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焊缝缺陷超声波定量检测方法探讨 总被引:4,自引:0,他引:4
本文以常规超声检测方法定量焊缝块陷自身高度,通过理论分析和实验测定,分别找出了相对灵敏度法。端点反射法,端部反射法的适用范围和优缺点,解剖实测结果表明,对危害性缺陷,在99.7%可靠性下,测定误差分别达到49.3%,23.9%,20.8%,能够保证压力容器安全分析和缺陷监护控制的工程需要 相似文献
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研究了比色法测定YG类硬质含金中微量钛的测定条件,建立了分析方法。方法的相对标准偏差为6%左右,最低检出限为1ppm. 相似文献
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稀土Y对纳米粉90W-Ni-Fe合金性能和微观结构的影响 总被引:1,自引:0,他引:1
采用SEM和金相仪器对添加不同Y量的纳米粉90W-7Ni-3Fe合金试样断口进行形貌观察和W晶粒测试:并对烧结态试样的相对密度、抗拉强度、延伸率等性能进行测定与分析。结果表明:当Y量在0.2%~0.6%(质量百分数,下同)时,试样相对密度为99.2%~99.6%,抗拉强度为1000MPa-1100MPa,延伸率为16%-19.5%:添加0.4%Y后,W晶粒从原来的20μm~25μm减小到12μm,W晶粒形状由不加稀土时的球形变为近球形或多边形。添加0.4%Y后,在界面上形成了W13.07Ni2.96Fe1.52Y23.65Ox(摩尔数比)的中间相,其阻止了W原子在粘结相中的扩散,阻止了W晶粒长大,细化了W晶粒,提高了合金的性能。 相似文献
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活性炭吸附-电感耦合等离子体发射光谱法测定化探样品中痕量金铂钯 总被引:18,自引:1,他引:18
对于大量化探样品的测定,方法必须尽量操作简便、程序快捷、成本经济和结果可靠。本方法采用酸溶分解样品,活性炭吸附分离富集Au,Pt,Pb,结合电感耦合等离子体发射光谱法进行测定。方法的检出限为0.2ng/g(Au,Pb)-0.5ng/g(Pt),用于化探样品的测定,结果与推荐值吻合较好,5次平行测定的RSD在6.5%-13.5%。方法简便快速,能适合大量化探样品的实际分析。 相似文献
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验证并分析了Ag-DDTC光度法测定微量砷时锑的干扰及消除情况,试验表明,测定钢铁中微量砷时,小于80μg锑不干扰测定;80-300μg锑干扰测定;大于300μg锑严重干扰测定。控制硫酸介质酸度在0.75-1.50mol/L之间,酒石酸(50%)、碘化钾(30%)和氯化亚锡(20%)用量分别为3.0mL、2.5mL和2.0mL时,锑25倍于砷时对测定无影响。 相似文献
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采用发射光谱载体分馏法测定WO3中Zn、Zr、Sr、Ba、Ag的含量.试验中,选择了含3.5%氟化锂、4.0%碳酸锂的石墨粉作缓冲剂,选择了适宜的分析线和光谱测定条件.测定下限分别为:Zn、Zr0.001%,Ba0.0007%,Sr0.0005%,Ag0.0002%. 相似文献
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ZHAO Guohu ZHAO JunBasic Science Department Gansu Agricultural University Lanzhou China 《稀有金属(英文版)》2002,21(4):255-259
A spectrofluorimetric method has been developed for the determination of terbium(III) based on the formation ofa complex with terephthalic acid [benzene-1,4-dicarboxylic acid (TPA)] in slighdy acidic aqueous solution in the presenceof gelatin. Terbium ion can form a stable complex with TPA with the stoichiometry of 1:2. The best excitation and maxi-mum emission wavelengths are observed at 260 nm and 545 nm, respectively. The fluorescence intensity of terbium com-plex gets the strongest within 20 min and remains stable up to 10 h, and it is proportional to terbium(III) concentration in therange of 4.0×10-5-1.6×10-7 mol·L-1 under the optimum conditions. The fluorescence system has good selectivity, sensitivityand stability. The relative standard deviation is still within ±4% in the presence of 1200-fold amounts of the other lanthanideions when the concentration of terbium(III) is 1.0×10-6 mol·L-1 and common co-existing ions hardly interfere the determi-nation. It has been applied to the direct fiuori 相似文献
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本文提出了电感耦合等离子体发射光谱法直接测定Si3N4粉中微量元素Fe、Al、Ca含量的分析方法。进行了样品分解试验,考察了基体对测定元素的影响以及各元素间的相互干扰情况,优化了分析条件,各元素的相对标准偏差均在5%以下,回收率为94%~102%。 相似文献
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氢化发生ICP-OES测定高纯氧化铌中铋、硒、碲量 总被引:1,自引:0,他引:1
提出了氢化发生电感耦合等离子体发射光谱法(HG-ICP-OES)测定高纯氧化铌中铋、硒、碲的分析方法。优化了氢化条件,选择了最佳仪器参数,研究了氧化铌基体对氢化物测定的影响。铋、硒、碲的检出限分别为0.1、0.2、3μg/g,加标回收率为90%~120%,相对标准偏差小于10%。 相似文献
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M. Palm C. He O. Dovbenko F. Stein J. C. Schuster 《Journal of Phase Equilibria and Diffusion》2012,33(3):210-221
By metallographic observation of the as-cast microstructures, determination of the liquidus temperatures and the temperatures of invariant reactions by differential thermal analysis, and measurement of the compositions of the primary phases and the eutectic residuals by electron probe miroanalysis, a liquidus projection for the Co-Al-Nb system has been established for the first time. The binary Co-Nb intermetallic phases have a large solid solubility for Al and their melting temperatures increase markedly by the addition of Al. The only ternary compound, the Heusler phase NbCo2Al, melts incongruently at about 1485?°C. By CALPHAD modelling the consistency of the experimental data has been checked. Calculated and experimentally determined temperatures of the invariant reactions are in good agreement and are summarised within a reaction scheme. 相似文献
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none 《腐蚀工程科学与技术》2013,48(3):128-130
AbstractAn empirical equation has been derived for quantitative determination of the contribution by different chemical and physical factors towards the total cracking time in the stress corrosion cracking of copper-manganese alloys in Mattsson's solution. Three alloys containing 3·9 to 8·1 % of Mn, showing intergranular cracking, have been studied at different pH and copper concentrations of the solution and the results were used for the formulation of the equation. Cracking times calculated from the proposed equation for any set of variables were shown to correspond well with the observed values within allowable limits of deviation. 相似文献
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分析了金属催化转化器在汽车行业的市场前景和行业管理现状。针对车用金属催化转化器样品,建立了用ICP-MS法测定催化剂涂层中贵金属Pt、Pd、Rh含量的方法。采用6 mol/L盐酸溶液浸泡样品,将得到的滤液与不溶物分别经过碲共沉淀制备成试液。经过8家实验室的共同验证:本方法对于Pt、Pd、Rh 3种元素,各试验室的样品测定结果与参考值的相对偏差均小于10%,再现性不确定度分别为:6.6%、6.5%、5.8%,本方法检出限低,回收率高,再现性好,可行性强。 相似文献