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71.
This paper investigates the transverse and planar vibration characteristics of two-layered piezoceramic disks for traction-free boundary conditions by theoretical analysis, finite element numerical calculation, and experimental measurements. Amplitude-fluctuation electronic speckle pattern interferometry (AF-ESPI), laser Doppler vibrometer (LDV), and impedance analysis were used to perform measurements and verify the theoretical solutions for extensional, tangential, and transverse vibrations. The poling direction of piezoelectric elements determines whether they are denoted as either of series- or parallel-type. This study observed that the resonant frequencies and mode shapes of the series- and parallel-type piezoceramic disks present different dynamic characteristics in resonance. Planar and transverse vibrations are coupled in series-type piezoceramic disks and uncoupled in those of parallel-type. Good agreements of dynamic characteristics determined by theoretical analysis, experimental measurements, and numerical calculation are presented for series- and parallel-type piezoceramic disks. 相似文献
72.
Zebib.Y. Nuru C.J. Arendse R. Nemutudi O. Nemraoui M. Maaza 《Physica B: Condensed Matter》2012,407(10):1634-1637
Nano-phased structures based on metal–dielectric composites, also called cermets (ceramic–metal), are considered among the most effective spectral selective solar absorbers. For high temperature applications (stable up to 650 °C) noble metal nanoparticles and refractory oxide host matrices are ideal as per their high temperature chemical inertness and stability: Pt/Al2O3 cermet nano-composites are a representative family. This contribution reports on the optical properties of Pt/Al2O3 cermet nano-composites deposited in a multilayered tandem structure. The radio-frequency sputtering optimized Pt/Al2O3 solar absorbers consist of stainless steel substrate/ Mo coating layer/ Pt–Al2O3/ protective Al2O3 layer and stainless steel substrate/ Mo coating layer /Pt–Al2O3 for different composition and thickness of the Pt–Al2O3 cermet coatings. The microstructure, morphology, theoretical modeling and optical properties of the coatings were analyzed by the x-ray diffraction, atomic force, microscopy, effective medium approximation and UV–vis specular and diffuse reflectance. 相似文献
73.
Isao Kagomiya Yusuke Hayashi Ken-ichi Kakimoto Kazuyoshi Kobayashi 《Journal of magnetism and magnetic materials》2012
The particulate and the multilayer CoFe2O4(CFO)–BaTiO3(BT) composites were prepared by the conventional solid state reaction method and the tape casting method, respectively. Both the prepared composites were simultaneously ferroelectric and ferromagnetic at room temperature. For the multilayer composite sample, a piezoelectric resonance frequency remarkably depended on the applied DC magnetic field, while no remarkable magnetic field dependence was observed for the particulate composite samples. An uniform magnetostriction of the CFO phase in the multilayer composite contributes to piezoelectric effect of the BT phases, resulting in the modulation of the piezoelectric resonance frequency. 相似文献
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It was well known that protein interacted strongly with natural and syntheticpolyelectrolytes mainly through electrostatic forces to form a complex. These forces maylead to the formation of amorphous precipitates, protein assembly by the alternatelyelectrostatic adsorption immobilize protein can be formed a multilayer filml'2. Bypreparation of anisotropic protein layer and precise control of the distance of active layer,sequential reaction and vectorial transfer of electron and energy become f… 相似文献
78.
在简要介绍ALC/GPC 15 0c高温凝胶渗透色谱仪的基础上 ,选择了旋转空气分配阀、泵的控制电路、示差折光检测器、信号测量、微机控制和电源等关键部件所产生的十个有代表性的、已排除的故障实例进行深入分析研究 ,提出了排除故障的思路和办法 相似文献
79.
JIANGMin ZHANGHong WANGEn-bo KANGZhen-hui LIANSuo-yuan XULin WUAi-guo LIZhuang 《高等学校化学研究》2004,20(1):15-19
The ultrathin multilayer films of rare-earth-containing polyoxometalate cluster K17[Eu(P2Mo17O61)2](EuPMo) and poly(allylamine hydrochloride) (PAH) have been prepared by the Layer-by-Layer(LbL) selfassembly method. The photoluminescent behavior of the films investigated at room temperature shows the Eu^3 characteristic emission pattern of ^5Do→^7FJ(J=1—4). The occurrence of the photoluminescent activity confirms the potential of creating luminescent multilayer films with polyoxometalates (POMs). 相似文献
80.
利用神光Ⅱ上激光与等离子体相互作用得到的软X光,建立了基于多层镜的四通道软X光单色器系统。研究了光源的性能,测量了光源强度、单色器系统稳定性、相应通道的一致性。研究表明,采用多层镜作为脉冲光源的分光元件,可以得到具有较好单色性的强脉冲软X 光标定源。光源的光子能量为253 eV和820 eV,两能道的光源强度分别为1.8×1019 photon/(s·cm2)和3.2×1019 photon/(s·cm2)。在该标定源上可以实现XRD、平面镜、多层镜、透射光栅和滤片的标定。 相似文献