掺铒氟（卤）磷碲酸盐玻璃的上转换发光性能研究

研究了掺铒氟（卤）磷碲酸盐玻璃的吸收光谱和上转换荧光光谱，探讨了Er^2＋在氟（卤）磷碲酸盐玻璃中的上转换发光机理．在975nm激光二极管抽运下产生强烈的上转换红光及绿光。且红光的发光强度要远远大于绿光．以PbCl2取代PbF2后，红光的发光强度下降，而绿光却没有明显变化；以ZnCl2取代ZnF2达5mol％时，红光和绿光的发光强度均明显增大．

TeO2-ZnCl2-BaO-NaF玻璃系统的结构及中红外透过特性的研究

制备了一种新型的氧卤碲酸盐玻璃：（80-x）TeO2—15ZnCl2-xBaO-5NaF（x=30、20、10、0mol％），对玻璃的机械强度、热稳定性、拉曼光谱、紫外吸收光谱、红外透过光谱等特性进行了研究．通过拉曼光谱分析研究了玻璃组分含量的变化对玻璃结构和红外透过性能的影响．结果表明，随着BaO含量的增加，玻璃在红外波段透过率显著增加，并且红外透过截止波长向长波方向移动，本文对这一实验结果进行了机理性的研究探讨．同时，通过在熔制过程中通入高纯O2，以及引入适量的卤化物有效地除去玻璃中的[OH]基团，使

Upconversion luminescence of Tm3+/Yb3+-codoped oxyhalide tellurite glasses

Thermal stability, Raman spectra and blue upconversion luminescence properties of Tm-3divided by /Yb-3divided by -codoped halide modified tellurite glasses have been Studied. The results showed that the mixed halide modified tellurite glass (TFCB) has the best thermal stability, the lowest phonon energies and the strongest upconversion emissions. The effect of halide on upconversion intensity is observed and discussed and possible upconversion mechanisms are evaluated. The intense blue upconversion luminescence of Tin (3+) in TFCB Glass may be a potentially useful material for developing upconversion optical devices.. (C) 2004 Elsevier Ltd. All rights reserved.

近红外超快强激光在LiF晶体内空间选择性诱导产生色心

通过显微镜聚焦近红外超快强激光作用在垂直于激光束移动的LiF晶体样品上，在LiF晶体中连续地诱导产生色心。以一定的间隔．反复移动该激光束的焦斑可在LiF晶体内空间选择性地诱导产生稳定的色心区。测定了不同条件下形成的色心区的吸收光谱，结果表明用近红外超快强激光可在LiF晶体中诱导产生具有激光效应的色心。

Chemical nano-gardens: growth of salt nanowires from supramolecular self-assembly gels.

In this article, we examine the phenomenon of single-crystal halide salt wire growth at the surface of porous materials. We report the use of a single-step casting technique with a supramolecular self-assembly gel matrix that upon drying leads to the growth of single-crystal halide (e.g., NaCl, KCl, and KI) nanowires with diameters ~130-200 nm. We demonstrate their formation using electron microscopy and electron-dispersive X-ray spectroscopy, showing that the supramolecular gel stabilizes the growth of these wires by facilitating a diffusion-driven base growth mechanism. Critically, we show that standard non-supramolecular gels are unable to facilitate nanowire growth. We further show that these nanowires can be grown by seeding, forming nanocrystal gardens. This study helps understand the possible prefunctionalization of membranes to stimulate ion-specific filters or salt efflorescence suppressors, while also providing a novel route to nanomaterial growth.

In situ intercalation dynamics in inorganic-organic layered perovskite thin films.

The properties of layered inorganic semiconductors can be manipulated by the insertion of foreign molecular species via a process known as intercalation. In the present study, we investigate the phenomenon of organic moiety (R-NH3I) intercalation in layered metal-halide (PbI2)-based inorganic semiconductors, leading to the formation of inorganic-organic (IO) perovskites [(R-NH3)2PbI4]. During this intercalation strong resonant exciton optical transitions are created, enabling study of the dynamics of this process. Simultaneous in situ photoluminescence (PL) and transmission measurements are used to track the structural and exciton evolution. On the basis of the experimental observations, a model is proposed which explains the process of IO perovskite formation during intercalation of the organic moiety through the inorganic semiconductor layers. The interplay between precursor film thickness and organic solution concentration/solvent highlights the role of van der Waals interactions between the layers, as well as the need for maintaining stoichiometry during intercalation. Nucleation and growth occurring during intercalation matches a Johnson-Mehl-Avrami-Kolmogorov model, with results fitting both ideal and nonideal cases.

