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排序方式: 共有241条查询结果,搜索用时 15 毫秒
101.
Y Adachi Y Kobayashi H Ida R Yasumizu A Okamura H Kayatani N Teranishi M Inaba A Sugihara H Genba Y Eto S Ikehara 《Canadian Metallurgical Quarterly》1998,40(4):374-377
The freeze-dried powder of Lumbricus rubellus earthworm was administered orally to rats and its fibrinolytic and antithrombotic effects were investigated. The fibrinolytic activity of plasma was determined by measuring the plasmin activity of the euglobulin fraction and was increased to two-folds of the control at a dose of 0.5 g/kg/day and five times with 1 g/kg/day after 4-day administration. The antithrombotic effect was studied in an arterio-venous shunt model of rats. The thrombus weight decreased significantly from 43.2 mg to 32.4 mg at a dose of 0.5 g/kg/day after 8-day treatment. The level of fibrinogen/fibrin degradation product (FDP) in serum was elevated in a dose-dependent manner during the treatment period. On the 8th day after administration, the FDP value was increased to 7.7 micrograms/ml compared with the control value of 3.3 micrograms/ml. These results support that earthworm powder is valuable for the prevention and/or treatment of thrombotic conditions. 相似文献
102.
103.
Hiroshi Tanaka Seiki Fukai Nozomu Uchida Keizo Uematsu Akira Sakamoto Yoshihiko Nagao 《Journal of the American Ceramic Society》1994,77(12):3077-3080
To study independently the effects of moisture on the structure and the mechanical strength of the binder in green bodies, specimens of the system alumina/PVA were formed with spray-dried granules of various moisture contents. The structure and fracture strength of these specimens then were examined after their moisture contents had been adjusted to specified values. As moisture content increased in the granules during compaction, the density and strength of the green body also increased. The accompanying change in the fracture mode, from intergranular to transgranular, showed that the strength of the green bodies was affected more significantly by bonding between granules than by bonding between powder particles. 相似文献
104.
Keizo Uematsu Masayori Miyashita Jin-Young Kim Nozomu Uchida 《Journal of the American Ceramic Society》1992,75(4):1016-1018
The morphological change of natural pores with densification was examined in an alumina green body. The liquid-immersion technique was used for observing pores inside the body before and after sintering. In this technique the specimen is made transparent by an adequate immersion liquid and observed with a transmission optical microscope. Growth of large pores with densification was observed and is discussed along with past thermodynamic consideration of pore growth. Supplemental investigation of the results was conducted by SEM and mercury porosimetry. 相似文献
105.
Satoh T. Mutoh N. Furumiya M. Murakami I. Suwazono S. Ogawa C. Hatano K. Utsumi H. Kawai S. Arai K. Morimoto M. Orihara K. Tamura T. Teranishi N. Hokari Y. 《Electron Devices, IEEE Transactions on》1997,44(10):1599-1603
We have determined the practical limits of cell size reduction in interline-transfer charge-coupled device (IT-CCD) image sensors, which result from diffraction occurring at the aperture above the photodiode. We have found that image cell size cannot be reduced to a level for which aperture width would fall below about 0.2 μm. We have also found, however that image cells with greater than 0.2 μm aperture size are sensitive over the entire wavelength range of visible light, and that sensitivity can be increased by thinning the photoshield film 相似文献
106.
Mutoh N. Orihara K. Kawakami Y. Nakano T. Kawai S. Murakami I. Tanabe A. Suwazono S. Arai K. Teranishi N. Furumiya M. Morimoto M. Hatano K. Minami K. Hokari Y. 《Electron Devices, IEEE Transactions on》1995,42(10):1783-1788
A newly developed 1/4-inch 380 k pixel IT-CCD image sensor features a novel cell structure in which signal charges are read out from a photodiode (PD) to a vertical-CCD (V-CCD) in a gate-assisted punchthrough mode. The cell structure, fabricated through the use of high energy ion implantation technology, enables both deep PD formation and transfer-gate (TG)/channel-stop (CS) length reduction. Deep PD formation helps increase sensitivity per PD unit area, and TG/CS length reduction widens both PD and V-CCD areas. Although the cell size is small (4.8 /spl mu/m (H)/spl times/5.6 /spl mu/m (V)), the sensor achieves both high sensitivity (35 mV/lx) and a high saturation signal (600 mV).<> 相似文献
107.
Jin-Young Kim Nozomu Uchida Katsuichi Saito Keizo Uematsu 《Journal of the American Ceramic Society》1990,73(4):1069-1073
Hot isostatic pressing (HIP) of presintered Y-TZP was studied at 1100° to 1400°C, 5 to 200 MPa, for 0.5 to 4 h. The effects of process variables of HIP and the characteristics of the presintered specimens on the densification behavior of HIP were examined. The microstructural development after HIP was also examined. Grain growth occurred during the densification in HIP. Empirically, a linear relation having a rather constant slope was found between the logarithms of porosities and grain sizes, for each starting condition. Provided this relationship was taken into account, the Ashby's model for HIP could express the densification process for this system satisfactorily. 相似文献
108.
