a*****g
发帖数: 19398 | 1 Stanford neuroscience research identifies more effective way to teach
abstract math concepts to children
A new study shows that students who use symmetry to learn about numbers tap
into critical brain circuits. The approach appears promising in improving
math skills in general.
By Edmund L. Andrews
(Courtesy AAALab@Stanford)
Building on new discoveries about how the brain grapples with abstract
mathematics, researchers at Stanford Graduate School of Education (https://
ed.stanford.edu/) have dev... 阅读全帖 |
|
a*****g
发帖数: 19398 | 2 Stanford neuroscience research identifies more effective way to teach
abstract math concepts to children
A new study shows that students who use symmetry to learn about numbers tap
into critical brain circuits. The approach appears promising in improving
math skills in general.
By Edmund L. Andrews
(Courtesy AAALab@Stanford)
Building on new discoveries about how the brain grapples with abstract
mathematics, researchers at Stanford Graduate School of Education (https://
ed.stanford.edu/) have dev... 阅读全帖 |
|
a*****g
发帖数: 19398 | 3 Stanford neuroscience research identifies more effective way to teach
abstract math concepts to children
A new study shows that students who use symmetry to learn about numbers tap
into critical brain circuits. The approach appears promising in improving
math skills in general.
By Edmund L. Andrews
(Courtesy AAALab@Stanford)
Building on new discoveries about how the brain grapples with abstract
mathematics, researchers at Stanford Graduate School of Education (https://
ed.stanford.edu/) have dev... 阅读全帖 |
|
s******r
发帖数: 21961 | 4 【 以下文字转载自 Football 讨论区 】
发信人: BigBlue (#15), 信区: Football
标 题: 正能量第九贴: Perfect Symmetry
发信站: BBS 未名空间站 (Wed Nov 1 11:31:24 2017, 美东)
咱这个棒球版谈论萎琐大赛这么欢乐
我也说一场奇葩的比赛 所谓"Perfect Symmetry"
8/13/1910, 痞子堡对布鲁克林(那时候还不叫Dodgers)
比赛结束时双方各有:
8 runs,
13 hits,
2 errors,
12 assists,
5 strikeouts,
3 walks,
1 hit baseman,
1 passed ball.
那时候 以平局收场很常见
因为天黑了看不清球 或者客队要赶火车去下一个城市 都是原因
哦扯远了 当初知道有这么场球
是读George F. Will的"Men at Work"
他和Larry David 是(除了我家老爷子之外)
影响我的思想思维最大的俩人 嗯
他很不爽橄榄球的风头已经远远压过棒球 曾经说
橄榄球凝聚了美国社... 阅读全帖 |
|
B*****e
发帖数: 9375 | 5 咱这个棒球版谈论萎琐大赛这么欢乐
我也说一场奇葩的比赛 所谓"Perfect Symmetry"
8/13/1910, 痞子堡对布鲁克林(那时候还不叫Dodgers)
比赛结束时双方各有:
8 runs,
13 hits,
2 errors,
12 assists,
5 strikeouts,
3 walks,
1 hit baseman,
1 passed ball.
那时候 以平局收场很常见
因为天黑了看不清球 或者客队要赶火车去下一个城市 都是原因
哦扯远了 当初知道有这么场球
是读George F. Will的"Men at Work"
他和Larry David 是(除了我家老爷子之外)
影响我的思想思维最大的俩人 嗯
他很不爽橄榄球的风头已经远远压过棒球 曾经说
橄榄球凝聚了美国社会的两个恶劣现象:
先是开集体碰头会 然后施展暴力
("Violence, punctuated by committee meetings.")
就差没有直接喊NFL是匪帮黑社会了
如果喊了 东北地区某大豪门的粉丝们肯定很认同罢 哈哈
哦扯远了 他还说过
只... 阅读全帖 |
|
B*****e
发帖数: 9375 | 6 咱这个棒球版谈论萎琐大赛这么欢乐
我也说一场奇葩的比赛 所谓"Perfect Symmetry"
8/13/1910, 痞子堡对布鲁克林(那时候还不叫Dodgers)
比赛结束时双方各有:
8 runs,
13 hits,
2 errors,
12 assists,
5 strikeouts,
3 walks,
1 hit baseman,
1 passed ball.
