h-Deformation of GL(1∣1)

An h-deformation of a (graded) Hopf algebra of functions on supergroup GL(11) is introduced via a contraction of GL _q (11). The deformation parameter h is odd (Grassmann). A related differential calculus on h-superplane is presented.     

Solution of functional equations of restricted An−1(1) fused lattice models

Functional equations, in the form of fusion hierarchies, are studied for the transfer matrices of the fused restricted A_n−1⁽¹⁾ lattice models of Jimbo, Miwa and Okado. Specifically, these equations are solved analytically for the finite-size scaling spectra, central charges and some conformal weights. The results are obtained in terms of Rogers dilogarithm and correspond to coset conformal field theories based on the affine Lie algebra A_n−1⁽¹⁾ with GKO pair A_n−1⁽¹⁾ ⊕ A_n−1⁽¹⁾ ⊃ A_n−1⁽¹⁾.     

On the hopf structure of U p,q (gl(1∣1)) and the universal T-matrix of fun p,q (GL(1∣1))

The dually conjugate Hopf superalgebras Fun _p,q (GL(11)) and U _p,q (gl(11)) are studied using the Frønsdal-Galindo approach and the full Hopf structure of U _p,q (gl(11)) is extracted. A finite expression for the universal T-matrix, identified with the dual form and expressing the generalization of the exponential map of the classical groups, is obtained for Fun _p,q (GL(11)). In a representation with a colour index, the T-matrix assumes a form that satisfies a coloured graded Yang-Baxter equation.     

He diffraction study of the OH(1×1)−Ag(110) phase

Summary The OH(1×1)−Ag(110) phase obtained after H₂O dissociation on the O(2×1)−Ag(110) surface is investigated. Structural and electronic properties are studied by He diffractive scattering and angularly resolved ultraviolet photoemission spectroscopy (ARUPS). Diffractive data are interpreted in terms of the hard corrugated wall (HCW) potential leading to the determination of the corrugation function ζ(R). The shape of ζ(R) indicates that the phase under study is formed of OH rows along where hydroxil groups interact strongly. The interaction between rows instead is weak and essentially republsive. In honour of Prof. Fausto Fumi on the occasion of his retirement from teaching.     

The high-resolution spectrum of the ν1 (A1) band of 12CD3F

The spectrum of the ν₁ (A₁) band of ¹²CD₃F has been recorded with a resolution of 0.010 cm⁻¹ and deconvolved to 0.005 cm⁻¹. Over 1050 transitions have been assigned with K ≤ 16 and J ≤ 42. The spectrum is highly perturbed, exhibiting avoided crossings in most of the observed sub-bands. The origin of most of the local and global resonances has been determined and the coupling constants estimated. Due to the complexity of the spectrum resulting from the 24 potential interacting states in the region, the assigned frequencies were fitted in a restricted manner (K ≤ 3, J ≤ 15), to obtain the following effective constants for the band: ν₀ = 2090.8118(20) cm⁻¹, α^A = 1.19743 × 10⁻² cm⁻¹, and α^B = −1.8489 × 10⁻³ cm⁻¹. From an unrestricted least-squares analysis, fixing the above parameters the β's (D_v^x = D₀^x − β_v^x) were calculated to be β^J = 1.7776 × 10⁻⁷ cm⁻¹, β^JK = 8.3406 × 10⁻⁷ cm⁻¹, and β^K = −6.3829 × 10⁻⁷ cm⁻¹. These constants serve as good starting parameters for the global analysis necessary to fully analyze the 5-μm region of the ¹²CD₃F spectrum.     

Numerical study of anomalous dynamic scaling behaviour of (1+1)-dimensional Das Sarma-Tamborenea model

In order to discuss the finite-size effect and the anomalous dynamic scaling behaviour of Das Sarma-Tamborenea growth model,the (1+1)-dimensional Das Sarma-Tamborenea model is simulated on a large length scale by using the kinetic Monte-Carlo method.In the simulation,noise reduction technique is used in order to eliminate the crossover effect.Our results show that due to the existence of the finite-size effect,the effective global roughness exponent of the (1+1)-dimensional Das Sarma-Tamborenea model systematically decreases with system size L increasing when L > 256.This finding proves the conjecture by Aarao Reis[Aarao Reis F D A 2004 Phys.Rev.E 70 031607].In addition,our simulation results also show that the Das Sarma-Tamborenea model in 1+1 dimensions indeed exhibits intrinsic anomalous scaling behaviour.     

