n*****1
发帖数: 1329 | 1 On May 21, 1946, with seven other colleagues watching, Slotin performed an
experiment that involved the creation of one of the first steps of a fission
reaction by placing two half-spheres of beryllium (a neutron reflector)
around a plutonium core. The experiment used the same 6.2-kilogram (13.7 lb)
plutonium core that had irradiated Harry K. Daghlian, Jr., later called the
"Demon core" for its role in the two accidents. Slotin grasped the upper
beryllium hemisphere with his left hand through a ... 阅读全帖 |
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发帖数: 1 | 2 ITEM Quantity Cost in Dollars
ATOMIC MATERIALS
Beryllium metals 9,681 lbs. $ 10,874.
Cadmium alloys 72,535 lbs. 70,029.
Cadmium metals 834,989 lbs. 781,466.
Cobalt ore & concentrate 33,600 lbs. 49,782.
Cobalt metal & Cobalt bearing scrap 806,941 lbs. 1,190,774.
Uranium metal 2.2 lbs. ---
Aluminun tubes (for rea... 阅读全帖 |
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p*******y
发帖数: 63 | 4 16 Curie: Americium 241-Beryllium, 这个很猛吗？
1.7 Curie: Cesium 137 |
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a****1
发帖数: 654 | 5 Report: 'Dirty bomb' parts found in slain man's home
By Walter Griffin
Posted Feb. 10, 2009, at 10:22 p.m.
BELFAST, Maine — James G. Cummings, who police say was shot to death by his
wife two months ago, allegedly had a cache of radioactive materials in his
home suitable for building a “dirty bomb.”
According to an FBI field intelligence report from the Washington Regional
Threat and Analysis Center posted online by WikiLeaks, an organization that
posts leaked documents, an investigation into th... 阅读全帖 |
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i******r
发帖数: 1175 | 6 鱉完成的這量子計算模擬落後有10年了吧。量子計算領先梯隊裏沒有中國團隊。沒有一
樣重要研究成果是中國人的。
Timeline[edit]
Main article: Timeline of quantum computing
In 1959 Richard Feynman in his lecture "There's Plenty of Room at the Bottom
" states the possibility of using quantum effects for computation.
In 1980 Paul Benioff described quantum mechanical Hamiltonian models of
computers[57] and the Russian mathematician Yuri Manin motivated the
development of quantum computers.[58]
In 1981, at a conference co-organized by MIT and IBM, physicist ... 阅读全帖 |
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j**********g
发帖数: 8 | 7 本人女生，力量不是很大，个字不是很高，算介于初级和中级之间的水平。
想买个牌子，100以内吧，尽量80以内。
在考虑这几个：
ProKennex TriFlex 6666 Badminton Racket
Victor Beryllium 3500 Badminton Racket
Head Airflow 5 Badminton Racket
Yonex MP45
最后问个弱弱的问题，87g和80g区别大么？ Head拍子好么？
多谢了~~ 我已经查了一下午了...崩溃边缘 |
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c**i
发帖数: 6973 | 8 Whitney Vargas, The Sublime Cats of Cartier; Uncovering the artistry behind
the legendary French house's iconic panther. Wall Street Journal Magazine,
Aug 27, 2011
http://online.wsj.com/article/SB10001424053
111903918104576500663156138544.html
Note:
(a) Cartier SA
http://en.wikipedia.org/wiki/Cartier_SA
(Cartier was founded in Paris in 1847 by Louis-François Cartier)
Frech surnames Cartier or Chartier (from Old French charette cart) has
English counterpart: Carter.
(b) The French surname ... 阅读全帖 |
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H********g
发帖数: 43926 | 9 10e-18 埃托秒
1 attosecond: the time it takes for light to travel the length of three
hydrogen atoms
12 attoseconds: record for shortest time interval measured as of 12 May 2010
[5]
24 attoseconds: the atomic unit of time
67 attoseconds: the shortest pulses of laser light yet created[6]原来现在有
这么短的脉冲啊
100 attoseconds: fastest ever view of molecular motion[7]
200 attoseconds (approximately): half-life of beryllium-8, maximum time
available for the triple-alpha process for the synthesis of carbon and
h... 阅读全帖 |
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d********O
发帖数: 1196 | 10 Title: Hydration of Zinc Ions: A Comparison with Magnesium and Beryllium
Ions
J. Am. Chem. Soc., 1995, 117 (13), pp 3754–3765
DOI: 10.1021/ja00118a012
Please send to D********[email protected], if it is more convenient for you.
Thank you very much! |
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o*****o
发帖数: 113 | 12 Article Title:
Photodetachment of some diatomic negative hydride ions beryllium
monohydride(-), magnesium monohydride(-), calcium monohydride(-), zinc
monohydride(-), phosphorus monohydride(-), arsenic monohydride(-)
Author:
Rackwitz, R
Journal Title:
Zeitschrift fuer Naturforschung, Teil A: Astrophysik, Physik und
Physikalische Chemie
ISSN:
0044-3166
Published:
1977 Volume: 32A Issue: 6
could you send it to i*****************[email protected]
thank you! |
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s***e
发帖数: 5242 | 13 by Freeman Dyson
12/2010
In 1946 Subrahmanyan Chandrasekhar gave a talk at the University of Chicago
entitled “The Scientist.” 1 He was then 35 years old, less than halfway
through his life and less than a third of the way through his career as a
scientist, but already he wa reflecting deeply on the meaning and purpose of
his work. His talk was one of a series of public lectures organized by
Robert Hutchins, then the chancellor of the university. The list of speakers
is impressive, and included ... 阅读全帖 |
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M*********e
发帖数: 3153 | 15
MHW的号码系统比较怪，
这款，我得穿S号
但是XENON我得穿M号 |
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