Stabilizing Polymer–Lithium Interface in a Rechargeable Solid Battery

Solid polymer electrolytes (SPEs) are promising candidates for developing high‐energy‐density Li metal batteries due to their flexible processability. However, the low mechanical strength as well as the inferior interfacial regulation of ions between SPEs and Li metal anode limit the suppress ion of Li dendrites and destabilize the Li anode. To meet these challenges, interfacial engineering aiming to homogenize the distribution of Li⁺/electron accompanied with enhanced mechanical strength by Mg₃N₂ layer decorating polyethylene oxide is demonstrated. The intermediary Mg₃N₂ in situ transforms to a mixed ion/electron conducting interlayer consisting of a fast ionic conductor Li₃N and a benign electronic conductor Mg metal, which can buffer the Li⁺ concentration gradient and level the nonuniform electric current distribution during cycling, as demonstrated by a COMSOL Multiphysics simulation. These characteristics endow the solid full cell with a dendrite‐free Li anode and enhanced cycling stability and kinetics. The innovative interface design will accelerate the commercial application of high‐energy‐density solid batteries.     

角抽运优化及辐射平衡激光器增益介质设计

角抽运能够避免使用抽运光高透激光高反的双色镜,并且对于低掺杂浓度的激光晶体仍然具有可以接受的吸收效率,因此该抽运方案适合辐射平衡激光器(RBL)较为苛刻的抽运要求.为确保抽运光不会从增益介质的角边泄漏,对角抽运方案中的晶体宽度给出了进一步的优化公式.在992.8 nm抽运光波长下,针对用于辐射平衡激光器的掺杂原子数分数为5%的Yb:KGW激光晶体,利用光线追迹法分别对不使用和使用高温熔合技术的两种角抽运设计方案进行了数值模拟计算.根据抽运吸收效率和均匀性等设计要求,两种角抽运方案中最佳入射角度均为45°,最佳抽运全反射次数值均为1,但是使用高温熔合技术比不使用该技术会使抽运效率提高约20%.     

电信级IP QoS的研究

在网络发展和业务应用需求的双重驱动下,电信级IPQoS作为实现多业务网络的关键技术得到了越来越多的关注。本文针对电信级IPQoS的相关问题,包括电信级IPQoS的必要性、研究和应用的现状、电信级IPQoS的框架模型进行了思考和研究,并对IPQoS的发展趋势进行了展望。     

MANET接入技术研究

以移动AdHoc网络(MobileAdHocNetworks)的接入技术为研究对象,介绍了该网络的特点及其采用的各种接入技术,并以双忙音多址(DBTMA)和RTS/CTS两种接入技术为例,比较了它们对网络性能的影响,最后是对MANET接入技术的总结。     

Field dependence of impact ionization coefficients in In/sub 0.53/Ga/sub 0.47/As

Electron and hole ionization coefficients in In/sub 0.53/Ga/sub 0.47/As are deduced from mixed carrier avalanche photomultiplication measurements on a series of p-i-n diode layers, eliminating other effects that can lead to an increase in photocurrent with reverse bias. Low field ionization is observed for electrons but not for holes, resulting in a larger ratio of ionization coefficients, even at moderately high electric fields than previously reported. The measured ionization coefficients are marginally lower than those of GaAs for fields above 250 kVcm/sup -1/, supporting reports of slightly higher avalanche breakdown voltages in In/sub 0.53/Ga/sub 0.47/As than in GaAs p-i-n diodes.     

Automatic gait recognition based on statistical shape analysis

Gait recognition has recently gained significant attention from computer vision researchers. This interest is strongly motivated by the need for automated person identification systems at a distance in visual surveillance and monitoring applications. The paper proposes a simple and efficient automatic gait recognition algorithm using statistical shape analysis. For each image sequence, an improved background subtraction procedure is used to extract moving silhouettes of a walking figure from the background. Temporal changes of the detected silhouettes are then represented as an associated sequence of complex vector configurations in a common coordinate frame, and are further analyzed using the Procrustes shape analysis method to obtain mean shape as gait signature. Supervised pattern classification techniques, based on the full Procrustes distance measure, are adopted for recognition. This method does not directly analyze the dynamics of gait, but implicitly uses the action of walking to capture the structural characteristics of gait, especially the shape cues of body biometrics. The algorithm is tested on a database consisting of 240 sequences from 20 different subjects walking at 3 viewing angles in an outdoor environment. Experimental results are included to demonstrate the encouraging performance of the proposed algorithm.     

大规模定制环境下 ERP 的发展

ERP─EnterpriseResourcePlanning企业资源计划系统 ,是指建立在信息技术基础上 ,以系统化的管理思想 ,为现代企业决策层及员工提供决策运行手段的管理平台。从竞争环境的角度出发 ,提出了大规模定制已经逐渐成熟并最终取代大规模生产成为新的生产经营模式的观点 ,同时 ,分析了在大规模定制下传统ERP的局限 ,从管理和技术的角度探讨新一代ERP的特点及发展。     

采用全对称测试结构的超薄单晶硅薄膜热导率测亮

改进了传统稳态加热法的测试结构,设计了带隔离槽的全对称悬空薄膜测试结构,并使用有限元工具对测试结构进行了优化.测量了室温下50和80nm厚度的单晶硅薄膜的横向热导率,分别为32和38W/(m·K),其相对体硅热导率(148W/(m·K))有明显下降,实验结果与BTE(Boltzmann transport equation)的理论预测曲线吻合得很好.     

数值分析渐变DBR对垂直腔面发射激光器谐振腔模的影响

通过数值分析研究了含线性渐变层的Al0.9Ga0.1As/AlyGa1-yAs/GaAs/AlxGa1-xAS DBR的光学特性及其对VCSEL谐振腔光学特性的影响,建立了渐变型DBR渐变层厚度与折射率的关系,通过特征矩阵法计算了突变GaAs/Al0.9Ga0.1AS DBR和渐变型DBR的反射谱和反射相移,分析了渐变层对DBR反射率和反射相移的影响.对渐变型DBR,要使VCSEL谐振腔满足中心波长相位匹配条件,还需要在DBR靠近谐振腔一侧的最前面增加一定厚度的渐变层,称为相位匹配层.通过计算,我们得到了使VCSEL谐振腔满足相位匹配条件时均匀层和相位匹配层的厚度.     

一种新颖的应变Si沟道 pMOSFET制作技术

在应变Si沟道异质结场效应晶体管(HFET)制作过程中,引入分子束外延(MBE)低温Si(LT-Si)技术,大大减少了弛豫SiGe层所需的厚度.TEM结果表明,应变Si层线位错密度低于106cm-2.原子力显微镜(AFM)测试表明,其表面均方粗糙度小于1.02nm.器件测试结果表明,与相同条件下的体Si pMOSFET相比,空穴迁移率提高了25%.