A perfect multi-hop teleportation scheme for transfer of five-qubit entangled states using intermediate nodes

In this paper, we consider a multi-hop teleportation protocol for transfer of certain five-qubit entangled states. The speciality of this protocol is that intermediate nodes between the sender and the receiver are introduced. Teleportation processes over long distances are problematic because of the existence of the environmental noise which is almost unavoidable and adversely affects the entangled quantum channel. With a view to the above, intermediate nodes are introduced which are connected in series by entanglement. These short range quantum channels minimize the risk of the protocol being affected by noise. The present protocol is performed in an integrated manner in which the parties in the intermediate nodes act independently. A remarkable feature of the protocol is that only 3.13% of the basis elements are involved in the measurements. We also calculate the efficiency and indicate the advantages of the present protocol. The work is in the direction of research for transferring entangled quantum states.     

A scheme for a conditional quantum phase gate using a bimodal cavity and a ladder-type three-level atom

A scheme is proposed to implement a two-qubit conditional quantum phase gate for the intracavity field using a single ladder-type three-level atom driven by two modes in a high-Q cavity. The quantum information is encoded on the Fock states of a bimodal cavity. The averaged fidelity of the gate can be expected to reach 99.86%.     

A simple demonstration of the Pancharatnam phase as a geometric phase

Abstract

To demonstrate the Pancharatnam phase as a geometric (Berry's) phase, each polarization state must be obtained by projecting the previous state on it. We describe a simple interferometric arrangement for such a demonstration which only uses a single rotation linear analyser to introduce a continuously variable phase difference between the two beams.     

A simple scheme for self-focusing of an array

A self-focusing technique and its application to a linear array system are presented in this paper. By application of the technique the system is capable of both sonification and reception focusing. The array is first excited as an unfocused array. Next a cross-correlation technique is used to determine time delays of reception of the largest amplitude backscattered signals at the elements of the array. The original transducer signal is then reemitted with the appropriate time delays to achieve sonification focusing on the scatterer producing the largest signal. This process is repeated in an iterative mode to focus energy on the strongest scatterer. Once insonification focusing has been achieved the last time-delay calculations are used once more for reception focusing, i.e., to correct the signals received by the individual elements for differences in arrival times. A low cost linear array has been constructed to implement the self-focusing technique. Examples demonstrate the capability of the technique to focus on the largest hole of sets of three holes in an aluminum specimen.     

A coupled numerical scheme of dual reciprocity BEM with DQM for the transient elastodynamic problems

The two‐dimensional transient elastodynamic problems are solved numerically by using the coupling of the dual reciprocity boundary element method (DRBEM) in spatial domain with the differential quadrature method (DQM) in time domain. The DRBEM with the fundamental solution of the Laplace equation transforms the domain integrals into the boundary integrals that contain the first‐ and the second‐order time derivative terms. Thus, the application of DRBEM to elastodynamic problems results in a system of second‐order ordinary differential equations in time. This system is then discretized by the polynomial‐based DQM with respect to time, which gives a system of linear algebraic equations after the imposition of both the boundary and the initial conditions. Therefore, the solution is obtained at any required time level at one stroke without the use of an iterative scheme and without the need of very small step size in time direction. The numerical results are visualized in terms of graphics. Copyright © 2008 John Wiley & Sons, Ltd.     

A simple semi sol-gel method for preparation of alumina monoliths with hierarchical pore structures

A simple semi sol-gel method for preparation of stable alumina monoliths is presented. The approach is based on chemical binding of boehmite by hydrolysis products of aluminium nitrate. The crystalline phase of the monoliths depends on the calcination temperature, and the size and shape of the alumina crystallites were determined by transmission electron microscopy and modelling of X-ray diffraction patterns. The monoliths have bimodal pore size distributions with mesopores ranging from 3 to 20 nm and macropores ranging from 10 to 40 μm. Incipient wetness impregnation resulted in gold particles, ranging from 4 to 20 nm, supported on the monoliths. The size of the gold particles depended largely on the crystalline phase of the support, but also on the amount of gold precursor. The catalytic activity of the functionalised materials in liquid-phase oxidation of glucose was higher in continuously stirred batch reactor tests compared to continuous flow fix bed tests. In both cases the activity was improved as the size of gold particles decreased.     

