Based on the general theory of time-dependent quantum transformation, we use the 'time evolutionoperator' method to solve the single-mode time-dependent oscillator.
The two-dimensional hydrogen with a linear potential in a magnetic field is solved by two different methods.Furthermore the connection between the model and an anharmonic oscillator is investigated by methods of KStra...The two-dimensional hydrogen with a linear potential in a magnetic field is solved by two different methods.Furthermore the connection between the model and an anharmonic oscillator is investigated by methods of KStransformation.展开更多
The pyrolysis of pyridine （5.26% pyridine in argon） was performed with tunable synchrotron vacuum ultraviolet photoionization and molecular-beam mass spectrometry technique at the temperature range of 1255-1765 K at...The pyrolysis of pyridine （5.26% pyridine in argon） was performed with tunable synchrotron vacuum ultraviolet photoionization and molecular-beam mass spectrometry technique at the temperature range of 1255-1765 K at 267 Pa. About 20 products and intermediates, containing major species H2, HCN, C2H2, C5H3N, C4H2, and C3H3N, were identified by near-threshold measurements of photoionization mass spectra and their mole fractions vs. temperatures were estimated. The major reaction pathways are analyzed based on the experimental observations.展开更多
Si(111)electrode has been widely used in electrochemical and photoelectrochemical studies.The potential dependent measurements of the second harmonic generation(SHG)were performed to study Si(111)electrode interface.A...Si(111)electrode has been widely used in electrochemical and photoelectrochemical studies.The potential dependent measurements of the second harmonic generation(SHG)were performed to study Si(111)electrode interface.At different azimuthal angles of the Si(111)and under different polarization combinations,the curve of the intensity of SHG with extern potential has a different form of line or parabola.Quantitative analysis showed that these differences in the potential-dependence can be explained by the isotropic and anisotropic contribution of the Si(111)electrode.The change in the isotropic and anisotropic contribution of the Si(111)electrode may be attributed to the increase in the doping concentration of Si(111)electrodes.展开更多
The authors have investigated the pH and ionic strength response of self-assembled layers formed by adsorption of amphiphilic weak polyelectrolytes. Using the SFA （Surface Forces Apparatus） the authors measured forc...The authors have investigated the pH and ionic strength response of self-assembled layers formed by adsorption of amphiphilic weak polyelectrolytes. Using the SFA （Surface Forces Apparatus） the authors measured force-distance profiles of poly （isoprene）-poly （acrylic acid） block copolymers adsorbed on mica. Also by Atomic Force Microscopy the authors captured single polyelectrolyte molecule adsorbed on a surface. The effect of salt concentration （Cs） and pH upon the height of the brush layers was explored mainly by measuring the forces between two adsorbed polyelectrolyte brushes. At pH = 4 our results are in good agreement with the scaling prediction L0 ∝Cs-1/3 Changing the pH from 4 to 10 causes a remarkable swelling of the polymer layer, but only a weak dependence on salt concentration was detected at the higher pH. This can be attributed to the degree of dissociation, which depends on the local pH value. At low pH the polyelectrolyte chains have a low charge density, while on increasing the pH the degree of dissociation rises, and the increased charge density is followed by swelling of the adsorbed layer. The local concentration of ions in the brush is now greater than that of pH = 4 and approximately equivalent to 0.3 M. So the swelling is only weakly dependent on salt concentration in the range 0.01-1.0 M. The results demonstrate the tunable nature of such self-assembled polyelectroiyte brushes whose height and range of interactions, can be systematically controlled by adjusting the pH and ionic strength of the medium.展开更多
We present three families of one-soliton solutions for （2＋1）-dimensional Gross-Pitaevskii equation with both time-dependent scattering length and gain or loss in a harmonic trap. Then we investigate the dynamics of...We present three families of one-soliton solutions for （2＋1）-dimensional Gross-Pitaevskii equation with both time-dependent scattering length and gain or loss in a harmonic trap. Then we investigate the dynamics of these solitons in Bose-Einstein condensate8 （BECs） by some selected control functions. Our results show that the intensities of these solitons first increase rapidly to the condensation peak, then decay very slowly to the background; thus the lifetime of a bright soliton, a train of bright solitons and a dark soliton in BECs can be all greatly extended. Our results offer a useful method for observing matter-wave solitons in BECs in future experiments.展开更多
