Engineered nitrogen doping on VO_(2)(B)enables fast and reversible zinc-ion storage capability for aqueous zinc-ion batteries

Vanadium-based compounds with high theoretical capacities and relatively stable crystal structures are potential cathodes for aqueous zinc-ion batteries(AZIBs).Nevertheless,their low electronic conductivity and sluggish zinc-ion diffusion kinetics in the crystal lattice are greatly obstructing their practical application.Herein,a general and simple nitrogen doping strategy is proposed to construct nitrogen-doped VO_(2)(B)nanobelts(denoted as VO_(2)-N)by the ammonia heat treatment.Compared with pure VO_(2)(B),VO_(2)-N shows an expanded lattice,reduced grain size,and disordered structure,which facilitates ion transport,provides additional ion storage sites,and improves structural durability,thus presenting much-enhanced zinc-ion storage performance.Density functional theory calculations demonstrate that nitrogen doping in VO_(2)(B)improves its electronic properties and reduces the zinc-ion diffusion barrier.The optimal VO_(2)-N400 electrode exhibits a high specific capacity of 373.7 mA h g^(-1)after 100 cycles at 0.1 A g^(-1)and stable cycling performance after 2000 cycles at 5 A g^(-1).The zinc-ion storage mechanism of VO_(2)-N is identified as a typical intercalation/de-intercalation process.

In-plane uniaxial-strain tuning of superconductivity and charge-density wave in CsV_(3)Sb_(5)

The kagome superconductor CsV_(3)Sb_(5) with exotic electronic properties has attracted substantial research interest,and the interplay between the superconductivity and the charge-density wave is crucial for understanding its unusual electronic ground state.In this work,we performed resistivity and AC magnetic susceptibility measurements on CsV_(3)Sb_(5) single crystals uniaxially-strained along[100]and[110]directions.We find that the uniaxial-strain tuning effect of T_(c)(dT_(c)/dε)and T_(CDW)(dT_(CDW)/dε)are almost identical along these distinct high-symmetry directions.These findings suggest the in-plane uniaxial-strain-tuning of T_(c) and T_(CDW)in CsV_(3)Sb_(5) are dominated by associated c-axis strain,whereas the response to purely in-plane strains is likely small.

可见光诱导下四丁基三溴化铵催化的苄位碳氢键氧化反应

芳烃苄位碳氢键的直接氧化官能团化可以实现羰基化合物的快速合成,在有机合成中具有重要意义.光照条件下,利用相对绿色、易得的氧气作为氧化剂实现这一反应,在过去十几年中获得了快速的发展.将一种市售、廉价的化学试剂四丁基三溴化铵用于催化苄位碳氢键的光氧化反应.在可见光照射下,以空气作为氧化剂,使用催化量的四丁基三溴化铵,即可完成烷基芳烃至芳基酮的有效转化.该反应条件温和,不需使用添加剂,底物适用范围广,可作为目前苄位光氧化反应体系的有效补充.

DTDE:A new cooperative multi-agent reinforcement learning framework

A significant body of work on reinforcement learning has been focused on the single-agent tasks where the agent aims to learn a policy thatmaximizes the cumulative reward in a dynamic environment.1 In the past decades,quite a few single-agent-based reinforcement learning algorithms have been developed in the literature.1 Yet,it is increasingly recognized that the single-agentbased reinforcement learning algorithms may fail to effectively handle largescale optimization(decision)tasks with joint features.

Superconductivity and spin fluctuations

在常规超导体，库柏对被声子调停，它是在声子和电子的电荷性质之间的关联仅仅被需要的一个过程。然而，超导性能也从基本刺激的另外的类型被导出。旋转变化可以证明是能调停的最有希望的候选人如此的异乎寻常的超导性。在一些象 cuprates，基于 Fe 的超导体和重费米子的超导体那样的重要系统，尽管仍然有许多争论，旋转变化在他们的超导性的机制起一个关键作用。在这份报纸，我们将在在旋转变化和超导性之间的关联上给简短评论。

Constructing ultrastable electrode/electrolyte interface for rapid potassium ion storage capability via salt chemistry and interfacial engineering

Conversion/alloying anode materials exhibiting high K storage capacities suffer from large volume variations and unstable electrode/electrolyte interfaces upon cycling.Herein,taking SnS/reduced graphene oxide(SnS/rGO)anodes as an example,the electrochemical performance of SnS/rGO could significantly be improved via employing potassium bis(fluorosulfonyl)imide(KFSI)salt in electrolytes and ultrathin TiO_(2) coating.KF-rich inorganic layer was demonstrated to help form robust SEI layer,which could suppress the side reactions to increase the Coulombic efficiency.The formed potassiated K_(x)TiO_(2) coating layer was constructed to boost charge transfer capability and K-ion diffusion kinetics.The as-prepared SnS/rGO@TiO_(2)-20 electrode in KFSI electrolyte delivers the high CE of 99.1%and 424 mAh·g^(−1) after 200 cycles with an ultrahigh capacity retention of 98.5%.

Continuous synthesis for zirconium metal-organic frameworks with high quality and productivity via microdroplet flow reaction

Zirconium metal-organic frameworks（Zr-MOFs） represent the most promising candidates among MOFs for industrial utilizations owing to their high porosity and excellent stability. However, the efficient synthesis of Zr-MOFs combining with continuous production, high productivity and good product quality still remains a critical issue for practical applications. Herein, we report an efficient method of synthesizing a series of Zr-MOFs through a microdroplet flow reaction, which is more accommodate the requirements of industrial production. Four types of Zr-based MOFs with different ligands and topologies（MOF-801, MOF-804, DUT-67 and MOF-808） were produced as a pure phase of high quality crystalline with uniform morphologies. Furthermore, this series of Zr-MOFs were obtained in a continuous way and at a space-time yield（STY） highly up to 367.2 kg m-3 d-1. These MOFs exhibit the similar pore structure and thermal stability with that prepared from conventional solvothermal synthesis. CO2 sorption studies on these MOFs demonstrate that the hydroxyl groups on ligand can render MOFs with high CO2/N2 selectivity.