The amplitude-dependent ac susceptibility of high-temperature superconductors is shown to obey some empirical scaling relations. We try to analyze this behavior by extending a dc nonlinear response function of mixed s...The amplitude-dependent ac susceptibility of high-temperature superconductors is shown to obey some empirical scaling relations. We try to analyze this behavior by extending a dc nonlinear response function of mixed state to the ac cases. The derived equations for critical current and ac susceptibility x(T) agree with the scaling relations of experimental data.展开更多
Considering two beams propagate in semiconductor crystal, this paper discusses the polarization dependence of pump beam-induced intensity attenuation of probe beam due to two-photon absorption （TPA）. Numerical calcu...Considering two beams propagate in semiconductor crystal, this paper discusses the polarization dependence of pump beam-induced intensity attenuation of probe beam due to two-photon absorption （TPA）. Numerical calculation and experimental measurement demonstrate that TPA coefficient is polarization dependent. For homogeneous materials, probe beam attenuation arises from the imaginary part of diagonal and off-diagonal components of third-order nonlinear susceptibilities.展开更多
We study the colour-locked twin-noisy-field correlation effects in the fifth-order nonlinear susceptibility of ultrafast polarization beats in a cascade four-level system. More importantly, the fifth-order phase-sensi...We study the colour-locked twin-noisy-field correlation effects in the fifth-order nonlinear susceptibility of ultrafast polarization beats in a cascade four-level system. More importantly, the fifth-order phase-sensitive heterodyne detection of ultrafast polarization beats has been exploited. The fifth-order nonlinear optical response can be controlled and modified through the colour-locked correlation of twin noisy fields. Thus, this method with the phase dispersion information is a good way to measure the real and imaginary parts of the fifth-order nonlinear susceptibility.展开更多
The density matrix approach has been employed to investigate the opticalnonlinear polarization in a single semiconductor quantum dot(QD). Electron states are considered tobe confined within a quantum dot with infinite...The density matrix approach has been employed to investigate the opticalnonlinear polarization in a single semiconductor quantum dot(QD). Electron states are considered tobe confined within a quantum dot with infinite potential barriers. It is shown, by numericalcalculation, that the third-order nonlinear optical susceptibilities for a typical Si quantum dot isdependent on the quantum size of the quantum dot and the frequency of incident light.展开更多
We formulate and systematically study a deterministic compartmental model of Hepatitis B.This model has some important and novel features compared with the well-known basic model in the literature.Specifically,it take...We formulate and systematically study a deterministic compartmental model of Hepatitis B.This model has some important and novel features compared with the well-known basic model in the literature.Specifically,it takes into account the differential susceptibility that follows the vaccine formulation employing three-doses schedule.It points up the HbeAg status of carriers,their levels of viral replication,the fact that treatment being not curative is recommended only to a small proportion of chronic carriers,and finally the fact that only inactive carriers are able to recover from disease.The model has simple dynamical behavior which has a globally asymptotically stable disease-free equilibrium when the basic reproduction number R0≤1 and an endemic equilibrium when R0>1.By the use of Lyapunov functions,when it exists,we prove the global asymptotic stability of the endemic equilibrium under some conditions.Using data from Tokombere,a rural area in Cameroon,numerical simulations are performed.These numerical simulations first confirm analytical results,second they suggest that a policy based on treatment could not significantly impact the course of the infection.Third,they show as it is well known that vaccination is a very effective measure to control the infection.Furthermore,they show that neonatal vaccination influences more the course of infection than mass vaccination strategy.Nevertheless,they picture how much loss between consecutive doses of vaccine could be harmful.Finally,it is suggested that for a Sub-saharan African rural area,two-thirds of expected incidence of Hepatitis B virus infection and one third of expected prevalence of chronic carriers could be averted by 2030 if the birth dose vaccination becomes systematic and if mass vaccination rate increases to up 10%.展开更多
