l******u
发帖数: 2314 | 1 正确的名字叫"van Hove singularities"，有简称为vHs。
看我下面的解释时，还是请你拿着一张vHs的图（就是下面说的DOS图）对照着看。
电子谱(electronic density of states, or DOS)本为连续的石墨平面卷成碳管的大小
时，在费米能级(Fermi Level，我把它权当作是能量0点)前后出现一些对称的尖峰 -
因为不连续，所以叫它们singularities。因为van Hove这个牛人于1953年首次发表了
关于类似singularities的文章（当然不是纳米管），所以我们叫这些峰为van Hove
singularities。这种现象不仅仅局限于碳纳米管，而是许多一维固体的通性。
电子谱通常画成“横”的 - 就是碳管的vHs图中那些尖头朝右（不过有时候尖头朝左，
有时候是“竖”的，反正知道是怎么回事就行了）。在尖头朝右的画法下，费米能级（
能量0点）的下面叫做价带(valence band),上面叫做导电带(conduction band)，两边
的vHs峰是对称的。对于搞有机的，可以认为下面就是HOMO，上面就是LUMO。 |
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l******u
发帖数: 2314 | 2 对不起，修正一下：
既然有van Hove singularities，那么那些transitions (S11,S22,M11...)自然就是
van Hove transitions。 |
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s******y
发帖数: 13 | 3 看了这篇paper，不明白van Hove transition 是怎么回事，牛人给普及一下呗。
Chiral selectivity in the charge-transfer bleaching of single-walled carbon-
nanotube spectra
Michael J. O'Connell, Ezra E. Eibergen & Stephen K. Doorn
Nature Materials 4, 412 - 418 (2005) Published online: 10 April 2005
doi:10.1038/nmat1367 |
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发帖数: 1 | 4 Naval History and Heritage Command
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South Dakota I (Armored Cruiser No. 9)
1902... 阅读全帖 |
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c**i
发帖数: 6973 | 5 Of course things can be made by craftsmen, maybe cheaper. But it does not
hurt to have new perspectives.
3D printing is new. Basically a printer receives input from you and lay down
powder of metal or ceramic or plastic (rather than the traditional ink
powder on paper) one layer at a time, which is consolidated by adding glue.
The next layer then starts. The whole process is pretty quick actually.
`````````
Nick Bilton, With 3-D Copier, Print Your Dishes. New York Times, May 16,
2011 (title and ... 阅读全帖 |
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c**i
发帖数: 6973 | 6 Nick Bilton, With 3-D Copier, Print Your Dishes. New York Times, May 16,
2011 (title and date in print)
http://bits.blogs.nytimes.com/2011/05/12/with-help-from-
shapeways-you-can-print-your-dishes/?scp=1&sq=3-d%20printer%20dish%20ceramic
&st=cse
Quote:
"Shapeways, a company that allows people to print 3-D objects, announced on
Thursday that it will now let you print things in a ceramic material that is
'food safe.' Until now, 3-D printers have primarily printed in plastics or
other materials tha... 阅读全帖 |
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z*l
发帖数: 763 | 8 Spanish Ladies
Farewell and adieu unto you Spanish ladies,
Farewell and adieu to you ladies of Spain;
For it's we've received orders for to sail for old England,
But we hope very soon we shall see you again.
Chorus:
We'll rant and we'll roar like true British sailors,
We'll rant and we'll roar across the salt seas,
Until we strike soundings in the Channel of old England,
From Ushant to Scilly is thirty-five leagues.
Then we hove our ship to the wind at sou'-west, my boys,
We hove our ship to our |
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t****z
发帖数: 8931 | 9 500-1000
500 United Kingdom Plymouth 11
501 USA Albany, GA 11
502 USA Corpus Christi, TX 11
503 USA Laurel, MS 11
504 USA Rome, GA 11
505 Spain Ciudad Real 11
506 USA Augusta-Richmond County, GA-SC 11
507 USA Clinton, IA 11
508 USA Klamath Falls, OR 11
509 USA Providence-New Bedford-Fall River, RI-MA 11
510 Canada Bécancour 11
511 Portugal Barreiro 11
512 USA Anderson, IN 11
513 ... 阅读全帖 |
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x****6
发帖数: 4339 | 10 14个学霸开疆辟土，只有一个小黄人：湯川秀樹
1 Founding fathers
1.1 Max Planck
1.2 Albert Einstein
1.3 Arnold Sommerfeld
1.4 Max Born
1.5 Niels Bohr
1.6 Lev Landau
1.7 Hermann von Helmholtz
2 Mayflower branches
2.1 Enrico Fermi
2.2 Friedrich Hasenöhrl
2.3 Eugene Wigner
2.4 Hideki Yukawa
3 Modern European and other branches
3.1 Ralph H. Fowler
3.2 Abdus Salam
3.3 Léon Van Hove
https://en.wikipedia.org/wiki/Academic_genealogy_of_theoretical_physicists |
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s*****n
发帖数: 1998 | 11 http://thebitchywaiter.com/2017/06/waitress-puts-hot-dog-in-her-vagina-befor
e-serving-it.html
Okay, prepare yourselves for the most atrocious act I have ever seen or hear
d of a server doing. Many, many people sent this video to me and I originall
y decided not to share it because, quite frankly, it’s disgusting and I did
n’t want to give the general public any more reason to think that we server
s are lowlife scum bags. However, after seeing how many people had already s
hared it, I figured wh... 阅读全帖 |
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l****z
发帖数: 29846 | 12 尼玛英国要4岁的小孩选择自己的性别:男,女和其他.
