文章对Go Ahead Web Server的基本特点和运行环境进行了介绍,结合嵌入式远程监控系统的现状,将嵌入式开发平台、Linux操作系统、Go Ahead Web Server和I n t e r n e t融合在一起,设计了一个控制电压转换的嵌入式远程监控系统。应用结果表明,Go Ahead Web Server反应迅速,可靠稳定,在实际应用中具有可行性,对嵌入式产品的管理和控制可以得到满意的效果。 相似文献
Co3?xMnxO4 is a bimetal oxide with excellent electrochemical activity in alkaline solution, has been regarded as a promising alternative in the field of ion-air batteries and proton exchange membrane fuel cell (PEMFC). Herein, we report a simple solvothermal-calcination method to fabricate Co3?xMnxO4 with tunable external Co3+/Co2+ and Mn3+/Mn2+ ratio. The tunable ratio of element valence in the bimetal results in a higher exposure of active center for oxygen redox reaction (ORR), and thus lead to a better ORR activity, which was confirmed by X-ray photoelectron spectroscopy characterizations and electrochemical measurements. Specially, Co1.8Mn1.2O4 with a Co3+/Co2+ ratio of 2.08 showed an overpotential of 0.37 V at benchmark ORR current density of 3 mA/cm2 in 0.1 M KOH, which is lower than that of pure oxide (Mn3O4 0.53 V and Co3O4 0.56 V). In addition, the as prepared Co1.8Mn1.2O4 exhibited a positive half-wave potential (0.83 V vs RHE) due to their more active sites, promotes charge transfer, adsorption and desorption of oxygen species. This work provides a strategy for the design and fabrication of earth-abundant, low-cost electrocatalysts for PEMFC in practical applications.
Graphic Abstract
Co3?xMnxO4 was fabricated by tuning external Co3+/Co2+ and Mn3+/Mn2+ ratio, and the activity initially shows a positive correlation with the ration of Co3+/Co2+ in Co3?xMnxO4.