高性能低频交变磁场传感器的研究与制作

详细介绍了利用一种新型材料(铁基纳米晶合金)作为磁芯的高性能低频交变磁场传感器的工作原理、制作及测试结果.测试结果表明利用此新型材料作为磁芯制作的传感器,是一种较理想的高性能的传感器,在低频交变磁场探测的众多领域中具有广泛应用.     

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.     

Ionic composition of rat airway surface liquid determined by X-ray microanalysis

The thin layer of liquid that lines the conducting airway epithelium, the airway surface liquid (ASL), is important for mucociliary clearance. Altered ionic composition and/ or volume of the ASL play a major role in the pathology of airway diseases such as cystic fibrosis. Since the ASL is a thin layer, it has been difficult to exactly determine its composition. The present paper describes two techniques that have been developed and used to study ASL composition: X-ray microanalysis of frozen hydrated rat trachea, and an ion-exchange (dextran) bead method, where dextran beads were placed on the airway epithelium to equilibrate with the ASL; the beads were then collected under silicone oil, dried and analyzed by X-ray microanalysis. The results from both frozen-hydrated specimens and from the dextran beads showed that ASL from rat trachea is hypotonic. Concentrations of Na, P, S, and K were higher in the frozen-hydrated ASL, in which mainly the mucus layer is analyzed, compared with the dextran bead method, in which mainly the periciliary liquid is sampled. Also the composition of rat nasal fluid was investigated by the dextran bead method. This fluid was somewhat hypertonic because of a high K concentration. The ionic composition of the nasal and tracheal fluid can be manipulated by cholinergic or alpha- or beta-adrenergic stimulation. Collecting ASL with dextran beads did not disturb the integrity of the airway epithelium. The ionic composition of the collected beads remained stable for several days during storage in silicone oil. It is concluded that X-ray microanalysis is a suitable method to determine the ionic composition of ASL.     

Formation of a resting form of Bacillus cereus and Micrococcus luteus

Under certain cultivation conditions, the bacteria Bacillus cereus and Micrococcus luteus form cystlike refractive cells (up to 60% of the total number) that retain viability over a long time, are metabolically inactive and thermotolerant and possess specific ultrastructure. These properties allow them to be attributed to a new type of resting forms of microorganisms.