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151.
Zhanpeng Lu Tetsuo Shoji Yoichi Takeda Yuzuru Ito Seiya Yamazaki 《Corrosion Science》2008,50(3):698-712
The stress corrosion cracking (SCC) growth rate of a warm-rolled (WR) 316L stainless steel contoured double cantilever (CDCB) specimen was measured in high purity water at various temperatures and under various loading patterns. An alternating current potential drop (ACPD) technique was used to monitor the crack growth kinetics throughout the tests. The fracture surface exhibited typical intergranular SCC characteristics. Depending on the test conditions, three kinds of crack growth kinetics, i.e., increasing with time then becoming steady, being constant during the whole period, decreasing with time then becoming steady, were identified and are described. The steady state crack growth rate (CGR) values are used to quantify the effects of the loading pattern and the environmental temperature. A moderate increase in the crack growth rate was encountered by employing periods of unloading and reloading to form a trapezoidal loading pattern and the enhancement factor was found to depend on the holding time and the times for unloading and reloading. It was found that the crack growth is thermally activated; however, the apparent activation energy is not constant but seems to be greater at higher temperatures. Several types of temperature-dependent crack growth kinetics are proposed based on the rate-determining step for the crack growth. The present experimental results can be rationalized by considering multiple element processes such as aqueous mass transport and solid-state mass transport in the crack growth. The cracking mode, the temperature dependence of the crack growth rate, and the transient crack growth behavior for WR 316L SS after changing the environmental temperature are quite similar to those for a cold-worked(CW) 316L SS tested in the same environment, despite their different absolute crack growth rate values. The effect of yield strength on CGR is more significant at lower temperatures and the apparent activation energy for the crack growth rate seems to be lower in the material with a higher yield strength. Time-lag crack growth behavior was found at points during several test steps on WR 316L SS, for example, just after in situ pre-cracking and after increasing or decreasing the temperature, which is quite consistent with the results obtained with CW 316L SS. The importance of in situ monitoring of the crack growth for obtaining steady state crack growth rates is emphasized, especially for those steps for which a nonlinear crack growth period occurs after changing the test condition. 相似文献
152.
A lacquer hybridized with an organic silane compound has been synthesized, and the reaction mechanism between the urushiol and organic silane has been evaluated based on IR, NMR, TGA, and DSC measurements. 相似文献
153.
Shin’ichi Konno Shigeo Kazama Maki Hiraoka Hirokazu Sakamoto Kenji Mizoguchi Hiromi Taniguchi Toshikazu Nakamura Kou Furukawa 《Journal of Low Temperature Physics》2006,142(3-4):621-624
β′-(BEDT-TTF)(TCNQ) is a compound of BEDT-TTF (=ET) and TCNQ molecules aligned orthogonally with each other, forming two-dimensional
sheets and one-dimensional columns of 1/4-filled π band, respectively. It is known that the metal-insulator transition occurs
at 330 K at ambient pressure. We have measured the electronic spin susceptibility by means of the EPR-NMR method at 50 MHz,
and the angular dependence of g-factor and line width of EPR both at Q (34 GHz) and W (94 GHz) band. We successfully confirmed
that the antiferromagnetic transition occurs in ET sheets and TCNQ columns, independently. 相似文献
154.
Flexural test specimens were injection-molded from polypropylenes added with 0.5 wt % of calcium carbonate, talc, p-tert- dibutyl-benzoic acid monohydroxy aluminum, or p-di-methyl-benzylidene sorbitol under cylinder temperatures of 200–;320°C. Properties such as flexural modulus, flexural strength, heat distortion temperature, Izod impact strength, hardness, and mold shrinkage and higher-order structures such as crystalline texture, crystallinity, a*-axis-oriented component fraction, and degree of crystalline orientation were measured and structure–property relationships were studied. By the addition of crystallization nucleators, the flexural modulus, flexural strength, heat distortion temperature, hardness, and mold shrinkage were increased and Izod impact strength was decreased. The degrees of crystalline orientation such as the orientation fraction OF and c-axis orientation function fc were increased by the addition of nucleators. The degree of the increase was higher as the crystallization temperature was higher. Close relationships were observed between some properties and the degrees of crystalline orientation. 相似文献
155.