那时候 以平局收场很常见
因为天黑了看不清球 或者客队要赶火车去下一个城市 都是原因
哦扯远了 当初知道有这么场球
是读George F. Will的"Men at Work"
他和Larry David 是(除了我家老爷子之外)
影响我的思想思维最大的俩人 嗯
他很不爽橄榄球的风头已经远远压过棒球 曾经说
橄榄球凝聚了美国社会的两个恶劣现象:
先是开集体碰头会 然后施展暴力
("Violence, punctuated by committee meetings.")
就差没有直接喊NFL是匪帮黑社会了
如果喊了 东北地区某大豪门的粉丝们肯定很认同罢 哈哈
哦扯远了 他还说过
只... 阅读全帖 |
|
a*****g
发帖数: 19398 | 7 文章摘要——
How can children's natural perceptuo-motor skills be harnessed for teaching
and learning mathematical structure? We address this question in the case of
the integers. Existing research suggests that adult mental representations
of integers recruit perceptuo-motor functionalities involving symmetry.
Building on these findings, we designed a hands-on curriculum that
emphasizes symmetry to teach integer concepts to fourth graders. Compared to
two control conditions, children who went through... 阅读全帖 |
|
r**a
发帖数: 536 | 8
Do you mean witten's paper? That mirror symmetry is different with the "
normal" mirror symmetry. Normal mirror means for the CY3 compactification of
typeII strings there will be a pair of CY3s corresponding to the same low
energy physics. And mathematicians want to know the rigorous statements and
proof about it. It will relate with Gopakumar-Vafa, Donaldson-thomas, blabla
...
"Mirror symmetry" in GL is different. This mirror borrowed the initial
physical meaning of mirror symmetry. But the co |
|
r**a
发帖数: 536 | 9 可能我没有表达清楚。我和你的侧重点不同。正如你所说Mirror in GL就是借用了最一
开始Mirror symmetry 在SCFT中的意思。但是"normal” mirror symmetry有很多方面
侧重于spacetime的意义，而不是worldsheet上面的。"normal” mirror symmetry对于
理解弦论如何能得到低能物理起着很重要的作用。他解释了typeIIA and typeII B之间
的关系。这也就是为啥向gromov-witten, donaldson-thomas, gupakumar-vafa都能联
系在一起的原因。我的意思是说从spacetime的这个角度来看，normal mirror 和
mirror in GL是很不一样的。我个人感觉，如果说某个人是做mirror symmetry的话，
似乎意味着此人的工作应着重于gromov-witten, donaldson-thomas, gupakumar-vafa
等等，而不是说GL or N=4 SYM。至少这句话在物理圈子里面适用。
你的话更强调的是从worldsheet角度理解。另 |
|
w****1
发帖数: 4931 | 10 The mirror symmetry of GL is what you call "normal" mirror symmetry. The
mirror symmetry acts on the Hitchin moduli space as fiber-wise T-duality, as
described by Strominger-Yau-Zaslow years ago. Both physicists and
mathematicians are interested in the mapping between branes on the two sides
of the mirror. A special feature of the Hitchin moduli space is that there
are a lot of singular fibers, which must be carefully treated. I'm no expert
on this -- perhaps someone else can elaborate. Another |
|
w****1
发帖数: 4931 | 11 As I said, there are two new features of the mirror symmetry for GL that we
are not used to, namely very singular fibers and cc branes, which is
presumably what's interesting about it.
There is a lot more to mirror symmetry than enumerative invariants, even for
Calabi-Yau 3-folds. We are interested in the category of branes, which has
a variety of presumably equivalent descriptions, in terms of bounded derived
category of coherent sheaves, in terms of special Lagrangians, in terms of
matrix fact |
|
|
h*****g
发帖数: 1523 | 13 SYMMETRY GNX Tire - P215/65R16 96T BSW
网上打折后的价格是$107.34, 比较了walmart和sam's,sears这个算是比较便宜了.
另外sears今天有一个$20 off on over $200 order的coupon code :SUNSHINE, 就相当
于194.68两个轮胎.
