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161.
Hong C. Shen Author Vitae 《Tetrahedron》2009,65(20):3931-1252
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Jingqi Guan Ying Yang Bo Liu Yuanyuan Ma Xiaofang Yu Jing Liu Qiubin Kan 《Reaction Kinetics and Catalysis Letters》2008,95(2):313-320
MoV0.3Te0.17 and MoV0.3Te0.17Nb0.12 catalysts were prepared by a hydrothermal synthesis route and tested for the oxidation of isobutane and isobutene. Characterization
results showed that the structure and property of Mo-V-Te-based catalysts are relatively different depending on the presence
of the Nb element. Catalytic tests showed that the selectivity of methacrolein can comparatively be improved by the addition
of Nb into the MoV0.3Te0.17 catalyst for the selective oxidation of isobutane. 相似文献
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The phenomenon of supergain for a circular array and its robust beamforming are presented. The coplanar superdirective array gain of the circular array, although it is not so extreme as an endfire line array, outperforms a lot over that of a conventional delay-and-sum beamformer in isotropic noise fields when the inter-element spacings are much smaller than one-half wavelength. However, optimum beamforming algorithms can be extremely sensitive to slight errors in array characteristics. The performance are known to degrade significantly if some of underlying assumptions on the sensor array is violated. Therefore, white noise gain constraint is used to improve the robustness of the supergain beamformer against random errors. We show that the design of the weight vector of robust supergain beamformer can be reformulated as a form of second-order cone programming and resolved efficiently via the well-established interior point method. Results of computer simulation for a 24-element circular array confirm satisfactory performance of the approach proposed in this paper. 相似文献
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Two new furostanol glycosides, torvosides O (1) and P (2), were isolated from leaves of Solanum torvum. Their structures were completely and unambiguously assigned by one‐ and two‐dimensional NMR techniques (1H NMR, 13C NMR, TOCSY, HSQC, ROESY and HMBC), ESI‐MS spectrometry and chemical methods. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献