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【Objective】Focusing on the strategic goal of building an internationally leading energy Internet enterprise with Chinese characteristics, in accordance with the promotion of the deep integration and application of advanced information and communication technologies and advanced energy technologies, and focusing on the overall requirements of improving the power communication network to support and guarantee the safe operation of the power grid, Suzhou Electric Power launched the construction of a 220 kV protection private communication network since 2019. There exist problems with the 220 kV relay protection channel in Suzhou, such as long repair time, high occupancy of communication cabinet resources, and mixed networking of protection and communication services, which pose hidden dangers to the safe operation of the power grid.【Methods】This paper analyzes the current status and existing problems of Suzhou 220 kV relay protection channel. Combined with the actual situation of optical communication network in Suzhou, this paper proposes using 2 Mbit/s optical interface to directly connect protection equipment for carrying the relay protection channel of B port, and refines the power transformation plan, networking mode, protection business bearing mode, and network management bearing mode.【Results】Utilizing the respective characteristics of the direct channels with fiber optic and the multiplexing channels with protection private communication network, Suzhou Electric Power has built a protection private communication network which covers all transformer substations owning 220 kV outlets by customizing the small private communication transmission equipment that matches relay protection services.【Conclusion】The protection private communication network accessing to the centralized transmission equipment network management could monitor relay protection channels and achieve the observability and testability of the relay protection channels. It has advantages such as rapid failure positioning, failure isolation, and channel detour and comprehensively improves the reliability, independence, flexibility, and operation convenience of the relay protection channels. The protection private communication network has achieved significant application results and innovative results, which is also a beneficial exploration for the application of " 3 routes" for the protect channels.

Online discussions have become important educational activities through which collaborative learning and knowledge construction can be facilitated. This study explores the use of two online discussion tools, online discussion board and VoiceThread, for supporting online course discussion activities among a group of graduate students and investigates the differences in the levels of social presence and social knowledge construction in the two discussion settings. Meanwhile, the participants' posting behaviors and interaction patterns were also examined. Results reveal that the participants contributed more words when using the audio and video features of VoiceThread. Additionally, the graduate students tended to create more contents and demonstrated more social presence behaviors when interacting with others in the VoiceThread discussion platform. However, the participants exhibited fewer social knowledge construction behaviors than they did in the text-based online discussion board.

Kudingcha (Ligustrum robustum (Roxb.) Blume) is widely used as a traditional medicinal and culinary plant of great economic value. It has a long history of use as an ethnic medicine and an alternative to tea in Guizhou, Yunnan and Sichuan provinces of China, and has attracted much attention in recent years. The chemical composition of kudingcha (Ligustrum robustum (Roxb.) Blume) is complex, from which phenylpropanoids, phenylethanoids, monoterpenes, iridoids, flavonoids and volatile oils have been isolated. It has a wide range of pharmacological effects, including lipid-lowering, antioxidant, antiviral, antibacterial, anti-inflammatory, immune regulatory and anticancer activities. However, in recent years, there are few systematic reviews on Ligustrum robustum (Roxb.) Blume, even though it is only mentioned in the reviews on Ligustrum plants or kudingcha, which is not conducive to the standardized research, development and utilization of kudingcha (Ligustrum robustum (Roxb.) Blume). This paper comprehensively summarizes recent research on the composition, pharmacological activity and quality control of kudingcha (Ligustrum robustum (Roxb.) Blume) with focuses on the structural features and pharmacological mechanism of its characteristic components. This paper will provide a theoretical reference for the preparation, separation, structure identification and pharmacological research of the characteristic components of kudingcha (Ligustrum robustum (Roxb.) Blume).