电感耦合等离子体质谱法测定水产品中铬、铜、锌、砷、镉、铅的含量

取水产品样品0.500 0 g,加入硝酸5 mL、水2 mL、30%(质量分数)过氧化氢溶液1 mL,按微波消解程序进行消解,将消解液于100℃蒸发至1~2 mL,用水定容至25 mL。采用电感耦合等离子体质谱法测定上述溶液中铬、铜、锌、砷、镉、铅的含量。各元素测定值的相对标准偏差(n=6)在1.2%~5.9%之间,回收率在96.6%~102%之间。按上述方法分析标准物质GBW 10023、GBW 10024、GBW 10050,FAPAS质控基准物质TET012RM以及质控样品T07225QC,各元素测定值与认定值一致。     

Pr3＋掺杂的LaF3纳米微晶/氟氧化物玻璃陶瓷的VUV光谱

The vacuum ultraviolet (VUV) spectroscopic properties of praseodymium (Pr^3＋, 1at%) doped LaF₃ nanocrystals/glass at room temperature and 20 K are reported. Two types of Pr^3＋ ions, those in LaF₃ nanocrystals and those in the glass host, were excited to 4f 5d band by VUV using synchrotron radiation as an excitation source, and emissions of ¹S₀ → ¹D₂ (336 nm), ¹S₀ → ¹I₆ (397 nm ) of Pr^3＋ in the nanocrystals and emissions of 4f 5d → ³H_J, ³F_J of Pr^3＋ in the glass appeared at the same time. But unlike in the bulk sample crystals, emission of ³P₀ → ³H_J, ³F_J as the second step of the quantum splitting (QS) of Pr^3＋ in the LaF₃ nanocrystals was not observed at room temperature, which could be explained that Pr^3＋ ions in the glass absorbed the energy of ³P₀→ ³H₄ of Pr^3＋ in the nanocrystals. Two types of excitation spectra monitoring different emissions were also measured, so it could be observed that the lowest energy of 4f 5d band of Pr^3＋ in the nanocrystals was about 53 500 cm^-1 (186 nm) and in the glass about 33 800 cm^-1(295 nm), respectively. These emission and excitation spectra were contrasted to those of bulk sample crystals LaF₃∶Pr^3＋.     

流动体系高性能电流检测器的改进

采用在工作电极（ＷＥ）及辅助电极（ＣＥ）室衬垫尼龙网布的方法改进了本教研室提 出的 ＷＥ与ＣＥ正对面放置型的电流检测［１］。在进样 １００ μＬ样品（Ｂｒ－），流速２ ｍＬ／ｍｉｎ，检 测器电解效率达１８．９％，浓度电流线性范围为１０－２～１０－８ｍｏｌ／Ｌ，重复进样相对标准偏差小 于１％。     

金属-血清蛋白的结构研究Ⅲ.Ni2+离子诱导的HSA和BSA的缓慢构象变化

用紫外光谱观察到Ni2+离子与人或牛血清白蛋白相互作用有显著的滞后效应,表明Ni2+离子的结合可以诱导人或牛血清白蛋白发生从对Ni2+离子有较弱亲和力至较强亲和力构象态的缓慢变化(T-R转化);这一构象变化为试样的旋光能力随时间变化进一步证实;测得并讨论了这一构象变化的速度常数和活化参数;推测这一构象变化可能主要发生在蛋白质的IA亚区,并且很可能是一种促使IA亚区变得更加开放的"绞链式运动".     

稀土元素与3,4-二羟基苯甲醛缩邻氨基苯甲酸配合物的合成和表征

本文在三乙胺存在下合成了3,4-二羟基苯甲醛缩邻氨基苯甲酸(H_3L)与稀土元素的配合物。元素分析和摩尔电导值等确定其组成为[REL·nH_2O],(RE=La、Pr、Nd、Sm,n=3;RE=Gd、Dy、Ho、Yb、Y,n=4)。钆和钇配合物皆属重稀土组。磁化率、TG-DTA、IR和NMR等结果表明,配合物中不含硝酸根离子,负三价的配体离子以一种“扭曲”的形式与稀土离子配位。     

双轴拉伸PET薄膜成膜过程非晶区分子取向的WAXS研究

本文将常应用于小的角度范围(29_(CuK_α)<50°)的结晶峰和非晶峰的计算机分峰法,推广到PET薄膜的广角度散射范围(2θ_(CuK_α)=5°—140°)。通过对分离出来的表征非晶区分子链间分布的非晶主峰特征参数的分析,探讨了在特定拉伸条件下非晶区分子取向在成膜过程的变化。     

半结晶聚酯的两相分离及其可靠性分析

联用Rietveld方法、Fourier过滤技术和径向分布函数(RDF)研究了半结晶聚酯(PET)粉末样的结晶相和非晶相两相分离及结构分析问题，得到合理的结晶相和非晶相的结构参数，表明这种方法对分析半结晶高聚物的两相结构是可行的.文中提出，判断半结晶高聚物二相分离和结构分析是否可靠，除需考虑分辩结晶相结构参数是否正确的三个判据之外，还需加上二个物理判据.还指出 ,若要获得合理的两相分离结果，提供纯非晶试样的散射曲线作为拟合时本底强度初始值是必要的.     

电化学微/纳加工分辨率的影响因素及对策

The etching resolution of electrochemical fabrication technique is influenced significantly by the diffusion layer of the etchant. It has been shown that a fast etching rate can achieve higher etching resolution due to so-called heterogeneous scavenging effect, while a lower etching rate will result in rather lower etching resolution. For the latter case, the confined etchant layer technique(CELT) has been employed to improve the etching resolution. i. e., a certain redox couple which can consume the etchant homogeneously and rapidly was added to the solution. The homogeneous scavenging effect confined the etchant within a narrow layer around the electrode surface and much improved etching resolution was achieved. Using the CELT and a needle-shaped microelectrode, an etching spot of several micro-meters was obtained at silicon wafer surface.     

石墨炉原子吸收光谱测定加热不燃烧烟烟草材料中铅含量的不确定度评定

为评价石墨炉原子吸收光谱法(GF-AAS)测定加热不燃烧烟(HNB)烟草材料中铅含量检测方法的可靠性和检测结果的准确性,采用自下而上法(bottom-up)评定铅含量检测结果的不确定度,分析了测量不确定度的来源及各不确定度分量的影响程度.结果表明,加热不燃烧烟烟草材料中铅含量为2.02 mg/kg,扩展不确定度为0.26 mg/kg(k=2).测量不确定度主要来源于标准曲线拟合和仪器稳定性.故选择适宜的试验方案及试剂,设置合适的仪器参数,确保良好的仪器状态及性能,是获得准确检测结果的前提条件.     

离子交换树脂催化合成氯乙酸甲酯

本文以强酸型阳离子交换树脂为催化剂合成氯乙酸甲酯．研究了催化剂种类、催化剂用量、物料配比、催化剂使用次数及反应时间对反应的影响．实验结果表明，００１×７阳离子交换树脂催化效果较佳．该方法具有催化活性好，催化剂可循环使用和避免波硫酸污染的特点，转化率可达９３～９４％．