Fixation of carbon dioxide into aliphatic polycarbonate, cobalt porphyrin catalyzed regio-specific poly(propylene carbonate) with high molecular weight

Cobalt porphyrin complex ((TPPCoX)-X-III) (TPP = 5, 10, 15, 20-Tetraphenylporphyrin; X = halide) in combination with ionic organic ammonium salt was used for the regio-specific copolymerization of propylene oxide and carbon dioxide. A turnover frequency of 188 h(-1) was achieved after 5 h, and the byproduct propylene carbonate was successfully controlled to below 1%, where the obtained poly(propylene carbonate) (PPC) showed number average molecular weight (M-n) of 48 kg/mol, head-to-tail content of 93%, and carbonate linkage of over 99%.

Promoting carbonization of polypropylene during combustion through synergistic catalysis of a trace of halogenated compounds and Ni2O3 for improving flame retardancy

The effect of combination between a trace of halogenated compounds (such as ferric chloride and ammonium bromide) and Ni2O3 particles on the carbonization of polypropylene (PP) was investigated during combustion. The results showed a synergistic catalysis of combined halogenated compounds with Ni2O3 in promoting the formation of the residual char during combustion. The investigation on the promotion mechanism showed that halide radical releasing from halogen-containing additives worked as a catalyst to accelerate dehydrogenation-aromatization of degradation products of PR which promote the degradation products to form the residual char catalyzed by nickel catalyst.

An Engineering-Purpose Preparation Strategy for Ammonium-Type Ionic Liquid with High Purity

A new strategy for preparing ammonium-type ionic liquid (IL) by acid/base neutralization reaction was proposed. The method contributed to preparing hydroxide-based ammonium IL and resulting task specific ionic liquid (TSIL) with high purity using a low-costly and environment-friendly synthetic. route. Halide contamination in the prepared ILs could be markedly decreased than those prepared by well-established anion metathesis method. Moreover, some novel TSILs composed of cations and anions with big steric hindrances could be prepared by this method. Physicochemical properties of the bifunctional TSILs, i.e., density, water content, decomposition temperature, and munal solubility, were also studied in this article.

Electrochemical catalysis and thermal stability characterization of laccase-carbon nanotubes-ionic liquid nanocomposite modified graphite electrode

The hydrophobic carbon nanotubes-ionic liquid (CNTs-IL) get forms a stable modified film on hydrophobic graphite electrode surface. Laccase immobilized on the CNTs-IL gel film modified electrode shows good thermal stability and enhanced electrochemical catalytic ability. The optimal bioactivity occurs with increasing temperature and this optimum is 20 degrees C higher in comparison to free laccase. The improvement of laccase thermal stability may be due to the microenvironment of hydrophobic CNTs-IL gel on graphite electrode surface. On the other hand, the sensitive detection of oxygen has been achieved due to the feasibility of oxygen reduction by both of laccase and nanocomposite of CNTs-IL gel. Furthermore, the laccase hybrid nanocomposite also shows the fast electrochemical response and high sensitivity to the inhibitors of halide ions with the approximate IC50 of 0.01, 4.2 and 87.5 mM for the fluoride, chloride and bromide ions, respectively. It implies the feasibility of laccase modified electrode as an inhibition biosensor to detect the modulators of laccase.

Atom transfer radical polymerization of butadiene using MoO2Cl2/PPh3 as the catalyst

Atom transfer radical polymerization has been used to successfully synthesize polybutadiene. This was achieved by using MoO2Cl2/triphenyl phosphine as the catalyst and the various organic halide compounds such as methyl-2-chloropropionate, CCl4, 1,4-dichloromethyl benzene, I-phenylethyl chloride, and benzyl chloride as initiators. The monomer conversion increased up to 50% with polymerization time. The polydispersity indices of the polymers were as high as above 1.5. However, the polymerizations were controlled and the polydispersity indices of the polymers were less than 1.5 throughout the polymerization in reverse atom transfer radical polymerization. The chemical structure of the polymer obtained was characterized by (HNMR)-H-1 and FTIR. The valency states of molybdenum in this reactive system were detected by UV-vis spectra.

