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141.
Akhlesh Lakhtakia Martin W. McCall Werner S. Weiglhofer 《AEUE-International Journal of Electronics and Communications》2002,56(6):407-410
This brief overview covers a rapidly occurring development in the area of microwave composite materials: isotropic dielectric–magnetic mediums wherein the phase velocity vector and the time–averaged Poynting vector are oppositely directed. Such materials have also been inappropriately designated as left–handed materials. Ramifications for aberration–free lenses, homogenization approaches, and complex mediums are also presented. 相似文献
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A novel current source inverter system interconnected to the single‐phase grid is proposed. It has the same construction as the conventional three‐phase current source inverter that is interconnected to the single‐phase three‐wire distribution system. Though the proposed circuit has no output transformer, it can be equivalently performed as the single‐phase double cascade inverter by diverting the pole transformer in the utility system. By controlling the appropriate scheme, the output currents can be obtained as the five‐level waveforms and their distortions can be decreased sufficiently. It is applied to the interactive electric energy storage system with batteries and the basic discharging characteristics are discussed experimentally. © 2004 Wiley Periodicals, Inc. Electr Eng Jpn, 150(2): 50–61, 2005; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.10380 相似文献
145.
A 0.3% Au/Al2O3 catalyst prepared by the incipient wetness (IW) method was investigated in the continuous-flow liquid-phase glucose oxidation. Therefore, a continuous stirred tank reactor (CSTR) system equipped with an ultrasonic separator was used. The continuous-flow glucose oxidation was carried out at 40 °C, pH 9 and 1 bar oxygen partial pressure. Residence time and glucose concentration were varied. The IW gold catalyst showed very high activity and selectivity to gluconic acid within its 110 days of operation and, thus, an excellent long-term stability. Even after severe microbial contaminations of the catalyst, its activity could be completely restored by in situ regeneration with 2-propanol. 相似文献
146.
Loschky Lester C.; Sethi Amit; Simons Daniel J.; Pydimarri Tejaswi N.; Ochs Daniel; Corbeille Jeremy L. 《Canadian Metallurgical Quarterly》2007,33(6):1431
People can recognize the meaning or gist of a scene from a single glance, and a few recent studies have begun to examine the sorts of information that contribute to scene gist recognition. The authors of the present study used visual masking coupled with image manipulations (randomizing phase while maintaining the Fourier amplitude spectrum; random image structure evolution [RISE]; J. Sadr & P. Sinha, 2004) to explore whether and when unlocalized Fourier amplitude information contributes to gist perception. In 4 experiments, the authors found that differences between scene categories in the Fourier amplitude spectrum are insufficient for gist recognition or gist masking. Whereas the global 1/f spatial frequency amplitude spectra of scenes plays a role in gist masking, local phase information is necessary for gist recognition and for the strongest gist masking. Moreover, the ability to recognize the gist of a target image was influenced by mask recognizability, suggesting that conceptual masking occurs even at the earliest stages of scene processing. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
147.
K. Doverspike L. B. Rowland D. K. Gaskill J. A. Freitas 《Journal of Electronic Materials》1995,24(4):269-273
This paper presents a comparative study of the properties of GaN grown by organometallic vapor phase epitaxy, using both a
GaN and A1N buffer layer, as a function of sapphire orientation (c-plane vs a-plane). Results are presented for varying the
thickness of the buffer layer, varying the growth temperature of the GaN film, and also varying the ammonia/trimethylgallium
mass flow ratio. The electron Hall mobilities of GaN films grown on an A1N buffer layer were, in general, higher compared
to films grown using a GaN buffer layer. In addition, growth on a-plane sapphire resulted in higher quality films (over a
wider range of buffer thicknesses) than growth on c-plane sapphire. The room temperature electron mobilities were also found
to be dependent on, not only the growth temperature, but also the ammonia/trimethylgallium mass flow ratio. 相似文献
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Ti_3AlPHASEPRECIPITATIONDURINGVIBRATIONFATIGUINGFORATITANIUMALLOY¥TaoChunhu;ZhangShaoqing;YanMinggao(InstituteofAeronauticalM?.. 相似文献
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