共查询到20条相似文献,搜索用时 31 毫秒
1.
D. Yu. Kouznetsov 《Moscow University Physics Bulletin》2010,65(2):91-98
The logistic problem is formulated in terms of the Superfunction and Abelfunction of the quadratic transfer function H(z) = uz(1 − z). The Superfunction F as holomorphic solution of equation H(F(z)) = F(z + 1) generalizes the logistic sequence to the complex values of the argument z. The efficient algorithm for the evaluation of function F and its inverse function, id est, the Abelfunction G are suggested; F(G(z)) = z. The halfiteration h(z) = F(1/2 + G(z)) is constructed; in wide range of values z, the relation h(h(z)) = H(z) holds. For the special case u = 4, the Superfunction F and the Abelfunction G are expressed in terms of elementary functions. 相似文献
2.
V. E. Tarasov V. V. Khabarov A. E. Kudryavtsev V. M. Weinberg 《Physics of Atomic Nuclei》2008,71(8):1410-1423
The Kd reactions are considered in the impulse approximationwithNN final-state interactions (FSI) taken into account. Realistic parameters for the KN phase shifts are used. The “quasi-elastic” energy region, in which the elementary KN interaction is predominantly elastic, is considered. The theoretical predictions are compared with the data on the K
+
d → K
+
pn, K
+
d → K0
pp, K
+
d → K
+
d, and K
+
d total cross sections. The NN FSI effect in the reaction K
+
d → K
+
pn has been found to be large. The predictions for the Kd cross sections are also given for slow kaons, produced from ϕ(1020) decays, as the functions of the isoscalar KN scattering length a
0. These predictions can be used to extract the value of a
0 from the data.
The text was submitted by the authors in English. 相似文献
3.
The diffusion of carbon atoms between the volume and the surface of (100) molybdenum is directly studied at temperatures between 1400 and 2000 K (i.e., at process temperatures) for the first time. The balance of carbon atoms in the system is determined. The difference in the activation energies of carbon dissolution and precipitation, ΔE=E s 1-E1s, is found for the case when the diffusion fluxes of dissolved and precipitated carbon atoms are in equilibrium. This difference defines the enrichment of the surface by carbon relative to the bulk. The experimentally found activation energy of carbon dissolution is Es1=3.9 eV. The activation energy of carbon precipitation is estimated at E 1 s=1.9 eV. The latter value is close to the energy of bulk diffusion of carbon in molybdenum. 相似文献
4.
Carl M. Bender 《Czechoslovak Journal of Physics》2004,54(1):13-28
The Hamiltonian H specifies the energy levels and the time evolution of a quantum theory. It is an axiom of quantum mechanics that H be Hermitian. The Hermiticity of H guarantees that the energy spectrum is real and that the time evolution is unitary (probability preserving). In this talk we investigate an alternative formulation of quantum mechanics in which the mathematical requirement of Hermiticity is replaced by the more physically transparent condition of space-time reflection (PT) symmetry. We show that if the PT symmetry of a Hamiltonian H is not broken, then the spectrum of H is real. Examples of PT-symmetric non-Hermitian Hamiltonians are H=p
2+ix
3 and H=p
2-x
4. The crucial question is whether PT-symmetric Hamiltonians specify physically acceptable quantum theories in which the norms of states are positive and the time evolution is unitary. The answer is that a Hamiltonian that has an unbroken PT symmetry also possesses a physical symmetry that we call C. Using C, we show how to construct an inner product whose associated norm is positive definite. The result is a new class of fully consistent complex quantum theories. Observables exhibit CPT symmetry, probabilities are positive, and the dynamics is governed by unitary time evolution. 相似文献
5.
