N-Doped Graphdiyne Coating for Dendrite-Free Lithium Metal Batteries

Nonuniform nucleation is one of the major reasons for the dendric growth of metallic lithium, which leads to intractable problems in the efficiency, reversibility, and safety in Li-based batteries. To improve the deposition of metallic Li on Cu substrates, herein, a freestanding current collector (NGDY@CuNW) is formed by coating pyridinic nitrogen-doped graphdiyne (NGDY) nanofilms on 3D Cu nanowires (CuNWs). Theoretical predictions reveal that the introduction of nitrogen atoms in the 2D GDY can enhance the binding energy between the Li atom and GDY, therefore improving the lithiophilicity on the surface for uniform lithium nucleation and deposition. Accordingly, the deposited metallic Li on the NGDY@CuNW electrode exhibits a dendrite-free morphology, resulting in significant improvements in terms of the reversibility with a high coulombic efficiency (CE) and a long lifespan at high current density. Our research provides an efficient method to control the surface property of Cu, which also will be instructive for other metal batteries.     

Highly efficient AgNO3‐catalyzed approach to 2‐(benzo[d]azol‐2‐yl)phenols from salicylaldehydes with 2‐aminothiophenol, 2‐aminophenol and benzene‐1,2‐diamine

A new, convenient and efficient AgNO₃‐catalyzed strategy for the preparation of 2‐(benzo[d]azol‐2‐yl)phenol derivatives in good to excellent yields (63–98%) is described. The reaction proceeds via condensation/intramolecular nucleophilic addition/oxidation process between substituted salicylaldehydes and 2‐aminothiophenol, 2‐aminophenol or benzene‐1,2‐diamine under mild reaction conditions. Notably, this reaction utilizes cheap AgNO₃ as a readily available and low‐cost benign oxidant at low catalyst loadings with excellent functional group tolerance.     

Vector sampling expansions in shift invariant subspaces

Multi-input multi-output (MIMO) sampling scheme which is motivated by applications in multi-channel deconvolution and multi-source separation has been investigated in many aspects. Common for most of results on MIMO systems is that the input signals are supposed to be band-limited. In this paper, we study vector sampling expansions on general finitely generated shift-invariant subspaces. Necessary and sufficient conditions for a vector sampling theorem to hold are given. We also give several examples to illustrate the main result.     

液体光击穿阈值的研究

运用声学基础理论,讨论了激光入射到液体中,激光能量与声信号强度间的变化关系.发现激光能量与声信号强度之间存在着对数线形关系.根据液体中光声信号的连续性,得到了一种求取液体光击穿阈值的新方法.     

The nonlinear optical response of a fluorine-containing azoic dye

The nonlinear optical nonlinearities of a fluorine-containing azoic dye in tetrahydrofuran have been investigated by using Z-scan technique with picosecond and nanosecond lasers. The experimental results reveal that the azoic dye has large optical nonlinearity under the excitations of picosecond and nanosecond 532 nm. At the picosecond 532 nm the solution presents negative nonlinear refraction due to the electronic effect, while the larger nonlinear refraction under nanosecond laser excitation is induced by thermal effect. Moreover, the different nonlinear absorption behavior under picosecond and nanosecond excitations is analyzed.     

Bursting oscillations, bifurcation and synchronization in neuronal systems

This paper investigates bursting oscillations and related bifurcation in the modified Morris-Lecar neuron. It is shown that for some appropriate parameters, the modified Morris-Lecar neuron can exhibit two types of fast-slow bursters, that is “circle/fold cycle” bursting and “subHopf/homoclinic” bursting with class 1 and class 2 neural excitability, which have different neuro-computational properties. By means of the analysis of fast-slow dynamics and phase plane, we explore bifurcation mechanisms associated with the two types of bursters. Furthermore, the properties of some crucial bifurcation points, which can determine the type of the burster, are studied by the stability and bifurcation theory. In addition, we investigate the influence of the coupling strength on synchronization transition and the neural excitability in two electrically coupled bursters with the same bursting type. More interestingly, the multi-time-scale synchronization transition phenomenon is found as the coupling strength varies.     

射频驱动下电磁诱导透明窗口的分裂和增益的出现

在Λ型三能级系统的基础上引入两个共振射频场, 通过详细讨论系统的探测吸收特性随两个射频场Rabi频率取不同值时的变化规律, 得出电磁诱导透明(EIT)的分裂规律以及EIT上出现增益现象的产生条件.研究结果表明: 两个射频场对系统所起的控制作用不同, 控制基态精细结构能级之间跃迁的射频场对EIT的分裂起作用, 而控制激发态精细结构能级之间跃迁的射频场不会导致EIT的分裂; 而且, 只有当控制基态精细结构能级之间跃迁的射频场的Rabi频率大于控制激发态精细结构能级之间跃迁的射频场的Rabi频率时, 才能产生EIT与增益相叠加的新特性. 关键词： 射频场 电磁诱导透明 增益 精细结构能级     

Traveling waves in a generalized nonlinear dispersive–dissipative equation

D. Zeidan In this paper, we consider the existence of traveling waves in a generalized nonlinear dispersive–dissipative equation, which is found in many areas of application including waves in a thermoconvective liquid layer and nonlinear electromagnetic waves. By using the theory of dynamical systems, specifically based on geometric singular perturbation theory and invariant manifold theory, Fredholm theory, and the linear chain trick, we construct a locally invariant manifold for the associated traveling wave equation and use this invariant manifold to obtain the traveling waves for the nonlinear dispersive–dissipative equation. Copyright © 2015 John Wiley & Sons, Ltd.     

微生物胞外聚合物对重金属镉的解毒作用及红外光谱分析

为探索微生物胞外物在微生物对重金属的抗性和去除过程中的作用,比较分析了对重金属镉具有不同抗性和去除率的菌株SCSE425-7和SCSE709-6胞外物的产生情况和菌株的红外光谱谱图。结果表明,在含镉条件培养时,菌株SCSE425-7表现了较高的镉抗性,分泌了相对较多的可溶性胞外多糖;而菌株SCSE709-6镉抗性较SCSE425-7低,但镉的生物去除性能较好,分泌了更多不可溶胞外聚合物。这说明,在重金属毒性胁迫下,微生物分泌的可溶性胞外多糖可能有助于提高微生物对重金属的抗性,而不可溶性胞外聚合物有助于重金属的微生物吸附。菌株红外光谱分析结果表明不可溶胞外聚合物上的酰胺基和羧基是其吸附镉离子的主要官能团。