s********1
发帖数: 581 | 1 请问哪种生物(包括单细胞和多细胞)reproduce by symmetric multiple fission?
请注意multiple fission这里不包括bacteria endospore或者Baeocyte的情形。我特别
需要具体例子，非常着急。
谢谢！ |
|
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s****y
发帖数: 958 | 3 和 Fission SV比较如何？
我今天试了一把SV感觉Fit的很好，保暖也不错，不知道SL怎么样，Local店里没有。 |
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F*Q
发帖数: 3259 | 4 这种情况不是很少，细胞内mitochondira有时候是相当密集的，单独mitochondira 之间的距离很多情况下都在几十个纳米之内。我认为最近几年用这个技术来展示mitochondira fusion/fission 或尤其是mitochondria network 的一些文章，展示的的其实很可能是密集分布的独立的itochondria。 |
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h*******o
发帖数: 4884 | 5 Cannot agree more.
A good cell type for mitochondrial dynamics research is neurons.
Within processes, it is much less chance to get a cluster of mitochondria.
之间的距离很多情况下都在几十个纳米之内。我认为最近几年用这个技术来展示
mitochondira fusion/fission 或尤其是mitochondria network 的一些文章，展示的
的其实很可能是密集分布的独立的itochondria。 |
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p*****m
发帖数: 7030 | 6 用kaede标记mitochondria,UV switch color,然后看两个不同颜色的线粒体融合以后是
不是变成黄的了，是的话说明是fusion,而不是仅仅离得近
类似的也可以用两种颜色标记两种细胞的线粒体，做hybrid cell,看变黄了没有
这样的实验已经发表过不少了吧
之间的距离很多情况下都在几十个纳米之内。我认为最近几年用这个技术来展示
mitochondira fusion/fission 或尤其是mitochondria network 的一些文章，展示的
的其实很可能是密集分布的独立的it |
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h*******o
发帖数: 4884 | 7 电镜不能看live cell image吧
fission and fusion 是需要live cell image的. |
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b**a
发帖数: 47 | 8 有细胞呈球形，但不象链子一样连在一起的吗, 并且用fission方式分裂（无法区分母
细胞和子细胞）？
能否请给出几个例子？ |
|
b**a
发帖数: 47 | 9 有细胞呈球形，但不象链子一样连在一起的吗, 并且用fission方式分裂（无法区分母
细胞和子细胞）？
能否请给出几个例子？ |
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l**a
发帖数: 6415 | 10 删掉一些了。
链接如下
plainenglishnuclear.blogspot.com
.......
1. I live on the West Coast. Am I in danger?
No. Absolutely not.
You won’t even notice except that everyone will keep talking about it for
ages, and it’ll take us even longer to get off coal and oil and natural gas
because people will be afraid of nuclear power again. Go outside, get some
sunshine (or rain, depending), be grateful for the fact that your city isn
’t completely destroyed in an earthquake or a tsunami, hug your loved ones... 阅读全帖 |
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l**t
发帖数: 6971 | 11 http://www.bloomberg.com/news/2011-11-01/tepco-says-nuclear-fis
Possible Nuclear Fission Detected at Fukushima Plant
Tokyo Electric Power Co. detected signs of nuclear fission at its crippled
Fukushima atomic power plant in northern Japan, raising the risk of more
radiation leaks. The situation is under control, officials said.
The company, known as Tepco, began spraying boric acid on the No. 2 reactor
at 2:48 a.m. Japan time to prevent accidental chain reactions. Tepco said it
may have found xe... 阅读全帖 |
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l**t
发帖数: 6971 | 12 http://www.bloomberg.com/news/2011-11-01/tepco-says-nuclear-fis
Possible Nuclear Fission Detected at Fukushima Plant
Tokyo Electric Power Co. detected signs of nuclear fission at its crippled
Fukushima atomic power plant in northern Japan, raising the risk of more
radiation leaks. The situation is under control, officials said.
The company, known as Tepco, began spraying boric acid on the No. 2 reactor
at 2:48 a.m. Japan time to prevent accidental chain reactions. Tepco said it
may have found xe... 阅读全帖 |
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x****u
发帖数: 44466 | 13 文章里面说得很清楚：
decay是指highly radioactive fission products，也就是U什么的分裂之后生成的核
素。
Principles
In a nuclear reactor, the fission of heavy atoms such as isotopes of uranium
and plutonium results in the formation of highly radioactive fission
products. These fission products radioactively decay at a rate determined by
the amount and the type of radioactive nuclides present. Some radioactive
atoms will decay while the reactor is operating and the energy released by
their decay will be removed from the core al... 阅读全帖 |
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m*****a
发帖数: 92 | 14 Japan Nuclear Crisis: What Is a Full Meltdown?
