计算原子吸收法间接测定钒

本文研究了用空气－乙炔火焰原子吸收法间接测定钒一种计算分析方法，利用钒对原子吸收法测定铬时的干扰效应，以多项式作为表面其干扰效应的数学模型，在已知铬含量的铬钒混合液中测定铬的吸光度，并从数学模型中解出钒的浓度，从而间接测定了钒。     

空气－乙炔火焰原子吸收测定铬时某些化学干扰的计算消除方法

本文研究了空气－乙炔火焰原子吸收法测定铬时某些化学干扰的计算消除方法，用多项式作为表达铬和干扰元素间相互关系的函数式。经测定钴－钛，铬－铁和铬－钒干扰对混合液中铬的含量，表明计算法能较好地消除铁、钴、钒对测铬的干扰效应。     

ICP—AES法同时测定粉煤灰中14种元素

煤灰中多种元素的ICP-AES测定国内外文献已有报导。本文应用高压消解器的低温高压消解技术处理粉煤灰试样,用数学校正法修正干扰用不去溶ICP-AES法分析测定了其中的铜、锌、铅、磷、铬、镍、钛、钒、钡、锰、钴、铍、钼、锶等十四种元素。     

密闭空间空气中24种金属气溶胶的原子吸收光谱法测定

用原子吸收光谱法，一次采样，同时测定连续密闭１２昼的窨 空气中２４种金属气溶胶，即银、铝、钡、钙、镉、钴、铬、铜、铁、钾、镁、钼、钠、镍、铅、锑、硒、硅、锡、锶、钛、钒和锌。根据空间金属气溶胶的浓度、性质和原子化行为的不同。将样品分为四组，采用干法和湿法结合处理样品，同时测定，回收率在８８－１１０％之间，各元素间基本无干扰，测定结果与文献报道值相近。     

ICP-AES测定铝-钛-硼合金中的16种元素

电感耦合等离子体-原子发射光谱法(ICP-AES)测定铝-钛-硼合金中钛、硼、铁、硅、镓、铜、锶、锆、锌、镁、锰、镍、铅、钒、镉和铬等16种元素含量.对分析线的选择、铝基体的干扰,样品的预处理过程进行了探讨.经实验,方法的回收率在95%-110%之间,测定结果的相对标准偏差(n=6)在0.4%-3.0%之间.该方法准确...     

国家标准钼精矿中钼的测定方法探讨

对国家标准GB/T 15079.1-1994钼精矿化学分析方法钼的测定,确定了干扰元素钨、钒、铬等的消除方法;并将不溶残渣的处理由混合溶剂烧结改为氢氧化钠熔融,从而提高了方法准确度,扩大了使用范围。     

ICP-AES、石墨炉原子吸收光谱法及X射线荧光光谱法测定土壤中钒的比较

研究了土壤中钒的3种测定方法,ICP-AES、石墨炉原子吸收光谱法和X射线荧光光谱法.其中ICP-AES选用谱线V 311.1nm,用干扰系数法,干扰系数用多个土壤标样的标准值和测定值的最小二乘法来确定;石墨炉原子吸收光谱法用新、旧石墨管(热解涂层),加与不加基体改进剂(硝酸镁)分别进行测试;X射线荧光光谱法样品无需前处理、无需做校准曲线,测定前仪器用自带校正钢片单点法进行校正.通过测试结果的比较得出:ICP-AES测定土壤标样中的钒,精密度高,准确度好,适合土壤中钒的实验室分析;石墨炉原子吸收光谱法灵敏度过高(高一个数量级),信号稳定性较差,对高温元素钒的测定最好加硝酸镁机体改进剂消除基体干扰且每只石墨管分析次数不超过100次;X荧光光谱法较适合于野外监测或土壤样品无损检测,操作方便快速.     

APDC-MIBK萃取原子吸收光谱法测定水中痕量三价铬和六价铬

作者前文报导了DDTC-MIBK萃取原子吸收光谱法测定铬(Ⅲ)和铬(Ⅵ)。该法灵敏、准确,但在氧化和分离过程中,需引入其他试剂,增加了干扰成分。APDC-MIBK萃取体系曾用于铬(Ⅵ)含量的分析;H.Bergmann等报导了APDC-MIBK测定铬(Ⅲ)和铬(Ⅵ)的研究。以两份等量试样,在不同酸度和温度试验条件下,分别测定     

