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991.
Tsubasa Matsumoto Hiromitsu Kato Norio Tokuda Toshiharu Makino Masahiko Ogura Daisuke Takeuchi Hideyo Okushi Satoshi Yamasaki 《固体物理学:研究快报》2014,8(2):137-140
The contact resistance between heavily phosphorus doped n‐type (n+‐type) diamond (111) layers and graphite electrodes was investigated. To analyze the contact resistance properties in detail in the low‐voltage region, the transfer length method including nonlinear terms with a constant current was analyzed based on the double Schottky contact configuration. Using this method, we have revaluated the metal contact resistance reported previously. Using the graphite electrodes, the linearity of current‐voltage characteristics was improved. The contact resistance was reduced by a factor of ten compared to that of conventional Ti/Pt/Au electrodes. The graphite electrodes were formed directly by thermal annealing at 1300 °C for 10 min from an n+‐type diamond surface. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
992.
Seizo Tamagaki Masahiko Takahashi Junji Kanamori Waichiro Tagaki 《Supramolecular chemistry》2013,25(2):159-164
Abstract Equilibria involved in the Schiff base formations of pyridoxal 5′-phosphate (PLP) and 5′-deoxypyridoxal with mono-, di-, and peraminocyclodextrins have been studied to determine equilibrium binding constants in aqueous media at several pH values. These results, as well as the circular dichroism study, show that remote electrostatic interactions between the negatively charged 5′-phosphate group and a second ammonium group on the cyclodextrins play a significant role in the complexation. 相似文献
993.
Jin Motoyanagi Kiriko Higashi Masahiko Minoda 《Journal of polymer science. Part A, Polymer chemistry》2014,52(19):2800-2805
We have newly designed an original bifunctional monomer (PAVE) containing both a phenylacetylene (PA) group and a vinyl ether (VE) group, which is expected to be a key material for the synthesis of brush‐shaped polymers consisting of a poly(phenylacetylene) (polyPA) main chain and polyVE side chains. Actually, we have demonstrated the selective chemical transformation of the VE moiety of PAVE to an initiator site for the living cationic polymerization of isobutyl vinyl ether (IBVE), and then succeeded in the controlled synthesis of a novel PA‐end‐capped polyIBVE macromonomer. Moreover, using this macromonomer, the first synthesis of a brush‐shaped polyPA bearing polyVE side chains was achieved via Rh complex‐mediated homopolymerization. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 2800–2805 相似文献
994.
Bungo Ochiai Yuuko Ootani Tetsushi Maruyama Takeshi Endo 《Journal of polymer science. Part A, Polymer chemistry》2007,45(24):5781-5789
Polymethacrylates carrying cyclic carbonate through urethane linkage were prepared by radical (co)polymerizations of 2‐methacrylic acid 2‐(2‐oxo‐[1,3]dioxolan‐4‐ylmethoxycarbonylamino)ethyl ester (CUMA). Although brittleness of typical polymers bearing cyclic carbonate groups has been limited their practical applications, some copolymers from CUMA can be cast as films with good flexibility. The copolymers from CUMA and diethyleneglycol methyl ether methacrylate are miscible with lithium bis(trifluoromethanesulfone)imide. The coordination of the lithium cation to the carbonyl groups was confirmed by infrared spectrometry. © 2007 Wiley Periodicals, Inc. JPolym Sci Part A: Polym Chem 45: 5781–5789, 2007 相似文献
995.
We confirmed that concentrations of polycyclic aromatic hydrocarbons (PAHs) obtained by isotope dilution mass spectrometry (IDMS) using the corresponding (13)C-labeled internal standards are reliable even after clean-up steps. Change in the ratio of phenanthrene to (13)C(6)-phenanthrene was less than 0.2%, although the recovery yield of (13)C(6)-phenanthrene decreased to 60%. Since changes in the ratios were commonly within the relative standard deviations of the concentrations (1.5 - 5.4%) obtained using gas chromatography-mass spectrometry in combination with pressurized-liquid extraction, concentrations obtained by IDMS with (13)C-PAHs should be reliable. 相似文献
996.
Masahiko Takahashi Shigeru Muta Hiroshi Nakazato 《Journal of heterocyclic chemistry》1997,34(5):1395-1398
1-Alkyl-3-trifluoromethylpyrazole-4-sulfonamides 10 , (2-trifluoromethyl-2,3-dihydrobenzimidazol-2-yl)methanesulfonamides 12 , and (2-benzimidazolyl)metbanesulfonamides 13 were prepared starting from 3,3,3-trifluoro-2,2-dihydroxypropanesulfonamides 1 . 相似文献
997.
