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91.
Yoshiyuki Tomita 《Journal of Materials Science》1989,24(4):1357-1362
The modified heat treatment, which produces a mixed structure of martensite and lower bainite through short-term isothermal
transformation at just above the martensitic transformation temperature,M
s
temperature, followed by oil quenching (after conventional austenitization), has been applied to three high-carbon low-alloy
steels with different levels of nickel and chromium contents at similar molybdenum levels, in which carbon was allowed to
replace relatively expensive additions of nickel and chromium, for their ultra-high strength application. The significant
conclusions are as follows: an ultra-high strength steel of 1900 M Pa yieldstress grade with a high toughness level can be
obtained when about 60 vol % lower bainite is associated with 473 K tempered martensite of 0.60% C-1.80% Ni-0.80% Cr-0.25%
Mo steel. If approximately 25 vol % lower bainite appears in 673 K tempered martensite of the steel, a 1700 M Pa yield-stress
grade steel with high toughness and moderate ductility levels can be attained. However, alloying nickel is essential to some
extent for development of the mechanical properties with the modified heat treatment suggested in the present work. 相似文献
92.
Hayato Takasago Eishi Gofuku Mitsuyuki Takada Yoshiyuki Morihiro 《Journal of Electronic Materials》1989,18(5):651-655
When electric resistivity of Thick Film Resistor (TFR) is adjusted to the desired value, laser beam is irradiated onto the
resistor material so that a part of the resistor material is instantaneously vaporized and cut away. This conventional laser
trimming method to adjust the resistivity of TFRs is an indispensable technique for manufacturing elec-tronic devices such
as hybrid ICs. A peculiar phenomena was revealed by us, that is, when specially selected pulse laser beams were irradiated
to TFR, the TFR was surface modified without cutting grooves, and then resistivity of the TFR was decreased. We completed
the advanced laser process to apply this peculiar phenomena. 8 By comparing with conventional trimming processes, we can show
prominent features of the advanced process, for example, resistivity of fine size TFR (300 micrometers-width and under) can
be easily controlled. The decrease in resistivity of the TFR is considered to result from the decrease in specific resistivity
of glass in the TFR. Because it is considered that the glass in the TFR is heavily doped with ruthenium impurities during
the surface modification due to results of morphology observations and x-ray diffraction analysis. We have applied this advanced
laser process to fine size TFR (300 micrometers-width), and developed high density hybrid ICs. 相似文献
93.
Jun Kawaji Shuichi Suzuki Yoshiyuki Takamori Makoto Morishima 《Electrochimica acta》2010,55(27):8018-8022
To improve methanol-oxidation performances of membrane-electrode assemblies composed of a hydrocarbon-based ionomers, the resistances involved in the reaction were decreased. Electrochemical impedance spectroscopy revealed that the proton-conductive resistance (Ri) in the anode was decreased from 0.54 to 0.40 Ω cm2 by increasing a loading ratio of platinum-ruthenium to carbon support of anode catalyst from 54 to 73 wt.%. In addition, Ri was decreased to be 0.25 Ω cm2 by increasing ion-exchange capacity (IEC) of the ionomer from 1.4 to 2.9 mequiv. g−1. Consequently, the polarization resistance of the anode was significantly decreased, in turn, increasing current density of methanol oxidation at the potential of 0.45 V from 0.110 to 0.244 A cm−2. 相似文献
94.
Summary Deuterium NMR measurements have been performed for dimer liquid crystals (DLC) having structures such as NC-O(CH2)nO-CN (CBA) with n=9, 10. Fully deuterated CBAs with n=9 and 10 exhibit, respectively, three and four splittings in the D-NMR spectra. By using partially deuterated samples, the signals corresponding to the largest splittings were found to include contributions from the - and -CD2 groups. The origins of the rest of the signals were elucidated by the RIS method previously established. Characteristic properties of the nematic mesophase were estimated for CBA-10. The results were found to be consistent with those of the previous analysis on Griffin et al.'s DLC. 相似文献
95.
Two series of polypropylenes with different molecular weight distribution and tacticity characteristics were injection molded into flexural test specimens by varying cylinder temperature and the effects of the molecular weight distribution and tacticity on the structure and properties of the moldings were studied. Measured propertied were flexural modulus, flexural strength, heat distortion temperature, Izod impact strength, and mold shrinkage and structures studied were crystallinity, the thickness of skin layer, a*‐axis‐oriented component fraction and crystalline orientation functions. The relations between the structures and properties were also studied. It was found that the molecular weight distribution and tacticity characteristics affect the properties mainly through the molecular orientation and crystallinity, respectively. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 2142–2156, 2002 相似文献
96.
