非线性干涉滤光片开关特性及逻辑功能

应用干涉滤光片作为一种光学双稳器件,演示了光学逻辑开关功能。     

WLAN网管系统的现状和发展

2001年以来，全球WLAN（无线局域网）市场应用的瓶颈被打破，中国也迎来了WLAN商业化运作和服务的春天，WLAN为我们带来了一种全新的、灵活的工作方式，同时也带来了新的挑战，本文将对WLAN网络管理的主要内容和具体指标进行阐述，并对各大厂商的WLAN网管产品进行简单介绍和比较。     

Stable social foraging swarms in a noisy environment

Bacteria, bees, and birds often work together in groups to find food. A group of robots can be designed to coordinate their activities to search for and collect objects. Networked cooperative uninhabited autonomous vehicles are being developed for commercial and military applications. Suppose that we refer to all such groups of entities as "social foraging swarms". In order for such multiagent systems to succeed it is often critical that they can both maintain cohesive behaviors and appropriately respond to environmental stimuli (e.g., by optimizing the acquisition of nutrients in foraging for food). In this paper, we characterize swarm cohesiveness as a stability property and use a Lyapunov approach to develop conditions under which local agent actions will lead to cohesive foraging even in the presence of "noise" characterized by uncertainty on sensing other agent's position and velocity, and in sensing nutrients that each agent is foraging for. The results quantify earlier claims that social foraging is in a certain sense superior to individual foraging when noise is present, and provide clear connections between local agent-agent interactions and emergent group behavior. Moreover, the simulations show that very complicated but orderly group behaviors, reminiscent of those seen in biology, emerge in the presence of noise.     

多媒体课件改变了教师的“主讲”地位

随着高等教育教学改革步伐和数字化教学的不断推进和发展,越来越多的教师热衷于多媒体教学课件的使用和研究,传统的教学模式被逐渐取代,教师教学的主导地位越来越不明显,数字教学的时代悄然而至。     

基于关联分析的变电站附属设备差异化运维

针对变电站附属设施缺陷分析手段欠缺、运维策略粗放、简单周期化的问题,研究基于关联分析的变电站附属设备差异化运维技术,基于现有的变电站附属设备管理系统搜集的缺陷历史数据,从变电站、附属设备类型、厂家、型号和投运年限、季节等维度对变电站附属设备进行关联分析,实现附属设备的状态评估,提出附属设备差异化运维方案,从而提升运维人员决策的预见性和全局性.     

PAN/FPU Composite Nanofiber Membrane with Superhydrophobic and Superoleophobic Surface as a Filter Element for High-Efficiency Protective Masks

Recently, because of the outbreak of COVID-19, the demand for various types of filter elements in protective materials has increased globally. Furthermore, new requirements for the filtration performance of PM2.5 liquid (oil) particles have been put forward. In this work, Superhydrophobic and superoleophobic composite nanofibers with excellent filtration capacity for oil and salt particles are developed through the modification of polyacrylonitrile (PAN) by fluoro-polyurethane (FPU) doping. The results show that the PAN/FPU composite nanofibers doped with 9 wt% FPU has a uniform fiber morphology with a diameter of 240 ± 30 nm. Compared to the pure PAN nanofibers, the water-based contact angle of PAN/FPU increases from 90 ± 5° to 151 ± 5°, and the oil-based contact angle increases from 58 ± 2° to 152 ± 3°. Importantly, at a high flow rate of 95 L min⁻¹, the filtration efficiency of the PAN/FPU nanofiber membrane for 0.3 µm oil particles increases from 92 ± 1% to 99.2 ± 0.1%. After cyclic loading, the filtration efficiency of 0.3 µm oil particles remains above 98%. Meanwhile, the filtration efficiency for 0.3 µm salt particles remains at 98.23 ± 0.1%. The PAN/FPU nanofiber membrane developed in this work is effective in applications and has good market prospects as a protective filtration material.     

Study on sintering process and characteristic of nanosized soft magnetic MnZn ferrite powders

The effect of sintering process (especially the sintering temperature) on the magnetic property and microstructure of sintered sample of nanosized soft magnetic MnZn ferrite powder was investigated. The sintered sample of MnZn ferrite was prepared by both traditional pressing and cool isostatic pressing on MnZn ferrite nanoparticals. The sintering process of which was segmented. Thedensity, microstructure and phase composition of sintered sample were analyzed by Archimedes'law, scanning electron microscopy (SEM) and X-ray diffraction (XRD). The grain growth and densification in sintering process of MnZn ferrite were investigated. The magnetic property was measured by vibrating sample magnetometer (VSM) and Nim2000 magnetic material testing system. The results show that the better sintering temperature is 850 ℃, at which the better magnetic property and microstructure of sintered compact were obtained.     

RTM工艺中气泡形成及消除研究

总结了关于RTM（树脂压铸）工艺中气泡缺陷的文献报道，对RTM中气泡缺陷的形成机理、影响因素及各研究者提出的消泡方法、理论和模型进行了概述，同时对RTM工艺中气泡缺陷的研究现状给予充分关注，并对RTM缺陷研究的未来方向进行了展望。     

倾角传感器稳定性测试与分析

为了进一步加强产品质量监管,更加全面地了解倾角传感器的稳定性,随机抽取了两款倾角传感器,针对倾角传感器的启动特性、动态特性和稳态特性进行测试与分析.为了更全面地展示出倾角传感器稳定性,结合倾角传感器在设备上面从启动到稳定工作的整个过程,文章给出较为合理的测试方法和步骤,重点分析了倾角传感器启动时的快速稳定性、动作时的动态跟随性和静态时的稳态特性.测试结果表明,动态特性好的倾角传感器启动时会更快地稳定,而稳态特性相对降低.     

基于云模型与PROMETHEE方法的语言型Z-number多属性决策

针对属性权重未知,属性值为语言型Z-number的多属性决策问题,提出了一种基于云模型与丰富度评估的偏好排序组织方法（Preference ranking organization method for enrichment evaluation, PROMETHEE）的决策方法。首先,引入语言尺度函数,然后利用其建立转化模型完成语言型Z-number向云模型的转化。此外,通过定义云可能度函数,建立属性权重求解公式及构建正弦偏好函数,进而计算方案的优先指数,通过计算方案的正负方向优序级别值得到备选方案综合优序级别值,进而得到方案排序。最后通过算例及比较分析验证本方法的有效性和可行性。