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41.
Toyoda M Ishihara M Yamaguchi S Ito H Matsuo T Roll R Rosenbauer H 《Journal of mass spectrometry : JMS》2000,35(2):163-167
A new type of multi-turn time-of-flight mass spectrometer was constructed, consisting of four cylindrical electric sectors and 28 electric quadrupole lenses, the size of the vacuum chamber being 60 x 70 x 20 cm. It was demonstrated that the mass resolution can be increased according to the number of cycles of the ions through the ion optical system. 相似文献
42.
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44.
Masafumi Unno Hiroyuki Murakami Satoshi Kagawa Hideyuki Matsumoto 《Silicon Chemistry》2007,3(3-4):195-198
Two new silanols bearing very bulky silyl groups, (i-Pr3
Si)3SiOH and (t − BuMe2Si)3SiOH were prepared by peracidoxidation of their respective silanes. The X − ray crystallographic analysis revealed that (t − BuMe2Si)3 SiOH forms a dimeric structure with hydrogen bonding, while (i − Pr3 Si)3 SiOH exists as a monomer in the crystal. The effects of the size of the substituents as well as the reactivity of these silanols
are discussed. 相似文献
45.
Ohwada T Miura M Tanaka H Sakamoto S Yamaguchi K Ikeda H Inagaki S 《Journal of the American Chemical Society》2001,123(42):10164-10172
N-Nitrosamines can be considered as potential nitric oxide (NO)/nitrosonium ion (NO(+)) donors. However, the relation of the structures of N-nitrosamines, in particular of aliphatic N-nitrosamines, to the characteristics of release of NO or NO(+) remains unclear. Here we show that aliphatic N-nitrosoamines of 7-azabicyclo[2.2.1]heptanes can undergo heterolytic N-NO bond cleavage. On the basis of the observation of reduced rotational barriers of the N-NO bonds in solution and nitrogen-pyramidal structures of the N-nitroso group in the solid state, we postulate that N-NO bond cleavage of N-nitrosamines is enhanced by a reduction of the resonance in the N-NO group. Computational studies suggest that these structural features of the N-nitrosamines of 7-azabicyclo[2.2.1]heptane are derived from angle strain imposed on the CNC angles. 相似文献
46.
Takayuki Abe Shingo Higashide Mitsuhiro Inoue Satoshi Akamaru 《Plasma Chemistry and Plasma Processing》2007,27(6):799-811
Fine particles were modified with a thin film of SnO2 by using a barrel sputtering system that is a dry process. The conditions for the preparation of SnO2 were studied by reactive sputtering onto a glass plate substrate. The optimal conditions for the preparation of tetragonal
SnO2 were identified as 60% partial oxygen pressure and 1.0 Pa total gas pressure with the substrate at room temperature. Under
the optimized conditions, the surfaces of Al flake particles were modified with a thin film of SnO2. XRD and SEM/EDS analysis of the prepared samples showed that the Al particle surfaces were uniformly modified by a thin
film of SnO2 in all cases. The film thicknesses were 80, 130, and 180 nm at RF outputs of 195, 350, and 490 W. These measured thicknesses
coincided with the values estimated from the interference colors of the samples. 相似文献
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49.
Yoshihiro Itoh Masamitsu Inoue Tomoko Takahashi Akira Hachimori Satoshi Suzuki 《Journal of polymer science. Part A, Polymer chemistry》1995,33(7):1069-1074
Alternating and random copolymers of 9-phenanthrylmethyl methacrylate or 2-(9-carbazolyl)ethyl methacrylate with styrene were synthesized and their fluorescence properties were examined. There was no noticeable difference in the spectral features of the alternating and random copolymers in tetrahydrofuran (THF), demonstrating that this type of polymers have no quenching sites in the polymer chains. The fluorescence quenching studies indicated that the alternating copolymers permitted singlet-state energy migration as efficiently as the corresponding random copolymers but less efficiently than the random copolymers with higher chromophore contents. These results strongly suggest that to be chromophores close to each other is most important for facilitation of an intramolecular energy migration. © 1995 John Wiley & Sons, Inc. 相似文献
50.
Abe K Ahrens LA Amako K Aronson SH Beier EW Callas JL Cutts D Diwan M Durkin LS Gibbard BG Heagy SM Hedin D Hoftun JS Hurley M Kabe S Kurihara Y Lanou RE Mann AK Marx MD Murtagh MJ Nagashima Y Newcomer FM Shinkawa T Stern E Suzuki Y Terada S White DH Williams HH Yamaguchi Y 《Physical review letters》1987,58(7):636-639