Hydrothermal Synthesis, Crystal Structure and Photoluminescent Property of a Novel Complex [Zn（OHCT）（1,2-BDC）]_n

A novel ligand 11-oxa-4,5,9,10,12,13-hexaaza-cyclopenta [b] triphenylene (OHCT) and its coordination polymer [Zn(OHCT)(1,2-BDC)]n 1 (1,2-BDC = 1,2-benzenedicarboxylate) were synthesized and characterized. Crystallographic data for OHCT: C14H6N6O5, Mr = 274.25, monoclinic, space group P21/c, a = 10.755(3), b = 11.710(4), c = 9.516(3) , β = 108.457(4)o, V = 1136.9(6) 3, Dc = 1.602 g/cm3, μ(MoKα) = 0.111 mm-1, F(000) = 560, Z = 4, the final R = 0.1534 and wR = 0.39709. Crystallographic data for 1: C22H10ZnN6O5, Mr = 503.73, triclinic, space group P , a = 6.1411(5), b = 10.9111(9), c = 14.1925(1) , α = 89.1830(1), β = 79.3030(1), γ = 84.6350(1)o, V = 930.36(1) 3, Dc = 1.798 g/cm3, μ(MoKα) = 1.376 mm-1, F(000) = 508, Z = 2, the final R = 0.0323 and wR = 0.0789. 1 has been obtained by using hydrothermal synthesis and characterized by elemental analysis, IR spectrum, thermal analysis, fluorescence spectrum and single-crystal X-ray diffraction. In complex 1, the zinc atom is five-coordinated with three carboxylate oxygen atoms from three different 1,2-BDC ligands and two nitrogen atoms from one OHCT ligand, showing a distorted trigonal bipyramidal configuration.     

硅锗量子阱发光器件的探索

介绍了提高硅发光效率的一些途径，关阐述硅锗合金的发光的基础上，分析了硅锗量子阱的光致发光机理及特性，并介绍了硅锗量子阱电致发光研究的进展。     

Si_(1-x)Ce_x/Si量子阱发光材料制备及特性研究

在si(100)衬底上用分子束外延成功生长了Si_(1-x)Ge_x/si量子阱发光材料,发现在生长过程中背景杂质含量直接影响材料的发光特性,用光致发光(PL)和卢瑟福背散射(RBS)对样品质量进行标定。在PL测量中观察到合金量子阱带边激子分辨峰,并对发光峰能和峰宽作了讨论。     

Rotation of hydrogen molecules during the dissociative adsorption on the Mg(0001) surface: a first-principles study

Using first-principles calculations,we systematically study the potential energy surfaces and dissociation processes of the hydrogen molecule on the Mg(0001) surface.It is found that during the dissociative adsorption process with the minimum energy barrier,the hydrogen molecule first orients perpendicularly,and then rotates tobecome parallel to the surface.It is also found that the orientation of the hydrogen molecule in the transition state is neither perpendicular nor parallel to the surface.Most importantly,we find that the rotation causes a reduction of the calculated dissociation energy barrier for the hydrogen molecule.The underlying electronic mechanism for the rotation of the hydrogen molecule is also discussed in the paper.     

重复频率低阻抗紧凑Marx脉冲功率源

为了实现重频脉冲功率源小型化,研制了基于快Marx发生器的紧凑型重频低阻抗脉冲功率源。采用大功率重频高压电源对Marx发生器充电,通过对充电电源和脉冲触发源的同步控制,实现对Marx发生器重频充电;Marx发生器中采用薄膜脉冲电容器、小型化气体开关、电感隔离以及SF₆气体绝缘等设计,以8级紧凑Marx发生器进行验证性研究,在16 Ω阻抗负载上实现了重复频率10 Hz、脉宽150 ns、峰值电压大于400 kV连续多脉冲输出;在此基础上,设计了18级紧凑型Marx发生器,在约18 Ω阻抗负载上输出功率达到33 GW,峰值功率密度大于150 GW/m³,实现重复频率5 Hz、脉宽约160 ns、峰值电压大于600 kV的连续多脉冲输出。为了降低Marx发生器的输出阻抗,采用4台电容器并联作为Marx发生器的一级储能模块,研制了同轴紧凑Marx脉冲功率源,有效减小放电回路电感,实现12 Ω低阻抗负载近似匹配输出,前沿减小至50 ns以下,脉宽约130 ns。     

