A new class of spherically symmetric interior solution with cosmological constant Λ

In this paper, a new class of spherically symmetric interior solution with cosmological constant is obtained, to which Florides' solution is extended. As a special case, the metric in uniform proper density is discussed. The Robson junction condition is also extended to the case with nonvanishing, which is a set of necessary and sufficient conditions for a spherically symmetric metric to join smoothly onto the vacuum metric at a nonnull boundary surface. The new solution satisfies the extended Robson condition.     

On the representation of long-range potentials by a [1, 0] Padé approximant

The utility of the [1, 0] Padé approximant in the determination of long-range interaction constants is investigated using the recently calculated Rydberg-Klein-Rees potentials for the B³Π_Ou ⁺ states of I₂, Br₂ and Cl₂. The conditions under which the [1, 0] Padé approximant is a valid representation of the long-range potential outside the electron-overlap region are studied in detail, using as model systems the B states of I₂, Br₂ and Cl₂, and the X¹Σg⁺, B¹Σu⁺ and B′¹Σu⁺ states of H₂. In general, the validity of the representation depends on the nature of the potential, and is governed by

if the long-range potential can be adequately represented by a maximum number of three terms (n, m, m1) in the inverse-power expansion.     

Comparison of the calculated electronic structures of [111] and [001] GaAs/AℓxGa1-xAs semiconductor superlattices

A theoretical comparison of the electronic structures of long-period (about 300 Å) N_GaAs×N_AℓGaAs GaAs/Aℓ_0.3Ga_0.7As superlattices grown along the [111] direction and superlattices grown along the [001] direction is presented. Almost all qualitative features of the theoretical results are in good agreement with experiments by Hayakawa et al. The observed optical transition enhancement in the [111]-oriented quantum-well structures is caused by the topological difference in the superlattices, and is only partly due to the fact that the heavy holes in the [111] superlattices have larger transverse effective masses, and therefore have larger two-dimensional valence band densities of states.     

Iterative solutions for low lying excited states of a class of SchrSdinger equation

The convergent iterative procedure for solving the groundstate Schr?dinger equation is extended to derive the excitation energy and the wavefunction of the low-lying excited states. The method is applied to the one-dimensional quartic potential problem. The results show that the iterative solution converges rapidly when the coupling g is not too small.     

A new method of new exact solutions and solitary wave-like solutions for the generalized variable coefficients Kadomtsev——Petviashvili equation

Using the solution of general Korteweg--de Vries (KdV) equation, the solutions of the generalized variable coefficient Kadomtsev--Petviashvili (KP) equation are constructed, and then its new solitary wave-like solution and Jacobi elliptic function solution are obtained.     

A new class of realizations of the lie algebragl(n + 1, ℓ)

In this paper, we apply the previously published method (J. Phys. A18(1985) 3101) to the construction of boson realizations for Lie algebrasgl(n + 1, ). These realizations are expressed by means of certain recurrent formulae in terms ofr(n + 1 – r) canonical pairs and generators of the subalgebragl(r, ) + gl(n + 1 – r, ), wherer = 1,2,...,n. They are skew-Hermitean and Schurean.Dedicated to the 30th anniversary of the Joint Institute for Nuclear Research.On leave of absence from theNuclear Centre of the Faculty of Mathematics and Physics, V Holeovikách 2, 180 00 Praha 8, Czechoslovakia.The author is grateful to Drs. P. Exner, M. Havliek and O. Navrátil for useful discussions.     

Exact solutions of a new elliptic Calogero–Sutherland model

A quantum Hamiltonian describing N particles on a line interacting pairwise via an elliptic function potential in the presence of an external field is introduced. For a discrete set of values of the strength of the external potential, it is shown that a finite number of eigenfunctions and eigenvalues of the model can be exactly computed in an algebraic way.     

A new class of Abelian theorems for the Mehler–Fock transforms

The main object of this paper is to derive several new Abelian theorems for the Mehler–Fock transforms. The results presented here are compared with those given earlier by R. S. Pathak and R. N. Pandey [Math. Soc. 3 (1987), 91–95]. Some applications and particular cases are also considered.     

Exact and approximate solutions of Schrödinger’s equation for a class of trigonometric potentials

The asymptotic iteration method is used to find exact and approximate solutions of Schrödinger’s equation for a number of one-dimensional trigonometric potentials (sine-squared, double-cosine, tangent-squared, and complex cotangent). Analytic and approximate solutions are obtained by first using a coordinate transformation to reduce the Schrödinger equation to a second-order differential equation with an appropriate form. The asymptotic iteration method is also employed indirectly to obtain the terms in perturbation expansions, both for the energies and for the corresponding eigenfunctions.     

A new demodulation technique for optical fiber interferometric sensors with[3×3]directional couplers

Optical fiber interferometric sensors based on[3×3]couplers have been used in many fields.A new technique is proposed to demodulate output signals of this kind of sensors.The technique recovers the signal of interest by fitting coefficients of elliptic(Lissajous)curves between each fiber pair.Different from other approaches,this technique eliminates the dependence on the idealization of[3×3]coupler,provides enhanced tolerance to the variance of photoelectric converters.and is anti-polarization in a certain extent. The main algorithm has been successfully demonstrated both by numerical simulation and experimental result.     

