Scalable 3D Self-Assembly of MXene Films for Flexible Sandwich and Microsized Supercapacitors

The self-assembly of large-area MXene films is the main step to realize their applications in various energy storage devices. However, the scalable self-assembly of flexible thin MXene films with high conductivity as well as excellent mechanical and electrochemical properties is still a challenge. Herein, a synchronous reduction and self-assembly strategy to fabricate flexible MXene films is developed, where MXene films are synchronously reduced and self-assembled on the Zn foil surface. Furthermore, the self-assembly of MXene films can be scaled up by controlling the area of Zn substrates. By adjusting the patterns of Zn substrates, the interdigital MXene patterns can also be obtained via a selectively reducing/assembling process. The resultant MXene films demonstrate high electrical conductivity, large specific surface area, and excellent mechanical properties. Thus they can serve as the electrodes of flexible supercapacitor devices directly. As a proof of concept, flexible sandwich and microsized supercapacitors are designed based on the above MXene film electrodes. Both sandwich and microsized supercapacitors display stable electrochemical performance under various bending states. This study provides a route to achieve large-area MXene-based films or microsized structures for applications in the field of energy storage.     

DVB-S2中LDPC编解码分析

本文在简要介绍LDPC码的基础上，就DVB—S2标准中LDPC编解码过程进行了详细的分析，指出了值得关注和研究的元素。     

关于提高变频器调频速度的研究

本文介绍了作者的一项专利技术。对于需要比较快速、比较频繁地调整变频器频率应用场合,目前的通用变频器就很难满足这个需要,尤其是在大惯性负载上使用变频器时,须将升、降频（特别是降频）速度设置的比较慢,以适应由于惯性造成的电机转速的滞后。本专利技术克服上述传统变频器目前存在的缺陷,在传统变频器上增加比较简单并业已成熟的换相技术,为变频器的制造提供了一种新的附加技术。     

Al_xGa_(1-x)As_ySb_(1-y)/GaSb的LPE生长与性质研究

在GaSb衬底上用LPE法生长了晶格匹配的AlGaAsSb外延层。用室温光致发光和X射线双晶衍射分别测量了材料的禁带宽度和晶格常数,并与用内插法计算的结果进行了比较。用C-V和van der Pauw法测量了样品的电学参数。用激光喇曼散射和低温光致发光研究了材料的光学性质,观察到了类GaSb的LO模和类AlSb的LO模以及LO声子与等离子激元的耦合模L_-;对x=0.2,y=0.025的样品,由低温到室温的变温光致发光测量确定的禁带宽度的温度系数为-3.2×10~(-4)eV/K。此外对于晶格失配,P型的原因以及PL谱峰的展宽等问题进行了讨论。     

复合材料结构用高锁螺栓的动态复合加载失效特性

为研究复合材料结构用高锁螺栓的动态复合加载失效特性,基于高速液压伺服材料实验机设计专用的实验支持装置,提出碰撞式实验加载方法。实现中国商用飞机有限责任公司紧固件工艺标准CFBL1001-6-6/CFNT1003CY6抗剪型高锁螺栓在0.01 m/s、0.10 m/s、1.00 m/s加载速度及纯拉伸、30°拉伸-剪切耦合、45°拉伸-剪切耦合、60°拉伸-剪切耦合、纯剪切状态下的失效测试,并基于实验结果拟合得到高锁螺栓的失效参数。结果表明：提出的测试方法能够有效获取高锁螺栓的动态失效参数;CFBL1001-6-6/CFNT1003CY6高锁螺栓的失效模式和失效载荷受加载方式影响较大,受加载速度影响较小;拟合获得的失效方程可较好地表征高锁螺栓的失效特性。     

Tailoring Anion Association Strength Through Polycation-Anion Coordination Mechanism in Imidazole Polymeric Ionic Liquid-Based Artificial Interphase toward Durable Zn Metal Anodes

