Hydrothermal synthesis, structure and quantum chemistry of transition metal complex supported by metal-oxo cluster [(Ni(phen)22 (ξ-Mo8O26)]

A nickel-1,10-phenanthroline complex supported on an octamolybdate, [(Ni(phen)_{2 2}(ξ-Mo₈O₂₆)], has been hydrothermally synthesized with MoO₃, H₂MoO₄, Ni(OAc)₂ 6H₃O and 1,10-phenathroline (1,10-phen) as raw materials. The crystals of the compound belong to monoclinic P2₁/n space group,a = 1.2952(2),b = 1.6659(10),c = 1.3956(12) nm, β =106.273(8)°,V = 2.8906(5) nm³,Z = 2. 5604 observable reflections (I >2σ(I)) were used for structure resolution and refinements to converge to finalR ₁ = 0.0414,wR ₂ = 0.0815. The result of structure determination shows that the compound contains octamolybdate possessing a novel structure type (named as ξ-isomer). The feature of ξ-[Mo₈O₂₆]^4- is that it is composed of Mo₆O₆ ring and two MoO₆ octahedral located at cap positions on opposite faces. The Mo₆O₆ ring contains two octahedral and four trigonal-bipyramidal Mo^VI atoms. Each ξ-[Mo₈O₂₆]^4- unit is bonded with two [Ni(phen)₂]²⁺ through terminal oxygen atoms of octahedral and neighbouring trigonal-bipyramidal Mo atom in the Mo₆O₆ ring. IR and UV-Vis spectra of the compound were measured and its electronic structure was studied by EHMO method.     

Synthesis of CuS@CoS2 Double‐Shelled Nanoboxes with Enhanced Sodium Storage Properties

Metal sulfides have received considerable attention for efficient sodium storage owing to their high capacity and decent redox reversibility. However, the poor rate capability and fast capacity decay greatly hinder their practical application in sodium‐ion batteries. Herein, an elegant multi‐step templating strategy has been developed to rationally synthesize hierarchical double‐shelled nanoboxes with the CoS₂ nanosheet‐constructed outer shell supported on the CuS inner shell. Their structure and composition enable these hierarchical CuS@CoS₂ nanoboxes to show boosted electrochemical properties with high capacity, outstanding rate capability, and long cycle life.     

Bi‐Microporous Metal–Organic Frameworks with Cubane [M4(OH)4] (M=Ni,Co) Clusters and Pore‐Space Partition for Electrocatalytic Methanol Oxidation Reaction

Embedding cubane [M₄(OH)₄] (M=Ni, Co) clusters within the matrix of metal–organic frameworks (MOFs) is a strategy to develop materials with unprecedented synergistic properties. Herein, a new material type based on the pore‐space partition of the cubic primitive minimal‐surface net (MOF‐14‐type) has been realized. CTGU‐15 made from the [Ni₄(OH)₄] cluster not only has very high BET surface area (3537 m² g^?1), but also exhibits bi‐microporous features with well‐defined micropores at 0.86 nm and 1.51 nm. Furthermore, CTGU‐15 is stable even under high pH (0.1 m KOH), making it well suited for methanol oxidation in basic medium. The optimal hybrid catalyst KB&CTGU‐15 (1:2) made from ketjen black (KB) and CTGU‐15 exhibits an outstanding performance with a high mass specific peak current of 527 mA mg^?1 and excellent peak current density (29.8 mA cm^?2) at low potential (0.6 V). The isostructural cobalt structure (CTGU‐16) has also been synthesized, further expanding the application potential of this material type.     

冠状病毒抑制剂的研究进展

冠状病毒是一类广泛存在且对人及家畜具有严重危害的病原体,其中于2003年全球爆发的严重急性呼吸综合征病毒(SARS-CoV)以及2012年被发现并传播的中东呼吸综合征病毒(MERS-CoV)给人们的生命健康以及全球经济造成了严重威胁以及重大损失,特别是2019年末爆发的新型冠状病毒(SARS-CoV-2),截至目前为止已经造成了几百万的感染病例以及几十万人的死亡。可以看出,冠状病毒具有较高的传播性以及较高的致死率,时刻威胁着人们的健康安全,但是针对冠状病毒的感染目前还没有批准上市的有效药物,也没有用于预防的疫苗。本文围绕目前关于冠状病毒的潜在成药性靶点,详细介绍了针对这些靶点的具有代表性的抑制剂的结构设计及其化学合成方法,以期为目前抗冠状病毒药物的研发提供一些参考。     

基于透明质酸构筑的药物递送载体及其应用

传统纳米药物控释载体主要通过细胞胞吞作用实现药物递送,其主要过程为被动靶向机制,因此会影响纳米载体在肿瘤组织的富集和治疗效果.近年来生物大分子透明质酸因其优异的水溶性、生物相容性、可降解性和肿瘤靶向性备受科研工作者青睐,已被广泛用于药物控释载体的构筑中,并成为靶向肿瘤治疗纳米载体领域的研究热点.本文根据透明质酸基纳米载...     

波分系统光层面保护技术的应用研究

本文首先分析了光层面的保护技术,并对目前比较成熟的光线路保护（OLP）、光通道保护（OCP）技术进行了探讨,接着本文从实际工程应用的角度,探讨了光层保护技术的实际应用以及一些需要注意的问题,最后对光层保护的发展方向做了展望。     

电信级以太网关键技术分析

文章在简单介绍了城域网的发展趋势后,从扩展性、QoS、安全、可靠性、管理5个角度,详细分析了目前几种主流电信级以太网技术在具体实现上的异同,同时针对性地介绍了几个解决问题的关键方法.     

Effect of exit and injection rates on phase-dependent transient evolution of gain without inversion

It is shown that in an open Λ-type system with spontaneously generated coherence, the transient evolution rule of the gain of lasing without inversion (LWI) is very sensitive to variation of the relative phase φ between the probe and driving fields; the variety of the atomic exit rateγ_0 and the ratio C of the atomic injection rates also have a considerable effect on the phase-dependent transient evolution rule of LWI gain. We find that whenφ=0, the transient and stationary LWI gain increases with C increasing but decreases with γ_0 increasing; whenφ≠0 , the effect of C andγ_0 on LWI gain is just opposite to that when φ=0 ; in order to get the largest transient and stationary LWI gain, we need selecting suitable values of φ,γ_0 and C.     

3D optical vortices generated by micro-optical elements and its novel applications

In this paper we report on recent development in the areas of optical vortices generated by micro-optical elements and applications of optical vortices, including optical manipulation, radial polarization and secure free space optical communi- cation     

Efficient One-Step Synthesis of N,N′-Bis(2-Hydroxy-5-Bromobenzylidene) Arylmethamediamines

The tittle compounds have directly been synthesized by one-step reaction of two different aldehydes in the presence of ammonia in good to excellent yields.