Polymer bound glutamic acid salicylaldehyde Schiff‐base complex ­catalyst for oxidation of olefins with ­dioxygen

The polymer bound Schiff‐base ligand (PS‐SalGlu) has been prepared from polystyrene bound salicylaldehyde and glutamic acid, and its complex (PS‐SalGlu‐Co) has also been synthesized. The polymer ligand and its complex were characterized by infrared spectroscopy, small area X‐ray photoelectron spectroscopy, and inductively coupled plasma‐atomic emission spectro (ICP‐AFS). In the presence of the complex, cyclohexene can be effectively oxidized by molecular oxygen without reductant. The long‐chain linear aliphatic olefins, such as 1‐octene, 1‐decene, 1‐dodecene and 1‐tetradecene, can be directly oxidized by molecular oxygen catalyzed by PS‐SalGlu‐Co, which affords the 1,2‐epoxy alkane. Copyright © 2001 John Wiley & Sons, Ltd.     

铋(Ⅲ)-8-羟基喹哪啶体系极谱行为——表面活性剂增敏机理和分析应用——Ⅱ.铋(Ⅲ)-8-羟基喹哪啶络合物电极反应和十二烷基苯磺酸钠增敏机理

试验表明,铋(Ⅲ)-8-羟基喹哪啶(8-OXQ)络合物(pHll,-0.60V)的峰电流(p)具吸附特性,为准可逆电极反应过程,其电子转移数(n),传递系数(α)及饱和吸附量(Γ_ο)分别为3,0.45,6.5×10~(-12) mol/cm~2。加入十二烷基苯磺酸钠(SDBS)未形成三元络合物,因SDBS的超载强烈吸附,引起诱导吸附,电双层结构激烈变化,而使电流峰形巨变,电流峰高(i_p)增大10余倍。讨论并指出SDBS对Bi(Ⅲ)与8-羟基喹啉(8-OX)及衍生物络合吸附电流增敏或抑制,与试剂组分、结构、解离态及络合物存在状态、电荷数、符号有关。     

四(2─咪唑基)卟啉在水溶液中的性质及其在乙酸中与Co(Ⅱ)(OAc)2的反应动力学研究

合成了水溶性四（２－咪唑基）卟啉，研究了它在水溶液中的聚合性质。实验发现Ｈ２ＴＩｍＰ水溶液在ＰＨ＝０，６时遵守Ｂｅｅｒ定律，并呈单体形式存在。用光谱滴定法测定了Ｈ２ＴＩｍＰ加质子的平衡常数。用紫外可见分光光度计研究了在乙酸溶剂中Ｈ２ＴＩｍＰ与Ｃｏ（Ⅱ）（ＯＡｃ）２反应的动力淡。     

气相色谱质谱法快速测定人血浆中克仑特罗

血浆样品经0.01mol·L-1盐酸和无水乙醇浸取,在碱性条件下用氯仿萃取,GG-MS-选择离子测量法测定,外标法定量。在选定的色谱条件下,盐酸克仑特罗的检出限为0.05ng,线性范围为0.1-100ng,方法的平均回收率为95.6％,RSD小于6.82％(n=6)。该法毋需衍生化,基质无干扰,简便可靠,适用于生物材料中克仑特罗的快速分析。     

Ionic limiting molar conductivity calculation of Li-ion battery electrolyte based on mode coupling theory

A method is proposed based on mode coupling theory in which the ion transference number is introduced into the theory. The ionic limiting molar conductivities of LiPF6, LiClO4, LiBF4, LiCF3SO3, Li(CF3SO3)2N, LiC4F9SO3, and LiAsF6 in PC(propylene carbonate), GBL(gamma-butyrolactone), PC(propylene carbonate)/EMC(ethylmethyl carbonate), and PC(propylene carbonate)/DME(dimethoxyethane) are calculated based on this method, which does not involve any adjustable parameter. The results fit well to the literature data which are calculated by an empirically adjusted formula. This presents a potential way to calculate the conductivities of Li-ion battery electrolytes.     

Self-assembly of gold nanoparticles on fullerene nanospheres

A C60-pyrrolidine derivative with a hydrophobic-hydrophilic-hydrophobic structure (2-{3,4-di{2-[2-(2-decyloxyethoxy)ethoxy]ethoxy}}phenyl-3,4-fulleropyrrolidine, DTPF) has been synthesized and well-characterized. This compound could form stable nanospheres by simply injectingits tetrahydrofuran (THF) solution into water and then removing THF by purging gaseous nitrogen in sequence. Novel nanoassemblies of DTPF nanospheres and gold nanoparticles were obtained through in situ photoreduction of aqueous HAuCl4 in the presence of DTPF nanospheres, which were confirmed by UV-visible, transmission electron microscopy, X-ray powder diffraction, and X-ray photoelectron spectroscopy methods. It is proposed that the interaction between the positively charged nitrogen atom and the gold nanoparticles is the main driving force for the formation of the nanoassemblies.     

