探头修正用坐标变换

在天线近场测量中探头的波瓣图影响需要修正,修正以后才能获得被测天线的远场波瓣图。大线波瓣回常使用球坐标（θ,Φ）来表示,但是在球坐标系（θ,Φ）中进行探头效应修正十分不便,而且在某些角度上探头效应修正精度差。另外,为适合不同远场波瓣图的输出坐标系要求,也需要作坐标变换。如果需要也可以再返回到（θ,Φ）球坐标系中去。     

Oxygen Vacancy Modulation of Bimetallic Oxynitride Anodes toward Advanced Li‐Ion Capacitors

Binary metal oxides (such as NiCo₂O₄) are regarded as attractive electrode materials for advanced energy storage devices since they offer more electrochemical activity and higher capacity than monometal oxide. However, the volume expansion and low electronic conductivity are the main bottleneck seriously hindering their application. To overcome these barriers, a novel strategy that introduces a bimetallic oxynitride layer (NiCoON) with oxygen vacancy to the surface of NiCo₂O₄ nanowires as an anode for Li‐ion capacitors (LICs) is proposed. The oxygen vacancy on the surface and the modulation of multiple valence states are investigated by the electron paramagnetic resonance, X‐ray photoelectron spectroscopy characterization, and first‐principles calculation. Benefiting from the merits of substantially improved electrical conductivity and increased concentration of active sites, the optimized NiCoON electrode delivers remarkable capacity (1855 mAh g^?1 at 0.2 A g^?1) and rate performance. The LIC device assembled by NiCoON anodes and N‐doped carbon nanowire cathodes delivers excellent rate capability, high energy density (148.5 Wh kg^?1), and outstanding power density (30 kW kg^?1). This study provides a new pathway for developing bimetallic oxides with an improved performance in electrochemical energy storage, conversion fields, and beyond.     

Ru Species Supported on MOF‐Derived N‐Doped TiO2/C Hybrids as Efficient Electrocatalytic/Photocatalytic Hydrogen Evolution Reaction Catalysts

The development of efficient catalysts is of great importance for hydrogen evolution reaction (HER) of water splitting via electrocatalytic/photocatalytic processes to remediate the current severe environmental and energy problems. By aid of the stabilization effects of uncoordinated groups and inherent pore‐confinement of amine‐functionalized metal–organic frameworks (NH₂‐MIL‐125), two forms of Ru species including nanoparticles (NPs) and/or single atoms (SAs) can be firmly embedded in NH₂‐MIL‐125 derived N‐doped TiO₂/C support (N‐TC), and thus obtain two kinds of samples named Ru‐NPs/SAs@N‐TC and Ru‐SAs@N‐TC, respectively. In the synthetic process, the initial feeding amount of Ru³⁺ ions not only strongly determines the final size and dispersion states of Ru species but also the morphology and defective structures of N‐TC support. Impressively, Ru‐NPs/SAs@N‐TC exhibit superior catalytic activities to Ru‐SAs@N‐TC for either electrocatalytic or photocatalytic HER. This should be attributed to its larger specific surface area and benefiting from synergistic coupling of Ru NPs and Ru SAs. It is envisioned that the present work can provide a new avenue for development of high‐efficiency and multifunctional hybrid catalysts in sustainable energy conversion.     

移动WiMAX与Wi-Fi融合关键问题分析

无线接入互联网和无线多媒体数据业务的市场需求推动了无线通信技术的快速发展,通信技术宽带化、IP化、移动化成为未来的发展趋势.其中具有代表性的技术就是:Wi-Fi和移动WiMAX技术.本文从市场、技术、运营的角度来分析移动WiMAX和Wi-Fi的定位,探讨二者融合的可行性并给出建议.     

Multistage second-order microring-resonator filters with box-like spectral responses and relaxed fabrication tolerances

We demonstrate an optical filter based on multistage second-order microring resonators (MRs) with box-like spectral responses. Compared with single-stage high-order optical filters with the same number of MRs, the demonstrated structure has comparable performances in the aspects of passband flatness, rolling-off slope and insertion loss. Moreover, the architecture relaxes the fabrication tolerance, electrical wiring and tuning difficulty since there are only two MRs in each stage. We experimentally demonstrate this kind of optical filter with five stages, which shows a 3-dB bandwidth of ~17 GHz, a rolling-off slope of ~5 dB/GHz and an on-chip insertion loss of ~6 dB.     

飞秒激光刻蚀增强非晶硅薄膜太阳电池性能的研究

通过恒速移动线偏振飞秒激光焦点对非晶硅(a-Si) pin型薄膜太阳电池n型硅膜表面进行绒化刻蚀处理,形成不同周期间隔“凹槽”状结构.采用扫描电子显微镜(SEM)和X射线衍射仪(XRD)对刻蚀后薄膜表面形貌进行了表征,证实了刻蚀区域表面能够诱导晶态多孔微结构形成.比较了飞秒激光刻蚀前后a-Si太阳电池的光电转换效率(η)、开路电压、短路电流密度和填充因子.结果表明,当飞秒激光脉冲能量为0.75 J/cm2、刻蚀周期间隔为15μm时,太阳电池光电转换效率达到14.9％,是未经过激光刻蚀处理电池光电转换效率的1.87倍.同时,反射吸收谱表明,电池表面多孔“光俘获”微结构的形成对其光电转换效率的提高起到了关键作用.     

掺Yb相移光纤光栅形成过程的分析

研究了用二次曝光法制作掺Yb相移光纤光栅的实验过程 ,并对相移光纤光栅制作过程中出现次峰的情况进行了理论分析。合理地解释了该现象     

MEMS电磁执行器CoNi MnP永磁体阵列的制备

永磁材料在微电子机械系统 (MEMS)器件中具有重要的应用价值 ,例如微型开关、微型继电器以及微泵、微阀中作电磁执行器等。本文介绍了CoNiMnP永磁体阵列的制备技术 ,给出了工艺制备的实验条件 ,并利用SEM分析了阵列的表面形貌 ,电子能谱分析了永磁材料组分。实验结果表明 ,得到了很好的CoNiMnP永磁体阵列结构 ,具有较高的矫顽磁力的材料组分比例 :Co 85 %、Ni14 %。     

电子对抗指挥自动化系统等级互操作研究

本文就电子对抗指挥自动化系统等级互操作的概念进行了阐述 ,指出在信息作战环境下实施等级互操作的必要性 ,并对电子对抗指挥自动化系统的互操作等级层次进行了分析     

化学复合镀层激光处理研究

研究了激光处理对Ni-P -SiC化学复合镀层的影响。借助于扫描电镜、能谱仪、X射线衍射、显微硬度计等设备对激光处理后复合镀层的表面形貌、组织结构及性能进行了综合分析。结果表明 ,对复合镀层进行激光处理可以获得与炉内加热同样的镀层硬度 ,且当激光功率 4 0 0W ,扫描速度 1.5m /min时 ,镀层硬度高于炉内加热的硬度