Catalytic converters reduce carbon monoxide, oxides of nitrogen, and volatile organic compounds in emissions and necessitated the use of lead-free fuel.

催化转炉减少了一氧化碳，氧化氮和挥发性有机混合物等的排放，而且无铅燃料的应用也当成为必要。

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Serial colour-glazes were tested in that the colouring materials are common metal-oxides, the basic glaze are lead-free, cadmium-free, zinc-free and low-magnesium frit-glazes.

以普通着色金属氧化物为色剂，基釉为无铅无镉无锌低镁透明熔块釉，研制了系列透明色釉。

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Glaze is mostly translucent, but da Vinci would also slip in small amounts of pigments, such as manganese and lead oxides.

ECONOMIST: The da Vinci method

The researchers examined the prevailing inspection system called On-Board Diagnostics II (OBD-II), which tests for excessive carbon monoxide, hydrocarbons, and nitrogen oxides, and also checks the power-train systems for problems that might eventually lead to elevated emissions levels.

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