气体氮化

冲裁模材料常用的热处理为何？渗氮法？真空渗氮法？之后须回火吗？几次？

sweep gas

residue gas

obtaining SYNTHESIS gas from solid carbonaceous materials

gas-liquid chromatography, GLC

rich gas

natural gas odorant

feed-water preheating with exhaust steam and gas

preparative gas chromatograph