Acta Physica Sinica - //m.suprmerch.com/ daily 15 2024-11-21 09:34:02 apsoffice@iphy.ac.cn apsoffice@iphy.ac.cn 2024-11-21 09:34:02 zh Copyright ©Acta Physica Sinica All Rights Reserved.  Address: PostCode:100190 Phone: 010-82649829,82649241,82649863 Email: apsoffice@iphy.ac.cn Copyright ©Acta Physica Sinica All Rights Reserved apsoffice@iphy.ac.cn 1000-3290 <![CDATA[RADIATING OF ACCELERATING CHARGE IN GENERAL RELATIVITY]]> //m.suprmerch.com/en/article/doi/10.7498/aps.48.561

Based on the previous paper, for accelerating charge in general relativity, we obtained the exact expressions of electromagnetic field and radiating energy.


Acta Physica Sinica. 1999 48(4): 561-565. Published 1999-02-05 ]]>

Based on the previous paper, for accelerating charge in general relativity, we obtained the exact expressions of electromagnetic field and radiating energy.


Acta Physica Sinica. 1999 48(4): 561-565. Published 1999-02-05 ]]>
1999-02-20T00:00:00+00:00 Personal use only, all commercial or other reuse prohibited Acta Physica Sinica. 1999 48(4): 561-565. article doi:10.7498/aps.48.561 10.7498/aps.48.561 Acta Physica Sinica 48 4 1999-02-05 //m.suprmerch.com/en/article/doi/10.7498/aps.48.561 561-565
<![CDATA[DOUBLE-WAVE DESCRIPTION OF ONE-DIMENSIONAL HYDROGEN ATOM]]> //m.suprmerch.com/en/article/doi/10.7498/aps.48.566

Stationary solutions of one-dimensional hydrogen atom are two-degree degenerate. Three kinds of typical solutions can be constructed from those degenerated solutions. They correspond to three kinds of ensembles. Double-wave theory describes a single hydrogen atom. When three different averages over ensembles are made for double-wave theory, three kinds of typical solutions in the usual quantum mechanics are obtained. A comparison between these solutions and those of classical mechanics is made.


Acta Physica Sinica. 1999 48(4): 566-574. Published 1999-02-05 ]]>

Stationary solutions of one-dimensional hydrogen atom are two-degree degenerate. Three kinds of typical solutions can be constructed from those degenerated solutions. They correspond to three kinds of ensembles. Double-wave theory describes a single hydrogen atom. When three different averages over ensembles are made for double-wave theory, three kinds of typical solutions in the usual quantum mechanics are obtained. A comparison between these solutions and those of classical mechanics is made.


Acta Physica Sinica. 1999 48(4): 566-574. Published 1999-02-05 ]]>
1999-02-20T00:00:00+00:00 Personal use only, all commercial or other reuse prohibited Acta Physica Sinica. 1999 48(4): 566-574. article doi:10.7498/aps.48.566 10.7498/aps.48.566 Acta Physica Sinica 48 4 1999-02-05 //m.suprmerch.com/en/article/doi/10.7498/aps.48.566 566-574
<![CDATA[QUANTUM ERGOSPHERE EFFECT OF SPHERICALLY SYMMETRIC NON-STATIC BLACK HOLE]]> //m.suprmerch.com/en/article/doi/10.7498/aps.48.575

By means of the Newman-Penrose formalism,the gravitational,electromagnetic, scalar and Dirac fields in spherically symmetric non-static space-times are discussed.It is shown that the quantum ergosphere can influence the radiative mechanism of a non-static black hole.The character of the effect is that the radiative mechanism is obviously dependent on the spin state,which differs from the classical effects due to the Kerr ergosphere and the electromagnetic potential.


Acta Physica Sinica. 1999 48(4): 575-580. Published 1999-02-05 ]]>

By means of the Newman-Penrose formalism,the gravitational,electromagnetic, scalar and Dirac fields in spherically symmetric non-static space-times are discussed.It is shown that the quantum ergosphere can influence the radiative mechanism of a non-static black hole.The character of the effect is that the radiative mechanism is obviously dependent on the spin state,which differs from the classical effects due to the Kerr ergosphere and the electromagnetic potential.


Acta Physica Sinica. 1999 48(4): 575-580. Published 1999-02-05 ]]>
1999-02-20T00:00:00+00:00 Personal use only, all commercial or other reuse prohibited Acta Physica Sinica. 1999 48(4): 575-580. article doi:10.7498/aps.48.575 10.7498/aps.48.575 Acta Physica Sinica 48 4 1999-02-05 //m.suprmerch.com/en/article/doi/10.7498/aps.48.575 575-580
<![CDATA[A MODIFIED PERIODIC PULSE METHOD TO CONTROL THE CHAOS OF CONSERVATIVE FLOW]]> //m.suprmerch.com/en/article/doi/10.7498/aps.48.581

Firstly, we find out the convergent scope in limited time of the conservation flow x…+x·-x2+B=0 (0≤B≤0.005) in a certain time, whose scope Lyapunov exponents is below zero, and restrained in Poincaré section, and then get the steady periodic orbits through periodic pulse method. With the above-mentioned rule, we can control systematic high periodic orbits.This rule is, to some extent, robust against external noise.


Acta Physica Sinica. 1999 48(4): 581-588. Published 1999-02-05 ]]>

Firstly, we find out the convergent scope in limited time of the conservation flow x…+x·-x2+B=0 (0≤B≤0.005) in a certain time, whose scope Lyapunov exponents is below zero, and restrained in Poincaré section, and then get the steady periodic orbits through periodic pulse method. With the above-mentioned rule, we can control systematic high periodic orbits.This rule is, to some extent, robust against external noise.


