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181.
Noboru Yamazaki Seiichi Nakahama Akira Hirao Juheiji Kawabata Hiromichi Noguchi Yasuzo Uchida 《Polymer Bulletin》1980,2(4):269-274
Summary Catalysis of cationic polyelectrolytes for the decarboxylation of 6-nitrobenzisoxazole-3-carboxylate anion was studied in a buffer solution (pH=9.0). Cross-linked poly (4-vinylpyridinium) salts prepared from 4-vinylpyridine and , -dibromides were used as cationic catalysts. The cross-linked catalysts were found to accelerate markedly the decarboxylation in comparison with the linear water-soluble analogues. Effect of the polymer structure such as the length of (CH2)x linkages between positive charges on the catalytic activity was examined. It was suggested that the acceleration by the cross-linked polymer catalysts would be due to the hydrophobic microenvironment around the catalytic sites. 相似文献
182.
Megumi Yamazaki Akihiko Nagao Kogaku Komamiya 《Journal of the American Oil Chemists' Society》1980,57(2):59-60
When using high pressure differential thermal analysis to study the stability of a fatty methyl ester or triglyceride in an
atmosphere of air, a departure from the base line in the exothermic curve is observed. The point where an extension line from
the base line intersects a tangent line to the departure curve was selected as the transition point in the exothermic curve.
For each sample studied, temperature at this transition point showed good reproducibility. The influence of sample container
and air pressure upon the temperature of the transition point in the exothermic curve (TTE) was examined. A linear correlation
between the number of double bonds in the sample and TTE was observed. 相似文献
183.
Dijin Gong Mitsuo Gen Weixuan Xu Genji Yamazaki 《Computers & Industrial Engineering》1995,29(1-4):525-530
In this paper we propose a hybrid evolutionary method for Obstacle Location-allocation problem. This problem can be described as a tri-level mixed integer programming problem. Since this problem is very complex and with many local solutions, no direct method is effective to solve it. Heuristic methods were proposed to it, but optimality is not guaranteed yet. Our hybrid evolutionary method adopts the main structure of Genetic Algorithms (GA) absorbing ideas from Evolutionary Strategy (ES) and combines with some traditional optimization techniques. In this way we can pursue global optimization maintaining a good efficiency of our method. A case study shows the effectiveness of this method. 相似文献
184.
Gwen Jones Joanna R. Groza Kazuo Yamazaki Kazuo Shoda 《Materials and Manufacturing Processes》1994,9(6):1105-1114
Plasma Activated Sintering (PAS) is a short time, high temperature densification process based on three main contributions: resistance sintering, pressure application, and plasma generation. PAS was applied to the densification of untreated tungsten powder at temperatures between 2050 and 2685 K for 2 to 8 minutes in air or vacuum. The density values ranged between 80.2 and 91.5 % of theoretical density. The initial micron grain size was retained after consolidation at temperatures of 2350 and 2400 K. Net shape consolidation of a cutting tool was achieved by PAS densification of WC-Co powders.
The clean grain boundary observed by high resolution electron microscopy in some of the PAS consolidated specimens suggests that activation of the powder surfaces may take place to enhance the densification process. This physical surface activation may be responsible for enhanced sintering of tungsten particles with no need for additives. The major benefits from this new non-conventional technique include an unusual short densification time (minutes as compared to hours for conventional densification), retention of unique initial microstructures and properties, as well as sintering in one single step with no requirements for binders, prior cold compaction or controlled atmospheres. 相似文献
The clean grain boundary observed by high resolution electron microscopy in some of the PAS consolidated specimens suggests that activation of the powder surfaces may take place to enhance the densification process. This physical surface activation may be responsible for enhanced sintering of tungsten particles with no need for additives. The major benefits from this new non-conventional technique include an unusual short densification time (minutes as compared to hours for conventional densification), retention of unique initial microstructures and properties, as well as sintering in one single step with no requirements for binders, prior cold compaction or controlled atmospheres. 相似文献
185.
Xi Zhang Xiaodong Tian Kazuo Yamazaki 《The International Journal of Advanced Manufacturing Technology》2010,48(1-4):251-265
In computer numerical control machine tools, using machining simulation to prevent collision becomes more and more popular due to its efficiency and low cost. However, if the entire digital model of the machining setup does not exist, the simulation is not applicable. As a result, the operator has to manually check the numerical control program, which is a time-consuming and error-prone process. In this paper, an on-machine vision system is presented to quickly construct the digital model based on the actual machining setup. The total construction for a complex setup can be done within a few minutes. Several key technologies have been developed. First, a 2D edge feature detection algorithm has been designed which will extract the edges of the object of interest by processing both the real and virtual images. Second, a stereo vision system is developed which will obtain the three-dimensional (3D) edge data of the object of interest. A new algorithm is presented to solve correspondence, which is the key problem of the stereovision system. Furthermore, the 3D object recognition algorithm is developed to let the system intelligently search for the matched solid model in the database and import it into the virtual environment with an accurate pose. Finally, experiments are carried out to test the developed system. 相似文献
186.
