共查询到20条相似文献,搜索用时 15 毫秒
1.
A. K. Murtazaev M. K. Ramazanov M. K. Badiev 《Bulletin of the Russian Academy of Sciences: Physics》2010,74(8):1138-1140
Using the Monte Carlo method, we study the critical properties of the three-dimensional frustrated Heisenberg model on a triangular
lattice with allowance for next-nearest neighbor interactions. Using the theory of finite-size scaling, we calculate the static
magnetic and chiral critical exponents of heat capacity α, susceptibility γ, γ
k
, magnetization β, β
k
, and correlation length ν. 相似文献
2.
The critical properties and phase transitions of the three-dimensional frustrated antiferromagnetic Heisenberg model on a
triangular lattice have been investigated using the Monte Carlo method with a replica algorithm. The critical temperature
has been determined and the character of the phase transitions has been analyzed using the method of fourth-order Binder cumulants.
A second-order phase transition has been found in the three-dimensional frustrated Heisenberg model on a triangular lattice.
The static magnetic and chiral critical exponents of the heat capacity α, the susceptibility γ and γ
k
, the magnetization β and β
k
, the correlation length ν and ν
k
, as well as the Fisher exponents η and η
k
, have been calculated in terms of the finite-size scaling theory. It has been demonstrated that the three-dimensional frustrated
antiferromagnetic Heisenberg model on a triangular lattice forms a new universality class of the critical behavior. 相似文献
3.
J. Ke P.-P. Li X.-S. Chen Z. Lin Y. Z. Zheng 《The European Physical Journal B - Condensed Matter and Complex Systems》2009,70(2):211-215
We propose a growing network model with link
constraint, in which new nodes are continuously introduced into
the system and immediately connected to preexisting nodes, and any
arbitrary node cannot receive new links when it reaches a maximum
number of links km. The connectivity of the network model is
then investigated by means of the rate equation approach. For the
connection kernel A(k)=kγ, the degree distribution nk
takes a power law if γ≥1 and decays stretched
exponentially if 0≤γ< 1. We also consider a network
system with the connection kernel A(k)=kα(km-k)β.
It is found that nk approaches a power law in the α> 1
case and has a stretched exponential decay in the 0≤α<
1 case, while it can take a power law with exponential truncation
in the special α=β=1 case. Moreover, nk may have a
U-type structure if α> β. 相似文献
4.
Indranil Chakrabarty Sovik Roy Nirman Ganguly Binayak S. Choudhury 《International Journal of Theoretical Physics》2009,48(6):1833-1840
In this work we describe a protocol by which two of three parties generate two bipartite entangled state among themselves
without involving third party, from a non maximal W-state or W-type state |X〉=α|001〉123+β|010〉123+γ|100〉123,α
2+β
2+γ
2=1 shared by three distant partners. Also we have considered the case β=γ, to obtain a range for α
2, for which the local output states are separable and non local output states are inseparable. We also find out the dependence
of the mixedness of inseparable states with their amount of inseparability, for that range of α
2. 相似文献
5.
I. D. Gorlachev B. B. Knyazev A. Kuketayev F. M. Pen’kov 《Bulletin of the Russian Academy of Sciences: Physics》2009,73(2):245-248
A new modification of the least squares method (LSM) is proposed. The main idea is to consider the fitting parameters β
i
as independent random variables with a certain distribution density F(β1, β2, ..., β
k
; φ1, ..., φ
m
), which depends on a set of m experimental points φ
j
. Within this approach, the estimates of the parameters minimize squared deviations and are equivalent to means of the probability distribution = = ∫β
i
F(β1, β2, ..., β
k
; φ1, ..., φ
m
)dβ1
dβ2...dβ
k
.
Original Russian Text ? I.D. Gorlachev, B.B. Knyazev, A. Kuketayev, F.M. Pen’kov, 2009, published in Izvestiya Rossiiskoi
Akademii Nauk. Seriya Fizicheskaya, 2009, Vol. 73, No. 2, pp. 257–260. 相似文献
6.