Acta Physica Sinica. 1999 48(4): 581-588. Published 1999-02-05 ]]>
1999-02-20T00:00:00+00:00 Personal use only, all commercial or other reuse prohibited Acta Physica Sinica. 1999 48(4): 581-588. article doi:10.7498/aps.48.581 10.7498/aps.48.581 Acta Physica Sinica 48 4 1999-02-05 //m.suprmerch.com/en/article/doi/10.7498/aps.48.581 581-588
<![CDATA[CONTROLLING HYPERCHAOS THROUGH LENGTHENING TIME OF AUTOCORRELATION OF SIGNAL]]> //m.suprmerch.com/en/article/doi/10.7498/aps.48.589

The method of Lengthening time of autocorrelation of signal is used to control hyperchaotic behavior in nonlinear continuous system. The Rossler and CLHE hyperchaotic system are taken as two typical examples. The numberical simulations show that the behavior of hyperchaos in a nonlinear system is controlled effectively and a series of stable periodic orbits are obtained by the method in this paper. The choice of control parameter is independent of controlled hyperchaotic systems in principle.


Acta Physica Sinica. 1999 48(4): 589-595. Published 1999-02-05 ]]>

The method of Lengthening time of autocorrelation of signal is used to control hyperchaotic behavior in nonlinear continuous system. The Rossler and CLHE hyperchaotic system are taken as two typical examples. The numberical simulations show that the behavior of hyperchaos in a nonlinear system is controlled effectively and a series of stable periodic orbits are obtained by the method in this paper. The choice of control parameter is independent of controlled hyperchaotic systems in principle.


Acta Physica Sinica. 1999 48(4): 589-595. Published 1999-02-05 ]]>
1999-02-20T00:00:00+00:00 Personal use only, all commercial or other reuse prohibited Acta Physica Sinica. 1999 48(4): 589-595. article doi:10.7498/aps.48.589 10.7498/aps.48.589 Acta Physica Sinica 48 4 1999-02-05 //m.suprmerch.com/en/article/doi/10.7498/aps.48.589 589-595
<![CDATA[TRANSITION PROPERTIES OF HIGHLY-EXCITED STATES OF Yb ATOM]]> //m.suprmerch.com/en/article/doi/10.7498/aps.48.596

The rates of blackbody rediation induced transitions and spontaneous transitions of Rydberg states and Stark states of ytterbium have been calculated by the method of numerical integration based on the hydrogenic model. The calculated results are compared with experimental data measured by using delayed electric field ionization. In addition, we have chosen the typically initial states to observe the distribution of repopulations among nearby states and given theoretical explanation. The availability of the hydrogenic model when applied to highly-excited states of complex atoms is discussed.


Acta Physica Sinica. 1999 48(4): 596-602. Published 1999-02-05 ]]>

The rates of blackbody rediation induced transitions and spontaneous transitions of Rydberg states and Stark states of ytterbium have been calculated by the method of numerical integration based on the hydrogenic model. The calculated results are compared with experimental data measured by using delayed electric field ionization. In addition, we have chosen the typically initial states to observe the distribution of repopulations among nearby states and given theoretical explanation. The availability of the hydrogenic model when applied to highly-excited states of complex atoms is discussed.


Acta Physica Sinica. 1999 48(4): 596-602. Published 1999-02-05 ]]>
1999-02-20T00:00:00+00:00 Personal use only, all commercial or other reuse prohibited Acta Physica Sinica. 1999 48(4): 596-602. article doi:10.7498/aps.48.596 10.7498/aps.48.596 Acta Physica Sinica 48 4 1999-02-05 //m.suprmerch.com/en/article/doi/10.7498/aps.48.596 596-602
<![CDATA[SPONTANEOUS EMISSION FROM A THREE-LEVEL ATOM IN PHOTONIC CRYSTAL]]> //m.suprmerch.com/en/article/doi/10.7498/aps.48.603

Spontaneous emission from a three-level atom in a photonic crystal is investigated. As a result of quantum interference and photon localization, the populations in the two upper levels displays oscillatory or quasioscillatory behavior. This depends on the relative positon of the two upper levels from forbidden gap and the initial state of atom. These Properties differ from those of three-level atom in vacuum.


Acta Physica Sinica. 1999 48(4): 603-610. Published 1999-02-05 ]]>

Spontaneous emission from a three-level atom in a photonic crystal is investigated. As a result of quantum interference and photon localization, the populations in the two upper levels displays oscillatory or quasioscillatory behavior. This depends on the relative positon of the two upper levels from forbidden gap and the initial state of atom. These Properties differ from those of three-level atom in vacuum.


Acta Physica Sinica. 1999 48(4): 603-610. Published 1999-02-05 ]]>
1999-02-20T00:00:00+00:00 Personal use only, all commercial or other reuse prohibited Acta Physica Sinica. 1999 48(4): 603-610. article doi:10.7498/aps.48.603 10.7498/aps.48.603 Acta Physica Sinica 48 4 1999-02-05 //m.suprmerch.com/en/article/doi/10.7498/aps.48.603 603-610
<![CDATA[ATOM LITHOGRAPHY]]> //m.suprmerch.com/en/article/doi/10.7498/aps.48.611

A new nanometer lithographic techniqueatom lithography,which is developed based on the principles of laser cooling and trapping of neutral atomsthe newest achievements of quantum optics,has been reviewed.The working principles,the overall schemes,the individual techniques and the acquired results are described.This new method has been compared with the existing micro-lithographic techniques,and the application potentialities in the micro-electronics and other fields have been discussed.


Acta Physica Sinica. 1999 48(4): 611-619. Published 1999-02-05 ]]>

A new nanometer lithographic techniqueatom lithography,which is developed based on the principles of laser cooling and trapping of neutral atomsthe newest achievements of quantum optics,has been reviewed.The working principles,the overall schemes,the individual techniques and the acquired results are described.This new method has been compared with the existing micro-lithographic techniques,and the application potentialities in the micro-electronics and other fields have been discussed.


