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排序方式: 共有415条查询结果,搜索用时 15 毫秒
11.
Tomoko Okuyama Jun Shirakawa Kazuki Tajima Yoko Ino Heidrun Vethe Yu Togashi Mayu Kyohara Ryota Inoue Daisuke Miyashita Jinghe Li Nozomi Goto Taiga Ichikawa Shingo Yamasaki Haruka Ohnuma Rie Takayanagi Yayoi Kimura Hisashi Hirano Yasuo Terauchi 《International journal of molecular sciences》2020,21(21)
12.
Effects of aging on poly(1‐trimethylsilyl‐1‐propyne) membranes irradiated with vacuum ultraviolet radiation for gas separation 下载免费PDF全文
Tetsuro Yoshioka Yoshiki Miyashita Taichi Motoo Kentaro Saito Kazukiyo Nagai 《应用聚合物科学杂志》2018,135(11)
In this study, we investigated the effects of physical aging on the surface and gas‐transport properties of highly gas permeable poly(1‐trimethylsilyl‐1‐propyne) membranes irradiated with vacuum ultraviolet (VUV) radiation. VUV excimer lamp irradiation was performed on one side of the membrane for 6 or 60 min. The gas permeabilities for carbon dioxide (CO2) and nitrogen (N2) were determined through a volumetric measurement method at 23 °C. The gas permeabilities for CO2 and N2 increased temporarily at 7 days after 6 and 60 min of VUV irradiation of the membranes. The change in the gas permeability for N2 was more remarkable than that for CO2. These changes were related to the C?O or SiOx ratio. The C?O ratio was related to the gas permeability of the membranes VUV‐irradiated for 6 min, whereas the SiOx ratio was related to the gas permeability of the membranes VUV‐irradiated for 60 min. These changes affected the gas selectivities of the membranes. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45973. 相似文献
13.
Jifei Jia Eishi Tanabe Peng Wang Kouichi Ito Hiroyuki Morioka Ye Wang Tetsuya Shishido Katsuomi Takehira 《Catalysis Letters》2001,76(3-4):183-192
A solid phase crystallization (spc) method was applied for the preparation of SrTiO3-supported Ni catalysts and compared to the impregnation (imp) method. spc-Ni0.2/SrTiO3 has highly dispersed and stable Ni metal particles resulting in higher activity and higher sustainability against coking than imp-Ni0.2/SrTiO3 in the partial oxidation of CH4. Both catalysts were tested for the CH4 pyrolysis in order to elucidate the catalytic nature against coking of spc-Ni0.2/SrTiO3. The amount of carbon and the rate of H2 formation were similar over both catalysts at both 773 and 1073 K. On both catalysts, CH4 continuously decomposed at 773 K, while the rate of CH4 pyrolysis quickly decreased at 1073 K. Fibrous carbons grew up with a Ni metal particle on the tip of the fiber at 773 K, while carbon balls and short carbon fibers with a Ni metal particle encapsulated inside formed and no sufficient growth of the fiber was observed at 1073 K. The carbon species formed at 773 K was hydrogenated completely to CH4 around 873 K, while the hydrogenation of that formed at 1073 K needed higher temperature around 1073 K. However, the carbon species formed on both the catalysts at either 773 or 1073 K was completely oxidized around 773 K. Thus, judging from the anti-coking nature, the behaviors in the CH4 pyrolysis are similar over both catalysts, nonetheless spc-Ni0.2/SrTiO3 was far superior to imp-Ni0.2/SrTiO3 in the CH4 oxidation. It is likely that the high sustainability against coking of spc-Ni0.2/SrTiO3 is not due to its intrinsic nature suppressing the coking but due to its high activity of reforming which can quickly eliminate the carbon formed on the catalyst surface. 相似文献
14.
Satoru Iwamori Takehiro Miyashita Shin Fukuda Shouhei Nozaki Nobuhiro Fukuda Kazufuyu Sudoh 《The Journal of Adhesion》1997,63(4):309-321
Peel strength between a copper (Cu) thin film and a polyimide (pyromellitic dianhydride-oxydianiline, or PMDA-ODA) substrate is reduced by heat treatment at 150°C in air. In this work, we investigated the peel strength, the morphology of the interface between Cu films and polyimide substrates using optical microscopy and electron microscopy, and chemical change of the interface using Auger electron spectroscopy (AES) and micro X-ray photoelectron spectroscopy (XPS). The analysis showed that CuO “lumps” were present on the peeled surface of PMDA-ODA after heat treatment at 150°C in air. The peeled surfaces of other polyimide substrates were also analyzed: biphenyl dianhydride-para phenylene diamine (BPDA-PDA) and biphenyl dianhydride-oxydianiline (BPDA-ODA). CuO lumps were present on the peeled surface of BPDA-ODA after the heat treatment, but not that of BPDA-PDA. Compared with the adhesion strength for the Cu thin film, the adhesion strength was high for the Cu/PMDA-ODA and Cu/BPDA-ODA laminates, but the adhesion strength was very low for the Cu/BPDA-PDA laminate. This low strength is the reason that CuO lumps were not detected on the peeled surface of the BPDA-PDA substrate. These CuO lumps were related to the adhesion degradation of the Cu/polyimide laminates after the heat treatment. 相似文献
15.
