烟碱-磷钼杂多酸缔合微粒体系的光谱研究及分析应用

采用分光光度法和共振散射光谱法研究了小烟碱一磷钼杂多酸缔合微粒体系．在波长300～800nm范围内,波长愈短缔合微粒体系的吸光度值愈大,在400nm处的吸光度与烟碱浓度在0．50-50．0μg／mL范围成良好线性关系,检出限(3σ)为0．1μg／mL．据此建立了一个测定烟草中烟碱含量的分光光度法．该法灵敏、简便、快速、准确、重复性好,平均回收率为99％～103％,相对标准偏差RSD为0．9％～1．3％．共振散射光谱研究结果表明,该体系存在烟碱-磷钼杂多酸缔合微粒,该微粒在420nm处存在共振散射效应．     

两步法制备多孔硅及其表征II：脉冲电流法

采用脉冲阳极／阴极电流和化学氧化两步法分别在1：1的氢氟酸和乙醇溶液中及20％硝酸溶液中制备出孔径约为0．5－3μm,厚度大约为10－20μm的多孔硅样品,将获得的多孔硅结构再进一步用扫描电子显微镜和拉曼光谱仪进行表面形貌和光学性质的考察,与恒电流－化学氧化两步法制得的多孔硅相比,用脉冲电流法得到的多孔硅的孔径范围较大,且多孔层较厚,制备时加紫外光照显著提高了多孔硅的,并发生“蓝移”现象,用脉冲电流法制得的多孔硅在老化后（在干燥器放置一年）同样观察到光致发光明显增强。     

电感耦合等离子体发射光谱法测定硅铝铁合金中的多种元素

本文应用电感耦合等离子体发射光谱法(ICP—AES)对硅铝铁合金的溶解和仪器参数进行了优化,确定了适宜的硅铝铁合金中多种元素的测定条件。测定结果的RSD在0．26％～5．1％之间,加标回收率在95．5％～102．7％之间,标准样品测定结果与推荐值接近。本文方法简便、准确、快速,有应用推广价值。     

高效液相色谱-电喷雾三级四极杆质谱测定鸡肉组织中氯霉素残留的研究

建立了鸡肉组织中氯霉素残留的液相色谱-电喷雾质谱联用(LC—ESI—MS—MS)测定法。采用微量化前处理方法,省去固相萃取步骤,以m／z321．0为母离子,m／z152．1、257．0和194．1为子离子,采用多反应监测(MRM)负离子模式对鸡肉组织中的氯霉素残留进行检测、方法的检出限为0．010μg／kg(S／N≥3),定量下限为0．10μg／kg,线性范围为0．100～1．00μg／L,加标回收率为74．3％～84．0％,相对标准偏差(n=6)为7．9％～12．7％。该法具有操作简便、有机试剂消耗量少、测定周期短等优点。     

微肥中锌的双硫腙螯合微粒共振散射光谱分析

在pH9．0的NH3—NH3-Cl缓冲溶液中,Zn(Ⅱ)与双硫腙可形成能稳定存在的螯合物微粒,显示出共振散射效应．该微粒体系的最强共振散射峰在605nm处,锌的浓度在0．02～1．54μg／mL范围内与共振散射强度(J605nm)呈线性关系,检出限为0．008μg／mL Zn．利用共振散射测量微肥中微量元素锌,方法简单、灵敏度高、重现性好,结果满意。     

蒸馏分离-分光光度法测定枸杞子中的微量锗

利用盐酸与锗元素反应生成易挥发的四氯化锗，以蒸馏方法将四氯化锗分离出来，然后在1～1．5mol／L盐酸溶液中，用显色剂苯芴酮与四氯化锗进行显色反应生成橙红色配合物，在500nm波长处进行分光光度法测定。在0～200μg／(50mL)，线性方程为A=0．1714c．相关系数r=0．9996。该方法的检出限为0．0588μg／mL，测定结果的相对标；位偏差为2．24%～2．30%(n=11)，平均回收率为95．3％～95．4％。     