最后共计$262.94
剩下的就是:
Performance Balance (Life of the Tire Balance Mounting Included)
$14.00 * 2
High Pressure LT Valves
$4.99 * 2
HANDLING FEE
$4.75 * 2
TIRE DISPOSAL FEE
$2.00 * 2
Tax: $14.78
PA Environmental Fee: $2*2
最后共计$262.94, 买轮胎真是麻烦!交这么多费. |
|
a*****g
发帖数: 19398 | 14 所谓 symmetry 其实还是 spatial thinking
看看明年我和西北大学这边研究的结果会不会更有趣。
tap
children |
|
a********r
发帖数: 626 | 15 SB
SB
SB
win one wild-card game and done
lost in AFCCG
lost in SB
one and done
--------------
one and done
lost in SB
lost in AFCCG
....
Will the symmetry be fullfilled? |
|
n****n
发帖数: 492 | 16 Jeanette Winterson is one of my favorite writers of the English language.
I've read most of her novels and here are some thoughts on the book -
"Gut Symmetries". My praise is unreserved, because my admiration for the
work is unreserved.
The most immediately remarkable aspect of Jeanette Winterson's new novel
is the development of the scientific side of her thinking.(Some people
might not like it but I do.) While she has used the idea that we are all
space and points of light in "Sexing the Che |
|
n****n
发帖数: 492 | 17 From this premise she creates a story that is both evocative and pro-
vocative, challenging the reader to take models of the universe and
see their symmetries with models of the most traditional of human
concerns, love.
Winterson writes with an unerring hand, taking up metaphors effortlessly,
spinning them on her loom, so that they come out the other side as
something beautiful in their own right. Although a distinct stylist from
the beginning, her mellifluous prose has a cadence reminiscent of |
|
s********k
发帖数: 212 | 18
//hand, i love Hokin's "arrow of time", appealling and enchanting :)
But, this book -- "Gut Symmetries" is not mainly about the science
wonder and facts of the universe :)
Its more about through a totally different prospect, a science-like
viewpoint, to understand and feel the emotions and passions since the
existence of human beings :) Written like a human fantasy land :PP
Yet somehow i can remotely understand the passions or even feverish
enthusiasm in genuine science and art, coz i believe t |
|
s**d
发帖数: 3 | 19 【 以下文字转载自 EnglishChat 讨论区 】
【 原文由 neuron 所发表 】
Jeanette Winterson is one of my favorite writers of the English language.
I've read most of her novels and here are some thoughts on the book -
"Gut Symmetries". My praise is unreserved, because my admiration for the
work is unreserved.
The most immediately remarkable aspect of Jeanette Winterson's new novel
is the development of the scientific side of her thinking.(Some people
might not like it but I do.) While she has used the idea that we are a |
|
s**d
发帖数: 3 | 20 【 以下文字转载自 EnglishChat 讨论区 】
【 原文由 neuron 所发表 】
From this premise she creates a story that is both evocative and pro-
vocative, challenging the reader to take models of the universe and
see their symmetries with models of the most traditional of human
concerns, love.
Winterson writes with an unerring hand, taking up metaphors effortlessly,
spinning them on her loom, so that they come out the other side as
something beautiful in their own right. Although a distinct stylist from
the beginning, her |
|
b*******i
发帖数: 548 | 21 中国人里
做Langlands的只有江迪化一个
做几何Langlands的只有两个 博士快毕业了
Mirrow Symmetry是上个世纪末的事情了
现在不知道还有谁做 |
|
w****1
发帖数: 4931 | 22 don't you know that geometric Langlands IS mirror symmetry? :D
Seriously though, can someone give an in-depth explanation of why geometric
Langlands is important? |
|
w****1
发帖数: 4931 | 23 It is not different. Mirror symmetry is a statement about 1+1 dimensional
superconformal field theories. The geometric version has to do with SCFTs
arising from sigma models on Calabi-Yau manifolds. The Calabi-Yau manifold
in the GL context is the Hitchin moduli space, which is hyperkahler and is a
special case of the more general story. N=4 SYM motivates this story but is
not a necessarily ingredient.
