Microencapsulation of phosphor particles with the drying‐in‐liquid method in parallel with the suspension polymerization method and effect on afterglow luminance property

Strontium aluminate particles as phosphor particles were microencapsulated with the drying‐in‐liquid method in parallel with the suspension polymerization method in order to increase the waterproof and to improve afterglow luminance property. In this study, ethylene glycol was used as the continuous phase instead of water to prevent phosphor particles from deteriorating at the microencapsulation process, and polystyrene was used as the more hydrophobic microcapsule shell. Styrene monomer was used as the solvent of polystyrene at the drying‐in‐liquid method and as the polymerizable monomer at the suspension polymerization method at the same time. The content and the waterproof could be considerably increased with the drying‐in‐liquid method in parallel with the suspension polymerization method as compared with only the drying‐in‐liquid method, because the denser microcapsule shell without any tiny holes and cracks could be formed. The decrease due to water in brightness of afterglow luminance of phosphor particles could be prevented by microencapsulating with the drying‐in‐liquid method in parallel with suspension polymerization method. Copyright © 2017 John Wiley & Sons, Ltd.     

纳米氧化铁溶胶中铁含量测定方法的研究

在测定纳米氧化铁溶胶中铁含量时，EDTA滴定法和光度法的可靠性和重现性均可与原子吸收光谱法相比拟，所测得数据为优化合成纳米氧化铁溶胶条件提供了可靠简便的方法。     

气相氟化合成氢氟烯烃催化剂的研究进展

氢氟烯烃(HFOs)是重要的精细化工中间体, 气相氟化合成HFOs具有可连续生产、 避免对反应釜的严重腐蚀等优点, 简化生产工艺已成为国内外生产氟化工产物的重要方法. 本文简要介绍了合成HFOs的常见催化反应类型以及反应机制, 并按照主催化剂成分分类概述气相氟化合成所用的催化剂, 介绍了各类催化剂的传统制备方法(如沉淀法等)和新的制备方法(如自组装法、 溶液燃烧合成法、 硬模板法、 静电纺丝法等), 以及催化性能, 提出了该催化剂的未来发展方向.     

Evaluation of a dry, rehydratable film method for rapid enumeration of Staphylococcus aureus

Results with the new 3M Petrifilm Rapid S. aureus Count (RSA) Plate method were compared with those of the classical Baird-Parker agar (BPA) method for detection and enumeration of Staphylococcus aureus. Studies on 219 bacterial strains demonstrated that the Petrifilm RSA plate is more sensitive than and as specific as the classical BPA method for confirmed identification of S. aureus. Counts of colonies from 71 pure cultures, 61 naturally contaminated food samples, and more than 750 artificially inoculated food samples showed that the Petrifilm RSA method was as effective as the classical BPA method for identification and enumeration of S. aureus. The Petrifilm RSA method gave results in one-third the time required for the classical method.     

μ-氧代四苯基双核金属卟啉仿生催化剂的研究进展

综述了国内外及本课题组有关μ-氧代四苯基双核金属卟啉仿生催化剂合成及应用的最新研究进展和成果. 重点介绍了μ-氧代四苯基双核金属卟啉的合成方法, 即两步合成法、柱色谱分离法、一步合成法、自氧化法以及本课题组最新开发的一锅法. 其中一步合成法和自氧化法由于具有适用范围广、收率高等优点, 将成为μ-氧代四苯基双核金属卟啉的主要合成方法. 而一锅法尽管目前收率尚较低, 但由于其完全去掉了中间反应产物的分离和提纯以及原料和溶剂的损失, 而使工艺流程得到大大简化、能耗显著降低, 将成为一种极有发展潜力的合成方法. 系统地阐述了μ-氧代四苯基双核金属卟啉在仿生催化领域中的应用. 尤其是以μ-氧代四苯基双核金属卟啉为催化剂、O2或空气为氧化剂的催化氧化反应, 具有催化剂用量少、氧化剂清洁且廉价易得、无需助催化剂和共还原剂、反应条件温和等优点, 将成为未来仿生催化氧化领域研究的前沿和热点.     

