Samarium Polyarsenides Derived from Nanoscale Arsenic

Zintl phases of arsenic and molecular compounds containing Zintl‐type polyarsenide ions are of fundamental interest in basic and applied sciences. Unfortunately, the most obvious and reactive arsenic source for the preparation of defined molecular polyarsenide compounds, yellow arsenic As₄, is very inconvenient to prepare and neither storable in pure form nor easy to handle. Herein, we present the synthesis and reactivity of elemental As⁰ nanoparticles (As⁰_Nano, d=7.2±1.8 nm), which were successfully utilized as a reactive arsenic source in reductive f‐element chemistry. Starting from [Cp*₂Sm] (Cp*=η⁵‐C₅Me₅), the samarium polyarsenide complexes [(Cp*₂Sm)₂(μ‐η²:η²‐As₂)] and [(Cp*₂Sm)₄As₈] were obtained from As⁰_nano, thereby generating the largest molecular polyarsenide of the f‐elements and circumventing the use of As₄ in preparative chemistry.     

电感耦合等离子体原子发射光谱(ICP-AES)法测定铅锭中11种杂质元素

研究了用酸分解试样后不需分离基体直接用电感耦合等离子体原子发射光谱(ICP-AES)法测定铅锭中银、铜、铋、砷、锑、锡、锌、铁、镉、镍、铊11种杂质元素的方法。优化了样品前处理条件及仪器检测条件。方法的检出限为0.0012～0.0168μg/mL,回收率为89%～110%,RSD为2.3%～5.0%。方法简便快速,检出限低,精密度和准确度能满足铅锭中杂质元素的检测要求,具有较强的实用性和可操作性,可用于铅锭中杂质元素的测定。     

Neutron texture investigations of hard magnetic Mn?Al bars

In the present work connection between magnetic properties and texture of two samples of the tetragonal MnAl phase are investigated. For texture studies classical angle dispersive neutron diffraction and neutron time-of-flight method have been applied. the process of specimen preparation is shortly described. The mathematical treatment of experimental data for complete texture analysis has been outlined. The texture of investigated samples is weak. Some main components in inverse pole figures are inclined with respect to the direction of easy magnetization. In this way the non-optimal magnetic properties of the investigated material can be explained.