共查询到20条相似文献,搜索用时 46 毫秒
1.
Atsushi Mori Yoshihisa Suzuki Shin-Ichiro Yanagiya Tsutomu Sawada Kensaku Ito 《Molecular physics》2013,111(10):1377-1383
Disappearance of a stacking fault in the hard-sphere crystal under gravity, such as reported by Zhuet al. [Nature 387, 883 (1997)], has successfully been demonstrated by Monte Carlo simulations. We previously found that a less ordered (or defective) crystal formed above a bottom ordered crystal under stepwise controlled gravity [Moriet al. J. Chem. Phys. 124, 174507 (2006)]. A defect in the upper defective region has been identified with a stacking fault for the (001) growth. We have looked at the shrinking of a stacking fault mediated by the motion of the Shockley partial dislocation; the Shockley partial dislocation terminating the lower end of the stacking fault glides. In addition, the presence of crystal strain, which cooperates with gravity to reduce stacking faults, has been observed. 相似文献
2.
On the spontaneous-coherence-transfer-induced sign change of a sub-natural-width nonlinear resonance
A simple theoretical model is proposed which describes the positive sign of the nonlinear absorption resonances in the experiments
of Akul’shin et al. [Phys. Rev. A 57, 2996 (1998)]. An analytical expression for the linear response to a weak probe field is obtained in the weak-saturation
limit. It is shown that the positive sign of sub-natural-width resonances is due to the spontaneous transfer of low-frequency
coherence from an excited level to the ground state.
Pis’ma Zh. éksp. Teor. Fiz. 69, No. 11, 776–781 (10 June 1999) 相似文献
3.
The four-point correlation function has been studied in Liouville field theory. If one of the fields is degenerate, such a
function is described in terms of Coulomb integrals. Some nontrivial relations for these integrals have been found that can
be used to obtain new exact results in conformal field theory. In particular, a four-point correlation function has been calculated
in minimal quantum gravity. The result agrees with the results obtained recently by different methods [A. A. Belavin and A.
B. Zamolodchikov, JETP Lett. 82, 7 (2005); Theor. Math. Phys. 147, 729 (2006); A. B. Zamolodchikov, Theor. Math. Phys. 142, 183 (2005); I. K. Kostov and V. B. Petkova, Theor. Math. Phys. 146, 108 (2006)].
The text was submitted by the authors in English. 相似文献
4.
S.M.S. da Costa M.H.F. Bettega 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》1998,3(1):67-71
We report elastic integral, momentum transfer and differential cross sections for electron scattering by N2O for energies up to 50 eV. These results were obtained at the static-exchange approximation with the Schwinger Multichannel
Method with Pseudopotentials [M.H.F. Bettega, L.G. Ferreira and M.A.P. Lima, Phys. Rev. A 47, 1111 (1993)]. In general our results show good agreement with experimental data and with other theoretical results but some
discrepancies are found. We have also found a shape resonance around 4 eV in agreement with previous calculations using the R-matrix Method of Sarpal et al. [J. Phys. B 29, 857 (1996)]. On the other hand, the existence of a resonance at about 13 eV, clearly seen by the Schwinger Variational Iterative Method [Michelin et al., J. Phys. B 29, 2115 (1996)], can not be confirmed by our calculations. At this energy, our cross sections show a broad bump with no clear resonant behavior given by the eigenphase sum.
Received: 13 November 1997 / Revised: 13 March 1998 / Accepted: 9 April 1998 相似文献
5.
W. Ekardt W.-D. Schöne R. Keyling 《Applied Physics A: Materials Science & Processing》2000,71(5):529-535
Experience has shown that theoretically determined lifetimes of bulk states of hot electrons in real metals agree quantitatively
with the experimental ones, if theory fully takes into account the crystal structure and many-body effects of the investigated
metal, i.e., if the Dyson equation is solved at the ab initio level and the effective electron–electron interaction is determined beyond the plasmon-pole approximation. Therefore the
hitherto invoked transport effect [Knoesel et al.: Phys. Rev. B 57, 12812 (1998)] does not seem to exist. In this paper we show that likewise neither virtual states [Hertel: et al. Phys. Rev.
