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混沌腔体换能器在反向滤波弹性检测中的应用及其仿真研究 被引量:1
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作者 李义丰 Bou Matar Olivier 李宝顺 《声学学报》 EI CSCD 北大核心 2014年第4期459-466,共8页
针对传统单通道时间反转无损检测成像质量低,检测灵敏度差的问题,通过混沌腔体换能器(Chaotic Cavity Transducer:CCT)的应用,极大提高聚焦检测的能力。CCT的使用可以更好的利用介质的各经历态特性,其有效解决了单通道时间反转检测中的... 针对传统单通道时间反转无损检测成像质量低,检测灵敏度差的问题,通过混沌腔体换能器(Chaotic Cavity Transducer:CCT)的应用,极大提高聚焦检测的能力。CCT的使用可以更好的利用介质的各经历态特性,其有效解决了单通道时间反转检测中的幻影成像及边界应力增加的问题。实验过程中采用了线性调频激发信号源(Chirped Excitation:CE)及反向滤波技术(Inverse Filter:IF),他们分别能够携带更多的能量及利用更多反转信号的模态,进而有效的提高信号聚焦的质量。为了更好的理解混沌腔体换能器的特性,采用了非连续Galerkin算法对其聚焦性能进行了数值仿真和分析。数值仿真的结果及混响介质检测与成像的实现,验证了CCT与CE及IF结合应用的有效性和高效性。 展开更多
关键词 时间反转 数值仿真 线性调频 成像质量 聚焦性能 TRANSDUCER 信噪比 介质表面 自动聚焦 脉冲响应
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Oxidative dehydrogenation of propane under steady-state and transient regimes over alumina-supported catalysts prepared from mixed V_2W_4O_(19)^(4-) hexametalate precursors
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作者 Sébastien Paul Elise Berrier +1 位作者 Marcia Cristina Kaezer Frana Jean-Guillaume Eon 《Journal of Natural Gas Chemistry》 CAS CSCD 2010年第2期123-133,共11页
An integrated approach combining the development of an innovative catalyst and the research of a set of adequate operating conditions for the propane oxidative dehydrogenation (ODH) is described.The experimental set... An integrated approach combining the development of an innovative catalyst and the research of a set of adequate operating conditions for the propane oxidative dehydrogenation (ODH) is described.The experimental set-up,specially designed for steady-state and transient studies is presented.The preparation method,the characterization and the performances in steady-state and transient regimes of catalysts based on V2W4O194-Lindqvist isopolyanion used as a precursor and supported on alumina are reported.The influence of the preparation method of the catalyst and the role of water in the feed gas are more particularly discussed. 展开更多
关键词 PROPANE oxidative dehydrogenation (ODH) transient regime pulsed reactor Lindqvist isopolyanion in-situ Raman
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Keggin-type H_4PVMo_(11)O_(40)-based catalysts for the isobutane selective oxidation 被引量:1
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作者 PAUL Sébastien SULTAN Manzoor BORDES-RICHARD Elisabeth 《Science China Chemistry》 SCIE EI CAS 2010年第9期2039-2046,共8页
Cesium heteropolysalts Cs3PMo12O40 and HCs3PVMo11O40 were synthesized by modifying the preparation conditions in order to get materials with a much higher surface area than the original Keggin-type heteropolyacids(H3P... Cesium heteropolysalts Cs3PMo12O40 and HCs3PVMo11O40 were synthesized by modifying the preparation conditions in order to get materials with a much higher surface area than the original Keggin-type heteropolyacids(H3PMo12O40 and H4PVMo11O40).These solids were used as carriers for the dispersion of H4PVMo11O40 heteropolyacid by the incipient wetness impregnation technique.The textural and structural properties of supports and catalysts were examined by scanning electron microscopy,N2 adsorption-desorption isotherms and Raman spectroscopy.The supported catalysts were studied before and after red/ox pretreatments by X-ray photoelectron spectroscopy,which showed that both the surface composition and oxidized to reduced species ratio depend on the used carrier.The catalytic performances of these novel supported catalysts in the selective oxidation of isobutane to methacrylic acid and methacrolein were studied.The best catalytic properties were obtained when H4PVMo11O40 was supported on HCs3PVMo11O40.The isobutane conversion and yield of the desired oxygenates increased along the unsupported H4PVMo11O40【H4PVMo11O40/Cs3PMo12O40【H4PVMo11O40/HCs3PVMo11O40 series. 展开更多
关键词 CESIUM heteropolysalts supports supported H4PVMo11O40 red/ox XPS ISOBUTANE selective oxidation KEGGIN-TYPE HETEROPOLYCOMPOUNDS
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