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91.
92.
Tetraarylthiophenes were prepared by regioselective Suzuki cross-coupling reactions of tetrabromothiophene. 相似文献
93.
The transverse momentum dependence of the parton distribution function and the Drell-Yan cross section is studied in detail in the asymptotically free scalar field theory in six dimensions. In the context of the renormalization group approach of Collins, particular attention is devoted to the transition between the small qT formula (due to multe-quanta effects) and the large qT formula (due to single hard-quantum emission). The calculation represents a case study of the application of the renormalization group method and provides a guide to the corresponding study in QCD. 相似文献
94.
95.
N. Chan Tung Y. Caratini C. D'Anterroches J. L. Buevoz 《Applied Physics A: Materials Science & Processing》1988,47(3):237-247
Rapid Thermal oxidation (RTO) of silicon has been investigated in the temperature range 1000° to 1250°C for an oxidation time of 5 to 60 s. The fairly extensive kinetics data show that linear growth occurs with an activation energyE
a of 1.4 eV. Rapid thermal nitridation of SiO2 (96 Å) has been performed at three different temperatures: 1150°, 1200°, and 1250°C for a nitridation time up to 150 s. The characteristics of both materials have been investigated by capacitance-voltage, current-voltage, high resolution transmission electron microscopy and Auger spectroscopy. The results will be discussed with special emphasis on breakdown field statistics. The influence of Rapid Thermal Annealing (RTA) on the characteristics of both oxide and nitrided oxide will also be presented. A simulation model of a rapid thermal processing machine is presented with particular attention to the formation of slip lines. The theoretical results are in good agreement with those obtained experimentally. 相似文献
96.
L. H. Tung 《Journal of Polymer Science.Polymer Physics》1969,7(1):47-55
A method of determining the distribution of branching in polydisperse polymer samples is proposed. This method uses data from concurrent gel permeation chromatography and sedimentation-velocity experiments. Tedious fractionation, which must precede other methods of determining long-chain branching, is eliminated. An example of use of the method on the data of a sample of styrene–divinylbenzene copolymer is given. 相似文献
97.
98.
The Nachtmann moments of deep inelastic scattering structure functions are required by kinematics to contain a so far neglected threshold factor which is dependent on both n and q2. Its presence significantly affects the “moment analysis” in the usual QCD phenomenology and it resolves the difficulties connected with improper threshold behavior of the “ξ-scaling” analysis of structure functions. 相似文献
99.
Graft distribution functions have been derived from random grafting statistics. Among the functions, the weight fraction of ungrafted backbone chains, the molecular weight distribution of the ungrafted backbone chains and the GPC apparent molecular weight distribution of the graft copolymer have been found to agree with experimental values determined for a graft copolymer system in which grafting was expected to be random. The other functions, which are not directly measurable, are therefore probably also correct. In analytical work the entire set of graft distribution functions may be computed for a graft copolymer system from the following experimental data: (1) molecular weight distribution of the starting backbone chains; (2) the chemical composition of the mixture of the graft copolymer and ungrafted backbone; (3) the graft side-chain molecular weight distribution, which may be assumed to be identical to that of the ungrafted homopolymer separable from the reaction mixture. 相似文献
100.