In this work, entropic expressions of UNIFAC‐FV and Entropic‐FV models were evaluated by using an extensive database of infinite dilution vapor–liquid equilibrium (VLE) data of athermal systems containing polypropylene, polyethylene, and polyisobutylene. For the infinite dilution athermal systems, performance of the Entropic‐FV model was better than that of the UNIFAC‐FV model. Then, finite concentration VLE data of non‐athermal systems that consisted of 16 polymers and 36 solvents containing a large variety of solvent–polymer systems ranging from nonpolar to polar substances were considered to optimized 46 pairs of group interaction parameters of the Entropic‐FV model. For systems containing polar solvents of three types of solvents studied, revised group interaction parameters gave significant improvements from 17.9 to 13.0% average absolute deviation (AAD) of solvent activities. For overall results, improvements were achieved from 15.1 to 12.4% AAD. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 1145–1153, 2005 相似文献
97.
Liping Yao Zhong Zeng Hiroshi Mizuseki Yoshiyuki Kawazoe 《International Journal of Thermal Sciences》2010,49(12):2413-2418
Convection control of three-dimensional thermocapillary flow by a rotating magnetic field (RMF) was simulated numerically, and the RMF infinite and RMF Φ1–Φ2 models were compared. The results of using both RMF models demonstrate that the transverse RMF stirs convection in an azimuthal direction and suppresses convection in the axial direction, which is helpful for the three-dimensional melt convection to become axisymmetric. Compared to the RMF Φ1–Φ2 model, however, the over-simplified RMF infinite model leads to a relatively large deviation. With the same magnetic field (7 mT, 50 Hz), the RMF infinite model results in a larger azimuthal velocity and a smaller axial velocity. 相似文献
98.
Operation of a two-stage fermentation process producing hydrogen and methane from organic waste 总被引:7,自引:0,他引:7
A pilot-scale experimental plant for the production of hydrogen and methane by a two-stage fermentation process was constructed and operated using a mixture of pulverized garbage and shredded paper wastes. Thermophilic hydrogen fermentation was established at 60 degrees C in the first bioreactor by inoculating with seed microflora. Following the hydrogenogenic process, methanogenesis in the second bioreactor was conducted at 55 degrees C using an internal recirculation packed-bed reactor (IRPR). After conducting steady-state operations under a few selected conditions, the overall hydraulic retention time was optimized at 8 d (hydrogenogenesis, 1.2 d; methanogenesis, 6.8 d), producing 5.4 m3/m3/d of hydrogen and 6.1 m3/m3/d of methane with chemical oxygen demand and volatile suspended solid removal efficiencies of 79.3% and 87.8%, respectively. Maximum hydrogen production yield was calculated to be 2.4 mol/mol hexose and 56 L/kg COD loaded. The methanogenic performance of the IRPR was stable, although the organic loading rate and the composition of the effluent from the hydrogenogenic process fluctuated substantially. A clone library analysis of the microflora in the hydrogenogenic reactor indicated that hydrogen-producing Thermoanaerobacterium-related organisms in the inoculum were active in the hydrogen fermentation of garbage and paper wastes, although no aseptic operations were applied. We speculate that the operation at high temperature and the inoculation of thermophiles enabled the selective growth of the introduced microorganisms and gave hydrogen fermentation efficiencies comparable to laboratory experiments. This is the first report on fermentative production of hydrogen and methane from organic waste at an actual level. 相似文献
99.
Naota Torii Atushi Okai Kazuaki Shibuki Taku M. Aida Masaru Watanabe Masayuki Ishihara Hiroichi Tanaka Yoshiyuki Sato R.L. Smith 《Biomass & bioenergy》2010,34(6):844-850
To convert cellulosic organics contained in industrial paper sludge into glucose, reaction of pseudo paper sludge composed of cellulose and inorganic compounds (calcium carbonate (CaCO3), talc (Mg3(Si4O10)(OH)2), kaolin (Al2(Si2O5)(OH)4)) under hydrothermal conditions was studied. Significant amounts of glucose (ca. 23%) could be produced from cellulose in the absence of CaCO3 for reaction in water at 523 K and 12 min reaction time. On the other hand, in the presence of CaCO3, most glucose decomposed over all conditions, whereas the addition of talc and kaolin to the mixtures increased the glucose yield to about 30%. For the case of chemical recycle of paper sludge with hydrothermal treatment to obtain d-glucose, it can be concluded that it is preferable to separate the calcium carbonate from the paper sludge before hydrothermal treatment. 相似文献
100.