GB/T 4541-2023 Chinese PDF (GB/T4541-2023) GB 5009.306-2025 2-2025_Chinese: Petroleum and natural gas

2-2025_Chinese: Petroleum and natural gas industries - Materials for use in H2S-containing environments in oil and gas production - Part 2: Cracking-resistant carbon and low alloy steels

GB/T 21413

maintenance and improvement of a GB/T 23331 energy management system (Chinese: 能源管理体系 实施、保持和改进GB/T 23331能源管理体系指南)

GB/T 22453-2025_Chinese: Non-linear optical crystal devices measuring method for laser (Chinese: 激光用非线性光学晶体元件性能测量方法)

GB/T 17263-2025_Chinese: Self-ballasted lamps for general lighting service - Performance specifications (Chinese: 普通照明用自镇流荧光灯 性能规范)

GB/T 4541-2023 Chinese PDF (GB/T4541-2023) GB 5009.306-2025 2-2025_Chinese: Petroleum and natural gasGB T 4541 2023_Chinese: Position indicating lights for life saving appliances of marine (Chinese: ) Note Careful: Text of PDF is in Chinese (not English). Delivery (PDF in Chinese): 2 working hours typically, ASAP English versions: GB T 4541 2023