海底管道缺陷在线智能检测机器人

分析了用MFL法检测管道缺陷时缺陷漏磁信号分辨率的特征,设计计算机控制的管道漏磁场分布测试系统检测、分析管道内漏磁场,优化设计用于小管径、厚管壁海底管道(ф273×12.7)缺陷检测的磁铁节,在此基础上设计制造了海底管道缺陷在线智能检测机器人,实验验证了机器人对人工模拟缺陷的检测能力.     

基于二阶系统的动态汽车衡称重方法及应用

采用离散化二阶系统的分析方法实现了动态汽车衡的称重测量.从称重过程的力学模型分析入手,推导出系统传递函数关系并作离散化处理,采用最小二乘法估计系统的模型参数,由称重系统的测量值推算车辆的实际重量.将此方法应用于某公路动态汽车衡的开发,安装路试表明,动态测量与静态称重的吻合度控制于1.5%以内.     

嵌入式光纤光栅传感器应力传递规律研究

从力学的观点,将被测对象混凝土构件和埋入其中的光纤光栅传感器看成是一种复合材料或复合体,首次将剪滞法理论(shear lag theory)应用于分析光栅传感器埋入混凝土构件时的应力传递规律,得到了光栅传感器的应力传递公式和应力传递系数.利用得到的光栅传感器的应力传递公式,计算了混凝土实验构件的应力变化情况,实验证明,理论计算结果和实测数据基本吻合.     

半导体温度传感器的应用研究

结构温度场的监测是结构健康监测的重要内容,然而对于混凝土结构内部的温度场监测,目前国内尚无理想的温度传感器.结合项目研究,开发了一种内埋式式半导体温度传感器.文中介绍了半导体温度传感器的测温工作原理,以及由ICL7136构成的温度测试仪的测试电路,并对具体型号的晶体管进行了温度灵敏度离散性测试,给出了克服晶体管温度灵敏度离散性的测试方法.实体测试表明,该温度传感器具有优异的性能,可以用于混凝土结构内部温度场的测试.     

Rod plateaux during dark adaptation in Sorsby's fundus dystrophy and vitamin A deficiency

PURPOSE: To investigate the transitory plateaux observed during dark adaptation after partial bleaches in Sorsby's fundus dystrophy (SFD) and in systemic vitamin A deficiency (VAD). METHODS: Psychophysical dark adaptation functions were measured after bleaching exposures isomerizing from 2% to 99% of the rhodopsin. Narrow-band stimuli of 1.7 degrees diameter and 200 msec duration were presented at an eccentricity of 30 degrees. RESULTS: After a full bleach, the patients showed typical dark adaptation abnormalities reported for these diseases. The cone recovery was slowed, and the time to the rod-cone break was delayed; the final phase of rod recovery was also slowed but led to a normal final rod threshold. After partial bleaches, short wavelength stimuli produced a biphasic recovery function, with an initial rapid component and plateau, followed by a subsequent break-off and eventual return to prebleach thresholds. Action spectra obtained during the plateaux were consistent with thresholds for shorter wavelength stimuli mediated by rods and thresholds for longer wavelength stimuli mediated by cones. In the patient with VAD, vitamin A supplementation led to accelerated recovery and disappearance of the transitory rod plateaux. CONCLUSIONS: The biphasic dark adaptation functions resulting from fractional bleaches in SFD and VAD appear superficially similar to the classic biphasic adaptation functions obtained with full bleaches. However, thresholds during the plateaux are lower than the cone threshold, and action spectra indicate rod mediation. These transitory rod plateaux may increase our understanding of the normal visual cycle and its perturbation in retinal disease.