The new method proposed recently by Friedberg, Lee, and Zhao is extended to obtain an analytic expansion for the ground-state wavefunction of a time-dependent strong-coupling Schroedinger equation. Two different types...The new method proposed recently by Friedberg, Lee, and Zhao is extended to obtain an analytic expansion for the ground-state wavefunction of a time-dependent strong-coupling Schroedinger equation. Two different types of the time-dependent harmonic oscillators are considered as examples for application of the time-dependent expansion. It is show that the time-dependent strong-coupling expansion is applicable to the time-dependent harmonic oscillators with a slowly varying time-dependent parameter.展开更多
The quantum discord was introduced by Ollivier,Zurek,Henderson,and Vedral as an indicator of the degree of quantumness of mixed states.In this paper,we provide a decomposition condition for quantum discord.Moreover,we...The quantum discord was introduced by Ollivier,Zurek,Henderson,and Vedral as an indicator of the degree of quantumness of mixed states.In this paper,we provide a decomposition condition for quantum discord.Moreover,we show that under the condition,the quantum correlations between the quantum systems can be captured completely by the entanglement measure.Finally,we present examples of our conclusions.展开更多
To understand the operation principle of the modular multilevel converter(MMC)deeply,it is necessary to study the harmonic characteristics of the MMC theoretically.Besides,the analytical harmonic formulas of the MMC a...To understand the operation principle of the modular multilevel converter(MMC)deeply,it is necessary to study the harmonic characteristics of the MMC theoretically.Besides,the analytical harmonic formulas of the MMC are useful in designing the main circuit,reducing the losses and improving the waveform quality.Based on the average switching function and the Fourier series harmonic analysis,this paper deduces the analytical expressions for such electrical quantities as the arm voltage,the arm current,the capacitor voltage,the capacitor current and the circulating current of the MMC.Finally,a digital model of a 21-level MMC-HVDC system is realized in PSCAD/EMTDC.The results of the analytical expressions coincide with the simulation results,which verify the effectiveness and feasibility of the proposed analytical expressions.展开更多
We completely characterize commuting dual Toeplitz operators with bounded harmonic symbols on the harmonic Bergman space of the unit disk. We show that for harmonic ■ and ψ, S■Sψ= SψS■ on(L2h)⊥if and only if ■...We completely characterize commuting dual Toeplitz operators with bounded harmonic symbols on the harmonic Bergman space of the unit disk. We show that for harmonic ■ and ψ, S■Sψ= SψS■ on(L2h)⊥if and only if ■ and ψ satisfy one of the following conditions:(1) Both ■ and ψ are analytic on D.(2) Both ■ and ψ are anti-analytic on D.(3) There exist complex constants α and β, not both 0, such that ■ = αψ + β.Furthermore, we give the necessary and sufficient conditions for S■Sψ= S■ψ.展开更多
For a pure non-markovian dephasing model we derive analytic expressions of coherent information,quantum discord,and entanglement.We find that for the cases of the initial Werner states,the dynamical behavior of cohere...For a pure non-markovian dephasing model we derive analytic expressions of coherent information,quantum discord,and entanglement.We find that for the cases of the initial Werner states,the dynamical behavior of coherent information is similar to that of quantum discord but different from that of entanglement.Coherent information,as well as quantum discord,can reveal the quantum correlations in some mixed-states,in which the entanglement is zero.展开更多
We have given a straightforward method to solve the problem of noncentral anharmonic oscillator in three dimensions. The relative propagator is presented by means of path integrals in spherical coordinates. By making ...We have given a straightforward method to solve the problem of noncentral anharmonic oscillator in three dimensions. The relative propagator is presented by means of path integrals in spherical coordinates. By making an adequate change of time we are able to separate the angular motion from the radial one. The relative propagator is then exactly calculated. The energy spectrum and the corresponding wave functions are obtained.展开更多
Both the homotopy analysis method and Galerkin spectral method are applied to find the analytical solutions of the two-dimensional and time-independent Gross-Pitaevskii equation, a nonlinear Schrodinger equation used ...Both the homotopy analysis method and Galerkin spectral method are applied to find the analytical solutions of the two-dimensional and time-independent Gross-Pitaevskii equation, a nonlinear Schrodinger equation used in describing the system of Bose-Einstein condensates trapped in a harmonic potential. The approximate analytical solutions are obtained successfully. Comparisons between the analytical solutions and the numerical solutions have been made. The results indicate that they are agreement very well with each other when the atomic interaction is not too strong.展开更多
In this paper, we investigate excited characteristic of the weakly interacting quasi-one-dimensional （11）） and quasi-two-dimensional （2D） Bose-Einstein condensation （BEC） in harmonic potential trap. The energ3,...In this paper, we investigate excited characteristic of the weakly interacting quasi-one-dimensional （11）） and quasi-two-dimensional （2D） Bose-Einstein condensation （BEC） in harmonic potential trap. The energ3, spectrum and the analytical expression of the sound velocity are obtained and analyzed. Compared with 3-Dimensional homogeneous Bose-condensed gas occasion, the sound velocity of 21） Bose-Einstein condensation in harmonic potential trap is smaller.展开更多
