According to generalized linear quantum transformation theory, we give the exact expression of the evolution operator, wave function and expectation value of observable quantity for one-dimensional quantum oscillator with a variable frequency: ω(t)={\displaystyle\frac{ω_{0}_{1+βt}}(ω_{0}, β>0).

By analyzing the Einstein's equations for the static sphere, we find that there exists a non-singular static configuration whose radius can approach its corresponding horizon size arbitrarily.

This paper presents a four-dimensional nonlinear dynamical system. By the numerical simulation the hyperchaotic attractor, Lyapunov exponents and Lyapunov dimension are obtained, also it is confirmed that hyperchaos can be driven in the system described by the equation. The control action of the periodic perturbation on the autonomous hyperchaotic system is studied, and a control rule is obtained which indicates the relationship of the control action and the frequency characteristics after degeneration of the system. Finaly the circuit implementation of the dynamical system is given.

In this paper we investigate the distance between density operators in multiphoton processes. We study the distances between the time-evolved states of the atom, of the field, and of the total system and their respective reference states, compare them with the atomic inversion as well as the purity of the field, disclose their corresponding relations in various multiphoton processes. The physical interpretations are given by using a fully quantized Bloch equation in the two-photon process.

Intensity dependence of the total effective trap density N_{eff} is studied theoretically for the two-centre and the three-charge-state photorefractive crystals. The results show that N_{eff} always increases with increasing intensity in three-charge-state crystals, whereas it has more complicated behaviors in two-centre crystals. When S_{D}γ_{T}/S_{T}γ_{D} is small, N_{eff} increases and tends to saturate with increasing intensity for both type-A and type-B two-centre crystals. When S_{D}γ_{T}/S_{T}γ_{D} is large, N_{eff} increases to a maximum and then decreases a little for type-A crystals and decreases greatly for type-B crystals. The different intensity dependences of N_{eff} in the two types of crystals come from their different level structures.

CONDENSED MATTER: STRUCTURAL, MECHANICAL, AND THERMAL PROPERTIES

The stripe-shaped domain (SSD) structure was prepared in the initial ferroelectric liquid crystal (FLC) alignment without the application of an external electric field, which was realized by the aligning layer modification through the doping of tin tetra-2, 4-dimethyl phenoxy phthalocyanine (SnPc) into the rubbed polyimide films. Atomic force microscopy was used to investigate the alignment films and the corresponding aligning ability was evaluated through the pre-tilt angle measurement. The memory capability and the contrast ratio of thus aligned SSFLC cells have been enhanced and improved with the appearance of the SSD structure. The electrically controlled 64×64 FLC spatial light modulator was fabricated using the improved ligning method, which proves valuable for the practical device fabrication.

CONDENSED MATTER: ELECTRONIC STRUCTURE, ELECTRICAL, MAGNETIC, AND OPTICAL PROPERTIES

The mobility of a two-dimensional electron gas in GaAs-AlGaAs heterojunction is re-computed through solving numerically the balance equation. The peculiarity of the present study lies in that a new expression for the distribution function and the renormalized phonon frequency are used in the computation. Compared with those reported by previous authors, our result shows better agreement with the experimental data.

La_{1-x} Sr_{x}CrO_{3} nanoparticles were prepared by the sol-gel method. The sintering temperature of the samples could be decreased to about 400 K. The crystal structures of La_{1-x} Sr_{x}CrO_{3} at room temperature are all of the othorhombic perovskite GdFeO_{3}-type (x≤0.4). And the electrical conductivity increases with x, but when x>0.3 it decreases. The higher the sintering temperature, the better the electrical conductivity, because the grain size of the examples increases with increasing sintering temperature.

By using the combination of the first-nearest neighbor tight-binding model sp^{3}s^{*} and Green function method in the frame of the scattering theory, we studied the electronic structure of ZnTe/CdSe(100) heterojunction with cation layers interchange across ZnSe-like or CdTe-like interface, and presented the interface band structures and wavevector-resolved interface layer densities of states. By comparing with the electronic states of ideal interfaces, we analyzed the nature and origins of all interface states, and discussed the influence of atom layers interchange on interface electronic structure.

Hole-overdoped Bi_{2}Sr_{2-x}La_{x}CuO_{6+δ} single crystals with two coexistent superconducting transitions have been intensively studied by measuring the dc magnetic susceptibility. It is found that the coexistence of these two phases cannot be attributed to any chemical or vortex dynamical effect but to some intrinsic driving force, such as the electronic-driven phase separation. Furthermore, the upper critical fields of the two phases behave in a rather different way; that is, one of them shows a "normal H_{c2} behavior" which can be described by the critical fluctuation theory, while the other exhibits an "anomalous H_{c2} behavior" and can be well explained by a recent theory based on an assumption of a Josephson-coupling origin, indicating a strong evidence of Josephson-coupling origin for the upward curvature of the so-called H_{c2} in high T_{c} superconductors.

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