石墨炉原子吸收光谱法测定钢中痕量锡

锡通常是作为有害杂质存在于钢中,一部分锡形成固溶体存在于碳化铁中。锡可以增加钢的抗拉强度却降低了钢的冲击值和冲击性能,不利于钢的加工。一般应严格控制其含量。因此,准确测定钢铁中痕量锡的含量很重要。目前,测定锡的方法有苯基荧光酮十六烷基三甲基溴化铵(CTMAB)直接光度法、原子荧光光谱法和石墨炉原子吸收光     

石墨炉原子吸收法测定铬钢中微量锡

钢中锡为有害元素,会引起钢的性质变差,降低铬铝钒钢的持久强度.其量每增加0.01%,断裂时间缩短10%.原因是锡易在晶界上偏析,造成回火时钢材脆化.所以对钢中锡的测定结果是否正确是至关重要的.微量锡的测定,通常应用化学法、氢化发生-原子吸收法、ICP-MAS法等.化学湿法操作繁琐,试剂耗用多,试剂空白不易掌握;ICP-MAS法仪器昂贵,难以普及.石墨炉原子吸收法作为多种金属元素测定最灵敏技术,为国际标准化组织(ISO)推荐用于碳钢中微量锡的测定.文献[1]报道在测定时,可加入如硝酸镍、硝酸镁、硝酸铰、抗坏血酸和镉等基体改进剂.本文则在前人的基础上,建立了以抗坏血酸作基体改进剂的石墨炉原子吸收法测定铬钢中微量锡,方法简便快速、准确可靠.     

碱性氢化物发生—火焰原子吸收光谱法测定锡

对Ｓｎ－ＮａＯＨ－ＫＢＨ４体系进行了系统研究，采用三乙醇胺－ＥＤＴＡ联合干扰抑制剂，可消除一定量铁及合金元素的干扰，对于锡含量小于０．０１％的试样，用苯萃取锡后所有元素不干扰测定。测定液中锡量为０－４μｇ／１０ｍｌ，呈线性关系，灵敏度为０．００４ｍｇ／Ｌ／１％，检出限为０．００８ｍｇ／Ｌ，测定钢中大于０．００１％锡，结果满意。     

镧对含锡、锑残余元素的34CrNi3Mo钢热塑性的改善作用

采用Gleeble-1500热模拟机测定了不同含量的残余元素锡、锑及稀土镧对低氧、低硫的34CrNi3Mo钢热塑性的影响;采用SEM及EDS手段研究了稀土镧对不同锡、锑含量的钢断裂方式的影响及在其中形成夹杂物的情况。结果表明,用稀土金属可以改善低氧、低硫钢中残余元素对钢性能的危害;镧可以和钢中较低含量的锑作用生成镧锑金属间化合物,并且发现了少量的镧锡金属间化合物。     

氢化物发生-原子荧光光谱法测定核电用钢中痕量锡

提出了氢化物发生-原子荧光光谱法测定核电用钢中痕量锡的方法。样品在酒石酸溶液存在下,用盐酸-硝酸(3+1)混合酸溶解,用50 g·L-1硫脲-抗坏血酸混合溶液作掩蔽剂,20 g·L-1硼氢化钾溶液作为锡(Ⅳ)的还原剂,氢化反应在pH 5.0~5.5介质中进行,锡的质量浓度在50μg·L-1范围以内与相应的荧光强度呈线性关系,方法的检出限(3s/k)为0.4μg·L-1。应用此方法分析了核电用钢及不锈钢标准样品中锡的含量,并与电感耦合等离子体原子发射光谱法作了比较,测定值与标准值相符,结果的相对标准偏差(n=8)均小于4.5%。     

含锡易切削钢的初步研究

以金属锡和锡矿粉替代铅,研制了一种新型含锡的易切削钢,并进行了切削和力性测试.结果表明,在一定含量范围内,锡能明显改善钢的易切削性能,对力学性能无不利影响.用扫描电镜和能谱对钢中的夹杂物和断口进行了观察和鉴定,表明在晶界及夹杂物附近锡有较大程度的偏聚.     