We propose improved ring shaped like potential of the form,V（r,θ）=V（r）＋（h^2/2M r^2）[（βsin^2θ＋γcos^2θ＋2λ）/sinθcosθ]^2 and its exact solutions are presented via the Nikiforov–Uvarov method.The angle ...We propose improved ring shaped like potential of the form,V（r,θ）=V（r）＋（h^2/2M r^2）[（βsin^2θ＋γcos^2θ＋2λ）/sinθcosθ]^2 and its exact solutions are presented via the Nikiforov–Uvarov method.The angle dependent part V（θ）=（h^2/2M r^2）[（βsin^2θ＋γcos^2θ＋λ）/sinθcosθ]^2,which is reported for the first time embodied the novel angle dependent（NAD）potential and harmonic novel angle dependent potential（HNAD）as special cases.We discuss in detail the effects of the improved ring shaped like potential on the radial parts of the spherical harmonic and Coulomb potentials.展开更多
Quantum correlations among parts of a composite quantum system are a fundamental resource for several applications in quantum information. In general, quantum discord can measure quantum correlations. In that way,we i...Quantum correlations among parts of a composite quantum system are a fundamental resource for several applications in quantum information. In general, quantum discord can measure quantum correlations. In that way,we investigate the quantum discord of the two-qubit system constructed from the Yang–Baxter Equation. The density matrix of this system is generated through the unitary Yang–Baxter matrix R. The analytical expression and numerical result of quantum discord and geometric measure of quantum discord are obtained for the Yang–Baxter system. These results show that quantum discord and geometric measure of quantum discord are only connect with the parameter θ,which is the important spectral parameter in Yang–Baxter equation.展开更多
Slowing down velocity and controlling time delay of optical pulses in fiber have many potential applications in optical com-munication systems,and a number of theoretical and experimental studies have been done.In thi...Slowing down velocity and controlling time delay of optical pulses in fiber have many potential applications in optical com-munication systems,and a number of theoretical and experimental studies have been done.In this paper,the transmission spectrum and reflective spectrum of active fiber Bragg grating(FBG)couplers are studied,and the analytic expressions of dispersion and time delay are obtained.By changing the detuning and gain coefficient,different dispersions and time delays in active fiber Bragg grating coupler are obtained.The results show that different detunings and gain coefficients can result in various time delays,and thus tunable time delay could be achieved by changing signal frequency or gain coefficient.展开更多
文摘Based on the general theory of time-dependent quantum transformation, we use the 'time evolutionoperator' method to solve the single-mode time-dependent oscillator.
基金Supported in part by National Natural Science Foundation of China under Grant Nos.10605013 and 10975075 the Fundamental Research Funds for the Central Universities
文摘The two-dimensional hydrogen with a linear potential in a magnetic field is solved by two different methods.Furthermore the connection between the model and an anharmonic oscillator is investigated by methods of KStransformation.
基金Ⅴ. ACKNOWLEDGMENTS This work was supported by the Chinese Academy of Sciences, the Natural Science Foundation of China （No.20533040）, the National Basic Research Program of China （973） （No.2007CB815204m）, and the Ministry of Science and Technology of China （No.2007DFA61310）.
文摘The pyrolysis of pyridine （5.26% pyridine in argon） was performed with tunable synchrotron vacuum ultraviolet photoionization and molecular-beam mass spectrometry technique at the temperature range of 1255-1765 K at 267 Pa. About 20 products and intermediates, containing major species H2, HCN, C2H2, C5H3N, C4H2, and C3H3N, were identified by near-threshold measurements of photoionization mass spectra and their mole fractions vs. temperatures were estimated. The major reaction pathways are analyzed based on the experimental observations.
基金supported by the National Natural Science Foundation of China(No.21673251,No.21773258,No.21873104,and No.91856121)the Chinese Academy of Sciences(No.JKYYQ20180014)。
文摘Si(111)electrode has been widely used in electrochemical and photoelectrochemical studies.The potential dependent measurements of the second harmonic generation(SHG)were performed to study Si(111)electrode interface.At different azimuthal angles of the Si(111)and under different polarization combinations,the curve of the intensity of SHG with extern potential has a different form of line or parabola.Quantitative analysis showed that these differences in the potential-dependence can be explained by the isotropic and anisotropic contribution of the Si(111)electrode.The change in the isotropic and anisotropic contribution of the Si(111)electrode may be attributed to the increase in the doping concentration of Si(111)electrodes.