Acta Physica Sinica. 1999 48(4): 611-619. Published 1999-02-05 ]]>
1999-02-20T00:00:00+00:00 Personal use only, all commercial or other reuse prohibited Acta Physica Sinica. 1999 48(4): 611-619. article doi:10.7498/aps.48.611 10.7498/aps.48.611 Acta Physica Sinica 48 4 1999-02-05 //m.suprmerch.com/en/article/doi/10.7498/aps.48.611 611-619
<![CDATA[THE STUDY OF LASER-INDUCED LOCAL HEATING OF MO MULTILAYER]]> //m.suprmerch.com/en/article/doi/10.7498/aps.48.620

For a TbFeCo quadrilayer illuminated by laser beam,absorption of the laser power within different layers was considered by analysizing the rate of absorption of energy per unit volume.With the help of implicit method,the profile of temperature of the multilayer was given and the diffusion of heat was studied.The effect of laser power,laser duration and the convection loss at the front surface upon the thermal characteristics of the multilayer was investigated.This thermal analysis procedure provided a good example for the thermal investigation within other optical disk systems.


Acta Physica Sinica. 1999 48(4): 620-627. Published 1999-02-05 ]]>

For a TbFeCo quadrilayer illuminated by laser beam,absorption of the laser power within different layers was considered by analysizing the rate of absorption of energy per unit volume.With the help of implicit method,the profile of temperature of the multilayer was given and the diffusion of heat was studied.The effect of laser power,laser duration and the convection loss at the front surface upon the thermal characteristics of the multilayer was investigated.This thermal analysis procedure provided a good example for the thermal investigation within other optical disk systems.


Acta Physica Sinica. 1999 48(4): 620-627. Published 1999-02-05 ]]>
1999-02-20T00:00:00+00:00 Personal use only, all commercial or other reuse prohibited Acta Physica Sinica. 1999 48(4): 620-627. article doi:10.7498/aps.48.620 10.7498/aps.48.620 Acta Physica Sinica 48 4 1999-02-05 //m.suprmerch.com/en/article/doi/10.7498/aps.48.620 620-627
<![CDATA[A THEORETICAL STUDY ON Li+(1s2)(e,2e) REACTIONS IN COPLANAR DOUBLY SYMMETRIC GEOMETRY]]> //m.suprmerch.com/en/article/doi/10.7498/aps.48.628

Based on the Berakdar theory,this work investigates theoretically the triply differential cross sections for electron impact ionization of Li+(1s2) at an energy of 100eV in coplanar doubly symmetric geometry,i.e.,equal energies and equal emission angles for the two electrons in the final state.Dominant ionization mechanisms are identified and the contribution of different scattering amplitudes and the major role of initial channel Coulomb field are discussed.It turns out that the cross section in doubly symmetric geometry is strongly influenced by the interference of these amplitudes and the initial channel Coulomb field.


Acta Physica Sinica. 1999 48(4): 628-632. Published 1999-02-05 ]]>

Based on the Berakdar theory,this work investigates theoretically the triply differential cross sections for electron impact ionization of Li+(1s2) at an energy of 100eV in coplanar doubly symmetric geometry,i.e.,equal energies and equal emission angles for the two electrons in the final state.Dominant ionization mechanisms are identified and the contribution of different scattering amplitudes and the major role of initial channel Coulomb field are discussed.It turns out that the cross section in doubly symmetric geometry is strongly influenced by the interference of these amplitudes and the initial channel Coulomb field.


Acta Physica Sinica. 1999 48(4): 628-632. Published 1999-02-05 ]]>
1999-02-20T00:00:00+00:00 Personal use only, all commercial or other reuse prohibited Acta Physica Sinica. 1999 48(4): 628-632. article doi:10.7498/aps.48.628 10.7498/aps.48.628 Acta Physica Sinica 48 4 1999-02-05 //m.suprmerch.com/en/article/doi/10.7498/aps.48.628 628-632
<![CDATA[THE ELECTRONIC STRUCTURE AND STABILITY OF M@C28 (M=Ti,Zr,Hf) ENDOHEDRAL COMPLEXES]]> //m.suprmerch.com/en/article/doi/10.7498/aps.48.633

We have studied the electronic structure of M@C28(M=Ti,Zr,Hf) endohedral complexes with ab initio method in B3-LYP effective core potential model and density functional theory.The computations were carried out for the geometry optimizations,which determined the structure constants of atoms in ground states,and the analysis of natural bond orbital.The interaction of Ti atom and C28 cluster was very different from that of Zr (or Hf) atom and C28 cluster. It occurred on the atomic configuration,the bonding character and the distribution of electronic states etc.According to the estimation of binding energy,three complexes could exist stably,and Zr@C28 and Hf@C28 were more stable than Ti@C28.The results have been analyzed and discussed,also compared with those in the literatare.


Acta Physica Sinica. 1999 48(4): 633-641. Published 1999-02-05 ]]>

We have studied the electronic structure of M@C28(M=Ti,Zr,Hf) endohedral complexes with ab initio method in B3-LYP effective core potential model and density functional theory.The computations were carried out for the geometry optimizations,which determined the structure constants of atoms in ground states,and the analysis of natural bond orbital.The interaction of Ti atom and C28 cluster was very different from that of Zr (or Hf) atom and C28 cluster. It occurred on the atomic configuration,the bonding character and the distribution of electronic states etc.According to the estimation of binding energy,three complexes could exist stably,and Zr@C28 and Hf@C28 were more stable than Ti@C28.The results have been analyzed and discussed,also compared with those in the literatare.


Acta Physica Sinica. 1999 48(4): 633-641. Published 1999-02-05 ]]>
1999-02-20T00:00:00+00:00 Personal use only, all commercial or other reuse prohibited Acta Physica Sinica. 1999 48(4): 633-641. article doi:10.7498/aps.48.633 10.7498/aps.48.633 Acta Physica Sinica 48 4 1999-02-05 //m.suprmerch.com/en/article/doi/10.7498/aps.48.633 633-641
<![CDATA[ENERGY,STRUCTURE AND RELATED TOPOLOGICAL PROPERTY OF BERYLLIUM CLUSTERS:2≤n≤25]]> //m.suprmerch.com/en/article/doi/10.7498/aps.48.642

We investigated the energy,structure and related topological property of beryllium clusters bound by a recently developed first-principles many-body potential(Estela Blaisten-Barojas and S.N.Khanna,Phys.Rev.Lett.,61(1988),1477).A modified cluster structure optimization method based on the genetic algorithms was used to search for the global minimum of the potential.Dependence of the energy,structure and related topological property of beryllium clusters Ben(n=2—25) on cluster size was elucidated;and a systematic structure comparison of Ben with metal cluster Mn and rare-gas cluster LJn bound by long-range Morse potential and Lennard-Jones potential,respectively,was presented.Our results showed that structures of Ben,in the range of n=2—25,can be categorized as either Mn-like or LJn-like,and many-body contributions of the potential appears to play a significant role in determining the most stable structures in beryllium systems.