of
and
blabla
different. |
|
r**a
发帖数: 536 | 24
as
这个我已经说过，SYZ的东西可以被称为mirror的定义了。但是不是每一种mirror
symmetry都能像normal mirror那样对物理产生那么大的影响的。我之所以说mirror in
GL和normal mirror不同，就是因为对于物理的影响不同，所处的地位也不同。还是那
句话，同与不同，要看你站在哪个角度说话。如果你站在SYZ上，所有的mirror都是一
样的。不就是t对偶嘛。
Both physicists and
sides
A special feature of the Hitchin moduli space is that there
expert
which
ordinary |
|
L*******t
发帖数: 2385 | 25 期待达人回答。。
Put-call-symmetry做American的，r和q可以不为零。 |
|
t******l
发帖数: 10908 | 26 弃婴你的另一个问题是，如果不是 mathematical science，没法写出方程的情况下，
你也无法预测 spontaneous symmetry breaking 是不是一定会发生。
就好比人类右撇子远多于左撇子，这个 spontaneous symmetry breaking 发生了。。
。但人类总阴茎数量跟总阴道数量还是基本一半一半的，这个 spontaneous symmetry
breaking 就没有发生，虽然理论上也可以 spontaneous symmetry breaking 到两男一
女立式前后夹攻，成为人生常态而不是爱情动作片变态。。。
: 你纯属放屁
: 这叫Chiral symmetry breaking, 妈的自然界很多东西都是chiral不对称，小到
quark
: 都这样
: 生物学领域自然也具备Chiral symmetry breaking，只不过杀老鼠的数学功底差
，认识
: 不到而已
|
|
s**u
发帖数: 9035 | 27 发信人: matrice (matrice), 信区: Physics
标 题: 拙作“杨振宁先生与复旦大学物理系教师的座谈”zz
发信站: BBS 未名空间站 (Mon Aug 22 22:23:35 2011, 美东)
http://blog.sciencenet.cn/home.php?mod=space&uid=4395&do=blog&i
拙作“杨振宁先生与复旦大学物理系教师的座谈”
已有 302 次阅读 2011-8-22 13:24 |个人分类:生活点滴|系统分类:科研笔记|关键词:
复旦大学 杨振宁 杂志发表 物理系 文章
最近在物理杂志发表的“杨振宁先生与复旦大学物理系教师的座谈”是以本人为作者的
文章。它基于杨先生与复旦大学物理系教师的对话。将它转变为一篇文章是一个创作过
程。每一个词、每一个标点都倾注了我们的心血。由于不必细说的种种方面，本文的成
文花费了我们大量的精力。本人学习研读过杨先生很多著作，与杨先生交往多年，也对
物理学史有所熟悉，但为在本文中保持和传达杨先生的风格仍然付出了大量心血。希望
本文能很好地表达杨先生的风格。
我们也很感谢物理杂志的合作。
... 阅读全帖 |
|
e******g
发帖数: 75 | 28 又看了一下taihei的文章，似乎确实有误导的地方。我也不想弄清楚到底他是什麽意思
了，不如自己写两句。
假如有一个exact global symmetry自发破缺了，根据Nambu- Goldstone theorem,一定
有一个相应的质量为0的粒子对应，称为goldstone boson。如果Higgs是 goldstone
boson,而质量又不为零，那麽这种global symmetry不能完全是自发破缺的，必须还有
一个explicite breaking term 。换句话说，这个global symmetry是一个approximate symmetry.
另外，Higgs是有可能从gauge sector得到的--所谓的gauge-Higgs unification,不过
必须是高维空间的，并且这个gauge symmetry是破缺的。
>在quantum field theory中（in high energy physics, not condensed matter...)，
>一般认为在很高能量，不会有global symmetry，因为gravity总会b |
|
b******r
发帖数: 45 | 29 In QED, I can simply demand that the theory describes a massless spin-1 part
icle and deduce the U(1) gauge symmetry from it. The same logical route exis
ts for QCD, but it's mathematically too complicated so that people adopt the
reverse route: to impose the SU(3) gauge symmetry in the Lagrangian. In sho
rt, gauge symmetries are a mathematical convenience that is so convenient th
at people just build theories on it.
