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1.
It is shown that the most recent measurements of differential cross-section at small momentum transfers, integrated and total
cross-sections, and the slope of np elastic scattering from 100 to 400 GeV/c are successfully fitted by using the simple Regge
pole model proposed by the authors several years ago. 相似文献
2.
R. J. Jiménez‐Riobóo R. Cuscó N. Domènech‐Amador C. Prieto T. Yamaguchi Y. Nanishi L. Artús 《固体物理学:研究快报》2012,6(6):256-258
The surface acoustic wave velocity in InN has been experimentally determined by means of Brillouin scattering experiments on c ‐ and m ‐face epilayers. From simulations based on the Green's function formalism we determine the shear elastic constants c66 and c44 and propose a complete set of elastic constants for wurtzite InN. The analysis of the sagittal and azimuthal dependence of the surface acoustic wave velocity indicates a slightly different elastic behavior of the m ‐face sample that basically affects the c44 elastic constant. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
3.
Jacob Philip 《Pramana》1987,29(4):391-398
The equations of motion for the propagation of finite amplitude elastic waves in crystals of tetragonal symmetry have been
derived starting from the expression for the elastic strain energy. The equations have been solved for a finite amplitude
sinusoidal wave propagating along the pure mode directions which are [100], [110] and [001] for the tetragonal group TI. The
solutions corresponding to longitudinal wave propagation yield expressions for the amplitudes of the fundamental and generated
second harmonic for these directions in terms of certain combinations of second and third order elastic constants of the medium.
The results will aid the experimenter to determine these constants using ultrasonic harmonic generation technique. 相似文献
4.
TU Mei & HUANG Yaoxiong Institute of Biomedical Engineering Jinan University Guangzhou China Correspondence should be addressed to Huang Yaoxiong 《中国科学G辑(英文版)》2004,47(1)
Theelasticconstantsandtheviscositycoefficientsarethekeyparametersforthephysicalpropertiesofnematicliquidcrystals(LCs)[1,2],fortheyarecorrespondingtothethresholdvoltageandtherespondingtimeofliquidcrystaldisplaydevices[3,4].Sofarnotechniquethatcansimultaneouslymeasurethetwoparametersinsituhasbeenreported.TheelasticconstantsandviscositycoefficientsofnematicLCsatthepresentaremeasuredusingdifferentmethodsindependently.TheviscositycoefficientsisgenerallymeasuredwithOstwaldviscosimeter,andtheelasti… 相似文献
5.
Regge pole plus cut model for proton-antiproton elastic scattering at collider and tevatron energies
The Regge pole plus cut model has been used to explain the data at the collider energies √s=546 and 630 GeV and the most recent differential cross-section results at √s=1.8 TeV. Predictions of the model at 1.8 and 40 TeV are compared with those of Bourrelyet al. 相似文献
6.
The laser light scattering technique for non-invasivein situ simultaneous measurements on elastic constants and viscosity coefficients of nematic liquid crystals is introduced. By measuring
the autocorrelation function of the scattered light from nematic liquid crystals at different scattering angles, the splay
and twist elastic constantsK
11 andK
22 are obtained from the amplitudes of the autocorrelation function, and the viscosity coefficients ofη
Splay andη
Twist are determined using the viscoelastic ratiosK
11/η
Splay andK
22
η
Twist from the telaxation parameters of the two modes. 相似文献
7.
8.
Determination of elastic,piezoelectric,and dielectric constants of an R:BaTiO<sub>3</sub> single crystal by Brillouin scattering 下载免费PDF全文
From the sound velocity measured using the Brillouin scattering technique,the elastic,piezoelectric,and dielectric constants of a high-quality monodomain tetragonal Rh:BaTiO3 single crystal are determined at room temperature.The elastic constants are in fairly good agreement with those of the BaTiO3 single crystal,measured previously by Brillouin scattering and the low-frequency equivalent circuit methods.However,their electromechanical properties are significantly different.Based on the sound propagation equations and these results,the directional dependence of the compressional modulus and the shear modulus of Rh:BaTiO3 in the(010) plane is investigated.Some properties of sound propagation and electromechanical coupling in the crystal are discussed. 相似文献
9.
Effective equations of motion of a surface atom placed in an anharmonic surface potential are derived for three kinds of substrates (i) continuous dispersionless, (ii) discrete with nearest neighbours harmonic interactions, and (iii) a substrate showing a strong spatial dispersion. The resulting equations of motion are differential equations in the case (i) and Volterra Integro-Differential Equations (VIDE) in the cases (ii) and (iii). Examples of non-linear surface response to phonons coming from the bulk are given for the dispersionless substrate. 相似文献
10.
11.
Hiroshi Fukui Tomoo Katsura Takahiro Kuribayashi Takuya Matsuzaki Akira Yoneda Eiji Ito Yasuhiro Kudoh Satoshi Tsutsui Alfred Q. R. Baron 《Journal of synchrotron radiation》2008,15(6):618-623
Inelastic X‐ray scattering (IXS) measurements have been performed on an MgO single crystal in order to evaluate IXS as a methodology for accurate and precise determination of elastic constants and sound velocities. By performing the IXS experiment using a 12‐analyzer array, the complete set of single‐crystal elastic constants of MgO were determined to a precision better than 0.8% (sound velocities to better than 0.2%). The results are consistent with values in the literature. The precision and accuracy of this work, which is significantly better than other published work to date, demonstrates the potential of IXS in determining elastic properties. 相似文献
12.
