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161.
The luminescence and conduction currents of a doubly-insulated thin-film electroluminescent device were studied under various excitation conditions. The conduction current waveform was calculated numerically from the luminescence waveform. It was composed of two components: a fast transient component jfc, which rises and decays rapidly when a pulse is applied, and a dc-like component jdc, which maintains a constant level during the duration of pulse. The ratio of these components varied considerably with applied voltage. Both the slow response of luminescence to voltage change and the change in jfc when the excitation conditions were changed from repetitive pulses to a single pulse suggest an accumulation of charges inside the electroluminescence layer. This accumulation causes a space charge effect which explains the dominance of jfc in the high-brightness region. The fact that luminescence intensity in this region is not related to the amplitude of individual pulses, but rather to the average amplitude of the pulse train also indicates that the space-charge-induced internal electric field is the main factor in accelerating the carriers which excite the luminescence centers. It was found that the two conduction current components showed similar characteristics in singly-insulated devices. 相似文献
162.
E. Amaldi E. Coccia C. Cosmelli Y. Ogawa G. Pizzella P. Rapagnani F. Ricci P. Bonifazi M. G. Castellano G. Vannaroni F. Bronzini P. Carelli V. Foglietti G. Cavallari R. Habel I. Modena G. V. Pallottino 《Il Nuovo Cimento C》1984,7(3):338-354
Summary We report on the cooling at liquid-helium temperature of our 2270 kg 5056 Al bar at CERN. The liquid-helium container had
been filled up to 1500 liters ensuring to keep the antenna cold for more than one month. The antenna is equipped with a resonant
capacitive transducer operating at constant electrical charge with a FET low-noise amplifier. The transducer is tuned to the
antenna within less than I Hz and the two normal-mode frequencies are ν−=908.160 Hz and ν+=924.234 Hz with an applied electrical field in the transducer of 106 V/m. The corresponding overall merit factors areQ
−=5.20·106 andQ
+=7.25·106. The transducer has been tested up to an electrical field of 6·106 V/m: in this condition we have βQ≈104. The antenna has been in operation for several weeks giving, for the Brownian noise, values in agreement with the calculated
values. We report also on the results of tests performed on a DC SQUID, whose input was connected to a commercial capacitor
via a transformer with turn ratio of 1000.
Supported in part by Japan Society for the Promotion of Science. 相似文献
163.
Keiichi Moriya Shigekazu Nakagawa Shinichi Yano Meisetsu Kajiwara 《Liquid crystals》1995,18(6):919-921
(S)-Hexakis(4-(4'-(6-methyl)octyloxy)biphenoxy)cyclotriphosphazene (SMOCP) was synthesized in a search for new ferroelectric liquid crystalline compounds. We found an enantiotropic ferroelectric smectic C* phase between 419 and 441 K in SMOCP by using polarizing microscopy and DSC measurements. The spontaneous polarization was estimated to be -130.5 μCm-2 at 437.6 K, several times larger than that of DOBAMBC ((S)-2-methylbutyl 4-(4'-decyloxybenzylidene)aminocinnamate. 相似文献
164.
Dimethylaluminiun chloride has been found to cleave THP ethers selectively without any removal of t-butyldimethylsilyl ethers 相似文献
165.
166.
T. Idehara I. Ogawa Y. Shimizu T. Tatsukawa 《International Journal of Infrared and Millimeter Waves》1998,19(6):803-816
Higher harmonic operation of gyrotrons is necessary to obtain high frequencies. Some gyrotrons included in the Gyrotron FU series developed at Fukui University have achieved operation at the third and even fourth harmonics of the electron cyclotron frequency. The output lies in the millimeter to submillimeter wavelength range and the output powers are several watts to several tens of watts. In this paper, the gyrotrons and the conditions under which they operate are described in detail. 相似文献
167.
168.
Extraction chromatography using macroreticular ethylstyrene-divinylbenzene beads impregnated with monothiodibenzoylmethane (SBB) solution has been investigated. Of the solvents used as the stationary phase, heptan-1-ol showed the highest rate of metal extraction, and loading with 0.5 ml of the solvent per g of resin was found to be the optimum. A column packed with such loaded beads can be used for the separation of nickel(II), iron(III) and cobalt(II). 相似文献
169.
170.
Tohru Ogawa 《Zeitschrift für Physik B Condensed Matter》1977,28(2):73-85
Although the five-fold symmetry conflicts with the crystalline long range order, it can appear in some finite systems. In order to search for such possibility in the microclusters in the small size limit and to clarify the roles of the electrons in the morphology, the electronic states are studied in the tight binding scheme. The single electron spectra coming from thes- andp-atomic orbitals are derived for three types of the 13-atom clusters; with the fcc-like configuration, the hcp-like and the icosahedral. If the transfer integral between two surface atoms is put equal to that between the central and a surface atom in the icosahedral case, this configuration has the lowest total electronic energy in many cases studied, but not always. The fact that a surface atom has larger number of neighbours in the icosahedral configuration is surely of great advantage. It, however, is not almighty in the quantum case.On leave from Department of Physics, Faculty of Science, Kyoto University, Kyoto 606, Japan. A part of this work was done there 相似文献