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51.
Niinomi M Wang L Enjitsu T Fukunaga K 《Journal of materials science. Materials in medicine》2001,12(3):267-272
In order to investigate the effect of molecular weight on fatigue characteristics in the ultra high molecular weight polyethylene (UHMWPE), tension–tension fatigue tests of notched specimens were carried out in the present study. The effects of frequency and stress ratio on the fatigue characteristics were also investigated and fractography was discussed. The fatigue strength does not increase with increasing molecular weight. The fatigue strength might be influenced by the high degree of crystallinity in spite of the decreased tie molecule density in this study. Almost no effect of frequency on the number of cycles to failure can be observed. However, the higher the frequency, the higher the crack tip temperature. The effects of heat and strain rate on the fatigue strength must be considered in polymer materials. At a high stress ratio, the stress–number of cycles to failure (S–N) curves shift to high number cycles to failure side. Both stress amplitude and mean stress influence the fatigue life of UHMWPE. © 2001 Kluwer Academic Publishers 相似文献
52.
Seiichi Takami Teruyuki Sato Tahereh Mousavand Satoshi Ohara Mitsuo Umetsu Tadafumi Adschiri 《Materials Letters》2007,61(26):4769-4772
We synthesized surface-modified iron oxide nanoparticles in aqueous phase by heating an aqueous solution of iron sulfate (FeSO4) at 473 K with a small amount of either n-decanoic acid (C9H19COOH) or n-decylamine (C10H21NH2), which is not miscible with water at room temperature. Transmission electron microscopy showed that the addition of n-decanoic acid or decylamine changed the shape of the obtained nanoparticles. X-ray diffraction spectra revealed that the synthesized nanoparticles were in α-Fe2O3 or Fe3O4 phase while Fourier transform infrared spectroscopy and thermogravimetry indicated the existence of an organic layer on the surface of the nanoparticles. In the synthetic condition, decreased dielectric constant of water at higher temperature increased the solubility of n-decanoic acid or n-decylamine in water to promote the reaction between the surface of iron oxide nanoparticles and the organic reagents. After the synthesis, the used organic modifiers separated from the aqueous phase at room temperature, which may help the environmentally benign synthesis of surface-modified metal oxide nanoparticles. 相似文献
53.
Shozo Miyazaki Akie Takahashi Kunihiko Itoh Mariko Ishitani Masatake Dairaku Mitsuo Togashi 《Drug development and industrial pharmacy》2013,39(7):780-787
Background: Oral sustained release gel formulations may provide a means of administering drugs to dysphagic and geriatric patients who have difficulties with handling and taking oral dosage forms. Aim: We have designed gel formulations for the oral administration of paracetamol with suitable rheological characteristics for ease of administration to patients with swallowing difficulties and sufficient integrity in the acidic environment of the stomach to achieve a sustained release of this drug. Method: Gels formed by gelatin, agar, gellan, pectin, and xyloglucan were assessed for suitable gel strength and in vitro and in vivo release characteristics. Results: Gellan (1.5%?w/v) and xyloglucan gels (1.5%?w/w) had acceptable gel strengths for ease of swallowing and retained their integrity in the rat stomach sufficiently well to sustain the release of paracetamol over a period of 6 hours. Comparison of 1.5%?xyloglucan gels with a commercially available preparation with identical paracetamol concentrations demonstrated improved sustained release properties of the xyloglucan gels. Conclusions: Gels formed by gellan and xyloglucan have suitable rheological and sustained release characteristics for potential use as vehicles for oral delivery of drugs to dysphagic patients. 相似文献
54.
Haruyoshi Otobe Mitsuo Akabori Kazuo Minato 《Journal of the American Ceramic Society》2008,91(6):1981-1985
The oxygen potentials of AmO2− x were measured in the x range of 0.01–0.5 and the temperature range of 1000–1333 K by the electromotive force method. The oxygen potentials at 1333 K were −19.83 kJ/mol for x =0.019 and −319.1 kJ/mol for x =0.485, which were higher than those of CeO2− x by approximately 200 kJ/mol for the corresponding x values. From the dependence of the oxygen potentials on x and temperature, a tentative phase diagram of Am–O system was proposed, which suggested the presence of the intermediate phases of Am7 O12 and Am9 O16 in the Am–O system. 相似文献
55.
