黄瓜冷激处理过程分层数值模拟与传热特性分析

为研究果蔬冷激过程中内部组织传热特征,根据果蔬生理结构特征建立并验证了柱状果蔬的分层传热模型。利用所建模型分析了以空气和冷水为处理介质时流速、果蔬尺寸、组织热物性差异对黄瓜冷激传热过程的影响。结果表明,所建模型在黄瓜中心、距中心2R/5及4R/5(R为黄瓜半径)处的平均温度误差(MEE)分别为0.423、0.377和0.842℃,最大绝对误差(MAE)为1.713℃,具有较高精度。空气流速由1 m/s增至5 m/s过程中,黄瓜降温速率增幅较大,对流换热热阻对传热过程影响较大;水流速度由0.2 m/s增至1.8 m/s过程中,黄瓜中心处降温速率增幅较小,果蔬内部热阻对传热过程具有较大影响。以水为处理介质时,物性差异的影响大于以空气为处理介质时的影响。研究结果可为果蔬冷激处理工艺优化提供理论参考。     

Effects of Cold Drawing and Water Quench Process on Mechanical Properties Prestressed Wires

Effects of cold drawing and water quench process on mechanical properties of prestressed wires have been studied in laboratory. It shows that sorbitized treat using water quench replacing lead quench is possible for Carbon steels prestressed wires. The cold drawing and water quench process which enable the mechanical properties of wires reaching specified demand of present standards are determined.     

Mechanism of Photocatalytic Activity of TiO2 Doped by Fe(III)

Ti_(4)O_(8) super cell are formated and geometry optimized.The band gap, Fermi level, density of states of TiO_(2) doped by Fe(III) have been simulated with relativistic density functional theory and Plane Wave Pseudo Potentials (PWPP). The band gap of TiO_(2) doped by Fe(III) become narrow, and density of states are enhanced. It can decrease composition of e~(-) and h~(+), Photocatalytic activity of TiO_(2) are enhanced by doped Fe(III).     

Frequency Shift of Proca Light Caused by a Single Polarized Linearized Gravitational Wave

When light spreads in gravitational wave, its frequency is changed. Usually considering frequency gravitational shift, the rest mass of the photon is neglected. According to Proca equations of weight electromagnetic wave the authors investigate the Frequency shift of Proca light. The results of numerical estimation show that frequency shift of the photon has a small change when considering the rest mass of the photon and it is not detected at present experimental condition.     

Improve the Hardware of Watt-hour Meter Reading Figure in Machinery to Achieve to Long-range Reading

It is a time-consuming job that reading electricity meter from door to door every month. So, improving the hardware of traditional watt-hour meter will change the machinery digit into electricity digit, and read electricity meter in long-rang with wireless carrier. Aautomatic collection, transfer and handling are applied to electricity energe manage system. It overcomes the weakness of traditional mannered reading model. The feature is that simple change the circuit to get the effect in low cost.     

Experimental research on dynamical characterristics of rock in fei xianguan northeast in sichuan

Rock(sandstone, ash stone) in fei xian guan northeast Sichuan was used as rock sample,Experimental research on elasticity wave in room was done by testing technology of sound wave. The speed of elasticity wave and the dynamical elasticity parameter is calculated by the experiment. After the experiment, the physics mechanic character of rock is analyzed by experiment data.     

Analyses of Annual Running Conditions for Ventilation System in Residences in Hot Summer and Cold Winter Regions

Based on the definitions of air conditioning period, dehumidifying period and heating period, this paper puts forward the exchanging conditions and psychrometric process of ventilation system in residences. Because of the remarkable humid climate in hot summer and cold winter regions, the ventilation dehumidification becomes a more important part of the air treatment system. In order to improve the indoor thermal environment quality, new strategies must be founded to control both temperature and humidity of ventilation system.     

Analysis of Failure Behaviors in Glass under Shock Loading

The failure wave phenomena in glass media under shock loading are analyzed. The propagating mechanism and dynamic characteristics of failure wave and the property of failure layer are revealed. On the basis of experimental analysis, a damage accumulating model determinated by partial stress impulse is proposed, which describes the phenomenon of failure delay in materials being done with the Heaviside function. The propagating procedure, the evolution characters of transverse stress and longitudinal compression strain in failure layer are simulated. Furthermore a phenomenon is revealed that the failure wave velocity decreases after reflection of rarefaction wave at the boundary of failure layer.     

The study on Harmonic Wave Compensation Method of a SCR Regulating-Speed Control Filter Device in a Serosystem

We have studied the method of eliminating the harmonic wave of SCR regulating-speed device a servosystem and increasing its power supply unit' s loading ability when its current is large. Compared with other methods by experiment,we think the compensation method using micro-computer to auto control harmonic wave filter compensation is simpler and more practical.