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排序方式: 共有1806条查询结果,搜索用时 15 毫秒
1.
2.
Shijie Zhu Yutaka Kagawa Jian-Wu Cao Mineo Mizuno 《Metallurgical and Materials Transactions A》2004,35(9):2853-2859
Time-dependent deformation in an enhanced SiC/SiC composite has been studied under constant load at high temperatures of 1200
°C, 1300 °C, and 1400 °C. Creep damage evolution was evaluated by a Young’s-modulus change of partial unloading and microscopic
observation. The addition of the glassy phase in the matrix is very effective for protecting the composite from oxidation.
The transient creep is dominant in creep life at all the temperatures. An empirical equation is proposed to describe creep
behavior of the composite. It is found that creep activation energy increases with creep time at stresses lower than matrix
cracking stress, but the activation energy remains constant at stresses higher than the matrix cracking stress. The creep
strain rate of the composite is considered to be controlled by creep of fibers based on examining the time, strain, stress,
and temperature dependencies of creep strain rates. 相似文献
3.
Hirokazu Ikeda Chikara Fukunaga Yutaka Saitoh Masahiro Inoue Junko Yamanaka 《Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment》1996,380(3):618-622
The radiation tolerance for prototype front-end chips designed for a silicon micro-strip detector was examined with a 60Co irradiation source to establish an allowable range of the radiation dose. The irradiated front-end chips were SMA2SH-64A, a 64-channel preamplifier array; SMA2SH-1, a single-channel preamplifier circuit with a comparator; and Control-C, a digital-control chip for the preamplifiers. 相似文献
4.
Yutaka Asako Hisayoshi KamikogaHisashi Nishimura Yoshiyuki Yamaguchi 《International Journal of Heat and Mass Transfer》2002,45(11):2243-2253
Compression is one solution to improve the strength of softwoods. The effective thermal conductivities of compressed Japanese cedars (cryptomeria japonica), which were compressed in the radial direction of the wood, were measured. Both the effective thermal conductivities in the tangential and fiber directions increase proportionally to the density increment due to the compression. However, the thermal conductivity in the radial direction (compression direction) increases slightly with the density increment. Numerical computations were conducted to explain the characteristics of thermal conductivity in the radial direction by using a microscopic heat conduction model for the compressed wood. The numerical results were compared with the measured values. And the physical mechanism of the heat conduction in the compressed woods is discussed. 相似文献
5.
A single loop electrochemical potentiokinetic reactivation test method has been developed for alloy 600 that produces good passivation on all the surfaces, good etching during the reactivation scan and no appreciable pitting. It is able to quantify and discriminate between samples with a wide range of degree of sensitization. The Pa value correlates well with the minimum level of chromium in the depletion regions at the grain boundaries. It has been shown that the width of the attacked regions is much larger than the width of chromium depletion regions and it does not show any direct correlation with either depth or width or with a volume parameter of chromium depletion regions. It has been shown that the chromium carbides are not attacked during the test and that the intragranular regions attacked during the test are the sites of chromium carbides in the grain matrix. A modified Pa parameter is shown to be sensitive down to 7.5 wt% chromium in the depletion regions and indicates that the intragranular carbides have shallower depletion profiles than those at grain boundaries. Comparison of the results of the single loop and the double loop tests showed a good correlation. 相似文献
6.
The effect of Zr on reduction of hardness and microstructure in an FS weld of equal channel angular-pressed Al alloy was investigated. Zr addition to Al suppressed dynamic recovery in the thermomechanically affected zone and enabled retention of the high hardness of the ECA-pressed material throughout the weld. 相似文献
7.
J Tsutsui K Kadomatsu S Matsubara A Nakagawara M Hamanoue S Takao H Shimazu Y Ohi T Muramatsu 《Canadian Metallurgical Quarterly》1993,53(6):1281-1285
Midkine (MK) and heparin-binding growth-associated molecule/pleiotrophin form a new family of heparin-binding growth/differentiation factors. We studied MK gene expression in human tumors. In normal human reference tissues, MK was highly expressed in the mucosal tissue of the small intestine, moderately in the thyroid, weakly in the tissues of the lung, colon, stomach, kidney, and spleen, and not at all in the liver. All of 6 surgically removed specimens of Wilms' tumor highly expressed MK. Also, a moderate to intense level of MK expression was noted in the majority of surgically removed hepatocellular carcinomas. The MK mRNA level was analyzed in a number of cultured and nude mice-transplanted lines of human tumors. In stomach, colon, pancreatic, lung, and esophageal carcinomas, a moderate to high level of MK expression was found in the majority of them. These results suggest an important role of MK in the development and/or biological behavior of tumors and raised a possibility to use MK as a diagnostic marker. Heparin-binding growth associated molecule/pleiotrophin mRNA was low or scarcely detectable in samples analyzed thus far except for significant levels of the expression that were observed in PA-1 teratocarcinoma cells and in some surgical specimens of Wilms' tumor. 相似文献
8.
In recent years the requirement for the reduction of energy consumption has been increasing to solve the problems of global warming and the shortage of petroleum resources. For example, in the power generation field, as thermal power generation occupied 60% of the power generation demand, considerable improvement of the thermal efficiency is required. This paper describes the pressure drop characteristics of finned tube banks used for heat exchangers in thermal power generation that were clarified by testing serrated finned tube banks with different fin heights for improved heat transfer and conventional spiral finned tube banks with different fin heights, and an equation to predict pressure drop which is necessary for the heat exchanger design is proposed. © 2006 Wiley Periodicals, Inc. Heat Trans Asian Res, 35(3): 179–193, 2006; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/htj.20112 相似文献
9.
When West meets East: Contributions of Eastern traditions to the future of psychotherapy. 总被引:1,自引:0,他引:1
Bankart C. Peter; Koshikawa Fusako; Nedate Kaneo; Haruki Yutaka 《Canadian Metallurgical Quarterly》1992,29(1):141
Discusses 2 interrelated traditions as they are reflected in contemporary and traditional approaches to psychotherapy in Japan. One uses various meditational and self-focusing instructional sets whose common goal is to facilitate the slowing down, deepening, and clearer focusing of sensory and interpersonal awareness. The 2nd tradition focuses on physical self-regulation and autonomic self-control through exercises that foster enhanced voluntary control over physical states and processes. Eastern psychology offers a set of practices that help the individual overcome the inherent selfishness of his/her isolated experience. The goals of such work include recognition of gratitude to important people in the client's life, rediscovery of the joy of meaningful work, and the experience of a unifying cosmic consciousness. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
10.
F Suzuki S Miyamoto M Takita M Oshita Y Watanabe A Kakizuka S Narumiya T Taniguchi I Muramatsu 《Canadian Metallurgical Quarterly》1997,1323(1):6-11
We attempt to determine the utility of CERAD in detecting early Alzheimer's disease (AD). CERAD battery was administered to a group of 14 control subjects, 12 patients with possible dementia prodromes and to patients with Alzheimer's disease stratified according to severity (16 mild, 8 moderate). Other measures as some subtest of the Wechsler memory scale and the Rey Complex Figure Test were also applied. Delayed recall as well as logical memory of Wechsler memory scale were found to be the best discriminators for detecting very mild cases of AD (Prodromes) (p < 0.05). None of the memory test proved of value in staging the disorder. Visuospatial functions are better determinants of the progression of the illness. Fluency also distinguish between control subjects and very mild cases. These findings suggest that delayed recall memory and probably executive function are the most useful and sensitive indicators of Alzheimer's disease. 相似文献