A low-flicker scheme for the real-time measurement of phase noise

This paper presents a new scheme for the measurement of phase noise in real time, based on carrier suppression and synchronous detection of the noise sidebands of the device being tested. In the instruments of the interferometric type, the carrier is suppressed by adding an equal and opposite signal that must be adjusted with a phase shifter and an attenuator. The proposed scheme makes use of a dual adjustment of the carrier suppression, coarse and fine. The former is by-step; the latter is continuous. Because of the higher stability of the by-step adjustment and the lower weight of the continuous adjustment in the suppression circuit, the instrument exhibits intrinsically low residual flicker and low microphonicity. A prototype shows a residual flicker as low as -160 dBrad/sup 2//Hz at 1 Hz off the 100 MHz carrier. Applications include the noise characterization of components and the design of innovative ultrastable oscillators.     

A simple, accurate scheme for the numerical evaluation of integrals with complex singularity poles

The procedure proposed herein is to the authors' best knowledge the only mathematically consistent technique for dealing with general quasi-singularities that occur in the boundary integral equation formulations. Its implementation results in a robust code and implies in no additional computational effort.     

A simple algorithm for localized construction of non‐matching structural interfaces

A simple and effective algorithm for the modular construction of non‐matched interfaces is presented for the partitioned solution of large‐scale structural problems. The formulation is based on a recently developed four‐field variational principle, which introduces a connection frame between the interfaced partitions. A key result of the present study is a frame nodal placement criterion that uniquely determines the frame discretization into piecewise linear elements so that the interface patch test condition is satisfied a priori. The method is demonstrated with several 2D and 3D example problems. Copyright © 2002 John Wiley & Sons, Ltd.     

A simple microwave-based route for size-controlled preparation of colloidal Pt nanoparticles

A simple route for the preparation of colloidal Pt nanoparticles is demonstrated. The formation of such colloids occurs in a single-step process, involving the direct microwave-based heat-treatment of an aqueous solution containing H₂PtCl₆ and 3-thiophenemalonic acid. In the synthesis, the particle size can be controlled by the molar ratio of the reactant agents.     

A simple process for the preparation of photocatalytically active bismuth aluminate nanoparticles

Various amino acids (i.e. phenylalanine, glycine, and arginine) were used in the sol–gel synthesis of Bi₂Al₄O₉ and their effects on the size, morphology and uniformity ofthe product were evaluated through characterizing the products by electron dispersive X-ray spectroscopy, X-ray diffraction, scanning electron microscopy and ultraviolet–visible spectroscopy. Further vibrating sample magnetometery was used for studying the magnetism properties of Bi₂Al₄O₉ sample. The studies on the band gap of the product indicated that the product can have the potentials to act as a photocatalyst in the photo-oxidation of organic dyes under visible irradiation, and it was found that the Bi₂Al₄O₉ lead to the degradation of rhodamine B up to about 92% after 200 min, and hence possesses an effective photocatalytic activity.     

A simple and highly effective process for the preparation of activated carbons with high surface area

Activated carbons with high surface area were prepared by phosphoric acid as activation agent and rice husks as precursors. It was found that the characteristics of the activated carbons were influenced not only by the preparation but also by the post-processing method. The high surface area of the activated carbons was prepared under the optimum condition (50% H₃PO₄ with impregnation ratio of 5:1, activation temperature of 500 °C, activation time of 0.5 h, wash water temperature of 100 °C). SiO₂ content could affect the surface area of activated carbons, either. The lower SiO₂ content of the activated carbons, the higher pore volume the carbons had. The SiO₂ content was 11.2% when used the optimum condition. The explanation was that silicon element in rice husks reacted with H₃PO₄ to form silicon phosphate (SiP₂O₇), and it could be proved further by X-ray diffraction analysis, SiP₂O₇ could be removed by post-process.     

A simple scheme for the finite element solution of a pure advection equation

The present paper deals with the finite element solution of an advection equation. The method of characteristic lines is combined with the finite element method. Three interpolating functions are employed: a cubic, a quadratic and a linear polynomials. The proposed scheme has two key features. One is the simplicity of its algorithm. The other is the combination of the proposed algorithm with the limiting procedure for the purpose of the suppression of numerical oscillations. Three interpolating functions are tested through four numerical examples: the advection of a box-shaped profile, the advection of an elliptic profile, the rotation of a cosine-shaped hill, and the advection of a square-shaped hill. The effectiveness of the proposed scheme is shown by comparing the present numerical results with other popular finite element schemes, i.e., SUPG, Taylor-Galerkin methods and so on. In the present test calculations, the scheme with a quadratic interpolating function has given the best results. The computing time of the proposed scheme is much faster than that of other well-known finite element schemes.     

