Laser action of C,N, O,F, Cl,and Br in hollow cathode discharges

C, N, O, F, Cl, and Br red and infrared laser emission was investigated using hollow cathode discharges in gas mixtures of helium and molecules containing the corresponding atoms. A total of 33 laser lines with wavelengths from 0.7 to 2.0m was observed. Three laser lines of atomic C, five laser lines of atomic N, two laser lines of atomic Cl and five laser lines of atomic Br were observed for the first time. Dissociation charge transfer and dissociative excitation transfer are suggested as being responsible for populating the upper laser levels.     

Characteristics of Polyaniline/Si Heterojunction Solar Cell By Electrochemical Dye Sensitization

Using the electrochemical polymerization dye sensitization （ECDS） method, polyaniline （PAn）, which is used as top region material in solar cells, is sensitized with direct blue dye（DS）, and sensitized Al grid/DS-PAn/n-Si/Al heterojunction solar cells is prepared by ECDS. Influences of the ECDS on the absorption spectrum and the junction characteristics of the solar cell were discussed, and the output characteristics were measured. The results show that the absorption spectrum of the sensitized PAn films is much wider and stronger in Vis-range; the diode quality factor is about 6.3 and the height of latent barrier potential of p-n junction is 0.89 eV; the short-circuit current and the conversion efficiency of sensitized DS- PAn/Si heterojunction solar cells are greatly improved, which the short-circuit current can increase 6 times, the fill factor is 57% and the efficiency can reach 1.42 % under the illumination of 37.2 W/m^2 , respectively.     

图模式挖掘中的子图同构算法

图模式挖掘问题在Web挖掘、生物信息学、社会关系等众多领域有广泛的应用,它涉及到子图的搜索以及子图的同构问题.这两个问题都具有相当高的计算复杂度,现有的子图同构问题大多采用最小编码算法,但对无标签图特别是对无标签无向图,该算法效率较底,从而子图的同构成为图模式挖掘问题的一个瓶颈.针对无标签图,以代数理论为基础,分别利用度序列和特征值构造了两种子图同构算法,用于对有向图和无向图的同构判别.最后对2个真实生物网络进行了仿真实验,结果表明,算法的效率优于现有算法.     

A hollow cathode bismuth ion laser

cw laser oscillations of Bi II at 680.9, 660.0, and 571.9 nm have been achieved for the first time by using a bismuth hollow cathode discharge. In addition, laser oscillations of Bi I at 1.1711 m in the afterglow were observed. The ionic laser lines are excited by Penning ionization. The atomic line is produced by recombination of the bismuth ions and lowenergy electrons in the afterglow.     

Analyses and Simulation of V-I Characteristics for Solar Cells Based on P-N Junction

Through theoretical analyses of the Shockley equation and the difference between a practical P-N junction and its ideal model, the mathematical models of P-N junction and solar cells had been obtained. With Matlab software, the V-I characteristics of diodes and solar cells were simulated, and a computer simulation model of the solar cells based on P-N junction was also established. Based on the simulation model, the influences of solar cell＇s internal resistances on open-circuit voltage and short-circuit current under certain illumination were numerically analyzed and solved. The simulation results showed that the equivalent series resistance and shunt resistance could strongly affect the V-I characteristics of solar cell, but their influence styles were different.     

一种基于代谢路径构建系统发生树的有效方法

构建系统发生树是研究物种起源和演化的重要手段.本文基于KEGG(Kyoto Encyclopedia of Genes and Genomes)代谢路径,引入图论的"核"概念,提出一种构建系统发生树的方法.首先解决在无数据丢失前提下,代谢路径数据的提取和表示问题,其次将不同代谢路径的相似度定义为图的核部分与非核部分各自匹配程度的加权之和,利用距离矩阵构建物种间的系统发生树.通过大量试验数据和NCBI(National Center for Biotechnology Information)分类法进行比较,验证了本文方法的有效性.     

Optical and Electrical Properties of Polyimide Thin Films Doped-Cu-phthalocyanine Polymerized by Vapor Phase Deposition

Using Cu-phthalocyanine(CuPc),4,4’-diaminodiphenyl ether and pyromellitic dianhydride as monomer materials, polyimide(PI) thin films doped-CuPc have been prepared onto glass substrate by vapor phase co-deposition polymerization under a vacuum of 2×10~(-3)Pa and thermal curing of polyamic acid film in at temperature of 150-200℃ for 60min. In this process, the polymerization can be carried out through controlling the stoichiometric ratio, heating time and deposition rates of the three monomers. IR spectrum identifies the designed chemical structure of the polymer. The absorption of polyimide doped-CuPc is very intense in vis-range and near-infrared by UV-Vis spectrum. And, the PI films doped-CuPc polymerized by vapor phase deposition have uniformity, fine thermal stability and good nonlinear optical properties, and the third-order optical nonlinear susceptibility χ~((3)) with degenerate four-wave mixing can be 1.984×10~(-9)ESU.     

Preparation and Characterization of Polyimide Attached with Azo——dye Chromophore Side Chain

In order to improve the nonlinear optical property and stability of azo--dye chromophore, the nonlinear optical polyimide (NLOPI) attached with azo chromophore side chain is synthesized by diazo coupling reaction of 4-nitrobenzenediazonium tetrafloroborate. The designed chemical structure of production can be proved in the infrared spectrum and ultraviolet-visible absorption spectrum. The NLOPI exhibited UV--Vis absorption of the azobenzene chromophore in the vicinity of the wavelengths of 330 and 490 nm. The broad amorphous peak proved that the NLOPI was amorphous with a little periodical structure along the side chain. According to transmission electron microscope, the NLOPI film was homogeneous. NLOPI only displayed a decrease in mass of about 5% at the temperature of 400℃ through thermogravimetric analysis.     

Investigation of hollow cathode Ge II and Te II lasers

Eighteen laser transitions were observed in Te and Ge hollow cathode discharges, four of which (6294, 5649, and 5488 Å of Te II and 5893 of Ge II) are reported for the first time. Charge exchange, Penning ionization, and radiative cascade processes are suggested as being responsible for the population of the upper laser levels.     

聚(2-甲氧基-5-辛氧基)对苯乙炔/单壁碳纳米管复合材料的光致发光特性

采用原位聚合法在无水四氢呋喃(THF)溶液中制备了聚(2-甲氧基-5-辛氧基)对苯乙炔(MOPPV)/单壁碳纳米管(SWNTs)复合材料。通过对该复合材料的红外光谱、X射线衍射、透射电镜、扫描电镜等的研究,证实SWNTs已聚合到MOPPV上且被MOPPV紧密有效地包覆,形成了纳米线网状结构。通过紫外-可见(UV-Vis)吸收光谱和光致发光(PL)谱发现:随着SWNTs掺杂量的增加,该复合材料的吸收强度逐渐增强且最大吸收峰出现红移,其发光强度呈现先升高后降低的趋势,发光峰蓝移。当SWNTs掺杂质量分数为3.85%时,复合材料的发光强度最大,此时最大发光峰位较纯MOPPV蓝移8 nm。研究结果表明:在MOPPV中掺入一定量的SWNTs,能有效地增强复合材料的光致发光强度。