| 词汇 | example_english_berkelium |
| 释义 | Examples of berkeliumThese examples are from corpora and from sources on the web. Any opinions in the examples do not represent the opinion of the Cambridge Dictionary editors or of Cambridge University Press or its licensors. The production resulted in 22 milligrams of berkelium, enough to perform the experiment. From Wikipedia This example is from Wikipedia and may be reused under a CC BY-SA license. The isotope which is the easiest to synthesize is berkelium-249. From Wikipedia This example is from Wikipedia and may be reused under a CC BY-SA license. The production of the second-important isotope berkelium-247 involves the irradiation of the rare isotope curium-244 with high-energy alpha particles. From Wikipedia This example is from Wikipedia and may be reused under a CC BY-SA license. In a thermal reactor, much of it will therefore be converted to berkelium-250 which quickly decays to californium-250. From Wikipedia This example is from Wikipedia and may be reused under a CC BY-SA license. The coordination of the berkelium atom in its trivalent fluoride and chloride is tricapped trigonal prismatic, with a coordination number of 9. From Wikipedia This example is from Wikipedia and may be reused under a CC BY-SA license. He was part of the team that discovered elements 97 and 98 (berkelium and californium) in 1949 and 1950. From Wikipedia This example is from Wikipedia and may be reused under a CC BY-SA license. Since ununseptium has 117 protons in its nucleus and calcium has 20, they thus needed to use berkelium, which has 97 protons in its nucleus. From Wikipedia This example is from Wikipedia and may be reused under a CC BY-SA license. Berkelium is a soft, silvery-white, radioactive metal. From Wikipedia This example is from Wikipedia and may be reused under a CC BY-SA license. Specifically, berkelium-249 has a moderately large neutron capture cross section of 710 barns for thermal neutrons, 1200 barns resonance integral, but very low fission cross section for thermal neutrons. From Wikipedia This example is from Wikipedia and may be reused under a CC BY-SA license. The most difficult steps in the synthesis of berkelium were its separation from the final products and the production of sufficient quantities of americium for the target material. From Wikipedia This example is from Wikipedia and may be reused under a CC BY-SA license. All of the elements with higher atomic numbers, however, have been first discovered in the laboratory, with neptunium, plutonium, americium, curium, berkelium and californium later also discovered in nature. From Wikipedia This example is from Wikipedia and may be reused under a CC BY-SA license. Other elements are named after modern states or cities, with berkelium and californium being named after the city and the state where these elements were discovered. From Wikipedia This example is from Wikipedia and may be reused under a CC BY-SA license. The radioactive decay of uranium produces transient amounts of actinium and protactinium, and atoms of neptunium, americium, curium, berkelium and californium are occasionally produced from transmutation reactions in uranium ores. From Wikipedia This example is from Wikipedia and may be reused under a CC BY-SA license. Similar to the nearly simultaneous discovery of americium (element 95) and curium (element 96) in 1944, the new elements berkelium and californium (element 98) were both produced in 19491950. From Wikipedia This example is from Wikipedia and may be reused under a CC BY-SA license. The remaining 7 transient elements (technetium, promethium, neptunium, americium, curium, berkelium, and californium) occur only rarely, as products of rare nuclear reaction processes involving uranium or other heavy elements. From Wikipedia This example is from Wikipedia and may be reused under a CC BY-SA license. In addition to plutonium, he is credited as a lead discoverer of americium, curium, and berkelium, and as a co-discoverer of californium, einsteinium, fermium, mendelevium, nobelium and seaborgium. From Wikipedia This example is from Wikipedia and may be reused under a CC BY-SA license. The berkelium-249 isotope emits low-energy electrons and thus is relatively safe to handle. From Wikipedia This example is from Wikipedia and may be reused under a CC BY-SA license. The existence of divalent berkelium salts is uncertain and has only been reported in mixed lanthanum chloride-strontium chloride melts. From Wikipedia This example is from Wikipedia and may be reused under a CC BY-SA license. In principle, berkelium-249 can sustain a nuclear chain reaction in a fast breeder reactor. From Wikipedia This example is from Wikipedia and may be reused under a CC BY-SA license. The maximum permissible amount of berkelium-249 in the human skeleton is 0.4 nanograms. From Wikipedia This example is from Wikipedia and may be reused under a CC BY-SA license. Most available berkelium toxicity data originate from research on animals. From Wikipedia This example is from Wikipedia and may be reused under a CC BY-SA license. Difficulty in studying its properties is due to einsteinium-253's conversion to berkelium and then californium at a rate of about 3% per day. From Wikipedia This example is from Wikipedia and may be reused under a CC BY-SA license. Like all actinides, berkelium easily dissolves in various aqueous inorganic acids, liberating gaseous hydrogen and converting into the trivalent oxidation state. From Wikipedia This example is from Wikipedia and may be reused under a CC BY-SA license. Fourteen isotopes of berkelium were identified with mass numbers 238252. From Wikipedia This example is from Wikipedia and may be reused under a CC BY-SA license. A similar behavior is observed for the lanthanide analogue of berkelium, terbium. From Wikipedia This example is from Wikipedia and may be reused under a CC BY-SA license. Nuclear reactors produce mostly, among the berkelium isotopes, berkelium-249. From Wikipedia This example is from Wikipedia and may be reused under a CC BY-SA license. The berkelium was subsequently cooled in 90 days and chemically purified in another 90 days. From Wikipedia This example is from Wikipedia and may be reused under a CC BY-SA license. In experiments during 1949-1950, they produced and identified elements 97 (berkelium) and 98 (californium). From Wikipedia This example is from Wikipedia and may be reused under a CC BY-SA license. Berkelium-249 is a common target nuclide to prepare still heavier transuranic elements and transactinides, such as lawrencium, rutherfordium and bohrium. From Wikipedia This example is from Wikipedia and may be reused under a CC BY-SA license. There is no practical application of berkelium outside of scientific research which is mostly directed at the synthesis of heavier transuranic elements and transactinides. From Wikipedia This example is from Wikipedia and may be reused under a CC BY-SA license. These examples are from corpora and from sources on the web. Any opinions in the examples do not represent the opinion of the Cambridge Dictionary editors or of Cambridge University Press or its licensors. |
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