The general properties of the factorized S-matrix in two-dimensional space-time are considered. The relation between the factorization property of the scattering theory and the infinite number of conservation laws of the underlying field theory is discussed. The factorization of the total S-matrix is shown to impose hard restrictions on two-particle matrix elements: they should satisfy special identities, the so-called factorization equations. The general solution of the unitarity, crossing and factorization equations is found for the S-matrices having isotopic O(N)-symmetry. The solution turns out to have different properties for the cases N = 2 and N 3. For N = 2 the general solution depends on one parameter (of coupling constant type), whereas the solution for N 3 has no parameters but depends analytically on N. The solution for N = 2 is shown to be an exact soliton S-matrix of the sine-Gordon model (equivalently the massive Thirring model). The total S-matrix of the model is constructed. In the case of N 3 there are two “minimum” solutions, i.e., those having a minimum set of singularities. One of them is shown to be an exact S matrix of the quantum O(N)-symmetric nonlinear σ-model, the other is argued to describe the scattering of elementary particles of the Gross-Neveu model. 相似文献
6.
Raziye Ertuğrul 《辐射效应与固体损伤》2013,168(9):791-799
The effects of gamma irradiation on electrical parameters of Au/Si3N4/n-Si (MIS) structure were investigated by using the capacitance–voltage (C–V) and conductance–voltage (G/ω–V) measurements. The MIS structure was irradiated using gamma-radiation source at a dose rate of 0.69?kGy/h. The C–V and G/ω–V measurements were carried out at a total dose range of 0–100?kGy for five different frequencies (1, 10, 100, 500 and 1000?kHz). The obtained results showed that the C and G/ω values decrease with the increasing radiation dose due to the irradiation-induced defects at the interface. Also, the observed decrease in the C and G/ω values with the increasing frequency was explained on the basis of interface states (Nss). The values of series resistance (Rs) increase with the increasing radiation dose. To obtain the real capacitance and conductance of the capacitor, the measured values of C and G/ω were corrected to eliminate the effect of series resistance. The values of Nss were determined by using the conductance method and were decreased with the increasing radiation dose. 相似文献
7.
8.
Masataka Hakamada Fumi Hirashima Kota Kajikawa Mamoru Mabuchi 《Applied Physics A: Materials Science & Processing》2012,106(1):237-244
The magnetic moments of the fcc/fcc, hcp/hcp twin and fcc/hcp twin-like boundaries in cobalt were investigated by first-principles calculations based on density functional theory. The
magnetic moments in fcc/fcc were larger than those of the bulk fcc, while the variations in the magnetic moment were complicated in hcp/hcp and fcc/hcp. The magnetovolume effect on the magnetic moment at the twin(-like) boundaries was investigated in terms of the local average
atomic distance and the average deviation from equilibrium; however, the complicated variations in the magnetic moment could
not be explained from the magnetovolume effect. Next, the narrowing (or broadening) of the partial density of states (PDOS)
width of 3d orbitals, the number of occupied states for the spin-down channel, and the PDOS around the Fermi level were investigated.
The entire variation in the magnetic moment at the twin(-like) boundaries could be understood in terms of these factors. Charge
transfer occurred in hcp/hcp. In this case, the contributions of 4s and 4p electrons to the variation in the magnetic moment were relatively large. 相似文献
9.
The density, ρ, of N-(p-n-octyloxy benzylidene) p-n-butyl aniline (OBBA) is measured as a function of temperature from the isotropic liquid to the smectic-G phase. The compound is trimorphic, exhibiting three smectic phases, smectic-G, crystal smectic-B, and smectic-A phase. The changes in density across the phase transformations and the calculated thermal expansion coefficients confirm the order of the transitions as first order. Particular importance of the smectic-A to crystal smectic-B transformation, which is of first order, is apparent from the density jump across the transition. 相似文献
10.
G. Pratesi A. Bellosi F. Barocchi 《The European Physical Journal B - Condensed Matter and Complex Systems》2000,18(2):283-287
The pressure and temperature dependences of the depolarized light scattering spectra of salol have been measured at isobaric
condition P = 1 bar for T between 328 and 393 K, and at isothermal condition T = 343 K for P between 1 and 625 bar, i.e. outside the metastable liquid region. The experimental results for both the α- and β-relaxations can be well described by
the Mode Coupling Theory. The independence of the power-law parameters a, and consequently b and γ, from the thermodynamic variables T and P is demonstrated.The critical temperature T
c at 1 bar and the critical pressure P
c at T = 343 K have been determined from the normal liquid state.