Bi4V2O11 exists in three phases viz. α, β, and γ. High temperature γ-phase can be stabilized to room temperature owing to its higher
conductivity by the partial substitution of metallic cations for vanadium in Bi4V2O11. Phase transitions from α → β and β → γ are composition and temperature-dependent. Mn2+-doped compounds Bi4V2−x
Mn
x
O11−
δ
(0 ≤ x ≤ 0.4) have been synthesized by solid state reaction technique and investigated by X-ray diffraction and ionic conductivity
measurement. High ionic conducting γ-phase is stabilized for x ≥ 0.2. The ionic conductivity of the series of Bi4V2−x
Mn
x
O11−
δ
samples has been measured by using ac impedance spectroscopy technique. The conductivity data do show departure from its
simple Arrhenius behavior for all of the compositions. The highest conductivity observed for x = 0.2 sample can be attributed to lower activation energy. 相似文献
7.
The structure of stationary isotropic, homogeneous turbulence in an incompressible fluid with Re ≫ 1 set into motion by a
force with amplitude f
0 and spatial and temporal time scales of r
0 and τ
0, respectively, is examined. It is found that, depending on the magnitude of the force that sets the fluid into motion, three
fundamentally different turbulent stationary states of the fluid can develop and the dimensionless parameters responsible
for transitions from one state to another, γ=f
0
τ
0
2
/r
0 and Γ=γ
4/3 Re, are determined. It is shown that for γ≪1 and Γ≪1 a Kolmogorov spectrum with E(k)∝1/k
5/3 develops in the inertial range. During the transition to turbulent flows driven by large amplitude forces f
0, i.e., during the transition to a regime with γ≪1 and Γ ≫ 1, a segment of the spectrum with E(k)∝1/k
2 develops near the viscous range and “detaches” the Kolmogorov spectrum from the viscous range. Further increases in the amplitude
f
0 of the force, i.e., approaching the parameter range with γ≫1 and Γ≫1, causes the entire inertial range to be “occupied” by a spectrum E(k)∝1/k
2, and outside the inertial range, large scale structures with a characteristic size extending to γ
2/5
r
0 begin to be generated. In the regime with Γ≪1, the power dissipated per unit mass of fluid is independent of the viscosity,
but on going to turbulent regimes with Γ≫1, the viscous losses begin to depend on the viscosity of the fluid. The “turn-off”
of viscous dissipation for Γ≫1 shows that a drag crisis can occur simply as the source power is increased, without any further
conditions. With this method for the excitation of turbulence, the Loitsyanskii integral diverges for arbitrary values of
γ and Γ. A physical mechanism is proposed to explain the readjustment of the spectrum of the turbulent fluctuations at different
γ and Γ. These results have all been obtained neglecting intermittency.
Zh. éksp. Teor. Fiz. 116, 1630–1647 (November 1999) 相似文献
8.
O. Perru D. Verney F. Ibrahim O. Bajeat C. Bourgeois F. Clapier E. Cottereau C. Donzaud S. Du M. Ducourtieux S. Essabaa S. Galès D. Guillemaud-Mueller O. Hubert C. Lau H. Lefort F. Le Blanc A. C. Mueller J. Obert N. Pauwels J. C. Potier F. Pougheon J. Proust B. Roussière J. Sauvage O. Sorlin 《The European Physical Journal A - Hadrons and Nuclei》2006,28(3):307-312
The γ-ray de-excitations following the β-decay of 83Ga and the β-n decay of 84Ga have been studied. The radioactive species were produced using the PARRNe on-line mass-separator installed at the IPN Orsay
Tandem accelerator. Two γ-lines were attributed to 83Ge with the aid of β-γ and γ-γ coincidences. The Z identification of the γ-lines was provided by time analysis of a buid-up/decay cycle. The excited levels of 83Ge can be explained by the coupling of the single neutron state ν2d
5/2 to the first 2+ excitation of the 82Ge core. 相似文献
9.
Y Ramakrishna K Ramachandra Rao G J Naga Raju K Bhaskara Rao V Seshagiri Rao P Venkateswarlu S Bhuloka Reddy 《Pramana》2002,59(4):685-691
The energy shifts and intensity ratios of different L X-ray components in tantalum element due to 10 MeV carbon and 12 MeV
nitrogen ions are estimated. From the observed energy shifts, the possible number of simultaneous vacancies in M shell are
estimated. A comparison of L
α
/L
β2.15, L
β1/L
γ1 and L
γ2.3/L
γ4.4 with the ratios due to Scofield theoretical transition rates indicate that the number of multiple vacancies in N shell are
higher than the vacancies in M and O shell. Employing Larkin’s statistical scaling procedure, the number of possible multiple
vacancies in N and O shells are estimated quantitatively. 相似文献
10.