Development of a new QuEChERS method based on dry ice for the determination of 168 pesticides in paprika using tandem mass spectrometry

This study describes a new QuEChERS method referred to as the dry ice-partitioning QuEChERS method. This current method can be differentiated from the other QuEChERS methods in the sense that it uses dry ice rather than salts or buffers to extract and partition pesticides in the first extraction step. The dry ice-partitioning QuEChERS method consists of extraction method A (for detection of the acetonitrile layer) and extraction method B (for detection of both acetonitrile and aqueous layers). The extraction efficiency was then compared with the citrate-buffering QuEChERS method by means of recovery. Recovery values of the tested 168 pesticides were above 76%, with relative standard deviations of less than 20%. Certain problematic pesticides, including benfuracarb, carbosulfan, dichlofluanid, probenazole, pymetrozine, tolylfluanid, TFNA, and TFNG evidenced acceptable recoveries via the dry ice-partitioning QuEChERS method compared to the less than 70% recoveries of the citrate-buffering QuEChERS method examined herein. The matrix effect of paprika on the method developed herein was not significant, and matrix-matched calibration was performed well, with an r(2)≥0.99. The dry ice-partitioning QuEChERS method is capable of detecting the aqueous layer as well as the acetonitrile layer; this interesting feature makes it worth in application as an alternative QuEChERS method for the multiresidue analysis of pesticides within a broad polarity range in various matrices.     

Development of effective Stokesian dynamics method for ferromagnetic colloidal dispersions (cluster-based Stokesian dynamics method)

We have developed a new Stokesian dynamics (SD) method for nondilute colloidal dispersions, which enables us to reduce drastically the computation time. To verify the validity of the present method, which is called the "cluster-based SD method," three-dimensional simulations of a ferromagnetic colloidal dispersion have been carried out for a simple shear flow. The correlation function and viscosity have been evaluated to compare the results obtained by the present method with those obtained by the ordinary SD method and by the method of ignoring hydrodynamic interactions between particles. The results obtained here are summarized as follows. The transient properties from an initial state obtained by the present method agree well with those obtained by the ordinary method, even if a radius r(clstr), which defines the cluster formation, is taken as a small value such as r(clstr)=1.2d (d is the particle diameter). Also, the equilibrium properties such as the pair correlation function and viscosity obtained by the present cluster-based method are in satisfactory agreement with those obtained by the ordinary SD method. Furthermore, the cluster-based method drastically reduces the computation time to about one-fourteenth to one-seventieth that of the ordinary method. It is clear from these results that the cluster-based SD method is significantly superior to the ordinary SD method for ferromagnetic colloidal dispersions for which a large model system such as N=1000 or 10,000 is indispensable in simulations.     

GPC-多检测联用技术测定聚己内酯分子量及其分布

介绍一种用于生物可降解高分子材料聚已内酯(PCL)及其改性高分子的分子量和分子量分布测定的GPC-示差折光(RI)-示差黏度(DV)-直角光散射(RALLS)多检测联用技术.叙述了该方法的实验原理,并对测试过程中的有关技术及实验结果进行了讨论.该方法可准确测定聚己内酯(PCL)及其改性高分子的分子量及其分布、特性黏度分布、Mark-Houwink方程系数以及高分子尺寸等重要参数.通过对窄分布PS标样验证,分子量测定结果的相对误差在1%之内.     

两种采样方法检测空气中偏二甲肼含量的精密度检验

以自制的偏二甲肼动态配气系统配制已知浓度空气样品为测试环境,采用溶液吸收法采样并简化了G JB2373-1995的分析步骤,使用改进方法与标准方法分别进行实验。用F检验法比较两种方法所对应的两组检测数据,结果表明,两种方法的精密度相当,而溶液吸收法省时、省力。     

On the extended method of calculation of atomic structures

The extended method of calculation of atomic structures is characterized. This method is understood as the use of as many radial orbitals as there are electrons in the atom under consideration. The process of passing from the ordinary method of calculation to the extended one is described. In the method proposed the additional complications appear within the confines of dealing with radial variables only. The general rules for carrying out the calculations, in applying the extended method, are formulated.     

