浅议物理实验教学环节改革

为进一步提高大学物理实验的教学质量，本文就实验课的预习、操作、实验报告的撰写及考核方法进行了探讨。     

Novel quantitative non-destructive testing method for composite structures

A novel QNDT (quantitative non-destructive testing) method is developed that is combined with a phase-shifting shearing speckle and thermograph, and, it aims at the detection of faults such as cracks, voids, delamination and weak areas. The technique is immune to ambient noise and is suitable for measuring the in situ environment. Some different depth defects that would produce deformation differing from other positions could be found with shearing speckle when the sample is loaded, however, a thermograph based on the thermal resistance effect of a defect can detect only those varisized defects embedded deeply in the composite structure by measuring the surface temperature distribution. The resolution is examined for artificial delaminated defects in carbon-fiber composite structures using a phase-shifting shearing speckle and thermograph. The experimental results have demonstrated that the technique is effective for revealing defects in composite structures.     

Detection of kissing bonds by Lamb waves

Closed cracks under compressive normal stresses are difficult to detect by the conventional ultrasonic techniques. When the crack surfaces stay in very close contact with each other then the bond between the two surfaces of the crack is called a ‘kissing bond’. This is a very dangerous bond. Catastrophic failures can result if the system is subjected to crack opening normal stresses or shear stresses. When the crack surfaces are smooth then kissing bonds cannot transmit shear stress very well but can carry compressive normal stress, these bonds are called ‘slip bonds’. Conventional P-wave scans (C-scan or A-scan) are based on the assumptions that P-waves are reflected by the defective interface. However, an interface subjected to a large compressive stress cannot reflect P-waves effectively, hence these bonds remain invisible to the conventional P-wave based C-scan or A-scan techniques. In this paper it is shown that the kissing bonds can be effectively detected by some leaky Lamb mode. Theoretical and experimental results are presented to show that using the Lamb waves is an effective way of detecting kissing bonds.     

提高超声测距分辨力的分析与设计

本文分析了分辨力误差的定量关系，并以此为指导选择和设计超声发射，接收，测时等电路以及数字滤波方法，提亢超声测距的精度和分辩力。     

数字式超声成象的相干处理

本文介绍一种新的医学超声成象处理方法－相干处理。这种方法保留和利用了不同通道中信号的相干性，因此能增强图象分辩率，改进图象的质量。     

半桥逆变式功率VMOSFET超声电发生器的研制

本文介绍了一种用于超声波电火花复合加工的超声发生器，它以功率ＶＭＯＳ场效应管作开关元件，以单片集成电路ＴＬ４９４作为信号源控制核心。发在具有工作稳定可行以的特点。     

同时发射和接收纵波和横波的压电复合材料换能器

通过控制压电复合材料中压电相的分布形式，本文具有在百度模振动的１－３型压电复合材料和具有扭转模振动的拼接２－２型压电复合材料组合在一起，构成一种混俣模式压电材料，并测试了这种压电材料晶片的性能参数，使用这种晶片作的换能器可以根据使用者的要求，单独产生纵波或横波，也可同时产生这两种波。     

红外气体浓度测试仪设计

在实验室条件下采用红外光谱对气体浓度进行定量分析的技术已很成熟,但是,适用野外环境条件下进行气体浓度精密测量的仪器并不多见。本文设计的仪器是文献〔３〕所述的一种便携式红外气体浓度测试仪器的改型,测量范围０－１００％,精度比文献〔３〕所述红外气体浓度测试仪器有所提高,且使用方便,工作稳定,数据可靠。     

套管井中仪器偏心对井壁超声电视图象的影响及其校正

文章研究了在套管井中仪器偏心对井壁超声电视图象的影响,提出了基于计算影响所用模型的校正方向,实验结果表明,该方法能较好地消除由于仪器偏心所引起的超声电视图象中的两条垂直黑带,明显地改善图象的质量,经对比度增强后,井壁的细节更加清楚。     

超声波辐照下N,N,N’,N’-四甲基二氨基二苯 甲烷的合成研究

本文报道了Ｎ,Ｎ,Ｎ’,Ｎ’－四甲基二氨基二苯甲烷的催化合成反应研究,讨论了超声空化场对氨基苯磺酸和阴离子表面活性剂等条件对该反应的催化作用。