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101.
Masahiro Kitada 《Journal of Materials Science》1980,15(7):1684-1690
Microstructures of damaged layers near the abraded surface of GaP, GaAs0.6P0.4 and GaAs single crystals have been observed with a transmission electron microscope. The damage due to 0.3 m Al2O3 abrasion consists of dislocations. Dislocation densities in the abrasion band and other regions are larger than 5×1011 cm–2 and about 1011 cm–2, respectively. Dislocation density decreases with increasing distance (depth) from the abraded surface. The depths of the damage layers for GaP, GaAs0.6P0.4 and GaAs are about 0.4, 0.55, and 0.8 m, respectively. The Burgers vector of dislocations is a/2[1 1 0], and A and B dislocations are observed. During annealing, the dislocations are rearranged and eliminated by the reaction of the dislocations with different Burgers vectors and climbing motion. The rearrangement temperatures for dislocations in GaP and GaAs are about 500 and 450° C, respectively. Electrical resistance changes in the damaged layer of GaP are recognized by electrical resistance measurements. 相似文献
102.
Akira Nakayama Shinji Nambu Masahiro Inagaki Masahiko Miyauchi Nobuyuki Itoh 《Journal of the American Ceramic Society》1996,79(6):1453-1456
Complex permittivity of polycrystalline AlN was measured over the frequency range 100 MHz to 13 GHz using reflection coefficient and cavity resonator methods. Dielectric relaxation peaks of loss tangent were observed in the frequency range 200 MHz to 3 GHz. The maximum value of loss tangent was ∼200 × 10−4 . Relative permittivities decreased by ∼4% with increased frequency at the region of relaxation peaks. It was shown that these dispersion frequencies were inversely proportional to the grain sizes of AlN and independent of purities and processes. Model calculations for elastic vibration of a single-crystal grain of AlN were performed to investigate the origin of the dielectric dispersion due to piezoelectric effect. The calculated results of elastic sphere and 14-faced-polyhedron models showed a good quantitative agreement with the observed dispersion frequencies, which suggested that the dispersion was due to a piezoelectric vibration of a single grain of AlN ceramics at microwave frequencies. 相似文献
103.
Kenichi Noguchi Yukihisa Matsuda Manabu Oishi Takaki Masaki Sadao Nakayama Masahiro Mizushina 《Journal of the American Ceramic Society》1990,73(9):2667-2676
Tensile strength of Y2 O3 -stabilized ZrO2 polycrystals (Y-TZP) was measured by a newly developed tensile testing method with a rectangular bar. The tensile strength of Y-TZP was lower than that of the three-point bend strength, and the shape of the tensile strength distribution was quite different from that of the three-point bend strength distribution. It was difficult to predict the distribution curve of the tensile strength using the data of the three-point bend strength by one-modal Weibull distribution. The distribution of the tensile strength was analyzed by two- or three-model Weibull distribution coupled with an analysis of fracture origins. The distribution curve of the three-point bend strength which was estimated by multimodal Weibull distribution agreed favorably with that of the measured three-point bend strength values. A two-modal Weibull distribution function was formulated approximately from the distributions of the tensile and three-point bend strengths, and the estimated two-modal Weibull distribution function for the four-point bend strength agreed well with the measured four-point bend strength. 相似文献
104.
The tracer diffusivities of calcium and iron in a steel-making slag of 33 pct CaO-27 pct SiO2-40 pct Fe2O3 by charge composition have been measured at 1360 to 1460°C as a function of temperature and oxygen pressure in the gas phase. The results expressed in cm2/s (in SI unit of m2/s, the following equation should be divided by 10,000) are given by $$D^{tr} = D_0 \left[ {P_{O_2 } } \right]^{1/\chi } \exp \left[ { - \frac{E}{{RT}}} \right](at 1360 to 1460^\circ C)$$ where for tracer diffusion of iron, Do is 0.2,x is 8.5, andE is 26 kcal/mol (1.09 x 104 J/ mol) and for tracer diffusion of calcium, Do is 0.1,x is 12.5, andE is 28 kcal/mol (1.17 × 104 J/mol). Prior to diffusion runs, the slag was equilibrated with the gas mixture of carbon monoxide and dioxide with an oxygen pressure of 10?11 to 10?8 atm. The diffusivity was measured by the instantaneous plane source method, using radioactive tracers of calcium and iron. The increase of the tracer diffusivities with the oxygen pressure was interpreted in relation to a probable increase of the divalent cation vacancies in the slag. 相似文献
105.
Ternary oxide mixtures of lime, alumina, and silica were premelted and quenched to produce glassy cylinders. A diffusion couple was selected from the mixtures of six different compositions in such a way that the average composition could be 40 wt pct CaO-20 wt pct A12O3 = 40 wt pct SiO2. Penetration curves of the components were measured with a X-ray microprobe analyzer. The interdiffusivities matrix defined with the Matano interface has been obtained from 52 successful diffusion runs at 1723 K to 1823 K as follows; 1 $$\begin{gathered} \tilde D_{10 - 10}^{30} = 8.9 \times 10^{ - 11} \exp ( - \frac{{253,700}}{{RT}})(m^2 /s) \hfill \\ \tilde D_{10 - 20}^{30} = - 2.5 \times 10^{ - 11} \exp ( - \frac{{194,300}}{{RT}})(m^2 /s) \hfill \\ \end{gathered} $$ 2 $$\begin{gathered} \tilde D_{20 - 10}^{30} = - 4.0 \times 10^{ - 11} \exp ( - \frac{{177,600}}{{RT}})(m^2 /s) \hfill \\ \tilde D_{20 - 20}^{30} = 6.12 \times 10^{ - 11} \exp ( - \frac{{318,400}}{{RT}})(m^2 /s) \hfill \\ \end{gathered} $$ where symbols, 10, 20, and 30 mean CaO, A12O3, and SiO2, respectively, and the activation energies are in Joules per mole. The diffusion composition paths obtained are discussed in relation to Cooper’s parallelogram. The composition dependency of the above interdiffusivities is estimated from the quasibinary interdiffusivities in all composition ranges of the present oxide system in liquid state. 相似文献
106.
