Group 1 - Silicon nitride (Si3N4) is a covalent compound composed of silicon and nitrogen, exhibiting superior properties such as high-temperature resistance (flexural strength over 350 MPa at 1200°C), acid and alkali corrosion resistance, and self-lubrication, making it widely applicable in aerospace, defense, and machinery sectors [2][10][14] - The market size for silicon nitride powder in China reached 170 million yuan in 2021, with projections to grow to 370 million yuan by 2028, reflecting a compound annual growth rate (CAGR) of 10.40% from 2022 to 2028 [2][10][14] - Domestic high-quality silicon nitride raw materials are scarce, leading to a reliance on imports, primarily from suppliers like Ube Industries and Toshiba [2][16] Group 2 - The chemical new materials sector on the North Exchange experienced a weekly increase of 2.82%, with notable performance in the rubber and plastic products industry, which rose by 8.05% [3][22][23] - The North Exchange 50 index closed at 1441.72 points, reflecting a weekly increase of 1.56%, while the Shanghai and Shenzhen 300 index rose by 1.23% [21][24] - Key stocks in the chemical new materials sector that performed well include Huami New Materials (+33.97%), Guangxin Technology (+23.63%), and Litong Technology (+14.81%) [3][26][29] Group 3 - Huami New Materials reported a revenue of 202.93 million yuan for the first half of 2025, marking a year-on-year increase of 6.49%, while its net profit attributable to shareholders decreased by 18.57% [4][51] - The company continues to focus on special rubber and plastic products, increasing its R&D investment and adding 10 new patents during the period [4][52] - The Kaide Quartz multi-channel quartz tube project was included in the list of new technologies and products in Beijing, indicating recognition of innovation [4][52]