食盐中矿物元素的FAAS分析干扰及校正

本文研究食盐中矿物元素火焰原子吸收的分析干扰因素,讨论了背景干扰,氯离子干扰,钠离子干扰及其共存离子干扰的问题。测定商品食盐中钾,钙,镁,铜,锰,的,铅,镉,铬。实验结果表明：铬不适合本法。背景吸收仅干扰钾和镁和测定,１％氯离子浓度干扰钾的测定,１０％以上氯离子浓度干扰其他元素;     

表面活性剂增感效应火焰原子吸收光谱法测定铬和钼

在应用火焰原子吸收光谱法测定铬和钼时,加入浓度为0.5%和0.5%以上的阴离子表面活性剂十二烷基硫酸钠(SLS)可使铬和钼的吸光度增高几乎为原来的两倍。同时能够克服盐酸、硝酸和钒(Ⅴ)硅(Ⅳ)、铝(Ⅲ)、铁(Ⅲ)、锰(Ⅱ)、钙(Ⅱ)、钾(Ⅰ)、和钠(Ⅰ)等十多种金属离子的干扰。进而讨论了测定铬时应用0.25%的非离子表面活性剂乙二醇辛基苯酚(OP-10)或triton X-100以及测定钼时应用0.6%的阳离子表面活性剂溴化十四烷基吡啶的增感效应及其克服干扰的情况,并与应用十二烷基硫酸钠作了比较。     

Mechanisms of radiation-induced surface composition modification in VCr alloys at high and low temperature

The effect of 0.5 to 3 keV argon ion sputtering on the surface composition of several alloys of vanadium and chromium has been investigated at temperatures in the range 300 to 950 K. At room temperature, sputtering depletes the alloys in chromium and the relative V/Cr sputter rate constant ratio is found to be 1.20, consistent with the ratio of the pure element sputter yields. Annealing clean alloys at temperatures in the range 550 to 670°C further enriches the surface in vanadium and also oxygen segregates to the surface. This behaviour is attributed to co-segregation of oxygen and vanadium, an interpretation supported by the observation of vanadium chemical shifts analogous to those observed in vanadium oxides, the depth profiles of the segregated surfaces and the bond energies in the VCrO system. Sputtering the alloys at temperatures in the range 410 to 620°C enriches the surface in chromium to a depth which increases with sputter annealing time. Similar behaviour has been reported on sputtering a V/Cr alloy at these temperatures but with much higher energy V⁺ ions, and has been attributed to radiation-induced segregation of chromium. The results presented in this paper offer a different interpretation. Annealing enriches the surface in vanadium which co-segregates with oxygen. Thus on sputter- annealing the surface will become depleted in vanadium at a rate which is probably enhanced by an increased sputter yield of VO over either V or Cr. This interpretation is further supported by the observation that the alloy is still depleted in vanadium when the sputtering occurs at room temperature when performed in a cycle with intervening annealing intervals.     

Quantitative AES of binary alloys: A comparison between handbook and pseudo-first principles corrections

Quantitative Auger electron spectroscopy of a number of binary alloys was studied. A pseudo-first principles correction scheme was applied to series of chromium/iron, chromium/nickel, and copper/gold alloys. Peak-to-peak height ratios of differentiated spectra were corrected for elemental differences in ionization cross section, Auger transition probability, atomic density, electron escape depth, backscattering factor, and sputter yield. These corrections changed the original ratio by factors ranging from 1.12 (for the chromium/iron series with a 10 kV primary electron beam) to 4.63 (for the copper/gold series with a 5 kV primary beam). The calculated surface concentrations were compared to wet chemistry bulk concentrations and in all cases, this first principles correction was an improvement over using uncorrected peak height ratios for concentration determination. For a $\text{50}\text{50}$ at% alloy in each series, the corrected data error for the chromium/iron alloy was 15%, for the chromium/nickel alloy was 2%, and for the copper/gold alloy was 36%. In all series except the chromium/iron system, concentrations obtained using this method had a smaller error than concentrations obtained using sensitivity factors from the Handbook of Auger Electron Spectroscopy.     

ESCA studies of Cr-Co alloys

ESCA examination of films formed on Cr-Co alloys after immersion in 0.1M NaCl for 24 h has shown that the thickness of passive films decreased with an increase in chromium content. Surface films consisted of chromium and cobalt oxides as Cr₂O₃ and CoO. The amount of CoO in the surface film of the alloy was decreased with an increase in chromium but Cr₂O₃ was found at a greater depth in the passive film at any composition. Cr₂O₃ was a major component of the surface film when the chromium content in the alloy was 10% or higher. Electrochemical techniques according to ASTM G59 and ASTM G5 were used for the determination of the relative corrosion rate. Both Co-10 wt.% Cr and Co-30 wt.% Cr alloys investigated showed a lower corrosion rate than the Co-5 wt.% Cr alloy. Corrosion rate measured could be correlated to the surface film composition and structure as determined by ESCA.     