文摘The authors have investigated the pH and ionic strength response of self-assembled layers formed by adsorption of amphiphilic weak polyelectrolytes. Using the SFA （Surface Forces Apparatus） the authors measured force-distance profiles of poly （isoprene）-poly （acrylic acid） block copolymers adsorbed on mica. Also by Atomic Force Microscopy the authors captured single polyelectrolyte molecule adsorbed on a surface. The effect of salt concentration （Cs） and pH upon the height of the brush layers was explored mainly by measuring the forces between two adsorbed polyelectrolyte brushes. At pH = 4 our results are in good agreement with the scaling prediction L0 ∝Cs-1/3 Changing the pH from 4 to 10 causes a remarkable swelling of the polymer layer, but only a weak dependence on salt concentration was detected at the higher pH. This can be attributed to the degree of dissociation, which depends on the local pH value. At low pH the polyelectrolyte chains have a low charge density, while on increasing the pH the degree of dissociation rises, and the increased charge density is followed by swelling of the adsorbed layer. The local concentration of ions in the brush is now greater than that of pH = 4 and approximately equivalent to 0.3 M. So the swelling is only weakly dependent on salt concentration in the range 0.01-1.0 M. The results demonstrate the tunable nature of such self-assembled polyelectroiyte brushes whose height and range of interactions, can be systematically controlled by adjusting the pH and ionic strength of the medium.
基金Supported by NSFC under Grant Nos. 11041003, 10735030, 10874235, 10934010, 60978019, the NKBRSFC under Grant Nos. 2009CB930701, 2010CB922904, and 2011CB921500Zhejiang Provincial NSF under Grant No. Y6090592+1 种基金Ningbo Natural Science Foundation under Grant Nos. 2010A610095, 2010A610103, and 2009B21003K.C. Wong Magna Fund in Ningbo University
文摘We present three families of one-soliton solutions for （2＋1）-dimensional Gross-Pitaevskii equation with both time-dependent scattering length and gain or loss in a harmonic trap. Then we investigate the dynamics of these solitons in Bose-Einstein condensate8 （BECs） by some selected control functions. Our results show that the intensities of these solitons first increase rapidly to the condensation peak, then decay very slowly to the background; thus the lifetime of a bright soliton, a train of bright solitons and a dark soliton in BECs can be all greatly extended. Our results offer a useful method for observing matter-wave solitons in BECs in future experiments.
基金Supported by the National Natural Science Foundation of China under Grant No.10905019the Program for Changjiang Scholars and Innovative Research Team in University(PCSIRT,No.IRT0964)the Construct Program of the National Key Discipline
文摘The new method proposed recently by Friedberg, Lee, and Zhao is extended to obtain an analytic expansion for the ground-state wavefunction of a time-dependent strong-coupling Schroedinger equation. Two different types of the time-dependent harmonic oscillators are considered as examples for application of the time-dependent expansion. It is show that the time-dependent strong-coupling expansion is applicable to the time-dependent harmonic oscillators with a slowly varying time-dependent parameter.
基金Supported by Research Fund,Kumoh National Institute of Technology
文摘The quantum discord was introduced by Ollivier,Zurek,Henderson,and Vedral as an indicator of the degree of quantumness of mixed states.In this paper,we provide a decomposition condition for quantum discord.Moreover,we show that under the condition,the quantum correlations between the quantum systems can be captured completely by the entanglement measure.Finally,we present examples of our conclusions.
基金supported by the National High Technology Research and Development Program of China("863" Project)(Grant No.2012AA050205)
文摘To understand the operation principle of the modular multilevel converter(MMC)deeply,it is necessary to study the harmonic characteristics of the MMC theoretically.Besides,the analytical harmonic formulas of the MMC are useful in designing the main circuit,reducing the losses and improving the waveform quality.Based on the average switching function and the Fourier series harmonic analysis,this paper deduces the analytical expressions for such electrical quantities as the arm voltage,the arm current,the capacitor voltage,the capacitor current and the circulating current of the MMC.Finally,a digital model of a 21-level MMC-HVDC system is realized in PSCAD/EMTDC.The results of the analytical expressions coincide with the simulation results,which verify the effectiveness and feasibility of the proposed analytical expressions.
