一种适用于复合制导的中末制导弹道交接班方法

导弹武器系统的发展趋势是由单一制导模式向复合制导过渡,而中末制导的可靠交接班是复合制导的关键步骤。针对复合制导中的中末制导弹道交接班问题,在分析中末制导弹道平滑过渡约束条件的基础上,提出了一种简单有效的线性中末制导交接班算子,详细计算了平滑算子的加权系数。通过直升机载空地导弹的中末制导弹道交接班的仿真试验,验证所提方法的可行性。试验结果表明,在较小中末制导律差异条件下,所提算子可实现弹道的平滑过渡和良好衔接。     

一种热塑态真空振动装药工艺

为提高弹药产品质量及生产过程的本质安全度,改善现有热塑态装药生产条件,针对常规热塑态装药方法存在的缺陷,提出一种将真空振动装药法引入热塑态装药工艺设备的设计方案。综合应用自动控制技术、大型真空室振动装药技术,实现了对弹药产品热塑态装药过程的自动控制,建立了热塑态装药生产线,并在某产品试制中得到成功应用。实践证明:该生产线提高了弹药装药质量和本质安全度,具有较高的经济效益和社会效益。     

基于多智能体强化学习的无人车分布式路径规划方法

在危险系数较高的救援、勘察或补给等重要任务中,为避免人员伤亡,需要无人车具备自主探索并协同到达多个目标位置的能力.基于此,提出一种基于多智能体强化学习的无人车分布式路径规划模型,通过集中训练方式生成无人车的行驶策略.仿真结果证明了该方法的有效性.     

Regulating Intercalation of Layered Compounds for Electrochemical Energy Storage and Electrocatalysis

Layered materials have received extensive attention for widespread applications such as energy storage and conversion, catalysis, and ion transport owing to their fast ion diffusion, exfoliative feature, superior mechanical flexibility, tunable bandgap structure, etc. The presence of large interlayer space between each layer enhances intercalation of the guest ion or molecule, which is beneficial for fast ion diffusion and charge transport along the channels. This intercalation reaction of layered compounds with guest species results in material with improved mechanical and electronic properties for efficient energy storage and conversion, catalysis, ion transport, and other applications. This review extensively discusses the intercalation of guest ionic or molecular species into layered materials used for various types of applications. It assesses the intercalation strategies, mechanism of ionic or molecular intercalation reactions, and highlights recent advancements. The electrochemical performances of several typical intercalated materials in batteries, supercapacitors, and electrocatalytic systems have been thoroughly discussed. Moreover, the challenges in the design and intercalation of layered materials, as well as prospects of future development are highlighted.     

2D Metallic Transition-Metal Dichalcogenides: Structures,Synthesis, Properties,and Applications

2D materials and the associated heterostructures define an ideal material platform for investigating physical and chemical properties, and exhibiting new functional applications in (opto)electronic devices, electrocatalysis, and energy storage. 2D transition metal dichalcogenides (2D TMDs), as a member of the 2D materials family including 2D semiconducting TMDs (s-TMDs) and 2D metallic/semimetallic TMDs (m-TMDs) have attracted considerable attention in the scientific community. Over the past decade, the 2D s-TMDs have been extensively researched and reviewed elsewhere. Because of their distinctive physical properties including intrinsic magnetism, charge-density-wave order and superconductivity, and potential applications, such as high-performance electronic devices, catalysis, and as metal electrode contacts, 2D m-TMDs have grabbed widespread attention in recent years. However, reviews demonstrating the m-TMDs systematically and comprehensively have been rarely reported. Here, the recent advances in 2D m-TMDs in the aspects of their unique structures, synthetic approaches, distinctive physical properties, and functional applications are highlighted. Finally, the current challenges and perspectives are discussed.     

Recent progress of physical failure analysis of GaN HEMTs

Gallium nitride (GaN)-based high-electron mobility transistors (HEMTs) are widely used in high power and high frequency application fields,due to the outstanding physical and chemical properties of the GaN material.However,GaN HEMTs suffer from degradations and even failures during practical applications,making physical analyses of post-failure devices extremely significant for reliability improvements and further device optimizations.In this paper,common physical characterization techniques for post failure analyses are introduced,several failure mechanisms and corresponding failure phenomena are reviewed and summarized,and finally device optimization methods are discussed.     

引线框氧化与可靠性关系的研究

铜材料引线框架具有良好的导电导热性能,同时具备良好的机械性能和较低成本,但是由于框架和塑封料之间较差的粘结力在回流焊时容易造成封装体开裂。文章研究了铜框架氧化膜的特性,以及氧化膜对半导体封装的可靠性影响。根据试验,氧化膜会随着时间温度而增加,当氧气含量低于1%时增加缓慢。当氧化膜的厚度超过20nm时,塑封料与氧化铜之间的结合力就会显著下降,同时交界面的分层也会加剧。最后针对氧化膜厚度受控的产品做回流焊测试,确认是否有开裂,结果表明与结合力测试相符。氧化膜的厚度需要低于42.5nm,可以提高在reflow时的抗开裂性能。     

Fatigue-Resistant Conducting Polymer Hydrogels as Strain Sensor for Underwater Robotics

Conducting polymer hydrogels are widely used as strain sensors in light of their distinct skin-like softness, strain sensitivity, and environmental adaptiveness in the fields of wearable devices, soft robots, and human-machine interface. However, the mechanical and electrical properties of existing conducting polymer hydrogels, especially fatigue-resistance and sensing robustness during long-term application, are unsatisfactory, which severely hamper their practical utilities. Herein, a strategy to fabricate conducting polymer hydrogels with anisotropic structures and mechanics is presented through a combined freeze-casting and salting-out process. The as-fabricated conducting polymer hydrogels exhibit high fatigue threshold (>300 J m⁻²), low Young's modulus (≈100 kPa), as well as long-term strain sensing robustness (over 10 000 cycles). Such superior performance enables their application as strain sensors to monitor the real-time movement of underwater robotics. The design and fabrication strategy for conducting polymer hydrogels reported in this study may open up an enticing avenue for functional soft materials in soft electronics and robotics.     

New Polymerized Small Molecular Acceptors with Non-Aromatic π-Conjugated Linkers for Efficient All-Polymer Solar Cells

Developing new polymerized small molecular acceptor (PSMA) is pivotal for improving the performance of all-polymer solar cells. On the basis of this newly developed CH-series small molecule acceptors, two PSMAs are reported herein (namely PZC16 and PZC17, respectively). To reduce the molecular torsion caused by the traditional aromatic π-bridges, non-aromatic conjugated units (ethynyl for PZC16 and vinylene for PZC17) are adopted as the linkers and their effect on the photo-physical properties as well as the device performance are systematically investigated. Both polymer acceptors exhibit co-planar molecular conformation, along with broad absorption ranges and suitable energy levels. In comparison with the PM6:PZC16 film, the PM6:PZC17 film exhibits more uniform phase separation in morphology with a distinct bi-continuous network and better crystallinity. The PM6:PZC17-binary-based devices exhibit a satisfactory PCE of 16.33%, significantly higher than 9.22% of the PZC16-based devices. Impressively, PM6:PZC17-based large area device (ca. 1 cm²) achieves an excellent PCE of 15.14%, which is among the top performance for reported all-polymer solar cells (all-PSCs).