Received 2 May 2000 相似文献
11.
The properties of the superconducting state in the amorphous Sn1?xCux thin films were characterized. The concentration of copper changes in the range from 0.08 to 0.41. The calculations were conducted in the framework of the strong-coupling formalism, wherein the Eliashberg functions determined in the tunnel experiment were used. The value of the Coulomb pseudopotential equal to 0.1 was adopted. It will be shown that the critical temperature (TC) decreases from 7 to 3.9 K. The ratio, RΔ = 2Δ(0)/kBTC, differs from the BCS value: RΔ ∈ <4.4, 3.95>, where Δ(0) represents the order parameter. Similarly behave the ratios: RC = ΔC(TC)/CN(TC) ∈ <2.2, 1.75> and RH = TCCN(TC)/H2C(0) ∈ <0.141, 0.154>. The parameter ΔC(TC) is the specific heat jump, CN(TC) denotes the specific heat of the normal state and HC(0) is the thermodynamic critical field. 相似文献
12.
Eunghyun Lee 《Journal of statistical physics》2012,149(1):50-72
In this paper we treat the multiparticle hopping asymmetric diffusion model (MADM) on ℤ introduced by Sasamoto and Wadati in 1998. The transition probability of the MADM with N particles is provided by using the Bethe ansatz. The transition probability is expressed as the sum of N-dimensional contour integrals of which contours are circles centered at the origin with restrictions on their radii. By using the transition probability we find ℙ(x m (t)=x), the probability that the mth particle from the left is at x at time t. The probability ℙ(x m (t)=x) is expressed as the sum of |S|-dimensional contour integrals over all S⊂{1,…,N} with |S|≥m, and is used to give the current distribution of the system. The mapping between the MADM and the pushing asymmetric simple exclusion process (PushASEP) is discussed. 相似文献
13.
A specific quantum Lax operator, forming a quantum U
q
(sl
n) chain, is suggested. The intertwining R
L
L relation is proved. The invariant local 2+1-dimensional reformulation of the auxiliary linear problem for the L-operator is discussed. 相似文献
14.
The total cross-sections for the photo-nucleon reactions y + p → p + v + v? and y + n → n + v + v? are calculated according to Weinberg-Salam theory. The effect of the form factors is taken in the electromagnetic vertex. The dependence of the total cross-sections on the energy of the incident photon is explicitly shown. 相似文献
15.
Y. Ōno R. Bulla A.C. Hewson 《The European Physical Journal B - Condensed Matter and Complex Systems》2001,19(3):375-384
The Mott metal-insulator transition in the two-band Hubbard model in infinite dimensions is studied by using the linearized
dynamical mean-field theory recently developed by Bulla and Potthoff. The phase boundary of the metal-insulator transition
is obtained analytically as a function of the on-site Coulomb interaction at the d-orbital, the charge-transfer energy between the d- and p-orbitals and the hopping integrals between p-d, d-d and p-p orbitals. The result is in good agreement with the numerical results obtained from the exact diagonalization method.
Received 5 October 2000 and Received in final form 8 December 2000 相似文献
16.
The effects of final-state interactions (FSI) in hadronic B decays are investigated. The model for FSI, based on Regge phenomenology of high-energy hadronic interactions, is proposed.
It is shown that this model explains the pattern of phases in matrix elements of B → ππ and B → ρρ decays. These phases play an important role for CP violation in B decays. The most precise determination of the unitarity triangle angle α from B
d
→ ρπ decays is performed. The relation between CP asymmetries in B → Kπ decays is discussed. It is emphasized that the large-distance FSI can explain the structure of polarizations of the vector
mesons in B decays and other puzzles like a very large branching ratio of the B decay to $
\bar \Xi
$
\bar \Xi
c
Λ
c
. 相似文献
17.
