正丁醇萃取-稀盐酸溶解原子荧光光谱法间接测定中草药中钼

建立了正丁醇萃取稀盐酸溶解原子荧光光谱法间接测定中草药中钼的方法。基于As(Ⅴ)和钼酸铵在浓度为0.3 mol·L-1硫酸介质中能形成砷钼杂多酸,且该杂多酸可以被有机试剂萃取,萃取后蒸干有机试剂,残渣用稀盐酸加以溶解,原子荧光光谱法间接测定钼的含量。在优化的实验条件下,钼的含量在0～15 μg·L-1范围内呈良好的线性关系。方法的检出限是0.44 μg·L-1, 相对标准偏差1.1%。据此对中草药样品进行分析,平均加标回收率介于95.6%～101.3%之间。     

离子交换富集-ICP-OES测定沉积物中痕量钼

建立了以717型强碱性阴离子树脂富集-电感耦合等离子体-发射光谱法测定沉积物样品中痕量钼的分析方法,优化了各项仪器条件、化学条件及操作参数。并考察了共存离子的干扰。本法测定钼的检出限为0.09μg/L,回收率在98.2%—105.9%之间,方法应用于沉积物样品中微量钼的测定,获得满意的结果。     

阻抑动力学光度法测定煤中的痕量钼

基于在硫酸介质中,痕量钼（Ⅵ）阻抑高碘酸钾氧化溴酚蓝的褪色反应,建立了阻抑动力学光度法测定痕量钼的新方法。研究了反应的最佳条件,测定了反应动力学参数。方法的线性范围为0—0.050μg.mL-1钼（Ⅵ）,检出限为3.85×10-10g.mL-1,相对标准偏差小于7.0%。用于煤样中钼的测定,结果满意。     

ICP-MS快速测定土壤、水系沉积物样品中的28种元素

建立一种对土壤、水系沉积物样品中的15种稀土元素分量以及锂、铍、钛、锰、钴、铷、锶、钼、镉、铯、钨、铊、铀等28种元素进行同时快速测定的方法.样品用氢氟酸、硫酸分解处理后,用电感耦合等离子体-质谱仪进行测定.通过测试3件土壤及3件水系沉积物国家标准物质对方法的准确度和精密度进行考核,28种元素测试值与推荐值吻合.     

催化动力学光度法测定微量钼——钼(Ⅵ)-硫酸肼-甲苯胺兰体系

本文研究了在硫酸介质中,微量钼(Ⅵ)催化加速硫酸肼还原甲苯胺兰褪色及动力学条件,建立了催化动力学光度法测定微量钼(Ⅵ)的方法。其检出限为5.154×10     

原子吸收光谱法间接测定钼精矿中钼的研究（英文）

对于钼精矿中钼的测定,标准方法采用钼酸铅重量法,该方法需要将钼酸铅沉淀反复多次洗涤、过滤,以保证沉淀物中夹带的铅离子洗涤完全,再对沉淀物进行灰化、灼烧等多步操作,步骤较繁琐,分析费时,不能快速配合选矿、冶金的科学研究。应用原子吸收光谱法间接测定钼,建立了钼精矿中钼的快速分析方法。钼精矿样品经硝酸、氯酸钾、硫酸加热溶解后,用酚酞和盐酸调节pH值,加入乙酸-乙酸铵缓冲溶液调节pH值至5~7,再加入一定量且过量的铅标准溶液。基于在室温下,钼酸铅为难溶电解质,难溶电解质在一定温度下能否沉淀完全,通常比较离子积Q_c与溶度积常数K_(sp)的相对大小,当Q_cK_(sp),溶液过饱和,沉淀物完全析出,钼精矿中钼的含量为40~60%,铅的加入量为0.125 0~0.150 0 g,取最小值计算出溶液中钼酸铅的离子积,Q_c=[Pb~(2+)][MoO_4~(2-)]=2.51×10~(-5),K_(sp)=1.0×10~(-13),QcK_(sp),因此钼酸铅沉淀可以完全析出,待钼酸铅沉淀完全后干过滤,用原子吸收光谱法测定滤液中过量的铅离子,用差减法计算得出钼精矿中钼的含量。文中分别考察了乙酸-乙酸铵缓冲溶液的加入量及其浓度、铅标准溶液的加入量、钼酸铅沉淀完全的时间、加热时间以及常见共存离子如W~(6+),Sn~(4+)和Cu~(2+)等的最大允许量诸多因素对原子吸收光谱法间接测定钼的影响。与钼酸铅重量法相比,该方法省去了对钼酸铅沉淀反复多次的洗涤、灰化以及灼烧等步骤,操作简便易掌握,分析时间缩短一半,并用钼酸铅重量法与本方法进行对照实验,分析结果进行数理统计,得出结论:本方法具有很好的准确度和精密度,可用于选矿、冶金钼精矿样品中钼的快速分析检测。     

