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671.
672.
Video transcoding proxy for 3Gwireless mobile Internet access 总被引:2,自引:0,他引:2
Warabino A. Ota S. Morikawa D. Ohashi M. Nakamura H. Iwashita H. Watanabe F. 《Communications Magazine, IEEE》2000,38(10):66-71
Transcoding proxies for mobile World Wide Web access have been developed. In the near future, wideband mobile communication systems such as IMT-2000 will emerge, and these proxies will have to cope with a variety of media such as video. In this article we identify issues involved in viewing a video stream in a mobile computing environment; to handle these issues, we propose a video transcoding system and its control method. These mechanisms provide stable transmission of video data and comfortable video viewing on user clients by estimating the communication conditions, client device capabilities, and user preferences 相似文献
673.
A liquid model was proposed wherein crystal embryos should exist in equilibrated melts at temperatures even above the melting point or liquidus temperature and the number density of embryos should decrease as the melting temperature increases. Crystallization behavior of a Li2O·2SiO2 glass was studied. Secondary heat-treatment (600 °C for 20–60 min) of the Li2O·2SiO2 glass induced different number of crystals depending upon the melting temperature in the range 1040°–1300 °C and duration of heat-treatment t. The number density of crystals N decreased with increasing temperature of melting. The number density of pre-existing embryos was estimated from (N – t) diagram and was found consistent with what the proposed model claims. 相似文献
674.
Stability of a boron-doped diamond as an oxygen evolution electrode material was evaluated at 773 K in molten LiCl–KCl (58.5:41.5 mol%), LiCl–KCl (75:25 mol%), LiCl–CaCl2 (64:36 mol%), LiCl–NaCl–CaCl2 (52.3:13.5:34.2 mol%). In molten LiCl–KCl systems, the BDD is stable at 773 K regardless of the concentration of oxide ion and the composition of the melt. In molten LiCl–CaCl2 and LiCl–NaCl–CaCl2, the BDD electrode is less stable than in molten LiCl–KCl systems. 相似文献
675.
Yasuhiro Aruga David W. Saxey Emmanuelle A. Marquis Hisao Shishido Yuya Sumino Alfred Cerezo George D.W. Smith 《Metallurgical and Materials Transactions A》2009,40(12):2888-2900
In this study, the ultrafine structures in Cu-P and Cu-Ni-P alloys have been characterized using a three-dimensional atom
probe (3DAP) and transmission electron microscopy (TEM), and the stress relaxation behavior of these alloys has been explored.
The results show that low-temperature annealing greatly improved the stress relaxation performance, especially in the Cu-Ni-P
alloys. The presence of Ni-P clusters in the Cu-Ni-P alloys has been revealed. The overall improvement in properties has been
analyzed in terms of variations in the dislocation density and solute atom cluster density within these materials. It is shown
that clusters with small average spacing give rise to significant improvements in the stress relaxation performance, without
requiring significant change in the dislocation density. 相似文献
676.
Yuya Ishii 《Materials Letters》2008,62(19):3370-3372
A novel electrospinning process of uniaxially aligned submicron fibers was developed. The number of the fibers was precisely controlled by changing biased collector, and the diameter of the fiber was varied by post-deposition stretching process. This method realized the formation of number-controlled aligned poly[2-methoxy-5-(2′-ethyl-hexyloxy)-1,4-phenylenevinylene] (MEH-PPV)/poly(ethylene oxide) (PEO) fibers with the systematic control of the diameter ranging from micrometer to submicrometer. Significant improvement of the uniformity of the fiber diameter was also observed by the stretching process. 相似文献
677.
678.
R. Świetlik A. Łapiński M. Połomska L. Ouahab A. Ota 《Journal of Low Temperature Physics》2006,142(3-4):653-656
The monoclinic crystals of κ-phase charge-transfer salts formed by BEDT-TTF with Co(CN)6 or Fe(CN)6 anions undergo a phase transition at T = 150 K. Temperature dependences of FT-NIR Raman spectra and IR reflectance spectra
were studied. We show that the phase transition is related to a charge ordering and there exist charge fluctuations above
150 K. 相似文献
679.
Takeshi Ota Yasuhiro Murase Kenzo Maehashi Hisao Nakashima Chikara Watatani Keiichi Edamatsu Tadashi Itoh Kenichi Oto Kazuo Murase 《Journal of Electronic Materials》2001,30(5):448-452
We have investigated carrier relaxation dynamics in single CdSe/ZnSe quantum dot (QD) by time-resolved micro-photoluminescence
(PL). The discrete sharp lines, originated from individual QD states, exhibit various rise and decay time constants. The decay
times of the sharp lines from ground states and excited states are estimated to be 700≈800 psec and 400≈500 psec, respectively,
and the rise times of the ground states become longer compared with those of the excited states. There results are in contrast
to successive change of the rise and decay times observed in time-resolved macro-PL with varying the detection wave-length.
The quasi-continuum higher states with much shorter decay times are clearly observed over the discrete states of the QDs. 相似文献
680.
A lateral top-heater phase-change memory (LTH-PCM) is proposed and investigated for multilevel storage (MLS). The active layers are composed of a 50-nm-thick TiN layer as a top heater and a 150-nm-thick SbTeN layer. A number of intermediate levels, which are induced by electric currents, are exhibited in experimental results. They are distinct and very stable. The reversible switching of multilevels is successfully demonstrated in the LTH-PCM device. The MLS results from the gradual enlargement of crystalline region between electrodes by Joule heating according to our analysis. 相似文献