s**********n
发帖数: 3199 | 1 来自主题: LeisureTime版 - 形而上学 the one, the forms, 神国论教我想起时间简史开篇:
A well-known scientist (some say it was Bertrand Russell) once gave a public
lecture on astronomy. He described how the earth orbits around the sun and
how the sun, in turn, orbits around the center of a vast collection of stars
called our galaxy. At the end of the lecture, a little old lady at the back
of the room got up and said:"what you have told us is rubbish. The world is
really a flat plate supported on the back of a giant tortoise." The
scientist gave a... 阅读全帖 |
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I**********s
发帖数: 441 | 2 这是不太准确的部分. astrophysicist Neil deGrasse Tyson, astronomer and
skeptic Phil Plait, and veteran NASA astronaut and spacewalker Scott E.
Parazynski have offered comments about some of the most "glaring"
inaccuracies.Examples of such mistakes include:
The "momentum" that caused Clooney to cut his line makes no sense because he
and Bullock are stationary with respect to the space vehicle (nor is there
any propulsive force)
The Hubble Space Telescope (HST), which is being repaired at the
beginning... 阅读全帖 |
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I**********s
发帖数: 441 | 3 这是拍得不准确的地方:
astrophysicist Neil deGrasse Tyson, astronomer and skeptic Phil Plait, and
veteran NASA astronaut and spacewalker Scott E. Parazynski have offered
comments about some of the most "glaring" inaccuracies.[64][65][60] Examples
of such mistakes include:
The Hubble Space Telescope (HST), which is being repaired at the
beginning of the movie, has an altitude of about 559 kilometers (347 mi),
and an orbital inclination of 28.5 degrees. The ISS has an altitude of
around 420 kilometers (2... 阅读全帖 |
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b*****e
发帖数: 14299 | 4 ☆─────────────────────────────────────☆
kitkat (标头党) 于 (Thu Jul 5 00:28:13 2012, 美东) 提到:
油漆太不靠铺, ACY ROYAL 最好的室外专用的PORCH & DECK, 几年下来就这副卖相,
BENCH 的VARNISH 更不靠谱, 大部分时间在阴影下还这样了. 得哭比的用沙皮机沙掉才
能上STAIN. 同学们FENCE, PORCH, DECK 千万不能上漆啊, 沙死人.
☆─────────────────────────────────────☆
kitkat (标头党) 于 (Thu Jul 5 00:30:09 2012, 美东) 提到:
沙好了, 上STAIN 倒是快的, 交给闺女上了.
☆─────────────────────────────────────☆
bengalcat (不吃玛丽的獭獭) 于 (Thu Jul 5 00:31:26 2012, 美东) 提到:
湿父你太牛了。。。
你家里有多少工具呀
☆────────────────... 阅读全帖 |
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r*********e
发帖数: 29495 | 5 Music Heaven 美好的回忆
音乐天堂1~36的目录 Music Heaven Vol.1~Vol.362007-04-16 14:01Music Heaven Vol
.1
1 Everything I Do, I Do It For You - Bryan Adams
2 Pretty Woman - Ronan
3 Windflowers - Seals & Crofts
4 Rush Rush - Paula Abdul
5 I'd Love You To Want Me - Lobo
6 Black Or White - Michael Jackson
7 Tears In Heaven - Eric Clapton
8 Save The Best For Last - Vanessa Williams
9 Seasons In The Sun - Terry Jacks
... 阅读全帖 |
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G********t
发帖数: 334 | 6 Birthday, what's is indeed one's birthday?
It's the time when one's born and the time
is measure by the orbiting of the earth around
the sun. Everytime the earth passes throgh
the same spot on its orbit one has a birthday.
Some people also use the lunar calender
for their birthday. The definition of
birthday is then fuzzied up.
