Noise-Mediated Generalized Synchronization

We investigate a drive-response system by considering the impacts of noise on generalized synchronization （GS）. It is found that a small amount of noise can turn the system from desynchronization to the GS state in the resonant case no matter how noise is injected into the system. In the non-resonant case, noise with intensity in a certain range is helpful in building GS only when the noise is injected to the driving system. The mechanism behind the observed phenomena is discussed.     

Determination of Astrophysical 13N（p,γ）^14O S-factors from the Asymptotic Normalization Coefficient of ^14C→^13C ＋ n

The angular distribution of the ^13C（d,p）^14C reaction is reanalysed using the Johnson-Soper approach. The squared asymptotic normalization coefficient （ANC） of virtual decay ^14 C →^13 C^14＋ n is then derived to be 21.4±5.0 fm^-1. The squared ANC and spectroscopic factor （SF） of ^14O→^13N ＋p are extracted to be 30.4± 7.1 fm^-1 and 1.94 ± 0.45, respectively. The astrophysical S-factors and reaction rates of ^13N（p, γ）140 are determined from the ANC of ^14O → ^13N ＋ P using the R-matrix approach.     

Mechanism of Proton-Induced Reactions on Targets ^16O, ^27Al, ^56Fe, ^112Cd, ^184W and ^208Pb At Ep = 800 MeV

We investigate the 800 MeV proton-induced spallation reactions on various targets by the improved quantum molecular dynamics （ImQMD05） model incorporated with a statistical decay model （SDM）. The influence of the nucleon-nucleon effective interaction on proton induced spallation reactions is studied by using different Skyrme interactions. It is found that the low energy part of the neutron double differential cross sections （DDCS）, which is mainly contributed from the decay of the excited residue, is influenced by the effective nucleon-nucleon interaction strongly., while the high energy part of neutron DDCS is influenced weakly. Among the Skyrme interactions used in the calculations, the calculation results with SkP give the best agreement with the experimental data.     

Structural Transition of Gd2O3：Eu Induced by High Pressure

The structural transition of bulk and uano-size Gd2O3：Eu are studied by high pressure energy disperse x-ray diffraction （XRD） and high pressure photoluminescence. Our results show that in spite of different size of Gd2O3 particles, the cubic structure turns into a possible hexagonal one above 13.4 GPa. When the pressure is released, the sample reverses to the monoclinic structure. No cubic structure presents in the released samples. That is to say, the compression and relaxation of the sample leads to the cubic Gd2O3：Eu then turns into the monoclinic one.     

A Reflected Terahertz-Emission Microscopy

A novel reflected terahertz-emission microscopy is proposed and developed for improving the spatial resolution of THz imaging. When attaching a bow-tie antenna directly onto a thin generation crystal, the reflected THz waves can be collected and detected by a photoconductive antenna, and the spatial resolution is decided by the diameter of focused pump beam. In this way, the detected resolution can be largely improved and tunable. The configuration and characteristics of this microscopy are described in detail.     

Flip-Chip GaN-Based Light-Emitting Diodes with Mesh-Contact Electrodes

GaN-based light-emitting diodes （LEDs） with mesh-contact electrodes have been developed. The p-type ohmic contact layer is composed of oxidized Ni/Au mesh and NiO overlay （20A）. An Ag （3000A） omni-directional reflector covers the p-type contact. The n-type contact is a Ti/AI planar film with a 10-μm-width Ti/AI stripe. The Ti/AI stripe surrounds the centre of LED mesa. With a 20-mA current injection, the light output power of GaN-based LEDs with mesh-contact electrodes is 23% higher than that of the conventional LEDs.     

Properties of All-Solid Square-Lattice Photonic Bandgap Fibres

Properties of all-solid square-lattice photonic bandgap fibres are studied for the first time to the best of our knowledge. Using the plane-wave expansion method and finite element method, we investigate the mode, effective area, confinement loss and dispersion of such fibres. The simulation results demonstrate that the proposed effective mode area of all-solid square-lattice photonic bandgap fibres is 1.25 times larger than triangular-lattice ones and the confinement loss of the fibres is no more than 0.1 dB/m within the bandgap.     

商丘师范学院物理与信息工程系

商丘师范学院物理与信息工程系（简称物信系）在同类同级高校中是一个师资、教学和科研能力较强的理工大系。目前，物信系有教职工45人，其中教授8人、副教授16人、校外兼职教授2人，博士7人、硕士12人。现有物理学（本科）、电子信息工程（本科）、应用电子技术（专科）三个专业，在校学生900多人。新增应用物理学（本科）专业将于2007年开始招生。有两个校级重点学科，一个校级名牌专业，两门省级精品课程，三门校级精品课程。近三年来，物信系教师共完成和承担科研项目46项，其中国家级2项、省部级12项；发表教学科研论文260余篇，其中被SCI和EI收录54篇，出版专著和教材8部；获得和申请国家专3117项。     

物理学难题选登Ⅳ

习题 问题103＊ 有一张桌子高1m，在其表面中间有一个洞．有一根长1m的细的金项链自然地盘绕着放在洞口，如图中所示：     

Periodic-soliton solutions of the （2＋1）-dimensional Kadomtsev-Petviashvili equation

2N line-soliton solutions of the （2＋1）-dimensional Kadomtsev-Petviashvili equation can be presented by resorting to the Hirota bilinear method. By extending the real parameters into complex parameters, this paper obtains N periodic-soliton solutions of the （2＋1）-dimensional Kadomtsev-Petviashvili equation from the 2N line-soliton solutions.