The technology of exhaust gas recirculation (EGR) has been researched in a turbocharged direct-injected diesel engine in order to reduce Nitrogen Oxides (NOX) emission.

针对增压直喷柴油机，开展了应用废气再循环（EGR）技术降低氮氧化物（NOx）排放的研究。

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Also, to comply with prevailing U.S. emissions standards on nitrogen oxides, or NOx, these big diesels require fairly complicated systems of postcombustion treatment with a water-based urea solution, called AdBlue.

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