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131.
Zhenxiang Cheng Kiyoshi Ozawa Minoru Osada Akimitsu Miyazaki Hideo Kimura 《Journal of the American Ceramic Society》2006,89(4):1188-1192
We have demonstrated a synthetic procedure for nano-sized NaNbO3 powder and its thin films using a carbon-free precursor prepared by the reaction of H2 O2 with sodium and niobium alkoxides. A combination of X-ray powder diffraction, Raman spectra, and thermal gravity and differential thermal analysis, carbon analysis, fourier transform infrared spectra, transmission electron microscopy, and atomic force microscopy was used to characterize the resulting materials and precursor compounds. Results show that this procedure demonstrates the major advantages of low-temperature synthesis (∼400°C) and low weight loss during transformation into NaNbO3 because of its carbon-free nature, which also provides the option of preparing nano-sized particles and dense, crack-free NaNbO3 thin films. 相似文献
132.
Ping Shen Hidetoshi Fujii Taihei Matsumoto Kiyoshi Nogi 《Metallurgical and Materials Transactions A》2004,35(2):583-588
The reactive wetting behavior of SiO2 substrates by molten Al was investigated at temperatures between 800 °C to 1250 °C in a purified Ar-3 pct H2 atmosphere of about 0.11 MPa using an improved sessile drop method. The time dependence of the changes in contact angle and
droplet geometry was monitored and the wetting kinetics was identified. The initial equilibrium or quasi-equilibrium contact
angles are generally larger than 90 deg and do not significantly vary with temperature. The subsequent remarkable decrease
in the contact angle mainly results from the progressive decrease in the droplet volume rather than the advance of the solid-liquid
interfacial front. The significant effect of temperature on the wetting kinetics is essentially related to its effect on the
reaction and molten Al penetration progress. For systems with a considerable decrease in the droplet volume during reactive
wetting, a criterion for evaluation of the true wetting improvement was proposed. 相似文献
133.
Kiyoshi Kemmochi Hiroshi Takayanagi Chohachiro Nagasawa Jun Takahashi Ryuichi Hayashi 《Advanced Performance Materials》1995,2(4):385-394
It becomes significantly important to preserve ecological balance of the earth and protect the environment from getting worse. One of the urgent issues to be tackled will be to develop and establish recycling technology for polymeric composite materials. The expression of recycling technology in this case is that after the life of industrial products of fiber reinforced thermoplastic (FRTP) is completed, instead of being thrown away as wastes, they are reused as a raw material for new applications. An additional goal is that of saving valuable resources and not consuming further energy. This paper deals with a possibility of closed-loop recycling technologies for FRTP. The key factor is the fiber length which is expected to reduce in each recycling step. Materials tested here are continuous FRTPs, long FRTPs, short FRTPs, and powder reinforced plastics. The effect of fiber length on the reinforcing mechanism is first examined. The correlation between outdoor exposure test and accelerated weathering test is the second subject to covered. The third subject is to make clear the influence of crushing and heat history which are inevitable during each recycling stage. Throughout the above investigation, the concept of closed-loop recycling technologies has been established, although it is still in a preliminary stage.Abbreviations FRTP
fiber reinforced thermoplastic
- C-, L-, S-, P-FRTP
continuous-, long-, short-FRTP, powder-RTP
- FRP
fiber reinforced thermosetting plastic
- UD
unidirectional
- PP
polypropylene
- CF
carbon fiber
- GF
glass fiber
-
V
f
volume fraction of fiber 相似文献
134.
Triethoxysilyl‐modified polychloroprene (CR) latex was synthesized by the emulsion copolymerization of 2‐(3‐triethoxysilylpropyl)‐1,3‐butadiene with chloroprene. This latex was mixed with unmodified CR latex and tetraethoxysilane to obtain CR–silica composites by sol‐gel reaction in the latex. SEM observation showed that the silica particles in unvulcanized composites have various diameters ranging from 0.1 to 0.6 μ m, and their size became larger with the decrease of the silica content. Vulcanized CR–silica composites showed that the tensile modulus and tear strength improved with an increase of the amount of modified CR. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 1545–1552, 2005 相似文献
135.
Kiyoshi Ohishi Toshimasa Miyazaki Koichi Inomata Daiichi Koide Haruki Tokumaru 《Electrical Engineering in Japan》2006,156(4):60-68
This paper proposes a new robust feedforward tracking servo system for optical disk recording systems in the case of a sudden disturbance for the optical disk recording system. In optical recording systems, the tracking servo system must suppress tracking error below its tolerance. This paper designs the robust feedback control system by using the coprime factorization and disturbance observer. The proposed robust feedback control system suppresses the sudden disturbance caused by walking and running. The detecting signal of optical disk recording systems is only a tracking error. Hence, the feedforward controller of the proposed tracking control system is constructed based on both Zero Phase Error Tracking (ZPET) control theory and prediction of tracking error. The experimental results point out that the proposed tracking servo system has a quick and precise tracking response and keeps the residual tracking error below its tolerance. © 2006 Wiley Periodicals, Inc. Electr Eng Jpn, 156(4): 60– 68, 2006; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20257 相似文献
136.
Hideki Hyuga Kiyoshi Hirao Mark I. Jones Yukihiko Yamauchi 《Journal of the American Ceramic Society》2003,86(7):1081-1087
Si3 N4 /carbon fiber composites were fabricated using several types of fiber. All the composites had higher fracture toughness compared with monolithic Si3 N4 ceramics. Tribological properties were investigated by a ball-on-disk method under unlubricated conditions. The composite containing fibers with a high orientation of graphite layers and high graphite content indicated a low friction coefficient. It was identified, by Raman spectroscopy, that graphite was transferred from the composite to the Si3 N4 ball of the counterbody during the wear test. This transferred layer was effective for producing the low friction behavior of the composite. 相似文献
137.
138.
139.
Kanai Hiroshi Yamano Eiki Nakayama Kiyoshi Kawamura Naoshige Furuhata Hiroshi 《IEEE transactions on bio-medical engineering》1974,(2):144-151
A new induction flowmeter which can measure the blood flow from the skin surface is discussed theoretically and experimentally. A pair of electrodes placed on the skin detect the EMF induced by the interaction of the blood flow and a magnetic field applied from outside the skin. The relation between the EMF and the flow rate, which is obtained theoretically, is also confirmed experimentally within the error of 10 percent. 相似文献
140.
Kiyoshi Ishii 《Structural Safety》1986,4(2)
This paper describes a stochastic finite element method using the first-order approximation at a failure point of a set of random variables. The method is extended to equivalent normal represtation of non-normal distributions and offers two advantages: (1) It gives a consistent measure of failure probability for the limit-states defined in terms of different but equivalent performance function formulations, (2). It can be applied to reliability analysis for non-normal variants. Results using this method are compared favorably with that of Monte Carlo simulation in a simple example. Furthermore, this method will be applied to earth slope stability analysis to give probability levels for local and global failures on a potential failure surface. 相似文献