【电学】用硒，碲制成的干片整流器，焊层的汽相淀积

dry-plate rectifier from selenium, tellurium, pressing on the layer

dry-plate rectifier from selenium, tellurium, surface treatment of the layer

selenium layer dry-plate rectifier

melting on dry-plate rectifier from selenium, tellurium, melting on the layer

dry-plate rectifier selenium, tellurium

dry-plate rectifier

dry-plate rectifier from selenium, tellurium

of dry-plate rectifier from selenium, tellurium