A combined solar chimney is proposed in this paper that integrates an inclined-roof solar chimney with a traditional Trombe wall. The ventilation performance of the combined solar chimney is analyzed numerically and then compared with the Trombe wall and the inclined-roof solar chimney. The feasibility of different operation modes and the ventilation effect under different environment conditions are also discussed. The results show that when the ambient temperature ranges from 298 to 303 K in the summer, a natural ventilation mode is appropriate. Otherwise, an anti-overheating mode is recommended. When the ambient temperature is lower than 273 K in the winter, a space heating mode has a better heating effect. A preheating mode can be employed to improve the indoor air quality when the ambient temperature is higher than 278 K. The simulation results indicates that the ventilation effect of the combined solar chimney is better than that of the Trombe wall and the inclined-roof solar chimney, and the problem of overheating can be avoided. The study provides guidance for the optimal operation of a combined solar chimney.

The 500kV Yangdong Line II starts at Shanxi Yangcheng Power Plant and ends at Shandong Dongming Switch Station. It was completed and put into operation in May 2000, with a total length of 246.465 km. In this paper, through the field investigation and weather operation statistics, as well as the metal micro-analysis of the broken strand OPGW sample, it is concluded that the root cause of the broken strand is that the continuous current discharge process of the lightning channel can keep the arc root for a long time, which may cause ablation on the surface and even the inside of the single stranded wire. This paper also put forward measures to prevent such failures.

Testing methodologies integrating wedge-loaded double cantilever beam (WDCB) methods with digital image correlation (DIC) are promising for measuring the Mode I interlaminar fracture toughness of fiber-reinforced composites owing to the ability to bypass