GB/T 21649.1-2024 Chinese PDF (GB/T21649.1-2024) GB 10408-2025 English versions: GB/T 20840

English versions: GB/T 20840

English versions: GB/T 20871

English versions: YY/T 1946-2024

20-2025_Chinese: Methods for chemical analysis of tungsten concentrates - Part 20: Determination of mercury content - Solid sampling and direct mercury analysis method (Chinese: 钨精矿化学分析方法 第20部分：汞含量的测定 固体进样直接测定法)

3-2023_Chinese: Aramid pressboard for electrical purposes - Part 3: Specifications for individual materials (Chinese: 电气用聚芳酰胺纤维纸板 第3部分：单项材料规范)

GB/T 21649.1-2024 Chinese PDF (GB/T21649.1-2024) GB 10408-2025 English versions: GB/T 20840GB T 21649. 1 2024_Chinese: Particle size analysis Image analysis methods Part 1: Static image analysis methods (Chinese: 1) Note Careful: Text of PDF is in Chinese (not English). Delivery (PDF in Chinese): 2 working hours typically, ASAP English versions: GB T 21649. 1 2024