A Modified Version of the Grimm's Glow Discharge Lamp for Use as a Demountable Hollow Cathode Emission Source. V. Determination of Minor Constitutents and Trace Elements in Steel

The applicability of the modified hollow cathode emission source to the determination of some elements usually contained in steel was tested in the case of chromium (0.144 – 3.07%), copper (0.090 – 0.49%), manganese (0.016 – 1.42%), molybdenum (0.007 – 1.41%), nickel (0.048 – 5.15%, silicon (0.013 – 0.81%), and vanadium (0.034 – 0.64%). The linearity of the calibration curves was found to be highly satisfactory, the Bravais - Pearson correlation coefficient ranging from 0.97 to 0.99. Moreover, results showed that background intensity is negligible and that blackening values can be plotted without resorting to internal standards or other preliminary corrections.     

石墨炉原子吸收光谱法测定化探样品中的微量钒

采用加入基体改进剂-石墨炉原子吸收光谱法测定化探样品中微量钒.研究了不同基体改进剂对钒测定结果的影响,确定了石墨炉原子吸收测定钒的最佳条件.结果表明,采用镧为基体改进剂,在5%的HC1介质中进行钒的测定可获得满意的结果.方法的检出限为2.11μg/L,线性范围0-300.0 μg/L,相关系数r=0.9959.该方法用...     

Local surrounding of vanadium atoms in CuCr1 − x V x S2: X-ray absorption spectroscopy analysis

In the present work local surrounding of vanadium atoms in layered copper-chromium disulfides CuCr_{1 ? x} V _x S₂ is investigated using high-resolution X-ray absorption spectroscopy above vanadium K-edge. Based on experimental and theoretically simulated spectra comparison it is shown that vanadium atoms replace chromium ones even at high concentrations of vanadium and that they are in 3+ oxidation state.     

利用低合金钢标样测定非镀锡薄板镀铬量

本文提出了以低合金钢标准样品代替无锡薄钢板参比样品 ,利用直读光谱仪测定无锡薄钢板镀铬量的方法。解决了国内外因没有无锡薄钢板标准样品而影响直读光谱法测定无锡薄钢板镀铬量方法的推广应用问题。本方法精度 RSD小于 2 .5% ,准确度为 150 mg/m2 ± 5mg/m2 。     

Material transport and degradation behavior of SOFC interconnects

The SOFC interconnect materials, both lanthanum chromite based oxides and Fe–Cr ferritic alloys, are discussed from the viewpoint of material transport which causes the degradation in conductivity or chemical stability. The controlling factors, such as effect of oxygen chemical potential gradient, interaction with other cell components, and surrounding gaseous atmospheres are evaluated. The role grain boundary is important in the transport of metal components in oxide materials such as lanthanum chromites, or oxide scales on alloy. The diffusivity of metal components in alloy is much faster, which causes the interdiffusion on nickel and chromium between alloy and anode current collector. The reaction of alloy and sealing materials would be more significant, since the chromium component in alloy easily reacts with alkaline earth components in sealing materials. The slight amount of water vapor in air may greatly enhance the chromium vaporization rate from chromium oxide (Cr₂O₃).     

V-5Cr-5Ti合金弹性和力学性质的第一性原理研究

V-5Cr-5Ti合金作为核聚变堆第一包层的主要候选结构材料之一,但对其力学性质的理论研究相对较少.采用随机固溶体模型,利用第一性原理方法计算出V-5Cr-5Ti合金的弹性常数、体模量、剪切模量、杨氏模量、泊松比和柯西压力等,并与计算出的纯钒的相关数值进行对比,结果表明V-5Cr-5Ti合金具有良好的塑性和强度,但其塑性要略低于纯钒的.并对加入氧原子后的V-5Cr-5Ti合金进行了相关计算,通过对比计算结果发现,由于氧原子的加入,使V-5Cr-5Ti合金的塑性和强度都出现了不同程度的降低.最后对V-5Cr-5Ti合金和纯钒的理论强度进行了计算,并绘制出两者的应力-应变关系图,通过对比再次验证了上面的结论.