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11.
The hitherto analyses of elastic collisions of charged nucleons involving common influence of Coulomb and hadronic scattering have been based practically on West and Yennie formula. However, this approach has been shown recently to be inadequate from experimental as well as theoretical points of view. The eikonal model enabling to determine physical characteristics in impact parameter space seems to be more pertinent. The contemporary phenomenological models admit, of course, different distributions of collision processes in the impact parameter space and cannot give any definite answer. Nevertheless, some predictions for the planned LHC energy that have been given on their basis may be useful, as well as the possibility of determining the luminosity from elastic scattering. 相似文献
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Vladimí ra Novotn V ra Hamplov Miroslav Ka par Milada Glogarov Damian Pociecha 《Liquid crystals》2005,32(9):1115-1123
The synthesis and physical properties of bent-shaped molecules with ester linkages and methoxy substitution on a non-central ring are presented. Terminal chains of most mesogens contain a group with double bond, which promotes polymerization. In all the compounds studied a B2 phase just below the isotropic phase has been found. Polarization current profiles indicate that this phase is antiferroelectric, and dielectric spectroscopy data with a pronounced high frequency mode support this fact. For several compound chirality switching from racemic to the homochiral state was seen after application of a low frequency a.c. field. Another phase, which could be assigned to the B7 family, appears below the B2 phase on cooling. 相似文献
14.
F. Soška F. Beneš S. Jura B. Gross Z. šimša F. Kosek J. Horák J. Kašpar K. čermák J. Lipták M. Ryba E. F. Holländer A. Havránek E. Havránková A. Kochanovská J. Sommer F. Vilím P. Lukáš C. Rumler S. Kadečková F. Vávra M. Matyáš J. Beneš J. Kučera L. DvoŘák Z. KudĚlásek J. Hájek A. Marek Z. Malec J. Janků B. Sojka L. Karmazin M. Ryšavá L. Janko K. Huml 《Czechoslovak Journal of Physics》1961,11(11):852-862
15.
Maja Stojanović Alexej Bubnov Dusanka Ž. Obadović Vĕra Hamplová Miroslav Kašpar Miroslav Cvetinov 《Phase Transitions》2013,86(4):380-390
Studies of structural and phase properties obtained on several ferroelectric liquid crystalline materials with 2-alkoxypropionate group used as a chiral centre and without any lateral substitution are presented. In dependence on the chiral chain length these compounds exhibit the cholesteric N* phase, the ferroelectric smectic C* and a low-temperature SmX phase. Values of the spontaneous polarization and spontaneous tilt angle have been determined within the whole range of the SmC* phase. A low-temperature SmX phase has been identified as the orthogonal hexatic SmB* phase. The molecular parameters, namely the layer spacing in the SmC* and SmB* phases and the average intermolecular distances (D) between neighbouring parallel molecules in all investigated phases have been determined using the results of the X-ray diffraction obtained on non-oriented samples. The effect of the chiral chain length on mesomorphic, structural and physical properties of the studied ferroelectric liquid crystalline materials is discussed. 相似文献
16.
V. Novotn M. Ka par V. Hamplov M. Glogarov I. Rychetský D. Pociecha 《Liquid crystals》2004,31(8):1131-1141
Compounds with differing numbers of lactate units in the chiral part were synthesized. For all materials, at least two smectic phases were found. In addition to the SmA, the SmC* and/or the tilted hexatic SmI*(F*) phase appear according to the length of the non-chiral alkyl chain. For the shortest non-chiral chain, a direct transition from the SmA phase to the SmI*(F*) phase has been discovered and studied. For compounds with the 2-(S)-methylbutyl alkyl chain and two lactate units in the chiral part the antiferroelectric SmC*A phase occurs. The ferroelectric character of the hexatic phase has been confirmed even just below the SmC*A phase. 相似文献
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Sabbah par Raphaël Lahcen El Watik 《Journal of Thermal Analysis and Calorimetry》1990,36(7-8):2299-2312
Several organic compounds as new reference materials for temperature and energy calibration of DTA and DSC appartuses were studied in the range of temperature 300–600 K.
Zusammenfassung Im Temperaturbereich 300–600 K wurden einige organische Verbindungen als neue Referenzsubstanzen für die Temperatur- und Energieeichung bei DTA und DSC untersucht.相似文献
19.
A. Gosman V. Kliský J. Kašpar P. Vodolan 《Journal of Radioanalytical and Nuclear Chemistry》1988,121(2):375-383
The possibility of preparation of237U by the238U(, n)237U reaction, realized by irradiation of UO3 on the microtron, has been verified. The relation between yields for (, n) and (, f) reaction was determined. The activated uranium was separated from fission products by extraction into diethyl ether.237U was used for the study of the kinetics of heterogeneous isotope exchange in the system aqueous solution of UO2(NO3)2 — ion exchanger Wofatit CA-20 in UO
2
2+
form. The experimental results were evaluated by a model based on particle diffusion with simultaneous isotope exchange between two uranium forms in the ion exchanger. 相似文献
20.