Hiroyoshi Yamazaki Kohji Koshiji 《IEEJ Transactions on Electrical and Electronic Engineering》2009,4(1):107-113
A spatial filtering is a useful method for suppressing unwanted reflection from undesired scatters on radar cross-section (RCS) measurements. Highly accurate RCS measurements for stealth-designed targets are generally performed by using full-scale models. However, it is difficult to carry out a measurement of a large full-scale target, because a vast RCS measurement site which satisfies the far-field criterion without undesired scatters is required. In this paper, we have applied the filtering method to RCS measurements in a near field and investigated the validity of that method by varying the scanning angular span. First, a distribution of scattering sources including undesired scatters is predicted from near-field spherical- or cylindrical-scanning data. Next, undesired scatters are suppressed using the spatial filtering. Finally, RCS values of the test target are calculated by taking the Fourier transform of the filtered scattering source distribution. Using electromagnetic simulations, we have validated the RCS measurement method by comparing predicted RCS with reference data as far-field RCS of the test target. As a result, predicted RCS profiles closely matched with reference data. In conclusion, the proposed method is useful for RCS measurements within the unsuitable near zone. Copyright © 2009 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. 相似文献
187.
Yamazaki T Kashiwagi A Kuramochi K Ohtsuka M Hashimoto I Watanabe K 《Journal of electron microscopy》2008,57(6):181-187
The quantitative measurement of a crystal bending effect is performed using low-order zone-axis convergent beam electron diffraction (CBED) patterns. Although the accuracy of the present method is inferior to that of the method of using split higher order Laue zone lines, this method enables us to estimate the crystal bending effect at a region very close to the interface and to easily judge whether the crystal bending effect results in a tensile bend or a compressive bend. As an application of the present method, the crystal bending effect at a region close to the SiGe/Si interface was measured. It was found that the crystal bending effect is due to a thin-foil relaxation of almost 0.3 degrees at a region that is approximately 10 nm away from the interface. 相似文献
188.
Yamada E. Sano A. Masuda H. Yamazaki E. Kobayashi T. Yoshida E. Yonenaga K. Miyamoto Y. Ishihara K. Takatori Y. Yamada T. Yamazaki H. 《Electronics letters》2008,44(24):1417-1418
Spectrally efficient (2bit/s/Hz) 1 Tbit/s DWDM transmission of 111 Gbit/s no-guard-interval PDM CO-OFDM signals with 50 GHz spacing over DSF is demonstrated. The record transmission distance of 2100 km was achieved for a 100 Gbit/s-data-rate CO-OFDM system. 相似文献
189.
Shigeru Katayama Rio Yamazaki Hikaru Umise Hsu Pei Han Toshihiro Mihara Kimiko Uchiyama Hajime Takahashi Soichiro Nakamura 《Molecular nutrition & food research》2023,67(16):2200212
Scope
Ultraviolet B (UVB) radiation causes skin barrier dysfunction, leading to decreased water-holding capacity, impaired epidermal barrier function, and increased skin thickness. This study investigates the protective effects of oral administration of Lacticaseibacillus paracasei K71 against skin barrier dysfunction in UVB-irradiated mice.Methods and results
Mice are fed diets with or without K71 and irradiated with UVB three times a week for 12 weeks. Oral administration of K71 suppresses UVB-induced decrease in stratum corneum water content, mitigates the increase of transepidermal water loss, and decreases epidermal thickness of the dorsal skin. Treatment with K71 reverses the upregulation of inflammatory cytokines and the activation of nuclear factor-κB induced by UVB irradiation and upregulates the expression of anti-inflammatory IL-10 in the dorsal skin. Notable upregulation of IL-10 is observed in the spleens of K71-treated mice. K71 treatment enhances IL-10 production in J774.1 macrophages; however, this enhancement is diminished by inhibiting K71 phagocytosis and TLR3. Furthermore, transfection using K71 RNAs significantly increases IL-10 production.Conclusion
These results indicate that K71 may alleviate UVB-induced skin barrier dysfunction by attenuating inflammation via increasing IL-10 production and that K71 RNAs may induce IL-10 production in macrophages. Therefore, K71 may be beneficial for preventing skin barrier dysfunction. 相似文献190.
Yosuke Yamazaki Takayuki Otsuka Kazuo Okamura Yoji Shibutani 《Materials Science & Technology》2020,36(6):750-758
ABSTRACTHeat treatment, such as quenching and carburising, often involves volume change caused by phenomena such as thermal expansion, phase transformation, and carbide precipitation during tempering. During the tempering process, an external force induces additional plastic deformation. The authors termed this phenomenon ‘tempering plasticity’. In this study, we performed crystal plasticity analysis using fast Fourier transform considering the volume change in carbides to assess the mechanism of tempering plasticity. As a result, tempering plastic strain occurred as the volume fraction of carbide increased, and the tempering plastic phenomenon could be reproduced based on the transformation model proposed by Greenwood–Johnson. The result supports the idea that the volume change accompanied by carbide precipitation is an important mechanism that invokes tempering plasticity. 相似文献