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101.
Jung Bok Jo Yasuhiro Tsujimura Mitsuo Gen Genji Yamazaki Jae Uk Lee 《Computers & Industrial Engineering》1997,33(3-4):557-560
The purpose of this paper is to combine the ability of fuzzy set to represent more realistic situations with the well-established traditional queueing system model problem. We are forced to employ subjective probabilities when there is no information about a model or some parameters of a model are vague. The information and data are very fuzzy, because they are frequently very little, 'and may be sometimes obtained from experts subjectively. We apply fuzzy set theory to the closed multiclass model with the fuzzy queues. thus, we represent the characteristic and performance of the closed multiclass model based on the proposed fuzzy set theory. 相似文献
102.
M Tsujimura N Dohmae M Odaka M Chijimatsu K Takio M Yohda M Hoshino S Nagashima I Endo 《Canadian Metallurgical Quarterly》1997,272(47):29454-29459
Nitrile hydratase (NHase) from Rhodococcus sp. N-771 is a photoreactive enzyme that is inactivated by nitrosylation of the non-heme iron center and activated by photodissociation of nitric oxide (NO). To obtain structural information on the iron center, we isolated peptide complexes containing the iron center by proteolysis. When the tryptic digest of the alpha subunit isolated from the inactive form was analyzed by reversed-phase high performance liquid chromatography, the absorbance characteristic of the nitrosylated iron center was observed in the peptide fragment, Asn105-Val-Ile-Val-Cys-Ser-Leu-Cys-Ser-Cys-Thr-Ala-Trp-Pro-Ile-Leu - Gly-Leu-Pro-Pro-Thr-Trp-Tyr-Lys128. The peptide contained 0.79 mol of iron/mol of molecule as well as endogenous NO. Subsequently, by digesting the peptide with thermolysin, carboxypeptidase Y, and leucine aminopeptidase M, we found that the minimum peptide segment required for the nitrosylated iron center is the 11 amino acid residues from alphaIle107 to alphaTrp117. Furthermore, by using mass spectrometry, protein sequence, and amino acid composition analyses, we have shown that the 112th Cys residue of the alpha subunit is post-translationally oxidized to a cysteine-sulfinic acid (Cys-SO2H) in the NHase. These results indicate that the NHase from Rhodococcus sp. N-771 has a novel non-heme iron enzyme containing a cysteine-sulfinic acid in the iron center. Possible ligand residues of the iron center are discussed. 相似文献
103.
BaZrSi3O9:Eu2+, Sm3+ (Em:525 nm) is prepared. The role played by the trivalent co-doping ion Sm3+ in the afterglow and the type of trap are clarified. BaZrSi3O9:Eu2+, Sm3+ is found to produce Sm2+ during the excitation by X-ray absorption near-edge structure (XANES), etc., and it is thus proved that Sm3+ exists as an electron trap in the afterglow process. In the field of persistent phosphors activated by Eu2+ and Re3+ such as Sm3+ or Dy3+ having been widely utilized as emergency guide lights, clock faces, etc. for > 25 years, for the first time it is successfully observed that after excitation Re2+ is formed, transferring its electron to 5d band of Eu2+, returning to Re3+ by itself, where the decrease in Sm2+ coincides with the increase in Sm3+, and the two decay time τ1 and τ2 of PL (5D0→7F0) of Sm2+ coincides with the two evolution time of PL (5d→4f) of Eu2+. The behavior of electron transfer from Sm2+ to Eu2+ as a key of afterglow is detected. The detailed afterglow mechanism is proposed by analysis of thermoluminescence and defect reaction, which is very important for the in-depth investigation of the long afterglow material and the further improvement of the mechanism. 相似文献
104.
