全内反射型大模式面积光子晶体光纤设计

利用平面波展开法对全内反射型光子晶体光纤的模场分布进行了理论分析和数值模拟,发现通过改变光纤包层结构能够改变模场分布和色散特性,并且利用其特有的"无截止单模"特性,设计了大模式面积光子晶体光纤     

掺杂铽的对甲基苯甲酸锌发光材料的合成与荧光性能研究

采用流变相法合成了掺杂三价铽离子的对甲基苯甲酸锌发光材料。在紫外灯的照射下,观察比较了对甲基苯甲酸、对甲基苯甲酸锌以及掺杂Tb（Ⅲ）的对甲基苯甲酸锌盐的荧光现象,利用荧光分光光度计测定了三者的激发光谱和发射光谱,并讨论三者的发光特性和机理。结果表明：对甲基苯甲酸作为有机配体可以改善Tb^3＋离子的发光性能。     

多分叉和铁填充碳纳米管的合成与表征

以二环戊二烯和二茂铁为前驱体,通过化学气相沉积法可控地制备了多分叉的碳纳米管,在其分叉处观察到铁填充物。通过调变前驱物的比例、生长温度等条件能够有效地调变填充物Fe的含量。结果表明,前驱体中二茂铁的相对含量越高,分叉和填充现象越明显,说明铁物种在分叉形成中起重要作用。随着分叉次数的增加,支管的直径显著减小。     

Engineering of electronic and optical properties of ZnO thin films via Cu doping

ZnO thin films doped with different Cu concentrations are fabricated by reactive magnetron sputtering technique. XRD analysis indicates that the crystal quality of the ZnO:Cu film can be enhanced by a moderate level of Cu-doping in the sputtering process. The results of XPS spectra of zinc, oxygen, and copper elements show that Cu-doping has an evident and complicated effect on the chemical state of oxygen, but little effect on those of zinc and copper. Interestingly, further investigation of the optical properties of ZnO:Cu samples shows that the transmittance spectra exhibit both red shift and blue shift with the increase of Cu doping, in contrast to the simple monotonic behavior of the Burstein–Moss effect. Analysis reveals that this is due to the competition between oxygen vacancies and intrinsic and surface states of oxygen in the sample. Our result may suggest an effective way of tuning the bandgap of ZnO samples.     

Crystal Structure and Sensitive Response toward Al~(3+) of the Furaldehyde Schiff Base

A furaldehyde Schiff base, 4-[(2-furanylmethylene)amino]phenol(FMAP), was synthesized and fully characterized by elemental analysis, ~1 H-NMR, IR, MS, UV-Vis, fluorescence and single-crystal X-ray diffraction. It crystallizes in the monoclinic system, space group P2_1/n with a = 6.2566(6), b = 13.2273(11), c = 11.3056(9) ?, β = 93.1800(10)o, V = 934.19(14) ?~3, Z = 4, M_r = 187.19, D_c = 1.331 g/cm~3, λ = 0.71073 ?, F(000) = 392, GOOF = 1.022, R = 0.0396 and wR = 0.0992 for 4569 observed reflections with I 2σ(I). Fluorescent spectroscopic investigation revealed that the Schiff base exhibited a high selectivity and sensitivity toward Al~(3+) over other common metal ions in ethanol solution, and the detection limit of Al~(3+) is up to 1.2 × 10~(-7) M. The mass spectra and Job's plot analysis confirm the 1:1 stoichiometry between FMAP and Al~(3+).     

钨锌杂多酸盐催化合成庚酸乙酯

合成了K8[FeZnW11O39(H2O)]、K8[NiZnW11O39(H2O)]和K8[CoZnW11O39(H2O)]3种具有Keggin结构的钨锌混配型杂多酸盐催化剂,以无水乙醇和庚酸为原料,催化合成庚酸乙酯。结果表明最佳反应条件为:催化剂用量为原料质量的1%,催化剂在连续使用6次情况下活性无明显下降,3种催化剂中K8[NiZnW11O39(H2O)]的催化活性最好。     

H4SiW12O40/SiO2催化合成庚酸乙酯

以H4SiW12O40/SiO2为催化剂,庚酸和无水乙醇为原料,合成酒用香料庚酸乙酯。结果表明,复合硅钨杂多酸是合成庚酸乙酯的良好催化剂,适宜的工艺条件为：酸醇物质的量比为1∶2,催化剂用量3%,甲苯做带水剂8mL,反应时间2.5h,在此条件下产率可达49.5%。     

埋入SiO_2薄膜中纳米Ge的光学、电学性质和室温可见光致发光

用射频共溅射技术和真空退火方法，制备出埋入ＳｉＯ２基质中纳米Ｇｅ的复合膜（ｎｃＧｅ／ＳｉＯ２），通过喇曼散射、Ｘ射线衍射、室温光致发光（ＰＬ）、紫外可见光近红外吸收及电导温度关系等测量手段，较系统地研究了该复合膜的光学、电学、薄膜结构和光致发光性质，在室温情况下得到了有多个弱峰的、不对称的宽带ＰＬ谱，主峰能量约为２０５ｅＶ，这一结果同量子限制效应符合     

小分子荧光探针的光谱

运用紫外-可见光谱、荧光光谱法研究了以二烯酮为荧光团的1,5-双(4-羟基)-1,4-戊二烯-3-酮探针的光学性质.一系列pH滴定实验表明探针的紫外吸收和荧光光谱随溶液的pH值的改变而变化.同时,探针紫外吸收光谱发生明显的红移,荧光光谱强度也随之变化,在碱性条件下,相对荧光强度浮动较大.解离常数pK<,α>为9.25,...     

基于六元环生长机理高产制备碳纳米管

基于六元环生长机理,以苯为前驱物高产率地制备了多壁碳纳米管。通过调变及优化催化剂的组成和用量、苯通量、生长温度等参量,碳纳米管的最高产率可达859wt%。高分辨透射电子显微镜、扫描电子显微镜、热重-差热分析仪、X射线衍射等分析结果表明,本方法制得的碳纳米管产物的直径约20 nm,纯度高,具有良好的石墨化程度。