Artificial interface layer engineering is an efficacious modification strategy for protecting zinc anode from dendrite growth and byproducts formation. However, the high bulk ionic conductivity of most artificial interfacial layers is mainly contributed by the movement of anions (SO₄²⁻), which is the source of parasitic reactions on zinc anode. Herein, a high zinc ion donor transition (σZn²⁺ = 3.89 × 10⁻² S cm⁻¹) imidazole polymeric ionic liquid interface layer (1-carboxymethyl-3-vinylimidazolium bromide monomer, CVBr) for Zn metal protection is designed. The N⁺ atom of imidazole rings is connected by chains to form the cavities and the anions are confined within these cavities. Thus, the hindering effect of surrounding units on the anions leads to the subdiffusive regime, which inhibits the diffusion of SO₄²⁻ in interface and increases Zn²⁺ transference number. Besides, the polycation-anion coordination mechanism of PolyCVBr ensures accelerated Zn²⁺ transition and realizes rapid internal Zn²⁺ migration channel. As a result, the Zn@CVBr||AM symmetry cells deliver high bulk ionic conductivity (4.42 × 10⁻² S cm⁻¹) and high Zn²⁺ transference number (tZn²⁺ = 0.88) simultaneously. The Zn@CVBr||AM-NaV₃O₈ pouch cells display the capacity retention of 88.9% after 190 cycles under 90° bending, verifying their potential practical application.     

基于单次快拍的双基地MIMO雷达多目标角度估计方法

该文提出了一种双基地MIMO雷达体制下,利用单次快拍的回波数据进行多目标2维发射角(DOD)和2维接收角(DOA)联合估计的新方法。首先对等效接收阵数据的自相关矩阵进行发射分集平滑实现接收角(DOA)的估计,然后对等效发射阵数据的自相关矩阵进行接收分集平滑实现发射角(DOD)的估计,最后通过最大似然法完成两种角度的配对。该算法仅用一个时域快拍的数据实现了多目标回波的解相干,对发射和接收阵型有着广泛的适应性,同时为高速机动目标的角度测量提供了一种新的思路,仿真实验表明了该算法的有效性。     

Tuning a Solvation Structure of Lithium Ions Coordinated with Nitrate Anions through Ionic Liquid-Based Solvent for Highly Stable Lithium Metal Batteries

Rational design of promising electrolyte is considered as an effective strategy to improve the cycling stability of lithium metal batteries (LMBs). Here, an elaborately designed ionic liquid-based electrolyte is proposed that is composed of lithium bis(trifluoromethanesulfonyl)imide as the lithium salt, 1-ethyl-3-methylimidazolium nitrate ionic liquid ([EMIm][NO₃] IL) and fluoroethylene carbonate (FEC) as the functional solvents, and 1,2-dimethoxyethane (DME) as the diluent solvent. Using [EMIm][NO₃] IL as the solvent component facilitates a special Li⁺-coordinated NO₃⁻ solvation structure, which enables the continues electrochemical reduction of solvated NO₃⁻ and the formation of remarkably stable and conductive solid electrolyte interface. With FEC as another functional solvent and DME as the diluent solvent, the formulated electrolyte delivers high oxidative stability and ionic conductivity, and endows improved electrochemical reaction kinetics. Therefore, the formulated electrolyte demonstrates exceedingly reversible and stable Li stripping/plating behavior with high average Coulombic efficiency (98.8%) and ultralong cycling stability (3500 h). Notably, the high-voltage Li|LiNi_0.8Co_0.1Mn_0.1O₂ full cell with IL-based electrolyte exhibits enhanced cyclability with a capacity retention of 65% after 200 cycles under harsh conditions of low negative/positive ratio (3.1) and lean electrolyte (2.5 µL mg⁻¹). This study creates the first NO₃⁻-based ionic liquid electrolyte and evokes the avenue for practical high-voltage LMBs.     

基于虚拟现实环境的脑机接口技术研究进展

将脑-机接口(brain-computer interface,BCI)技术与虚拟现实(virtual reality,VR)相结合构成基于虚拟现实的脑-机接口(BCI-VR)新技术是最近在多媒体和娱乐领域出现的一种BCI应用新模式。BCI-VR兼取两者优势互补,同时又相互促进创新,显示出广阔应用前景。本文从BCI-VR系统基本构成、BCI对VR控制和VR对BCI影响等方面,较详细介绍了近年来BCI-VR的主要研究方法、研究进展和成就,并根据作者体会小结了目前存在的难点与未来的可能发展动向,以与读者交流、共同促进BCI-VR新技术的快速发展。