The term "broken gauge symmetry" appears in many places, but it's a bad and
mis... 阅读全帖 |
|
m*****e
发帖数: 1506 | 30 http://blog.sciencenet.cn/home.php?mod=space&uid=4395&do=blog&i
拙作“杨振宁先生与复旦大学物理系教师的座谈”
已有 302 次阅读 2011-8-22 13:24 |个人分类:生活点滴|系统分类:科研笔记|关键词:
复旦大学 杨振宁 杂志发表 物理系 文章
最近在物理杂志发表的“杨振宁先生与复旦大学物理系教师的座谈”是以本人为作者的
文章。它基于杨先生与复旦大学物理系教师的对话。将它转变为一篇文章是一个创作过
程。每一个词、每一个标点都倾注了我们的心血。由于不必细说的种种方面，本文的成
文花费了我们大量的精力。本人学习研读过杨先生很多著作，与杨先生交往多年，也对
物理学史有所熟悉，但为在本文中保持和传达杨先生的风格仍然付出了大量心血。希望
本文能很好地表达杨先生的风格。
我们也很感谢物理杂志的合作。
施郁 （复旦大学物理系教授）
2011.8.22.
附原文如下。这里是html文件的唯一源，转载请注明。
【发表为：施郁，戴越，《物理》8卷（2011年）8期，491-499，特约专稿。本文是学
术文章，使用本文时请注意引用规... 阅读全帖 |
|
b***y
发帖数: 14281 | 31 That's why I said they (perhaps you included) had no idea about what they
talked about.
The real electron in the standard model is definitely Weyl fermion. There's
no question about that at all. Nor is Weyl fermions anything mysterious. It
is only that both left handed and right handed weyl electrons exist, which
can pair up and form a Dirac pair, and hence give electron a mass term.
However, ever since the famous discovery of Yang and Lee, it is well known
that the electro-weak sector violates ... 阅读全帖 |
|
m*t
发帖数: 2464 | 32
其实我觉得杨李合作的炸药文是开门见山的重要文献，开启了Symmetry break 的想法
。Symmetry break以前可是想都不敢想的，重要性相当于普朗克的量子论。
杨82的Yang-Mills场固然重要，但是缺少了Symmetry break 就走不下去。只是不明白
杨82为什么没在自己的Yang-Mills Theory上使用一下Symmetry break 的想法。可惜了。
物质质量的来源就是Symmetry break。 |
|
w********2
发帖数: 632 | 33 我的意思是raman和ir都是分子振动这一级别的，nmr是原子核自转一级别的，别歪曲。
Comparison of Raman and IR Spectroscopy
By
Dr. Mehboob Peeran
Reviewed By
Dr. K.G. Srinivasamurthy
Mutual exclusion principle
In a molecule with a center of symmetry it is seen that vibrations that are
Raman active are IR inactive and vice-versa, this is called the Principle of
mutual exclusion (eg, as in CO2 see details in the end). In molecules with
different elements of symmetry, certain bands may be active in IR, Raman,
both or neither. For a compl... 阅读全帖 |
|
g*q
发帖数: 26623 | 34 老杨的文章在CPL发表后,被以下作者引用
1，Fermi gases in one dimension: From Bethe ansatz to experiments
XW Guan, MT Batchelor, C Lee - Reviews of Modern Physics, 2013 - APS
2，Few interacting fermions in a one-dimensional harmonic trap
T Sowiński, T Grass, O Dutta, M Lewenstein - Physical Review A, 2013 - APS
3，Spectroscopy for a few atoms harmonically trapped in one dimension
NL Harshman - Physical Review A, 2014 - APS
4，Exact solution for the degenerate ground-state manifold of a strongly
interacting one-dimensi... 阅读全帖 |
|
e******g
发帖数: 75 | 35 太黑的文章不严格是特色，也经常犯错误，并且为别人指出他的错误而恼羞成怒，呵呵
。不过这一篇大体上还是不错的，除了最后关于“胖Higgs”的描述不知所云，（I
suppose he meant "fat higgs".)另外
，"Higgs粒子在“兆伏撞”上面没有观测到，也非常让人困惑",应该也是他的想象，实
际上，Tevatron的luminosity本来就很难确定是否存在Higgs,换句话说，如果在
Tevatron发现了5个sigma以上的signal,那一定不是SM Higgs.