Elastic scattering cross-sections of lead, tantalum and molybdenum were determined with the help of a Ge (Li) detector for
1.17 and 1.33 MeV rays between 30° and 115°. Theoretical evaluations of the cross-sections are based on a coherent addition
of the well-known nuclear Thomson scattering amplitudes, the Rayleigh amplitudes calculated by Kissel and Pratt and the Delbrück
amplitudes given by Papatzacos and Mork. The fairly good agreement between experiment and theory reveals the importance of
the real Delbrück amplitudes. However, the experimental results in the 30–60° range tend to lie slightly but systematically
below the calculated cross-sections.
Work supported in part by a grant from the National Bureau of Standards, Washington, DC under the SFCP programme. 相似文献
13.
The concepts of complex electron atomic scattering factors and principles for evaluating these factors are discussed and their applicability is examined. Numerical procedures and routines for calculating these factors are described, and for 98 neutron atoms and 109 ions the real part of the electron atomic scattering factors were parameterized using 10 and eight parameters, respectively. Procedures for constructing two and three dimensional scattering potentials using the complex atomic scattering factors are illustrated with examples; effects of thermal vibrations of the crystal lattice are discussed. 相似文献
14.
15.
The elastic scattering properties in a mixture of sodium and cesium atoms are investigated at cold and ultracold temperatures. Based on the accurate interatomic potential for the NaCs mixture, the interspecies s-wave scattering lengths, the effective ranges and the p-wave scattering lengths are calculated by the quantal method and the semiclassical method, respectively. The s-wave scattering lengths are 512.7a0 for the singlet state and 33.4a0 for the triplet state. In addition, the spin-change and elastic cross sections are also calculated, and the g-wave shape resonance is found in the total elastic cross sections. 相似文献
16.
Total attenuation cross sections of copper and silver have been measured in the energy range 5 to 85 keV in a narrow beam
good geometry set up using X- andγ-rays emitted from radio isotopes, by employing a high resolution hyper pure germanium detector. From the measured values,
the photoeffect cross-sections have been derived by subtracting a small contribution of the sum of the theoretical coherent
and incoherent scattering cross sections. The photoeffect cross-sections so obtained are found to be in better agreement with
the unrenormalized values of Scofield [10]. These photoeffect cross-sections have been used to evaluate the dispersion corrections
(also called anomalous scattering factors)f
+ andf″ for the forward Rayleigh scattering amplitude by a numerical evaluation of the dispersion integral that relates them at the
energies at which the cross-sections have been measured. To thef
+ values so obtained, the relativistic corrections proposed by different investigators are included separately and the valuesf′ so obtained are compared with the available data and discussed. Possible conclusions are drawn from the present study. 相似文献
17.
V. N. Manuilov V. G. Pavelev 《International Journal of Infrared and Millimeter Waves》1997,18(12):2335-2342
The method of calculation of the circular oversized waveguide filled in with insulator using the method of plane cross-section
(PCS) is developed. The wave scattering on the output insulator window for powerful occilator is investigated. 相似文献
18.
Abstract Preliminary results of neutron diffraction and inelastic neutron scattering studies under high pressure of normal (D-O) and deuterated (D-12) cyclohexane are presented. 相似文献
19.
Determination of elastic, piezoelectric, and dielectric constants of an R:BaTiO3 single crystal by Brillouin scattering 下载免费PDF全文
From the sound velocity measured using the Brillouin scattering technique, the elastic, piezoelectric, and dielectric constants of a high-quality monodomain tetragonal Rh:BaTiO3 single crystal are determined at room temperature. The elastic constants are in fairly good agreement with those of the BaTiO3 single crystal, measured previously by Brillouin scattering and the low-frequency equivalent circuit methods. However, their electromeehanical properties are significantly different. Based on the sound propagation equations and these results, the directional dependence of the compressional modulus and the shear modulus of Rh:BaTiO3 in the (010) plane is investigated. Some properties of sound propagation and electromechanical coupling in the crystal are discussed. 相似文献
20.
In this paper, the statistical moment method (SMM) has been developed to study the pressure dependence of thermodynamic quantities of germanium and silicon crystals. We have derived the analytical expressions of the pressure-dependent parallel mean-square relative displacement (MSRD) or extended X-ray absorption fine structure (EXAFS) Debye–Waller factor, mean-square displacement (MSD) as well as lattice constant and volume change of diamond-type crystals. Numerical calculations performed for these semiconductors up to 11 GPa are found to be in good and reasonable agreement with available experimental data as well as with previous theoretical studies. Our results indicate that the SMM can be efficiently used for determining the relative change of the pressure-dependent MSRDs of germanium and silicon semiconductors. The research also shows the advantage of SMM on studying other thermodynamic properties of materials under high pressures. 相似文献