Daisuke Nagai Masato Sato Bungo Ochiai Takeshi Endo 《Journal of polymer science. Part A, Polymer chemistry》2006,44(16):4795-4803
The cationic ring‐opening polymerization of a five‐membered thiourethane [3‐benzyl‐1,3‐oxazolidine‐2‐thione (BOT)] with boron trifluoride etherate afforded the corresponding polythiourethane with a narrow molecular weight distribution in an excellent yield. The molecular weight of the polymers could be controlled by the feed ratio of the monomer to the initiator. A kinetic study of the polymerization revealed that the polymerization rate of BOT (1.3 × 10?2 L mol?1 min?1) was two times larger than that of the six‐membered thiourethane [3‐benzyltetrahydro‐1,3‐oxazolidine‐2‐thione (BTOT); 6.8 × 10?3 L mol?1 min?1], and the monomer conversion obeyed the first‐order kinetic equation. These observations, along with the successful results in the two‐stage polymerization, supported the idea that this polymerization proceeded in a controlled manner. Block copolymerizations of BOT with BTOT were also carried out to afford the corresponding di‐ and triblock copolymers with narrow molecular weight distributions. The order of the 5% weight loss temperatures was as follows: poly(3‐benzyltetrahydro‐1,3‐oxazolidine‐2‐thione) [poly(BTOT)] > poly(BTOT54‐b‐BOT46) > poly(3‐benzyl‐1,3‐oxazolidine‐2‐thione) [poly(BOT)]. This indicated that an increase in the BTOT unit content raised the decomposition temperature. The order of the refractive indices was poly(BOT) > poly(BTOT54‐b‐BOT46) > poly(BTOT54‐b‐BOT46‐b‐BTOT50) > poly(BTOT); this was in accord with the order of the sulfur content in the polymer chain. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 4795–4803, 2006 相似文献
998.
S. Takagi T. Suzuki A. Amato F.N. Gygax A. Schenck A. Ochiai 《Hyperfine Interactions》1997,106(1-4):151-156
The spin relaxation of Mu was measured in mixtures of CO and Ar at pressures up to 270 atm and at various magnetic fields.
The relaxation rate increased with magnetic field in the way expected for electron spin‐exchange processes, though the effect
declined at high pressures. We describe the results in terms of spin relaxation of Mu‐formyl radicals, MuCO, which break up
to give depolarized Mu at low pressures, but are increasingly stabilized at higher pressures.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
999.
Mitsunobu Doi Terue Nakamori Makio Shibano Masahiko Taniguchi Nian‐He Wang Kimiye Baba 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(11):o833-o835
Candibirin A [systematic name: 9,9′‐(1,4‐dioxane‐2,5‐diyldimethylenedioxy)di(7H‐furo[3,2‐g]chromen‐7‐one)], a new furanocoumarin dimer, was isolated from Heracleum candicans Wall . 1H NMR and MS spectra had indicated that the title compound was a dimer of heraclenin or heraclenol, but the linkage structure and its chirality were undetermined. The dioxane linkage, having the R,R configuration, has now been elucidated from dimethyl sulfoxide‐solvated crystals, C32H28O10·2C2H6OS. Candibirin A is thus a dimerization product from heraclenin formed by reaction at the epoxy group. Dimethylformamide‐solvated crystals, C32H28O10·C3H7NO, adopt a different conformation, with a folded structure that differs from the extended structure in the dimethyl sulfoxide solvate. However, the puckering of the dioxane linker unit is very similar in the two conformers. This result shows that the rotation of the ether bonds, in the linker between the furanocoumarin and dioxane moieties, causes the conformational flexibility of (I). 相似文献
1000.
T. Sasaki K. Miyamoto N. Oguri K. Ishibashi N. Aoki Y. Ochiai 《Superlattices and Microstructures》2003,34(3-6):371
We have investigated the damage in multi-wall carbon nanotubes (MWNTs) destroyed by electrical breakdown and focused ion beam bombardment (FIBB). The transport properties of a MWNT destroyed by electrical breakdown have been compared with those of a MWNT destroyed by FIBB. Also the Tomonaga–Luttinger transport (TLT) model has been applied to each type of destroyed MWNT. The MWNT destroyed by FIBB showed TLT behavior because of the weak destruction of the remaining walls. However, in the case of MWNTs destroyed by electrical breakdown, three-dimensional variable-range hopping (VRH) was observed in the low temperature transport. This suggests that the local damage has been caused by strong breakdown. There exists a clear difference between the effects of electrical breakdown and FIBB. Wall destruction by FIBB could be applied to control the one-dimensional transport of MWNTs. 相似文献