你没看错, 还有一个其他的选项可选.
http://www.dailywire.com/news/5345/four-year-olds-being-asked-c
The gender identity obsession has hit full-on insanity in the UK. Children,
as young as four years old, are now being asked to choose the gender they “
most identify with”: male, female, or other. Yes, there was a third option.
Hundreds of parents who signed their children up to attend primary school in
the fall were left furious after receiving informational literature from
Brighton and ... 阅读全帖 |
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c********l
发帖数: 8138 | 13 //MITBBS' article system will mess up the source code
// You may probably need to re-arrange the line breaks
import java.util.ArrayList;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;
public class Solution {
public static void main(String[] args) {
Solution sol = new Solution();
String[] dictStrArr = new String[] {
"dose","ends","dine","jars","prow","soap","guns","hops","
cray","hove","ella","hour","lens","j... 阅读全帖 |
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c********l
发帖数: 8138 | 14 简洁不是最终极的目标，有时候需要reduce runtime complexity
见我之前写的
http://www.mitbbs.com/article/JobHunting/32658475_3.html
//MITBBS' article system will mess up the source code
// You may probably need to re-arrange the line breaks
// by coupondeal@mitbbs
import java.util.ArrayList;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;
public class Solution {
public static void main(String[] args) {
Solution sol = new Solution();
String[] dictStrA... 阅读全帖 |
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x****g
发帖数: 39 | 15 import string
class Solution(object):
def ladderLength(self, beginWord, endWord, wordDict):
"""
:type beginWord: str
:type endWord: str
:type wordDict: Set[str]
:rtype: int
"""
transformation = [beginWord]
wordDict.remove(beginWord)
length = 1
while transformation:
for i in range(len(transformation)):
fromWord = transformation.pop(0)
for i in range(len(fromWord)... 阅读全帖 |
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G****a
发帖数: 10208 | 16 【 以下文字转载自 Parenting 讨论区 】
发信人: lana1972 (lana), 信区: Parenting
标 题: 某个常春藤学校的录取介绍，（很难证明亚裔被歧视），比较乱
发信站: BBS 未名空间站 (Fri Jun 8 16:58:54 2012, 美东)
昨天听了某个常春藤的录取介绍，把能记住的几点分享给大家：
此学校录取率10:1 左右。
1.每个申请阅读时间分布在10几分钟到一小时左右。阅读时间只有10几分钟的不一定被
淘汰。
2.BLIND admission, need-based 奖学金。录取的时候不看财政情况，录取后根据家庭
财政决定学生和家庭的负担。家庭特穷60000一下一切费用全免，收入160000 万以上基
本不要想着从学校得到帮助。在校打工是对学生的一种帮助。家庭财务状况会被翻个底
朝天，包括父母退休账户。
3.对中低收入的家庭去学费低的学校可能会花更多的钱，因为学校相应的各种财政帮助
也少的可怜。
4.Diversity 是考虑因素之一，族裔不言而喻在考虑因素之内。偶的观察有些族裔的学
生表现真的是生拉硬拽。应该是录取的时候刻意考虑了... 阅读全帖 |
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c*h
发帖数: 33018 | 17 【 以下文字转载自 Parenting 讨论区 】
发信人: lana1972 (lana), 信区: Parenting
标 题: 某个常春藤学校的录取介绍，（很难证明亚裔被歧视），比较乱
发信站: BBS 未名空间站 (Fri Jun 8 16:58:54 2012, 美东)
昨天听了某个常春藤的录取介绍，把能记住的几点分享给大家：
此学校录取率10:1 左右。
1.每个申请阅读时间分布在10几分钟到一小时左右。阅读时间只有10几分钟的不一定被
淘汰。
2.BLIND admission, need-based 奖学金。录取的时候不看财政情况，录取后根据家庭
财政决定学生和家庭的负担。家庭特穷60000一下一切费用全免，收入160000 万以上基
本不要想着从学校得到帮助。在校打工是对学生的一种帮助。家庭财务状况会被翻个底
朝天，包括父母退休账户。
3.对中低收入的家庭去学费低的学校可能会花更多的钱，因为学校相应的各种财政帮助
也少的可怜。
4.Diversity 是考虑因素之一，族裔不言而喻在考虑因素之内。偶的观察有些族裔的学
生表现真的是生拉硬拽。应该是录取的时候刻意考虑了... 阅读全帖 |
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H****w
发帖数: 1632 | 18 Billy Walter and the computer group:
The Arrests
He was in the bed sleeping when the two men walked into his bedroom.