Masatoshi Ohara Shin-ichiro Tanifuji Yuya Sasai Takemasa Sugiyama Sho Umemoto Jun-ichi Murata Isao Tsujimura Shin-ichi Kihara Kentaro Taki 《American Institute of Chemical Engineers》2020,66(11):e17018
A self-wiping co-rotating twin-screw extruder (TSE) is operated in a starved state in which the screws are partially filled with resin. Understanding the resin distribution on the screw surface of a TSE in this state is essential for the design, operation, and maintenance of the twin-screw extrusion process. Accordingly, in this study, the circumferential and axial distribution of resin in a TSE were simulated using a novel method combining the mathematical formulation of Hele–Shaw flow, the finite element method, and a newly developed down-wind pressure updating scheme. The results of the simulation were found to be in good agreement with experimental measurements. The proposed simulation method enables the detailed visualization of resin distribution in the entire axial and circumferential directions over the length of a TSE, improving the ability to determine both the devolatilization and fiber attrition during the extrusion process. 相似文献
105.
Ohkuri Takatoshi; Yamagishi Akihiko 《Protein engineering, design & selection : PEDS》2003,16(8):615-621
We have investigated factors affecting stability at the subunitsubunitinterface of the dimeric enzyme 3-isopropylmalate dehydrogenase(IPMDH) from Bacillus subtilis. Site-directed mutagenesis wasused to replace methionine 256, a key residue in the subunitinteraction, with other amino acids. Thermal stability againstirreversible inactivation of the mutated enzymes was examinedby analyzing the residual activity after heat treatment. Themutations M256V and M256A increased thermostability by 2.0 and6.0°C, respectively, whereas the mutations M256L and M256Ihad no effect. Thermostability of the M256F mutated enzyme was4.0°C lower than that of the wild-type enzyme. To our surprise,increasing the hydrophobicity of residue 256 within the hydrophobiccore of the enzyme resulted in a lower thermal stability. Themutated enzymes showed an inverse correlation between thermostabilityand the volume of the side chain at position 256. Based on theX-ray crystallographic structure of Escherichia coli IPMDH,the environment around M256 in the B.subtilis homolog is predictedto be sterically crowded. These results suggest that Met256prevents favorable packing. Introduction of a smaller aminoacid at position 256 improves the packing and stabilizes thedimeric structure of IPMDH. The van der Waals volume of theamino acid residue at the hydrophobic subunit interface is animportant factor for maintaining the stability of the subunitsubunitinterface and is not always optimized in the mesophilic IPMDHenzyme. Received September 3, 2002; revised June 13, 2003; accepted June 20, 2003. 相似文献
106.
Novel Synthesis of Silica-Coated Ferrite Nanoparticles Prepared Using Water-in-Oil Microemulsion 总被引:2,自引:0,他引:2
Teruoki Tago Takatoshi Hatsuta Kanta Miyajima Masahiro Kishida Shizuka Tashiro Katsuhiko Wakabayashi 《Journal of the American Ceramic Society》2002,85(9):2188-2194
Ferrite nanoparticles (magnetite (Fe3 O4 ) and cobalt-ferrite (Co x Fe3− x O4 )) coated with silica (SiO2 ) were prepared using water-in-oil microemulsion of a polyoxyethylen(15)cetylether/cyclohexene system. Observation via transmission electron microscopy revealed that the ferrite nanoparticles were located nearly at the center of spherical SiO2 particles. The sizes of Fe3 O4 and Co x Fe3− x O4 nanoparticles were in the range of 8–12 nm and 10–14 nm, respectively, and the thickness of the SiO2 layer was ∼14.0 nm. The solid solution of cobalt ions into Fe3 O4 to form Co x Fe3− x O4 nanoparticles led to an increase in the coercivity of the SiO2 -coated ferrite nanoparticles. The coercivity increased with increasing amounts of added cobalt, obtaining a maximum value of 780 Oe around a Co/Fe ratio of 0.3–0.4. 相似文献
107.
