Preparation, Characterization and Crystal Structure of [Be(NCSe)2(HCON(CH3)2)2]

 Di-N-selenocyanato-bis(N,N′-dimethylfor- mamide)beryllium (1) was prepared and characterized by chemical analyses, and single crystal X-ray structure analysis. Crystals of 1 are monoclinic with a = 1837.2 (8) pm, b = 547.1 (2) pm, c = 1435.6 (6) pm, β = 93.27 (4)°, space group C2/c, Z = 4. Beryllium is tetrahedrally coordinated by two N-bonded selenocyanate and two O-bonded N,N′-dimethylformamide ligands and intermolecular Se ⋯ Se as well as Se ⋯ H interactions are observed.     

中子反应总截面测量系统关联不确定度的模拟

在15 MeV电子加速器驱动的白光中子源装置上进行了铍材料的中子总反应截面测量,测量结果与已有实验数据和ENDF/VII.1数据库的评价数据基本符合。为了得到由于加速器束流波动、飞行路径测量、靶厚度测量以及获取系统死时间等引起的测量系统的关联不确定度,利用Geant4模拟软件对整个实验装置、实验过程进行了模拟,经过对模拟中使用的中子反应总截面与模拟计算得到截面的比较分析,得到了实验系统关联不确定度的估计值。在模拟中采用了局部区域增加权重的方法来降低模拟运算时间。对模拟得到的中子飞行时间谱与实验测量得到的飞行时间谱进行了比较,并且对探测器处的中子产额也进行了比较,以此来验证模拟程序的可靠性。     

Isolation of Cyclic(Alkyl)(Amino) Carbene–Bismuthinidene Mediated by a Beryllium(0) Complex

The long-sought carbene–bismuthinidene, (CAAC)Bi(Ph), has been synthesized. Notably, this represents both the first example of a carbene-stabilized subvalent bismuth complex and the extension of the carbene-pnictinidene concept to a non-toxic metallic element (Bi). The bonding has been investigated by single-crystal X-ray diffraction studies and DFT calculations. This report also highlights the hitherto unknown reducing and ligand transfer capability of a beryllium(0) complex.     

Recent Contributions to the Coordination Chemistry of Beryllium

Given the alleged extreme toxicity of beryllium and its compounds, it is the least investigated nonradioactive element. However, beryllium exhibits unique properties among the elements and therefore the related coordination chemistry is unprecedented. With the emergence of s-block catalysis and the introduction of low-valent magnesium complexes as versatile reducing agents, the interest in related beryllium compounds also has increased. Therefore, some quite remarkable progress on the coordination and organometallic chemistry of beryllium has been made in the last two decades. This Minireview article gives an oversight over the relatively recent developments in this field of beryllium research. An emphasis is placed on the correlation between the structure and reactivity of the described compounds.     

Compressions of ta10w alloy kennertium w-2, and beryllium oxide to 4.5 GPa

Abstract

The volume compressions of a tantalum alloy, tungsten alloy, and beryllium oxide (BeO) have been derived from the measurements of axial shortenings of cylindrical specimens of these materials to 4.5 GPa at room temperature. These measurements were carried out in a solid pressure medium piston- cylinder apparatus.     

铍原子1s22snp 3P态精细结构的理论计算

以多电子原子精细结构哈密顿的球张量形式为基础,借助不可约张量理论,对铍原子1s22snp(n=2-6) 3P态精细结构(包括自旋-轨道相互作用、自旋-其它轨道相互作用和自旋-自旋相互作用)进行了具体地计算,并将计算结果与文献结果进行了比较,符合地较好。同时,计算了1s22snp(n=2-6) 3P态精细结构参数A和B的值。     

铍原子1s22snp3P态精细结构的理论计算

以多电子原子精细结构哈密顿的球张量形式为基础,借助不可约张量理论,对铍原子1s22snp(n=2～6) 3p态精细结构(包括自旋-轨道相互作用、自旋-其它轨道相互作用和自旋-自旋相互作用)进行了具体地计算,并将计算结果与文献结果进行了比较,符合地较好.同时,计算了1s22snp(n=2～6)3p态精细结构参数A和B的值.     

Use of 1-Hydroxy-2-Carboxyanthraquinone for the Spectrofluorometric Determination of Be(II)

Abstract

A new spectrofluorometric method for the determination of beryllium using 1-hydroxy-2-carboxyanthraquinone as the reagent is described. A study of the interference by foreign ions was also completed.     

Pair potential of liquid metallic Be from electron theory compared and contrasted with recent ab initio work on the free-space beryllium dimer

Two decades ago, Perrot and March [F. Perrot and N.H. March, Phys. Rev. A. 41, 4521 (1990)] used electron theory to derive an oscillatory pair potential between the beryllium nuclei in liquid metal beryllium. They predict a first minimum at 2.1?Å, followed by a larger repulsive hump at 2.8?Å. Here, we compare and contrast this result for liquid beryllium with the recent ab initio work by Koput and the present quantum Monte Carlo (QMC) calculation on the beryllium dimer in free space. Koput situates the minimum in the potential curve for the free-space dimer at 2.4?Å and it is quite similar in depth to that for liquid metallic beryllium. Our QMC curve is similar, with the minimum at 2.33?Å. They are tabulated in this letter.