一种基于电爆炸丝断路开关的多脉冲产生技术

 介绍了一种基于电感储能和电爆炸丝断路开关的多脉冲发生器。该发生器是由作为初级能源的脉冲电容器组、储能电感和多级串联的不同长度、不同截面积的电爆炸丝断路开关组成。实验中在约10 W电阻负载上获得了2个大于250 kV和3个大于200 kV的脉冲输出。脉冲数由串联丝阵级数决定,脉冲幅度和脉冲间隔可通过爆炸丝参数、电容器充电电压调节。     

聚对苯二甲酸乙二醇酯/聚乙二醇醚插层嵌段共聚物的结晶性能

合成了不同用量、不同分子量的聚乙二醇醚(PEG)或聚丁二醇醚(PTMC)与聚对苯二甲酸乙二醇酯(PET)/蒙脱土(MMT)的嵌段共聚物。研究了MMT在共聚物中的分散状态及PEG或PTMG对PET/MMT插层聚合物结晶性能的影响。结果表明,MMT在共聚物中以纳米尺寸分散;加入PEG或PTMG增强了聚酯链段的柔顺性,使共聚物熔体降温过程的结晶温度提高,冷结晶温度降低,即插层嵌段共聚物的结晶速率提高;在合成的共聚物中,分子量为2000,用量为DMT的6%的PEG对插层共聚物结晶速率的促进作用最大     

苯酚过氧化氢羟化过程中Dawson结构钼钒磷杂多化合物的ESR谱研究

研究了苯酚过氧化氢羟化过程中Dawson结构杂多化合物的ESR谱，通过对比不同反应时间后催化剂的波谱参数，分析了反应过程中V4+→V5+的变化情况．研究结果表明，在反应初期，催化剂仅存在少量V4+，在反应时间达到2h时V4+的含量迅速增多，并出现了V（Ⅰ）及V（Ⅱ）两种波谱参数相异的四价钒，其中V(Ⅰ)对应着V＝O键上的V4+，而V（Ⅱ）则对应着加氧中间物种，反应过程中V(Ⅱ)的含量迅速增多．两种钒均为羟化反应的活性中心     

Digital holography experiment of 3D detection of underwater bubble fields

Detection of underwater bubbles is one of the key issues of the research of ocean-atmosphere flux exchange. Digital holographic experiment is carried out based on Maeh-Zehnder digital holographic system, to detect the distribution of bubbles. Holographic images of the dynamical bubble fields are recorded by the chargecoupled device （CCD） video system and the tomographie images at different depth are reproduced. The distribution of sizes and densities of the bubbles is obtained through following steps as denoising, edgedetection, and bubble-recognition using Hough transform. Through the experiments, the efficiency and applicability of the digital holographic detection of underwater bubble fields are tested and verified.     

纳米Ge薄膜的制备及光致发光特性研究

采用直流磁控溅射技术在不同生长温度制备了一系列的Ge薄膜.应用拉曼散射、X射线衍射、光致发光等技术表征薄膜的结构.结果表明:Ge薄膜的结晶温度约为380℃,并且随着生长温度的升高,Ge的结晶性变好,晶粒长大;对不同尺寸Ge薄膜的光致发光研究表明:随着纳米Ge晶粒尺寸的减小,光致发光峰的相对强度逐渐增强,且发光峰位发生蓝移.用有效质量近似模型讨论了量子尺寸效应和介电限域效应对纳米Ge颗粒发光特性的影响.