回到你提出的几个问题：
>You said local symmtries are ture symmetry but global symmtries are usualy
>not. This is not right. Whether a symmetry is a true symmetry or an
>approximate symmetry has nothing to do with whether it is a local or global
>symmetry. There ar |
|
c****e
发帖数: 2097 | 36 This is the usual 'deep' view, however, it seems appropriate only perturbatively, except for the part of breaking it. it's not hard to find examples where respecting gauge symmetry more than as a redundancy gets you some headway. This is related to that there are inequivalent vacuum states related by so called singular gauge transformation. It is however not natural to distinguish them from "infinitesimal" ones especially in view of path integrals. Say you wanted to introduce things like chemica... 阅读全帖 |
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s*********e
发帖数: 2076 | 37 按照传统(其实是西方的传统)，求婚或订婚时男方要送女方一枚钻戒(称为engagement
ring)，女方是不送男方钻戒的(看来只有男方向女方求婚了)。结婚时双方互赠素圈戒
指(称为wedding bands)，这才是以后生活中经常戴的戒指。wedding bands因为 便宜
所以经常戴着也不用怕掉怕被抢，而engagement ring因为很贵所以一般都是在某些场
合才戴上的。
我上个月花了折合8400元买了一对白金wedding bands，没有任何样式，就是一对
圈 圈。需要说明的是白金不是铂金(platinum)，白金是white gold，还是gold的一种
， 不过因为颜色是白的而与黄金(yellow gold)区分开来，价钱上白金和黄金是一样的
， 都大大低于铂金的价格。另外需要说明的是要去好的商家买，以后若是圈圈的尺寸
不合适了还可以拿过去改尺寸。
买engagement ring花了我很多时间，需要说明的是，如果有条件，一定要买个钻
戒 送给女方。如果你仔细看过一颗ideal cut的钻石的话，你一定会为它的brilliance
和 fire感到... 阅读全帖 |
|
x****6
发帖数: 4339 | 38 下面是1998年到现在的屋里炸药奖，除中微子外，2008， 2004，1999这几年难道不是
你说的基本粒子或相互作用吗？
2008
Yoichiro Nambu
"for the discovery of the mechanism of spontaneous broken symmetry in
subatomic physics"
Makoto Kobayashi and Toshihide Maskawa
"for the discovery of the origin of the broken symmetry which predicts the
existence of at least three families of quarks in nature"
2004
David J. Gross, H. David Politzer and Frank Wilczek
"for the discovery of asymptotic freedom in the theory of the strong
interaction"
1999
Gerardus 't H... 阅读全帖 |
|
P****d
发帖数: 137 | 39 原帖地址
http://www.mitbbs.com/article_t/JobHunting/32595949.html
“You are in a social networking, and you want to share a picture to your
friends and your friends of friends. How can you find out your friends and
your friends and friends efficiently.
这个也是不需要写code。我只想到了最笨的breadth first search 的方法，O(n^2).然
后被问怎么能做到低于n^2。提示说是用friend relation的symmetry。我觉得即使用了
symmetry也还是O(n^2)啊。不懂，请大牛提示！“
friend relation symmetry是说找另外一个人同时做BFS，然后自己和那个人一起做BFS
做一层看有没有共同好友吗？如果有共同好友那个人就是我的Friend of Friend吗？这
样更慢吧
自己这里做两层BF... 阅读全帖 |
|
a*****g
发帖数: 19398 | 40 摘要——
How can children's natural perceptuo-motor skills be harnessed for teaching
and learning mathematical structure? We address this question in the case of
the integers. Existing research suggests that adult mental representations
of integers recruit perceptuo-motor functionalities involving symmetry.
Building on these findings, we designed a hands-on curriculum that
emphasizes symmetry to teach integer concepts to fourth graders. Compared to
two control conditions, children who went through t... 阅读全帖 |
|
b******r
发帖数: 45 | 41 Of course gauge symmetry can be unbroken. But that's not my point. My point
is that you can't explicit break it without introducing new degrees of freed
om. For the case of un-gauged symmetries, you can do that by simply tuning s
ome charges off.