痕量钒的分析进展

综述近年来测定痕量钒的主要方法,包括光度法如常规光度法、流动注射光度法、催化动力学光度法、萃取光度法、导数光度法以及原子吸收法、荧光法、交流示波极谱法、催化动力学离子选择电极法和流动注射化学发光法等。     

Biodegradabilities of some chain oils in groundwater as determined by the respirometric BOD OxiTop method

The respirometric BOD OxiTop method was used to monitor the biodegradation of different chain oils (mineral, rapeseed and tall oils) over 28 days in groundwater, as well as in standard conditions described by OECD 301 F. The aim of the study was to gather more information about the biodegradability of forestry oils in groundwater, as well as about the suitability of the automatic OxiTop method for biodegradation measurements. The BOD OxiTop method proved to be a precise and reliable technique for determining the biodegradations of different oils. Some comparative studies were also made using a traditional IR method in order to clarify the total oil concentrations. The results show that if biodegradation only is to be monitored, the OxiTop method is preferable. This is due to the influence of other reactions aside from biodegradation on total hydrocarbon concentrations when using the IR method.     

混合溶剂火焰原子吸收法直接测定原油中的镍

混合溶剂火焰原子吸收法直接测定原油中的镍刘广东袁存光张丙华刘文钦（石油大学（华东），山东东营２５７０６２）彭力（中国石油天然气总公司环保处，北京１００７２４）关键词原油，混合溶剂，无机盐标准，原子吸收法，镍测定原油中，微量元素镍、钒、铁、铜的存在对...     

双电解池正反馈示波计时电位法研究

双电解池正反馈示波计时电位法研究郑建斌，高鸿，朱俊杰，胡娟（西北大学电分析化学研究所，西安，７１００６９）（南京大学化学系）关键词正反馈示波计时电位法，双电解池，切口由于在经典示波计时电位法中所施加的交流极化电流的频率很高，充电电流就构成了影响去极剂...     

Dilution method in x-ray fluorescence spectrometry

The Lachance-Traill method was modified to a dilution method that retains all the advantages of the original method plus it enables the determination of as many elements as one pleases and is far simpler mathematically. The method had been tested with determination of copper, molybdenum, zinc, and arsenic in copper intermediates.     

纳米四氧化三铁(Fe3O4)的制备和形貌

纳米Fe₃O₄因其特殊的理化性质和在生物医学领域潜在的应用价值而得到广泛研究。本文综述了纳米Fe3O4的制备方法，包括直流电弧等离子体法、热分解方法、沉淀法、水热法、电化学法、微乳液法、溶胶-凝胶法、有机物模板法、回流法等，结合作者在Fe3O4纳米粒子制备方面的最新工作，介绍了Fe3O4纳米粒子的新颖形貌。对纳米级Fe3O4制备研究的发展趋势进行了展望。     

Near-infrared spectrophotometric determination of compositions of fullerene samples

A novel method has been developed for the sensitive and accurate determination of compositions of fullerene samples. The method is based on the synergistic use of spectrophotometric measurements and partial least square method. The method is not only simple, inexpensive and fast but also is non-destructive. Compositions of various fullerene samples including fullerite which is the precursor to C(60) and C(70), can be directly and non-destructively determined by this method without any time-consuming separation step as in the HPLC method or destruction as in the MS method.     

The gravimetric determination of thallium(i) as thallium(i) tetraphenylboron

A gravimetric method for the determination of thallium(I) as thallium(I) tetraphenylboron has been developed. The method compares favorably with the classical chromate method. The effect of acid concentration and interference by other metal ions was studied as well as the thermal stability of the precipitate.     

维生素E母核合成研究进展

综述了2,3,5-三甲基氢醌的合成工艺进展,主要包括2,3,6-三甲基苯酚(TMP)氧化还原法、TMP羟基化法与异佛尔酮法,详细阐述了其中关键反应步骤的机理,并指出新型催化剂的开发与应用将是此领域的重点研究方向。     

Classification and Prediction of Geological Samples by Principal Component Analysis

The principal component analysis is an ancient multivariate statistical method[1]. It is extensively used in spectrometry with the popularization of computer and development of the method of chemometrics. It is regarded as an effective method of multivariate statistical analysis. The principal component analysis is universally included in common program package of multivariate statistical analysis. The method, as well as other multivariate calibration methods, combined with artificial neural networks forms the foundation of the chemometrics.