基金supported by National Natural Science Foundation of China(Grant Nos.10971020 and 1127059)Research Fund for the Doctoral Program of Higher Education of China
文摘We completely characterize commuting dual Toeplitz operators with bounded harmonic symbols on the harmonic Bergman space of the unit disk. We show that for harmonic ■ and ψ, S■Sψ= SψS■ on(L2h)⊥if and only if ■ and ψ satisfy one of the following conditions:(1) Both ■ and ψ are analytic on D.(2) Both ■ and ψ are anti-analytic on D.(3) There exist complex constants α and β, not both 0, such that ■ = αψ + β.Furthermore, we give the necessary and sufficient conditions for S■Sψ= S■ψ.
基金Supported by National Science Foundation of China under Grant Nos. 11005008,10974016,and 11075013
文摘For a pure non-markovian dephasing model we derive analytic expressions of coherent information,quantum discord,and entanglement.We find that for the cases of the initial Werner states,the dynamical behavior of coherent information is similar to that of quantum discord but different from that of entanglement.Coherent information,as well as quantum discord,can reveal the quantum correlations in some mixed-states,in which the entanglement is zero.
文摘We have given a straightforward method to solve the problem of noncentral anharmonic oscillator in three dimensions. The relative propagator is presented by means of path integrals in spherical coordinates. By making an adequate change of time we are able to separate the angular motion from the radial one. The relative propagator is then exactly calculated. The energy spectrum and the corresponding wave functions are obtained.
基金Supported by the National Natural Science Foundation under Grant No. 11047010
文摘Both the homotopy analysis method and Galerkin spectral method are applied to find the analytical solutions of the two-dimensional and time-independent Gross-Pitaevskii equation, a nonlinear Schrodinger equation used in describing the system of Bose-Einstein condensates trapped in a harmonic potential. The approximate analytical solutions are obtained successfully. Comparisons between the analytical solutions and the numerical solutions have been made. The results indicate that they are agreement very well with each other when the atomic interaction is not too strong.
基金Supported by National Natural Science Foundation of China under Grant No.11275082
文摘In this paper, we investigate excited characteristic of the weakly interacting quasi-one-dimensional （11）） and quasi-two-dimensional （2D） Bose-Einstein condensation （BEC） in harmonic potential trap. The energ3, spectrum and the analytical expression of the sound velocity are obtained and analyzed. Compared with 3-Dimensional homogeneous Bose-condensed gas occasion, the sound velocity of 21） Bose-Einstein condensation in harmonic potential trap is smaller.
文摘We propose improved ring shaped like potential of the form,V（r,θ）=V（r）＋（h^2/2M r^2）[（βsin^2θ＋γcos^2θ＋2λ）/sinθcosθ]^2 and its exact solutions are presented via the Nikiforov–Uvarov method.The angle dependent part V（θ）=（h^2/2M r^2）[（βsin^2θ＋γcos^2θ＋λ）/sinθcosθ]^2,which is reported for the first time embodied the novel angle dependent（NAD）potential and harmonic novel angle dependent potential（HNAD）as special cases.We discuss in detail the effects of the improved ring shaped like potential on the radial parts of the spherical harmonic and Coulomb potentials.
基金Supported by the National Natural Science Foundation of China under Grant Nos. 11247260 and 11305020 and the CUST Foundation for Young Scholars under Grant No. XQNJJ-2011-03
文摘Quantum correlations among parts of a composite quantum system are a fundamental resource for several applications in quantum information. In general, quantum discord can measure quantum correlations. In that way,we investigate the quantum discord of the two-qubit system constructed from the Yang–Baxter Equation. The density matrix of this system is generated through the unitary Yang–Baxter matrix R. The analytical expression and numerical result of quantum discord and geometric measure of quantum discord are obtained for the Yang–Baxter system. These results show that quantum discord and geometric measure of quantum discord are only connect with the parameter θ,which is the important spectral parameter in Yang–Baxter equation.
基金supported by the National Natural Science Foundation of China(No.10704043)the Natural Science Foundation of Zhejiang Province(No.Y1110078)
文摘Slowing down velocity and controlling time delay of optical pulses in fiber have many potential applications in optical com-munication systems,and a number of theoretical and experimental studies have been done.In this paper,the transmission spectrum and reflective spectrum of active fiber Bragg grating(FBG)couplers are studied,and the analytic expressions of dispersion and time delay are obtained.By changing the detuning and gain coefficient,different dispersions and time delays in active fiber Bragg grating coupler are obtained.The results show that different detunings and gain coefficients can result in various time delays,and thus tunable time delay could be achieved by changing signal frequency or gain coefficient.