In QED, I can just work in the Coulomb gauge and forget about the U(1) gauge
symmetry. The U(1) symmetry is introduced only for mathematical convenience
. |
|
w*********g
发帖数: 30882 | 42 高歌，现任北京航空航天大学能源动力学院动力工程及工程热物理学科一级责任教授，
航空发动机气动热力国防重点实验室副主任，长期从事动力工程、工程热物理及流体力
学领域的教学与科研工作，并在基础科研和多学科的应用技术领域取得了一系列国际领
先水平的创新性科研成果。
他在1984年发明的"沙丘驻涡火焰稳定器"，获国家发明一等奖，钱学森同志称之为"一
项长中国人志气的重要发明"。该成果广泛应用于我国多种军用航空发动机中，取得了
数以亿元计的经济效益，至今仍保有先进水平。本刊记者于今年10月采访了高歌教授，
了解到了他近期从事的一些前沿科研工作的最新进展，尤其是他对龙卷风的研究及其工
程应用价值，让人耳目一新。
高歌教授在采访中提到，传统的航空发动机技术虽然还在不停地改进提高之中，但
受到原理和材料工艺上的限制，已经逐渐逼近了性能发展的极限。目前虽然涌现出一些
新型航空发动机技术，但仍然没有走出依靠压力膨胀过程来实现热功转换的思路。他强
调，人们应该另辟蹊径，寻找其他可用的工作原理。为此，他研究了自然界龙卷风的形
成与强化机制，发明了一项称为"余热增推"的技术，直接利用龙卷旋涡实现热功转换并
提取... 阅读全帖 |
|
f***y
发帖数: 4447 | 43 https://www.zhihu.com/question/33463090
曾经微分几何学家们猜想Ricci flat spaces都是flat的。后来丘证明了Calabi猜想，
硬生生举出一个非平凡的Ricci flat space的例子，即所谓的Calabi-Yau manifolds.
后来发现这个Calabi-Yau manifolds在物理里面超级有用，是弦论的基本模型。物理学
家们又发现这个CY mfld存在mirror symmetry，mirror symmetry的概念又反过来进入
数学，对辛几何复几何的发展产生了影响，而且mirror symmetry本身也是个新领域。
当然丘证明Calabi猜想的手段就是所谓的几何分析啊，这个方法基本是他开创的，就是
把PDE里面那些先验估计啊等等手段应用到微分几何里面去。 |
|
N*V
发帖数: 350 | 44 【 以下文字转载自 Military 讨论区 】
发信人: wayofflying (小破熊), 信区: Military
标 题: 人类第一台真空能发动机即将在中国攻关成功
发信站: BBS 未名空间站 (Sat May 14 22:28:25 2011, 美东)
高歌，现任北京航空航天大学能源动力学院动力工程及工程热物理学科一级责任教授，
航空发动机气动热力国防重点实验室副主任，长期从事动力工程、工程热物理及流体力
学领域的教学与科研工作，并在基础科研和多学科的应用技术领域取得了一系列国际领
先水平的创新性科研成果。
他在1984年发明的"沙丘驻涡火焰稳定器"，获国家发明一等奖，钱学森同志称之为"一
项长中国人志气的重要发明"。该成果广泛应用于我国多种军用航空发动机中，取得了
数以亿元计的经济效益，至今仍保有先进水平。本刊记者于今年10月采访了高歌教授，
了解到了他近期从事的一些前沿科研工作的最新进展，尤其是他对龙卷风的研究及其工
程应用价值，让人耳目一新。
高歌教授在采访中提到，传统的航空发动机技术虽然还在不停地改进提高之中，但
受到原理和材料工艺上的限制，已经逐渐逼近了性能发... 阅读全帖 |
|
c*****t
发帖数: 730 | 45 达人帮忙看一下:
1.04 克拉 $10,003
CUT: Ideal
COLOR: F
CLARITY: VVS2
POLISH: Very Good
SYMMETRY: Very Good
L/W RATIO :1.01---这个是啥?
depth: 61.0%
table: 56.0%
measurement: 6.51 x 6.57 x 3.99 mm
Fluorescence: FAINT
Girdel: thin
Culet: none
Price Per Carat: $9,618 per carat
GIA
0.95 克拉 $9,095
CUT: signature
COLOR: F
CLARITY: VVS2
POLISH: EX
SYMMETRY: EX
L/W RATIO :1.01---这个是啥?
depth: 61.7%
table: 56.0%
measurement: 6.32 x 6.28 x 3.89 mm
Fluorescence: None
Girdel: medium
Culet: Small
Price Per Carat: $9,... 阅读全帖 |
|
c*****t
发帖数: 730 | 46 开始着手买钻戒的时候才发现这么多的学问,请教一下,下面两个是我在bluenile上面
build的两个, 达人帮忙看一下:
1.04 克拉 $10,003
CUT: Ideal
COLOR: F
CLARITY: VVS2
POLISH: Very Good
SYMMETRY: Very Good
L/W RATIO :1.01---这个是啥?