Tuesday March 15, 2011 2:50 PM - Leave a Comment
Japan is on the brink of a nuclear disaster in the wake of its
devastating earthquake and tsunami, with a third explosion at the
Fukushima Daiichi nuclear power station damaging the steel containment
structure of one reactor, and a fire at another spewing radioactive
material into the air. Before the latest explosion and fire, as workers
raced to stay ahead of a full meltdown, The Daily Beast spoke wi... 阅读全帖 |
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t***h
发帖数: 5601 | 15 http://www.ctbto.org/the-treaty/developments-after-1996/2013-dp
Media questions and answers on radionuclide detection
Vienna, 23 April 2013
1. How come the detection was made so late (when you said on 12 March that
it was improbable)?
A: The main detection was made on 8 and 9 April, a smaller one from 12 to 14
April. Detection of radioactive noble gas more than 7 weeks after an event
is indeed unusual, we did not expect this and it did not happen in 2009. We
do not know what has happened at the ... 阅读全帖 |
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s******8
发帖数: 7105 | 16
无知者无畏， 哈哈
==================================================================
Test No. 6 is the codename for the China's first test of a three-staged
thermonuclear device and, also its sixth nuclear weapons test. The device
was detonated at Lop Nur Test Base, or often dubbed as Lop Nur Nuclear
Weapon Test Base, in Malan, Xinjiang, on 17 June 1967. With successful
testing of this three-stage thermonuclear device, China became the fourth
country to have successfully developed a thermonuclear weapo... 阅读全帖 |
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d*b
发帖数: 21830 | 17 没插入减速棒，fission是100%，你插入减速棒后，fission是7%，即使你抽走fuel rod
, 这样的spending rod跟new rod不一样，因为spending rod还有fission,还能产生中
子，所以还有余热。
核工程上一般认为这个过程是：spending fuel要3个月才能冷却到正常温度，2年冷却
到室温。 |
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d*b
发帖数: 21830 | 18 fission是一个原子核分裂成2个，decay是一个原子核分裂出一个原子核和光子等粒子
。如果一个Cs-137分裂成2个原子核，那是fission而不是decay.
fission也有自发，decay也有人工。你连核物理的基本概念都不清楚。不懂就别jjww了。 |
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d*b
发帖数: 21830 | 19 我这是给你解释fission和decay的区别，并不是说一个Cs-137能分裂成2个原子核（当
然，heavy ion experiment成天都做这类实验）为什么fission和decay有这么大的区别
？decay 1900年间就发现了，fission要等到1945年？ |
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T*********e
发帖数: 39815 | 20 不懂，等专家来科普
看wiki上这么写：
Potassium iodide was approved in 1982 by the US FDA to protect the thyroid g
lands from radioactive iodine from accidents or fission emergencies. In the
event of an accident or attack at a nuclear power plant, or fallout from a n
uclear bomb, volatile fission product radionuclides may be released, of whic
h 131I is one of the most common by-products and a particularly dangerous on
e due to thyroid gland concentration of it, which may lead to thyroid cancer
. By saturating th... 阅读全帖 |
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s*********t
发帖数: 4253 | 21 笑死人哈哈， 原子弹都已经太小了，Hydrogen Bomb 已达到
原子弹的1000 倍，精算准确。你还说人类“无能” 控制原子弹的威力。
你是不是以为科学家是随手抓把原料塞到弹头里去再用铆钉给固定？
A nuclear weapon is an explosive device that derives its destructive force
from nuclear reactions, either fission or a combination of fission and
fusion. Both reactions release vast quantities of energy from relatively
small amounts of matter. The first fission ("atomic") bomb test released the
same amount of energy as approximately 20,000 tons of TNT. The first
thermonuclear ("hydrogen") bomb t... 阅读全帖 |
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s****e
发帖数: 2934 | 22 ☆─────────────────────────────────────☆
cds (红毛呼呼猪) 于 (Mon Sep 25 22:12:54 2006) 提到:
MICELLE上弄个PORE，引入酸性集团，热相应集团，这些花样似乎都很普通了阿
☆─────────────────────────────────────☆
nomos (秩序) 于 (Wed Sep 27 07:40:49 2006) 提到:
俺也不知道啊，反正混了一S/J/A
fission
☆─────────────────────────────────────☆
yueke (小鱼儿) 于 (Tue Sep 26 20:03:05 2006) 提到:
这不是我国内老板做的么？实在不懂，啥意思啊，一个fusion发在angew，一个fission
发jacs
fusion, fission |
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p******u
发帖数: 14642 | 23 看这洋鬼子多悲愤，好像我鳖又偷了他家的鸡还啥的
http://nucleargreen.blogspot.com/2011/01/have-chinese-been-read
Have the Chinese Been Reading Energy from Thorium or Nuclear Green?
