热声驱动系统中的压力测量

介绍了自制的用于热声驱动脉管制冷装置的计算机压力波数据采集系统。该系统由硅压电压力传感器、数据采集卡、PC机和基于 Labview软件的图形化用户界面 GUI( Graphical User In-terface)组成。试验证明 ,它具有结构简单、高效精确、操作简便等特点 ,在捕捉被测系统内的动态压力变化方面具有优势 ,不但能很好地满足热声驱动器的压力测量要求 ,而且亦可移植到任何类似的测量气体压力的场合     

影响酸奶质量的因素及控制试验

酸奶的质量与风味，组织状态，口感有关。本文从原料乳的预处理，均质，热处理，发酵剂的选择，接种置，发酵温度与时间等因素讨论对产品质量的影响。     

Residual stress profiling of an aluminum alloy by laser ultrasonics

A residual-stress profile along the thickness of an aluminum alloy sheet is determined by laser-ultrasonic technique. Surface acoustic waves are generated by a Nd:YAG pulse laser and detected by a Heterodyne interferometer on a lateral free surface of the sheet. The distribution of residual stress is determined by measuring the relative variation of the wavevelocities at different location of the sample along its thickness. This technique is validated by three different residual stress profiles obtained experimentally.     

用声级计和PC机测定声室T60的一种方法

介绍了用常规仪器设备声级计和PC机测定声室混响时间T60的一种简便方法，实际测量结果表明，该方法可以满足一般声室T60的估算要求。