（1）主题：Eletrically and optically controlled charge transfer at graphene interface
Due to the unique electrical and optical properties, graphene is a promising material in the fields of integrated circuit, gas sensor and optoelectronic devices. The finite density of state near the Dirac point makes the Fermi level of graphene sensitive to the external electric field and chemical environment. In turn, the Fermi level plays an important role on the charge transfer process between graphene and environment, including adsorbed molecules and surface state of substrate. In this talk, we systematically studied the charge transfer properties and mechanism by electrically tuning the Fermi level of graphene and optically inspiring electrons over the barrier between graphene and environment. The results demonstrated here are of great importance to promote various applications of graphene, such as gas sensing, photodetector and new memory device.
Dr. Cao received the bachelor degree of Materials Science and Engineering from Chang’an University in 2013 and Ph.D. degree of Electronic Science and Technology from Xi’an Jiaotong University in 2018, respectively. He currently works as a Postdoctoral Fellow in the School of Optoelectronic Science and Engineering of UESTC. Dr. Cao is working in the field of two-dimensional materials and device. His main research interests include 2D-materials based transistors, optoelectronics as well as their potential applications in sensors and synaptic electronics.
（1）主题：Safety Analysis of Safety-Critical Software of High-Speed Railway Signaling System
By the end of 2018, China's high-speed railway line mileage has hit 29,000 kilometers, topping the global chart. In China’s railway signaling system, the software whose failure may cause heavy losses such as casualties is known as safety-critical software and is designed to be SIL4 certified. In this talk, we briefly discuss the safety analysis methods of railway signaling safety-critical software. There are three issues: (1) the characteristics of railway signaling safety-critical software; (2) the lifecycle, development model and safety requirements of these software; (3) the safety analysis method, including formal modeling method of RTSC and model-based testing method.
LI Yao received the Ph.D. degree from the Southwest Jiaotong University in 2018, and currently works as a Postdoctoral Fellow in the school of optoelectronic science and engineering of UESTC. Dr. Li is working in the field of railway signaling safety-critical software safety analysis. His research focus on the formal modeling method and model-based testing method for the railway signaling system, and the main work has been applied in 3 projects of China Railway Corporation.
编辑：卫道鸿 / 审核：王晓刚 / 发布者：陈伟