HG-AFS测定铅-锑合金中的硒

建立氢化物发生-原子荧光光谱法测定铅-锑合金中硒的分析方法。试样经33%硝酸和酒石酸溶解,硫酸沉淀分离基体铅元素,在40%盐酸介质中直接测定样品中的硒。考察了测定的最佳条件、铅及共存元素对测定的影响。两个标样的方法相对标准偏差为分别为6.52%—9.34%。准确度和精密度均能满足分析需要,具有较强的实用性。     

石墨炉原子吸收光谱法快速测定小麦中的钼

采用全热解石墨管和快速消化样品,建立了高灵敏、快速测定粮食中微量钼元素的方法。该法适用于大批量样品的分析。     

新的极谱催化体系连续测定岩溶地下水中钨和钼

钨、钼-二苯基乙醇酸-2,2′-联吡啶-钛铁试剂连测体系还未见报道。本文提出了在0.05mol/L的硫酸中,钨与二苯基乙醇酸,2,2′-联吡啶的络合物在-0.79V(vs.SEC)产生一个极其灵敏的极谱催化波,测定完钨后,加入少量钛铁试剂测定钼。钼于-0.20V(vis.SEC)处产生极灵敏的阴极化导数波,波形尖锐对称,易于测量。采用此种连测体系,钨钼的灵敏度都可满足要求,钨和钼的检出限分别为0.004、0.01μg/L。确定最佳条件和拟定了不经分离富集直接测定岩溶地下水中痕量钨和钼的方法。此外还对极谱波性质进行了探讨,讨论了阴、阳离子表面活性物质对极谱催化波的作用机理。     

原子吸收光谱法间接测定钼精矿中钼的研究

对于钼精矿中钼的测定,标准方法采用钼酸铅重量法,该方法需要将钼酸铅沉淀反复多次洗涤、过滤,以保证沉淀物中夹带的铅离子洗涤完全,再对沉淀物进行灰化、灼烧等多步操作,步骤较繁琐,分析费时,不能快速配合选矿、冶金的科学研究。应用原子吸收光谱法间接测定钼,建立了钼精矿中钼的快速分析方法。钼精矿样品经硝酸、氯酸钾、硫酸加热溶解后,用酚酞和盐酸调节pH值,加入乙酸-乙酸铵缓冲溶液调节pH值至5～7,再加入一定量且过量的铅标准溶液。基于在室温下,钼酸铅为难溶电解质,难溶电解质在一定温度下能否沉淀完全,通常比较离子积Q_c与溶度积常数K_sp的相对大小,当Q_c>K_sp,溶液过饱和,沉淀物完全析出,钼精矿中钼的含量为40～60%,铅的加入量为0.125 0～0.150 0 g,取最小值计算出溶液中钼酸铅的离子积,Q_c＝[Pb2+][MoO2-₄]=2.51×10-5,K_sp＝1.0×10-13,Q_cK_sp,因此钼酸铅沉淀可以完全析出,待钼酸铅沉淀完全后干过滤,用原子吸收光谱法测定滤液中过量的铅离子,用差减法计算得出钼精矿中钼的含量。文中分别考察了乙酸-乙酸铵缓冲溶液的加入量及其浓度、铅标准溶液的加入量、钼酸铅沉淀完全的时间、加热时间以及常见共存离子如W6+,Sn4+和Cu2+等的最大允许量诸多因素对原子吸收光谱法间接测定钼的影响。与钼酸铅重量法相比,该方法省去了对钼酸铅沉淀反复多次的洗涤、灰化以及灼烧等步骤,操作简便易掌握,分析时间缩短一半,并用钼酸铅重量法与本方法进行对照实验,分析结果进行数理统计,得出结论：本方法具有很好的准确度和精密度,可用于选矿、冶金钼精矿样品中钼的快速分析检测。     

M?ssbauer characterization of joints of steel pieces in transient liquid phase bonding experiences

Joining of seamless, low carbon, steel tubes were performed by means of Transient Liquid Phase Bonding process employing a foil of Fe-Si-B metallic glass as filler material. The influence of the main parameters of the process was evaluated: temperature, holding time, pressure and post weld heat treatment. Powder samples were obtained from the joint of tubes and characterized employing M?ssbauer Spectroscopy in transmission geometry. The sampling was performed both in tubes successfully welded and in those which show joint defects. The results obtained are correlated with the obtained microstructure and the diffusion of Si and B during the process.     

Assembly structure convective—flow CO laser

This article describes a convective-flow CO laser composed of quartz tubes, nickel–chromium steel components, a copper heat exchanger, polytetrafluoroethylene tubes and other components. The method of vacuum sealing between quartz tubes and nickel–chromium steel pipes by polytetrafluoroethylene tubes enables the laser to operate with liquid nitrogen cooling. An output of 120 W has been obtained by adopting a non-selective cavity.     