Hiroaki Onuma Hiroaki Tanno Ai Suzuki Riadh Sahnoun Michihisa Koyama Hideyuki Tsuboi Nozomu Hatakeyama Akira Endou Hiromitsu Takaba Carlos A. Del Carpio Momoji Kubo Ramesh Chandra Deka Hiroshi Kajiyama Tsutae Shinoda Akira Miyamoto 《Journal of the Society for Information Display》2010,18(3):211-222
Abstract— Understanding the mechanism of blue‐light emission in Eu‐doped BAM phosphor as well as its sensitive degradation is required because this is a very important material in fluorescent lamps and plasma‐display panels. In this study, both theoretical and experimental investigations on the host emissions in BaMgAl10O17 and SrMgAl10O17 were performed. Host emissions from BaMgAl10O17 and SrMgAl10O17 by photoluminescence and thermoluminescence spectra were observed. Photoluminescence spectra suggested that the host emission from SrMgAl10O17 was easily quenched by thermal vibrations. The thermoluminescence spectra showed the existence of shallow and deep defect levels in BaMgAl10O17 and SrMgAl10O17 phosphors. It was shown that SrMgAl10O17 and its conduction plane could undergo degradation during irradiation of vacuum‐ultra‐violet (VUV) lights based on the calculated energy of formation of an oxygen vacancy. Moreover, the structural defects, such as oxygen vacancies, would cause localizing levels in the upper level in the valence band and in theconduction band. The results suggest the contribution of the host emission to the energy transfer to the Eu atoms would not be significant and the oxygen vacancies would act as the traps for excited carriers. 相似文献
109.
Hiroaki Onuma Itaru Yamashita Kazumi Serizawa Hiroaki Tanno Ai Suzuki Hideyuki Tsuboi Nozomu Hatakeyama Akira Endou Hiromitsu Takaba Momoji Kubo Hiroshi Kajiyama Akira Miyamoto 《Journal of the Society for Information Display》2010,18(4):301-309
Abstract— The relationship between crystal structures and emission properties has been computationally investigated for Eu2+‐doped phosphors. The electronic structure of the Eu2+‐doped BaMgAl10O17 phosphor was analyzed by using the quantum chemistry method. The different effects of O and Ba atoms on the Eu 5d states were determined. The presence of O and Ba atoms increases and decreases the energy level of the Eu 5d orbital by forming anti‐bonding and bonding interactions, respectively. According to the electronic‐structure analysis, the structure index that represents the local geometrical information of the Eu atom was defined. The relationship between the crystal structures and the emission wavelengths of the 1 6 Eu2+‐doped oxide phosphors were studied by using the quantitative structure‐property relationship (QSPR). The QSPR model suggested that the both O and alkaline‐earth atoms around the Eu atom are of importance in the determination of the emission wavelength. The interaction between the Eu and the nearest O atoms make the Eu2+ emission wavelength short. On the other hand, the interaction from the alkaline‐earth atoms around the Eu atom lengthens the Eu2+emission wavelength. This evaluation method is useful in selecting the host material that indicates a desirable emission wavelength of the Eu2+‐doped phosphors. 相似文献
110.
Keita Teranishi Padma Raghavan Jun Sun Panagiotis Michaleris 《International journal for numerical methods in engineering》2008,74(11):1690-1715
We consider the performance of sparse linear solvers for problems that arise from thermo‐mechanical applications. Such problems have been solved using sparse direct schemes that enable robust solution at the expense of memory requirements that grow non‐linearly with the dimension of the coefficient matrix. In this paper, we consider a class of preconditioned iterative solvers as a limited‐memory alternative to direct solution schemes. However, such preconditioned iterative solvers typically exhibit complex trade‐offs between reliability and performance. We therefore characterize such trade‐offs for systems from thermo‐mechanical problems by considering several preconditioning schemes including multilevel methods and those based on sparse approximate inversion and incomplete matrix factorization. We provide an analysis of computational costs and memory requirements for model thermo‐mechanical problems, indicating that certain incomplete factorization schemes can achieve good performance. We also provide empirical evaluations that corroborate our analysis and indicate the relative effectiveness of different solution schemes. Our results indicate that our drop‐threshold incomplete Cholesky preconditioning is more robust, efficient and flexible than other popular preconditioning schemes. In addition, we propose preconditioner reuse to amortize preconditioner construction cost over a sequence of linear systems that arise from non‐linear solutions in a plastic regime. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献