Acta Physica Sinica. 1999 48(4): 642-649. Published 1999-02-05 ]]>

We investigated the energy,structure and related topological property of beryllium clusters bound by a recently developed first-principles many-body potential(Estela Blaisten-Barojas and S.N.Khanna,Phys.Rev.Lett.,61(1988),1477).A modified cluster structure optimization method based on the genetic algorithms was used to search for the global minimum of the potential.Dependence of the energy,structure and related topological property of beryllium clusters Ben(n=2—25) on cluster size was elucidated;and a systematic structure comparison of Ben with metal cluster Mn and rare-gas cluster LJn bound by long-range Morse potential and Lennard-Jones potential,respectively,was presented.Our results showed that structures of Ben,in the range of n=2—25,can be categorized as either Mn-like or LJn-like,and many-body contributions of the potential appears to play a significant role in determining the most stable structures in beryllium systems.


Acta Physica Sinica. 1999 48(4): 642-649. Published 1999-02-05 ]]>
1999-02-20T00:00:00+00:00 Personal use only, all commercial or other reuse prohibited Acta Physica Sinica. 1999 48(4): 642-649. article doi:10.7498/aps.48.642 10.7498/aps.48.642 Acta Physica Sinica 48 4 1999-02-05 //m.suprmerch.com/en/article/doi/10.7498/aps.48.642 642-649
<![CDATA[ELECTRON DYNAMICS IN THE EXTRA-INTENSE STATIONARY LASER FIELD]]> //m.suprmerch.com/en/article/doi/10.7498/aps.48.650

Electron dynamics in the extra-intense stationary laser field has been investigated by numerical simulation method.It is found,for the first time to our knowledge,that when Q100(Q=eE/mecω,is a dimensionless parameter measuring the field intenstiy),the electron with relatively lower energy can be captured and violently accelerated by the laser beam.This is a new phenmenon which is of potential importance to the far-field laser acceleration in vacuum.


Acta Physica Sinica. 1999 48(4): 650-660. Published 1999-02-05 ]]>

Electron dynamics in the extra-intense stationary laser field has been investigated by numerical simulation method.It is found,for the first time to our knowledge,that when Q100(Q=eE/mecω,is a dimensionless parameter measuring the field intenstiy),the electron with relatively lower energy can be captured and violently accelerated by the laser beam.This is a new phenmenon which is of potential importance to the far-field laser acceleration in vacuum.


Acta Physica Sinica. 1999 48(4): 650-660. Published 1999-02-05 ]]>
1999-02-20T00:00:00+00:00 Personal use only, all commercial or other reuse prohibited Acta Physica Sinica. 1999 48(4): 650-660. article doi:10.7498/aps.48.650 10.7498/aps.48.650 Acta Physica Sinica 48 4 1999-02-05 //m.suprmerch.com/en/article/doi/10.7498/aps.48.650 650-660
<![CDATA[REALIZATION OF A SPIN-TYPE GHZ STATE VIA THE JAYNES-CUMMINGS MODEL WITH LARGE DETUNING]]> //m.suprmerch.com/en/article/doi/10.7498/aps.48.661

Realization of a spin-type Greenberger-Horne-Zeilinger state via the Jaynes-Cummings model with large detuning is presented.The contradiction to local hidden variable theory is made through measuring the parity of the cavity fields. This scheme does not violate Bell's inequality.


Acta Physica Sinica. 1999 48(4): 661-666. Published 1999-02-05 ]]>

Realization of a spin-type Greenberger-Horne-Zeilinger state via the Jaynes-Cummings model with large detuning is presented.The contradiction to local hidden variable theory is made through measuring the parity of the cavity fields. This scheme does not violate Bell's inequality.


Acta Physica Sinica. 1999 48(4): 661-666. Published 1999-02-05 ]]>
1999-02-20T00:00:00+00:00 Personal use only, all commercial or other reuse prohibited Acta Physica Sinica. 1999 48(4): 661-666. article doi:10.7498/aps.48.661 10.7498/aps.48.661 Acta Physica Sinica 48 4 1999-02-05 //m.suprmerch.com/en/article/doi/10.7498/aps.48.661 661-666
<![CDATA[A NEW CONFIGURATION OF THE LASER CAVITY FOR SIMULTANEOUS DUAL WAVELENGTH Q-SWITCH PULSED Nd∶YAlO3 LASER]]> //m.suprmerch.com/en/article/doi/10.7498/aps.48.667

Based on the rate equations of the Q-Switch simultaneous dual wavelength laser (SDWL) of Nd∶YAlO3 (Nd∶YAP), we have developed a new configuration of the cavity by adjusting the ratio of the cavity lengths for lasers with different wavelengths according to their emission cross sections. Therefore the competition ability and the net gain for the two different wavelengths will be equal at any time and anywhere in the laser rod, and the optimal spatial and temporal overlap of the different wavelengths can be easily realized for optimal sum frequency mixing. Besides, this configuration can overcome several disadvantages of the previously used configurations, and its photon density product integral of the two different wavelengths is about one order larger than the previous ones.


