SAW氢传感器的有限元仿真与分析

介绍了声表面波延迟线型氢传感器的有限元模型,并在ANSYS8.0平台上对此进行了仿真。压电基底采用Y-X切铌酸锂(LiNbO3),敏感薄膜为金属钯膜。通过比较钯膜吸收氢气前后输出端电压的变化,得出了钯膜的不同参数对系统输出的影响,钯膜的弹性模量变小使输出电压的幅值增大,延迟时间增长;密度变小使输出电压的幅值变小,延迟时间略有缩短。分析结果为改进敏感薄膜的性能提供了有益的借鉴。     

SAW传感器

本文主要阐述了SAW传感器的原理、分类及其特点。由于SAW传感器具有非接触、快速、无电源、抗干扰、易编码、保密性好、成本低等优点,目前已广泛应用于许多领域。本文详细地介绍了几款具有代表性的应用。     

换能器间距对柔性声表面波器件性能的影响

首先基于PEI基板磁控溅射ZnO薄膜,再在薄膜上的两端制备叉指电极,探讨了不同的叉指间距对这种柔性器件的影响。研究发现,当两个叉指式换能器(IDT)之间的距离增加时,谐振器的传输幅度会显著衰减。为了制造具有良好传输性能的器件,IDT之间的间距应小于声波波长的40倍。这些结果可以为柔性声波器件的发展提供参考。     

基于耦合模理论的P矩阵模型

本文根据耦合模理论推出了P矩阵模型新的表示形式,并验证了该表示形式在分析双向对称一致IDT和反射器方面的适用性和精确性．应用P矩阵方法分析IDT的输入导蚋和一款SAW传感器的插损,结果显示该传感器设计具有优良的插损性能．     

X100管线钢埋弧焊焊接性能研究

X100管线钢屈服强度在690MPa以上,为了实现钢管埋弧焊缝的高强度高韧性匹配,研制了与X100管线钢相匹配的WS01焊丝,该焊丝匹配大西洋CHF105焊剂,焊接接头抗拉强度810MPa,20℃冲击功,焊缝的弯曲、硬度实验结果均达到AP15L钢管标准要求。     

加性加权法在确定软件需求优先级中的应用

确定需求优先级是需求管理中至关重要的工作，首先介绍常用需求优先级的确定方法，在此基础上提出了需求优先级确定中定性和定量相结合的过程模型，其次运用加性加权的算法结合一企业实际ERP系统开发案例，详细讨论了该系统需求优先级确定的过程和方法。最后此方法的应用及相关问题进行了总结。     

SAW reflection and scattering by electrodes

INTRODUCTION Electrodes or grooves in the path of surface acoustic wave (SAW) propagation give rise to SAW reflection and cause SAW scattering into bulk acous- tic wave. This is a fundamental SAW problem on which had been conducted many studies. It is espe- cially important for designing SAW radio frequency identification tags (RFID). Global SAW Tag (GST) (Hartmann, 2004) has many advantages over tradi- tional SAW RFID, but requires accurate knowledge of the reflectivity and …     

Research progress in SAW filter banks

INTRODUCTION SAW (Surface Acoustic Wave) filter bank is a single input, single or multi-output device consisting of multi-SAW-filters, input interconnection network or switch circuits, and can be divided into two cate- gories: channelizer (multi-output) and switchable (programmable, single output). The former is mainly used in military channelized receiver for spectrum analysis; the latter has wide application in frequency synthesizer and frequency-hopping radar and com- munication syst…     

基于可变波形SAW焊缝成形质量研究

通过对比试验研究了直流、交流方波波形参数(频率、平衡和电压偏移)对埋弧焊焊接效率的影响。结果表明,熔深随着频率的增大而减小,随着平衡和电压偏移的增大而增大?熔敷效率随着平衡和电压偏移的增大而减小。进一步试验证明:直流、交流并用有利于提高焊接生产效率。该研究成果为实际工业应用中埋弧焊成形质量提供了理论依据。     

PRO-ESPRIT 算法在声表面波标签识别中的应用

The surface acoustic wave (SAW) identification (ID)-tags have great potential for application in radio frequency identification (RFID) due to their characteristics of wireless sensing and passive operation. In the measurements based on the frequency domain sampling (FDS), to expand the range of detection and allow the system work in harsh environments, it is necessary to enhance the identification capability at low SNR. In addition, to identify the tags in real time, it is important to reduce identification time. Therefore, estimation of signal parameters based on the Procrustes rotations via the rotational invariance technique (PRO-ESPRIT) is adopted. Experimental results show that good identification capability is achieved with a relatively faster measurement speed.