Synthesis and Two-photon Absorption Properties of s-Triazine Derivatives

Two new s-triazine derivatives, which belong to linear dipolar type and triangle octupolar type respectively, have been synthesized. The structure of the dipolar compound has been determined by X-ray diffraction. The two-photon absorption cross-section σ, and the two-photon excited fluorescence (TPEF) intensities are increased significantly from dipolar compound to octupolar compound.     

ATOM TRANSFER RADICAL POLYMERIZATION OF 2,5-BIS[（4-HEXYLOXYPHENYL）OXYCARBONYL]STYRENE

A side-on liquid crystalline monomer, 2,5-bis[(4-hexyloxyphenyl)oxycarbonyl]styrene) (HPCS), was successfully polymerized via atom transfer radical polymerization (ATRP). The polymerization was catalyzed by CuBr/PMDETA in chlorobenzene at 90℃ with (1-bromoethyl)benzene as the initiator. The polymers have narrow MWD. It is the second example of mesogen-jacketed liquid crystalline polymer (MJLCP) prepared by ATRP.     

可移动激光质谱仪的研制与应用

激光质谱法是一种新的环境测污方法,具有高灵敏度、高选择性、多组分同时测量和快速实时的特点。本研究介绍了新近研制的可移动激光质谱仪的系统结构、各部分功能、原理以及主要技术指标。该仪器能在大气压下采样,并在设计过程中解决了记忆效应,使用输出波长248nm的KrF准分子激光器,可以对芳香烃进行多组分同时检测。该仪器对机动车尾气中苯系物含量的实时在线测量结果表明,尾气中含有苯、甲苯、二甲苯、三甲苯、萘、甲基萘等多种芳香烃污染物,检测的灵敏度达0．1mg／m^3,时间响应可达0．1s。     

SrB4O7:Pr^3+中Pr^3+的发光性质

本研究报道Pr^3+在SrB4O7中的发光性质,在SrB4O7中Pr^3+离子的4f5d能态高于1^S0能级,因此,在207nmUV光激发下,Pr^3+能够把所吸收的一个高能量的UV光子转换为两个可见光子的发射(光子倍增);在此氧化物基质中的光子倍增主要是由于阳离子处于弱的晶体场格位之中;由于与稀土离子弱联结相关的声子振动频率低(hωmax～1200cm^-1),因此还能观察到从3^P0能级向低能级的跃迁。第一个光子的发射由1^S0→1^G4(313nm),1^S0→1^D2(338nm)和1^S0→1^I6(405nm)的辐射跃迁组成;第二个光子的发射由3^P0和1^D2能级向低能级的辐射跃迁组成[3^P0→(3^HJ,3^FJ)和1^D2→(3^H4,3^H5)]。     

复合物邻二甲苯…NH3(ND3)分子间的振动

Resonant two photon ionization spectra of S1←S0 transition in complex o xylene…NH3(ND3) in supersonic molecular beam are observed using resonant two photon ionization,together with time of flight mass spectrometry. The spectra exhibit rich information on the complex intermolecular vdW vibrational modes.We have tentatively assigned all the observed spectral features.By analyzing the spectra,the stretching vibrational frequencies and two bending vibrational frequencies of the the complex are obtained.The structure of the complex has been obtained by ab initio computation method.     

卤化氢共振增强多光子电离光谱

测定了卤化氢(HCl, HBr 和HI) (2+1)共振增强多光子电离(REMPI)光谱, 采用模拟计算法分析推导出转动常数、谱带源以及Ω态振动谱带的同位素位移值. 得到的HCl数据同Green等人用常规分析法所推导的结果极为吻合. 得出8条振动谱带,其中包括V(¹∑⁺)态, E(¹∑⁺)的v'=4态以及HBr的5个新谱带, 此外还推导出HI的E态v'=1的4个振动谱带光谱参数. 观测了V和E态之间因同类相互作用而产生的不规则能级间距、转动参数和同位素位移. 讨论了HCl和HBr的E态和V态振动谱带中的转动谱线序列O和S对Q的强度比变化,提出了双光子激发机理.     

Clustering properties of partly charged superfine particles in a light medium

This paper investigated average cluster sizes （ACS） and cluster size distributions （CSD） at different shear rates by Brownian dynamics in non-, bi-, and uni-polar systems with partly charged superfine particles, The investigation indicates that clusters in non- polar systems are the weakest and easiest to be damaged by increasing shear stresses; charged particles play important and different roles： in bi-polar system, it intends to strengthen clusters to some extent provided that the sign-like ions homogeneously arranged; in uni-polar system charged particles cracked the clusters into smaller ones, but the small clusters are strong to stand with larger shear stress. The relationship between ACS and shear rates follows power law with exponents in a range 0.18-0.28, these values are in a good agreement with experiment range but at the lower limit compared with other systems of non-metallic cluster particles.     

镉离子响应性凝胶光子晶体传感膜的构建

将光子晶体与响应性水凝胶结合,采用“三明治”填充方法,以聚苯乙烯（PS）胶体晶体为模板,丙烯酰胺和烯丙基硫脲为单体制备得到一种对镉离子具有特异响应性的凝胶光子晶体传感膜,并对其进行了形貌表征和响应性研究。结果表明,该传感膜具有排列整齐的反蛋白石结构,可对不同浓度的Cd²⁺输出不同的光学信号。随着Cd²⁺浓度的增大,传感膜的Bragg衍射峰发生蓝移,并伴随有显著的颜色变化。在最优配比,适宜pH和离子强度条件下,衍射峰的最大位移值可达51.1 nm。在研究过程中发现其他干扰金属离子的存在不会影响传感膜对Cd²⁺的特异性响应,并且表现出了较快的响应速度。在多次循环实验中传感膜由于具备高度交联结构而表现出了良好的机械性和化学稳定性。该传感膜的构建为Cd²⁺的快速高效及裸眼可视检测提供了可能性。     

HCl/NH_3敏感的卟啉-二氧化硅反蛋白石光子晶体荧光传感器

将反蛋白石结构的光子晶体引入到腐蚀性气体检测体系,制备得到卟啉-二氧化硅反蛋白石光子晶体(TPP-SiO_2IOPCs)荧光传感器。相对于空白样,TPP-SiO_2IOPCs传感器实现了氯化氢(HCl)气体检测信号200倍的增强,这主要归因于反蛋白石型光子晶体的大孔结构和慢光子效应。同时,TPP-SiO_2IOPCs传感器对于HCl气体的猝灭效率可达75%,比空白样的提高了25%,而且经HCl气体处理后的传感器通入氨气(NH_3)后,初始的荧光强度几乎完全恢复。在HCl和NH_3条件下进行5个循环后,TPP-SiO_2IOPCs传感器表现出良好的可重复使用性。该研究对于发展高效的荧光传感器提供了新的思路。     

单光子LIF方法研究亚硝基苯266 nm光解动力学

用266 nm激光解离亚硝基苯（C6H5NO) 产生光解碎片NO,并利用单光子激光诱导荧光(LIF)技术（X2Πν″=0→A2Σ+ν′=0）测得初生态光解产物NO的振转光谱。根据计算所得的模拟光谱对光解碎片NO（X,ν″＝0)的转动量子数J″进行了归属,得到量子数最大到J″＝50.5的各转动能级的相对布居,这表明光解碎片NO具有较高的转动激发。提出了C6H5NO在266 nm下可能的光解机理。