Acta Physica Sinica. 1999 48(4): 667-672. Published 1999-02-05 ]]>

Based on the rate equations of the Q-Switch simultaneous dual wavelength laser (SDWL) of Nd∶YAlO3 (Nd∶YAP), we have developed a new configuration of the cavity by adjusting the ratio of the cavity lengths for lasers with different wavelengths according to their emission cross sections. Therefore the competition ability and the net gain for the two different wavelengths will be equal at any time and anywhere in the laser rod, and the optimal spatial and temporal overlap of the different wavelengths can be easily realized for optimal sum frequency mixing. Besides, this configuration can overcome several disadvantages of the previously used configurations, and its photon density product integral of the two different wavelengths is about one order larger than the previous ones.


Acta Physica Sinica. 1999 48(4): 667-672. Published 1999-02-05 ]]>
1999-02-20T00:00:00+00:00 Personal use only, all commercial or other reuse prohibited Acta Physica Sinica. 1999 48(4): 667-672. article doi:10.7498/aps.48.667 10.7498/aps.48.667 Acta Physica Sinica 48 4 1999-02-05 //m.suprmerch.com/en/article/doi/10.7498/aps.48.667 667-672
<![CDATA[THEORETICAL ANALYSIS OF NONDEGENERATE FOUR-WAVE MIXING IN SEMICONDUCTOR LASER AMPLIFIERS]]> //m.suprmerch.com/en/article/doi/10.7498/aps.48.673

Theoretical analysis and numerical solution of several physical mechanisms on nondegenerate four-wave mixing(NDFWM) in semiconductor laser amplifiers are presented. Starting from the general carrier rate equation, density-matrix equations and nonlinear wave equations, considering the effects of carrier-density pulsations, carrier heating, and spectral-hole burning, we obtained three sets of nonlinear coupled wave equations, and compared the contributions of the three different physical mechanisms to the NDFWM. We also investigated the effect of linewidth enhancement factor on the conversion efficiency of the NDFWM in semiconductor laser amplifiers.


Acta Physica Sinica. 1999 48(4): 673-684. Published 1999-02-05 ]]>

Theoretical analysis and numerical solution of several physical mechanisms on nondegenerate four-wave mixing(NDFWM) in semiconductor laser amplifiers are presented. Starting from the general carrier rate equation, density-matrix equations and nonlinear wave equations, considering the effects of carrier-density pulsations, carrier heating, and spectral-hole burning, we obtained three sets of nonlinear coupled wave equations, and compared the contributions of the three different physical mechanisms to the NDFWM. We also investigated the effect of linewidth enhancement factor on the conversion efficiency of the NDFWM in semiconductor laser amplifiers.


Acta Physica Sinica. 1999 48(4): 673-684. Published 1999-02-05 ]]>
1999-02-20T00:00:00+00:00 Personal use only, all commercial or other reuse prohibited Acta Physica Sinica. 1999 48(4): 673-684. article doi:10.7498/aps.48.673 10.7498/aps.48.673 Acta Physica Sinica 48 4 1999-02-05 //m.suprmerch.com/en/article/doi/10.7498/aps.48.673 673-684
<![CDATA[MULTI-VARIABLE FEED-BACK CONTROL OF PLASMA CURRENT AND HORIZONTAL POSITION IN HT-7 SUPER-CONDUCTIVE TOKAMAK]]> //m.suprmerch.com/en/article/doi/10.7498/aps.48.685

In the analysis of HT-7 superconductive tokamak which consists of iron core, thick copper shell and multi-coupling coils system, the electromagnetic parameters are linearized by a novel method; the copper shell is replaced by an equivalent pair of coils in series-opposing; and the multi-coupling is compensated by an intermediate state variable. As a result, the plasma control equation can be set up and solved more simply and easily. The feed-back control system has been designed and rather good results were obtained in experiment. This feed-back control system has high response speed, less computing time and is easy to carry out.


Acta Physica Sinica. 1999 48(4): 685-691. Published 1999-02-05 ]]>

In the analysis of HT-7 superconductive tokamak which consists of iron core, thick copper shell and multi-coupling coils system, the electromagnetic parameters are linearized by a novel method; the copper shell is replaced by an equivalent pair of coils in series-opposing; and the multi-coupling is compensated by an intermediate state variable. As a result, the plasma control equation can be set up and solved more simply and easily. The feed-back control system has been designed and rather good results were obtained in experiment. This feed-back control system has high response speed, less computing time and is easy to carry out.


Acta Physica Sinica. 1999 48(4): 685-691. Published 1999-02-05 ]]>
1999-02-20T00:00:00+00:00 Personal use only, all commercial or other reuse prohibited Acta Physica Sinica. 1999 48(4): 685-691. article doi:10.7498/aps.48.685 10.7498/aps.48.685 Acta Physica Sinica 48 4 1999-02-05 //m.suprmerch.com/en/article/doi/10.7498/aps.48.685 685-691
<![CDATA[INTERNAL FRICTION BEHAVIOR OF THE STANDARD ANELASTIC SOLIDS IN LOW FREQUENCY INTERNAL FRICTION MEASUREMENT]]> //m.suprmerch.com/en/article/doi/10.7498/aps.48.692

Internal friction behavior of the standard anelastic solid has been described by τσ (the relaxation time at constant stress) and τε (the relaxation time at constant strain) of a three-parameter mechanical model. The effect of the inertia member in a vibration system on the internal friction values measured is not avoidable in a forced vibration experiment. When the measured internal friction values of a material are larger and the measuring frequency and resonant frequency of the vibration system are comparable to each other, the effect of the inertia member of the vibration system cannot be neglected.


Acta Physica Sinica. 1999 48(4): 692-698. Published 1999-02-05 ]]>

Internal friction behavior of the standard anelastic solid has been described by τσ (the relaxation time at constant stress) and τε (the relaxation time at constant strain) of a three-parameter mechanical model. The effect of the inertia member in a vibration system on the internal friction values measured is not avoidable in a forced vibration experiment. When the measured internal friction values of a material are larger and the measuring frequency and resonant frequency of the vibration system are comparable to each other, the effect of the inertia member of the vibration system cannot be neglected.


