Author Keywords: Radiation detection; Long-lasting phosphor; Luminescence; Temperature dependence; Fade-out effect 相似文献
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1.
The present paper includes experimental and analytical data on the fracture properties of a nickel-iron superalloy, a ferromagnetic austenite, at 4 K in magnetic fields of 0 and 6 T. The tensile, notch tensile and small punch tests are employed. A finite element analysis is also performed to convert the experimentally measured load-displacement data into useful engineering information. To interpret the results we review the available theory of the influence of magnetic field on the stress intensity factor for a crack in ferromagnetic materials. 相似文献
2.
Yi Jin Chieko Toeda Takeo Kawaguchi Toshinobu Seki Kazuhiko Juni 《Drug development and industrial pharmacy》1996,22(7):653-658
Permeation of zidovudine (3'-azido-3'-deoxythymidine, AZT) and probenecid from oily bases containing an alcohol through rat skin was examined. Isopropyl myristate (IPM), as an oily vehicle, showed a penetration enhancing effect for AZT and probenecid. Ethanol, n-propanol, and n-butanol were used as additives in IPM and were examined for their own permeation and the enhancing effect on the permeation of AZT and probenecid. The skin permeation of AZT and probenecid from IPM was enhanced by addition of the alcohol in IPM. The degree of the enhancement was decreased with increasing lipophilicity of the alcohol used. me permeation rate of the drug from those systems was shown to be governed by penetration-enhancing effects of the oily base and alcohol, and the penetration of the alcohol itself through the skin. 相似文献
3.
Munehiko Kowatari Daisuke Koyama Yoshiyuki Satoh Kouichi Iinuma Shunsuke Uchida 《Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment》2002,480(2-3):431-439
The temperature dependence of luminescence from a long-lasting phosphor (LLP), SrAl2O4 : Eu2+,Dy3+, exposed to ionizing radiation has been measured to understand the LLP luminescence mechanism. Evaluation of the decay constants of the LLP exposed to -, β- or γ-rays at temperatures from 200 to 390 K showed that the decay constant is divided into four components ranging from 10−4 to 10−1 s−1 with activation energies of 0.02–0.35 eV.
Total luminous intensity from the LLP with changing irradiation temperature has its maximum value around the room temperature. Irradiation at elevated temperature (390 K) has the total luminescence pattern with monotonous decrease as temperature rises. As a result of evaluating the temperature dependence of luminescence, the luminescence mechanism is considered as follows:
4.
The light scattering from the spherulites of polyethylene terephthalate grown near the glass transition temperature has been investigated. The Hv scattering profiles can be reproduced by the sum of the ideal spherulite scattering with the distribution of spherulite radius and the isotropic scattering from randomly oriented crystallites. The ratio of optical anisotropies in the isotropic scattering to the ideal spherulite scattering is obtained by the method established to eliminate the effects of the number density of spherulites and the coefficient depending on the experimental conditions. It is found that the anisotropy ratio is almost independent of the crystallization time and of temperature above 106 °C, while it is larger at a crystallization temperature of 103 °C. The spherulitic structure is discussed in terms of the anisotropy ratio. 相似文献
5.
Recent advances in semiconductor photonic functional devices based on the nonlinearities of laser diodes (LDs) are reviewed. Because the current research is driven primarily by the needs of optical fiber communications systems, most devices are made of InGaAsP and operate at wavelengths of between 1.3 and 1.55 μm, the wavelength window in which optical fibers have their most favorable properties. Minimum loss is at 1.55 μm, and zero dispersion is at 1.3 μm. AlGaAs devices operating at around 0.85 μm have also been reported. Two types of optical bistability-absorptive and dispersive-are explained, and devices based on them are described. Switching characteristics of bistable devices are discussed. Tunable wavelength converters and filters are also examined. Applications to all-optical communication and to optical switching systems are considered. Directions for future development are indicated 相似文献
6.
Cis-1,4-polybutadiene (PB) in a 0.5% solution of a solvent mixture of dichloromethane and 1,2-dibromoethane or tetrahydrofuran was quantitatively brominated with elemental bromine at 0°C under careful exclusion of oxygen to head-to-head poly(vinyl bromide). Partially brominated PB has a structure of random or block sequences of butadiene units in the polymer depending on the bromination solvent but shows no stereospecificity in the CHBrCHBr-dyads. Partially brominated PB with block structure showed a microphase-separated morphology over a wide range of composition. Microphase separation is less pronounced for the more random structure of butadiene units. I.r and 13C n.m.r. spectroscopy of the partially brominated PB was used to follow the progress of the bromination. 相似文献
7.