Nanometer-sized zirconium dioxide microcolumn separation/preconcentration of trace metals and their determination by ICP-OES in environmental and biological samples

A new method is proposed using a microcolumn (20 mm × 2.0 mm) packed with nanometer-sized zirconia as solid-phase extractor for the separation/preconcentration of Mn, Cu, Cr, Zn, Ni and Co prior to their determination by inductively coupled plasma optical emission spectrometer (ICP-OES) in environmental samples. The factors affecting the separation and preconcentration of analytes such as pH, sample flow rate and volume, eluent concentration and volume were determined, interfering ions were studied, and the optimal experimental conditions were established. The adsorption capacity of nanometer-sized ZrO₂ for Mn, Cu, Cr, Zn, Ni and Co was found to be 1.3, 1.3, 1.7, 2.0, 3.9 and 1.5 mg g⁻¹, respectively. The detection limits of the method were 12, 58, 24, 2, 7 and 36 ng L⁻¹, respectively, with a preconcentration factor of 25. The precision of this method was 1.7% (Mn), 2.9% (Cu), 5.9% (Mn), 3.8% (Mn), 6.2% (Mn) and 4.3% (Mn) with 9 determinations of 10 ng mL⁻¹ of target analytes, respectively. The method was successfully applied to the determination of trace metals in lake water, dried fish samples, certified reference materials of human hair and milk, and provided satisfactory results.     

2，4，6-三硝基间苯二酚钡一水化合物的热分解动力学(英)

0IntroductionBarium2,4,6鄄trinitroresorecinatemonohydrate,Ba(TNR)·H2O,hasgooddetonatingpropertiesandissensitivetoflame.Itcanbeusedasinitiatingagent,igniterpowderordelaypowder.Itspreparation[1],pro鄄perties[1],crystalstructure[1]andthermalbehavior[2]haveb…     

Effects of Calcination Temperature on the Acidity and Catalytic Performances of HZSM-5 Zeolite Catalysts for the Catalytic Cracking of n-Butane

The acidic modulations of a series of HZSM-5 catalysts were successfully made by calcination at different treatment temperatures, i.e. 500, 600, 650, 700 and 800 ℃, respectively. The results indicated that the total acid amounts, their density and the amount of B-type acid of HZSM-5 catalysts rapidly decreased, while the amounts of L-type acid had almost no change and thus the ratio of L/B was obviously enhanced with the increase of calcination temperature (excluding 800 ℃). The catalytic performances of modified HZSM-5 catalysts for the cracking of n-butane were also investigated. The main properties of these catalysts were characterized by means of XRD, N2 adsorption at low temperature, NH3-TPD, FTIR of pyridine adsorption and BET surface area measurements. The results showed that HZSM-5 zeolite pretreated at 800 ℃ had very low catalytic activity for n-butane cracking. In the calcination temperature range of 500-700 ℃, the total selectivity to olefins, propylene and butene were increased with the increase of calcination temperature, while, the selectivity for arene decreased with the calcination temperature.The HZSM-5 zeolite calcined at 700 ℃ produced light olefins with high yield, at the reaction temperature of 650 ℃ the yields of total olefins and ethylene were 52.8% and 29.4%, respectively. Besides, the more important role is that high calcination temperature treatment improved the duration stability of HZSM-5zeolites. The effect of calcination temperature on the physico-chemical properties and catalytic performance of HZSM-5 for cracking of n-butane was explored. It was found that the calcination temperature had large effects on the surface area, crystallinity and acid properties of HZSM-5 catalyst, which further affected the catalytic performance for n-butane cracking.     

Surface phase behavior and microstructure of lipid/PEG-emulsifier monolayer-coated microbubbles

Langmuir trough methods and fluorescence microscopy were combined to investigate the phase behavior and microstructure of monolayer shells coating micron-scale bubbles (microbubbles) typically used in biomedical applications. The monolayer shell consisted of a homologous series of saturated acyl chain phospholipids and an emulsifier containing a single hydrophobic stearate chain and polyethylene glycol (PEG) head group. PEG-emulsifier was fully miscible with expanded phase lipids and phase separated from condensed phase lipids. Phase coexistence was observed in the form of dark condensed phase lipid domains surrounded by a sea of bright, emulsifier-rich expanded phase. A rich assortment of condensed phase area fractions and domain morphologies, including networks and other novel structures, were observed in each batch of microbubbles. Network domains were reproduced in Langmuir monolayers under conditions of heating–cooling followed by compression–expansion, as well as in microbubble shells that underwent surface flow with slight compression. Domain size decreased with increased cooling rate through the phase transition temperature, and domain branching increased with lipid acyl chain length at high cooling rates. Squeeze-out of the emulsifier at a surface pressure near 35 mN/m was indicated by a plateau in Langmuir isotherms and directly visualized with fluorescence microscopy, although collapse of the solid lipid domains occurred at much higher surface pressures. Compression of the monolayer past the PEG-emulsifier squeeze-out surface pressure resulted in a dark shell composed entirely of lipid. Under certain conditions, the PEG-emulsifier was reincorporated upon subsequent expansion. Factors that affect shell formation and evolution, as well as implications for the rational design of microbubbles in medical applications, are discussed.