Now radium itself is a constituent of uranium minerals, and two series of experiments by R.J. Strutt and B.B. Boltwood have shown that the content of radium, as measured by the radio-activity of the emanation, is directly proportional to the content of uranium. (Strutt, "Proc. Soc." A, February 1905; Boltwood, "Phil. Mag." April, 1905.) In Boltwood's investigation, some twenty minerals, with amounts of uranium varying from that in a specimen of uraninite with 74.65 per cent., to that in a monazite with 0.30 per cent., gave a ratio of uranium to radium, constant within about one part in ten.英文原著 · 《Darwin and Modern Science》
It was soon discovered that the activity of uranium compounds was proportional to the amount of uranium present in them. Thus radio-activity is an atomic property dependent on the amount of an element and independent of its state of chemical combination.英文原著 · 《Darwin and Modern Science》
Uranium 238.5 alpha > Uranium-X ? 22 days beta, gamma ... Actinium ? no rays > Actinium-X ? 10.2 days alpha (beta, gamma) > Actinium Emanation ? 3.9 seconds alpha > Actinium-A ? 35.7 minutes no rays > Actinium-B ? 2.15 minutes alpha, beta, gamma ...英文原著 · 《Darwin and Modern Science》
In a search for radio-activity in different minerals, M. and Mme Curie found a greater effect in pitch-blende than its contents of uranium warranted, and, led by the radio-active property alone, they succeeded, by a long series of chemical separations, in isolating compounds of a new and intensely radio-active substance which they named radium.英文原著 · 《Darwin and Modern Science》
But the most thorough investigation of a radio-active pedigree is found in Rutherford's classical researches on the successive disintegration products of radium, in order to follow the evidence on which his results are founded, we must describe more fully the process of decay of the activity of a simple radio-active substance. The decay of activity of the body known as uranium-X is shown in a falling curve (Fig. It will be seen that, in each successive 22 days, the activity falls to half the value it possessed at the beginning.英文原著 · 《Darwin and Modern Science》
In a series of analyses of uranium minerals, therefore, we ought to be able to pick out its more short-lived descendants by seeking for instances of such proportionality.英文原著 · 《Darwin and Modern Science》
an atom without a bomb * * A dot without the com * * And I'd probably still live with my mom * * And he'd probably still live with his mom * * Ever since I met you, you turned my world around * * You supported all my dreams and all my hopes * * You're like uranium-235 and I'm uranium-238 * * Almost美剧 · 《The Big Bang Theory》
What you're seeing is probably radiation from the summer I collected uranium tubes by the train tracks.美剧 · 《2 Broke Girls》
- Tusk won't accept the nomination his holdings are at risk. a hostile takeover. what sancorp is. the subsidiaries. refine and ship the uranium, - Come on, Frank. to take into account, a huge financial exposure.美剧 · 《House of Cards》
The idea of TerraPower is that, instead of burning a part of uranium -- The idea of TerraPower is that, instead of burning a part of uranium --演讲 · 《Innovating to zero! ~ Bill Gates》
The U.S. government confiscated all uranium for use in bomb development. the U.S. government confiscated all uranium for use in bomb development.演讲 · 《Maranto Historys deadliest colors ~ J. V.》