活性炭微柱在线流动注射预富集-火焰原子吸收快速顺序测定铜、钴、镍、镉、铅的研究

采用双柱富集的流动注射在线预富集系统与220FS顺序多元素原子吸收分光光度计联用，使用圆锥型活性炭微柱为预富集柱，在pH4～5．5范围内，以吡咯啶二硫代氨基甲酸铵(APDC)为络合剂，6mol／L HNO3为洗脱剂，实现了Cu、Co、Ni、Cd、Pb5种元素的快速顺序测定。该体系对以上5种元素的富集倍数为9．8～15．5之间，34s富集的检出限(3σ)Cu为1．81，Co为3．10，Ni为1．66，Cd为0．28，Pb为4．90μg/L；相对标准偏差Cu 1．13％；Co1．24％；Ni2．26％；Cd0．95％；Pb1．77％。     

气相色谱-质谱法同时测定番茄制品中拟除虫菊酯类农药残留

番茄制品经乙腈提取,盐析,氟罗里硅土固相萃取小柱净化,微池电子捕获检测器(μECD)负化学源质谱(NCI—MS)并联对净化液进行检测,一次进样可对番茄制品中的9种拟除虫菊酯类农药残留准确定量和确证。μECD回收率为87．6％～107．0％;相对标准偏差为5．5％～11．3％;检出限为0．0005～0．005mg／kg;负化学源选择离子(NCI-SIM)模式回收率为91．9％～109．7％;相对标准偏差为5．2％～12．7％;检出限为0．0005～0．005mg／kg(氯菊酯除外),两者之问没有显著的差别。该法快速、灵敏、准确,各项技术指标均满足农药残留检测的要求。     

反相微乳液化学剪裁制备明胶-γ-Fe2O3纳米复合微粒

用反相微乳液化学剪裁技术制备了明胶包裹的复合 γ-Fe2 O3纳米量级超细微粒 .XRD、TEM、EDS、SEM和 IR测试表明 ,微粒为明胶包裹球形超细微粒 .微球的粒径为 1 .2～ 3 .2 μm,平均粒径约 2 .6μm,而微粒的粒径为 1 5 nm.每个复合微球中约有 80～ 2 1 3个氧化铁粒子 .该复合微粒的比饱和磁化强度 3 0 .3 44π ×1 0 3A/ m,矫顽力 Hc=62 0 7A/ m,剩磁 Br=2 .944π × 1 0 3A/ m.具有硬磁体的性质     

SAPO-5分子筛的可控合成及晶化过程探索

在非醋酸体系下分别通过动态和静态水热晶化方法合成了SAPO-5分子筛,并考察了转速、晶化时间及凝胶体系水硅比对SAPO-5分子筛晶相及形貌的影响,采用X射线衍射(XRD)和扫描电子显微镜(SEM)技术研究了静态、动态水热条件下SAPO-5分子筛的晶化过程.结果表明,静态水热条件下晶化6 h得到的SAPO-5分子筛为球状、六边形柱状聚集晶体;而在20 r/min转速下晶化2和6 h得到的SAPO-5分子筛分别为分散的凹面柱状晶体(凹面直径约6～8μm)及均一分散的球状晶体(直径为16μm);在60 r/min转速下晶化3 h即可得到高度分散的六边形柱状晶体(六边形直径约5～8μm);提高转速至100和140 r/min时仅需晶化1 h即可得到六边形柱状晶体.通过考察体系水硅比(H₂O/Si摩尔比)的影响,确定最佳的水硅比为70,此条件下所得晶相为纯相且分子筛的分散度最好.综上可知,相较于静态晶化,动态晶化不仅从形貌上改善了晶体的分散度,通过缩短晶化时间、降低晶化转速也提高了SAPO-5分子筛的晶化效率.本文采用较小的水硅比(H₂O/Si摩尔比为...     

扫描电子显微镜与扫描隧道显微镜联用装置

在ＫＹＫＹ－１０００Ｂ型扫描电子显微镜上所开发的与其联用的袖珍型扫描隧道显微镜主要有四个部分：（１）减震阻尼装置,（２）隧道探针,（３）探针扫描与逼近装置,（４）电子控制与图象采集系统。它的分辨率约为１ｎｍ,并用它观察了半导体光栅与硅上金膜的细微结构。     

扫描电子显微镜对样品的要求及样品的制备

扫描电子显微镜对样品的要求很严,要求样品必须是固体,且做到五无:无毒、无放射性、无污染、无磁、无水分,成分稳定,块状样品大小要适中,粉末样品要进行特殊处理,对不导电和导电性能差的样品要进行镀膜,且要选择适当的镀膜仪,方能达到理想的分析效果.     

