Zhong Haiyang

Reddish Orange Long-Lasting Phosphorescence in KY3F10:Sm3+ for X-Ray or Cathode Ray Tubes

We report a reddish orange long-lasting phosphor of KY3F10:Sm3+ synthesized by a solid-state reaction for applications in x-ray or cathode-ray tubes. The spectrum contains a group of reddish orange emission lines originating from 4G5/2 → 6HJ transitions of Sm3+. The Judd—Ofelt theory is introduced to analyze the optical transitions of the Sm3+ ions. Moreover, phosphorescence characteristics are discussed. The energy charging and release processes of the phosphor are measured and the phosphorescence decay time with 10% of initial intensity is about 40.7 seconds. The order of kinetics and the activation energy are obtained according to the thermoluminescence curve. The phosphorescence mechanism is proposed based on structural analysis and thermoluminescence glow curve measurement.

The Influence of Strong Laser Fields on the Interaction between Fast B+3 Clusters and Plasmas

The influence of a high-intensity laser field on the inelastic interactions between a swift B+3 cluster ion and a plasma target is studied by means of the linearized Vlasov-Poisson theory. Excitations of the plasma are described by the classical plasma dielectric function. In the presence of the laser field, the general expressions for the induced potential in the target and the interaction force among the ions within the cluster are derived. Based on the numerical solution of the equations of motion for the constituent ions, the Coulomb explosion patterns and the clusters energy losses are discussed for a range of laser parameters.

On the fluorescence enhancement mechanism of Er3+ in germanate glass containing silver particles

The spectral properties of trivalent erbium ions (Er3+) are systematically studied in a melt-quenched germanate glass (60 GeO2-20PbO-10BaO-10K2O-0.1Ag2O) containing silver (Ag) particles. Thermal treatment of the material leads to the precipitation of Ag particles as observed by transmission electron microscopy and confirmed by absorption spectrum for the obvious surface plasmon resonance peak of Ag particles. The fluorescence from Er3+ in the 10-min-annealed sample with Ag particles is found to be 4.2 times enhanced compared with the unannealed sample excited by 488-nm Ar+ laser. A comparison is made between a spectral study performed on the unannealed Er3+-doped sample and the one annealed for 20 min. The data of absorption cross section and Judd—Ofelt intensity parameters show the agreement between the two samples no matter whether there are Ag particles, indicating that the introduction of Ag particles by post-heat treatment has no effect on the crystal field environment of Er3+ ions. The fluorescence enhancement is attributed to the surface plasmon oscillations of Ag particles in germanate glass.

Remote Generation of Entanglement for Individual Atoms via Optical Fibres

The generation of atomic entanglement is discussed in a system that atoms are trapped in separate cavities which are connected via optical fibres. Two distant atoms can be projected to Bell-state by synchronized turning off of the local laser fields and then performing a single quantum measurement by a distant controller. The distinct advantage of this scheme is that it works in a regime where Δ ≈ κ g, which makes the scheme insensitive to cavity strong leakage. Moreover, the fidelity is not affected by atomic spontaneous emission.The generation of atomic entanglement is discussed in a syst em that atoms are trapped in separate cavities which are connected via optical fibers. Two distant atoms can be projected to Bell-state by synchronized turning off the local laser fields and then performing a single quantum me asur ment by a distant controller. The distinct advantage of this scheme is that it works in a regime that ∆ ≈ κ ≫ g, which makes the scheme insensitive to cavity strong leakage. Moreover, the fidelity is not a ffected by atomic spontaneous emission.

Preparation of Gd2O2S:Yb,Ho Phosphor via Thermolysis of Sulfur-Contained (Gd,Yb,Ho)[S2CN(C4H8)]3 Phen Complexes

A novel handy single-source precursor method is adopted to prepare Gd2O2S:Yb,Ho up-conversion phosphors. Pure Gd2O2S:Yb0.06Ho0.02 phosphors are prepared via thermolysis of the air-stable ternary solid complexes RE[S2CN(C4H8)]3phen (RE=Gd, Yb, Ho) in a nitrogen atmosphere with certain amount of oxygen at 600–1100°C. The as-prepared Gd2O2S:Yb0.06Ho0.02 exhibits a strong green up-conversion luminescence under 980 nm IR excitation. The intensity of the green emission component is 37.4 and 53.4 times more than that of the red and NIR emissions, respectively. It is indicated that the material is of excellent color purity. Under an IR excitation density of 34.75 mW/mm2 with a laser beam diameter of 1 mm, the material exhibits an up-conversion luminescence brightness of 43.68 Cd/m2.

A U(4) QCD Model Using Generalized Yang?Mills Theory

Generalized Yang–Mills theory has a covariant derivative which contains both vector and pseudoscalar gauge bosons. Based on this theory, we construct a U(4) strong interaction model. By using this U(4) generalized Yang–Mills model, we obtain that mesons can be realized as the colorless pseudoscalar gauge bosons. We also obtain a gauge potential solution which can be used to explain the asymptotic behavior and color confinement.

Using New Material to Analyze Doppler-shift Arising From Change of the Solar-angle

From simple theory of Chapman, we deduce a formula to calculate Doppler-shift arising from change of the solar-angle. We compare the result of theory with new material-Doppler records of BPM and JJY ,and analyze the reasons of producing difference.

An Approach to the Dyadic Green's Functions for a Rectangular Chirowaveguide

A novel method of formulating eigenfunction expansion of the dyadic Greens function in lossless, recipcocal and homogeneous chirowaveguides is given,using this method, the non-divergence vector potential equation can be transformed into that similar to achiral media,the corresponding wavefield decomposition is used to obtain the vector wave function. A specific application to the analytic solution of electromagnetic wave propagation in a rectangular chirowaveguide illustrates the method.

On Dyadic Green's Function of a Field Vector

A method of deriving directly the irrotational and non-divergence component for the spectral domain dyadic Greens function of a field vector is given. Helmholtz theorem and the irrotational and non-divergence splitting of dyadic Dirac delta function are used to obtain the irrotational and non-divergence dyadic Greens function, a specific application to the electromagnetic wave field in chiral media illustrates the method.

An approach to the dyadic Green's functions for a parallel-plate chirowaveguide

A method of the eigenfunction expansion of electromagnetic dyadic Greens functions in a parallel-plate chirowaveguide is given in this paper. By using this method, we can not only obtain the vector wave equations equivalent to that for chiral media but also similar to that for achiral media, the corresponding chiral eigenmodes in parallel-plate waveguides can take a similar form as the conventional achiral eigenmodes also, and then the dyadic Greens functions in a parallel-plate chirowaveguide can take a similar form as the conventional achiral dyadic Greens functions