻坎下游设置消力塘,有效解决了消能问题.