107.
T. Goto N. Wakamatsu H. Kamemizu M. Iijima Y. Doi Y. Moriwaki 《Journal of materials science. Materials in medicine》1991,2(3):149-152
The sintering mechanism of hydroxyapatite (HAp) by addition of lithium phosphate (Li3PO4) has been investigated. Using the X-ray diffraction method, HAp was confirmed to decompose into -Ca3(PO4)2 (-TCP) by addition of Li3PO4. The measurement of shrinkage rate by the isothermal firing made it clear that the densification process at the initial stage of sintering took place in the presence of liquid phase. Furthermore, the examination of the phase diagram on the binary system -TCP-Li3PO4 revealed that there was an eutectic point at 1010°C in the composition of 60 wt% Li3PO4. From these evidences, we concluded that -TCP produced by the decomposition of a part of HAp has formed the liquid phase by reacting with Li3PO4 above 1010°C, and that this liquid phase has largely promoted the densification by the rearrangement of HAp particles at the initial stage of sintering. 相似文献
108.
Allinson M Kageyama S Nakajima D Kamata R Shiraishi F Goto S Salzman SA Allinson G 《Water science and technology》2012,66(4):768-774
In 2007, samples of treated effluent were collected at point of discharge to the environment from 39 wastewater treatment plants (WWTPs) located across Victoria, Australia grouped by treatment type. Sample genotoxicity was assessed with a high-throughput luminescent umu test method using Salmonella typhimurium TL210 strain, with and without addition of a commercially available metabolic activation system. Samples were also screened using a gas chromatographic-mass spectrometric mass-structure database recognition method. A genotoxic response was observed in half of the samples tested without metabolic activation system (相似文献
109.
Shunjiro Ogawa Hideyo Suzuki Masatake Toyoda Yoshio Ito Masahiro Iwaida Hiroko Nonogi Tazu Fuke Kazuo Obara Tadao Adachi Koichi Fujita Makiko Ikuzawa Tetsuo Izumi Takashi Hamano Yukimasa Mitsuhashi Yukio Matsuki 《Zeitschrift für Lebensmitteluntersuchung und -Forschung A》1979,168(4):293-298
Summary Detection and determination of traces of sulphites in foods was attempted by use of the modified Rankine apparatus and pararosaniline colorimetry. Replacement of alkaline titration reported previously by pararosaniline colorimetry lowered the absolute detection limit from 30 g (titration method) to 2 g. In view of clean analysis, in the color developing system, 0.1 N-sodium hydroxide was used in place of mercuric chloride solution commonly used as an absorbant of sulphites. In order to prevent oxidative decomposition of sulphites during operation, nitrogen gas was used as carrier instead of air. Dimedone and sodium azide were used for the elimination of aldehydes and nitrites, respecitvely, in the sample, which will disturb the color development of sulphites with pararosaniline-formaldehyde reagents. With this improved method, it was possible to determine the residual sulphites in frozen peeled shrimps, sugared beans and other foods with low sulphite contents accurately.
Studies on the Analyses of Sulphites in Foods (IV) 相似文献
Colorimetrische Mikrobestimmung von Sulfiten in Lebensmitteln bei Anwendung der modifizierten IV. Rankine Apparatur
Zusammenfassung Geringe Sulfitmengen in Lebensmitteln (geschälte Garnelen, gezuckerte Bohnen) können colorimetrisch bestimmt werden. Die neuentwickelte Methode beruht auf einer Kombination von colorimetrischer Bestimmung mittels p-Rosanilin und der Bestimmungsmethode nach Rankine. Auf diese Weise lassen sich Gehalte von 2 g noch genau bestimmen. Bei der Farbentwicklung wurde das giftige Quecksilbertetrachlorid durch 0.1 n-NaOH ersetzt, anstelle von Luft Stickstoff als Trägergas verwendet und somit eine Oxydation des Sulfits während der Bestimmung vermieden. Da Nitrit und Aldehyde die Farbentwicklung stören, wurde ihr Einfluß durch Dimedon und Natriumazid ausgeschaltet.
Studies on the Analyses of Sulphites in Foods (IV) 相似文献
110.
Atsunori Matsuda Yugo Higashi Kiyoharu Tadanaga Masahiro Tatsumisago 《Journal of Materials Science》2006,41(24):8101-8108
SiO2–TiO2 spherical microparticles of about 0.7 μm in diameter were prepared by the sol–gel method. Anatase nanocrystals were formed in the microparticles and their specific surface area was increased after a hot-water treatment at 90 °C. From the changes in the concentration of I2 photocatalytically generated from KI aqueous solution, the activity of the SiO2–TiO2 microparticles was found to increase with increasing the hot-water treatment time. Particulate, thick films were electrophoretically deposited on indium tin oxide (ITO)-coated glass substrates using the anatase nanocrystal-precipitated SiO2–TiO2 microparticles. The thickness of the electrophoretically deposited particulate film increased to be approximately 10 μm with an increase in applied voltage. The resultant thick film showed a high photocatalytic activity. 相似文献