As long as the definition is not precise,
I alway took the liberty of either celebrate
"my aging" with a approximate date or
don't celebrate it at all. What's the |
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b*****y
发帖数: 689 | 7 The Tao school treat human body as universe, eletron orbiting around the
nucleaus is same as moon orbiting the sun |
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z**n
发帖数: 22303 | 8 【 以下文字转载自 Military 讨论区 】
发信人: zoun (zoun), 信区: Military
标 题: 军迷们圣诞礼物的一个选择
发信站: BBS 未名空间站 (Thu Nov 18 10:48:11 2010, 美东)
http://www.spacetoys.com/proddetail.php?PARTNER=spaceguide&prod=spaceshuttleorbiter
New: Space Shuttle Orbiter 1:1 Model for $2,200,000 + pickup
SpaceToys.com offers a Space Shuttle Orbiter 1:1 Scale Replica Model for $2,
200,000. Although shipping is the responsibility of the purchaser, that's $
26,600,000 below the lowest total price we could for an actual NASA space
shuttle... 阅读全帖 |
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w*******e
发帖数: 15912 | 9 【 以下文字转载自 Military 讨论区 】
发信人: wsnonline (卫所南次郎-子曰：“再得瑟我削你啊！”), 信区: Military
标 题: 中国批印度火星计划，三哥网民激动回复
发信站: BBS 未名空间站 (Fri Nov 8 22:27:15 2013, 美东)
文章提交者：忙碌一天 加贴在 陆军论坛 铁血论坛 http://bbs.tiexue.net/bbs32-0-1.html
印度抢先中国一步，成功向火星发射探测器，随后北京呼吁“共同努力”以确保外太空
和平。11月5日下午，火箭搭载着“曼加里安”号飞行器升空，使得印度成为排在美国
、俄罗斯和欧洲之后第四个向火星发射探测器的国家。预计明年9月进入红色星球的轨
道。“外太空是全人类的共同财富，各国拥有和平探索和利用外太空的权利。”中国外
交部发言人洪磊在新闻发布会上被问及如何看待印度探测火星时说。同时，他表示国际
社会应共同努力，维护外太空的永久和平与可持续发展。
外文标题：China calls for 'joint efforts' after India's Mars mission
[ 转自铁... 阅读全帖 |
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H********g
发帖数: 43926 | 10 也可能我理解错了。这个“gravitational radiation”是怎么回事？
https://en.wikipedia.org/wiki/Speed_of_gravity
The speed of gravity (more correctly, the speed of gravitational waves) can
be calculated from observations of the orbital decay rate of binary pulsars
PSR 1913+16 (the Hulse–Taylor binary system noted above) and PSR B1534+12.
The orbits of these binary pulsars are decaying due to loss of energy in the
form of gravitational radiation. The rate of this energy loss ("
gravitational damping") can be measured, ... 阅读全帖 |
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H********g
发帖数: 43926 | 11 【 以下文字转载自 Biology 讨论区 】
发信人: lyray (lyray), 信区: Biology
标 题: 人类灵魂就隐藏在DNA末端krypton原子
发信站: BBS 未名空间站 (Wed Aug 26 16:32:06 2015, 美东)
We owe the discovery of this mysterious biogenetic process to our scientist
AOYOO 221.
It had been discovered a long time before that in the human brain were
krypton atoms (a rare gas that you know), and this discovery was a
significant, transcendent one. It was quite simply the key to the OEMBUAW,
MAN'S THIRD FACTOR, which you do not know and which acts as a link be... 阅读全帖 |
|
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s******l
发帖数: 278 | 13 Chapter 16
Arthur awoke to the sound of argument and went to the bridge.
Ford was waving his arms about.
"You're crazy, Zaphod," he was saying, "Magrathea is a myth, a
fairy story, it's what parents tell their kids about at night if
they want them to grow up to become economists, it's ..."
"And that's what we are currently in orbit around," insisted
Zaphod.
"Look, I can't help what you may personally be in orbit around,"
said Ford, "but this ship ..."
"Computer!" shouted Zaphod.
"O |
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c****t
发帖数: 19049 | 14 NASA's decommissioned Upper Atmosphere Research Satellite, out of gas and
out of control, is not descending toward re-entry as rapidly as expected,
officials say, likely delaying the satellite's kamikaze plunge to Earth by a
few hours, to late Friday or early Saturday.
