Graphene is a newly discovered material that possesses unique electronic properties. It is a two-dimensional singlelayered sheet in which the electrons are free and quasi-relativistic. These properties may open a door for many new electronic applications. In this paper we proposed a flat 2-dimensional circular graphene-semiconductor quantum dot. We have carried out theoretical studies including deriving the Dirac equation for the electrons inside the graphene-semiconductor quantum dot and solving the equation. We have established the energy structure as a function of the rotational quantum number and the size (radius) of the dot. The energy gap between the energy levels can be tuned with the radius of the quantum dot. It could be useful for quantum computation and single electron device application.

Abstract:
China’s higher education has been going through a period of rapid expansion in undergraduate population,and this means a much heavier demand on teaching resources such as laboratories, experiments, teaching staff,etc., which cannot possibly be made available all of a sudden.To deal with this situation, we found virtual reality (VR) technology very helpful. Virtual reality (VR) has found many applications in education; and the resources of virtual education such as virtual campus, virtual laboratory etc. are used more and more widely, especially in the field of higher education. But so far virtual campus was mainly regarded as a means of image exhibition, and virtual laboratories were no more than 2D display of experimental processes and equipments. To make better use of these resources, this paper puts forward the concept of networked virtual experiment systems based on virtual campus by combining the virtual laboratory and virtual campus with the technique of LAN (Local area network), and establishes its theoretical model. Finally, a networked virtual experiment system based on virtual campus is developed using VRML and 3DSMAX. Networked virtual experiment system based on virtual campus has a promising future for various applications in higher education.

Abstract:
We suggest that electron-laser interactions can give rise to resonance phenomena as the intensity varies. A new QED perturbation theory is developed, in which the coupling between an electron and the second quantized laser mode is treated nonperturbatively. We predict, for example, the above-threshold ionization rate shows peaks at intensities with integer ponderomotive parameter. Such quantum resonance effects may be exploited to calibrate laser intensities in appropriate range.

Abstract:
The ordinary Schrodinger equation with minimal coupling for a nonrelativistic electron interacting with a single-mode photon field is not satisfied by the nonrelativistic limit of the exact solutions to the corresponding Dirac equation. A Schrodinger-like equation valid for arbitrary photon intensity is derived from the Dirac equation without the weak-field assumption. The "eigenvalue" in the new equation is an operator in a Cartan subalgebra. An approximation consistent with the nonrelativistic energy level derived from its relativistic value replaces the "eigenvalue" operator by an ordinary number, recovering the ordinary Schrodinger eigenvalue equation used in the formal scattering formalism. The Schrodinger-like equation for the multimode case is also presented.

Abstract:
Using techniques of complex analysis in an algebraic approach, we solve the wave equation for a two-level atom interacting with a monochromatic light field exactly. A closed-form expression for the quasi-energies is obtained, which shows that the Bloch-Siegert shift is always finite, regardless of whether the original or the shifted level spacing is an integral multiple of the driving frequency, $\omega$. We also find that the wave functions, though finite when the original level spacing is an integral multiple of $\omega$, become divergent when the intensity-dependent shifted energy spacing is an integral multiple of the photon energy. This result provides, for the first time in the literature, an ab-initio theoretical explanation for the occurrence of the Freeman resonances observed in above-threshold ionization experiments.

Abstract:
In the title compound, C7H7NO4S, the nitro group is twisted by 10.2 (5) ° out of the plane of the benzene ring. Inversion-related molecules are linked by non-classical C—H...O hydrogen bonds into dimers featuring an R22(10) motif.

Abstract:
In the title coordination polymer, {[NaZn(C11H8NO6)(H2O)3]·2H2O}n, the Zn atom is coordinated in a distorted tetrahedral environment by three carboxylate O atoms from two (4-carboxylatophenylimino)diacetate ligands and one water molecule; the Na atom is in an distorted octahedral coordination environment formed by four carboxylate O atoms from three (4-carboxylatophenylimino)diacetate ligands and two water molecules. The Zn atoms and Na atoms are linked by (4-carboxylatophenylimino)diacetate ligands into a three-dimensional framework; the uncoordinated water molecules fill the voids of the skeleton and stabilize it by O—H...O hydrogen bonds.

Abstract:
An operator-valued quantum phase space formula is constructed. The phase space formula of Quantum Mechanics provides a natural link between first and second quantization, thus contributing to the understanding of quantization problem. By the combination of quantization and hamiltonization of dynamics, a quantization hierarchy is introduced, beyond the framework of first and second quantization and generalizing the standard quantum theory. We apply our quantization method to quantum many-body system and propose an eclectic model, in which the dimension of Hilbert space does not scale exponentially with the number of particles due to the locality of interaction, and the evolution is a constrained Hamiltonian dynamics.

Abstract:
Quantum field theory is mostly known as the most advanced and well-developed theory in physics, which combines quantum mechanics and special relativity consistently. In this work, we study the spinless quantum field theory, namely the Klein-Gordon equation, and we find that there exists a Dirac form of this equation which predicts the existence of spinless fermion. For its understanding, we start from the interpretation of quantum field based on the concept of quantum scope, we also extract new meanings of wave-particle duality and quantum statistics. The existence of spinless fermion is consistent with spin-statistics theorem and also supersymmetry, and it leads to several new kinds of interactions among elementary particles. Our work contributes to the study of spinless quantum field theory and could have implications for the case of higher spin.

Abstract:
Quantum channels, which are completely positive and trace preserving mappings, can alter the dimension of a system; e.g., a quantum channel from a qubit to a qutrit. We study the convex set properties of dimension-altering quantum channels, and particularly the channel decomposition problem in terms of convex sum of extreme channels. We provide various quantum circuit representations of extreme and generalized extreme channels, which can be employed in an optimization to approximately decompose an arbitrary channel. Numerical simulations of low-dimensional channels are performed to demonstrate our channel decomposition scheme.