Imaging and Analysis of Surfaces with a Scanning Electron Microscope and Electron Spectrometer

The topography and the composition of a surface are in many cases of equal importance (catalysis, electroplating, pretreatment of foils and sheet metal, corrosion, passivation, adsorption, coating of fibers, etc.), and this explains the great interest in methods of investigation that reveal both. If the demands on the resolving power, the analytical possibilities, and the thickness of the surface layer are not too exacting, combined devices like the scanning electron microscope and its analytical accessories can be used. When it is necessary to avoid the compromises involved in simultaneous imaging and analysis, the investigations must be carried out with separate equipment. As an example of a method for the analysis of surfaces we consider briefly photo- and Auger electron spectroscopy (ESCA).     

充分发挥分析电镜的作用

作者积多年电子显微工作之经验，总结出熟悉仪器、不断改进实验方法和能够自行进行常规维修是做好电子显微工作的关键。广泛宣传，和用户深入地讨论并教会更多人操作仪器，使他们的科研与生产少走弯路，分析工作才能取得明显的社会和经济效益。     

Orientation Imaging Microscopy for the Transmission Electron Microscope

The resolution limit of Orientation Imaging Microscopy in the Scanning Electron Microscope is between 20 nA and 80 nA depending on the basic resolution/beam current performance of the SEM, the sample atomic number and the level of residual strain within it. The newer technique of orientation imaging in the transmission electron microscope, TEM, improves on this resolution limit by a factor of five to ten. The new technique is based on a novel procedure for determining the crystallography of separate small volumes in the sample by examination of a large series of dark field images. Each image is recorded for a different diffraction condition. This is achieved by using a computer to direct the electron beam onto the same area of the sample so that it covers all directions within a cone of semi-apex angle 3 degrees. Analysis of the intensity of the same point in each of the dark field images permits reconstruction of a diffraction pattern for that point providing the data to calculate its crystal orientation. The process is repeated for each point in the image. The Orientation Image Micrograph is constructed from the orientations so determined. The technique is shown to be capable of producing orientation micrographs of high spatial resolution for unstrained samples. For highly strained samples difficulties are encountered in accurately indexing the complicated diffraction patterns that are observed. Methods to improve the indexing procedures involve determining the sub-cell structure first from a comparison of patterns from adjacent pixels and then summing all patterns belonging to a single sub-cell. The resultant improvement in pattern quality permits more reliable determination of orientation. Examples of this procedure are taken from studies of deformed aluminum.     

扫描电子显微镜运行和管理的实践与探索

扫描电子显微镜常用于观察样品的内部结构以及化学组成,是材料学领域不可缺少的现代分析测试仪器. 绍兴文理学院使用扫描电子显微镜已十多年,年平均运行有效机时在1 000 h以上,是学校利用率最高的仪器设备之一. 结合大型仪器设备管理运行中的经验以及目前存在的一些问题,从检测技术提升、仪器共享、评价体系等方面对仪器的管理制度进行探讨.     

Latex Film Formation in the Environmental Scanning Electron Microscope

Summary: Environmental scanning electron microscopy (ESEM) was used to study the film formation mechanisms and extent of coalescence of three acrylic latex compositions with different glass transition temperatures (T_g), here defined as standard-low T_g, standard-high T_g (both carboxymethyl cellulose- stabilised) and novel (stabilised with a novel polysaccharide derived from agricultural waste). The ESEM analysis revealed that the microstructure of the standard – low-T_g system consisted of individual particles in dispersion and upon evaporation a continuous film formed, whereas in the case of the standard - high T_g latex particle deformation was not observed, but particle aggregation resulted in the formation of crystal-like structures that have formed via the formation of stacking faults. However, in the case of the novel system the microstructure consisted of individual particles and clusters and during evaporation a discontinuous film formed with voids present within its structure and some of the clusters accumulating on the surface of the specimens.     

扫描电镜非最佳条件操作考察

扫描电镜在非最佳的条件下工作仍能获得有用的信息,尤其是样品导电性差,又不便喷金,还要尽可能将样品原来的面貌保存下来取得高质量照片的时候,其效果显著．