A simple spatial integration scheme for solving Cauchy problems of non-linear evolution equations

In this study, we address a new and simple non-iterative method to solve Cauchy problems of non-linear evolution equations without initial data. To start with, these ill-posed problems are analysed by utilizing a semi-discretization numerical scheme. Then, the resulting ordinary differential equations at the discretized times are numerically integrated towards the spatial direction by the group-preserving scheme (GPS). After that, we apply a two-stage GPS to integrate the semi-discretized equations. We reveal that the accuracy and stability of the new approach is very good from several numerical experiments even under a large random noisy effect and a very large time span.     

A simple method for the preparation of plasma-sprayable powders based on ZrO2

Plasma-sprayable powders of calcia, magnesia and yttria-stabilized zirconia have been prepared by using polyvinyl alcohol binders. The powders have been characterized for sprayability by spray coating on steel plates previously coated with an NiAl bond coat. The suitability of these coatings for thermal barrier applications have been examined. Thermal barrier and related properties, along with phase stability and mechanical properties, have been found to be good. Failure of the thermal barrier coating has been observed to occur at the interface between the bond coat and the substrate, due to the formation of a pile-up layer consisting of Fe-Zr-Al-O compound.     

A hybrid variational Allen-Cahn/ALE scheme for the coupled analysis of two-phase fluid-structure interaction

We present a partitioned iterative formulation for the modeling of fluid-structure interaction (FSI) in two-phase flows. The variational formulation consists of a stable and robust integration of three blocks of differential equations, viz, an incompressible viscous fluid, a rigid or flexible structure, and a two-phase indicator field. The fluid-fluid interface between the two phases, which may have high density and viscosity ratios, is evolved by solving the conservative phase-field Allen-Cahn equation in the arbitrary Lagrangian-Eulerian coordinates. While the Navier-Stokes equations are solved by a stabilized Petrov-Galerkin method, the conservative Allen-Cahn phase-field equation is discretized by the positivity preserving variational scheme. Fully decoupled implicit solvers for the two-phase fluid and the structure are integrated by the nonlinear iterative force correction in a staggered partitioned manner and the generalized-α method is employed for the time marching. We assess the accuracy and stability of the phase-field/ALE variational formulation for two- and three-dimensional problems involving the dynamical interaction of rigid bodies with free surface. We consider the decay test problems of increasing complexity, namely, free translational heave decay of a circular cylinder and free rotation of a rectangular barge. Through numerical experiments, we show that the proposed formulation is stable and robust for high density ratios across fluid-fluid interface and for low structure-to-fluid mass ratio with strong added-mass effects. Overall, the proposed variational formulation produces results with high accuracy and compares well with available measurements and reference numerical data. Using unstructured meshes, we demonstrate the second-order temporal accuracy of the coupled phase-field/ALE method via decay test of a circular cylinder interacting with the free surface. Finally, we demonstrate the three-dimensional phase-field FSI formulation for a practical problem of internal two-phase flow in a flexible circular pipe subjected to vortex-induced vibrations due to external fluid flow.     

A simple procedure for calculating condensed phase heat of formation of nitroaromatic energetic materials

A simple procedure has been introduced for calculating solid and liquid heats of formation of nitroaromatic energetic compounds. This model assumes that the heat of formation of a nitroaromatic compound of composition C(a)H(b)N(c)O(d) can be expressed as a new correlation which depends on elemental composition and various structural and special functional group parameters. Condensed phase heats of formation predicted using the method described herein and complicated quantum mechanical computations [B.M. Rice, J. Hare, Thermochem. Acta 384 (2002) 377] have a root mean square (rms) deviation of 5.9 and 11.1 kcal/mol for 19 well-known organic nitroaromatic compounds. Predicted heats of formation for 29 polycyclic nitroaromatic energetic compounds have a rms deviation from experiment of 10.6 kcal/mol. The results show that the present method gives comparable prediction respect to the other methods such as complex quantum mechanical computation.