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111.
Hisakazu Kotani Masayoshi Yamada Keiichi Yamamoto Kenji Abe 《Solid State Communications》1982,41(6):461-463
Time-resolved optical transmission of annealing dye laser pulse (wavelength : 590 nm and pulse width : 250 nsec) itself has been measured in thin layers of Si+-implanted amorphized silicon-on-sapphire (SOS) with several energy densities in the range of 0.02 to 2.64 J/cm2. At the energy densities where the amorphized SOS is recrystallized, the transmission exhibits a sudden drop and subsequently remains at a detectable level. This laser-induced absorption is inconsistent with the presence of ordinary molten silicon but suggests an electronic structural-change from amorphous to crystalline state. 相似文献
112.
113.
114.
Kumio Okaichi Nobuyuki Kajitani Katuko Nakajima Keiichi Nozu † Takeo Ohnishi † 《Photochemistry and photobiology》1989,50(1):69-73
Irradiation by health lamp (HL) light (280–320 nm) more efficiently induced cell killing and mutation in a radiation sensitive mutant (TW8) of Dictyostelium discoideum as compared with the parental wild-type strain (NC4). This light as well as a germicidal lamp-light (254 nm) produced pyrimidine dimers. The dimers were removed from DNA molecules by excision repair in NC4, but more slowly in TW8. It is suggested that pyrimidine dimers are the main DNA damage caused by HL light in D. discoideum , and that this results in cell killing and induced mutation. 相似文献
115.
116.
4-Diazomethyl-substituted coumarins, 1-methyl-2(1H)-quinolinones, 1 -thiocoumarin and their tricyclic analogs were found to be easily cyclized into the corresponding pyrazole isomers condensed with heteroaromatics. Thermodependent feature of these conversions and the remarkably accelerating effect of the alkyl substituent peri to the diazomethyl group were realized. Some other diazomethyl compounds connected with 2-pyridinone, 3-pyrazolone, chromone and 1-thiochromone were prepared, and their stability and thermal properties were compared. 相似文献
117.
118.
Hirotada Fujiwara Tadashi Narita Hiroshi Hamana 《Journal of polymer science. Part A, Polymer chemistry》2003,41(18):2743-2754
The results on radical self‐polyaddition reactivity of two trialkylsilyl perfluoroisopropenyl ethers, triethysilyl perfluoroisopropenyl ether [CF2?C(CF3)OSi(C2H5)3] (FTEE) and dimethylphenylsilyl perfluoroisopropenyl ether [CF2?C(CF3)OSi(CH3)2C6H5] (DMPE), and two perfluoroisopropenyl carboxylates, 2‐butyroxypentafluoropropene [CF2?C(CF3)OCOC3H7] (BuFPP) and 2‐(methoxyacetoxy)pentafluoropropene [CF2?C(CF3)OCOCH2OCH3] (MFPP), are described. Radical self‐polyaddition of FTEE afforded a polymer as high as 1.87 × 104 in molecular weight in the presence of radical generators such as benzoyl peroxide and di‐tert‐butyl peroxide. DMPE gave only addition products with initiating radicals. BuFPP and MFPP scarcely yielded even addition products with radical. The mechanism that the self‐polyaddition of FTEE was initiated by the addition of radical onto the perfluoroisopropenyl group followed by a 1,5‐shift to afford a methyl radical that attacked the perfluoroisopropenyl group of another FTEE molecule is proposed. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 2743–2754, 2003 相似文献
119.
M. Taniguchi S. Suga M. Seki H. Sakamoto H. Kanzaki Y. Akahama S. Endo S. Terada S. Narita 《Solid State Communications》1984,49(9):867-870
Valence band photoemission spectra of black phosphorus have shown anomalous behavior at the excitation of 2p core-excitons. The intensity of the 2.7 ev peak shows a clear Fano type interference due to a direct recombination of core-excitons leaving one hole in valence bands. Besides, strong enhancement of the 10.8 eV peak is interpreted as due to a core-exciton induced resonance with two-hole final states. The role of core-excitons as intermediate states for photoemission processes is newly revealed in the experiments. 相似文献
120.
A new variant of phosphoric acid-catalyzed C-C bond forming reaction, direct alkylation of alpha-diazoester, via C-H bond cleavage is presented. The resulting products, beta-amino-alpha-diazoesters, are highly functionalized and useful synthetic precursors for various types of beta-amino acids. 相似文献