A new approach to produce amino-carbon nanotubes as plasmid transfection vector by [2 + 1] cycloaddition of nitrenes

Amino-carbon nanotubes (amino-CNTs) can conjugate with the DNA by electrostatic interactions and shuttle the DNA to the cell cytoplasm or even the nucleus. Here we report a new approach to produce amino-CNTs by cycloaddition of nitrenes. Fourier transform infrared spectroscopy was used to verify the success of the functionalization, and the functionalization degree was calculated by thermal gravity analysis. Transmission electron microscope (TEM) was used to observe the solubility of the CNTs and the interactions of the amino-CNTs with the plasmids. Cell ultrathin sections were made and observed under the TEM to confirm the amino-CNTs enter the cells. Transfection experiments ultimately verify the amino-CNTs produced through cycloadditions of nitrenes can serve as plasmid vector.     

A facile one-pot ultrasound assisted for an efficient synthesis of 1H-spiro[furo[3,4-b]pyridine-4,3′-indoline]-3-carbonitriles

A convenient one-pot protocol was developed for the synthesis of 1H-spiro[furo[3,4-b]pyridine-4,3′-indoline]-3-carbonitrile derivatives. This reaction was carried out through a three component condensation reaction of isatins, malononitrile, and anilinolactones in the presence of a catalytic amount of Et₃N as an inexpensive and available basic catalyst in THF under ultrasound irradiation. The products were obtained in high yields and short reaction times. The main advantage of this synthetic method is that the obtained products in ultrasonic irradiations are different from classical heating.     

Influence of Intrinsic Decoherence on Nonclassical Effects of System of a Three-LevelAtom in [1] Configuration

With the help of an SU(3) dynamicalalgebraic structure, we ~nd an exact solutionof the Milburn equationfor the system of a three-levelatom in the [1] configuration interacting with one quantized field mode with arbitrary detuning ,The exact solution is then used to discuss the influence of the intrinsic decoherence on the nonclassical properties of the system,such as collapes and revivals of the atomic populations,oscillations of the photon number distribution,and squeezing of the radiation field.     

Residual symmetries,consistent-Riccati-expansion integrability,and interaction solutions of a new (3+1)-dimensional generalized Kadomtsev—Petviashvili equation

With the aid of the Painlevé analysis, we obtain residual symmetries for a new (3+1)-dimensional generalized Kadomtsev—Petviashvili (gKP) equation. The residual symmetry is localized and the finite transformation is proposed by introducing suitable auxiliary variables. In addition, the interaction solutions of the (3+1)-dimensional gKP equation are constructed via the consistent Riccati expansion method. Particularly, some analytical soliton-cnoidal interaction solutions are discussed in graphical way.     

A series of new double periodic solutions to a (2+1)-dimensional asymmetric Nizhnik－Novikov－Veselov equation

By means of a new general ans?tz and with the aid of symbolic computation, a new algebraic method named Jacobi elliptic function rational expansion is devised to uniformly construct a series of new double periodic solutions to (2+1)-dimensional asymmetric Nizhnik－Novikov－Veselov (ANNV) equation in terms of rational Jacobi elliptic function.     

Elasto-dipolar magnons—a new class of nonexchange spin-wave excitations

Interference of phonon and magnetic dipolar spin-spin interaction mechanisms in a finite magnet can result in a previously unexplored class of nonexchange spin waves.     

A new method for generating nonclassical correlation state of the light in a open-loop LED system

The nonclassical correlation state of the light have been investigated experimentally in re-cent years.After the open-type amplitude squeezed state of the light has been observed experi-mentally,we have generated and observed nonclassical correlation state of the light deep sup-pression in a open-loop LED system with very simple setup.The experimental apparatus isshown in Fig.1.In which,a closed-loop Ch1 is consist of LED1,PD1,A1,A3 and low-noise     

A new unified theory for scattering of a bounded acoustic beam from a liquid-solid interface near the Rayleigh angle

For scattering of a bounded acoustic beam from a liquid-solidinterface,the principal difficulty comes from the treatment of the plane wave reflec-tion coefficient.In the Present paper,following the Singularity Expansion Method,the reflection coefficient is expanded into the sum of an analytic function(constant1)and the principal part of the Laurent expansion in the neighborhood of theRayleigh pole.The scattered field is now evaluated by a double integral in thewavenumber and interface planes.The constant 1 produces a rigid boundary geo-metrical reflected beam,and the expansions at the Rayleigh poles yield the leakyRayleigh waves.It is particularly proved that the residues of the poles are nearlyproportional to the imaginary parts of the poles for most liquid-solid interfaces.Therefore,the complex pole may determine the whole behavior of the leakyRayleigh wave,including the excitation and reradiation efficiencies.For thebackscattered field,since the negative Rayleigh pole plays a major role,a back-ward l     

Measurement of the vector A y and tensor A yy , A xx , A xz analyzing powers for the dd → 3H p reaction at 200 MeV

The data on the vector A _y and tensor A _yy , A _xx , A _xz analyzing powers for the d → ³H p reaction have been obtained at the energy of the initial deuteron of 200MeV in the angular range of 0–95 degrees in the c.m.s. The calculations performed within one-nucleon exchange model with the use of the standard three-nucleon bound state wave functions fail to reproduce the data on the tensor analyzing powers.