Studies on Fragrance Raw Materials of α-Terpineol Analogues

Thirty four α-substituted or α, α-disubstituted-( 1-methylcyclohexen-4-yl )methanols and α-substituted or α,α-disubstituted-(4-methylcyclohexyl) methanols weresynthesized. Thirty two of them are new compounds. 1H NMR and IR spectra of allthe compounds were determined, MS spectra of some of them were obtained as well.The characteristic odors were evaluated.Keywords Fragrance raw materials,α-Terpineol analogues, Synthesis, Structuredetermination     

高效液相色谱法测定盐酸羟甲唑啉滴鼻剂的稳定性

The stability of oxymetazoline hydrochloride nasal solution was determined by HPLC and the initialaverage rate method. The procedure was carripd out on a 250mm×4. 6mm column with 5μm ODS using wa-ter-methanol-sodium acetate solution(lmol/L)-glacil acetic acid-triethylamine as mobile phase,with UV de-tection at 280nm. The elution was performed at the flow rate of lmL/min. The results show that the expirydate of this preparation is about three years at room temperature.     

多孔硅表面Ag层对吸附其上的若丹明B染料分子表面增强Raman散射的影响

采用溶液电镀方法在多孔硅表面制备纳米尺寸的银颗粒,测量了不同镀银多孔硅表面吸附的ＲｈＢ染料分子以及固态的ＲｈＢ染料的Ｒａｍａｎ散射谱。在相同的激发强度下,固态ＲｈＢ染料的Ｒａｍａｎ散射最弱,而镀银的多孔硅表面具有明显的增强效果（～１０＾４）。     

火焰原子吸收光谱法间接测定青霉素V钾

基于青霉素V钾在酸性条件下的水解产物可与Pb2 + 形成沉淀 ,用火焰原子吸收光谱法测定沉淀中铅的含量 ,可间接测定药片中青霉素V钾的含量。在优化条件下 ,测定青霉素V钾的线性范围为 5 .15× 10 -5～ 4 .12× 10 -4mol/L ,线性回归方程为A =2 .4 2× 10 3 c - 0 .0 6 3 1,相关系数为 0 .999 1,检出限为 7.392× 10 -7mol/L ,测定结果的相对标准偏差为 0 .0 6 %～ 0 .6 9% ,回收率为 97.8%～ 10 2 .0 %。     

A study on free volume of acrylonitrile‐styrene copolymer and methyl methacrylate‐styrene copolymer by using positron annihilation

The o‐Ps lifetime τ₃ and the intensity I₃ of ST‐AN copolymers and ST‐MMA copolymers have been determined by using the positron annihilation technique. The average free volume hole radius R is estimated according to Tao's and Eldrup's model. The result shows that the average free volume hole size mainly attributes to lateral group volume and polarity of macromolecular chain as well as polymerizing temperature, and the o‐Ps intensity I₃ to the effect of the lateral group volume and the polarity. © 1999 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 37: 465–472, 1999     

Event-based state estimation for a class of complex networks with time-varying delays: A comparison principle approach

The paper is concerned with the state estimation problem for a class of time-delayed complex networks with event-triggering communication protocol. A novel event generator function, which is dependent not only on the measurement output but also on a predefined positive constant, is proposed with hope to reduce the communication burden. A new concept of exponentially ultimate boundedness is provided to quantify the estimation performance. By means of the comparison principle, some sufficient conditions are obtained to guarantee that the estimation error is exponentially ultimately bounded, and then the estimator gains are obtained in terms of the solution of certain matrix inequalities. Furthermore, a rigorous proof is proposed to show that the designed triggering condition is free of the Zeno behavior. Finally, a numerical example is given to illustrate the effectiveness of the proposed event-based estimator.     

Simultaneous determination of positional isomers of benzenediols by capillary zone electrophoresis with square wave amperometric detection

A capillary zone electrophoresis method coupling square wave amperometric detection (SWAD) for the simultaneous determination of positional isomers of benzendiols (i.e. o-, m-, p-benzenediols) has been developed. Effects of several factors, such as the composition of the running buffer, the pH value, separation voltage, injection time and the potential applied to the working electrode, were investigated to acquire the optimum conditions. The efficacy of the boric acid and ascorbic acid in the running buffer were discussed. o-, m-, p-Benzendiols can be well separated within 8 min in a 50 cm length of 50 microm diameter fused-silica capillary at a separation voltage of +15 kV. Operated in a wall-jet configuration, a 100 microm Pt-disk electrode used as the working electrode exhibits good response for the analytes. The relation between peak current and analyte concentration was linear over two orders of magnitude with detection limits (S/N = 3) ranging from 0.5 to 1.5 microM for all analytes. The proposed method has been successfully applied to monitor the o-, m-, p-benzendiols contents in the environmental wastewater samples with satisfactory assay results.     

Preparation and characterization of silicon monoxide/graphite/carbon nanotubes composite as anode for lithium-ion batteries

Silicon monoxide/graphite/multi-walled carbon nanotubes (SiO/G/CNTs) material was prepared by ball milling followed by chemical vapor deposition method and characterized by X-ray diffraction, scanning electron microscopy (SEM), galvanostatic charge–discharge, and AC impedance spectroscopy, respectively. The results revealed that SiO/G/CNTs exhibited an initial specific discharge capacity of 790 mAh g⁻¹ with a columbic efficiency of 65%. After 100 cycles, a high reversible capacity of 495 mAh g⁻¹ is still retained. The improved electrochemical properties were due to beneficial SEI by the SEM and EIS results.     

From synthetic to biogenic Mg-containing calcites: a comparative study using FTIR microspectroscopy

The formation mechanism of the thermodynamically unstable calcite phase, very high Mg calcite, in biological organisms such as sea urchin or corallina algae has been an enigma for a very long time. In contrast to conventional methods such as KBr pellet Fourier Transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD), FTIR microspectroscopy (FTIRM) provides additional information about a local disorder such as an amorphous phase or the occlusion of Mg ions in the calcite lattice. In this work, we characterise for the first time systematically synthetic and biogenic Mg-containing calcium carbonate samples (especially sea urchin teeth--SUT) in detail by using two FTIRM instruments and compare these samples with KBr pellet FTIR measurements. Furthermore, we present spectra from geogenic calcite and dolomite minerals, recorded with both FTIRM systems, as well as KBr pellet FTIR spectra as references. We analyse the spectra by applying multi-peak curve fitting on the in-plane-bending (ν(4)) and out-of-plane (ν(2)) bands. Based on the obtained results we attribute the two singlet bands at ～860-865 cm(-1) and ～695-704 cm(-1) observed in the SUT FTIRM spectra to the existence of amorphous calcium carbonate (ACC), and report for the first time the existence of ACC at the mature end of SUT. In the other three studied biominerals, however, we did not find any ACC. Also, based on the FTIRM results, we observe that not only ν(4), but also ν(2) shifts to higher wavenumbers if more calcium ions are replaced by magnesium ions in the calcite lattices.     

自适应模拟退火遗传算法在薄膜厚度及光学常数反演中的应用

准确的测量薄膜的厚度和光学常数,在薄膜的制备、研究和应用中都是十分重要的。借助Cauchy色散模型,通过薄膜透过率测量曲线,用改进的自适应模拟退火遗传算法对透过率曲线进行全光谱拟合,从而反演得到薄膜的厚度和光学常数。对由电子束蒸发制备的TiO2单层膜和SiO2/TiO2双层膜的厚度和光学常数进行了测量计算。实验结果表明,计算得到的光学参数与实测结果相一致,厚度误差小于2nm,在560nm波长处折射率误差小于0.03。