一类直接式信息传输模型的安全可靠性设计

本文对通信系统中一类直接传输式的信息传输模型进行了安全可靠性设计。通过采用一种公开/秘密密钥算法相结合的动态加密系统,实现了信息传输安全性和实时性的有效统一。同时提出了一种把安全系统的运行阶段有机划分为正常运行阶段、种子密钥预置阶段和故障恢复阶段三个不同阶段的思想。系统除了具有良好的安全性、实时性等优点外,其独有的自适应能力、容错能力及故障恢复能力也保证了安全系统还具备高可靠性。     

微传感器制造中的硅-玻璃静电键合技术

介绍了硅－玻璃静电键合的基本原理,阐述了在自建静电键合设备上实现静电键合的过程,结合其在微机械传感器中的应用,讨论了粗糙表面键合技术。     

基于AD9244和PCI9054的虚拟无线电接收子系统

虚拟无线电是软件无线电技术一种新的发展趋势,基本思路是利用计算机取代传统软件无线电系统中的DSP芯片,一般采用直接中频采样技术,将采样结果通过PCI总线送入主机内存,由用户软件做后续的信号处理.本文讨论了欠采样技术在中频信号接收系统中的应用,由此提出了一种虚拟无线电接收子系统实现的硬件设计方案,然后对系统中重要芯片的性能进行了介绍,并对系统的控制过程进行了详细说明,最后简要介绍了一些注意事项.     

具有饱和非线性的非克尔光纤中自相位调制效应所致啁啾

在考虑光纤损耗下,从理论上推导出具有饱和非线性的非克尔光纤中自相位调制效应产生啁啾的解析表达式;并在计算机上模拟了光纤中啁啾的演变过程。结果表明,非克尔光纤中的饱和效应越强,自相位效应所产生的啁啾越小;随着光纤传输,啁啾不断增大;而且啁啾与光纤损耗、入射脉冲的峰值功率等因素有关。     

一种FBG载荷定位的温度补偿方法

在基于神经网络的光纤布喇格光栅(FBG)载荷定位系统中,由于测试区域内各个光栅所处的温度大致相同,如果将载荷定位系统中FBG的波长变化量两两组合,然后按一定的比例相减,将它们的差值作为神经网络的训练样本,则可抵消温度所引起的波长漂移,提高了在温度变化时FBG载荷定位系统的准确度。实验证实该方法可获得较准确的判定结果。     

A Hetero-Layered,Mechanically Reinforced,Ultra-Lightweight Composite Polymer Electrolyte for Wide-Temperature-Range,Solid-State Sodium Batteries

The practical use of polyethylene oxide polymer electrolyte in the solid-state sodium metallic batteries (SSMBs) suffers from the retard Na⁺ diffusion at the room temperature, mechanical fragility as well as the oxidation tendency at high voltages. Herein, a hetero-layered composite polymeric electrolyte (CPE) is proposed to enable the simultaneous interfacial stability with the high voltage cathodes (till 4.2 V) and Na metallic anode. Being incorporated within the polymer matrix, the sand-milled Na₃Zr₂Si₂PO₁₂ nanofillers and nanocellulose scaffold collectively endow the thin-layer (25 µm), ultralightweight (1.65 mg cm⁻²) CPE formation with an order of magnitude enhancement of the mechanical strength (13.84 MPa) and ionic conductivity (1.62 × 10⁻⁴ S cm⁻¹) as compared to the pristine polymer electrolyte, more importantly, the improved dimension stability up to 180 °C. Upon the integration of the hetero-layered CPE with the iron hexacyanoferrate FeHCF cathode (1 mAh cm⁻²) and the Na foil, the cell model can achieve the room-temperature cycling stability (93.73% capacity retention for 200 cycles) as well as the high temperature tolerance till 80 °C, which inspires a quantum leap toward the surface-wetting-agent-free, energy-dense, wide-temperature-range SSMB prototyping.     

A Universal Descriptor in Determining H2 Evolution Activity for Dilute Aqueous Zn Batteries

Large-scale energy storage with aqueous Zn batteries (AZBs) have bright future, but their practical application is impeded by H₂ evolution reaction (HER), which results in poor stability of Zn–metal anodes. Here, using linear sweep voltammetry in dilute salt aqueous electrolytes, it is discovered that as the salt concentration decreases, HER is gradually suppressed, which is contrary to prior beliefs. Combining calculations and experiments, it is demonstrated that HER derives predominantly from the sum of Zn²⁺-solvated water rather than the average amount of water in the Zn²⁺-solvation structural unit or free water without interaction with Zn²⁺, which answers the puzzle from above. This result, which differs fundamentally from the previous understandings, sheds new light on the mysterious role of water chemistry in controlling HER and contributes to a more rational design of advanced electrolytes for AZBs.     

一种复杂过程与复合对象三维建模的实现方法

伴随着虚拟现实技术研究的深入和应用的推广,建模方法作为核心内容也会应用于越来越复杂的系统。现有的建模技术将模型,运动和模型与周围环境的关系相互孤立,这不利用高效和快捷地实现复杂系统。针对这些问题,文章首先使用过程建模方法对复杂系统层次化,然后提出关系建模方法对模型,运动和关系建立标准结构,最后针对复杂过程和复合对象两种应用提出实现方法,验证了方法的可行性和有效性。     

Tunable Optical Mode Ferromagnetic Resonance in FeCoB/Ru/FeCoB Synthetic Antiferromagnetic Trilayers under Uniaxial Magnetic Anisotropy

Ferromagnetic resonance (FMR) is one of the most important characteristics of soft magnetic materials, which practically sets the maximum operation speed of these materials. There are two FMR modes in exchange coupled ferromagnet/nonmagnet/ferromagnet sandwich films. The acoustic mode has relatively lower frequency and is widely used in radio‐frequency/microwave devices, while the optical mode is largely neglected due to its tiny permeability even though it supports much higher frequency. Here, a realistic method is reported to enhance the permeability in the optical mode to an applicable level. FeCoB/Ru/FeCoB trilayers are carefully engineered with both uniaxial magnetic anisotropy and antiferromagnetic interlayer exchange coupling. This special magnetic structure exhibits a high optical mode frequency up to 11.28 GHz and a maximum permeability of 200 at resonance. An abnormally low inverse switch field (<200 Oe, less than 1/5 of the single layer) is observed which can effectively switch the system from optical mode with higher frequency into acoustic mode with lower frequency. The optical mode frequency and inverse switch field can be controlled by tailoring the interlayer coupling strengths and the uniaxial anisotropy fields, respectively. The tunable optical mode resonance thus can increase operation frequency while reduce operation field overhead in FMR based devices.     

基于扩散小波的社会网络多尺度分析简

针对社会网络中的同质性关系提出一个基于扩散小波的多尺度分析框架,通过局部相似性度量构造扩散算子,在统一的框架下对社会网络中的结构、内容、用户行为等进行多尺度分析。在合成和真实网络数据上进行实验,与典型算法的对比表明,本算法在无参数的条件下快速收敛并得到更好的结果。