Synchronization of Raman transitions in highly excited hydrogen atoms: A new proposal for measuring the Rydberg constant

We present an analysis of the Raman interaction between a Rydberg atom and ultrashort light pulses. An application of the synchronization of quantum transitions to a simple atomic system (the hydrogen atom) is demonstrated. This is a direct way of measuring times and frequencies of microwave transitions between the high-lying atomic states using ultrashort light pulses. The results and analysis represent a new method for measuring the Rydberg constant.     

A direct method to find solutions of some type of coupled Korteweg-de Vries equations using hyperelliptic functions of genus two

We suggest how one can obtain exact solutions of some type of coupled Korteweg-de Vries equations by means of hyperelliptic functions of genus two.     

Measurement of tortuosity in aluminum foams using airborne ultrasound

The slow compressional wave in air-saturated aluminum foams was studied by means of ultrasonic transverse transmission method over a frequency range from 0.2 MHz to 0.8 MHz. The samples investigated have three different cell sizes or pores per inch (5, 10 and 20 ppi) and each size has three aluminum volume fractions (5%, 8% and 12% AVF). Phase velocities show minor dispersion at low frequencies but remain constant after 0.7 MHz. Pulse broadening and amplitude attenuation are obvious and increase with increasing ppi. Attenuation increases considerably with AVF for 20 ppi foams. Tortuosity ranges from 1.003 to 1.032 and increases with AVF and ppi. However, the increase of tortuosity with AVF is very small for 10 and 20 ppi samples.     

Effect of Local Magnetic Field in G Measurement with Time-of-Swing Method

The effect of the local time- varying magnetic field in our G measurement with the time-of-swing method is studied by magnifying the magnetic field to cause a perceptible change in the pendulum＇s period. The experimental result shows that the coefficients of the change in the period to the magnetic field are 37（1） and 12（1） ms/gauss in the two horizontal directions respectively, which means that the systematic uncertainty due to the local magnetic field is less than 0.4ppm in our G measurement.     

Dispersive optical solitons by Kudryashov's method

This paper studies the dynamics of dispersive optical solitions that is modeled by the fourth order nonlinear Schrödinger's equation and Schrödinger–Hirota equation, the latter of which is considered with power law nonlinearity. Kudryashov's method is applied to obtain soliton solutions to the model equations. These results and the solution methodology makes a profound impact in the study of optical solitons.     

The improved sub-ODE method for a generalized KdV-mKdV equation with nonlinear terms of any order

In this Letter, Li and Wang's sub-ODE method [X.Z. Li, M.L. Wang, Phys. Lett. A 361 (2007) 115] is improved and applied to the generalized KdV-mKdV equation with nonlinear terms of any order. As a result, more travelling wave solutions are obtained including not only all the known solutions found by Li and Wang but also other formal solutions. This improved sub-ODE method can be used for solving other nonlinear partial differential equations with nonlinear terms of any order in mathematical physics.     

New compacton-like and solitary patterns-like solutions to nonlinear wave equations with linear dispersion terms

It has been shown that many fully nonlinear wave equations with nonlinear dispersion terms possess compacton solutions and solitary patterns solutions. In this paper, with the aid of Maple, the mKdV equation, the equation with a source term, the five order KdV-like equation and the KdV–mKdV equation are investigated using some new, generalized transformations. As a consequence, it is shown that these equations with linear dispersion terms admit new compacton-like solutions and solitary patterns-like solutions. These transformations can be also extended to other nonlinear wave equations with nonlinear dispersion terms to seek new compacton-like solutions and solitary patterns-like solutions.     

Orientation of a photo-sensitive polymeric monolayer studied by second-harmonic generation

∞v to C_1v by the photo-isomerization process, with the azobenzene conformation retained as trans-isomer. Received: 5 April 1997     

Detecting the Neutrino

In 1930 Wolfgang Pauli suggested that a new particle might be required to make sense of the radioactive-disintegration mode known as beta decay. This conjecture initially seemed impossible to verify since the new particle, which became known as the neutrino, was uncharged, had zero or small mass, and interacted only insignificantly with other matter. In 1951 Frederick Reines and Clyde L. Cowan, Jr., of the Los Alamos Scientific Laboratory undertook the difficult task of detecting the free neutrino by observing its inverse beta-decay interaction with matter. They succeeded in 1956. The neutrino was accepted rapidly as a fundamental particle despite discrepancies in reported details of the experiments and despite the absence of independent verification of the result. This paper describes the experiments, examines the nature of the discrepancies, and discusses the circumstances of the acceptance of the neutrino's detection by the physics community.     

The study of soliton fission and fusion in (2+1)-dimensional nonlinear system

By means of a variable separation approach and an extended homogeneous balance method, a general variable separation excitation of a (2+1)-dimensional nonlinear system is derived. Based on the derived solution with arbitrary functions, we reveal soliton fission and fusion phenomena in the (2+1)-dimensional soliton system.