The effects of the nonlinear polarization in a partially stripped plasma on the parameter processes of a strong laser are discussed. The nonlinear mode coupling equations of stimulated Raman scattering (SRS) are deriv...The effects of the nonlinear polarization in a partially stripped plasma on the parameter processes of a strong laser are discussed. The nonlinear mode coupling equations of stimulated Raman scattering (SRS) are derived. The linear instability growth rates of SRS and stimulated Brillouin scattering (SBS) are given. When the pump wave intensity I0 > 1017 W/cm2, the third order susceptibility associated with bound electrons will reduce the SRS and SBS linear growth rate enormous1y. In addition, the nonlinear susceptibility can affect the nonlinear evolution of SRS and SBS significantly.展开更多
A perturbative approach is used to study the AC response of nonlinear composite media, which obey a current-field relation of the form with components having nonlinear response at finite frequencies. For a sinusoidal...A perturbative approach is used to study the AC response of nonlinear composite media, which obey a current-field relation of the form with components having nonlinear response at finite frequencies. For a sinusoidal applied field, we extend the local potential in terms of sinusoidal components at fundamental frequency and high-order harmonic frequencies to treat the nonlinear composites. For nonlinear composite media with a low concentrations of spherical inclusions, we give the formulae of the nonlinear effective AC susceptibility at the third harmonic frequency.展开更多
As a representative transition metal oxide,cupric oxide(CuO)has attracted a lot of interest in miscel-laneous fields.In the present work,the prominent third-order nonlinear optical(NLO)features of CuO nanosheets were ...As a representative transition metal oxide,cupric oxide(CuO)has attracted a lot of interest in miscel-laneous fields.In the present work,the prominent third-order nonlinear optical(NLO)features of CuO nanosheets were demonstrated via the typical Z-scan technique at 1 m m.The open-aperture(OA)Z-scan measurements at different intensities clearly showed that CuO nanosheets possessed the saturable ab-sorption(SA),reverse saturable absorption(RSA)and optical limiting behaviors.The closed-aperture(CA)Z-scan technology was implanted to investigate the nonlinear refractive index and the third-order nonlinear susceptibility.In virtue of the strong nonlinear optical absorption properties of CuO nano-sheets,a stable all-solid-state mode-locked laser with the as-prepared CuO nanosheets as saturable absorber at 1.06 m m was realized for the first time.Our work confirmed that CuO nanosheets exhibited outstanding NLO properties,which might stimulate the development in ultrafast photonics and nonlinear optics.展开更多
基金This work was supported by the Ministry of Science and Technology of China(Grant No.NKBRSG-G 1999064602)the National Natural Science Foundation of China(Grant Nos.10174003 and 50377040).
文摘The amplitude-dependent ac susceptibility of high-temperature superconductors is shown to obey some empirical scaling relations. We try to analyze this behavior by extending a dc nonlinear response function of mixed state to the ac cases. The derived equations for critical current and ac susceptibility x(T) agree with the scaling relations of experimental data.
文摘Considering two beams propagate in semiconductor crystal, this paper discusses the polarization dependence of pump beam-induced intensity attenuation of probe beam due to two-photon absorption （TPA）. Numerical calculation and experimental measurement demonstrate that TPA coefficient is polarization dependent. For homogeneous materials, probe beam attenuation arises from the imaginary part of diagonal and off-diagonal components of third-order nonlinear susceptibilities.
基金Project supported by the National Natural Science Foundation of China(Grant Nos60308002and60678005)the Foundation for the Author of National Excellent Doctoral Dissertation of China(Grant No200339)+2 种基金the Foundation for Key Program of Ministry of Education,China(Grant No105156)the Fok Ying-Tong Education Foundation for Young Teachers in the Higher Education Institutions of China(Grant No101061)the Specialized Research Fund for the Doctoral Program of Higher Education of China(Grant No20050698017)
文摘We study the colour-locked twin-noisy-field correlation effects in the fifth-order nonlinear susceptibility of ultrafast polarization beats in a cascade four-level system. More importantly, the fifth-order phase-sensitive heterodyne detection of ultrafast polarization beats has been exploited. The fifth-order nonlinear optical response can be controlled and modified through the colour-locked correlation of twin noisy fields. Thus, this method with the phase dispersion information is a good way to measure the real and imaginary parts of the fifth-order nonlinear susceptibility.