Acta Physica Sinica. 1999 48(4): 692-698. Published 1999-02-05 ]]>
1999-02-20T00:00:00+00:00 Personal use only, all commercial or other reuse prohibited Acta Physica Sinica. 1999 48(4): 692-698. article doi:10.7498/aps.48.692 10.7498/aps.48.692 Acta Physica Sinica 48 4 1999-02-05 //m.suprmerch.com/en/article/doi/10.7498/aps.48.692 692-698
<![CDATA[THE ORBITAL SYMMETRY OF CARBON MONOXIDE ON Cs-PRECOVERED Ru(1010) SURFACE]]> //m.suprmerch.com/en/article/doi/10.7498/aps.48.699

The molecular orbits of CO are rearranged under the strong influence of coadsorbed Cs atoms.The peak for CO on clean Ru(1010) surface,at 7.5eV BE attributed to the 5σ and 1π orbits,is split into two peaks with one at 6.3eV BE and the other at 7.8eV BE.The former peak shows an anti-symmetry character about the plane parallel to the crystallographic direction in the surface.


Acta Physica Sinica. 1999 48(4): 699-703. Published 1999-02-05 ]]>

The molecular orbits of CO are rearranged under the strong influence of coadsorbed Cs atoms.The peak for CO on clean Ru(1010) surface,at 7.5eV BE attributed to the 5σ and 1π orbits,is split into two peaks with one at 6.3eV BE and the other at 7.8eV BE.The former peak shows an anti-symmetry character about the plane parallel to the crystallographic direction in the surface.


Acta Physica Sinica. 1999 48(4): 699-703. Published 1999-02-05 ]]>
1999-02-20T00:00:00+00:00 Personal use only, all commercial or other reuse prohibited Acta Physica Sinica. 1999 48(4): 699-703. article doi:10.7498/aps.48.699 10.7498/aps.48.699 Acta Physica Sinica 48 4 1999-02-05 //m.suprmerch.com/en/article/doi/10.7498/aps.48.699 699-703
<![CDATA[TWO-DIMENSIONAL BISOLITON STATE IN THE ANISOTROPIC SQUARE CRYSTAL LATTICES]]> //m.suprmerch.com/en/article/doi/10.7498/aps.48.704

By considering the anisotropy in the quasi-two-dimensional Cu—O plane for the cuprate compound,on the basis of the two-dimensional bisoliton model estabished,the nonlinear local coupling efects caused by the interactions between electrons and phonons in the strongly anisotropic Cu—O plane are investiged.The formation of bisoliton and its bound states are discussed.The periodic bisoliton solution is given in the form of conoidal elliptic integral.The pairing energy for the two quasi-particles,the effective mass and the stability of the bisoliton are analysed in terms of the anisotropy.


Acta Physica Sinica. 1999 48(4): 704-712. Published 1999-02-05 ]]>

By considering the anisotropy in the quasi-two-dimensional Cu—O plane for the cuprate compound,on the basis of the two-dimensional bisoliton model estabished,the nonlinear local coupling efects caused by the interactions between electrons and phonons in the strongly anisotropic Cu—O plane are investiged.The formation of bisoliton and its bound states are discussed.The periodic bisoliton solution is given in the form of conoidal elliptic integral.The pairing energy for the two quasi-particles,the effective mass and the stability of the bisoliton are analysed in terms of the anisotropy.


Acta Physica Sinica. 1999 48(4): 704-712. Published 1999-02-05 ]]>
1999-02-20T00:00:00+00:00 Personal use only, all commercial or other reuse prohibited Acta Physica Sinica. 1999 48(4): 704-712. article doi:10.7498/aps.48.704 10.7498/aps.48.704 Acta Physica Sinica 48 4 1999-02-05 //m.suprmerch.com/en/article/doi/10.7498/aps.48.704 704-712
<![CDATA[A PRIMARY MODEL INVESTIGATION OF ORGANIC FERROMAGNETS]]> //m.suprmerch.com/en/article/doi/10.7498/aps.48.713

By using a simple tight-binding model,we study the magnetic properties of the substituted polyacetylene with lateral radicals R*.It includes the effects of π electron hopping between the alternate radicals and associated carbons on the bond order wave along the polyacetylene chain,the formation of charge density wave,and the effects of next-nearest-neighbor hoppings and electronic interactions.Our results are compared with and used to understand the ab initio calculations on the organic ferromagnet(C3H3)n,substituted polyacetylene with lateral radical R* as the organic segment CH2.


Acta Physica Sinica. 1999 48(4): 713-720. Published 1999-02-05 ]]>

By using a simple tight-binding model,we study the magnetic properties of the substituted polyacetylene with lateral radicals R*.It includes the effects of π electron hopping between the alternate radicals and associated carbons on the bond order wave along the polyacetylene chain,the formation of charge density wave,and the effects of next-nearest-neighbor hoppings and electronic interactions.Our results are compared with and used to understand the ab initio calculations on the organic ferromagnet(C3H3)n,substituted polyacetylene with lateral radical R* as the organic segment CH2.


Acta Physica Sinica. 1999 48(4): 713-720. Published 1999-02-05 ]]>
1999-02-20T00:00:00+00:00 Personal use only, all commercial or other reuse prohibited Acta Physica Sinica. 1999 48(4): 713-720. article doi:10.7498/aps.48.713 10.7498/aps.48.713 Acta Physica Sinica 48 4 1999-02-05 //m.suprmerch.com/en/article/doi/10.7498/aps.48.713 713-720
<![CDATA[DIELECTRIC SPECTROSCOPY INVESTIGATION ON POLAR PHASE TRANSITIONS]]> //m.suprmerch.com/en/article/doi/10.7498/aps.48.721

By using frequency and time domain dielectric spectroscopy, the polar phase transitions of (Ba1-xSrx)TiO3 ceramics have been studied. Compared with the phase transitions of a ferroelectric crystal, the motion of space charges in ceramic has been obtained as well as lattice softening, excitation of screen charges and motion of ferroelectric domains. Slow effect, which is contributed by ferroelectric domains and space charges, can affect the accurate measurement by frequency domain method. In this paper we describe this influence and explain some experimental results. The reciprocal of frequency domain dielectric constant has a linear softening in the transition of primary structure, but has a parabolic type softening in that of high structure.