Experts expect more than two dozen chunks of debris to survive re-entry and
hit the ground in a 500-mile-long footprint somewhere along the satellite's
orbital track. But given the bus-size 6.3-ton's satellite's trajectory and
the... 阅读全帖 |
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a**********s
发帖数: 1075 | 15
品。
i read The Fountains of Paradise many years ago, the concept was good, but
it's not practical. the geostationary orbit is 36,000 km above earth, even
technology wise it is feasible, the resources and materials needed to build
such a space elevator and space station in the orbit will far exceed what
earth can offer. |
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D*****r
发帖数: 6791 | 18 Letters from the Earth
When the Creator had finished thinking, He said, "I have thought. Behold!"
He lifted His hand, and from it burst a fountain-spray of fire, a million
stupendous suns, which clove the blackness and soared, away and away and
away, diminishing in magnitude and intensity as they pierced the far
frontiers of Space, until at last they were but as diamond nailheads
sparkling under the domed vast roof of the universe.
At the end of an hour the Grand Council was dismissed.
They left... 阅读全帖 |
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j*******7
发帖数: 6300 | 19 http://www-scf.usc.edu/~kallos/what_is_real.htm
What is real?
Take for example the first successful theory of gravity, Ptolemy's system of
epicycles. It was used before Newton to describe the motion of the planets,
by assuming that the earth was static in the center of the world and the
planets and the sun revolved around it. It gave relatively accurate results
for astronomical observations. Was it real? I guess not. It just helped the
calculations, correctly, to be carried out.
Then Newton's th... 阅读全帖 |
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s******o
发帖数: 298 | 21 从www.space.com的一篇文章上cut一段：）
Ancient visitor returns
Soon after a preliminary orbit was calculated for Ikeya-Zhang, some orbital
experts, lead by Syuichi Nakano of Japan, noticed a similarity to a pair of
much earlier comets that appeared in 1532 and 1661.
The 1532 comet, in particular, was a strikingly bright comet, according to
Oriental records. Curiously, during the first week or two that Ikeya-Zhang
was under careful scrutiny by observers worldwide it appeared to be brightening
at an unusuall |
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s******o
发帖数: 298 | 22 March 15, 2002 | Mars Odyssey, the latest orbiter to start mapping the red
planet, is back to full working order. Its cameras have always worked fine,
but last August controllers lost communication with Odyssey's Mars Radiation
Environment Experiment (MARIE) while the craft was still en route to Mars.
The broken component — designed to measure the radiation danger that future
travelers to Mars might encounter — was largely ignored until the craft
reached its low mapping orbit in February and eng |
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s******o
发帖数: 298 | 23 By Robert Roy Britt
Senior Science Writer
posted: 02:00 pm ET
17 April 2002
Eccentricity has been redefined in our solar system with the measurements of
a pair of objects that orbit each other out in the dark and cold stomping
grounds of Pluto.
Last April, researchers announced that an object named 1998 WW31, a comet-like
body orbiting the Sun in the solar system's fringes, had a companion. A new
study, which will be published in the April 18 issue of the journal Nature,
finds that the pair's co |
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s******o
发帖数: 298 | 24 A halo globular cluster gets shredded by our galaxy.
by Phil Plait
Orbiting the Milky Way can be hazardous to your health. Although most objects
serenely orbit our home galaxy, astronomers are now detecting invisible deadly
forces wreaking havoc upon some of them. Gravity, which keeps star, clusters,
and nebulae bound to the Milky Way, can also tear them apart.
