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51.
Kazuhiro Kanda Noriko Yamada Kumiko Yokota Masahito Tagawa Masahito Niibe Makoto Okada Yuichi Haruyama Shinji Matsui 《Diamond and Related Materials》2011,20(5-6):703-706
Surface modification of diamond-like carbon (DLC) film was performed using a hyperthermal atomic fluorine beam on the purpose of production of hydrophobic surface by maintaining the high hardness of DLC film. By the irradiation of atomic fluorine beam of a 1.0 × 1020 atoms/cm2, the contact angle of a water drop against the DLC surface increased from 73° to 111°. The formation of CF3, CF2 and CF bonding on the modified DLC surface was confirmed from the measurements of X-ray photoelectron spectra and near-edge X-ray absorption fine structure spectra. Irradiation of hyperthermal atomic fluorine beam was concluded to produce insulator fluorine-terminated DLC film, which has high F content on the surface, by the taking of the use of neutral atomic beam as a fluorine source. 相似文献
52.
53.
Selectivity and mechanism for skeletal isomerization of alkanes over typical solid acids and their Pt-promoted catalysts 总被引:2,自引:0,他引:2
Atsuyuki Miyaji Tsuneo Echizen Lianshun Li Tetsuo Suzuki Yusuke Yoshinaga Toshio Okuhara 《Catalysis Today》2002,74(3-4):291-297
Selectivities for skeletal isomerizations of n-butane and n-pentane catalyzed by typical solid acids such as Cs2.5H0.5PW12O40 (Cs2.5), SO42−/ZrO2, WO3/ZrO2, and H-ZSM-5 and their Pt-promoted catalysts were compared. High selectivities for n-butane and low selectivity for n-pentane were observed over Cs2.5 and SO42−/ZrO2, while H-ZSM-5 was much less selective, and WO3/ZrO2 was highly selective for both reactions. The Pt-promoted solid acids were usually selective for these reactions in the presence of H2 except for Pt-H-ZSM-5 for n-butane isomerization. Both the acid strength and pore structure would be factors influencing the selectivity. Mechanism of skeletal isomerization of n-butane was investigated by using 1,4-13C2-n-butane over Cs2.5 and Pt–Cs2.5. It was concluded that n-butane isomerization proceeded mainly via monomolecular pathway with intramolecular rearrangement on Pt–Cs2.5, while it occurred through bimolecular pathway with intermolecular rearrangement on Cs2.5. The higher selectivity on Pt–Cs2.5 would be brought about by the monomolecular mechanism. In the skeletal isomerization of cyclohexane, Pt–Cs2.5/SiO2 was highly active and selective, while Pt–Cs2.5 was less selective. Control in the acid strength of Cs2.5 by the supporting would be responsible for the high selectivity. 相似文献
54.
The primary and secondary particle sizes of monoclinic hydrous-ZrO2 particles produced by the hydrolysis of various ZrOCl2 solutions, with and without the addition of NaCl, CaCl2 , or AlCl3 , were measured using X-ray diffraction and transmission electron microscopy in order to clarify the formation mechanisms of primary and secondary particles. The primary particle size of hydrous ZrO2 , under a constant ZrOCl2 concentration, decreased monotonously with increasing Cl− -ion concentration. On the contrary, the secondary particle size increased monotonously with increasing Cl− -ion concentration. The present experimental results revealed that the primary and secondary particle sizes of hydrous ZrO2 are controlled primarily by the concentrations of H+ and Cl− ions produced during hydrolysis, and are independent of the type of added metal ions. The formation mechanisms of the primary and secondary particles of hydrous ZrO2 were determined on the basis of the present experimental results. 相似文献
55.
Mitsunobu Kawano Toshiaki Matsui Ryuji Kikuchi Hiroyuki Yoshida Toru Inagaki Koichi Eguchi 《Journal of power sources》2008
Direct internal and external reforming operations on Ni-samaria-doped ceria (SDC) anode with the practical size solid oxide fuel cell (SOFC) at intermediate temperatures from 600 to 750 °C are carried out to reveal the reforming activities and the electrochemical activities, being compared with the hydrogen-fueled power generation. The cell performance with direct internal and external steam reforming of methane and their limiting current densities were almost the same irrespective of the progress of reaction in the methane reformate at 700 and 750 °C. The durability test for 5.5 h at 750 °C with direct internal reforming operation confirmed that the cell performance did not deteriorate. The operation temperature of the cell controlled the reforming activities on the anode, and the large size electrode gave rise to high conversion due to the slow space velocity of the steam reforming. Direct internal steam reforming attained sufficient level of conversion for SOFC power generation with methane at 700 and 750 °C on the large Ni-SDC cermet anode. 相似文献
56.
The diffusion coefficient (D) values of tert‐butyloxycarbonyl‐glycine, tert‐butyloxycarbonyl‐L ‐tryptophan, tert‐butyloxycarbonyl‐L ‐phenylalanine (Boc‐Phe), and 9‐fluorenylmethoxycarbonyl‐L ‐phenylalanine in Merrifield polystyrene (MPS) gels, poly(ethylene glycol)‐grafted polystyrene (PEG–PS) gels, and crosslinked ethoxylate acrylate (CLEAR) gels, as used in solid‐phase peptide synthesis, were determined by the pulsed‐field‐gradient spin‐echo 1H‐NMR method. From these experimental results, it was found that the amino acids in MPS gels, PEG–PS gels, and CLEAR gels with N,N‐dimethylformamide‐d7 (DMF‐d7) as a solvent had multidiffusion components within a measurement timescale of 10 ms. The D value of Boc‐Phe in polystyrene gels (1% divinylbenzene crosslinked) with tetrahydrofuran‐d8 was much larger than that in the same gels with DMF‐d7. Furthermore, the required time in which an amino acid transferred from a reactive site to a reactive site was estimated, within which the solvents and amino acids in the polymer supports diffused in the swollen beads.© 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 413–421, 2003 相似文献
57.