Acta Physica Sinica. 1999 48(4): 721-728. Published 1999-02-05 ]]>

By using frequency and time domain dielectric spectroscopy, the polar phase transitions of (Ba1-xSrx)TiO3 ceramics have been studied. Compared with the phase transitions of a ferroelectric crystal, the motion of space charges in ceramic has been obtained as well as lattice softening, excitation of screen charges and motion of ferroelectric domains. Slow effect, which is contributed by ferroelectric domains and space charges, can affect the accurate measurement by frequency domain method. In this paper we describe this influence and explain some experimental results. The reciprocal of frequency domain dielectric constant has a linear softening in the transition of primary structure, but has a parabolic type softening in that of high structure.


Acta Physica Sinica. 1999 48(4): 721-728. Published 1999-02-05 ]]>
1999-02-20T00:00:00+00:00 Personal use only, all commercial or other reuse prohibited Acta Physica Sinica. 1999 48(4): 721-728. article doi:10.7498/aps.48.721 10.7498/aps.48.721 Acta Physica Sinica 48 4 1999-02-05 //m.suprmerch.com/en/article/doi/10.7498/aps.48.721 721-728
<![CDATA[EFFECTS OF DIELECTRIC CONFINEMENT ON EXCITIONIC STATES IN CdSe QUANTUM DOT]]> //m.suprmerch.com/en/article/doi/10.7498/aps.48.729

According to the relationship of Wang and Zunger between the declectric constants and the radius of a CdSe quantum dot (QD),we use the variational method to calculate the binding energy and ground state energy of an exciton in the QD.Compared with the previouse calculations,the present result shows that the binding energy increases while its ground state energy becomes lower and it is close to the experimental value.


Acta Physica Sinica. 1999 48(4): 729-734. Published 1999-02-05 ]]>

According to the relationship of Wang and Zunger between the declectric constants and the radius of a CdSe quantum dot (QD),we use the variational method to calculate the binding energy and ground state energy of an exciton in the QD.Compared with the previouse calculations,the present result shows that the binding energy increases while its ground state energy becomes lower and it is close to the experimental value.


Acta Physica Sinica. 1999 48(4): 729-734. Published 1999-02-05 ]]>
1999-02-20T00:00:00+00:00 Personal use only, all commercial or other reuse prohibited Acta Physica Sinica. 1999 48(4): 729-734. article doi:10.7498/aps.48.729 10.7498/aps.48.729 Acta Physica Sinica 48 4 1999-02-05 //m.suprmerch.com/en/article/doi/10.7498/aps.48.729 729-734
<![CDATA[THE COUPLING OF OPTICAL AND SIZE POLYDISPERSITIES BY DYNAMIC LIGHT SCATTERING]]> //m.suprmerch.com/en/article/doi/10.7498/aps.48.735

We study the detection theory of polydispersities for dilute suspension of optical and size polydisperse spherical particles, for which the Rayleigh-Gans-Debye (RGD) approximation is valid.To develop the theory a concentric core-shell hard sphere model is adopted,in which particles possess a continuous variation in the core size and shell thickness,the latter is directly proportional to the radius of core,thus giving rise to a distribution in the particle refractive indices.We assume the shell thickness to be L=αR,where αm(K) is derived. We analyse the dependence of the average scattered intensity I(q) and the effective diffusion coefficient De(q) which is obtained from the first cumulant measured by dynamic light scattering in the case that the refractive index of the solvent and that of the shell are matched,i.e.,nm=ns, on the scattering vector q.A linear relation between the extreme point of the effective diffusion coefficient and the polydispersity δ is obtained, which gives a method to detect the small size polydispersities of a disperse system.


Acta Physica Sinica. 1999 48(4): 735-743. Published 1999-02-05 ]]>

We study the detection theory of polydispersities for dilute suspension of optical and size polydisperse spherical particles, for which the Rayleigh-Gans-Debye (RGD) approximation is valid.To develop the theory a concentric core-shell hard sphere model is adopted,in which particles possess a continuous variation in the core size and shell thickness,the latter is directly proportional to the radius of core,thus giving rise to a distribution in the particle refractive indices.We assume the shell thickness to be L=αR,where αm(K) is derived. We analyse the dependence of the average scattered intensity I(q) and the effective diffusion coefficient De(q) which is obtained from the first cumulant measured by dynamic light scattering in the case that the refractive index of the solvent and that of the shell are matched,i.e.,nm=ns, on the scattering vector q.A linear relation between the extreme point of the effective diffusion coefficient and the polydispersity δ is obtained, which gives a method to detect the small size polydispersities of a disperse system.


Acta Physica Sinica. 1999 48(4): 735-743. Published 1999-02-05 ]]>
1999-02-20T00:00:00+00:00 Personal use only, all commercial or other reuse prohibited Acta Physica Sinica. 1999 48(4): 735-743. article doi:10.7498/aps.48.735 10.7498/aps.48.735 Acta Physica Sinica 48 4 1999-02-05 //m.suprmerch.com/en/article/doi/10.7498/aps.48.735 735-743
<![CDATA[EXCITON DYNAMICS IN SELF-ORGANIZED InAs/GaAs QUANTUM DOTS]]> //m.suprmerch.com/en/article/doi/10.7498/aps.48.744

Using a newly-developed population mixing technique we have studied the exciton dynamics in self-organized InAs/GaAs quantum dots (QDs).It is found that the exciton lifetime in self-organized InAs/GaAs QDs is around 1ns, almost independent of InAs layer thickness.The temperature dependence of the exciton lifetime varies from sample to sample,but no obvious experimental evidence was found that the lifetime is related to the δ-function of density of states in QDs.We have also found that the population mixing technique can be used to directly reveal the band-filling effect in the excited states of the QDs.