Lett. 76, 535 (1996)] nor damped band-gap states [Ogawa: et al.: Phys. Rev. B 55, 10869 (1997)] exist, but that the hitherto unexplained d-band catastrophe in Cu [Cu(111), Cu(110)] can be naturally resolved
by the concept of the transient exciton. This is a new quasiparticle in metals, which owes its existence to the dynamical character of dielectric screening at the microscopic level. This means that excitons, though they do not exist under stationary
conditions, can be observed under ultrafast experimental conditions.
Received: 30 March 2000 / Accepted: 2 September 2000 / Published online: 12 October 2000 相似文献
6.
F. Monroy F. Ortega R.G. Rubio 《The European Physical Journal B - Condensed Matter and Complex Systems》2000,13(4):745-754
The thermoelastic behaviour of polyvinylacetate monolayers spread on an aqueous subphase has been studied using rheological
data previously published (Monroy et al., Phys. Rev. E 58, 7629 (1998)). The results show fluid-like viscoelastic behaviour well above a transition temperature , while at lower temperatures a soft solid-like behaviour emerges. The correlation between thermodynamic and elastic properties
below can be described in terms of scaling laws.
Received 12 January 1999 and Received in final form 11 June 1999 相似文献
7.
A quasiharmonic model calculation for non-markovian far-infrared spectra of HCl in Kr and Xe liquids
The far-infrared spectra (0–200 cm?1) of dilute solutions of HCl in liquid Kr and Xe have been calculated by applying of a non-markovian spectral theory called PTOC (partial time ordering cumulants) and by using a quasiharmonic model for the liquid structure recently reported by us (A. Calvo Hernández et al., 1987, J. chem. Phys., 86, 4597) and successfully applied to HCl?Ar solution (Ibid., 86, 4607). The bath correlation functions which appear in the spectral theory involve a reduced set of parameters regarding both the HCl?Kr and HCl?Xe interactions and the liquid structure. From comparison between theoretical and experimental spectra it is possible to deduce quantitative values for the above parameters. The pronounced rotational fine structure of the experimental spectra for HCl in Kr and Xe liquids is quite well explained by the actual model. 相似文献
8.
A mixture of two types of super-paramagnetic colloidal particles with long-range dipolar interaction is confined by gravity
to the flat interface of a hanging water droplet. The particles are observed by video microscopy and the dipolar interaction
strength is controlled via an external magnetic field. The system is a model system to study the glass transition in 2D, and
it exhibits partial clustering of the small particles (N. Hoffmann et al., Phys. Rev. Lett. 97, 078301 (2006)). This clustering is strongly dependent on the relative concentration of big and small particles. However, changing the interaction strength reveals that the clustering does not depend on the interaction strength. The partial clustering scenario is quantified using Minkowski functionals and partial structure factors. Evidence that partial clustering prevents global crystallization is discussed. 相似文献
9.
R. I. Kurinnaya M. V. Zgolich L. E. Popov V. A. Starenchenko 《Russian Physics Journal》1997,40(5):405-410
Dislocation combinations formed as a result of interaction between a glissileBσ,d Shockley partial dislocation with reacting undissociated forest dislocations are considered. The value of the parameters
characterizing the strength <k> of the dislocation combinations, the probability βr of their formation, and the interaction intensity αr of the reacting dislocations are determined for an orientation of the [100] deformation axis of an FCC single crystal for
all components of the dislocation loop.
Tomsk State Architectural-Building Academy. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 5, pp. 3–8,
May, 1997. 相似文献
10.
Dong Shu-bao Feng Er-yin Huang Wu-ying Cui Zhi-feng 《Czechoslovak Journal of Physics》2005,55(1):27-33
Molecular reaction dynamics of Cl + H2 (D2) has been studied on the latest analytical potential energy surface called BW3 using the Monte Carlo quasi-classical trajectory method. Excitation functions, differential cross sections and angular distributions of HCl and DCl products have been calculated. The excitation functions of the Cl (2P3/2) + n-H2 and Cl(2P3/2) + n-D2 reactions are also studied. The results are compared with those of quasi-classical trajectory [M. Alagia et al.: Phys. Chem. Chem. Phys. 2 (2000); F. J. Aoiz et al.: J. Phys. Chem. 100 (1996)], quantum mechanical (QM) calculations [F. J. Aoiz et al.:J. Chem. Phys. 115 (2001)] and experimental data [S. H. Lee et al.: J. Chem. Phys. 110 (1999); F. Dong et al.: J. Chem. Phys. 115 (2001)]. Discussions are given to some new results. 相似文献
11.
