ICP–AES法测定低合金钢中的微量硼

采用电感耦合等离子体发射光谱法(ICP–AES)测定低合金钢中硼元素的含量。采用密闭微波消解法对样品进行溶解,考察了铁基体元素和共存元素对硼元素测定的影响,确定了硼元素的分析线为208.959 nm,通过基体匹配消除基体的影响。硼的质量浓度在0~5.00μg/m L范围内与谱线强度呈良好的线性,相关系数r2=0.999 9,方法检出限为0.004μg/m L,加标回收率为96%~103%,测定结果的相对标准偏差为1.5%~2.9%(n=8)。该方法具有较高的灵敏度和准确度,满足低合金钢中硼元素的分析要求。     

积分型Cauchy中值定理的推广及逆问题

给出了一个积分型Cauchy中值定理的推广,并讨论了连续函数的积分型Cauchy中值定理的逆问题.     

混合价三核锰配合物Mn3O(O2CCCl3)6(py)2(H2O)的合成、晶体结构及磁性

A new mixed-valence trinuclear oxo-centered manganese complex Mn₃O(O₂CCCl₃)₆(py)₂(H₂O) was prepared by the reaction of NⁿBu₄MnO₄ with Mn(OAc)₂·4H₂O, trichloroacetic acid and pyridine in absolute EtOH. The crystal structure was determined. The complex crystallizes in monoclinic, space group P2₁/c, unit cell parame-ters, a=14.951(1), b=20.791(2), c=17.882(1)?,α=γ=90°, β=102.67(1)°. Variable temperature solid state magnetic susceptibility study shows that the complex has an antiferromagnetic exchange interaction. CCDC: 183369.     

基于分布式光纤传感阵列的管网泄漏监测系统研究

复杂液压管网的泄漏检测是液压系统面临的难点之一.采用LabVIEW与FoxPro数据库结合的方法,开发了阵列式光纤传感管网泄漏监测系统软件.该软件控制NI公司数据采集卡PXI-6133采集经调制后的光纤传感器干涉信号,再对获得的信号进行降噪处理,根据降噪后的波形是否出现零点频率判断管道是否泄漏并进行报警;该系统还可实时...     

痕量分析用储存容器的选择与清洗

对痕量分析用实验器皿的选择及清洗方法进行了研究,介绍了不同材料实验器皿对常见痕量杂质测量的干扰情况,同时提出了常用实验器皿的清洗程序以及高纯试剂的储存方法。     

Study on the Supramolecular Interaction of β-Cyclodextrin with Gemfibrozil by Spectrofluorimetry and Its Analytical Application

The supramolecular interaction of gemfibrozil with β-cyclodextrin （β-CD） was studied by spectrofluorimetry. The mechanism of the inclusion was discussed by spectrofluoremetry, infrared spectrum and ^1H NMR spectrum. The results showed that a 1 ： 1 （β-CD ： gemfibrozil） complex was formed with an apparent association constant of 3.844 × 10^3 L·mol^-1. Based on the enhancement of the fluorescent intensity of gemfibrozil, a spectrofluorimetric method for the determination of gemfibrozil in bulk aqueous solution in the presence of β-CD was developed. The linear range was 3.30 ng·mL^- 1 -6.00 ug·mL^-1 with the detection limit of 0.980 ng·mL^-1. There was no interference from the excipients normally used in tablet composition and the serum main compositions. The proposed method was then successfully applied to the determination of gemfibrozil in capsules and serum.     

三核锰配合物[Mn_3O(O_2CCH=CHCH_3)_6(py)_3]ClO_4·py的合成,晶体结构及磁性(英文)

0 Introduction Molecular-based magnetic materials have attractedmuch attention in designing and synthesizing a newclass of magnetic clusters with high spin ground stateand high critical temperature. The synthesis andmagnetic properties of oxo-centered trinuclear man-ganese complexes have been a focus of intense research     

过渡金属催化有机钛试剂的偶联反应研究进展

有机钛试剂廉价低毒,形态多样,具有优异的化学、区域和立体选择性.通过调整中心钛原子的配体可对有机钛试剂的反应活性进行调控.近年来,有机钛试剂参与的偶联反应引起了化学家们的广泛关注.从有机钛试剂类型出发,就过渡金属催化有机钛试剂的偶联反应进行了简要综述.     

电位滴定求导法测定硼化物中硼含量

建立电位滴定求导法测定硼化物中硼含量的新方法,解决滴定过程中指示剂显色不明显以及变色范围单一的缺点。利用样品前处理获得含硼组分溶液,以氢氧化钠标准溶液进行滴定,使用pH计记录pH值,绘制出滴定溶液体积对于溶液pH值的变化曲线,利用该曲线导数最大点求得硼含量。用该方法测定标准物质ERM–ED102、ERM–ED103,测定结果与标准值吻合,硼含量测定结果的相对标准偏差为0.2%~5.7%(n=7)。该方法快速、准确,灵敏度高,适用于硼化物中硼含量检测。