一维链配位聚合物[Mn(acacen){N(CN)2}]n的合成、结构和性质的研究(英)

The manganese(Ⅲ) complex [Mn(acacen){N(CN)₂}]_n [H₂acacen=bis(acetylacetone)ethylenediimine] has been synthesized and the structure has been determined. The complex forms a one-dimensional chain structure via the bidentate bridge ligand μ_1,5-[N(CN)₂]^- linking [Mn(acacen)] moiety. The magnetic property of the compound (75～300 K) shows the existence of an antiferromagnetic exchange interaction among paramagnetic centers along the chain. CCDC: 244940.     

平面Gunn器件中的雪崩弛豫振荡

为了寻找一个高效率的固体振荡器,我们研究了Gunn二极管中的雪崩弛豫振荡。本文描述有源区比较短的平面Gunn器件,在数倍于阚值的强场下工作时出现的雪崩弛豫振荡,这种振荡现象归结于畴雪崩后的电子空穴对的周期性出现和消失。它的振幅可以比Gunn振荡大得多,而频率比Gunn振荡小几倍,并且受外电路参数影响很大,在负载匹配好的情况下,粗略地测得总效率可达36％。     

Synthesis and Crystal Structure of a Cadmium Coordination Polymer with Dicyanamide and 1,2-Bis（1,2,4-triazol- 1-yl）ethane

The new cadmium(II) coordination polymer [Cd(bte)2(dca)2]n 1 (bte = 1,2-bis(1,2,4- triazol-1-yl)ethane, dca = dicyanamide) was synthesized and characterized by single-crystal X-ray diffraction. The crystal is of monoclinic, space group P21/n with a = 8.7148(15), b = 8.6142(17), c = 15.204(3) A, β = 92.100(10)o, V = 1140.6(4) A3, Z = 2, Mr = 572.87, Dc = 1.668 g/cm3, F(000) = 572, μ = 1.004 mm-1, the final R = 0.0654 and wR = 0.1429 for 1737 observed reflections (I > 2σ(I)). The cadmium atom is coordinated equatorially by four nitrogen atoms from four bte ligands and axially by two nitrogen atoms from two dca anions to adopt a distorted octahedral geometry. Each bte molecule bridges two cadmium(II) atoms. Two strands of bte molecules are wrapped around each other, and held together by cadmium(II) atoms. 1 Forms a double chain structure containing eighteen-membered Cd2(bte)2 rings.     

单层镍锰层状双金属氢氧化物用于锂-氧电池双功能催化剂

将块体镍锰层状双金属氢氧化物(Ni_3Mn-LDHs)通过液相剥离法制备成单层Ni_3Mn-LDHs,然后采用自组装法获得Ni_3MnLDHs/CNT复合材料。采用X射线衍射(XRD)、扫描电镜(SEM)、透射电镜(TEM)对复合材料的结构进行分析,通过恒流充放电、循环伏安(CV)和电化学阻抗谱(EIS)研究电极的电化学过程。结果表明:Ni_3Mn-LDHs/CNT复合材料可以有效提升ORR和OER的催化活性,与CNT正极相比较,Ni_3Mn-LDHs/CNT正极在锂-氧电池中的放电容量提高了近300%,并且具有优异的倍率性能和循环稳定性。