The newest victim found is Palomar 5, a roughly 13-billion-year-old globular
cluster 75,000 light-years away. New observations of the cl |
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s*****t
发帖数: 1994 | 26 The Seasons of Saturn
Credit: R. G. French (Wellesley College) et al., Hubble Heritage Team (AURA / STScI /
NASA)
Explanation: Since Saturn's axis is tilted as it orbits the Sun, Saturn has seasons, like those
of planet Earth ... but Saturn's seasons last for over seven years. So what season is it on Saturn
now? Orbiting the equator, the tilt of the rings of Saturn provides quite a graphic seasonal
display. In fact, this month, Saturn's ring |
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s*****t
发帖数: 1994 | 27 Five to Mars
Image Credit: USGS, Viking Project, NASA
Explanation: Come December 2003 - January 2004, an armada of five new invaders from
Earth should arrive on the shores of the Red Planet -- the Japanese ( ISAS) Nozomi orbiter,
the European Space Agency's Mars Express orbiter carrying the Beagle 2 lander, and NASA's
own two Mars Exploration Rovers. While Nozomi began its interplanetary voyage in 1998,
the other spacecraft are scheduled for launch windows beginning this June. Cl |
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s*****t
发帖数: 1994 | 28 A Mercury Transit Sequence
Credit & Copyright: Dominique Dierick
Explanation: Earlier this month, the planet Mercury crossed the face of the Sun, as seen
from Earth. Because the plane of Mercury's orbit is not exactly coincident with the plane of
Earth's orbit, Mercury usually appears to pass over or under the Sun. The above time-lapse
sequence, taken from a balcony in Belgium on May 7, shows the entire transit. The solar
crossing lasted over five hours, so that the above 23 im |
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s*****t
发帖数: 1994 | 29 Martian Moon Phobos from MGS
Credit: Malin Space Science Systems, MGS, JPL, NASA
Explanation: Why is Phobos so dark? Phobos, the largest and innermost of two Martian
moons, is the darkest moon in the entire Solar System. Its unusual orbit and color indicate
that it may be a captured asteroid composed of a mixture of ice and dark rock. The above
picture was captured recently by the robot spacecraft Mars Global Surveyor (MGS) orbiting
Mars. Phobos is a heavily cratered and barren moon, |
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s*****t
发帖数: 1994 | 30 HD70642: A Star with Similar Planets
Illustration Credit & Copyright: David A. Hardy, PPARC
Explanation: Astronomers have discovered a planetary system more similar to our own
Solar System than any known previously. The bright star HD70642, visible with binoculars
toward the constellation of Puppis, was already known to be a star like our Sun. Now a planet
with twice Jupiter's mass has been discovered in a nearly circular orbit at approximately half
the orbital distance of Jupiter. Su |
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s*****t
发帖数: 1994 | 31 Mars Rising Through Arch Rock
Credit & Copyright: Wally Pacholka (Astropics)
Explanation: Mars is heading for its closest encounter with Earth in over 50,000 years.
Although Mars and Earth continue in their normal orbits around the Sun, about every two
years Earth and Mars are on the same part of their orbit as seen from the Sun. When this
happens again in late August, Mars will be almost as near to the Sun as it ever gets, while
simultaneously Earth will be almost as far from the |
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s*****t
发帖数: 1994 | 32 Light Can Twist as Well as Spin
Credit & Copyright: M. J. Padgett, J. Leach (U. Glasgow) et al., Royal Society
Explanation: Light is more complicated than we thought. When astronomers measure light, they are usually
concerned with its direction, energy, and spin polarization (sometimes). Recently, however, it has been more
broadly realized that photons can also have orbital angular momentum (OAM), an attribute classically analogous
to the Earth orbiting the Sun as well as spinning on |
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s*****t
发帖数: 1994 | 33 The International Space Station from Above
Credit: STS-114 Crew, NASA
Explanation: The International Space Station (ISS) is the largest human-made
object ever to orbit the Earth. Last August, the station was visited and
resupplied by space shuttle Discovery. The ISS is currently operated by the
Expedition 13 crew, consisting a Russian and an American astronaut. After
departing the ISS, the crew of Discovery captured this spectacular vista of
the orbiting space city high above the Caspian Sea. Vi |
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s*****t
发帖数: 1994 | 34 Janus: Potato Shaped Moon of Saturn
Credit: CICLOPS, JPL, ESA, NASA
Explanation: Janus is one of the stranger moons of Saturn. First, Janus
travels in an unusual orbit around Saturn where it periodically trades
places with its sister moon Epimetheus, which typically orbits about 50
kilometers away. Janus, although slightly larger than Epimetheus, is potato-
shaped and has a largest diameter of about 190 kilometers. Next, Janus is
covered with large craters but strangely appears to lack small cra |
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s*****t
发帖数: 1994 | 35 Spirit Rover on Mars Imaged from Orbit
Credit: HiRISE, MRO, LPL (U. Arizona), NASA
Explanation: If you have the right equipment, you can see the Spirit rover
currently rolling across Mars. The right equipment, however, is currently
limited to the High Resolution Imaging Science Experiment onboard the Mars
Reconnaissance Orbiter (MRO). MRO arrived at Mars in March and just started
science observations of the red planet last month. Visible in the above
spectacularly high resolution image is the Sp |
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s*****t
发帖数: 1994 | 36 CoRoT Satellite Discovers Rocky Planet
Illustration Credit: ESO/L. Calcada
Explanation: How similar is exoplanet CoRoT-7b to Earth? The newly
discovered extra-solar planet is the closest physical match yet, with a mass
about five Earths and a radius of about 1.7 Earths. Also, the home star to
CoRoT-7b, although 500 light years distant, is very similar to our Sun.