V. A. Belyakov 《JETP Letters》1999,70(12):811-818
It has been predicted by Shelton and Shen [Phys. Rev. A 5, 1867 (1972)] and observed by Kajikawa et al. [Jpn. J. Appl. Phys. Lett. 31, L679 (1992)] and Yamada et al. [Appl. Phys. B 60, 485 (1995)] that the efficiency of nonlinear-optical frequency conversion increases significantly in a nonlinear periodic
medium and, accordingly, the intensity of the generated harmonic increases as the fourth power of the sample thickness, as
opposed to the square law observed in homogeneous media. In this paper it is shown that the same enhancement of the efficiency
of nonlinear-optical frequency conversion in a nonlinear periodic medium can be achieved using an ordinary pump wave in the
form of a plane wave when both the pump wave and the harmonics are diffracted by the periodic structure of the nonlinear medium.
The phenomenon is analyzed quantitatively in the example of second-harmonic generation.
Pis’ma Zh. éksp. Teor. Fiz. 70, No. 12, 793–799 (25 December 1999) 相似文献
12.
M. V. Takook H. Pejhan M. Reza Tanhayi 《The European Physical Journal C - Particles and Fields》2012,72(7):1-11
From the group theoretical point of view, it is proved that the theory of linear conformal gravity should be written in terms of a tensor field of rank-3 and mixed symmetry (Binegar et al. in Phys. Rev. D 27:2249, 1983). We obtained such a field equation in de Sitter space (Takook et al. in J. Math. Phys. 51:032503, 2010). In this paper, a proper solution to this equation is obtained as a product of a generalized polarization tensor and a massless scalar field and then the conformally invariant two-point function is calculated. This two-point function is de Sitter invariant and free of any pathological large-distance behavior. 相似文献
13.
In the context of molecular dynamics simulations of rare events, the application of constraints on a suitable reaction coordinate has often been found useful for sampling of the free energy barrier. The efficiency of these calculations is hampered by geometrical difficulties, related to the metric factor and inertial forces. Some years ago Mulders et al. [1996, J. chem. Phys., 104, 48691 suggested a way to simplify the approach. Their idea was demonstrated shortly afterwards by Sprik and Ciccotti [1998, J. chem. Phys., 109, 77371. The present paper extends these results to vector reaction coordinate and molecular systems modelled with holonomic constraints. 相似文献
14.
It has recently been claimed that the dynamics
of long-wavelength phason fluctuations has been observed in
i-AlPdMn quasicrystals [S. Francoual et al.
Phys. Rev. Lett. 91, 225501 (2003);
A. Létoublon et al. 54, 753 (2001)]. We will show that
the data reported call for a more detailed development of
the elasticity theory of Jarić and Nelsson [M.V. Jarić and D.R. Nelsson, Phys. Rev. B 37,
4458 (1988)]
in order to determine the nature of small phonon-like atomic displacements
with a symmetry that follows the phason elastic constants.
We also show that a simple model with a single diffusing tile is sufficient
to produce a signal that (1) is situated at a “satellite position”
at a distance q from each Bragg peak; that (2) has an intensity that
scales with the intensity of the corresponding Bragg peak;
(3) falls off as 1/q2; and (4) has a time decay constant that is proportional to 1/Dq2.
It is thus superfluous to call for a picture of “phason waves” in order to explain such data, especially as such “waves” violate
many physical principles. 相似文献
15.
