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121.
122.
The results of the measurement of Raman scattering spectra and infra-red absorption spectra of densified vitreous silica are reported. Raman active-low frequency vibrations are largely changed by compression. 相似文献
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124.
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
125.
Keiichi Kimura Hiroshi Tamura Toshiyuki Shono 《Journal of Electroanalytical Chemistry》1979,105(2):335-340
Caesium-selective PVC membrane electrodes based on bis(crown ether)s containing benzo-18-crown-6 moieties were prepared using two kinds of plasticizers. Selectivity coefficients for various interfering monovalent ions were determined by the mixed solution method, and were found to relfect the complexing property and extractability of the bis-(benzo-18-crown-6)s. The electrochemical selectivity was also compared with that of the corresponding monocyclic analog and valinomycin. 相似文献
126.
Poly(crown ether)-catalysed derivatization of lower fatty acids with p-bromophenacyl bromide or pentafluorobenzyl bromide has been used for their determination in gaseous samples by gas chromatography (employing either flame-ionization or electron-capture detection). Stontium hydroxide was employed as a base for the derivatization, taking advantage of the fact that a column packed with strontium hydroxide-coated glass beads is very suitable for preconcentration of the fatty acids from ambient air. In situ derivatization of lower fatty acids, preconcentrated on the glass beads as their strontium salts, proceeded nearly quantitatively in acetonitrile. Traces of lower fatty acids in artificial sample gases could be determined successfully using this conventional derivatization followd by direct injection of the reaction mixture into a gas chromatograph. 相似文献
127.
[reaction: see text] We have established an enantioselective synthesis of both C2 symmetric and unsymmetric tetra-ortho-substituted axially chiral biaryls through rhodium-catalyzed double [2 + 2 + 2] cycloaddition (up to >99% ee). This method serves as an attractive new route to enantioenriched tetra-ortho-substituted axially chiral biaryls in view of the one-step access to substrate diynes and tetraynes starting from readily available alkynes. 相似文献
128.
Yoneda K Adachi K Hayami S Maeda Y Katada M Fuyuhiro A Kawata S Kaizaki S 《Chemical communications (Cambridge, England)》2006,(1):45-47
The variable temperature magnetic susceptibility, X-ray crystallography, and M?ssbauer and Raman spectra of a new dinuclear complex-based one-dimensional coordination polymer [[Fe(II)2(NCS)2(mu-bpypz)2](micro-4,4'-bpy)].MeOH demonstrated a steep one-step [HS-HS] to [LS-LS] spin transition. 相似文献
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130.
S. Amano K. Masuda A. Shimoura S. Miyamoto T. Mochizuki 《Applied physics. B, Lasers and optics》2010,101(1-2):213-219
A laser-plasma source for extreme-ultraviolet (EUV) light that uses a rotating cryogenic solid-state Xe target has been characterized. We focused on parameters at the wavelength of 13.5 nm with 2% bandwidth required for an EUV lithography source and investigated improvements of the conversion efficiency (CE). With the drum rotating, there was an increase in CE and less fast ions compared with the case for the drum at rest. It is considered that the Xe gas on the target surface can produce optimal-scale plasma, and satellite emission lines in Xe plasma effectively increase the EUV intensity, and the ion number is decreased by the gas curtain effect. The dependence of CE on the laser wavelength, laser energy and intensity also studied. As a result, the maximum CE was 0.9% at 13.5 nm with 2% bandwidth under the optimal condition. By continuous irradiation of a Nd:YAG slab laser at a repetition rate of 320 Hz and an average power of 110 W, the target continuously generated EUV light with an average power of 1 W at 13.5 nm with 2% bandwidth. The achieved performances provide valuable information for the design of a future EUV lithography source. 相似文献