Kotaro Hama Yuko Fujiwara Masashi Morita Fumiyoshi Yamazaki Yuko Nakashima Shiro Takei Shigeo Takashima Mitsutoshi Setou Nobuyuki Shimozawa Tsuneo Imanaka Kazuaki Yokoyama 《Lipids》2018,53(1):85-102
ABCD1 is a gene responsible for X‐linked adrenoleukodystrophy (X‐ALD), and is critical for the transport of very long‐chain fatty acids (VLCFA) into peroxisomes and subsequent β‐oxidation. VLCFA‐containing lipids accumulate in X‐ALD patients, although the effect of ABCD1‐deficiency on each lipid species in the central nervous system has not been fully characterized. In this study, each phospholipid and lysophospholipid species in Abcd1‐deficient mice brains were profiled by liquid chromatography‐mass spectrometry. Among the phospholipid and lysophospholipid species that are significantly more enriched in Abcd1‐deficient mice brains, VLCFA were present in 75, 15, 5, 4, and 1 species of phosphatidylcholine, phosphatidylethanolamine, sphingomyelin, lysophosphatidylcholine, and lysophosphatidylethanolamine, respectively. Most VLCFA were incorporated at the sn‐1 position of phosphatidylcholine and phosphatidylethanolamine. Among the phospholipid species that are significantly less enriched in Abcd1‐deficient mice brains, odd‐numbered saturated or mono‐unsaturated fatty acyl moieties are contained in all phosphatidylcholine species. In addition, a number of phosphatidylglycerol, phosphatidylinositol, and phosphatidylserine species contained highly unsaturated fatty acyl moieties. Intriguingly, 44:1 phosphatidylcholine with VLCFA was mainly distributed in the gray matter, such as the cortex, but not in the white matter in the cerebrum and cerebellum. These results show that ABCD1‐deficiency causes metabolic alternation of long‐chain fatty acids and VLCFA. Moreover, our results imply a molecular mechanism for the incorporation of saturated or monounsaturated VLCFA into the sn‐1 position of phospholipids, and also indicate that the distribution of phospholipids with VLCFA may correlate with the development of X‐ALD. 相似文献
58.
Koji Matsui Nobukatsu Ohmichi Michiharu Ohgai Naoya Enomoto Junichi Hojo 《Journal of the American Ceramic Society》2005,88(12):3346-3352
The sinterabilities of fine zirconia powders including 5 mass% Y2 O3 were investigated, with emphasis on the effect of Al2 O3 at the initial sintering stage. The shrinkage of powder compact was measured under constant rates of heating (CRH). The powder compact including a small amount of Al2 O3 increased the densification rate with elevating temperature. The activation energies at the initial stage of sintering were determined by analyzing the densification curves. The activation energy of powder compact including Al2 O3 was lower than that of a powder compact without Al2 O3 . The diffusion mechanisms at the initial sintering stage were determined using the new analytical equation applied for CRH techniques. This analysis exhibited that Al2 O3 included in a powder compact changed the diffusion mechanism from grain boundary to volume diffusions (VD). Therefore, it is concluded that the effect of Al2 O3 enhanced the densification rate because of decrease in the activation energy of VD at the initial sintering stage. 相似文献
59.
N. Koizumi T. Hemmi K. Matsui H. Nakajima K. Okuno K. Kuno K. Nomoto 《Fusion Engineering and Design》2009,84(2-6):210-214
Research and trials by the Japan Atomic Energy Agency (JAEA) focus on the remaining technical issues in the ITER TF coil winding pack (WP) manufacturing process. Specific issues include the feasibility of automatically measuring conductor length during automatic winding with a high degree of accuracy (±0.02%) and a fabrication process to comply with the demanding tolerances (up to 1 mm distortion in flatness and 1.5 mm in-plane shrinkage) of the radial plate (RP) due to cover plate (CP) welding. The authors developed a new technique to measure conductor length very accurately by combining an ordinary encoder and a newly developed optical system. A simulation based on test results of CP welding using a RP mock-up indicates that a flatness of 1 mm is achievable, but the in-plane shrinkage of the RP is approximately 5 mm. One possible solution is to fabricate the RP larger than required to allow for in-plane shrinkage. Another solution is to reduce the thickness or length of the welding. The feasibility of these solutions to most of the major technical issues suggests that it is time for full qualification testing of the fabrication process in a dummy double-pancake trial. 相似文献
60.
A novel substrate {Galβ1,4GlcNAcβ1,4GlcNAc-β-pNP [Gal(GlcNAc)2-β-pNP]} for assaying lysozyme activity has been designed using docking simulations and enzymatic synthesis via β-1,4-galactosyltransferase-mediated transglycosylation from UDP-Gal as the donor to (GlcNAc)2-β-pNP as the acceptor. Hydrolysis of the synthesized Gal(GlcNAc)2-β-pNP and related compounds using hen egg-white lysozyme (HEWL) demonstrated that the substrate was specifically cleaved to Gal(GlcNAc)2 and p-nitrophenol (pNP). A combination of kinetic studies and docking simulation was further conducted to elucidate the mode of substrate binding. The results demonstrate that Gal(GlcNAc)2-β-pNP selectively binds to a subsite of lysozyme to liberate the Gal(GlcNAc)2 and pNP products. The work therefore describes a new colorimetric method for quantifying lysozyme on the basis of the determination of pNP liberated from the substrate. 相似文献