Roberto Zucchini 《Communications in Mathematical Physics》1996,181(3):529-568
A lagrangian euclidean model of Drinfeld-Sokolov (DS) reduction leading to generalW-algebras on a Riemann surface of any genus is presented. The background geometry is given by the DS principal bundleK associated to a complex Lie groupG and anSL(2,) subgroupS. The basic fields are a hermitian fiber metricH ofK and a (0, 1) Koszul gauge fieldA
* ofK valued in a certain negative graded subalgebrar ofg related tos. The action governing theH andA
* dynamics is the effective action of a DS field theory in the geometric background specified byH andA
*. Quantization ofH andA
* implements on one hand the DS reduction and on the other defines a novel model of 2d gravity, DS gravity. The gauge fixing of the DS gauge symmetry yields an integration on a moduli space of DS gauge equivalence classes ofA
* configurations, the DS moduli space. The model has a residual gauge symmetry associated to the DS gauge transformations leaving a given fieldA
* invariant. This is the DS counterpart of conformal symmetry. Conformal invariance and certain non-perturbative features of the model are discussed in detail. 相似文献
18.
The annihilation of slow (∼7 MeV) antiprotons in nuclear emulsion has been studied. The yields and energy spectra of p, d, t, and α particles in the evaporation region have been measured. The shape of the spectra of p, d, and t is in agreement with the Maxwell distribution and the excitation energy of a nucleus is consistent with a theoretical estimate
for evaporation from the equilibrium state. The probability of the absorption of antiprotons inside the nucleus estimated
from the multiplicity of h particles is ɛ = (2.0 ± 0.6) × 10−2. The relative d/p yield coincides with a similar ratio appearing in the capture of slow π− mesons by nuclei in the nuclear emulsion. The yields of t and α particles in the process of the annihilation of antiprotons are much higher than those in a similar process for pions.
To identify g particles (0.29 < β < 0.70), energy losses dE/dx on ionization and multiple scattering have been measured. In this velocity region, the yields of p, d, t, and pions have been observed. The ratios (n
d
/n
p
)
g
, (n
d
/n
p
)
b
, and n
d
/n
p
measured in the capture of π− mesons are almost the same. In this velocity range (g particles), α particles have not been observed. 相似文献
19.
G.I. Japaridze S. Sarkar 《The European Physical Journal B - Condensed Matter and Complex Systems》2002,28(2):139-144
A one-dimensional model of interacting electrons with on-site U, nearest-neighbor V, and pair-hopping interaction W is studied at half-filling using the continuum limit field theory approach. The ground state phase diagram is obtained for
a wide range of coupling constants. In addition to the insulating spin-density wave (SDW) and charge-density wave (CDW) phases
for large U and V, respectively, we identify a bond-charge-density-wave (BCDW) phase W < 0, | U - 2V| < | 2W| and a bond-spin-density-wave (BSDW) for W > 0, | U - 2V| < W. The possibility of bond-located ordering results from the site-off-diagonal nature of the pair-hopping term and is a special
feature of the half-filled band case. The BCDW phase corresponding to an enhanced Peierls instability in the system. The BdSDW
is an unconventional insulating magnetic phase, characterized by a gapless spin excitation spectrum and a staggered magnetization
located on bonds between sites. The general ground state phase diagram including insulating, metallic, and superconducting
phases is discussed. A transition to the η-superconducting phase at | U - 2V| ≪ 2t?W is briefly discussed.
Received 20 February 2002 / Received in final form 11 April 2002 Published online 19 July 2002 相似文献
20.
With the decay constants of D and D
s
mesons measured in experiment recently, we revisit the study of the bound states of quark and antiquark in B and D mesons in the relativistic potential model. The relativistic bound state wave equation is solved numerically. The masses,
decay constants and wave functions of B and D mesons are obtained. Both the masses and decay constants obtained here can be seen as consistent with the experimental data.
The wave functions can be used in the study of B and D meson decays. 相似文献