Vol. 47, No. 12 (1998)
1998, 47 (12): 1937-1945. doi: 10.7498/aps.47.1937
In this paper,by means of the arbitrariness of the singularity,we have established a new approach of the Painlevé analysis developed by Weiss,Tabor and Carnevale,which is one of the powerful method to study the nonlinear partial differential equations.Selecting some different expansion functions and nonstandard truncations for the KdV equation,we obtained many exact solutions expressed by some complicated implicit functions.
1998, 47 (12): 1946-1951. doi: 10.7498/aps.47.1946
The exact explicit solitary wave solutions for a class of fifth-order nonliear evolution equations are obtained by using a homogeneous method. Particular important cases of the equation, such as Kaup-Kupershmidt, Caudrey-Dodd-Gibbon-Sawada-Kotera and fifth-order KdV equations can be solved by this method.
1998, 47 (12): 1952-1956. doi: 10.7498/aps.47.1952
A damped harmonic oscillator was studied using canonical tramsformation and starting from the method of path integrals.An exact wavefunction for the damped harmonic oscillator has been obtained from a Gaussiantype propagator.The fluctuations of displacement and momentum at zero-point are also given.
1998, 47 (12): 1957-1962. doi: 10.7498/aps.47.1957
The deuterium cluster-ion, which consists of three deuterons, was used to study the cluster effect in the D-D fusion reaction in solids. The cluster-ion beam (deuteron-cluster d+3) and isolated deuteron (single deuteron d+), whose energies were adjusted as from 10 to 100keV per deuteron, were alternatively implanted into deuterium-palladium target. The differences of the fusion reaction rates were obtained by comparing the radiation yields of charged particles and neutrons that were induced by two kinds of beams with the same velocity. Experimental results are as follows: Each deuteron of cluster-ion (cluster deuteron) induced higher D-D fusion rate, compared with an isolated deuteron, when the deuteron energy was lower than 40keV per deuteron; while the cluster deuteron induced lower fusion rate when its energy was higher than 50keV per deuteron. The ratio of fusion rate induced by cluster deuteron to that induced by isolated deuteron decreased with the increase of deuteron energy. Some interpretations have been discussed.
ATOMIC AND MOLECULAR PHYSICS
1998, 47 (12): 1963-1967. doi: 10.7498/aps.47.1963
The selective rules for the Raman spectrum of α-helical protein molecules are given on the basis of the Hamiltonian presented and the laser-Raman spectrum measured on the metabolically active cells.
CLASSICAL AREA OF PHENOMENOLOGY
CLASSIFICATION AND OPTOELECTRONICS IMPLEMENTA-TION OF MULTI-OBJECTS WITH ROTATION INVARIANCE BASED ON RBF FUNCTION
1998, 47 (12): 1968-1975. doi: 10.7498/aps.47.1968
A general discrimination function and a neural network model are constructed by using RBF function.This reveals the close relation between pattern recognition and neural network.Multi-objects classification with in-plane(2-D) and out-plane(3-D) rotation invariance is implemented by using this general discrimination function and neural network model.The computer simulation shows that it is an effective method for classifying multi-objects with rotation invariance.One of the opto-electronics recognition systems is presented to implement this function and model.
1998, 47 (12): 1976-1988. doi: 10.7498/aps.47.1976
Squeezing properties of q-phase-coherent states with respect to the phase quadrature operators are studied.The relations between number-phase squeezing and number-phase uncertainty are also studied in detail for a two-state system.Some new number-phase minimum uncertainty states are found.
1998, 47 (12): 1989-1997. doi: 10.7498/aps.47.1989
By making use of thermo-field dynamics(TFD),higher-order fluctuations and higher-order squeezing of quadrature components for coherent states and squeezed states with thermal noise have been studied.The higher-order fluctuations of the phase for these thermalized states have been investigated using the concept of measured phase operators.Thus the dependence of the lower-and higher-order fluctuations and squeezing on temperature in these states at finite temperature can be seen.It is significant to discuss the effect of temperature on the fluctuations and squeezing,since the states of real field are always at finite temperatures.
