In a two-dimensional quantum dot （QD） with parabolic confinement potential, we investigate pure dephasing due to deformation potential exciton-bulk longitudinal acoustic phonons （LAP） interaction for exciton qubit...In a two-dimensional quantum dot （QD） with parabolic confinement potential, we investigate pure dephasing due to deformation potential exciton-bulk longitudinal acoustic phonons （LAP） interaction for exciton qubits under the influence of external static electric and magnetic fields by adopting the full quantum-mechanical method of Kunihiro Kojima and Akihisa Tomita. The wave function is found and the dependence of the pure dephasing factor on the confinement length of the QD and time and temperature is discussed. We find the external electric and magnetic fields have important effects on pure dephasing of exciton qubits because exciton-LAP interaction increases, leading to more pure dephasing.展开更多
Osteoblasts of rat cultured in vitro were stimulated with pulsed 50 Hz electromagnetic field and basic fibroblast growth factor(bFGF).The MTT method,flow cytometry and histochemistry staining were used to detect cell ...Osteoblasts of rat cultured in vitro were stimulated with pulsed 50 Hz electromagnetic field and basic fibroblast growth factor(bFGF).The MTT method,flow cytometry and histochemistry staining were used to detect cell proliferation?cell cycle and alkaline phosphatase .The results indicated: after stimulated by 1 mT electromagnetic field,the cells are more abundant,have more S phase percentages,2 mT electromagnetic field have no evident effect on cells’growth;compared with electromagnetic field,the cells stimulated by bFGF are more abundant and have larger S phase ratios.Electromagnetic field and bFGF have no effect on cells,alkaline phosphatase.Therefore ,we concluded that electromagnetic field can enhance osteoblasts growth like some growth factor such as basic fibroblast growth factor,and the osteoblasts’,characteristics was not changed.展开更多
Two linear In this letter, we prove the following conclusions by introducing a function Fn（t）： （1） If a quantum system S with a time-dependent non-degenerate Hamiltonian H（t） is initially in the n-th eigenstate...Two linear In this letter, we prove the following conclusions by introducing a function Fn（t）： （1） If a quantum system S with a time-dependent non-degenerate Hamiltonian H（t） is initially in the n-th eigenstate of H（0）, then the state of the system at time t will remain in the n-th eigenstate of H（t） up to a multiplicative phase factor if and only if the values Fn（t） for all t are always on the circle centered at 1 with radius 1; （2） If a quantum system S with a time-dependent Hamiltonian H（t） is initially in the n-th eigenstate of H（0）, then the state of the system at time t will remain c-uniformly approximately in the n-th eigenstate of H（t） up to a multiplicative phase factor if and only if the values F,（t） for all t are always outside of the circle centered at 1 with radius 1-ε. Moreover, some quantitative sufficient conditions for the state of the system at time t to remain ε-uniformly approximately in the n-th eigenstate of H（t） up to a multiplicative phase factor are established. Lastly, our results are illustrated by a spin-half particle in a rotating magnetic field.展开更多
基金supported by National Natural Science Foundation of China under Grant No.10347004
文摘In a two-dimensional quantum dot （QD） with parabolic confinement potential, we investigate pure dephasing due to deformation potential exciton-bulk longitudinal acoustic phonons （LAP） interaction for exciton qubits under the influence of external static electric and magnetic fields by adopting the full quantum-mechanical method of Kunihiro Kojima and Akihisa Tomita. The wave function is found and the dependence of the pure dephasing factor on the confinement length of the QD and time and temperature is discussed. We find the external electric and magnetic fields have important effects on pure dephasing of exciton qubits because exciton-LAP interaction increases, leading to more pure dephasing.
基金This work Supported by National Natural Science Foundation( 10 172 0 93) and the10 th Five-Year PlanMedical Research Foun-dation of PL A( 0 1MA0 88)
文摘Osteoblasts of rat cultured in vitro were stimulated with pulsed 50 Hz electromagnetic field and basic fibroblast growth factor(bFGF).The MTT method,flow cytometry and histochemistry staining were used to detect cell proliferation?cell cycle and alkaline phosphatase .The results indicated: after stimulated by 1 mT electromagnetic field,the cells are more abundant,have more S phase percentages,2 mT electromagnetic field have no evident effect on cells’growth;compared with electromagnetic field,the cells stimulated by bFGF are more abundant and have larger S phase ratios.Electromagnetic field and bFGF have no effect on cells,alkaline phosphatase.Therefore ,we concluded that electromagnetic field can enhance osteoblasts growth like some growth factor such as basic fibroblast growth factor,and the osteoblasts’,characteristics was not changed.
基金supported by the National Natural Science Foundation of China(Grant No. 11171197)the IFGP of Shaanxi Normal University(Grant No. 2011CXB004)the FRF for the Central Universities(Grant No. GK201002006)
文摘Two linear In this letter, we prove the following conclusions by introducing a function Fn（t）： （1） If a quantum system S with a time-dependent non-degenerate Hamiltonian H（t） is initially in the n-th eigenstate of H（0）, then the state of the system at time t will remain in the n-th eigenstate of H（t） up to a multiplicative phase factor if and only if the values Fn（t） for all t are always on the circle centered at 1 with radius 1; （2） If a quantum system S with a time-dependent Hamiltonian H（t） is initially in the n-th eigenstate of H（0）, then the state of the system at time t will remain c-uniformly approximately in the n-th eigenstate of H（t） up to a multiplicative phase factor if and only if the values F,（t） for all t are always outside of the circle centered at 1 with radius 1-ε. Moreover, some quantitative sufficient conditions for the state of the system at time t to remain ε-uniformly approximately in the n-th eigenstate of H（t） up to a multiplicative phase factor are established. Lastly, our results are illustrated by a spin-half particle in a rotating magnetic field.