Magnetic properties of metal layer deposited by reduction of polymer containing metal ions were investigated. Varying the ratio of the cobalt ion to the nickel ion in the polymer, the coercivity, the maximum flux density and the remanent flux density of the deposited metal layer were changed from 100 to 600 Oe, from 1 000 to 12 600 G and from 500 to 7 600 G, respectively. The X-ray diffraction pattern of the metal layer with excellent magnetic properties gives distinct peaks corresponding to the (101) and (100) planes of the crystal of α-Co. This suggests that such a deposited metal layer has the structure of highly crystalline metal layer. 相似文献
108.
Shinji Kodama Kazuki Sugiura Shota Nakanishi Yoshihiro Tsujimura Manabu Tanaka Anthony B. Murphy 《Welding International》2013,27(4):262-269
In order to clarify the nitrogen absorption mechanism in gas tungsten arc welding, the measurement of the weld metal nitrogen content under nitrogen mixture shielding gases, and the numerical analysis of plasma heat source characteristics in nitrogen dissociation phenomenon were conducted. The nitrogen content of weld metal produced by He arc reduces to approximately a half relative to that by Ar arc in the shielding gas condition of less than about 1% mixture ratio. Additionally, it is assumed that a decline in the plasma temperature in the vicinity of the molten pools due to the generation of metal vapour, accompanied by a reduction in atom-like nitrogen content, cause intense impact on the reduction mechanism of weld metal nitrogen content in a He arc. 相似文献
109.
Nanako Kato Tomoaki Masuzawa Yuki Kudo Yuka Kuwajima Hisato Yamaguchi Ken Okano Takatoshi Yamada Ichitaro Saito Tim Butler Nalin L. Rupesinghe Gehan A.J. Amaratunga 《Diamond and Related Materials》2008,17(2):95-99
An imaging device that could detect weak light of approximately 0.001 lx with high SN ratio is capable of opening up the possibility of creating artificial visions as a substitute for a human eye. In terms of sensitivity and SN ratio, amorphous selenium (a-Se) is known to be one of the best candidates among other photoconductive target. Combined with a-Se, a diamond cold cathode would be one of the best options in order to steadily emit electrons under low vacuum. The a-Se film is modified with Arsenic (As) and Tellurium (Te) to prevent crystallization and narrow the optical gap for red light detection. An RGB filtered light from a halogen light source was illuminated onto this modified a-Se film and the photo-response was measured for each color. The device could detect extremely weak illumination of under 0.39 lx, which is approximately the darkness under moonlight. Results of the photo-response compared between films with and without Te clarified that Te dopants enhances red light detection significantly. The illuminated light was then pulsed at 10 mHz and the current to time stability was observed. It showed clear correspondence between the intensity of the luminance and current, which the Te modified samples showed good response to other colored light as well. 相似文献
110.
Repassivation behavior of type-312L stainless steel containing 6% of molybdenum was examined in NaCl solution using in situ micro-indentation technique, together with type-304 and 316L stainless steels. High stability of the passive film formed on the type-312L stainless steel was also examined by depth profiling analysis of passive films using glow discharge optical emission spectroscopy (GDOES). In 0.9 mol dm−3 NaCl solution at 296 K the type-304 and 316L stainless steels are passive only up to 0.3 V (SHE), above which pitting corrosion occurs. In contrast, no pitting corrosion occurs on type-312L stainless steel. Despite the significant difference of the pitting corrosion resistance, the repassivation kinetics of the three stainless steels, examined by micro-indentation at 0.3 V (SHE), is similar. The presence of molybdenum in the stainless steel does not influence the repassivation kinetics. The charge required to repassivate the ruptured type-312L stainless steel surface increases approximately linearly with the potential, even though the passivity-maintaining current increased markedly at potentials close to the transpassive region. Repassivation occurs without accompanying significant dissolution of steel, regardless of the stability of passive state. Depth profiling analyses of the passive films on the type-312L stainless steels formed at several potentials revealed that molybdenum species enrich in the outer layer of the passive film, below which chromium-enriched layer is present. The permeation of chloride ions may be impeded by the outer layer containing molybdate, enhancing the resistance against the localized corrosion of the type-312L stainless steel. 相似文献