1998, 47 (12): 1998-2004. doi: 10.7498/aps.47.1998
Some methods for beam uniformity,such as random phase plate,partially coherent light and “two in one” used in indirect-driven laser fusion,have been studied and analyzed numerically by using the generalized diffraction integral theory.The intensity distributions at the entrance hole and on the wall of a cylindrical hohlraum have been given.The results are useful for the choice of laser uniformity schemes in indirect-driven laser fusion.
PHYSICS OF GASES, PLASMAS, AND ELECTRIC DISCHARGES
1998, 47 (12): 2005-2011. doi: 10.7498/aps.47.2005
In this paper, the charged particle systems energy level seperation in the vertical direction of the magnetic field is considered, according to Boltzmann distribution. Several equations are obtained. The effects are obvious under the condition of low temperature and high intensity magnetic field. Several equations of plasma MHD are corrected.
CONDENSED MATTER: STRUCTURAL, MECHANICAL, AND THERMAL PROPERTIES
1998, 47 (12): 2012-2017. doi: 10.7498/aps.47.2012
Amorphous Fe78Si9B13 specimens have been treated by multiple ultrashort electropulsing with a high current density. The treatment conditions were：1.Keeping the pulse frequency and acting time constant, the current density uninterrupted increases. 2.The pulse frequency increases continuously under constant current density and acting time. The crystallized structures of specimens after electropulsing were investigated by Mssbauer spectroscopy. The results show that the nucleation rate of base metal phase in amorphous specimens increases obviously with the increase of current density and pulse frequency.
1998, 47 (12): 2018-2024. doi: 10.7498/aps.47.2018
The variation of interface structure and composition with heat treatment temperature in Au-GaP contact system are investigated by X-ray photo-emission spectroscopy. The experimental results show that the diffusion and migration between the metal and semiconductor have taken place even if at room temperature. Annealing of Au-GaP contact leads to GaP decomposition in the interface accompanied by rapid atomic interdiffusion. During the increase of temperature the interreaction of Au-Ga atoms is enhanced and AuGa multiphase composition compounds are formed. The interfaces of Au-GaP contact system are an alloying regrowth layer containing metal and semiconductor atoms. The temperature dependence of interface characteristics are discussed from the point of view of Metallurgy.
XPS STUDIES OF CeO2/Nb2O5 INTERFACE EFFECT ON THE IMPROVEMENT OF THE OXYGEN SENSITIVITY OF CeO2 LAYER
1998, 47 (12): 2025-2030. doi: 10.7498/aps.47.2025
The CeO2 single layer and CeO2/Nb2O5 double-layer films have been deposited on a Al2O3 ceramic substrates by a reactive rf/dc sputtering magnetron system. The variation of kinetic behavior of oxygen in CeO2 single layer with temperatures, and also the influence of CeO2/Nb2O5 interface on oxygen sensitivity of the films have been studied by XPS. X-ray photoelectron spectra of Ce3d core level were deconvoluted by Gaussian function for calculating the different concentration of Ce3+ and Ce4+ in the films. The results have shown that the CeO2/Nb2O5 double-layer could improve reduction capability of Ce4+ easily due to the interface effect, so that the reduction capability is higher in CeO2/Nb2O5 double-layer than they were in CeO2 single layer.
CONDENSED MATTER: ELECTRONIC STRUCTURE, ELECTRICAL, MAGNETIC, AND OPTICAL PROPERTIES
1998, 47 (12): 2031-2039. doi: 10.7498/aps.47.2031
Due to the one-dimensional characteristic, the excitation of electrons in polymers will be self-trapped, and two excitons can be combined to form one biexciton. This combination process is one of the most important channels leading to form the biexciton, the efficiency of is much higher than the two-photon process. This kind of combination is accompanied by lattice distortion. By employing the dynamic equation, the relaxation process of this combination is investigated in this paper, and it is found that the relaxation time is about 160fs. The effect of external electrical field on the combination is also studied, the results show that when the electric field E is greater than 0.5MV/cm, instead of the biexciton, two bipolarons are produced.
