Diamond/SiC composites were prepared by vacuum silica vapor-phase infiltration of in situ silicon–carbon reaction, and the thermophysical properties of the composites were modulated by controlling diamond graphitizing. The effects of diamond surface state and vacuum silicon infiltration temperature on diamond graphitization were investigated, and the micromorphology, phase composition, and properties of the composites were observed and characterized. The results show that diamond pretreatment can reduce the probability of graphitizing; when the penetration temperature is greater than 1600 °C, the diamond undergoes a graphitizing phase transition and the micro-morphology presents a lamellar shape. The thermal conductivity, density, and flexural strength of the composites increased and then decreased with the increase of penetration temperature in the experimentally designed range of penetration temperature. The variation of thermal expansion coefficients of composites prepared with different penetration temperatures ranged from 0.8 to 3.0 ppm/K when the temperature was between 50 and 400 °C.

Since the establishment of diplomatic relations between China and South Korea in 1992, the development speed of bilateral economic and trade relations is getting faster and faster, and the quality is getting higher and higher. According to the United Nations Commodity Trade Statistics Database, China became the largest trading partner of South Korea in 2018, while South Korea became the third largest trading partner of China. Under the background of the Belt and Road Initiative, the trade of agricultural products between China and South Korea has become increasingly frequent. This paper discusses the measurement of agricultural trade level between China and South Korea, and analyzes the influencing factors for reference.

The continuous development of international logistics of China and Korea trade have influence, because of the geographical position advantage of the two countries, the trade is very convenient, in this paper, based on the development of international logistics trade of China and Korea are expounded, and put forward the development strategy, including perfecting the infrastructure, strengthen personnel training, strengthening the technical cooperation efficiency, promote bilateral trade contacts.