Acta Physica Sinica. 1999 48(4): 744-750. Published 1999-02-05 ]]>

Using a newly-developed population mixing technique we have studied the exciton dynamics in self-organized InAs/GaAs quantum dots (QDs).It is found that the exciton lifetime in self-organized InAs/GaAs QDs is around 1ns, almost independent of InAs layer thickness.The temperature dependence of the exciton lifetime varies from sample to sample,but no obvious experimental evidence was found that the lifetime is related to the δ-function of density of states in QDs.We have also found that the population mixing technique can be used to directly reveal the band-filling effect in the excited states of the QDs.


Acta Physica Sinica. 1999 48(4): 744-750. Published 1999-02-05 ]]>
1999-02-20T00:00:00+00:00 Personal use only, all commercial or other reuse prohibited Acta Physica Sinica. 1999 48(4): 744-750. article doi:10.7498/aps.48.744 10.7498/aps.48.744 Acta Physica Sinica 48 4 1999-02-05 //m.suprmerch.com/en/article/doi/10.7498/aps.48.744 744-750
<![CDATA[COUPLED-SOLITON FOR THE HELIX CHAIN MODEL OF THE ALPHA-HELIX PROTEIN]]> //m.suprmerch.com/en/article/doi/10.7498/aps.48.751

The coupled soliton solutions of nonlinear Schrdinger equations for describing the alpha-helix protein are obtained, and their physical meaning is discussed.


Acta Physica Sinica. 1999 48(4): 751-756. Published 1999-02-05 ]]>

The coupled soliton solutions of nonlinear Schrdinger equations for describing the alpha-helix protein are obtained, and their physical meaning is discussed.


Acta Physica Sinica. 1999 48(4): 751-756. Published 1999-02-05 ]]>
1999-02-20T00:00:00+00:00 Personal use only, all commercial or other reuse prohibited Acta Physica Sinica. 1999 48(4): 751-756. article doi:10.7498/aps.48.751 10.7498/aps.48.751 Acta Physica Sinica 48 4 1999-02-05 //m.suprmerch.com/en/article/doi/10.7498/aps.48.751 751-756
<![CDATA[STEP MAGNETIZATION AND COLOSSAL MAGNETORESIS-TANCE IN SPIN GLASS MANGANITES La0.67Ca0.33(Mn,Fe)O3]]> //m.suprmerch.com/en/article/doi/10.7498/aps.48.757

The step magnetization is observed in spin glass manganites La0.67Ca0.33(Mn,Fe)O3, and the colossal magnetoresistance larger than 104%(ΔR/RH) is obtained near the critical field.The micro-origin of the novel step magnetism is attributed to the melting of antiferromagnetic clusters in the applied magnetic field.


Acta Physica Sinica. 1999 48(4): 757-762. Published 1999-02-05 ]]>

The step magnetization is observed in spin glass manganites La0.67Ca0.33(Mn,Fe)O3, and the colossal magnetoresistance larger than 104%(ΔR/RH) is obtained near the critical field.The micro-origin of the novel step magnetism is attributed to the melting of antiferromagnetic clusters in the applied magnetic field.


Acta Physica Sinica. 1999 48(4): 757-762. Published 1999-02-05 ]]>
1999-02-20T00:00:00+00:00 Personal use only, all commercial or other reuse prohibited Acta Physica Sinica. 1999 48(4): 757-762. article doi:10.7498/aps.48.757 10.7498/aps.48.757 Acta Physica Sinica 48 4 1999-02-05 //m.suprmerch.com/en/article/doi/10.7498/aps.48.757 757-762
<![CDATA[TUNNELING GIANT MAGNETORESISTANCE IN Fe-Al2O3 GRANULAR FILMS]]> //m.suprmerch.com/en/article/doi/10.7498/aps.48.763

Tunneling giant magnetoresistance(TGMR) in Fe-Al2O3 granular films which were prepared by co-sputtering have been reported.MR ratio of the film with Fe volume fractions fV≈0.45 takes a maximum of 4.4% at room temperature when a magnetic field of 1T was applied parallel to the film plane,accompanying huge specific electrical resistivities of the order of 105 μΩ·cm.Field dependence of the MR is well described by the form proportional to the square of the magnetization of the film.Temperature dependence of the MR ratio of the film has also been investigated.The MR exhibits strong temperature dependence.The MR below 50K remarkably increases with decreasing temperature resulting in MR=14.9% and 26% at 20 and 4.2K,respectively.The anomalous increase of the MR at low temperature seems to arise from the successive onset of higher-order processes of spin-dependent tunneling between large granules through intervening small ones with strong Coulomb blockade.


Acta Physica Sinica. 1999 48(4): 763-768. Published 1999-02-05 ]]>

Tunneling giant magnetoresistance(TGMR) in Fe-Al2O3 granular films which were prepared by co-sputtering have been reported.MR ratio of the film with Fe volume fractions fV≈0.45 takes a maximum of 4.4% at room temperature when a magnetic field of 1T was applied parallel to the film plane,accompanying huge specific electrical resistivities of the order of 105 μΩ·cm.Field dependence of the MR is well described by the form proportional to the square of the magnetization of the film.Temperature dependence of the MR ratio of the film has also been investigated.The MR exhibits strong temperature dependence.The MR below 50K remarkably increases with decreasing temperature resulting in MR=14.9% and 26% at 20 and 4.2K,respectively.The anomalous increase of the MR at low temperature seems to arise from the successive onset of higher-order processes of spin-dependent tunneling between large granules through intervening small ones with strong Coulomb blockade.


Acta Physica Sinica. 1999 48(4): 763-768. Published 1999-02-05 ]]>
1999-02-20T00:00:00+00:00 Personal use only, all commercial or other reuse prohibited Acta Physica Sinica. 1999 48(4): 763-768. article doi:10.7498/aps.48.763 10.7498/aps.48.763 Acta Physica Sinica 48 4 1999-02-05 //m.suprmerch.com/en/article/doi/10.7498/aps.48.763 763-768