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排序方式: 共有518条查询结果,搜索用时 15 毫秒
121.
Hiroshi Hirano Joji Kadota Yasuyuki Agari Toshihiko Harada Mitsuaki Tanaka Kiichi Hasegawa 《Polymer Engineering and Science》2007,47(3):262-269
A series of sulfur‐containing linear polythioesters were synthesized from 4,4′‐biphenyldithiol (BPT) and bifunctionally aliphatic acyl dichlorides (ACs) by means of polycondensation. Polycondensations of BPT with azelaoyl chloride or sebacoyl chloride chosen as a model reaction system were investigated in several solvents by solution polycondensation, to find an optimal solvent to achieve high molecular weight and quantitative yield. Thus, all the polythioesters from BPT and AC (methylene number of 3–10) were synthesized in chloroform and their structures were confirmed by 1H‐NMR and Fourier transform infrared spectrophotometer. They were also evaluated by thermogravimetry and differential scanning calorimeter (DSC). Almost all of the BPT, polythioesters exhibited two distinct exothermic and endothermic peaks on first cooling and second heating in their DSC curves, respectively. Polarized microscope (PLM) observation clarified that the higher transition temperatures were isotropic temperatures (Tis). The odd–even effect between Ti and the methylene number was observed in these BPT polythioesters. Furthermore, almost all of the polythioesters showed thermotropic liquid‐crystalline behavior, as evidenced by a PLM observation. To know the effect of introduction of sulfur on adhesive properties of the polythioester/copper junction, a single lap shear test was carried out in comparison with corresponding 4,4′‐biphenyldiol (BPH) polyesters derived from BPH and ACs. It was clarified that the BPT polythioesters have greatly higher adhesive strengths in comparison with the BPH polyesters. POLYM. ENG. SCI., 47:262–269, 2007. © 2007 Society of Plastics Engineers. 相似文献
122.
Takuji Murata Hiroshi Tamai Takao Morinobu Mitsuhiro Manago Akira Takenaka Hiroyuki Takenaka Makoto Mino 《Lipids》1992,27(11):840-843
The β-carotene concentrations in plasma, blood cells and buccal mucosal cells were determined by high-performance liquid chromatography
with electrochemical detection. This method was 1,000 times more sensitive than the conventional spectrophotometric method.
Polymorphonuclear cells and red blood cells had lower β-carotene levels than the other cells. After oral administration of
580 mg/day of all-trans β-carotene to human male volunteers for a week, the β-carotene concentrations in all cell types increased at least several
times above the original levels. 相似文献
123.
Yosuke Iwata Mitsuhiro Murata Kohei Tanaka Tadashi Ohtake Hidefumi Yoshida Koichi Miyachi 《Journal of the Society for Information Display》2014,22(1):35-42
We have developed a novel super fast response (SFR) thin‐film transistor liquid crystal display (TFT‐LCD) with an extremely wide temperature range. Nematic liquid crystal molecules with positive dielectric anisotropy are vertically aligned initially. Any gray‐to‐gray response is forcibly controlled by applying an electric field. Response times of the SFR TFT‐LCD are over several times shorter than those of conventional LCDs such as vertical alignment or in‐plane switching LCDs. 相似文献
124.
Velocities of reactive and non‐reactive flows, where NO2 molecules were seeded, were measured by a NO‐based Laser Induced Fluorescence (LIF) method. NO2 dilute gases were injected from a round tube with an inner diameter of 2 cm and its flow rate was 10 liters/minute or 20 liters/minute. Experiments were performed for 4 conditions—non‐reactive flows of NO2 dilute gases at two flow rates, an unburnt gas flow of the premixed flame with NO2 addition, and an unburnt gas flow of the diffusion flame with NO2 addition. NO molecules were produced in flows by planar emissions of 355 nm laser rays from an Nd:YAG laser system, and NO‐LIF images were taken in a pre‐determined delay. An ICCD camera, a dye laser excited by an excimer laser, and Nd:YAG laser were strictly synchronized by a pulse generator. NO‐LIF signals, which were emitted by photochemically produced NO from NO2, were strong enough to measure the NO displacements in the case of non‐reactive flows, while with only a few ppm concentrations of NO2 added it was possible to measure the velocity in detail. Although fluctuations of NO trajectories were observed at the flow rate of 20 liters/minute, instantaneous velocities were measured accurately. In the case of the unburnt gas of the diffusion flame, NO‐LIF signals were also strong, and profiles of NO produced by NO2 photodissociation were clearly measured. Profiles of NO produced by NO2 photodissociation in the unburnt gas of the premixed flame were also clearly measured, even in the vicinity of the reaction zone. It can be seen that velocities were measured correctly in the unburnt regions of the premixed and the diffusion flames. With this method, it was possible to measure velocities of both steady and unsteady flows. © 2004 Wiley Periodicals, Inc. Heat Trans Asian Res, 34(1): 40–52, 2005; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/htj.20038 相似文献
125.
