液相检测的Love波传感器的制作与研究

在分析Love波传感器液相质量检测机理的基础上,设计并制作了以36°YXLiTaO3为基底,交联处理的聚甲基丙烯酸甲酯(PMMA)为波导层的Love波器件。器件的中心频率为118 MHz,插损为-16 dB。通过建立电镀实验模型,实时的检测了在液相中吸附于阴极薄膜上铜的质量,并测试到传感器的灵敏度为-0.387 cm2/g。分析了灵敏度实验值与理论值的差别,进一步提出了改进方案与措施。     

成层介质中Love波相速度频散曲线计算的比较

根据基岩弹性半空间上水平成层覆盖土层Love波相速度频散曲线计算方法 ,编写了Fortran程序 ,计算了日本的两个实际工程场地的Love波频曲线 ,并与文献 [4 ]的计算结果进行了对比 ,验证了本文所编写的程序。     

Aqueous Chemical Solution Deposition of Ferroelectric Thin Films

Thin films of various ferroelectric multimetal oxides such as (Bi 1 m x La x ) 4 Ti 3 O 12 (BLT), SrBi 2 Ta 2 O 9 (SBT) and PbZr 1 m x Ti x O 3 (PZT) have been prepared by an entirely aqueous chemical solution deposition (CSD) route. Two critical issues related with aqueous CSD have hereby been worked out: in spite of the high degree of hydrolysis of tetra- and pentavalent metal ions (Ti 4+ , Zr 4+ , Ta 5+ , ) we managed to prepare stable aqueous precursor solutions by chemical modification of these individual metals, avoiding phase segregation. Another problem related with aqueous CSD is the wetting of the substrate (both metallic and metal oxide) by the aqueous solution. The hydrophilicity of the substrates is optimized by a chemical treatment of the substrate surface. In this manner, the addition of wetting agents, hence possibly disturbing the gelation reactions, is avoided. In order to study the gelation, decomposition, crystalization and the morphology of the thin films, various characterization techniques ((cryo-)TEM, SEM, EDX, TGA-MS/FTIR, HT-DRIFT, HT-XRD, ) are used.     

现代超级计算机与超大规模集成电路产业链自动化将形成BACNet+HBES+CC-Links+eFactory高技术新市场的分析——3.地震波的灾前分量实时分析-判定-触发核电安全控制Gbps FCS

本文基于中国科学院与国外的卫星遥感数据,用地震波理论,分析中国与英国地震台分别测到的2006印尼与2011日本大地震波波形,为工程研发提供科学基础。由此建议以Gbps高速CC-LinkIE,在大地震灾前的秒级时段内,自动对地震波的灾前非破坏性先导分量,进行实时时域数字化分析-判选-触发,在灾前关闭连锁核反应,同时启动核电厂自动测控DCS系统中各级FCS现场总线中的SIL4安全措施系统。     

基于ZnO/AlN/金刚石温补结构的研究

使用COMSOL软件对ZnO/AlN/金刚石温度补偿结构进行建模分析,计算了该结构Love波模式0和模式1的频率温度系数(TCF)、声速(v)和机电耦合系数(k~2),且讨论了ZnO薄膜厚度h_(ZnO)和AlN薄膜厚度h_(AlN)对这些参数的影响。结果表明,当h_(ZnO)=1μm,h_(AlN)=1.88μm时,温度补偿结构Love波模式1的TCF=0,v=9 208 m/s,k~( 2)=3.84%,说明这种温度补偿结构能应用在高频和温度补偿声表面波器件中。     

界面缺陷对压电薄层复合结构中Love波的影响

基于剪切弹簧模型,建立考虑界面缺陷情形的弹性基底上覆盖压电薄层的复合结构中Love波的频散方程,并研究界面缺陷对Love波传播特性的影响,给出铝基底上覆盖PZT4压电薄层复合结构中Love波的频散曲线.数值结果表明:(1)对于长波情形,不同缺陷程度复合结构的Love波一阶模态的相速度均趋于弹性基底层的剪切波波速,而对于短波情形,则趋于压电薄层的Bleustein-Gulyaev(B-G)波波速;(2)界面缺陷的存在总是降低该复合结构内Love波的相速度,在一些特殊频率范围,Love波的相速度对界面缺陷非常敏感;(3)界面缺陷对压电层内的机械位移模态和电势模态有显著影响,且影响最大区域出现在界面附近.     

论劳伦斯小说《恋爱中的女人》的艺术特色

解析了英国现代主义大师戴·赫·劳伦斯的代表作小说《恋爱中的女人》的艺术特色,从作家的心理表现手法和象征主义的手段两个角度探讨了小说结构的独创性,评析了作家运用这两种表现手段的个人特点.     

An experimental study of Love-wave acoustic sensors operating in liquids

It has been shown that properly designed Love-wave acoustic sensors are very promising for sensing in gaseous and liquid environments because of their high sensitivity. Since Love-wave devices do not incur a radiative loss when used in a liquid, they have many potential applications in biosensing. We have successfully manufactured a range of 40 μm wavelength Love-wave devices based on SiO₂/ST-quartz, with the SiO₂ thickness ranging from 0 to 7.3 μm. The relationship of the mass-loading sensitivity to the thickness of the SiO₂ layer has been obtained experimentally. High sensitivity (≥ 300 cm⁻² g⁻¹) is achieved at an SiO₂ thickness between 3.5 and 6.5 μm. The Love-wave oscillators have operated efficiently in various liquids with excellent stability and low noise. In this paper, we report the experimental results for the devices operating in various liquids. The mass sensitivity, insertion loss, oscillation frequency stability, noise level, liquid viscous loading and acoustoelectric coupling have been studied. The influence of the thickness of the SiO₂ layer on some of these properties has also been investigated.     

Love wave hydrogen sensors based on ZnO nanorod film/36°YX-LiTaO3 substrate structures operated at room temperature

Love wave hydrogen sensors based on ZnO nanorod layers deposited on 36°YX-LiTaO₃ substrates have been studied. The ZnO nanorod layers are prepared by two steps: first, the seed layers, as well the guiding layers of the Love wave devices, are deposited by RF magnetron sputtering; second, the nanostructural layers, as well the sensing layers of the sensors, are grown by hydrothermal synthesis. Two kinds of ZnO layers have been analyzed by XRD, SEM and XPS. The XRD shows that both ZnO layers have (0 0 2) oriented wurtzite structures. The SEM results reveal that the morphologies of the deposited ZnO seed layers are continuous and compact, while the hydrothermal treated layers are with nanorods almost perpendicular to the substrate surfaces. Finally, the hydrogen sensing responses of the Love wave sensors activated by Pt catalysts are measured for various concentrations of hydrogen in synthetic air at room temperature. The results show that the sensors have high sensitivity and repeatability as the nanorod layers are optimized, such as the frequency shift 8 kHz toward 0.04% of H₂ in synthetic air is obtained while the height of the nanorod layer is about 2.1 μm and the central frequency of the sensor is about 125.5 MHz. The XPS analyses of the sensitive layers show that there are oxygen vacancies in the layers, so the oxygen vacancy model is used to explain the hydrogen sensing mechanism of the Love wave sensors.     

利用Love波弥散特性对有关土参数的反分析

本文利用阻尼最小二乘法推导了Love面波法反分析成层地基中土的有关参数的公式。文献[1]利用有限元与半无限元相结合的方法已能精确有效地求解成层地基中Love面波的理论弥散曲线。在此基础上,本文给出了利用实测的Love面波的弥散曲线反分析土层参数的方法,并编制了相应的计算机程序。最后,通过计算实例验证了本文方法的可靠性和实用性。