In recent years the requirement for the reduction of energy consumption has been increasing to solve the problems of global warming and the shortage of petroleum resources. For example, in the power generation field, as thermal power generation occupied 60% of the power generation demand, considerable improvement of the thermal efficiency is required. This paper describes the pressure drop characteristics of finned tube banks used for heat exchangers in thermal power generation that were clarified by testing serrated finned tube banks with different fin heights for improved heat transfer and conventional spiral finned tube banks with different fin heights, and an equation to predict pressure drop which is necessary for the heat exchanger design is proposed. © 2006 Wiley Periodicals, Inc. Heat Trans Asian Res, 35(3): 179–193, 2006; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/htj.20112 相似文献
8.
Enhancing heat transfer ability of drag reducing surfactant solutions with static mixers and honeycombs 总被引:4,自引:0,他引:4
Yunying Qi Yasuo Kawaguchi Richard N. Christensen Jacques L. Zakin 《International Journal of Heat and Mass Transfer》2003,46(26):5161-5173
Solutions containing drag reducing additives also show reduced heat transfer which limits their use in district heating and cooling recirculation systems where heat exchange is critical. In this study, static mixers A and B and honeycombs were installed at the entrance to a heat exchanger to break the solution microstructure temporarily and thereby enhancing their heat transfer ability when passing through the heat exchanger. The effectiveness of the destructive devices in enhancing the heat transfer ability of drag reducing cationic and mixed zwitterionic/anionic surfactant solutions was investigated together with the microstructure recovery time and pressure drop penalty paid for the heat transfer enhancement. 相似文献
9.
The behavior of a premixed flame propagating from a chamber into a narrow channel at a high speed was examined using high speed and instantaneous schlieren photography, ion current measurement with electrostatic probes, and temperature measurement with an optical method. From detailed measurements of flames passing through the channel, flame extinguishment in the channel, no matter whether transient or not, was found to occur due to quenching of the reacting gas by rapid turbulent mixing with cold fresh mixture at the downstream of the contraction region and by heat transfer to the cold channel walls. Extinguishment must occur when these heat losses exceed the heat released by the chemical reaction of the flowing mixture. 相似文献
10.
S Kawaguchi S Ishimaru N Koizumi T Shimazaki Y Obitsu M Ishikawa 《Canadian Metallurgical Quarterly》1998,46(10):1047-1051
OBJECTIVE: To determine the pharmacokinetics and absolute bioavailability of ciprofloxacin in 12 critically ill patients receiving continuous enteral feeding. Design: a prospective, cross-over study. SETTING: 12-bed surgical intensive care unit in a University Hospital. PATIENTS: 12 stable critically ill patients on mechanical ventilation and receiving continuous enteral feeding (Normoreal fibres) without diarrhea or excessive residual gastric contents ( < 200 ml/4 h). None had gastro-intestinal disease, renal insufficiency (estimated creatinine clearance > or = 50 ml/min) or was receiving medications that could interfere with ciprofloxacin absorption or metabolism. MEASUREMENTS AND MAIN RESULTS: The study was carried out after the fourth (steady state) b. i. d. intravenous (i. v.) 1-h infusion of 400 mg and the second b. i. d. nasogastric (NG) dose of 750 mg (crushed tablet in suspension). Plasma concentrations were measured by high-performance liquid chromatography. The median (range) peak concentration after i. v. infusion was 4.1 (1.5-7.4) mg/l, and that after NG administration was 2.3 (0.7-5.8) mg/l, occurring 1.25 (0.75-3.33) h after dosing. The median [range] areas under plasma concentration-time curves were similar for the two administration routes (10.3 [3.3-34.6] and 8.4 [3.6-53.4] for i.v. infusion and NG administration, respectively). Ciprofloxacin bioavailability ranges from 31 to 82 % (median, 44%). CONCLUSIONS: In tube-fed critically ill patients, a switch to the NG ciprofloxacin after initial i. v. therapy to simplify the treatment of severe infections is restricted to those for whom serial assessments of ciprofloxacin levels are routinely available. 相似文献