126.
Mitsuhiro Okayasu Satoshi Takasu Shigeki Yoshie 《Journal of Materials Processing Technology》2010,210(11):1529-1535
The specific objective in this work is an exploration of the material properties produced by a recently developed continuous casting technique. The study focuses on an Al–Cu alloy provided by the Ohno continuous casting process. The experimental approaches give rise to unusual microstructural characteristic in the cast samples, namely a fine lamellar eutectic structure with unidirectional growth along its axial direction together with a regularly oriented lattice structure. Such microstructural characteristics significantly increase the tensile and fatigue properties. 相似文献
127.
Kazunori Kadota Hikaru Tamura Yoshiyuki Shirakawa Yuichi Tozuka Atsuko Shimosaka Jusuke Hidaka 《Chemical Engineering Research and Design》2014
The aim of the present work is to apply the liquid–liquid interfacial crystallization using a piezoelectric inkjet nozzle to the sol–gel processing. The instillation process was compared with the batch process to elucidate the effectiveness of the inkjet technique on the liquid–liquid interfacial sol–gel processing. The effect of frequency and water concentration in titanium tetraisopoxide (TTIP) solution on titania particle properties was investigated for sol–gel processing with a piezoelectric inkjet nozzle. Titania particles produced by each process were calcined at 500 °C. The crystal structure, morphology, pore size distribution and specific surface area of titania particles were evaluated by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), nitrogen physisorption measurement. The photocatalytic activity of titania particles was evaluated by the photodegradation of methylene blue solution under UVC light irradiation. 相似文献
128.
Mitsuhiro Okayasu Kazuto Sato Yoko Kusaba 《Journal of the European Ceramic Society》2011,31(1-2):129-140
To better understand the domain switching characteristics of lead zirconate titanate (PZT) ceramics, the orientations of domains have been directly investigated during loading and unloading using various experimental techniques. Upon loading, linear and non-linear fracture mechanics of the PZT ceramics are observed. The slope of the stress–strain response is attributed mainly to lattice strain and domain switching strain. During the loading process, electrical activity also occurs several times in the PZT ceramics. This activity is related to a lightning-like phenomenon and consists of a bright flash with a click. This electrogenerative event is caused by severe domain switching. The characteristics of domain switching and reverse switching are detected during the loading and unloading processes. The amount of domain switching depends on the grain, due to different stress levels. In addition, two patterns of 90° domain switching systems are characterized, namely (i) 90° turn about the tetragonal c-axis and (ii) 90° rotation of the tetragonal a-axis. 相似文献
129.
Mitsuhiro Kataoka Chiyu Zhu Franz A.M. Koeck Robert J. Nemanich 《Diamond and Related Materials》2010,19(2-3):110-113
Nitrogen-doped homoepitaxial diamond films were synthesized for application as low-temperature thermionic electron emitters. Thermionic electron emission measurements were conducted where the emission current was recorded as a function of emitter temperature. At a temperature < 600 °C an emission current was detected which increased with temperature, and the emission current density was about 1.2 mA/cm2 at 740 °C. The electron emission was imaged with photoelectron emission microscopy (PEEM) and thermionic field-emission electron microscopy (T-FEEM). The image displayed uniform electron emission over the whole surface area. Thermionic emission and ultraviolet photoemission spectroscopy were employed to determine the temperature dependent electron emission energy distribution from the nitrogen-doped homoepitaxial diamond films. The photoemission spectra indicated an effective work function of 2.4 eV at 550 °C. These values indicate reduced band bending and establish the potential for efficient electron emission devices based on nitrogen-doped homoepitaxial diamond. 相似文献
130.