信号 : 484 phrases in 19 subjects |
Antennas and waveguides | 3 |
Electricity generation | 2 |
Electronics | 12 |
General | 15 |
Lighting other than cinema | 3 |
Magnetics | 3 |
Microsoft | 89 |
Power lines | 28 |
Radio | 110 |
Radiobiology | 1 |
Rail transport | 59 |
Semiconductors | 2 |
Sound recording | 2 |
Telecommunications | 60 |
Telegraphy | 82 |
Telephony | 6 |
Thermal Energy | 1 |
Vacuum tubes | 2 |
Video recording | 4 |