Ambient flash sintering of reduced graphene oxide/zirconia composites:Role of reduced graphene oxide

Fabrication of graphene/ceramic composites commonly requires a high-temperature sintering step with long times as well as a vacuum or inert atmosphere,which not only results in property degradation but also significant equipment complexity and manufacturing costs.In this work,the ambient flash sintering behavior of reduced graphene oxide/3 mol% yttria-stabilized ZrO₂(rGO/3 YSZ) composites utilizing rGO as both a composite component and a conductive additive is reported.When the sintering condition is carefully optimized,a dense and conductive composite can be achieved at room temperature and in the air within 20 s.The role of the rGO in the FS of the rGO/3 YSZ composites is elucidated,especially with the assistance of a separate investigation on the thermal runaway behavior of the rGO.The work suggests a promising fabrication route for rGO/ceramic composites where the vacuum and furnace are not needed,which is of interest in terms of simplifying the fabrication equipment for energy and cost savings.     

天线间耦合度自动测试系统设计

多天线系统的电磁兼容性很大程度上取决于系统内收发天线间的射频能量耦合。天线间耦合度是评估系统级电磁兼容性的重要指标。针对目前传统手工测试的种种弊端,设计了基于射频开关自动切换的天线间耦合度自动测试系统,详细阐述了系统硬件构成、软件的设计思路以及具体的测试流程,使用LabVIEW编写软件控制收发天线对的自动切换,实现自动测量,具有测量误差小,测量便捷等优点。     

政府在落实高校办学自主权中的作用刍议

高校办学离不开政府的管理,政府在落实高校办学自主权中发挥着重要的作用。目前,政府对高校的管理内容过细、方式过于直接。政府应通过法律、经济、计划、行政、信息等手段对高校自主办学进行宏观的、间接的、服务型的管理。     

结肠镜检查者肠道准备无效的原因分析及应对措施

目的:探讨结肠镜检查者肠道准备无效的原因及应对措施.方法:有经验的肠镜检查医师根据肠道清洁效果评价指标进行评价.结果:1313例检查者中有49例肠道准备无效.结论:服药方法、疾病因素、年龄、心理状态、肠镜检查次数等都对肠道准备效果产生了影响.     

临淮岗洪水控制工程管理通过水利部考核的做法

本文简要阐述临淮岗工程水闸处在创建水利部验收水管单位过程中做法,在此基础上总结成功申报经验,供有关单位参考.     

Degenerate problems of optimal control. II

The paper is the second part of the review of the results obtained by the special theory of the degenerate problems of optimal control and its applications, including the newest ones. Consideration was given to the methods based on the rearrangement of the degenerate problems in the smaller-order regular derivative problems, the main types of solutions of the derivative problems, and the issues of their realization as the generalized solutions of the original problems. The generalized conditions for their optimality were derived. Examples, both methodological and applied, were presented to demonstrate the efficiency of these methods.     

硅烷改性聚合物密封剂的研究进展

详细阐述了硅烷改性预聚体的合成方法和硅烷改性聚合物密封剂的制备及固化机理,总结了国内外硅烷改性聚合物密封剂的研究现状及进展,最后分析了硅烷改性聚合物密封剂在我国工业发展中的重要作用。     

A Simple Method for the Growth of Very Smooth and Ultra-Thin GaSb Films on GaAs (111) Substrate by MOCVD

We present a simple thermal treatment with the antimony source for the metal–organic chemical vapor deposition of thin GaSb films on GaAs (111) substrates for the first time. The properties of the as-grown GaSb films are systematically analyzed by scanning electron microscopy, atomic force microscopy, x-ray diffraction, photo-luminescence (PL) and Hall measurement. It is found that the as-grown GaSb films by the proposed method can be as thin as 35 nm and have a very smooth surface with the root mean square roughness as small as 0.777 nm. Meanwhile, the grown GaSb films also have high crystalline quality, of which the full width at half maximum of the rocking-curve is as small as 218 arcsec. Moreover, the good optical quality of the GaSb films has been demonstrated by the low-temperature PL. This work provides a simple and feasible buffer-free strategy for the growth of high-quality GaSb films directly on GaAs substrates and the strategy may also be applicable to the growth on other substrates and the hetero-growth of other materials.     

Recent Progress on the Development of Magnetically-Responsive Micropillars: Actuation,Fabrication, and Applications

Stimuli-responsive micro-pillared structures can perform complex and precise tasks at the microscale through dynamic and reversible deformation of the pillars in response to external triggers. Magnetic field is one of the most common actuation strategies due to its incomparable advantages such as instantaneous response, remote and nondestructive control, and superior biocompatibility. Over the past decade, many researches are attempted to design and optimize magnetically-responsive micropillars for a wide range of applications and great progresses are accomplished. In this review, the most important aspects of recent progress of magnetically-responsive micropillars are covered to give a comprehensive and systematical introduction to this new field, from the actuation mechanisms, fabrication methods, and deformation patterns to the practical applications. The increasingly maturing fabrication techniques can provide low-cost and large-scale magnetic micropillars with homogeneous responses. Some advanced techniques are developed to fabricate micropillars with programmable and reprogrammable responses for site-specific and reconfigurable actuations. On the other hand, practical applications for particle/droplet/light manipulation, flow generation, miniature swimming/climbing/carrying microrobots, tunable adhesion, cellular probe, fog collector, and anti-ice surfaces are also summarized. Finally, current challenges that limit the industrial implementation are discussed and the authors’ perspectives on the future directions of magnetically-responsive micropillars are stated.     

各向异性海洋湍流对外差式DPSK无线光通信系统的性能研究

应用广义的惠更斯-菲涅耳原理及改进的Rytov方法,采用基于Gamma-Gamma光强概率分布的海洋湍流信道模型,得到了中断概率解析式.并在此基础上对各向异性海洋湍流高斯光束外差式差分相移键控(DPSK)调制的中断概率性能进行了研究.仿真分析了不同的各向异性海洋湍流下各种海洋湍流参数(温度与盐度波动对功率谱变化贡献之比...