摘要：An atomic layer deposition （ALD） method has been employed to synthesize Fe3O4/graphene and Ni/graphene composites. The structure and microwave absorbing properties of the as-prepared composites are investigated. The surfaces of graphene are densely covered by Fe3O4 or Ni nanoparticles with a narrow size distribution, and the magnetic nanoparticles are well distributed on each graphene sheet without significant conglomeration or large vacancies. The coated graphene materials exhibit remarkably improved electromagnetic （EM） absorption properties compared to the pristine graphene. The optimal reflection loss （RL） reaches -46.4 dB at 15.6 GHz with a thickness of only 1.4 mm for the Fe3O4/graphene composites obtained by applying 100 cycles of Fe2O3 deposition followed by a hydrogen reduction. The enhanced absorption ability arises from the effective impedance matching, multiple interfacial polarization and increased magnetic loss from the added magnetic constituents. Moreover, compared with other recently reported materials, the composites have a lower filling ratio and smaller coating thickness resulting in significantly increased EM absorption properties. This demonstrates that nanoscale surface modification of magnetic particles on graphene by ALD is a very promising way to design lightweight and high-efficiency microwave absorbers.

摘要：Recently, the g-C3N4-based heterojunctions have been widely investigated for their greatly enhanced photogenerated carrier separation efficiency. However, most studies are based on the study of g-C3N4 powders. In this study, a novel TiN/C3N4/CdS nanotube arrays core/shell structure is designed to improve the photoelectrochemical catalytic performance of the g-C3N4-based heterojunctions. Among them, TiN nanotube arrays do not respond to simulated solar light, and thus only serve as an excellently conductive nanotube arrays backbone for supporting g-C3N4/CdS heterojunctions. g-C3N4 prepared by simple liquid atomic layer deposition, which possesses appropriate energy band position, mainly acts as the electron acceptor to transport and separate electrons. Deposited CdS quantum dots obtained by successive ionic layer adsorption reaction can effectively absorb visible light and thus act as a light absorber. The TiN/C3N4/CdS nanotube arrays core/shell structure could be verified by X-ray diffractions, Raman spectra, scanning electron microscopy, transmission electron microscopy, energy dispersive spectroscopy elemental mappings and X-ray photoelectron spectroscopy. Compared with TiN/C3N4 nanotube arrays, the TiN/C3N4/CdS samples greatly improve the photoelectrochemical performance, which can be evaluated by photoelectrochemical tests and photoelectrochemical catalytic degradation. Especially, the optimized photocurrent density of TiN/C3N4/CdS has almost 120 times improvement on TiN/C3N4 at 0 V bias under simulated sunlight, which can be ascribed to the effective expansion of the light absorption range and separation of electron-hole pairs.

摘要：为了提高接收天线系统的增益以及灵敏度,对于天线与射频前端组成的接收系统采用了一种有源集成接收天线的设计方案,从而省略了传统设计中的有源电路与微带天线之间的匹配网络.依照此方案,设计并实现了一个背馈结构的矩形微带天线与前级低噪声放大器电路的有源集成.矩形微带天线的馈电点与低噪声放大器的输入端通过金属探针相连,当天线在2.48 GHz谐振时,通过选择合适的馈电点位置,天线产生放大器设计所需的输入阻抗.有源集成背馈式接收天线工作于S波段,最终的测试结果显示了其优良的特性.

摘要：核电站靠海水库修建的出水口构筑物,其结构尺寸受场地限制且需同时考虑地震及高潮位影响,抗震设防要求高,可供采取的措施有限,因此需对结构的形式、尺寸进行特别的考虑,充分挖掘现有结构的抗震潜力。本文结合实际工程,在满足结构尺寸要求的条件下对结构进行抗震设计分析,通过工程实施的验证,得到的结果完全能满足结构功能要求,并可对类似工程的设计与施工提出指导。

摘要：为了克服传统DTI可视化技术存在计算空间大、信息丢失等问题,提出一种基于Perfect Spatial Hashing稀疏数据压缩方法的高分辨率DTI纤维丛可视化方法.将流场可视化中的streamball表示改进为沿着积分曲线布局的可参数化混合元球体,并将这种参数化混合元球体表示规范为一个高分辨率的稀疏三维密度场;进而采用Perfect Spatial Hashing稀疏数据压缩方法压缩该密度场,在保持数据高精度的同时提供了数据的高效随机访问特性.实验结果表明,采用文中方法得到的可视化结果不仅能清晰地揭示组织结构的连通性,还能展示局部张量细节信息.用户只需简单地改变等值面参数就可实时观察可视化结果.

摘要：随着电子设计自动化(EDA)和计算机技术的发展,用软件手段实现硬件设计已成为电子设计领域的迫切需要,笔者在电子设计实践教学中运用软件工程方法,引入了现代EDA技术,结合设计实例分析探讨了其在实践教学中的优越性,旨在提高本科学生的创新能力,培养电子类宽口径复合型人才。

摘要：为实现三维不规则体数据场的高效绘制,提出一种适用于GPU的四面体体数据规则化和可视化算法.将以四面体为基本单元的稀疏体数据用一个有限深度的八叉树结构逼近,并将逼近误差表达为一个离散的完全空间哈希结构;然后将半规则的八叉树转换为规则的八叉树纹理(三维),并将完全空间哈希表转换为三维查找表,两者均可在绘制时快速随机取值,故可直接作为三维纹理在GPU中访问.通过这种双规则化的表示方法,可将四面体体数据的可视化转化为在GPU中并行地绘制2种三维纹理.实验结果表明,该算法在处理空间稀疏体数据时保证了较高的精度,同时减少了数据存储量.

摘要：针对江苏宿迁中等专业学校学生学习C语言存在教学资源、网络学习资源整合需求,为学生提供课余C语言学习与交流平台,提出开发基于Apache+PHP+My SQL框架的C语言在线学习系统。根据教师和学生需求介绍了该系统模块设计与数据库设计,并着重阐述了该系统实现的几个关键技术。开发和运行实践结果表明,这些技术在WEB开发中具有一定的通用性,简单而又实用,具有实践意义。

摘要：充分利用多种实用性工程软件,开发适合不同学生需求的柔性课设系统,根据学生知识体系和需求进行方案配制,使课程设计更具有灵活性,并从广度和深度上提高了学生的实践知识和设计水平。

摘要：阐述了城市宏观交通组织对解决城市交通问题的意义,在此基础上,从道路可接受服务水平、交通组织措施优选和拥堵范围3个角度分析了城市宏观交通组织方案的设计思路,给出了较完整的交通组织方案设计流程,并将其模拟应用于重庆朝天门地区交通组织方案优化。