Application of principal-component analysis on near-infrared spectroscopic data of vegetable oils for their classification 总被引:3,自引:0,他引:3
Tetsuo Sato 《Journal of the American Oil Chemists' Society》1994,71(3):293-298
In the near-infrared (NIR) spectra of oil, information about fatty acid composition is concentrated in the range of 1600–2200
nm. Principal-component analysis (PCA) was applied on the standardized full NIR spectral data of this region for vegetable
oils to totally capture the NIR spectral pattern. Nine varieties of vegetable oils (soybean, corn, cottonseed, olive, rice
bran, peanut, rapeseed, sesame and coconut oil) could be successfully classified from their PCA scores. Examining the contribution
of wavelengths to PCA scores showed that wavelengths with a high loading weight were assigned to characteristic absorption
regions that correspond to specific fatty acid moieties. This classification is related to the fatty acid composition of an
oil, and it can be carried out rapidly and easily after eigenvectors were obtained. 相似文献
156.
Tetsuya Yamamoto Azamat Zhumagazin Takuma Furusawa Ryoji Tanaka Tetsu Yamakawa Yohei Oe Tetsuo Ohta 《Advanced Synthesis \u0026amp; Catalysis》2014,356(17):3525-3529
Cyclometallated NHC palladium complexes prepared from palladium(II) acetate [Pd(OAc)2] and unsymmetrical 1,3‐diarylimidazolinium salts catalyzed the hydroxymethylation of (hetero)arylboronic acids using an excess amount of formalin to afford (hetero)arylmethanols in good to satisfactory yields.
157.
For the Mg-Sn-Al alloys, the ultimate strength (UTS) of an extruded Mg-9wt.%Al-2wt.%Sn alloy reached 390 MPa. TEM observation indicated that plate-like Mg17Al12 precipitates having Burgers orientation relationship with the matrix are responsible for the strength. This alloy also exhibits an age hardening behavior: the peak hardness appears after 15-20 h of heat treatment at 473 K. On the other hand, the UTS of the Mg-Mg-Sn-Zn alloys are on the order of 300 MPa. The precipitates in these alloys are composed of the Mg2Sn and MgZn2 particles. It was found that these phases often precipitate together, suggesting that the MgZn2 phase can act as a nucleation sites for Mg2Sn. 相似文献
158.
Tetsuo Munakata Satoshi Someya 《International Journal of Heat and Mass Transfer》2004,47(21):4525-4533
Melt flow structure during the silicon single crystal growth process strongly affects the crystal quality. Therefore, melt convection control technique should be developed to obtain the high quality single crystal. For this purpose, we proposed a high frequency magnetic field applied method, and numerically investigated the effect of high frequency magnetic field on Czochralski (CZ) silicon melt convection. The results revealed that the melt convection was strongly affected by the applied electric current and frequency. The temperature distribution just below the crystal became flat if the applied electric current and frequency were selected as optimized value. 相似文献
159.
Kei Nishikawa Yasuhiro Fukunaka Tetsuo Sakka Yukio Ogata J. Robert Selman 《Journal of power sources》2007
The charging (lithiation) and discharging (delithiation) of a Ni–Sn alloy electrode was examined by means of holographic interferometry and laser scanning confocal microscopy (LSCM). The developing concentration profile of Li+ ion during discharging (delithiation) of the Ni–Sn alloy electrode agreed reasonably well with the prediction based on transient diffusion theory, indicating that the cell configuration successfully suppressed natural convection due to the electrochemical reaction. The morphological variation of Ni–Sn alloy electrode during charge/discharge cycle could be observed very clearly by in situ LSCM. It was found that the contraction of active material during the discharge (delithiation) initiates cracks in the Ni–Sn alloy electrode. 相似文献
160.
Michio Yamawaki Tetsuo Nishihara Yoshiyuki Inagaki Kazuo Minato Hiroyuki Oigawa Kaoru Onuki Ryutaro Hino Masuro Ogawa 《International Journal of Hydrogen Energy》2007
It is universally admitted that hydrogen is one of the best energy media and its demand will increase greatly in the near future. However, little hydrogen exists naturally, so that how to generate hydrogen without bringing forth much CO2 will be very important research subject. Hydrogen generation from water using nuclear energy is one of the solutions for this problem. Especially, the high temperature gas cooled reactor (HTGR) has a possibility to generate hydrogen economically compared with other types of nuclear reactors. As for long-lived radioactive waste to be generated by nuclear reactors, it is expected to significantly reduce its burden to the human environment by applying transmutation technologies. This report describes the feature of the hydrogen generation with HTGR and the development of the accelerator-driven subcritical system to reduce radioactive waste ongoing at JAEA. 相似文献