鳍片管束撞击式气固分离器的试验研究

本文提出了一种应用于循环流化床，兼有强化传热的鳍片管束惯性分离器。试验表明此分离器具有高效、低阻、结构紧凑等优点，特别是它能强化换热，同时在管内工质冷却下鳍片能保持较低温度，因而能使用普通锅炉用钢。本文通过试验研究了这一分离器的流动结构、分离性能及有关设计参数的选择。     

分离式热管换热器传热特性的实验研究

本文在自行设计分离式热管实验装置的基础上,对其传热特性进行了实验研究。其工作温度为170～250℃,热流密度为25～50 kW/m~2。蒸发段和冷凝段构成相同,均是由7根直径30 mm的无缝钢管短管束组成,管长为160 mm,带有紧套的钢帛环形肋片结构尺寸为:外径45 mm、厚1 mm、片间距4 mm。实验结果表明,在本实验条件下,分离式热管的最佳充液率按管束总容量计为18%～38%。根据实验结果拟合了最佳充液率(24%)下蒸发段内部平均沸腾换热系数和冷凝段内部凝结换热努塞尔数综合关系式。     

The use of laser-induced plasma spectroscopy technique for the characterization of boiler tubes

The present work focuses on the characterization of boiler tube walls using laser-induced plasma spectroscopy technique with visual inspection by optical and scanning electron microscopy of the cross-sections of these tubes. In a watertube boiler, water runs through tubes that are surrounded by a heating source. As a result, the water is heated to very high temperatures, causing accumulation of deposits on the inside surfaces of the tubes. These deposits play an important role in the efficiency of the boiler tube because they produce a reduction of the boiler heat rate and an increase in the number of tube failures. The objectives are to determine the thickness and arrangement of deposits located on the highest heat area of the boiler and compare them with tube parts where the heat flux is lower. The major deposits found were copper and magnetite. These deposits come mainly from the boiler feedwater and from the reaction between iron and water, and they do not form on the tube walls at a uniform rate over time. Their amount depends on the areas where they are collected. A Nd:YAG laser operating at 355 nm has been used to perform laser-induced plasma spectra and depth profiles of the deposits.     

高钢级管线钢中锰分析方法研究

高钢级管线钢可以有效提高管道长距离运输天然气的安全性并能减少成本,将成为未来输气管道工程的主要用钢.本文基于过硫酸铵对锰(Ⅱ)的氧化作用,建立了过硫酸铵直接氧化分光光度法测定高钢级管线钢中锰的方法.采用硫酸-磷酸混合酸溶解试样,于加热下用过硫酸铵作为氧化剂,以硝酸银为催化剂,将锰(Ⅱ)氧化成锰(Ⅵ)进行吸光度测定,本法采用不同锰含量的标钢溶液绘制工作曲线,这样更接近于真实样品,实验表明,该方法准确、简便、成本低,具有实用和推广价值,并以此方法成功测定了高钢级管线钢样品中的锰.     

Study on Laser Visual Measurement Method for Seamless Steel PipeStraightness Error by Multiple Line-structured Laser Sensors

An original non-contact measurement method using multiple line-structured laser sensors is introduced for seamless steel pipe straightness error is in this paper. An arc appears on the surface of the measured seamless steel pipe against a line-structured laser source. After the image of the arc is accepted by a CCD camera, the coordinates of the center of the pipe cross-section circle containing the arc can be worked out through a certain algorithm. Similarly, multiple line-structured laser sensors are equipped parallel to the pipe. The straightness error of the seamless steel pipe, therefore, can be inferred from the coordinates of multiple cross-section centers obtained from every line-structured laser sernsor .     

高性能管线钢中镍分析方法研究

用盐酸-硝酸混合酸溶解试样,以酒石酸钠掩蔽铁,氢氧化钠强碱性介质中,过硫酸铵为氧化剂,镍与丁二酮肟生成酒红色络合物,用吸光光度法测定高性能管线钢样品中镍,吸光度与镍含量在0.076%—0.66%范围内呈线性关系。采用不同镍含量的标钢溶液建立校准曲线。并测定了X-100、X-80及X-70钢级管线钢中的镍,结果满意。该方法准确、简便、成本低,具有实用和推广价值。     

Study on Laser Visual Measurement Method for Seamless Steel Pipe Straightness Error by Multiple Line- structured Laser Sensors

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Micro-segregation model calculation of residual tin in boiler and pressure vessel steel

Tin is a typical residual element in steel and mainly originates from Sn-containing complex iron ore and steel scrap. The segregation of Sn in steel is harmful to the performances of steel. In this paper, the micro-segregation of residual element Sn during the solidification process of boiler and pressure vessel steel by micro-segregation model was studied. The results showed that the micro-segregation degree of Sn reduces apparently with the increase of cooling rate and remarkably deteriorates during the solidification process. When the initial content of C is higher than 0.1%, it will cause the solidification transform of the solid phase converting from the ferrite phase to austenite phase and the significant increase in the micro-segregation degree of Sn. However, increasing the initial contents of Si, Mn, P and S separately has non-significant effects on the micro-segregation degree of Sn. In addition, the improvement of initial content of Sn will lead to the micro-segregation degree decrease of Sn and has an inapparent impact on zero strength temperature and zero ductility temperature of the boiler and pressure vessel steel.