Hierarchical Magnetic Network Constructed by CoFe Nanoparticles Suspended Within “Tubes on Rods” Matrix Toward Enhanced Microwave Absorption

Hierarchical magnetic-dielectric composites are promising functional materials with prospective applications in microwave absorption(MA)field.Herein,a three-dimension hierarchical“nanotubes on microrods,”core–shell magnetic metal–carbon composite is rationally constructed for the first time via a fast metal–organic frameworksbased ligand exchange strategy followed by a carbonization treatment with melamine.Abundant magnetic CoFe nanoparticles are embedded within one-dimensional graphitized carbon/carbon nanotubes supported on micro-scale Mo2N rod(Mo2N@CoFe@C/CNT),constructing a special multi-dimension hierarchical MA material.Ligand exchange reaction is found to determine the formation of hierarchical magnetic-dielectric composite,which is assembled by dielectric Mo2N as core and spatially dispersed CoFe nanoparticles within C/CNTs as shell.Mo2N@CoFe@C/CNT composites exhibit superior MA performance with maximum reflection loss of−53.5 dB at 2 mm thickness and show a broad effective absorption bandwidth of 5.0 GHz.The Mo2N@CoFe@C/CNT composites hold the following advantages:(1)hierarchical core–shell structure offers plentiful of heterojunction interfaces and triggers interfacial polarization,(2)unique electronic migration/hop paths in the graphitized C/CNTs and Mo2N rod facilitate conductive loss,(3)highly dispersed magnetic CoFe nanoparticles within“tubes on rods”matrix build multi-scale magnetic coupling network and reinforce magnetic response capability,confirmed by the off-axis electron holography.     

Glass crystallization making red phosphor for high-power warm white lighting

Rapid development of solid-state lighting technology requires new materials with highly efficient and stable luminescence, and especially relies on blue light p...     

影响挠性印制板插入损耗的几种因素

文章采用三层板叠构对高频通信用挠性印制板(FPCB)的插损进行测试对比,从制造FPCB的材料种类、材料厚度、胶层厚度、仿真设计、信号线过孔类型、盲孔质量,以及信号线阻抗值大小等多个因素总结出对最高频率到20GHz信号插损的影响.     

Effectiveness and petroleum geological significance of tectonic fractures in the ultra-deep zone of the Kuqa foreland thrust belt:a case study of the Cretaceous Bashijiqike Formation in the Keshen gas field

The buried depth of the gas-producing reservoir in the Kuqa foreland thrust belt of the Tarim Basin exceeds 6000 m.The average matrix porosity of the reservoir ...     

On the robustness of median sampling in noisy evolutionary optimization

Evolutionary algorithms (EAs) are a sort of nature-inspired metaheuristics,which have wide applications in various practical optimization problems.In these prob...     

冷轧带钢表面缺陷在线监测系统

介绍一套目前已在实验室中开发成功的冷轧带钢表面缺陷在线监测系统,该系统用于在线检测和识别冷轧带钢的表面缺陷.系统采用多个面阵CCD摄像头同步采集带钢表面的图像,并通过并行计算系统对图像进行分析和处理,以得到钢板表面的缺陷情况.系统在软件流程上进行了特殊的设计,以保证实时数据处理功能.经试验,系统对\     

Antibacterial Properties of an Austenitic Antibacterial Stainless Steel and Its Security for Human Body

An austenitic antibacterial stainless steel is reported in this paper. The very fine and dispersive ε-Cu precipitations in the matrix of the antibacterial steel after the antibacterial treatment endow the steel with antibacterial function. The antibacterial function is strong, long-term and broad-spectrum, and can be maintained even after repeated wear and long time dipping in water. The steel is safe for human body and could be used widely in daily application.     

从实践回应视角看科学发展观的科学性

实践是理论的根基和土壤.从实践视角审视科学发展观的科学内涵,可以提升科学发展观的学科地位.科学发展观是中国共产党在漫长实践中孕育出来的理论成果;是在实践背景下理论不断演绎提升的精华;其科学性为未来实践提供了理论支持.     

低压组合床重整装置腐蚀调查

重整装置腐蚀类型有高温H2腐蚀、高温H2-H2S腐蚀、有机酸腐蚀、H2S-HCl-H2O腐蚀,针对不同类型的腐蚀,应采取相应的防腐蚀措施。     

Simulation of aerodynamic performance affected by vortex generators on blunt trailing-edge airfoils

An investigation was carried out by numerical simulation on a wind turbine airfoil and a blunt trailing-edge airfoil with and without vortex generators (VGs), and the performance of the airfoils was analyzed. By the simulation of airfoil DU 91-W2-250 it was verified that the numerical method and model were credible. Based on this airfoil, a new one with a blunt trailing edge of 6% chord was blended by symmetrically adding thickness, and its characteristics curves were obtained through computing at key angle...