基金Supported by the Committee of Science and Tech nology of Wuhan(1320017010121)
文摘The density matrix approach has been employed to investigate the opticalnonlinear polarization in a single semiconductor quantum dot(QD). Electron states are considered tobe confined within a quantum dot with infinite potential barriers. It is shown, by numericalcalculation, that the third-order nonlinear optical susceptibilities for a typical Si quantum dot isdependent on the quantum size of the quantum dot and the frequency of incident light.
文摘We formulate and systematically study a deterministic compartmental model of Hepatitis B.This model has some important and novel features compared with the well-known basic model in the literature.Specifically,it takes into account the differential susceptibility that follows the vaccine formulation employing three-doses schedule.It points up the HbeAg status of carriers,their levels of viral replication,the fact that treatment being not curative is recommended only to a small proportion of chronic carriers,and finally the fact that only inactive carriers are able to recover from disease.The model has simple dynamical behavior which has a globally asymptotically stable disease-free equilibrium when the basic reproduction number R0≤1 and an endemic equilibrium when R0>1.By the use of Lyapunov functions,when it exists,we prove the global asymptotic stability of the endemic equilibrium under some conditions.Using data from Tokombere,a rural area in Cameroon,numerical simulations are performed.These numerical simulations first confirm analytical results,second they suggest that a policy based on treatment could not significantly impact the course of the infection.Third,they show as it is well known that vaccination is a very effective measure to control the infection.Furthermore,they show that neonatal vaccination influences more the course of infection than mass vaccination strategy.Nevertheless,they picture how much loss between consecutive doses of vaccine could be harmful.Finally,it is suggested that for a Sub-saharan African rural area,two-thirds of expected incidence of Hepatitis B virus infection and one third of expected prevalence of chronic carriers could be averted by 2030 if the birth dose vaccination becomes systematic and if mass vaccination rate increases to up 10%.
基金Supported by the National High-Tech ICF(Inertial Confinement Fusion)Committee in China。
文摘The effects of the nonlinear polarization in a partially stripped plasma on the parameter processes of a strong laser are discussed. The nonlinear mode coupling equations of stimulated Raman scattering (SRS) are derived. The linear instability growth rates of SRS and stimulated Brillouin scattering (SBS) are given. When the pump wave intensity I0 > 1017 W/cm2, the third order susceptibility associated with bound electrons will reduce the SRS and SBS linear growth rate enormous1y. In addition, the nonlinear susceptibility can affect the nonlinear evolution of SRS and SBS significantly.
文摘A perturbative approach is used to study the AC response of nonlinear composite media, which obey a current-field relation of the form with components having nonlinear response at finite frequencies. For a sinusoidal applied field, we extend the local potential in terms of sinusoidal components at fundamental frequency and high-order harmonic frequencies to treat the nonlinear composites. For nonlinear composite media with a low concentrations of spherical inclusions, we give the formulae of the nonlinear effective AC susceptibility at the third harmonic frequency.
基金The National Natural Science Foundation of China(12004213,21872084).
文摘As a representative transition metal oxide,cupric oxide(CuO)has attracted a lot of interest in miscel-laneous fields.In the present work,the prominent third-order nonlinear optical(NLO)features of CuO nanosheets were demonstrated via the typical Z-scan technique at 1 m m.The open-aperture(OA)Z-scan measurements at different intensities clearly showed that CuO nanosheets possessed the saturable ab-sorption(SA),reverse saturable absorption(RSA)and optical limiting behaviors.The closed-aperture(CA)Z-scan technology was implanted to investigate the nonlinear refractive index and the third-order nonlinear susceptibility.In virtue of the strong nonlinear optical absorption properties of CuO nano-sheets,a stable all-solid-state mode-locked laser with the as-prepared CuO nanosheets as saturable absorber at 1.06 m m was realized for the first time.Our work confirmed that CuO nanosheets exhibited outstanding NLO properties,which might stimulate the development in ultrafast photonics and nonlinear optics.
