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41.
In systematic research on a series of new nonlinear organic materials, we found that Bis (4-nitrophenoxy) methane (BNPM) showed a large intensity of second harmonic light, which was 4.4 times as large as that of urea crystal by powder technique and easily crystallized from a solution. The crystal structure of BNPM, obtained by the X-ray diffraction method, was orthorhombic, space group P21212 (point group 222), with unit-sell dimension a = 10.205 Å; b = 12.854 Å; c = 4.8822 Å. In addition, we found that the absorption edge of BNPM was 430 nm with a 0.9-mm-thick crystal, and we observed the second harmonic light with BNPM single crystal at the wavelength of 1064 nm and in the range from 906 nm to 990 nm. 相似文献
42.
Kazuhiko Mase Mitsuru Nagasono Shin-ichiro Tanaka Tsuneo Urisu Eiji Ikenaga Tetsuji Sekitani Ken-ichiro Tanaka 《Surface science》1997,390(1-3):97-101
Ion desorption induced by a resonant excitation of O 1s of condensed amorphous H2O has been studied by total ion and total electron yield spectroscopy, nonderivative Auger electron spectroscopy (AES) and Auger electron photo-ion coincidence (AEPICO) spectroscopy. The spectrum of total ion yield divided by total electron yield exhibits a characteristic threshold peak at hν = 533.4 eV, which is assigned to the 4a1 ← O 1s resonant transition. The AES at the 4a1 ← O 1s resonance is interpreted as being composed of the spectator-AES of the surface H2O, and the normal-AES of the bulk H2O, where the 4a1 electron is delocalized before Auger transitions. H+ is found to be the only ion species in AEPICO spectra measured at the 4a1 ← O 1s resonance and at the O 1s ionization (hν = 560 eV). The electron kinetic energy dependence of the AEPICO yield (AEPICO yield spectrum) at the 4a1 ← O 1s resonance is found to be greatly different from that at the O 1s ionization. The peak positions of the AEPICO yield spectrum at the 4a1 ← O 1s resonance are found to correspond to those of the spectator-AES of the surface H2O, which is extracted from the AES at the 4a1 ← O 1s resonance. Furthermore, the AEPICO yield is greatly enhanced at the 4a1 ← O 1s resonance as compared with that at the O 1s ionization. On the basis of these results, a spectator-Auger-stimulated ion desorption mechanism and/or ultra-fast ion desorption mechanism are concluded to be responsible for the H+ desorption at the 4a1 ← O 1s resonance. The enhancement of the H+ yield is ascribed to the O---H anti-bonding character of the 4a1 orbital. 相似文献
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Tetsuji Kametani Keiichiro Fukumoto Fumio Satoh Kazuo Kigasawa Hideo Sugi 《Journal of heterocyclic chemistry》1976,13(1):29-31
Hydrogenation of the homoproaporphine (IV) over platinum oxide gave a mixture of the cyclohexanols VIIa and VIIb. In contrast, reduction of IV on palladium provided the cyclo-hexanone VI, which was also obtained from VIIb by oxidation. Treatment of the cyclohexanols VIIa and VIIb under hydrogen on platinum oxide afforded the same mixture of VIIa and VIIb. 相似文献
46.
A new type of 5-deazaflavin derivative with axial and planar chirality was synthesized as a flavoenzyme model. A novel optical resolution gave an enantiomeric pair of the 5-deazaflavins 1a,b. Compounds1a,b were optically stable and effectively discriminated PNPH enantiomers in a model reaction of intercoenzyme hydrogen transfer. 相似文献
47.
Tetsuji Kawabe Yasuaki Ohtani Kisei Kinoshita 《Zeitschrift fur Physik C Particles and Fields》1980,3(4):299-305
We present a gluon jet model for the heavy quarkonium decay incorporating the color neutralization mechanism. Postulating that final hadrons are produced from the color singlet quark-antiquark pair originated each from different gluons, we formulate the production mechanism of hadrons from gluons explicitly. The fragmentation function thus obtained can describe the hadron production not only in the fragmentation region but also in the central one owing to the usage of the Sudakov variables. The result of the average charged multiplicity from Υ(9.46) is in reasonable agreement with the data, in contrast to the naive estimates. Furthermore, the inclusive momentum and multiplicity distributions are discussed. 相似文献
48.
Tetsuji Kawabe 《Zeitschrift fur Physik C Particles and Fields》1983,16(4):367-371
Under the assumption that a scalar diquark coexists in part of the time with a single quark within a nucleon, which is favored to describe the higher twist effects of both γ and ν induced nucleon structure functions consistently, we consider how its presence affects nucleon properties. It is shown that the sum rule and the magnetic moment constrain its contribution strongly and the asymmetry is quite sensitive to it. In particular, theR=σ L /σ T ratio can be explained in terms of the large transverse momentum of the diquark which arises from the consideration on the neutron charge radius value. 相似文献
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