Structure of σ model in [1, 1] representation of SU(2) ⊗ SU(2) group

The spontaneous breakdown of symmetry of the-model in the [1, 1] representation of SU(2) SU(2) group is investigated. It is shown that the spontaneous breakdown is realized in all cases of squared mass ² in mass term in the Lagrangian ( ²>0, ²=0, ²<0), unlike the-model in [1/2, 1/2] representation, in which the spontaneous breakdown only for the case ²<0 manifests itself. Further, different but equivalent methods of obtaining the nonlinear realization for pions in the frame of an extended in such a way-model are demonstrated. Finally, it is sketched, that the obtained results can be generalized to all [N/2,N/2] representations of SU(2) SU(2) chiral group.Presented at the Symposium on Hadron-Hadron Scattering at High Energies, Liblice, Czechoslovakia, June 16–21, 1975.On leave of absence from theDept. of Theoretical Physics, Comenius University, Bratislava, Czechoslovakia.     

On the Reasons of Assymetricity of the Shape of Contour of Vibrational Line ν1(A 1) in Raman Spectra of LiNO3 Melt

Optics and Spectroscopy - The reasons leading to the asymmetry of the shape of the ν1(А1) contour of the nitrate ion in the spectra of lithium nitrate melts were analyzed. It was shown...     

Feature extraction of ship radiated-noise by 1(1/2)-spectrum

1 lntroductionIn ship radiated-noise, there are a series of line spectra and co11til1uous spectra cre-ated b}' vortex flow, turbulence, sparge, impulsion and random vibration. The fOrmersare useful fOr classification alld recognition of ships. But fOr the later. the used infOrmation is only several points located at the outIine of continuous spectrum instead of thedetail xuriety of it. The points represent the \urying trend or shape character. Becausethe continuous spectra are related to lin…     

How atoms move in the (1 × 1) to (1 × 2) surface reconstruction of fcc (110) planes

The result of a recent study of atomic steps in the (1 × 1) to (1 × 2) surface reconstruction of Pt and Ir (110) planes using ns pulsed-laser heating can only be understood by highly correlated jumps of atoms within a small [110] atom-row. We argue in favor of a simultaneous jump of the entire small [110] row of atoms, possibly stimulated by surface phonon waves propagating in the direction normal to, and also parallel to, the atom-row direction. Surface reconstruction of fcc (110) planes evolves with long-range atomic diffusion, thus the transition occurs relatively slowly. Reconstruction of fcc (001) planes evolves with short-range atomic movements, and the transition occurs very rapidly.     

Ab initio investigation of tensile strengths of metal(1 1 1)/α-Al2O3(0 0 0 1) interfaces

Ab initio calculations using plane wave pseudopotential method within density funtional theory are applied to investigate mechanical and electronic properties of Al-terminated Me(1 1 1)/Al₂O₃(0 0 0 1) (Me = Al, Ag, Cu, Nb) interfaces. Stress–displacement relationships of separation perpendicular to the interface are calculated. It is shown that obtained results such as work of separation and tensile strength can be understood from electronic structure.     

Fabrication of aluminum nitride heterostructures on Si (1 1 1) substrate by plasma-assisted MBE

The aluminum nitride (AlN) heterostructures were successfully grown on silicon substrate by plasma-assisted molecular beam epitaxy. The surface morphology and structural and optical properties of the sample have been investigated by reflection high electron diffraction, scanning electron microscopy, field emission scanning electron microscopy (FESEM), energy dispersive X-ray, high-resolution X-ray diffraction (HR-XRD), Raman spectroscopy, and photoluminescence, respectively. HR-XRD measurement showed that the sample has a typical diffraction pattern of hexagonal AlN/GaN/AlN heterostructures. The Schottky characteristic of Pt contact on AlN/GaN/AlN heterostructures was also investigated under different annealing temperatures in nitrogen ambient. The temperature dependence and structural evolution of the Schottky barrier height (SBH) of Pt contacts were studied using the current–voltage measurement and FESEM, respectively. Our findings presented that the SBH of the samples change with different annealing temperatures.     

