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571.
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The pressure-induced changes in the coordination structure of Cd2+ and Pb2+ were examined by measuring the ESR spectra of γ-ray-induced Cd+ and Pb3+ centers. The s-character of the magnetic electron in the centers increased on densification and was estimated from the analysis of the hyperfine absorption due to a 207Pb3+ and 111Cd+ and 113Cd+. The increase in the s-character means that the strength of both Pb2+O and Cd2+O bonds was reduced upon densification and that the coordination number of Cd2+ and Pb2+ increased. The coordination sphere of Cd2+, which responds more sensitively than that of Pb2+ to the change in chemical environments, was more heavily compressed than that of Pb2+. 相似文献
574.
575.
T. C. Clarke K. K. Kanazawa V. Y. Lee J. F. Rabolt J. R. Reynolds G. B. Street 《Journal of Polymer Science.Polymer Physics》1982,20(1):117-130
Poly(p-phenylene sulfide) (PPS) is a melt- and solution-processible polymer which on treatment with AsF5 forms a blue-black material with a conductivity of 1–10 Ω?1 cm?1. Thermopower measurements indicate that the resulting polymer is p type, consistent with partial oxidation of the PPS by the AsF5. The rate and extent of this doping process prove to be particularly sensitive to the degree of crystallinity of the starting polymer. There is also evidence of crosslinking of the polymer chains during the reaction with AsF5. The details of both the chemistry and physics of the doping of PPS and several of its derivatives are presented. 相似文献
576.
Nonlinear optical properties are shown by the smectic phase formed by simple dialkyl phosphonium salts. The molecules form into layers, featuring ion pairs separated by insulating glassy alkyl coating to produce a spontaneous polarization (P(s)) in the sheets (see picture). Applications of this material are currently leading to the development of novel electrical and electrooptical devices. 相似文献
577.
578.
We have proposed the evolution mechanism of the Fermi arc with increasing of hole-doping in high-Tc cuprates, taking into account the restoration of spontaneous symmetry breaking through the polarization bubble by the hole–electron propagator. 相似文献
579.
We evaluated 15 healthy participants by assessing their maintenance of postural control while standing on a platform stabilometer for 1 min under the following conditions: eyes open; eyes open with + 3.00 D on both eyes on same directions (45, 90, 135, 180 degree axis); right eye on 45 degree axis and left eye on 135 degree axis (inverted V-pattern), and right eye on 135 degree axis and left eye on axis 45 degree axis (V-pattern). The differences in the linear length, area and maximum velocity of center of pressure during postural control before and after the six types of positive cylinder-oriented axes were analyzed. Comparing the antero-posterior lengths and antero-posterior maximum velocities, there were significant differences between the V-pattern condition and the six other conditions. Astigmatic defocus in the antagonistic axes conditions, particularly the V-pattern condition, affects postural control of antero-posterior sway (143/150). 相似文献
580.
Effect of quenching rate and annealing on ESR of Cu2+ and γ-induced Cd+ in low alkali borate glasses
A new ESR hyperfine structure (hfs) of Cu2+ was detected in moderately (cooling rate ≈ 3 K/s) and rapidly (103–105K/s) quenched borate glasses with Na2O content smaller than 5 mol% in addition to the already reported three patterns, spectra I, II and III, for the moderately quenched borate glasses with 5 ? [Na2O]?13, 20 ? [Na2O] ?37 and 55 ? [Na2O] ? 75, respectively. The ESR parameters of this spectrum were much the same as those of II, but a significant difference was observed between thermal stabilities of these spectra. The newly observed spectrum was named spectrum II′. A superposition of spectra II′ and I was seen in low alkali borate glasses ([Na2O] ? 5 mol%). The relative intensity of II′ to I increased remarkably with increasing quenching rate of the melts and with decreasing alkali content under the same quenching condition. In addition, spectrum II′ was found to relax into I upon thermal annealing of the glasses. Similar changes were observed also in ESR of the γ-induced Cd+ with 5s1 electronic configuration. A tentative model to account for the spectral changes was proposed on the basis of the characteristics of B—O bonding. 相似文献