Analytical expressions are derived for the components of the intrinsic frame inverse mass tensor of the Bohr Hamiltonian.
These expressions contain parameters which are determined by the experimental data on the B(E2)’s and the excitation energies of the low-lying collective states. It is shown that the nondiagonal component of the intrinsic
frame mass tensor has a small effect on the collective motion. It is shown also that the values of the B
ββ
, B
γγ
and the rotational mass coefficientB
1 differ in the well-deformed nuclei by factor 3 or more. 相似文献
11.
J. Proskurins A. Andrejevs T. Krasta J. Tambergs 《Bulletin of the Russian Academy of Sciences: Physics》2009,73(2):230-233
The classical energy functional of complete IBM-1 model version is studied in terms of nuclear shape variables (β, γ), employing
two essential control parameters (r
2, r
1) used in catastrophe theory formalism. The dependence of energy surface equilibrium values from deformation parameter β is
analyzed in the case when γ = 0. The results, obtained for critical points and phase transition lines between spherical (β
= 0) and two deformed (β > 0, β < 0) shapes, are compared with the ones, following from the studies, in which the simplified
extended Casten triangle version of interacting boson model was used.
Original Russian Text ? J. Proskurins, A. Andrejevs, T. Krasta, J. Tambergs, 2009, published in Izvestiya Rossiiskoi Akademii
Nauk. Seriya Fizicheskaya, 2009, Vol. 73, No. 2, pp. 241–244.
The article is published in the original. 相似文献
12.
V. V. Varlamov B. S. Ishkhanov V. N. Orlin S. Yu. Troshchiev 《Bulletin of the Russian Academy of Sciences: Physics》2010,74(6):842-849
The results from experimental and theoretical studies of the total and partial cross sections of photoneutron reactions on
the 197Au isotope were analyzed. The cross sections for reactions σ(γ, nX) = σ(γ, n) + σ(γ, np) + … + σ(γ, 2nX) = σ(γ, 2n) + σ(γ, 2np) + … were evaluated in the energy range 7 ≤ E
γ ≤ 30 MeV using an approach free of the shortcomings of experimental photoneutron multiplicity sorting methods. The total
photoneutron reaction cross sections σexp(γ, xn) = σexp(γ, nX) + 2σexp(γ, 2nX) + … = σexp(γ, n) + σexp(γ, np) + 2σexp(γ, 2n) + 2σexp(γ, 2np) + … were used as the initial experimental data. The contributions from the cross sections σ(γ, nX) and σ(γ, 2nX) to the cross sections σexp(γ, xn) were separated using the multiplicity transition functions F
1
theor = σtheor(γ, 1nX)/σtheor(γ, xn) and F
2
theor = σtheor(γ, 2nX)/σtheor(γ, xn), calculated within an updated version of the pre-equilibrium model of photonuclear reactions. New evaluated data for both
partial reaction cross sections, i.e., σeval (γ, 1nX) = F
1
theorσexp(γ, xn) and σeval(γ, 2nX) = F
2
theorσexp(γ, xn), were obtained. The cross sections σeval(γ, nX) and σeval.(γ, 2nX) evaluated using the theoretically calculated functions F
1,2theor are consistent with the Livermore data, but substantially contradict the Saclay data. 相似文献
13.
Gérard Ben Arous Anton Bovier Jiří Černý 《Communications in Mathematical Physics》2008,282(3):663-695
We consider a version of Glauber dynamics for a p-spin Sherrington– Kirkpatrick model of a spin glass that can be seen as a time change of simple random walk on the N-dimensional hypercube. We show that, for all p ≥ 3 and all inverse temperatures β > 0, there exists a constant γ
β ,p
> 0, such that for all exponential time scales, exp(γ N), with γ < γ
β ,p
, the properly rescaled clock process (time-change process) converges to an α-stable subordinator where α = γ/β
2 < 1. Moreover, the dynamics exhibits aging at these time scales with a time-time correlation function converging to the arcsine
law of this α-stable subordinator. In other words, up to rescaling, on these time scales (that are shorter than the equilibration time
of the system) the dynamics of p-spin models ages in the same way as the REM, and by extension Bouchaud’s REM-like trap model, confirming the latter as a
universal aging mechanism for a wide range of systems. The SK model (the case p = 2) seems to belong to a different universality class. 相似文献
14.