Ab initio CI study of the vibrational structure of the 1 1Σ− (1 1 A″)←X and 1 1Δ (2 1 A′, 2 1 A″)←X electronic transitions in HCN and DCN

The results of an ab initio CI study of the vibrational/vibronic structure of the 1 ¹Σ^? (1 ¹ A″)←X and 1 ¹Δ (2 ¹ A′, 2 ¹ A″)←X electronic transitions in HCN and DCN are presented. Calculated band positions and intensity distributions within the band progressions are compared with corresponding experimental data. While the theoretical results for the 1A″←X transition reproduce well the structure of the observed A-X spectrum, they place doubt on the Bickel-Innes interpretation of the B-X band system in terms of transitions to the same excited electronic state but accompanied by excitation of a single quantum of the C?H stretching vibrational mode.     

Oxidation of Si(100)2x1 and Gex Si1−x (100)2x1

High resolution electron energy loss Spectroscopy (HREELS), X-ray photoelectron Spectroscopy (XPS) and low energy electron diffraction (LEED) have been used to characterize initial stages of oxidation of Si(100)2x1 and Ge_x Si_1−x (100)2x1 surfaces. Different oxidation stages of Si were identified by measuring Si 2p core level shifts and characteristic vibrations of Si-O-Si complexes. The latter may be described in the framework of continuous random network models.Then,from the experimentally determined frequencies, force constants,average bond angles and bond lengths are determined. Complementary,marker experiments with atomic hydrogen as a probe in conjunction with HREELS were used to determine the local, atomic structure for different stages of oxidation from chemical shifts of Si-H and Ge-H stretching mode intensities, respectively.     

Interaction of two two-level atoms with SU (1, 1 ) coherent states

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Optical transitions on (1 1 0) surfaces of III–V compounds

The modulation reflectivity technique was used to detect the optical transition on clean cleaved (1 1 0) surfaces of III–V compounds. In the spectra obtained the optical transitions involving surface eigenstates were identified.     

Superconductivity of (Sn1−z Pbz)1−x InxTe alloys

The temperature dependences of the electrical resistivity of (Sn_1?z Pb_z)_1?x In_xTe alloys with different concentrations of lead (z=0–0.60) and indium (x=0.03–0.20) were studied at temperatures T=0.4–4.2 K in magnetic fields from zero to H=15 kOe. A resistivity drop of no less than three-four orders of magnitude was observed in this range of alloy compositions. Application of a magnetic field above a critical level resulted in a recovery of the sample resistivity to the original value. The observed resistivity drop is identified with a superconducting transition. The critical parameters of the superconducting transition (T _c and H _c2) were determined at the drop to one half the normal resistivity level. Experimental dependences of the critical supercon-ducting-transition temperature T _c and of the second critical magnetic field H _c2 on the contents of lead (z) and indium (x) were measured. The data obtained confirm a strong localization of the In impurity states and are evidence of the extrinsic nature of superconductivity in the class of materials under study. It was established that as the Pb content in (Sn_1?z Pb_z)_1?x In_xTe increases, T _c and H _c2 decrease as the Fermi level E _F (fixed in the In impurity resonance band) leaves the Δ extremum and the superconductivity breaks down when E _F leaves the LΣ saddle point in the valence-band energy spectrum.     

Study of the decayf 1(1285)→ρ0(770)γ

The decayf ₁(1285)→ρ⁰(770)γ was studied at VES spectrometer of IHEP. Clear signal off ₁(1285) is seen in the effective mass spectrum of the π⁺π^?γ system in the reaction π^?γN→π⁺π^?π^?γN at the momentum $P_{\pi ^ - } = 37 GeV/c$ . The branching fraction of decayf ₁(1285)→ρ⁰(770)γ has been found to be $$BR(f_1 (1285) \to \rho ^0 (770)\gamma ) = (2.8 \pm 0.7(stat) \pm 0.6(syst)) \cdot 10^{ - 2} .$$ The ratio of the helicity amplitudes for ρ⁰ meson in its rest frame was determined by the analysis of angular distributions: $$\rho _{00} /\rho _{11} = 3.9 \pm 0.9(stat) \pm 1.0(syst).$$