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141.
Nobuaki Terakado Shohei Uchida Ryusei Sasaki Yoshihiro Takahashi Takumi Fujiwara 《Ceramics International》2018,44(3):2843-2846
Chemically strengthened glass has become essential in our daily lives and the demand is rapidly increasing in a variety of fields. However, the conventional cutting process is not applicable because of its tough layer with the compressive stress. To achieve higher-throughput production of the glass, we report spatially selective weakening of the compression layer by CO2 laser scanning and provide its visualization by Raman mapping. We demonstrate cutting the scanned glass without shattering using a typical scribing wheel. Finally, we discuss the improvement in processability from the viewpoint of microscopic structures by means of thermal analysis and Raman spectroscopy. 相似文献
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Human impacts on groundwater flow and contamination deduced by multiple isotopes in Seoul City, South Korea 总被引:2,自引:0,他引:2
Hosono T Ikawa R Shimada J Nakano T Saito M Onodera S Lee KK Taniguchi M 《The Science of the total environment》2009,407(9):3189-2754
The influence of human activities on the flow system and contamination of groundwater were investigated in Seoul City, South Korea, one of the largest Asian cities, using a combination of isotopes (δD, T, δ15N, δ18O, δ34S, and 87Sr/86Sr). Eighteen representative groundwater and river water samples, which were collected over a wide area of the city, were compared with previously reported data. The distribution of stable isotopes (δD and δ18O) with groundwater potential data shows that recharged groundwater from either the surrounding mountainous area as well as the Han River and other surface streams discharged towards the northern-central part of the city, where a subway tunnel pumping station is located. It is suggested from T values (3.3 to 5.8 T.U.) that groundwater was recharged in the last 30 to 40 years. The δ34S and δ15N of SO42− and NO3− data were efficiently used as indicators of contamination by human activities. These isotopes clarified that the contribution of anthropogenic contaminants i.e., industrial and household effluents, waste landfills, and fertilizers, are responsible for the enrichment by SO42− (> 30 ppm as SO42−) and NO3− (> 20 ppm as NO3−) of groundwater. The 87Sr/86Sr values of groundwater vary (0.71326 to 0.75058) in accordance with the host rocks of different origins. Mineral elements such as Ca are also suggested to be derived naturally from rocks. The groundwater under Seoul City is greatly affected by transportation of pollutants along the groundwater flow controlled by subway tunnel pumping, contributing to the degradation of water quality in urbanized areas. 相似文献
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Wataru Natsu Yukihiro Ito Masanori Kunieda Kaoru Naoi Nobuaki Iguchi 《Precision Engineering》2005,29(1):1305
This paper describes the effects of support methods and mechanical properties of 300 mm silicon wafer on sori measurement. A new supporting method, named three-point-support method, used in the sori measurement of a large diameter silicon wafer was proposed in this study to obtain a more stable measuring process. The wafer was supported horizontally by three steel balls on the vertexes of a regular triangle at the wafer edge. The measuring repeatability and anti-disturbance ability were compared between the proposed method and the conventional one-point-support method, in which the wafer is supported with a small-area chuck at the wafer center. The effects of friction between the supports and wafer surface for the three-point-support were also estimated. Finally, the influences of different mechanical characteristics at the front and back surfaces and the crystal orientation on sori measurement were investigated. 相似文献
145.
C Takahashi Z Sheng TP Horan H Kitayama M Maki K Hitomi Y Kitaura S Takai RM Sasahara A Horimoto Y Ikawa BJ Ratzkin T Arakawa M Noda 《Canadian Metallurgical Quarterly》1998,95(22):13221-13226
A human fibroblast cDNA expression library was screened for cDNA clones giving rise to flat colonies when transfected into v-Ki-ras-transformed NIH 3T3 cells. One such gene, RECK, encodes a membrane-anchored glycoprotein of about 110 kDa with multiple epidermal growth factor-like repeats and serine-protease inhibitor-like domains. While RECK mRNA is expressed in various human tissues and untransformed cells, it is undetectable in tumor-derived cell lines and oncogenically transformed cells. Restored expression of RECK in malignant cells resulted in suppression of invasive activity with concomitant decrease in the secretion of matrix metalloproteinase-9 (MMP-9), a key enzyme involved in tumor invasion and metastasis. Moreover, purified RECK protein was found to bind to, and inhibit the proteolytic activity of, MMP-9. Thus, RECK may link oncogenic signals to tumor invasion and metastasis. 相似文献
146.
Akira Kirishima Masahiko Hirano Takayuki Sasaki Nobuaki Sato 《Journal of Nuclear Science and Technology》2015,52(10):1240-1246
For the prediction of the leaching behavior of actinide elements contained in the fuel debris that has arisen from the severe accident in Fukushima Daiichi Nuclear Power Station (NPS), a simulated fuel debris consisting of UO2–ZrO2 solid solution doped with 137Cs, 237Np, 236Pu and 241Am tracers was synthesized, and agitated leaching tests were conducted for the simulated fuel debris in seawater. The synthesized simulated fuel debris was immersed and shaken in natural seawater collected at a coast 11 km away from Fukushima Daiichi NPS. The brief leaching test conditions were T = 25 °C and solid–liquid ratio = 4 g/l, and the test duration was up to 31 days. The ratio of tracers leached into seawater from the simulated fuel debris by the agitated leaching test for 4 days was evaluated to be 0.09% for U, 0.01% for Np, 0.01% for Pu, 0.01% for Am and 35.39% for Cs by the α or γ spectrometry of the soluble fraction. The leaching of actinides from the real fuel debris in reactor units 1–3 in Fukushima Daiichi NPS is expected to be suppressed in comparison with that from normal light water reactor spent fuel. 相似文献
147.
Shin‐ichi Hirashima Ryoga Arai Kosuke Nakashima Nobuaki Kawai Junko Kondo Yuji Koseki Tsuyoshi Miura 《Advanced Synthesis \u0026amp; Catalysis》2015,357(18):3863-3867
For the asymmetric hydrophosphonylation of aldehydes, an efficient organocatalytic approach with a diaminomethylenemalononitrile‐based hydrogen‐bonding donor catalyst is presented. The catalyst induces high yields and excellent enantioselectivities (up to 98% yield, 96% ee).
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We studied a flexible optical disk (FOD) system comprising a flexible disk and stabilizer. We improved the stabilizer system based on our previous design: a triangularlly arranged stabilizer system. The part that was improved was the arrangement of the stabilizers; we made them asymmetrically. We experimentally demonstrated that the asymmetrical design effectively controls the aerodynamic stabilization at a pickup focal point. The suppressed axial runout we actually evaluated at the focal point was less than 10 µm at a rotational speed from 1,000 to 7,000 and at radii from 35 to 50 mm. The asymmetrical effect corresponded well with the pressure field calculated using a coupled analysis, which combined a fluid and structural analysis. 相似文献