Last week the Chinese Academy of Science announced that it planned to
finance the development of a Chinese Thorium Breeding Molten Salt Reactor (
TMSR) or as it is called in the United States, the Liquid Fluoride Thorium
Reactor (LFTR). The announcement came in a news report from Weihui.news365.
com.cn. The announcement was relayed to Western... 阅读全帖 |
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m****n
发帖数: 226 | 24 这次日本福岛核电站事故原来叫作"China Syndrome"
China Syndrome
The 'China Syndrome' refers to a possible result of the catastrophic
meltdown of a nuclear reactor. Also called a loss of coolant accident, the
scenario begins when something causes the coolant level in a reactor vessel
to drop, uncovering part—or all—of the fuel rod assemblies. Even if the
nuclear chain reaction has been stopped through use of control rods or other
devices, the fuel continues to produce significant residual heat for some
time due t... 阅读全帖 |
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d*b
发帖数: 21830 | 25 fission一直在那边进行，即使stop了，还有7%的fission, 为什么？知道cross
section么？ 你需要的是不断的冷却，把热量带走。这也是为什么水泵如此重要。泵停
了，里面的热量没法带走，接下去就是包rod的外壳烧坏。
这个跟CS-137，I-131完全没关系 |
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s***i
发帖数: 600 | 26 好吧。是我错了，我不了解你和DSB的恩怨，不该来揭你的短。
我看到你你在骂人，讲的东西有不对，就生气了。
不知道你是一个文科女生靠搜索力战 DSB，挺不容易的。
刚才搜了一下 DSB的帖子， 发现这家伙连自己稀里糊涂，还给别人科普fission,
decay, 说什么
fission 1945年才发现。误人子弟，的确比你可恶多了。
大刘说的好：“弱小与无知不是生存的障碍，傲慢才是”。
mm要是对原子弹感兴趣，推荐这本书：
http://www.amazon.com/Making-Atomic-Bomb-Richard-Rhodes/dp/0684
通俗读物，不是技术材料。从发现电子讲起，写的很好。我想文科生也看得懂。 |
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P***0
发帖数: 368 | 27 US 2001 data:
gasoline (cars and trucks) : 44%
Heating: 19%
Propane: 6%
Jet fuel: 8%
Residual fuel: 5%
Asphalt 3%
Other 15%
Before the petroleum industry, who will die before it, if Nuclear Fusion
were here tomorrow with 100% (or killer) efficiency?
Wind, solar, biofuel, fission, hydroelectric, coal, tidal power, geothermal.
Who will thrive: battery, power distribution, water treatment, energy
efficiency improvement.
BUT::: (1) Will every country and every industry (financially, technically
and... 阅读全帖 |
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b******y
发帖数: 143 | 28 I feel it is not difficult for Japan to make fission bomb, but very
difficult for Japan to make fusion bomb (surely they can figure out, but
need 6-18 month time and other technical stuff). Since fission bomb is heavy
and has low grade (maybe 50K TNT equivalent) and not very suitable for
ballistic missile.
Anyone can correct me if I am wrong? |
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p********n
发帖数: 2482 | 29 呵呵，你去修改wiki吧
http://en.wikipedia.org/wiki/Thermonuclear_weapon#Chinese_devel
The People's Republic of China detonated its first H-Bomb using a Yu–Deng
design June 17, 1967 ("Test No. 6"), a mere 32 months after detonating its
first fission weapon (the shortest fission-to-fusion development in history)
, with a yield of 3.31 Mt. |
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m***a
发帖数: 13878 | 30 看名字不像是三哥
(Reuters) - Lockheed Martin Corp said on Wednesday it had made a
technological breakthrough in developing a power source based on nuclear
fusion, and the first reactors, small enough to fit on the back of a truck,
could be ready for use in a decade.
Tom McGuire, who heads the project, said he and a small team had been
working on fusion energy at Lockheed's secretive Skunk Works for about four
years, but were now going public to find potential partners in industry and
government for thei... 阅读全帖 |
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l*******1
发帖数: 16217 | 31 维基百科各国氢弹发展都一大段，唯独中国就两句话，屌爆了，
The People's Republic of China detonated its first H-Bomb using a Yu–Deng
design June 17, 1967 ("Test No. 6"), a mere 32 months after detonating its
first fission weapon (the shortest fission-to-fusion development in history)
, with a yield of 3.31 Mt.