depth: 61.0%
table: 56.0%
measurement: 6.51 x 6.57 x 3.99 mm
Fluorescence: FAINT
Girdel: thin
Culet: none
Price Per Carat: $9,618 per carat
GIA
0.95 克拉 $9,095
CUT: signature
COLOR: F
CLARITY: VVS2
POLISH: EX
SYMMETRY: EX
L/W RATIO :1.01---这个是啥?
depth: 61.7%
table: 56.0%
measurement: 6.32 x 6.28 x 3.89 mm
Fluorescence:... 阅读全帖 |
|
f*****g
发帖数: 9098 | 47 4, and it offers a perfect analysis.
subconsciously, i want to bring things to their utmost symmetry possible.
日 only has mirror symmetry. by adding the extra stroke and making it into
田, i get rotational symmetry of integer multiples of 90 degrees. |
|
m**d
发帖数: 21441 | 48 【 以下文字转载自 Military 讨论区 】
发信人: wayofflying (小破熊), 信区: Military
标 题: 人类第一台真空能发动机即将在中国攻关成功
发信站: BBS 未名空间站 (Sat May 14 22:28:25 2011, 美东)
高歌，现任北京航空航天大学能源动力学院动力工程及工程热物理学科一级责任教授，
航空发动机气动热力国防重点实验室副主任，长期从事动力工程、工程热物理及流体力
学领域的教学与科研工作，并在基础科研和多学科的应用技术领域取得了一系列国际领
先水平的创新性科研成果。
他在1984年发明的"沙丘驻涡火焰稳定器"，获国家发明一等奖，钱学森同志称之为"一
项长中国人志气的重要发明"。该成果广泛应用于我国多种军用航空发动机中，取得了
数以亿元计的经济效益，至今仍保有先进水平。本刊记者于今年10月采访了高歌教授，
了解到了他近期从事的一些前沿科研工作的最新进展，尤其是他对龙卷风的研究及其工
程应用价值，让人耳目一新。
高歌教授在采访中提到，传统的航空发动机技术虽然还在不停地改进提高之中，但
受到原理和材料工艺上的限制，已经逐渐逼近了性能发... 阅读全帖 |
|
C********g
发帖数: 9656 | 49 【 以下文字转载自 Military 讨论区 】
发信人: wayofflying (小破熊), 信区: Military
标 题: 人类第一台真空能发动机即将在中国攻关成功
发信站: BBS 未名空间站 (Sat May 14 22:28:25 2011, 美东)
高歌，现任北京航空航天大学能源动力学院动力工程及工程热物理学科一级责任教授，
航空发动机气动热力国防重点实验室副主任，长期从事动力工程、工程热物理及流体力
学领域的教学与科研工作，并在基础科研和多学科的应用技术领域取得了一系列国际领
先水平的创新性科研成果。
他在1984年发明的"沙丘驻涡火焰稳定器"，获国家发明一等奖，钱学森同志称之为"一
项长中国人志气的重要发明"。该成果广泛应用于我国多种军用航空发动机中，取得了
数以亿元计的经济效益，至今仍保有先进水平。本刊记者于今年10月采访了高歌教授，
了解到了他近期从事的一些前沿科研工作的最新进展，尤其是他对龙卷风的研究及其工
程应用价值，让人耳目一新。
高歌教授在采访中提到，传统的航空发动机技术虽然还在不停地改进提高之中，但
受到原理和材料工艺上的限制，已经逐渐逼近了性能发... 阅读全帖 |
|
s*****d
发帖数: 2457 | 50 A startup in ZhangJiang is taking off, having an official launch date on Sep
-1-2015, for the high-speed SERDES market. Detailed job positions are as
below:
https://docs.google.com/document/d/1Rfy5CvXfMf-
4hBl4RxRofy4lcS2gYtDInl8hxA5Qkm0/edit?usp=sharing
======================================================================
ABC Microelectronics, Inc.
We are a Zhang-Jiang stealth-mode semiconductor startup, and have raised VC
money from the world’s leading venture capital firm for hardware. Our
r... 阅读全帖 |
|