Unfortunately, the similarities likely end there, as CoRoT-7b orbits its
home star well inside the orbit of Mercury, making its year l |
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Z**R
发帖数: 1233 | 37 Mission Sequence
#
Chandrayaan-1 spacecraft would be launched from the Satish Dhawan Space
Centre, SHAR, Sriharikota by PSLV-XL (PSLV-C11) in an highly elliptical
initial orbit (IO) with perigee (nearest point to the Earth) of about 257 km
and an apogee (farthest point from the Earth) of about 22,858 km.
#
After a few revolutions in the initial orbit, the spacecraft's Liquid
Apogee Motor (LAM) firing would be done, when the spacecraft is near perigee
, to raise the apogees to 37,421 |
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Z**R
发帖数: 1233 | 38 October 26, 2008
Chandrayaan-1 spacecraft has entered deep space after crossing the 150,000
km (one and a half lakh km) distance mark from the Earth. This happened
after the successful completion of the spacecraft’s third orbit raising
manoeuvre today (October 26, 2008) morning.
During this manoeuvre which was initiated at 07:08 IST, the spacecraft’s
440 Newton liquid engine was fired for about nine and a half minutes. With
this, Chandrayaan-1 entered a much higher elliptical orbit around the |
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s*****r
发帖数: 469 | 39 Chandrayaan-1 was successfully raised to its fourth orbit this morning
around
7.30. “Everything went on as planned,” M. Annadurai, Project Director of
Chandrayaan-1 said.
The spacecraft was raised to the predetermined apogee of 2,67,000 km. And
thus
it has overcome the shortfall of 35,000 km apogee in the third orbit.
6天后第五次变轨。
http://www.khabrein.info/index.php?
option=com_content&task=view&id=18139&Itemid=62 |
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t*n
发帖数: 14458 | 40 有惊无险
Chandrayaan-1 was successfully raised to its fourth orbit this morning
around
7.30. “Everything went on as planned,” M. Annadurai, Project Director of
Chandrayaan-1 said.
The spacecraft was raised to the predetermined apogee of 2,67,000 km. And
thus
it has overcome the shortfall of 35,000 km apogee in the third orbit.
6天后第五次变轨。
http://www.khabrein.info/index.php?
option=com_content&task=view&id=18139&Itemid=62 |
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Z**R
发帖数: 1233 | 41 All credits belong to the original author:
http://www.pagef30.com/2009/08/liveblogging-launch-of-first-flight-of_25.html
8:00 pm: Uh oh, looks like the satellite wasn't sent into the correct orbit
as they had suspected before. The launch and separation was a success but
the orbit seems to be too high, at 342 km instead of the planned 306 km. We
still have to wait ten more hours before communication with the satellite is
established as well.