法国那个很可能来源于中国 |
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l*******1
发帖数: 16217 | 32 Yu-Deng Design 很早就名扬天下了，维基百科如下，
The People's Republic of China detonated its first H-Bomb using a Yu–Deng
design June 17, 1967 ("Test No. 6"), a mere 32 months after detonating its
first fission weapon (the shortest fission-to-fusion development in history)
, with a yield of 3.31 Mt.
如果邓的贡献大于或等于于敏，那按照字母顺序Deng 应该放在Yu之前，于敏是氢弹构
型突破的关键人物，核物理界这点还是摘得清的 |
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t***h
发帖数: 5601 | 33 http://www.ctbto.org/press-centre/press-releases/2013/ctbto-det
CTBTO detects radioactivity consistent with 12 February announced North
Korean nuclear test
Vienna, 23 April 2013
The CTBTO's radionuclide network has made a significant detection of
radioactive noble gases that could be attributed to the nuclear test
announced by the Democratic People's Republic of Korea (DPRK) on 12 February
2013.
The detection was made at the radionuclide station in Takasaki, Japan,
located at around 1,000 kilome... 阅读全帖 |
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s******s
发帖数: 13035 | 34 我都不用查原文，wiki第一句就是
“Natural nuclear fission reactor
A natural nuclear fission reactor is a uranium deposit where self-sustaining
nuclear chain reactions have occurred. This can be examined by analysis of
isotope ratios. The existence of this phenomenon was discovered in 1972 at
Oklo in Gabon by French physicist Francis Perrin. The conditions under which
a natural nuclear reactor could exist had been predicted in 1956 by Paul
Kazuo Kuroda.[1] The conditions found were very similar to what was
pred... 阅读全帖 |
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n*********0
发帖数: 1543 | 35 From Wiki
The People's Republic of China detonated its first device using a Teller–
Ulam design June 17, 1967 ("Test No. 6"), a mere 32 months after detonating
its first fission weapon (the shortest fission-to-fusion development in
history), with a yield of 3.31 Mt.
这个是错的了？这么说。
中国有非T-U构型？ |
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s**********n
发帖数: 868 | 36 I like the way you think.
But have you paid attention to law of physics?
Basically you need nuclear reaction (either fusion or fission) to make gold
out of other materials. Fusion from lighter atoms is pretty much forbidden
by energy conservation in the case of Au unless you infuse astronomical
amount of energy into it. For fission, are there any cheaper and abundunt
heavier atom to begin with?
I will not call it completely impossible given that our understanding of
nature is quite limited. But ... 阅读全帖 |
|
KV
发帖数: 5728 | 37 老大，Fission SV在温度5摄氏度左右，都会觉得冷，我买过，后来出掉了，衣服非常
轻，用的材料是太空棉之类的东西，好处是用的是pro shell，防雨防风还行。
Alpha SV可不同，这是一层壳，里面要配装备的，穿这层shell的主要作用，是排出汗
气，防止贴近身体部分被汗水湿透，造成失温，穿Alpha SV登上世界知名雪山之巅的太
多了，这大概是每一个登山爱好者的必备装备。
加拿大始祖鸟在户外登山远足穿越爱好者中，确实是第一品牌。
fission |
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s*********t
发帖数: 600 | 38 Fission yeast COP9/signalosome suppresses cullin activity through
recruitment of the deubiquitylating enzyme
Ubp12p.
Zhou C, Wee S, Rhee E, Naumann M, Dubiel W, Wolf DA.
Mol Cell. 2003 Apr;11(4):927-38.
The fission yeast COP9/signalosome is involved in cullin modification by
ubiquitin-related Ned8p.
Zhou C, Seibert V, Geyer R, Rhee E, Lyapina S, Cope G, Deshaies RJ, Wolf DA.
BMC Biochem. 2001;2:7. Epub 2001 Jul 18.
PCI proteins eIF3e and eIF3m define distinct translation initiation factor 3
comp... 阅读全帖 |
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F*Q
发帖数: 3259 | 39 大多数细菌是通过binary fission来产生新个体的，其中对fission起主要作用的一个蛋白质叫FtsZ。同时有些细菌(alpha-proteobactria)是通过budding来产生新个体的，我想知道是哪个或哪些蛋白或基因对budding起主导作用。有人知道相关信息吗？
切题的回复有包子答谢 |
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y***e
发帖数: 6082 | 40 这不是我国内老板做的么？实在不懂，啥意思啊，一个fusion发在angew，一个fission
发jacs
fusion, fission |
|
f*******d
发帖数: 339 | 41 Because fusion products are stable (i.e. do not have radioactivity), where as
fission products have radioactivity, that is why fission based nuclear
reactors
are not clean.
