一种特殊DBF—PD米波雷达体制下的多目标检测方法

提出了一种特殊米波雷达体制下的多目标检测方法。该方法借助数字波束形成（ＤＢＦ）、脉冲多普勒（ＰＤ）和单脉冲技术在空域、时域、频域内完成目标测量。文中给出了系统框图、检测算法和仿真结果     

动目标检测雷达数字信号处理机内建自测试研究

提出了一种动目标检测雷达数字信号处理机内建自测试方法。该方法介于系统级和板级之间,集系统调试、在线测试和离线测试于一体,设计简单,易于实现。论证了处理机各个关键模块的具体测试方法。针对其中的“数据存储重排”模块和“ Ｆ Ｆ Ｔ 与求模”模块,计算了故障覆盖率。     

信息边界安全及我国的对策

进入９０年代以来,信息安全已居为各国十分重视的国家安全问题。本文作者在“信息安全”的基础上率先提出了“信息边界安全”的全新概念,并对信息边界最易受攻击 的“主要区段”以及我国应采取的对策作了介绍。     

格基约减算法及其应用

格基约减在许多应用上是一个非常有力的数学工具。本文详细介绍了有关格基约减算 法的概念、定义和著名的LLL算法,并在此基础上通过一个对低阶RSA算法的攻击过程对约减算法 的应用进行了简要介绍。     

小鼠在体皮下乳腺癌的太赫兹波成像检测研究

乳腺癌是女性常见癌症之一,乳腺癌区域的精准检测对乳腺癌的治疗有至关重要的作用。本文采用频率为2.52THz的连续太赫兹波反射式成像系统,对小鼠在体皮下乳腺癌模型进行了太赫兹波成像检测。研究结果表明,太赫兹波成像可以清晰识别出乳腺癌区域,且与肉眼可见肿瘤区域一致。在体乳腺癌区域的太赫兹波相对反射率高于正常组织,两者相对反射率差值高达15%。进一步,对距离皮肤表面不同深度的离体乳腺癌组织进行切片和苏木精-伊红(H&E)染色,作为金标准对照。结果发现乳腺癌区域的面积随着距离皮肤表面深度的增加而增大。通过将太赫兹波成像与H&E染色结果对比可知,在距离皮肤表面约460μm处,太赫兹波图像和H&E染色图中的肿瘤区域面积相等。由此可知,太赫兹波对在体皮下乳腺癌的探测深度大约在460μm左右,太赫兹波有望实现深部肿瘤的检测。     

Electrocatalytic Interlayer with Fast Lithium–Polysulfides Diffusion for Lithium–Sulfur Batteries to Enhance Electrochemical Kinetics under Lean Electrolyte Conditions

Lithium–sulfur batteries are promising energy‐storage devices because of their high theoretical energy densities. For practical Li–S batteries, reducing the amount of electrolyte used is essential for achieving the high energy densities. However, reducing the electrolyte amount leads to severe performance degradation, mainly because of sluggish deposition of discharge products (Li₂S) and the accompanying passivation issue that arise from the insulating nature of Li₂S. In this study, a lightweight, robust interlayer, with a 3D open structure and a low surface area is designed and fabricated. The structure facilitates electrolyte infiltration without trapping too much electrolyte. Moreover, the electrocatalytic Co nanoparticles embedded in the skeleton surface within the interlayer effectively promote Li ion diffusion, polysulfides conversion, and Li₂S deposition, and therefore enhance the electrochemical kinetics under lean electrolyte conditions. The mechanisms involved in the interlayer effects are investigated by microstructural characterizations, electrochemical performance tests, density functional theory calculations, and in situ X‐ray diffraction characterization. These results show the feasibility of using an interlayer strategy to improve the electrochemical performances of Li–S batteries under lean electrolyte conditions to potentially increase the practical energy densities of Li–S batteries.     

Recent Progress in Flexible and Stretchable Organic Solar Cells

Flexible and stretchable organic solar cells (OSCs) have attracted enormous attention due to their potential applications in wearable and portable devices. To achieve flexibility and stretchability, many efforts have been made with regard to mechanically robust electrodes, interface layers, and photoactive semiconductors. This has greatly improved the performance of the devices. State‐of‐the‐art flexible and stretchable OSCs have achieved a power conversion efficiency of 15.21% (16.55% for tandem flexible devices) and 13%, respectively. Here, the recent progress of flexible and stretchable OSCs in terms of their components and processing methods are summarized and discussed. The future challenges and perspectives for flexible and stretchable OSCs are also presented.     

Covalent 0D–2D Heterostructuring of Co9S8–MoS2 for Enhanced Hydrogen Evolution in All pH Electrolytes

Ultrasmall Co₉S₈ nanoparticles are introduced on the basal plane of MoS₂ to fabricate a covalent 0D–2D heterostructure that enhances the hydrogen evolution reaction (HER) activity of electrochemical water splitting. In the heterostructure, separate phases of Co₉S₈ and MoS₂ are formed, but they are connected by Co–S–Mo type covalent bonds. The charge redistribution from Co to Mo occurring at the interface enhances the electron‐doped characteristics of MoS₂ to generate electron‐rich Mo atoms. Besides, reductive annealing during the synthesis forms S defects that activates adjacent Mo atoms for further enhanced HER activity as elucidated by the density functional theory (DFT) calculation. Eventually, the covalent Co₉S₈–MoS₂ heterostructure shows amplified HER activity as well as stability in all pH electrolytes. The synergistic effect is pronounced when the heterostructure is coupled with a porous Ni foam (NF) support to form Co₉S₈–MoS₂/NF that displays superior performance to those of the state‐of‐the‐art non‐noble metal electrocatalysts, and even outperforms a commercial Pt/C catalyst in a practically meaningful, high current density region in alkaline (>170 mA cm^?2) and neutral (>60 mA cm^?2) media. The high HER performance and stability of Co₉S₈–MoS₂ heterostructure make it a promising pH universal alternative to expensive Pt‐based electrocatalysts for practical water electrolyzers.     

Recent Advances of Cell Membrane‐Coated Nanomaterials for Biomedical Applications

Surface modification of nanomaterials is essential for their biomedical applications owing to their passive immune clearance and damage to reticuloendothelial systems. Recently, a cell membrane‐coating technology has been proposed as an ideal approach to modify nanomaterials owing to its facile functionalized process and good biocompatibility for improving performances of synthetic nanomaterials. Here, recent advances of cell membrane‐coated nanomaterials are reviewed based on the main biological functions of the cell membrane in living cells. An overview of the cell membrane is introduced to understand its functions and potential applications. Then, the applications of cell membrane‐coated nanomaterials based on the functions of the cell membrane are summarized, including physical barrier with selective permeability and cellular communication via information transmission and reception processes. Finally, perspectives of biomedical applications and challenges about cell membrane‐coated nanomaterials are discussed.     

氨化温度对Si基GaN纳米结构质量的影响(英文)

通过磁控溅射技术在Si(111)衬底上沉积Ga2O3/Co薄膜,然后在不同温度下氨化制得GaN纳米结构。采用X射线衍射(XRD)、傅里叶红外吸收谱(FTIR)、扫描电子显微镜(SEM)、高分辨透射电镜(HRTEM)和光致发光谱(PL)对样品的结构、形貌和光学特性进行了表征。结果显示合成的GaN纳米结构具有六方纤锌矿结构,且纳米结构的生长受温度影响很大。PL谱显示在388nm处有一强的紫外发光峰,表明其在低维激光器件方面的应用优势。同时对纳米结构的生长机制进行了简单讨论。