国外战术导弹半实物仿真试验验证能力发展分析

半实物仿真是战术导弹等先进武器装备在研制试样、性能评估、作战演练中必不可少的主要仿真方法和手段。从多物理场/控制耦合、导航、多模/宽谱段制导、导引头抗干扰、靶场试验等五个方面,介绍了国外战术导弹半实物仿真试验设备、试验技术的具体情况,分析了其半实物仿真验证能力的发展现状及发展趋势,提出了战术导弹半实物仿真应重点关注在复杂战场环境、新型物理效应、多弹协同/多体飞行器协同等方面的能力建设,分析结果可对未来战术导弹半实物仿真能力建设发展具有借鉴意义。     

表面裂纹结构断裂失效概率计算的线弹簧-响应面法

将线弹簧模型法和响应面法相结合,建立含表面裂纹结构断裂失效概率的计算方法。考虑材料特性、外载荷和裂纹尺寸等参数的不确定性,以含表面裂纹平板为例进行计算,得出失效概率和可靠度指标。与Monte Carlo法结果进行对比,表明该方法合理有效,在大大减小计算量的同时,能够保证很高的精度,适合工程实际应用。     

Cohesively Enhanced Conductivity and Adhesion of Flexible Silver Nanowire Networks by Biocompatible Polymer Sol–Gel Transition

Silver nanowire (AgNW) networks are a promising candidate to replace indium tin oxide (ITO) as transparent conductors. In this paper, a novel transparent composite conductor composed of AgNW/biocompatible alginate gel on a flexible polyethylene terephthalate (PET) substrate, with synchronously enhanced adhesion and reduced resistivity, is prepared without high‐temperature annealing. The sheet resistance of the flexible AgNW/PET film reduces from 300 to 50.3 Ohm sq^?1 at transmittance of 94%. The optical and electrical performance is superior to that obtained from the flexible ITO film on PET. Meanwhile, the sheet resistance does not show great change after tape test, suggesting a good adhesion of AgNW to the polymer substrate. Moreover, the AgNW composite film shows a good stability to resist long‐term storage, solvent damage, and ultrasonication. Finally, polymer solar cells employing the composite AgNW film as the electrode are realized, displaying an efficiency of 2.44%.     

基于STC12C5A60S2的多功能测量系统设计

本文介绍了基于STC12C5A60S2单片机的多功能测量系统,系统实现对空气温湿度、CO2浓度以及室内光照强度的检测,同时具有万年历时钟显示功能.阐述了系统硬件和软件的整体设计方案、器件选型、单元电路设计及整体电路连接.通过理论分析及实验证明能有效测出温湿度、CO2含量及室内光照强度,测量准确,参数调节方便,使用效果良好.     

Performance Analysis of Colocated MIMO Radars with Randomly Distributed Arrays in Compound-Gaussian Clutter

This paper focuses on the target detection problem for colocated MIMO radar with randomly distributed arrays in the presence of compound-Gaussian clutter with unknown Power Spectral Density (PSD). First, we derive the Generalized Likelihood Ratio Test (GLRT) assuming known covariance structure, and then, three different covariance estimation strategies, i.e., Sampled Covariance Matrix (SCM), Normalized Sampled Covariance Matrix (NSCM), and Fixed Point Estimation (FPE) Matrix, are introduced in place of the exact one to make the derived GLRT fully adaptive. Thorough numerical evaluations of the detection performance are provided and discussed.     

Performance Analysis of Two-Way Hybrid Decode-and-Amplify Relaying Scheme with Relay Selection for Secondary Spectrum Access

In this paper, we propose and analyze the outage probability of a two-way hybrid decode-and-amplify relaying scheme with relay selection for secondary spectrum access. In this scheme, a secondary network is co-located and uses the same spectrum as the primary network. The primary network is comprised of two primary terminals that attempt to transmit signals to one another; the secondary network is comprised of M secondary transmitter-receiver pairs (ST-SR). One of the secondary transmitters chosen to cooperate with the primary network uses a hybrid decode-and-amplify forward technique in order to relay primary and secondary signals. We derive expressions for the outage probability of the primary network as well as the secondary network over a Rayleigh fading channel. Simulation results are presented to verify theoretical analyses and to compare the performance of the proposed protocol to that of a two-way direct transmission protocol.     

Bend,Twist, and Turn: First Bendable and Malleable Toughened PLA Green Composites

The future of green electronics possessing great strength and toughness proves to be a promising area of research in this technologically advanced society. This work develops the first fully bendable and malleable toughened polylactic acid (PLA) green composite by incorporating a multifunctional polyhydroxybutyrate rubber copolymer filler that acts as an effective nucleating agent to accelerate PLA crystallization and performs as a dynamic plasticizer to generate massive polymer chain movement. The resultant biocomposite exhibits a 24‐fold and 15‐fold increment in both elongation and toughness, respectively, while retaining its elastic modulus at >3 GPa. Mechanism studies show the toughening effect is due to an amalgamation of massive shear yielding, crazing, and nanocavitation in the highly dense PLA matrix. Uniquely distinguished from the typical flexible polymer that stretches and recovers, this biocomposite is the first report of PLA that can be “bend, twist, turn, and fold” at room temperature and exhibit excellent mechanical robustness even after a 180° bend, attributes to the highly interconnected polymer network of innumerable nanocavitation complemented with an extensively unified fibrillar bridge. This unique trait certainly opens up a new horizon to future sustainable green electronics development.     

共振多光子电离探测芳香烃污染物对比实验研究

本文用两种不同的方法对同期制备的不同浓度的苯、甲苯、二甲苯及其混合气和摩托车尾气三类样品分别进行了对比实验,实验验证了多光子电离所得实验数据的可靠性及其测量精确性,同时可以看出多光子电离方法所具有的快速、实时在线和多组分同时探测的优越性。     

Soft Robotic-Adapted Multimodal Sensors Derived from Entirely Intrinsic Self-Healing and Stretchable Cross-Linked Networks

Flexible sensing technologies that play a pivotal role in endowing robots with detection capabilities and monitoring their motions are impulsively desired for intelligent robotics systems. However, integrating and constructing reliable and sustainable flexible sensors with multifunctionality for robots remains an everlasting challenge. Herein, an entirely intrinsic self-healing, stretchable, and attachable multimodal sensor is developed that can be conformally integrated with soft robots to identify diverse signals. The dynamic bonds cross-linked networks including the insulating polymer and conductive hydrogel with good comprehensive performances are designed to fabricate the sensor with prolonged lifespan and improved reliability. Benefiting from the self-adhesiveness of the hydrogel, strong interfacial bonding can be formed on various surfaces, which promotes the conformable integration of the sensor with robots. Due to the ionic transportation mechanism, the sensor can detect strain and temperature based on piezoresistive and thermoresistive effect, respectively. Moreover, the sensor can work in triboelectric mode to achieve self-powered sensing. Various information can be identified from the electrical signals generated by the sensor, including hand gestures, soft robot crawling motions, a message of code, the temperature of objects, and the type of materials, holding great promise in the fields of environmental detection, wearable devices, human-machine interfacing, and robotics.