OPTICAL MICROSCOPIC STUDY OF THE INFLUENCE OF DIFFERENT ELECTRODES ON THE IONIC TRANSPORT CHARACTER OF α-LiIO3
1998, 47 (12): 2040-2045. doi: 10.7498/aps.47.2040
This paper presents an account of our observation on characters of the α-LiIO3 by using a plorazation microscope. The conduction of crystal,the deposition and distribution of the space charges were studied for eight crystal specimens under the actions of the DC electric field in c-direction with five different electrode interface states. The colored quasi-straight bright lines were observed that formed through the transport of the space electric charges of α-LiIO3.There are a correspondence relation between it and the diffraction band of the photo-refractive grating in the crystals, and the different interface states have exerted obvious influence on the ionic transport and crystal conduction in α-LiIO3.
1998, 47 (12): 2046-2052. doi: 10.7498/aps.47.2046
The room temperature magnetoresistance (MR) and hysteresis in the wire arrays of Fe/［NiFe/Cu］30 muitilayer were investigated. These arrays were fabricated by laser lithography and ion beam etching techniques. The magnetic properties of the wire array is distinctly different compared with the continous film. the maximum MR ratio is increased for some arrays, and for some other arrays this MR ratio is decreased. A marked increased in coercivity of some arrays is seen for the field applied along the wire axis, but for some other arrays the coercivity almost remains constant. These results depend on the defferene in interlayer exchange coupling for original continous films and also depend on the uniaxial anisotroy and the other change caused by the wire fabrication of array.
DEFLECTION CHARACTERISTICS OF SPLIT ELECTRODE INPLANE BENDING PIEZOELECTRIC ACTUATORS WITH VARYING WIDTH
1998, 47 (12): 2053-2063. doi: 10.7498/aps.47.2053
The cantilever split-morph, a new type of piezoelectric actuator, have been designed for dual-stage head positioning servo system of high density hard disk drives. In this actuator configuration, a PZT ceramic plate, with one end mechanically clamped and the other free, was poled along its thickness and divided into two symmetric parts along length by splitting electrodes. Driving voltages are preferably so arranged that they make one of the two parts expand by the “31”action while the other part, i.e., the symmetric part, contracts. This will result in a bending motion of the actuator along the direction of its width. The driving voltage-tip displacement characteristics of the actuator have been investigated by theoretical analysis, finite element modeling and experiment. Theoretical analysis indicated that the electric field induced stress is much smaller than stretch strength of piezoelectric ceramic. Tip displacement measured by Michelson interferometer is a little larger than the calculated result. This is mainly due to the increase of piezoelectric coefficient d31 at high driving field. Tip displacement of 1 to 2μm can be achieved at 20 to 50V driving voltage for the split-morph whose size is similar to that of the existing suspension. As to 25 kTPI (track per inch) high track density hard disk drives, this actuating stroke can cover at least one track width and meet the primary requirements of dual-stage head positioning servo system for displacement of the secondary actuator.
1998, 47 (12): 2064-2073. doi: 10.7498/aps.47.2064
The mechanical properies of intermetallics in Ti-Al alloy system are studied systematically from the view point of valence electron by the empirical electron theory (EET). First, according to the basic thinking of the EET, space topology of valence electron structure is modelled, and the embrittlement nature of intermetallics in Ti-Al system is concisely brought to light. Second, the valence electron structure symmetry factor α, which has a good relationship to the plasticity is proposed from the model, and the embrittlement criterion is summed up. Finally, the empirical relation between valence electron structures and mechanical properties can be established.
GEOPHYSICS, ASTRONOMY, AND ASTROPHYSICS
1998, 47 (12): 2074-2078. doi: 10.7498/aps.47.2074
For the black hole having Hawking radiation, it must have effect on the space-time metric (the so-called back-reaction). By combination of the result from themodynamical approach with the back-reaction of the black hole and the semiclassical Einstein equation, we get the modified Schwarzschild space-time metric. This method is much more simple and convenient than that of Jork's.