ICP—AES法测定硼酸铝钇钕（NYAB）激光晶体中的Nd

应用ICP-AES法分析自倍频激光晶体(NYAB)样品中的Nd,在石墨坩埚中于500℃用NaOH熔融分解样品,方法的回收率为96%～105%,测定的相对标准偏差为1.42%,方法简便,可给出满意的分析结果。     

Immobilization of Glucose Oxidase on Cellulose／Cellulose Acetate Membrane and its Detection by Scanning Electrochemical Microscope （SECM）

Cellulose/cellulose acetate membranes were prepared and functionalized by introducingamino group on it, and then immobilized the glucose oxidase (Gox) on the functionalizd membrane.SECM was applied for the detection of enzyme activity immobilized on the membrane.Immobilized biomolecules on such membranes was combined with analysis apparatus and can beused in bioassays.     

First Synthesis of 2a-Thiol Ether Analog of Docetaxel

The chemistry of anticancer drug paclitaxel (=Taxol, 1a) has been extensively explored in recent years. A variety of its analogs with modified taxane frame work or substitutions to its core structure, as well as C-13 substituted isoserine side chains have been synthesized and biologically evaluated1. The marketing of docetaxel (=Taxotere, 1b) is one of the fruitful results from these research efforts. The beginning of clinical trial for analog 2 developed by Indena is the new example. Ba…     

A High Sensitivity Detection Method of Singlet Oxygen and Superoxide Anion

This paper, for the first time, reports a method that can be used as a highly sensitive probe for singlet oxygen (^1O2) and superoxide anion (O2^-) in vitro or in vivo. FCLA(3,7-dihydro-6-{4-[2-(N‘-(5-fluoresceinyl)thioureido)ethoxy]phenyl}-2-methylimidazo{1,2-a}pyrazin-3-one sodium salt), a chemiluminescence (CL) analysis reagent, has been reported to sensitively react with ^1O2 and O2^- to emit photons with a spectral peak of 525nm. In this work,when human serum albumin (HSA) was added into FCLA solution to enhance the CL intensity,approximately 20 times, compared to that without HSA. The enhanced CL had the same 525 nm spectral peak, identical to that without HSA. By gradually reducing the molecular oxygen content in the solution, we find that the auto-oxidation of oxygen molecules dissolved in the solution plays an important role in the CL process. Based on these experimental evidences, we propose a novel and highly sensitive detection method of ^1O2 and O2^- which may have a great potential in chemical and medical applications.     

The rotation and the phase transition in solid C60

The interaction between C60's in solid C60 has been calculated by (exp-6-1) potential, and the cause and the controlled factor of the high rapid rotations of C60 's were discussed. In order to describe the disordered degree of C60 rotation, an equivalent M is introduced. The phase transitions at the ~260 K and at the ~90 K are studied from the viewpoint of C60 rotation. The potential barriers of the ordered rotation below the ~260 K and the disordered rotation above the ~260 K have been given, and the effect of the external pressure on the temperature of phase transition has also been given.     

有机磷化合物的质谱研究(Ⅶ)——二氮二磷杂环戊烷衍生物的化学电离质谱

本文报道了七种4.5-二氧代-2-硫代-1,3,2,4-二氮二磷杂环戊烷衍生物的化学电离质谱(CIMS,甲烷为反应气),结果表明:CIMS中准分子离子MH~+为基峰离子;MH~+离子易发生失去H_2S,CO,C_3H_6等小分子的裂解,(M+C_2H_5)~+离子存在再断裂。     

Density of supercritical CO_2-tetrahydrofuran binary mixture and the partial molar volume of the cosolvent

The densities of supercritical CO2-tetrahydrofuran (cosolvent) binary mixture weremeasured at temperatures in range of 308.15 to 323.15 K and at pressure up to 16.5 MPa.The concentrations of tetrahydrofuran were from 0 to 0.57 mol/L.The partial molar volume of tetrahydrofuran was calculated based on the relationship between the density of the mixture and the concentration of the cosolvent.It is observed that the partial molar volume of the cosolvent is negative and the absolute value decreases with increasing pressure and the concentration of the cosolvent.     

A New Triterpenoid Saponin and a New Glycoside from Epigynum aurilum

A new triterpenoid saponin with novel sugar moiety (1), a new trisaccharide derivative (2), as well as a known monosaccharide derivative (3), were isolated from the dried stem of Epigyhum aurilum. The structures of compounds 1 and 2 were determined by MS and NMR spectram analyses.     

Synthesis and Ionic Conductivity of Network Polymer Electrolytes with Internal Plasticizers

Network polymer electrolytes with free oligo(oxyethylene) chains as internal plasticizers were prepared by cross-linking poly(ethylene glycol) acrylates. The effects of salt concentration and properties of internal plasticizers on ionic conductivity were studied.     

Adsorption Behavior of a Water-soluble Porphyrin at the Glass-water Interface as Studied by Synchronous Total Internal Reflection Fluorescence Spectroscopy

Total imernal reflection fluorescence spectroscopy (TIRF) and synchronous scanning technique were combined to study the adsorption behavior of the meso-tetrakis (4-sulfonatophenyl)porphyrin (TPPS) at the glass-water interface without any surfactant. The pH dependence of synchronous fluorescence signal at the interface was analyzed. Both unprotonated (TPPS^4-) and diprotonated (H2TPPS^2-) forms of TPPS were observed at the interface. But the interface favored the adsorption of. The apparent estimated pKa2 value shifted from 5.00 in the bulk solution to 2.7 at the interface. STIRF provides a good technique to study multi-component systems at the interface.