Fusions main difficaulty is to achieve high density and high temperature,
which has not
been successful yet. |
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c****s
发帖数: 5892 | 42 日本核事故泄漏的放射物质已到达大温地区! 西门菲沙大学(SFU)研究团队近日在该校位于本那比山以及温哥华市中心校区检测出「辐射雨」，同时在北温码头测得「辐射海藻」，它们含有微量具有放射性的碘-131(iodine-131)，相信福岛核事故是唯一来源。 不过研究人员和省府医官皆强调，公众毋须忧虑，目前测得的辐射水平并不足以对人体健康造成危害。
西门菲沙大学在3月19、20及25日的雨水样本检测中，发现碘-131放射活度增加，从原本的每升雨水每秒0贝克(Bq/L)增至10左右。 (西大网站数据)
此外，福岛核电站释放的辐射，亦随风扩散到中国沿岸，广东昨日已测得微量放射性碘-131，香港天文台预测一股气团正由中国东北向南移动，预料在周四上午抵达，不排除会将辐射带到香港。
西大的研究团队称，未来数星期将会继续监测本地的辐射物质。
西大核专家斯塔罗斯塔(Kris Starosta)表示，其研究团队从本月初开始，从西大本那比山上和温哥华市中心两地采集的雨水样本，以及从北温码头附近海域和温哥华岛西岸柏克里湾(Barkley Sound)采集的海藻样本中，监测辐射水平;在本月16日及18日的样本中均未... 阅读全帖 |
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s******8
发帖数: 7105 | 43 RDS-37 was the Soviet Union's first "true" (staged) hydrogen bomb, first
tested on November 22, 1955. The weapon had a nominal yield of approximately
3 megatons. It was scaled down to 1.6 megatons for the live test.
It was a multi-stage thermonuclear device which utilized radiation implosion
called Sakharov's "Third Idea" in the USSR (the Teller–Ulam design in the
USA). It utilized a dry lithium deuteride fusion fuel, with some of it
replaced with a "passive material" to reduce its total yield. ... 阅读全帖 |
|
|
h**g
发帖数: 94 | 45 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
16 Major Projects, each fund USD 5-10B from 2006-2020
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
CPU and OS
–
VLSI process technology
–
Next-generation (4G) wireless network
–
High-end digital machine tool
–
Advanced nuclear fission power plant
–
Water pollution control and treatment
–
Large aircraft
–
High-resolution earth-observation system
–
Manned space flight and lunar exploration |
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y******u
发帖数: 246 | 46 please learn about the different between beta decay and nuclear fission |
|
G*******g
发帖数: 556 | 47 斗胆补充两点：
1）燃料棒烧了一段时间之后的确是中空的，中心都是fission gas，含有很多裂变产物
。不过新的燃料棒的确是实心的。不过这因该对中子的空间分布影响不大，反倒是有核
燃料的地方种子更密集，因为链式反应，就像您说的。其实只要控制棒能够把中子增值
速度降到临街条件以下，链式反应应该马上就会停止，因为种子在反应堆中的平均自由
程很短，种子分型速度又很快。余热因该大部分是因为还没有来得及衰变的裂变产物继
续衰变时产生的。
2）Meltdown之后，堆芯由燃料-水-燃料这种heterogeneous结构变成燃料和水混杂在一
起的homogeneous结构，根据我的记忆，一般反应堆里homogeneous的材料结构更不利于
链式反应，这也是为什么把堆芯设计成这种燃料和水交替存在的结构的原因之一（更容
易达到临界）。所以meltdown之后反应性是否会增强也有待考察。
我觉得meltdown对堆芯是毁灭性打击毫无一问，但是对外界环境的影响并没有这个词本
身那么可怕。 |
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f*********t
发帖数: 143 | 48 每个人都逃脱不了影响，或大或小
Service/fission-criticality-in-cooling-ponds-threaten-explosion-at-
fukushima.html |
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D*A
发帖数: 1169 | 49 Find a wiki term:
Chernobyl compared with an atomic bomb
Far fewer people died as an immediate result of the Chernobyl event than
died of radiation at Hiroshima, and the eventual total is also
significantly less when including those predicted by the WHO to die in
the future.
Due to the differences in half-life the different radioactive fission
products undergo exponential decay at different rates. Hence the
isotopic signature of an event where more than one radioisotope is
involved will change w... 阅读全帖 |
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n*****1
发帖数: 1329 | 50 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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