16.
K Sekihara S S Nagarajan D Poeppel A Marantz Y Miyashita 《IEEE transactions on bio-medical engineering》2001,48(7):760-771
We have developed a method suitable for reconstructing spatio-temporal activities of neural sources by using magnetoencephalogram (MEG) data. The method extends the adaptive beamformer technique originally proposed by Borgiotti and Kaplan to incorporate the vector beamformer formulation in which a set of three weight vectors are used to detect the source activity in three orthogonal directions. The weight vectors of the vector-extended version of the Borgiotti-Kaplan beamformer are then projected onto the signal subspace of the measurement covariance matrix to obtain the final form of the proposed beamformer's weight vectors. Our numerical experiments show that both spatial resolution and output signal-to-noise ratio of the proposed beamformer are significantly higher than those of the minimum-variance-based vector beamformer used in previous investigations. We also applied the proposed beamformer to two sets of auditory-evoked MEG data, and the results clearly demonstrated the method's capability of reconstructing spatio-temporal activities of neural sources. 相似文献
17.
Yu Miyashita Sang-Hyuck Park Hoon Hyung Ching-Hua Huang Jae-Hong Kim 《Canadian Metallurgical Quarterly》2009,135(9):788-795
Rejection of selected N-nitrosamines, a group of probable human carcinogens, and their precursors by nanofiltration (NF) and brackish water reverse osmosis (BWRO) membranes was evaluated using a bench-scale cross-flow filtration apparatus. The tested nitrosamines included N-nitrosodimethylamine, N-nitrosomethylethylamine, N-nitrosopyrrolidine, N-nitrosodiethylamine, N-nitrosodi-n-propylamine, and N-nitrosodi-n-butylamine. The target nitrosamine precursors included secondary amines such as dimethylamine, methylethylamine, diethylamine, and dipropylamine. Rejection of nitrosamines varied greatly depending on the tested membranes (9–75% for NF membranes and 54–97% for BWRO membranes) and the molecular weight of nitrosamines. Experimental data obtained with the BWRO membranes matched well with an irreversible thermodynamic model coupled with film theory. The model further suggested that effective diffusion of nitrosamines through the BWRO membranes is responsible for the relatively low rejections observed experimentally, and the aqueous diffusivity of nitrosamines could be used as an accurate measure of nitrosamine permeability through these membranes. The steady-state rejection of all the tested nitrosamine precursors reached over 98%. This study suggests that a strategy for membrane-based water treatment processes to reduce nitrosamines should consider the removal of precursors before nitrosamines are formed during subsequent disinfection and water distribution. 相似文献
18.
T. Watanabe H. Kashiwagi S. Miyashita N. Ichioka K. Tokiwa A. Iyo Y. Tanaka S.K. Agarwal H. Ihara 《Journal of Low Temperature Physics》1999,117(3-4):753-757
We have synthesized the single phase samples of Cu
x
C
0.1
Ba
2
Ca
3
Cu
4
O
z
(x=0.20.9). Transport and magnetic measurements and iodometric titration analysis were carried out for these materials. From these results we discuss the correlation between T
c
, the Hall number, copper valence and oxygen content. The effect of the substituted M ions on T
c
in (CuC, M)-l234 (M=Ni,Zn,Al,TI,Mg) is also discussed. We propose a unique selective carrier-doping mechanism in (Cu,C)- and (CuC,Mg)-1234 systems. 相似文献
19.
Low-loss single-mode fibres with GeO2-doped SiO2 cores have been made by the c.v.d. method and the loss spectrum from 0.6 to 1.8 ?m measured. The minimum loss of the fibre with suitably designed parameters, characterised by the refractive-index difference and the core diameter, was 0.75 dB/km at 1.05 ?m. 相似文献
20.
Katsuyama Yutaka Ishida Yukinori Ishihara Koushi Miyashita Tadashi Tsuchiya Haruhiko 《Electronics letters》1979,15(3):94-95
A new method for determining suitable single-mode fibre parameters is examined. Suitable fibre parameters are determinable by minimising cabling- and splicing-loss increases. An eight-fibre cable was manufactured and the loss increases were measured. ? = 0.2% and V = 2.2 are the values selected using this method and for the experimental results. 相似文献