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991.
A class of non-mesogenic molecules, which as mixtures exhibit monotropic nematic phases, is described. 相似文献
992.
J. W. Lee Y. Takase B. A. Newman J. I. Scheinbeim 《Journal of Polymer Science.Polymer Physics》1991,29(3):273-277
Cold-drawn Nylon-11 films, which were prepared by stretching the melt-quenched films to a draw ratio of 2.8: 1 at room temperature, were found to exhibit an electric displacement versus electric field hysteresis loop. The results confirmed that the Nylon-11 film exhibited ferroelectric behavior at or below room temperature. The coercive fields were 65, 98, 125, 160, and 215 MV/m at 20, 0, ?20, ?40, and ?60°C and the remanent polarization at ?20°C (where there was considerably less dc conduction) was 56 mC/m2. Switching of the polarization was almost completed within 20 ms. 相似文献
993.
X-ray diffraction studies have been undertaken on aqueous solutions of hydroxy propylcellulose (HPC) over a wide range of the scattering vector Q. The experiments revealed only modest differences in local structure on a distance scale ca. 5–300 Å despite the fact that they covered concentrations generally interpreted as ranging from the isotropic (35.1 wt %) to the anisotropic liquid crystalline (LC) phase (53.5 wt %). Several models were used to interpret the small-angle scattering data, and each gave similar structural parameters and extrapolated intensities ( Q → 0) for both solutions. Peaks were observed with d-spacings ca. 12–17 Å in both materials. Wide-angle x-ray scattering (WAXS) showed slightly increased local order over a size range ca. 5–20 Å for the anisotropic solution, and this is consistent with a greater intensity of the 13 Å peak in this material. It is difficult to reconcile these findings with an interpretation of the LC state involving major differences with the isotropic phase and a high degree of orientational order extending over long length scales. 相似文献
994.
995.
S. Yu. Kun V. Yu. Denisov A. V. Vagov 《Zeitschrift für Physik A Hadrons and Nuclei》1997,359(3):257-262
We employ the statistical reactions with memory approach to study oscillating excitation functions in the 28 Si(E lab = 120–126.75 MeV)+64 Ni strongly dissipative reaction and the time evolution of the collision process. The nonself-averaging of the oscillations in the excitation functions is interpreted as indication of quantum chaos and damping of the coherent nuclear rotation in dissipative heavy-ion collisions. 相似文献
996.
997.
G. Cevolani 《Il Nuovo Cimento C》1991,14(2):203-206
Summary Time variations of the semi-diurnal and diurnal tides observed at Budrio (45°N, 12°E) in the wind structure of the lower thermosphere
((80÷110) km) throughout the period 1976–1990 are herewith represented as monthly contours of both amplitudes and phasesvs. height. The semi-diurnal tide has more marked seasonal variations, showing amplitudes generally larger than the diurnal
ones ((10÷30) m/svs. (5÷15) m/s). The vertical wavelengths are longer in summer than in winter, at least below 100 km. Agreement with new numerical
models for semi-diurnal tide at 50°N appears to be satisfactory. 相似文献
998.
999.
1000.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 56, No. 2, pp. 268–273, February, 1992. 相似文献