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频率脉冲调制 |
frequency pulse modulation : 48 phrases in 13 subjects |
Air defense | 7 |
Automobiles | 1 |
Aviation | 2 |
Earth sciences | 4 |
Electric machinery | 1 |
Electronics | 17 |
Geophysics | 1 |
Information technology | 1 |
Radio | 2 |
Remote sensing | 1 |
Space | 3 |
Technology | 7 |
Telecommunications | 1 |