6:20 pm: We have YouTube! Here's the launch. Note that |
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l**********1
发帖数: 5204 | 42 那是 Poincaré 龐加萊猜想的解铃人 俄罗斯数学家 Perelman 佩雷尔曼
//en.wikipedia.org/wiki/Grigori_Perelman
please go to
//en.wikipedia.org/wiki/Henri_Poincaré
//en.wikipedia.org/wiki/Poincaré_conjecture
and
名稱三體問題
英語名稱：three-body problem
N體問題及三體問題的概念N體問題：
N體問題可以用一句話寫出來：在三維空間中給定N個質點，如果在它們之間只有萬
有引力的作用，那麽在給定它們的初始位置和速度的條件下，它們會怎樣在空間中運動。
三體問題：
最簡單的例子就是太陽系中太陽，地球和月球的運動。在浩瀚的宇宙中，星球的大
小可以忽略不記，所以我們可以把它們看成質點。如果不計太陽系其他星球的影響，那
麽它們的運動就只是在引力的作用下産生的，所以我們就可以把它們的運動看成一個三
體問題。
天體力學中的基本力學模型。研究三個可視爲質點的天體在相互之間萬有引力作用
下的運動規律問題。這三個天體的質量、初始位置和... 阅读全帖 |
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l***y
发帖数: 1166 | 43 We owe the discovery of this mysterious biogenetic process to our scientist
AOYOO 221.
It had been discovered a long time before that in the human brain were
krypton atoms (a rare gas that you know), and this discovery was a
significant, transcendent one. It was quite simply the key to the OEMBUAW,
MAN'S THIRD FACTOR, which you do not know and which acts as a link between
the HEART and the BODY (BUAWAA and OEMII).
69 XEE before [approximately 18 months NdT ], in laboratory fertilization
experime... 阅读全帖 |
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l***y
发帖数: 1166 | 44 We owe the discovery of this mysterious biogenetic process to our scientist
AOYOO 221.
It had been discovered a long time before that in the human brain were
krypton atoms (a rare gas that you know), and this discovery was a
significant, transcendent one. It was quite simply the key to the OEMBUAW,
MAN'S THIRD FACTOR, which you do not know and which acts as a link between
the HEART and the BODY (BUAWAA and OEMII).
69 XEE before [approximately 18 months NdT ], in laboratory fertilization
experime... 阅读全帖 |
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a****o
发帖数: 6612 | 45 The difference between a single reference method and a multi-reference
is the way to generate the excited determinants (e.g. excite one
electron from the occupied orbital to a virtual orbital to form a new
determinant). If you start from a HF determinant, but allows all
possible excitations (single, double, triple, quadruple, ...), you will
get a full CI. The problem is that a full CI has too many determinants
and is inaccessible to all chemical systems except the simplest one.
That is why we |
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a****o
发帖数: 6612 | 46 CASSCF can use CSFs (or determinants) for states of more than one
symmetry
(both spin and spatial). But I do not see the point of running such
calculations unless you are going to consider spin-orbit effect.
The term CI by itself is not limited to single reference. In fact, there
are CI inside MCSCF!! Conventionally we use terms CISD, QCISD for
single reference CI methods and MRCI for multireference CI. CI does not
optimize orbitals. |
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n*****g
发帖数: 4117 | 47 ☆─────────────────────────────────────☆
axin (Axin) 于 (Sat May 9 02:44:03 2009) 提到:
stability order of alkenes 里面讲越多substitute, 分子越稳定。
讲原因的时候，提到MO 理论，hyperconjugation grouping,every C=C has an empty
p antibonding orbital, 我一直理解为 C=C bond can only have eiher bonding p
or nonbonding p orbital. because when they have the same sign, they form
bonding p; opisite sign, nonbonding p.
难道是c=c 加一起bonding and nonbonding 各一个么？
书上讲的很少，也不影响做题考试，就是很好奇想知道。
☆─────────────────────────────────────☆
sleepi |
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S*****n
发帖数: 6055 | 48 正经回答一下吧
supertech其实说的都对，只不过用joke的方式说出来的
tteou说的也都对，说的挺充分，第四题他没说答案的，应该选D，具体原因看Juve和我
的帖子，think of molecular orbital, filling electrons in 2p* anti-bonding
orbitals，不知道你家小孩学过相关内容没有。。。
my |
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