槲皮素光度法测定铝锡合金中的锡

槲皮素光度法测定铝锡合金中的锡吴光进，李家华，赵红梅，洪珊（贵州省理化测试分析研究中心贵阳市５５０００２）槲皮素光度法已用于铜合金中锡量的测定￣［１］，但由于干扰元素较多，尚未见报道用于其它合金中锡量的测定。为此、本文就槲皮素光度法测定铝锡合金中锡量...     

电感耦合等离子体原子发射光谱法测定钛铁中锰、磷、铜、硅、铝、钒和锡

钛铁作为炼钢合金元素的添加剂和除气材料加入钢中,钛在钢中除了以固溶体的形态存在外,还作为一种高级合金,和氮、氧、碳形成化合物氮化钛、二氧化钛、碳化钛,从而防止钢中产生气泡并改善钢的品质,提高钢的机械强度,是冶炼高质量不锈钢不可替代的原料之一,因此被广泛地应用于低合金钢、高强度钢中[1]。准确地分析出钛铁中锰、磷、铜、硅、铝、钒和锡的含量,对于炼钢的成分控制有着十分重要的意义。国家标准分析方法测定钛铁中锰、磷、铜、硅、铝、钒     

三苯基锡与邻氨基苯甲酸型Schiff碱配合物的合成及表征

合成了两种新的三苯基锡与邻氨基苯甲酸型Ｓｃｈｉｆｆ碱的配合物，经元素分析，ＵＶ，ＩＲ，ＨＮＭＲ测定，其结果进行了表征。结果表明，两种配合物具有不同的结构。在三苯基锡与水杨醛缩邻氨基苯甲酸Ｓｃｈｉｆｆ碱的配合物中，锡原子六配位的，存在着酚羟基氧和亚氨基氮与锡配键。在三苯基锡与２－羟基－１－萘醛缩邻氨基苯甲酸Ｓｃｈｉｆｆ碱的配合物中，锡原子是五配位的，酚羟基氧和亚氨基氮均未与锡配闰，但存在羰基氧与锡配     

气体分析用锡片和锡囊的研制与应用

本文提出了一种填补国内空白的新产品－气体分析用锡片和锡囊的研制方法。对锡片，锡囊的外观和内在质量检测结果证明，研制的锡片，锡囊完全达到了美国ＬＥＣＯ公司同类产吕的技术标准，而价格只有进口产品的四分之一左右。应用结果表明，该产品完全可以取代进口，完全适用于用事种金属及其俣金材料中气体分析的要求。     

利用手持技术改进测定乙醇分子结构实验

利用压强传感器代替排水集气法,改进测定乙醇分子结构实验的仪器装置,并探索最佳反应条件。另外,设计两个空白实验,结合压强变化曲线对实验误差进行相关讨论。     

Neutral diterpenoids of oleoresins of five species of conifers of Transcarpathia

The compositions of the neutral diterpenoids of the oleoresins of five species of conifers growing in the Transcarpathia have been studied. It has been found that the oleoresins ofAbies alba M.,Larix decidua M., andPicea excelsa L. contain more than 50% of neutral diterpenoids. The group and qualitative compositions of the oxygen-containing diterpenoids have been determined. In the oleoresins ofAbies alba,Picea excelsa, andPicea abies tertiary alcohols — cis-abienol and isocembrol — predominate, while inLarix decidua the main component is the hydroxy ester larixyl acetate. Primary alcohols related to the resin acids have been found in all the oleoresins investigated. Features of the distribution of diterpenoids according to the species of conifers have been revealed. The results obtained are necessary for the chemotaxonomy of conifers of the family Pinceae.Novosibirsk Institute of Organic Chemistry, Siberian Branch, Academy of Sciences of the USSR. Translated from Khimiya Prirodynkh Soedinenii, No. 6, pp. 812–816, November–December, 1988.     

