And the heavier oxygen from a natural process that left more of the light isotope in the part of the nebula that made the sun.

重量较大的氧来自某种自然过程，在此过程中，大部分的轻同位素留在了形成太阳的部分星云中。

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Scientists say the excess heavy nitrogen could have come from a comet. And the heavier oxygen from a natural process that left more of the light isotope in the part of the nebula that made the sun.

科学家认为重氮来自一颗彗星，而重氧则是来自行星形成的自然过程，这一过程把更轻的氧同位素留在了星云中，形成了太阳。

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It contains a tiny pellet of fuel made from an isotope of hydrogen called deuterium.

其中放置了一个更微小的氘(氢的一种同位素)燃料丸。

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The isotope, known as a medical tracer, is made outside the United States by a complicated process requiring highly enriched uranium from nuclear reactors.

NEWYORKER: Fussbudget

This isotope, with a half-life of 2.6 million years, is not made in significant quantities by any process on Earth, but is expelled by supernovae.

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They've made the allegation, certainly, both to the New York Times and in paperwork provided, that the carbon isotope test was positive, but they don't provide the documents that show that.

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