Hasegawa Tatsuro Yamauchi Hisashi Sashida Yoshio Matsumoto Mitsuo 《Industrial Electronics, IEEE Transactions on》1985,(3):253-260
Recent application of distributed control systems to large-and medium-scale industrial plants requires effective and high-speed communication among the control devices each other to ensure high-performance operation. 相似文献
56.
Yoshiharu Hatakeyama Mitsuo Umetsu Masahiro Minami Satoshi Ohara Seiichi Takami Tadafumi Adschiri 《Journal of Materials Science》2008,43(7):2426-2430
The DNA, which forms a double helical conformation by the highly selective base-pairing rule with the width of 2 nm, is one
of the polymers utilized as a template for nanoparticle assembly. Then, holiday junction structure, where two different DNA
double strands intersect and replace each complement strand, is an important artificial motif for forming two-dimensional
mesh-like DNA morphology. In this study, the two-dimensional sheet with the mesh-like conformation is formed and the growth
of the DNA morphology is controlled by changing the temperature in the formation process. The influence of the cooling procedure
on the formation process of the two-dimensional DNA sheet is observed by atomic force microscope, and the formation of double
strands in the process is traced by absorption spectra. The spectroscopic results demonstrate that the two-dimensional DNA
sheet is strongly dependent on the correlation between the applied cooling process and the melting temperature of double helical
conformation, and that the growth of the two-dimensional DNA sheet can be manipulated by the cooling procedure. Further, we
will show the size control of the DNA sheet by mixing the designed DNA which inhibits the growth of the DNA sheet. 相似文献
57.
An experimental evaluation of spatial distribution for deeply penetrating protons in carbon material
Mitsuo Tosaki Daisuke Ohsawa Yasuhito Isozumi 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2005,230(1-4):59-62
The peak profile of the 4.8-MeV resonance by the 12C(p,p)12C reaction in backscattering geometry has been analyzed to examine two kinds of stragglings of proton, i.e. the depth straggling in the incoming path and the energy loss straggling in the outgoing path. The analysis, which is combined with existing theoretical treatments for the stopping process and the energy loss straggling, has made it possible to deduce the penetration depth and its spread at the resonance position in carbon materials. The present method, as a new tool for direct inspection of ion beams inside target material, is explained in detail. 相似文献
58.
Mok-Ryeon Ahn Shigenori Kumazawa Yumiko Usui Jun Nakamura Mitsuo Matsuka Fang Zhu Tsutomu Nakayama 《Food chemistry》2007,101(4):1383-1392
Propolis is a resinous substance collected by honeybees from various plant sources. The composition of propolis depends on time, vegetation, and the area of collection. This study examined the antioxidant activity of propolis from various areas of China: Heilongjiang, Neimongol, Hebei, Shandong, Shanxi, Gansu, Henan, Hubei, Sichuan, Hunan, Yunnan and Hainan. Ethanol extracts of propolis (EEP) were prepared and evaluated for their antioxidant activities by β-carotene bleaching, 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical-scavenging, and 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) radical cation decolorization assays. Furthermore, the major constituents in EEP were identified by high-performance liquid chromatography (HPLC) analysis with a photodiode array (PDA) and mass spectrometric (MS) detection, and each component was quantitatively analyzed. All propolis samples except that from Yunnan had relatively strong antioxidant activity accompanied by high total polyphenol contents. Propolis with strong antioxidant activity contained large amounts of antioxidative compounds, such as caffeic acid, ferulic acid and caffeic acid phenethyl ester. On the other hand, propolis from Yunnan and Hainan had compounds not present in propolis from other areas. 相似文献
59.
Linear programming is one of the most widely used Operations Research/Management Science techniques. Recently, multiple objective decision making has been well established as a practical approach to seek a satisfactory solution to a decision making problem. Much attention has been focused on a microcomputer as an economical management tool.
In this paper we propose an interactive goal attainment method using the eigenvector algorithm for solving a multiple objective linear programming problem interactively on microcomputers. In the software package Micro-LPS based on the method proposed, we design a conversational and user-friendly system in which the user commands are involved. 相似文献
60.
Mitsuo Fukuda 《Microelectronics Reliability》2000,40(1):27
The failure modes and failure mechanisms in optoelectronic devices, such as laser diodes, Light-emitting diodes, and photodiodes, are reviewed through a historical overview of device reliability and their future reliability is briefly discussed. 相似文献