光谱仪测试范围的扩展

由于石化行业的生产需要，其材质的使用具有多样性和广泛性，经常会出现顾客委托的测试样品的一个或几个元素跨越光谱仪现有测试程序测量范围的情况。本法通过对光谱仪测试原理的认识，根据光谱仪的测试能力及标样的采集，实现了一个或几个元素测量范围的扩展，并对其测量的影响因素进行了研究。     

Influence of viscosity of medium on processes of oxygen quenching of excited states of mesoporphyrin

The oxygen quenching rate constants for singlet and triplet excited states of the dimethyl ester of mesoporphyrin IX increase with decreasing viscosity of the medium and reach a maximum at a viscosity of approximately 0.4 mPa·sec, after which the rate constants begin to decrease. The drop in rate constant with increasing fluidity of the medium may be related to a nonequilibrium character of the elementary act in the interaction of the reactants in the solvent cage. In viscous media such as isopropyl alcohol, isobutyl alcohol, and isoamyl alcohol, the reaction radius is greater than the sum of the radii of the reacting particles. The long-range character of these processes is due to the relatively weak dependence of the quenching probability on distance.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 25, No. 2, pp. 161–167, March–April, 1989.     

Dichroism of absorption and polarization of phosphorescence of molecules of the closed form of nitrobenzospirothiopyran

The spectral-polarization characteristics of absorption and phosphorescence of molecules of the initial form of nitro-substituted indolinospirobenzothiopyran were studied in oriented polyethylene films and in solutions with different polarity. An oscillator model of the electron transitions responsible for the formation of absorption and luminescence spectra was suggested. It was established that the principal differences in the spectral and photophysical properties of the compound studied and its oxygen-containing analog are associated with the fact that the electronegativity of the S atom is lower than that of the O atom. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1143–1146, June, 1997.     

Determination of heats of detonation and influence of components of composite explosives on heats of detonation of high explosives

The heats of detonation of 20 simple high explosives and explosive mixtures were determined by means of an adiabatic detonation calorimeter designed by the authors. The results indicated that the performance of the instrument was reliable and the experimental data were very accurate. For explosive mixtures, there was a linear accumulative relationship between the heats of detonation of the explosive mixture and its components. Accordingly, the heats of detonation of explosive mixtures could be calculated directly from the heats of detonation of simple explosives and the characteristic heats of other components. The experiments showed that the gold or brass shell of the cylindrical charge could be substituted by a thick-walled porcelain shell, which had the advantage of cheapness.

     

物质分配系数的测定实验改进

实验教学目的是从解决实际问题出发,以实验技术训练和实验设计思想培养为目标。介绍了将单一的物质分配系数测定实验改进为综合实验,提高了实验效果及实验资源利用率。     

Calculation of enthalpies of hydrogenation of hydrocarbons

Sets of hydrogen molecule equivalents have been developed which permit the calculation of hydrogenation of different types of carbon-carbon bonds from ab initio total energies (3-21G and 6-31G* basis sets, and, to a more limited extent, for MP2/6-31G* data) of reactants and products. The calculated enthalpies of hydrogenation are in good agreement with experiment for unstrained molecules, with average errors on the order of 2 kcal/mol. The 6-31G* equivalents allow the enthalpies for strained molecules to be calculated accurately, but the 3-21G equivalents do not. The equivalents for both basis sets have been tested by calculating the enthalpies of hydrogenation of carbon-carbon bonds in nitrogen- and oxygen-containing organic molecules, free radicals, and classical carbocations. The results are in good agreement with experiment in most cases.     

非那雄胺合成工艺改进

非那雄胺能抑制5α-还原酶的活性,明显降低二氢睾酮水平,是一种治疗良性前列腺增生的有效药品。该合成工艺以甾烯酮酸为原料,将其与氯化亚砜反应,无须分离即与叔丁胺反应得17β-酰胺化合物,再氧化开环,环合,氢化,脱氢合成了非那雄胺。经元素分析、IR、1HNMR、13CNMR、MS分析表征了其结构。该法无须使用昂贵的2,2-二吡啶二硫化物和剧毒药品苯亚硒酸酐,且以乙酸铵代替氨气,降低了对设备的要求和腐蚀,更适用于工业生产。