Some of the low-lying states in many isotopes144Nd,148Sm,152Gd and156Gd show a similar typical behaviour. The first 2+ is regarded as a single quadrupole phonon state and 3− as a single octupole phonon state. The levels with the spins and parities 1−, 5−, 3−, 4−, etc. are considered due to the simultaneous excitation of quadrupole and octupole phonons. If this consideration is correct,
then the transition fromJ
− to 2+ states must contain an appreciableE3 content. Theβ-γ-γ angular correlation coefficients for the cascade ofβ-rays ofE
max 800 keV→γ-rays of 1489 keV→γ-rays of 696 keV are used to estimateE3 content inE1 transition in144Nd. 相似文献
15.
S. E. Parkhomenko 《Journal of Experimental and Theoretical Physics》2010,111(3):375-383
The geometry of the k
K
Gepner model, where k + 2 = 2K, is investigated by a free-field representation known as the “bcβγ” system. Using this representation, we directly show that the internal sector of the model is given by Landau-Ginzburg
ℂ
K
/ℤ2K
orbifold. Then we consider the deformation of the orbifold by a marginal antichiral-chiral operator. Analyzing the chiral
de Rham complex structure in the holomorphic sector, we show that it coincides with chiral de Rham complex of some toric manifold,
where toric data are given by certain fermionic screening currents. This allows relating the Gepner model deformed by the
marginal operator to a σ-model on the CY manifold realized as a double cover of ℙ
K − 1 with ramification along a certain submanifold. 相似文献
16.
17.
M. Paasch M. Winterlich R. Böhmer R. Sonntag G. J. McIntyre A. Loidl 《Zeitschrift für Physik B Condensed Matter》1995,99(1):333-338
The χ,T phase diagram of (NH4I)x(KI)1−x has been determined using neutron diffraction experiments and dielectric spectroscopy. At low temperatures and with decreasing
χ, the sequence γ, β, ε and glass phase has been detected. The critical concentration χc≈0.55 separates the glassy phase with frozen-in orientational disorder from the ε phase which reveals long-range orientational
order. Close to χc our experiments reveal evidence for two subsequent glass transitions. 相似文献
18.
β-γ-γ directional correlation studies for the cascades (i)β-rays ofE
max=0.12 MeV,γ-rays of 557 keV andγ-rays of 53 keV and (ii)β-rays ofE
max=0.21 MeV,γ-rays of 444 keV andγ-rays of 53 keV have been made. The triple correlation functionsW(θ) were obtained to beW(θ)=1+(−0.153±0.031)P
2(cosθ)+(0.004±0.035)P
4(cosθ) forβ-rays ofE
max 0.12 MeV→557→53 keV cascade andW(θ)=1+(0.163±0.042)P
2(cosθ)+(−0.035±0.058)P
4(cosθ) forβ rays ofE
max=0.21 MeV→444 keV→53 keV cascade.
Spins and parities of the 650, 537 and 93 keV levels of103Rh are deduced by triple angular correlation and the internal conversion coefficient studies. Multipolarities of the transitions
are also determined. 相似文献
19.
Summary The differential cross-sections for the emission of Lρ, Lα, Lβ and Lγ groups of L X-ray lines from U, Th and Bi have been measured at different angles varying from 45° to 135° at intervals of
15°. The vacancies were created by 59.5 keV γ-rays from241Am source and L X-rays were measured using a Si(Li) detector. It is found that the Lγ and Lβ groups of L X-rays are isotropic, the Lρ and Lα groups are anisotropic in the spatial distribution.
The authors of this paper have agreed to not receive the proofs for correction. 相似文献
20.
Mai-hua Kuang Shan-jun Ma Dong-mei Liu 《International Journal of Theoretical Physics》2009,48(6):1790-1800
Based on the technique of integration within an ordered product of nonlinear bosonic operators, we construct a new four-mode
nonlinear entangled state |
α,β,γ〉
λ,μ
in 4-mode Fock space, which can make up a complete set. Its properties and applications are discussed. A possible scheme
to generate this state is also presented. 相似文献