Formation of p-type ZnO film on InP substrate by phosphor doping

ZnO thin film was initially deposited on InP substrate by radio frequency (rf) magnetron sputtering and the diffusion process was performed using the closed ampoule technique where Zn₃P₂ was used as the dopant source. To verify the junction formation of ZnO thin films, the electrical properties were measured, and the effects of Zn₃P₂ diffusion on ZnO thin films were investigated. It is observed that the electrical property of the film is changed from n-type to p-type by dopant diffusion effect. Based on the results, it is confirmed that ZnO thin films can be a potential candidate for ultraviolet (UV) optical devices.     

B → πlΝ form factors calculated on the light-front

A consistent treatment of B → πlν decay is given on the light-front. The B to π transition form factors are calculated in the entire physical range of momentum transfer for the first time. The valence-quark contribution is obtained using relativistic light-front wave functions. Higher quark-antiquark Fock-state of the B-meson bound state is represented effectively by the ¦B*π〉 configuration, and its effect is calculated in the chiral perturbation theory. Wave function renormalization is taken into account consistently. The ¦B*π〉 contribution dominates near the zero-recoil point (q ² ? 25 GeV²), and decreases rapidly as the recoil momentum increases. The calculated form factor ?+(q ²) follows approximately a dipole q ²-dependence in the entire range of momentum transfer. We estimate that ¦V _ub¦=0.003.     

Search for chiral bands in A ～ 110 neutron-rich nuclei

High spin states in A ～ 110 neutron-rich 106Mo, 110Ru and 112Ru nuclei have been reinvestigated by measuring the prompt γ-rays from the spontaneous fission of 252Cf. Two similar sets of bands are observed to high spins in each of three nuclei. Through analyzing of characters of the band structures, the chiral doublet bands are suggested in 106Mo, 110Ru and 112Ru.     

Effective potential for highly relativistic neutrinos in a weakly magnetized medium and their oscillation

We have calculated the effective potential experienced by highly relativistic neutrinos in a weakly magnetized electron–positron plasma, where a momentum-dependent finite-width correction to the propagator of W is considered to account for the threshold effect. Magnetars are believed to be sources of TeV–PeV neutrinos which are produced due to photomeson and proton–proton interactions in their atmosphere. We have studied the resonant-oscillation process ν _e ↔ ν _μ,τ of the highly relativistic neutrinos in the atmosphere of SGR 1806-20, which is a magnetar. It is shown that, for high-energy neutrinos propagating within the magnetar atmosphere, the resonance condition can never be satisfied. On the other hand, if GeV neutrinos are produced deep inside the magnetar atmosphere, where the temperature is about 50 keV or more, then these neutrinos can undergo resonant oscillation.     

Depth-controlled reconstruction of 3D integral image using synthesized intermediate sub-images

In this paper, we propose a method that controls the depth of the three-dimensional (3D) object existing over the depth-of-focus in integral imaging. The depth control method is performed only in a computer by synthesizing the intermediate sub-images between original sub-images obtained by transforming the captured elemental images. In the reconstruction process, we can obtain reconstructed 3D images with the better image quality within depth-of-focus than that reconstructed over the depth-of-focus. To demonstrate the feasibility of our method, optical and computational experiments are carried out and its results are presented.     

Numerical visualization of vortical structures in a lean premixed swirl combustor using LES

Abstract  

Large eddy simulation was performed to visualize the three-dimensional vortical structures interacting with a turbulent premixed in a lean premixed swirl combustor with varied equivalence ratio. It was found that the fluctuation of unsteady heat release due to the deformation of flame surface was significantly decreased as the equivalence ratio increased because of the change in interaction between inner vortical structures and flames. This phenomenon was another evidence of the amplification mechanism in the combustion instabilities due to the strong flame–vortex interactions under lean premixed conditions.     

An Efficient Quantum Private Comparison of Equality over Collective-Noise Channels

This article proposes a collective-noise resistant QPC protocol with the help of an almostdishonest third party (TP) who may try to perform any sort of attacks to derive participants’ private secrets except colluding with any participant. The proposed scheme has some considerable advantages over the state-of-the-art QPC protocols over collective-noise channels, where it does not require any pre-shared key between the participants (Alice and Bob). Nevertheless, the proposed scheme can resist Trojan horse attacks without consuming half of the transmitted qubits and any additional equipment (wavelength filter and PNS) support. As a consequence, the proposed QPC protocol can guarantee higher qubit efficiency as compared to the others over collective noise channels.     

Laboratory vacuum spectrometer for the soft x‐ray region

A laboratory surface x‐ray absorption near edge structure ((S)XANES) spectrometer used for measurements in the soft x‐ray region is described. The x‐ray beam path of the spectrometer is enclosed in a vacuum chamber directly connected to the x‐ray generator output port. With this setup, the absorption of the x‐rays in the air is avoided. The developed spectrometer uses a monochromator equipped with cylindrically bent PET(002), KAP(001), and Ge(111) crystals of different Rowland radii working in the Johann focusing geometry. Nine stepping motors are used to control the positions of the monochromator, receiving slit, sample, and detectors. An x‐ray photon energy available in experiment ranges from about 1 keV to 5 keV. A registration of the photoelectrons emitted from the sample with the channeltron is used to carry out surface‐sensitive measurements. The performance of the developed spectrometer is illustrated by spectra measured at the absorption K‐edges of several elements from the Na‐Ti set. Copyright © 2008 John Wiley & Sons, Ltd.     

Partition function zeros of the antiferromagnetic Ising model on triangular lattice in the complex temperature plane for nonzero magnetic field

The grand partition functions Z(T,B)$Z(T,B)$ of the Ising model on L×L$L\times L$ triangular lattices with fully periodic boundary conditions, as a function of temperature T and magnetic field B  , are evaluated exactly for L<12$L<12$ (using microcanonical transfer matrix) and approximately for L?12$L?12$ (using Wang–Landau Monte Carlo algorithm). From Z(T,B)$Z(T,B)$, the distributions of the partition function zeros of the triangular-lattice Ising model in the complex temperature plane for real B≠0$B\ne 0$ are obtained and discussed for the first time. The critical points aN(x)$a_N(x)$ and the thermal scaling exponents yt(x)$y_t(x)$ of the triangular-lattice Ising antiferromagnet, for various values of x=e−2βB$x=e^{-2\beta B}$, are estimated using the partition function zeros.     

Feasibility of probing boundary morphology of structured materials by 2D NMR q-space imaging

It is well known that one-dimensional (1D) q-space imaging allows retrieval of structural information at cellular resolution. Here we demonstrate by simulation that boundary morphology of structured materials can be derived from 2D q-space mapping. Based on a finite-difference model for restricted diffusion, 2D q-space maps obtained from water diffusion inside apertures at various levels of asperity were simulated. The results indicate that the observed ring patterns (diffraction minima) reveal the boundary profiles of the apertures but become blurred in the case of significant variation in aperture size. For uniform size distribution of apertures, a quantitative measure of surface roughness can be established by means of spatial autocorrelation analysis. The results suggest that 2D q-space imaging may allow probing of the boundary morphology of structured materials and possibly biological cells.