Polymeric pH indicators immobilized PVA membranes for optical sensors of high basicity based on a kinetic process

Two kinds of polymeric pH indicators PPF (phenolphthalein-formaldehyde product) and CPF (o-cresolphthalein-formaldehyde product) immobilized cross-linked poly(vinyl alcohol) membranes (PPF-PVA and CPF-PVA) for optical intermittent determination of high basicity ([OH-] = 1-8 M) based on a kinetic process were developed. In our previous work, we had demonstrated that PPF-PVA and CPF-PVA could perform the determination of high pH values from pH 10.0 to 14.0. Here the discoloring kinetic behaviors of PPF-PVA and CPF-PVA were compared with those of free phenolphthalein, o-cresolphthalein and thymolphthalein. Experimental results and theoretical analysis indicated that the response behaviors of the optodes' membranes in concentrated NaOH solutions were diffusion-independent and still complied with the pseudo-first-order kinetics. In addition, two data analysis methods for determination were presented. One was directly based on the reduced absorbance: the other was based on the discoloring kinetic constant. It was found that the latter could perform a rapid (60 s) and reliable (relative standard deviation: 2.6%) determination for high basicity.

Synthesis, crystal structure, and photoluminescent property of a novel heterobimetallic Zn(II)-Ag(I) cyano-bridged coordination polymer incorporating,a pentameric unit [Ag(CN)(2-)](5) assembled by argentophilic interaction

A new photoluminescent heterobimetallic Zn(II)-Ag(I) cyano-bridged coordination polymer, [Ag5Zn2(tren)(2)(CN)(9)] (tren = tris(2-aminoethyl)amine) (1), has been synthesized and structurally characterized. It features rare linear pentameric unit of dicyanoargentate(I) ions assembled by d(10)-d(10) interaction as building blocks. Solid state emission spectrum of I shows strong ultraviolet luminescence with emission peak in the range of 376 nm.

Hydrothermal synthesis, structure, and characterization of two one-dimensional chainlike hybrid complexes [(CuX)(2)(o-phen)](infinity) (X = Br, Cl; o-phen = o-phenanthroline)

Two novel organic-inorganic hybrid complexes [(CuX)(2)(o-phen)](infinity) (X = Br (1), Cl (2); o-phen = o-phenanthroline) have been synthesized hydrothermally and characterized structurally by elemental analyses, IR, ESR, XPS spectrum, TG analyses and single-crystal X-ray diffraction. Both title compounds exhibit novel one-dimensional chainlike copper halide scaffolding constructed by the unusual [Cu3X3] hexagon motifs by sharing opposite edges, where a single Cu site of each [Cu3X3] hexagon is chelated with N donors of o-phen group. To our knowledge, such basic o-phen-copper halide skeleton has not been reported hitherto. Moreover, TG analyses indicate that both title compounds possess high thermal stability.

ELECTROCATALYTIC OXIDATION AND ION-CHROMATOGRAPHIC DETECTION OF BR-, I-, SO32-, S2O32- AND SCN- AT A PLATINUM PARTICLE-BASED GLASSY-CARBON MODIFIED ELECTRODE

A modified method for dispersing platinum particles on a glassy carbon (GC) electrode was investigated. The ultramicro Pt particle-modified electrode obtained exhibited high catalytic stability and activity towards the oxidation of some halide ions (Br-, I-) and inorganic sulfur species (S2O32-, SO32- and SCN-). These anions were separated and detected by using ion chromatography and electrochemical detection via this novel dispersed Pt particles-GC working electrode. The detection limits were 20 ng/ml for Br-, 1.0 ng/ml for I-, 10 ng/ml for SO32- and 4.0 ng/ml for SCN-. This method was employed for the analysis of industrial and environmental waste waters.