VICTOR TEBOUL 《Molecular physics》2013,111(11):1637-1647
The two-, three- and four-body effective collision induced scattering spectral line shapes are calculated for dense gaseous krypton using the pairwise additivity (PA) approximation and different polarizability models. These spectra and several interaction induced spectra calculated at various densities are compared with the experimental measurements of Barocchi et al. [1988, Europhys. Lett., 5, 607]. The potential effect on the spectrum is found to be weak. The results obtained with the Meinander et al. [1986, J. chem. Phys., 84, 3005] empirical polarizability model and molecular dynamics fit well the experimental two- and three-body spectral shapes. The irreducible contribution to the spectral shape is evaluated using the dipole induced dipole irreducible polarizability [buckingham, A. D., and Hands, I. D., 1991, Chem. Phys. Lett., 185, 544]. This contribution is found to be relatively weak for the anisotropic spectra in the frequency and density range studied, explaining the good agreement between the pairwise approximation calculations and the experimental data. The spectra radiated by the quasi-molecules Kr2, Kr3, and Kr4 (the total spectrum within the PA approximation) are also simulated. 相似文献
16.
Marchildonet al. [Phys. Rev. D
27, 1740 (1983)] expressed criticisms about old versions of some approaches to the theory of tachyons. We refute those criticisms somewhatbriefly, since suitable answers werealready present in the literature at the time when the paper here commented upon was being prepared. 相似文献
17.
Josephson oscillation of a superfluid Fermi gas 总被引:1,自引:0,他引:1
S. K. Adhikari 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2008,47(3):413-419
Using the complete numerical solution of a time-dependent
three-dimensional mean-field model we
study the Josephson oscillation of a superfluid Fermi gas (SFG) at zero temperature formed in a combined axially-symmetric
harmonic plus one-dimensional periodic optical-lattice (OL) potentials after displacing the harmonic trap along the axial
OL
axis. We study the dependence of Josephson frequency on the strength of the OL potential. The Josephson frequency decreases
with increasing strength as found in the experiment of Cataliotti et al. [Science 293, 843 (2001)] for a Bose-Einstein condensate and of the experiment of Pezzè et al. [Phys. Rev. Lett. 93, 120401 (2004)] for an ideal Fermi gas. We demonstrate a
breakdown of Josephson oscillation in the SFG for a large displacement
of the harmonic trap. These features of Josephson oscillation of a SFG can be tested experimentally. 相似文献
18.
B. Audoin M. Perton N. Chigarev C. Rossignol 《The European physical journal. Special topics》2008,153(1):235-237
Investigation of thin metallic film properties by means
of picosecond ultrasonics [C. Thomsen et al., Phys. Rev. Lett. 53, 989 (1984)] has been under the scope of several studies.
Generation of longitudinal and shear waves [T. Pézeril et al., Phys. Rev. B 73, 132301 (2006); O. Matsuda et al., Phys. Rev. Lett. 93, 095501 (2004)] with a wave vector normal
to the film free surface has been demonstrated. Such measurements cannot
provide complete information about properties of anisotropic films. Extreme
focusing of a laser pump beam (≈0.5 μm) on the sample surface
has recently allowed us to provide evidence of picosecond acoustic
diffraction in thin metallic films (≈1 μm) [C. Rossignol et al., Phys. Rev. Lett. 94, 166106 (2005)]. The resulting
longitudinal and shear wavefronts propagate at group velocity through the
bulk of the film. To interpret the received signals, source directivity
diagrams are calculated taking into account material anisotropy, optical
penetration, and laser beam width on the sample surface. It is shown that
acoustic diffraction increases with optical penetration, so competing with
the increasing of directivity caused by beam width. Reflection with mode
conversion at the film-substrate interface is discussed. 相似文献
19.
20.
A theoretical explanation is given for the “unexpected” behavior recently observed in the radiation spectrum of ultrarelativistic
electrons in a thin layer of matter in an experimental investigation of the Landau-Pomeranchuk-Migdal effect at SLAC [S. R.
Klein et al., Preprint SLAC-6378, Stanford (1993); P. L. Anthony et al., Phys. Rev. Lett. 75, 1949 (1995)].
Pis’ma Zh. éksp. Teor. Fiz. 63, No. 11, 837–840 (10 June 1996) 相似文献