Billy
Walters sleeps in a big clean bed in Las Vegas, in a small but elaborate
home renovated to his liking, with palm trees and white flowerpots and
two
satellite dishes in the yard, and four large televisions in the den, and
a
security guard who sits just out of sight behind the shrubs across the
street. This environment was disrupted early last Jan. 5, when the two
strangers i... 阅读全帖 |
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p*********3
发帖数: 2039 | 19 http://en.wikipedia.org/wiki/Nurse_with_Wound_list
Agitation Free, German rock group.
Pekka Airaksinen, Finnish musician and member of the group Sperm (see below).
Airway, project of Joe Potts as part of the Los Angeles Free Music Society
collective.
Albrecht/d. German artist with ties to the Fluxus scene. He has worked with
Joseph Beuys and Throbbing Gristle (see below).
Alcatraz, German rock group.
Älgarnas Trädgård, Swedish rock group.
All 7-70, see Ritual All 770 (below)
Alter... 阅读全帖 |
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b******5
发帖数: 1415 | 20 Sorry. No one hoves Hanhan here. But here everyone know Fang is shit.
Why do you think people who know Fang is shit have to love Han. |
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c*******r
发帖数: 3289 | 21 hoving board刚试飞,能飞270米,不错了! |
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m***y
发帖数: 14763 | 22 马克吐温
这个奴隶主遗少转弯抹角的攻击南方新生革命政权，为奴隶经济搽脂抹粉。
在他笔下，奴隶和奴隶主亲如一家，打情骂俏，完全丧失了基本的阶级立场。
Jim came skipping out at the gate with a tin pail, and singing Buffalo Gals.
Bringing water from the town pump had always been hateful work in Tom’s
eyes, before, but now White, mulatto, and negro boys and girls were always
there waiting their turns, resting, trading playthings, quarrelling,
fighting, skylarking. And he remembered that although the pump was only a
hundred and fifty yards off, Jim never got back with a buck... 阅读全帖 |
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G*******s
发帖数: 4956 | 23 今天我们创世纪的查经要与你分享：
《三个世界》
经文：创1:1,2
《创世记》
1：1
起初 神创造天地。
《创世记》
1：2
地是空虚混沌，渊面黑暗； 神的灵运行在水面上。
《创世记》
1：3
神说：“要有光。”就有了光。
《创世记》
1：4
神看光是好的，就把光暗分开了。
《创世记》
1：5
神称光为昼，称暗为夜。有晚上，有早晨，这是头一日。
·1:1——原文为7个字，是全本圣经的基础，骨干
·起初：指历史时间的开始。在他之前，除上帝之外，万物都不存在，此处为绝对的起
初，绝对的开始，而非年代。
·起初——末后连在一起。暗示宇宙既有开始，就会有末后和结束。
·神——全本圣经的主角
在神创造万物之先，先造了一样，大家知道是什么吗？
·时间被造（1）──“起初”乃表明了历史时间的开始，即是说“时间”亦是同时被
造的，而神自己则没有被空间和时间所限制，因祂是永生的神，祂过去和将来是永远存
在的，直到无终的万代。
所以天地乃是空间，而起初乃是时间，时空均为上帝所创造！
·1:2 地——指大地。人所居住的地方。
第一节的宇宙之后焦点集中到至人类所居的地... 阅读全帖 |
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x********8
发帖数: 167 | 27 关于vHs的推导和介绍可以进一步参阅charles kittel 著的introduction to solid
state physics。见528页。当然老豆腐已经把基本概念说的很清楚了，这个vHs是一维
纳米材料的能带特征。 |
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f********e
发帖数: 40 | 29 好像 vHs能量间隙有点不对吧。我怎么记得是M11=3S11, S33=4S11,M22=2M11 |
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d*******l
发帖数: 2567 | 30 单个ＣＮＴ一般不是，不有Van Hove singularities么？但是长成ＣＮＴ森林就不一样
了，有可能吸收谱变宽，吸收系数变大，趋近于１，较理想的黑体了。 |
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b*p
发帖数: 242 | 31 不仅仅是flapping wing，hummingbird可以hoving又可以~25mph normal flight和60
mph diving。
某中意义上说是很厉害的飞行器。。。 |
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y********a
发帖数: 397 | 32 Scared, too bloody le! TP's soul is hoveing in the air staring at you! |
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v*******e
发帖数: 3714 | 33 The next time I saw Douglas was in November, 1944. He had recently come out
of a nursing home, where he had spent four weeks in bed undergoing a rest
cure, and was now in lodgings at Hove. 'I am miserably ill with a bad heart
(leaky valve)', he wrote to
me, adding that he did not expect to recover at the age of seventy-four, his
heart being worn out after all his troubles and fights. Nevertheless 'I can
still talk' he assured me, and invited me to visit him, when he would tell me
everything I wa |
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