Papers by Author: Lei Liu

Abstract: The use of a silane coupling agent (3-aminopropyltriethoxysilane) to improve the anticorrosive property of low carbon steel was assessed by DC polarization test and infrared spectroscopy. These tests indicated that the optimal hydrolysis system of γ-APS was available at 25 °C, pH 10, and with 7 vol % APS, 28 vol % absolute ethanol and 65 vol % DI water. Factor of silane volume in hydrolysis systems played an important role in the hydrolysis effect of γ-APS.

Abstract: Watermark technique is one of the technologies of digital product property rights protection. This article from the basic principle, implementation, application, the experimental results were introduced from the aspects such as watermark technology, and analyzes the digital water marking technology based on singular value decomposition.

Abstract: A 220kV substation DC system ground fault detailed analysis and lookup scheme are proposed in this paper. The ground fault was mainly due to the cold weather as well as equipment wiring unreasonable wear the cable jacket rupture, causing 220kV main transformer cooler control box on the 2nd DC grounding occurred. In addition, through this ground fault finding, also found a DC system insulation monitoring device functional shortcomings and DC circuit loop back problems exist, the paper put forward DC circuit loop back detailed solutions, and the insulation monitoring device of the transformation proposal are proposed.

Abstract: Worm cam mechanism is a common indexing mechanism which is widely used in automatic machinery. Because of its high transmission precision requirements, the mechanism has high demands on the cylinder cam. The machining methods of cylinder cam are unique and the methods of special machine tool and NC machining are the two methods that general adopted in the machining of it. In this paper, the method of CNC Programming which is used for machining cylinder cam in 5-axeses high speed DMU 70eVolution Machining Center is introduced. The machining principle of cylinder cam has been studied, and the mathematical model for CNC Programming has also been worked out. The automated compensation of cutting tool’s radius is used in this field for the first time.