Synthesis and photoluminescence of single crystals europium ion-doped BaF2 cubic nanorods

In this work, we used the hydrothermal method to synthesize Eu³⁺ ion-doped cubic BaF₂ nanorods, which is a luminescent material. The clubbed structures were well crystallized and exhibited face-centred cubic structures, as indicated by powder X-ray diffraction, scanning electron microscopy, electron diffraction, and transmission electron microscopy. The luminescent properties were studied, and local symmetry surrounding Eu³⁺ ions and electronic transition processes included. The results indicated that Eu³⁺ occupied only one C_4ν site in nanorods.     

Synthesis and Crystal Structure of Trigadolinium Bromoorthosilicate，Gd_3Br（SiO_4）_2

ＳｙｎｔｈｅｓｉｓａｎｄＣｒｙｓｔａｌＳｔｒｕｃｔｕｒｅｏｆＴｒｉｇａｄｏｌｉｎｉｕｍＢｒｏｍｏｏｒｔｈｏｓｉｌｉｃａｔｅ，Ｇｄ_３Ｂｒ（ＳｉＯ_４）_２ＭａｏＪｉａｎｇ－Ｇａｏ；ＺｈｕａｎｇＨｏｎｇ－Ｈｕｉ；ＨｕａｎｇＪｉｎ－Ｓｈｕｎ（ＳｔａｔｅＫｅ?..     

Some observations on the synergistic extraction of uranium(VI) with double chelating agent systems

A study on the synergistic extraction of uranium(VI) from nitric acid media with double-chelating agent systems 1-phenyl-3-methyl-4-benzoyl-pyrazolone-5 (PMBP) plus thenoyltrifluoroacetone (TTA), and 1-phenyl-3-methyl-4-benzoyl-pyrazolone-5 plus 1-phenyl-3-methyl-4-trifluoroacetyl-pyrazolone-5 (PMTFP) is described. Some synergistic effects have been observed. The experimental results suggest that the composition of synergistic complex species is UO₂PMBP·TTA and UO₂PMBP·PMTFP, respectively. The equilibrium constants for these synergistic extractions are calculated by three methods and the mechanism and the regularity of extraction are discussed as well.     

A Novel Dimeric Coumarin from Clausena lenis

A novel dimeric coumarin (1), a dimeric of seselin named diseselin A, was isolated from the aerial part of Clausena lenis. The structure was elucidated based on the MS, 1D and 2D NMR data.     

CO(υ)高振动激发态向C2H2的振动传能研究

用时间分辨富里叶红外发射谱研究了高振动激发态ＣＯ向Ｃ２Ｈ２的传能，得到了ＣＯ（ｖ＝１－３）各振动态布居及其随时间的变化。利用微分法解出弛豫微分方程组，获得ＣＯ（ｖ＝１－３）向Ｃ２Ｈ２的传能速率常数分别为：２．０±０．１，６．０±０．２和９．４±０．８（１０＾－１３ｃｍ＾３·ｍｏｌｅｃｕｌｅ＾－１·ｓ＾－１）。传能速率随着振动量子数的增加而迅速增加。ＣＯ的振动能应向Ｃ２Ｈ２的对称伸缩模ｖ２近共振Ｖ－     

聚丙烯与SBS嵌段共聚物共混时的结晶行为

用偏光显微镜,小角光散射,动态力学测量和DSC等方法研究了聚丙烯和SBS共混物的结晶行为。结果表明,SBS的混入可以降低聚丙烯的结晶程度和阻碍球晶的形成,因而有利于提高聚丙烯塑料的抗冲击性能。从DSC实验也看到共混物中的聚丙烯具有较高的结晶速率。     

Laser ablation in analytical chemistry-a review

Laser ablation is becoming a dominant technology for direct solid sampling in analytical chemistry. Laser ablation refers to the process in which an intense burst of energy delivered by a short laser pulse is used to sample (remove a portion of) a material. The advantages of laser ablation chemical analysis include direct characterization of solids, no chemical procedures for dissolution, reduced risk of contamination or sample loss, analysis of very small samples not separable for solution analysis, and determination of spatial distributions of elemental composition. This review describes recent research to understand and utilize laser ablation for direct solid sampling, with emphasis on sample introduction to an inductively coupled plasma (ICP). Current research related to contemporary experimental systems, calibration and optimization, and fractionation is discussed, with a summary of applications in several areas.     

Molecular films of water-miscible ionic liquids formed on glassy carbon electrodes: characterization and electrochemical applications

This letter describes the formation and possible electrochemical applications of molecular films of water-miscible imidazolium-based ionic liquids (ILs) on glassy carbon (GC) electrodes. X-ray photoelectron spectroscopy (XPS) and electrochemical results indicate that the water-miscible ILs used in this study can interact with the GC electrode and form molecular films on the electrode surface. The formed molecular films are found to possess striking electrochemical properties such as electrocatalysis toward ascorbic acid (AA) and the capability to facilitate direct electron transfer of horseradish peroxidase (HRP). This demonstration would pave the way for new electrochemical applications of water-miscible ILs and is envisaged to be useful for the investigation of the electrochemical properties of water-miscible ILs in aqueous media provided the same counteranion is used as the supporting electrolyte.     

SMAI法制备的Cu催化剂的CO加氢催化

用溶剂化金属原子浸渍（SMAI）法制备了SiO2、Cr2O3负载Cu催化剂.XPS测定表明三种载体上的Cu几乎全部以零价态存在．X射线增宽法测定表明随着Cu含量增加Cu颗粒增大．Cu催化剂在CO加氢中的催化活性与载体、Cu颗粒大小和Cu价态有关．Cr2O3对Cu催化活性有促进效应．Cr2O3负载Cu催化剂活性随Cu颗粒减小而增大，而SiO2作载体时，颗粒大小对活性无影响，零价Cu0为催化活性中心     

The effect of B2O3 addition on the crystallization of amorphous TiO2-ZrO2 mixed oxide

The effect of B₂O₃ addition on the crystallization of amorphous TiO₂-ZrO₂ mixed oxide was investigated by X-ray diffraction (XRD), thermogravimetric and differential thermal analysis (TG/DTA). TiO₂-ZrO₂ mixed oxide was prepared by co-precipitation method with aqueous ammonia as the precipitation reagent. Boric acid was used as a source of boria, and boria contents varied from 2 to 20 wt%. The results indicate that the addition of small amount of boria (<8 wt%) hinders the crystallization of amorphous TiO₂-ZrO₂ into a crystalline ZrTiO₄ compound, while a larger amount of boria (?8 wt%) promotes the crystallization process. FT-IR spectroscopy and ¹¹B MAS NMR results show that tetrahedral borate species predominate at low boria loading, and trigonal borate species increase with increasing boria loading. Thus it is concluded that highly dispersed tetrahedral BO₄ units delay, while a build-up of trigonal BO₃ promote, the crystallization of amorphous TiO₂-ZrO₂ to form ZrTiO₄ crystals.