Construction of One New 3D Zinc-organic Framework Based on D-（＋）-camphoric Acid and Bis（4-pyridylmethyl）piperazine

A new polymer [Zn2（cam）2（bpmp）]n 1 （H2cam = D-（＋）-camphoric acid, bpmp = bis（4-pyridylmethyl）piperazine） was synthesized under hydrothermal conditions. The compound crystallizes in the monoclinic system, space group P21/n with a = 12.305（9）, b = 12.945（9）, c = 13.619（10） A, β = 116.833（8）°, V= 1936（2）A3, Z = 4, Mr = 397.76, Dc= 1.365 Mg/m3,μ = 1.292 mm-1, F（000） = 832, the final R = 0.0578 and wR = 0.1678 for 2838 observed reflections with I 〉 2σ（I）. The compound presents a three-dimensional （3D） network extended by homochiral 2D layer and bpmp ligands. From the topology point of view, the structure could be described as a 3D 6-connected mab net with （44.610.8） topology. In addition, infrared spectroscopy, elemental analyses, thermogravimetric analysis and powder X-ray diffraction properties of 1 are also investigated.     

Folded Solitary Wave Excitations for （2＋1）-Dimensional Nizhnik-Novikov-Veselov System

With the help of an improved mapping approach and a linear-variable-separation approach, a new family of exact solutions with arbitrary functions of the （2＋1）-dimensional Nizhnik-Novikov-Veselov system （NNV） is derived. Based on the derived solutions and using some multi-valued functions, we find a few new folded solitary wave excitations for the （2＋1）-dimensional NNV system.     

Symmetry Groups and New Exact Solutions of （2＋1）-Dimensional Dispersive Long-Wave Equations

Using the modified CK＇s direct method, we derive a symmetry group theorem of （2＋1）-dimensional dispersive long-wave equations. Based upon the theorem, Lie point symmetry groups and new exact solutions of （2＋1）- dimensional dispersive long-wave equations are obtained.     

开展3＋1培养模式 科学地发展地实践信息与计算科学专业的建设

结合农垦院校办学特色和信息与计算科学专业的办学定位和办学指导思想,科学地发展地调整课程体系的设置,集思广益,认真制定、修订和运行教学计划;优化实践教学设置和深化实践教学内容,并积极建立长期的稳定的校外实习基地;与北京科瑞尔思研究院—大庆实训实习基地合作开展3＋1培养模式,收到良好效果.     

Demonstration of Inverse Scattering Transform in G-L-M Formalism for NLS Equation in Normal Dispersion with Non-vanishing Boundary

Using the integral representation of the Jost solution, we deduce some conditions as the kernel function N（x, y, t） if the Jost solution satisfies the two Lax equations. Then we verify the multi-soliton solution of NLS equation with non-vanishing boundary conditions if we prove that these conditions can be demonstrated by the GLM equation, which determines the kernel function N （x, y, t） in according to the inverse scattering method.     

Optimum fluorescence emission around 1.8 μm for LiYF4 single crystals of various Tm3＋-doping concentrations

In this paper, optical spectra of LiYF4 single crystals doped with Tm3＋ ions of various concentrations are reported. The emission intensity at 1.8 ktm first increases with increasing Tm3＋ concentration, and reaches a maximum value when the concentration of Tm3＋ is about 1.28 mol%, then it decreases rapidly as the concentration of Tm3＋ further increases to 3.49 mol%. The emission lifetime at 1.8 p.m also shows a similar tendency to the emission intensity. The maximum lifetime of 1.8 μm is measured to be 17.68 ms for the sample doped with Tm3＋ of 1.28 mol%. The emission cross section of 3F4 level is calculated. The maximum reaches 3.76 × 10 -21 cm2 at 1909 nm. The cross relaxation （3H6, 3H4 →3 F4, 3F4） between Tm3＋ ions and the concentration quenching effect are mainly attributed to the change of emission with Tm3＋ concentration. The largest quantum efficiency between Tm3＋ ions is estimated to be ,-147% from the measured lifetime and calculated radiative lifetime. All the results suggest that the Tm3＋/LiYF4 single crystal may have potential applications in 2 μm mid-infrared lasers.     

Physics program of open charm and heavy cc states at the BES-Ⅲ experiment

We present the physics program of the open charm and heavy cc states above the DD production energy threshold, which will be studied with the BES-Ⅲ detector at the BEPC- Ⅱ collider in the coming years. Based on some full Monte Carlo simulations with the BES-Ⅲ detector, we predict the accuracy levels on measuring some physical quantities related to D^0, D^＋ and Ds^＋ decays as well as some non-charmed decays of the heavy cc states.