常用电子元器件参考资料，包括电阻器、电容器、电感器和变压器、半导体管等，和常用电子元器件型号命名法及主要技术参数-Commonly used reference materials for electronic components, including resistors, capacitors, inductors and transformers, semiconductors, tubes, etc., and models of electronic components commonly used nomenclature and main technical parameters