x*d
发帖数: 1696 | 1 手柄的形状是除了重量重心对我影响最大的。老肯你是专家，我想问一下是不是每个牌
子的手柄形状是一致的，也就是不同型号的形状基本一样。如果是一致或者比较一致的
，你知道那个参数吗? 比如说每边之间的长度比例和夹角，或者到哪里能查到Template.
我本来有意买那个打折的Boris Becker拍子，但后来看到手柄好像是接近四方的，放弃
了。
还有个问题：
If you compare the following two rackets, same size, length, balance, beam
width, almost same weight. But why is there a huge difference for
Swingweight?
-----------------------------
Boris Becker Delta Core Melbourne
Head Size:
98 sq. in. / 632.26 sq. cm.
Length: 27in / 69cm
Strung Weight: 12oz / 340g
Balance: 6 pts HL
... 阅读全帖 |
|
f*********a
发帖数: 18 | 2 重新捡起网球半年多了，一直在用walmart的大头拍跟公园里的成人班。
最近悲催的发现拍子的拍柄好像买大了，特别是缠了一圈胶布之后，打久了虎口有
些疼。然后练习volley时感觉拍子头重脚轻，拍面经常歪。于是动了换个拍子念头。
第一个拍子是一姐们电话里墙裂推荐的，可惜和我不在一个城市，不能拿她的试，
100的拍面不确定习不习惯：
Prince EXO3 Hornet Midplus 100 $79.95
Head Size: 100 sq. in.
Length: 27in
Strung Weight: 10.3oz / 292g
Balance: 3 pts HH
Swingweight: 313
Stiffness: 65
Beam Width: 23.5mm / 25mm / 23mm /
Power Level: Medium-High
Stroke Style: Medium-Full
Swing ... 阅读全帖 |
|
f*****n
发帖数: 18176 | 3 It's official, this will be the name of the Federer racket, it will come in
three different specs as listed below. Release date 10/1/14.
Pro Staff RF97 Autograph:
340g/12oz Unstrung
22mm beam
16x19
ProStaff 97
11.1oz unstrung
22mm beam
16x19
ProStaff 97 LS
10.2oz unstrung
23mm beam
16x18
You're welcome!! |
|
b*********s
发帖数: 6757 | 4 我搞错了， 我把beam thickness 误认为是beam width了。 我喜欢beam thick 一点的
frame. |
|
b*********s
发帖数: 6757 | 5 我搞错了， 我把beam thickness 误认为是beam width了。 我喜欢beam thick 一点的
frame. |
|
b*********s
发帖数: 6757 | 6 Volkl c10 pro 98 beam is only 20mm thus you mean feel lack the power. It has
a very fast swing though which compensate the lack of power from the
racquet itself. And because of the thinner beam it is very easy to maneuver.
It's one of the classic.
The one I tried is Super G10 325, similar beam but much thicker. It still
will be a very different feel compare to prestige though. I tried migrocel
prestige 18x20 before, slice is super good, but not much power, the feel is
similar to the wilson 6.1 9... 阅读全帖 |
|
b***u
发帖数: 12010 | 7 http://half-life.wikia.com/wiki/Aperture_Science
Aperture Science, Inc.,[7] often simply referred to as Aperture Science or
simply Aperture, is an American scientific research corporation whose
laboratories and administration, Aperture Laboratories, are located in
Cleveland, Ohio, USA.[1] Originally a shower curtain manufacturer, it
evolved over the course of half a century into an experimental physics
research institution and a bitter rival of Black Mesa.
"Aperture Laboratories" is also used as... 阅读全帖 |
|
a*****a
发帖数: 2755 | 8 转载请注明“susanmiller小组”及译者很多圈，谢谢！
译者：很多圈
来自：susanmiller小组（http://www.douban.com/group/susanmiller/）
亲爱的射手，你将会爱上九月这个充满着力量，和友好的月份的。它将会给你一个卓越
的工作机会来使你的工作迈出关键的一步！当然也会有除了事业以外的其他事情写入你
9月的篇章里，但是在这个月，请将事业放在第一位。在好的推动力下，现在，你拥有
着的可是一个千金难买的机会来让你在事业上有重大的飞跃，所以请在这一整个月里都
保持你在事业上的注意力。
9月5日，新月来临的那一刻，你将会听到一些新的好消息。所有的新月，满月，月食，
和其他星象，影响着你过去的行为，和你所做的决定，以及你所付出的表现。你过去工
作的越努力，越智慧得工作，现在你所能获得的奖赏就越多。这就是占星学——它并不
是能决定你未来的先知。星座能够帮助到你的是，当你的行为对未来有影响，而这个影
响将会给你一个成功的机会的时候，它便提醒你，并让你发现它。这个月你在事业上将
会得到的进步和发展，是非常难得的。
这次的新月将会从木星那里得到带来的金融上... 阅读全帖 |
|
wh
发帖数: 141625 | 9 好玩！这个片子有没有原著？要是有你肯定也会翻是不是？哈哈。求电子羊签名本……
看到豆瓣有卖电子书。blade runner以前pqwer和bos聊起过，我转到scifi版过。pqwer
引用的那段中文是你的原版吗：
发信人: wh (wh), 信区: SciFiction
标 题: 转一个《The Blade Runner》的结尾描写
发信站: BBS 未名空间站 (Thu Feb 17 16:44:10 2011, 美东)
发信人: pqwer (例如), 信区: LeisureTime
标 题: Re: 关于读过的几本书
发信站: BBS 未名空间站 (Wed Feb 16 19:23:57 2011, 美东)
This sounds familiar.
The final scene in blade runner:
"I've seen things you people wouldn't believe. Attack ships on fire off the
shoulder of Orion. I watched c-beams glitter in the da... 阅读全帖 |
|
r*****j
发帖数: 7481 | 10 今天把subfloor给锯开了一个口子，
然后揭开，发现地基是concrete slab, 然后beam是steel beam的。
接着把garage的一面内墙也拆了，发现墙是Inverted-V-Braced。（不过我感觉这个焊
接不是很靠谱，不过不是high rise structure，应该不用担心所谓的period和
buckling了）
garage顶棚的beam也都是 steel frame。 |
|
G**Y
发帖数: 33224 | 11 看了一下，左右headlights都有fuse。即使fuse坏了也不会左右一起黑。
很可能是第一个坏了一段时间，但是我一直没发现。现在第二个坏了？
low beam坏了，high beam还能使，但也不能high beam上街呀。
明天去shop吧。我们穷乡僻壤，连个walmart都没有，还是不自己折腾了。 |
|
t******2
发帖数: 42 | 12 有人用roku twonky吗？ 周末搞了半天发现twonkey beam只可以看qq视频。 有人知
道twonky 还支持哪些其他中文视频网站吗？
顺便稍微介绍一下twonky
在roku上添加频道‘mytwonky’，手机上下载twonkey beam应用后，就可以通过手机把
视频streaming到电视上。twonky beam应用自带一些视频网站，个人感觉就youtube还
有点用 剩下的看的不多。 |
|
e******o
发帖数: 140 | 13 twonky 根本beam不了 显示unable to beam this media is not supported or may be
invaild.有时候beam YouTube的一些视频也显示这个 这是为啥啊 还有别的方法可
以看优酷么 |
|
m*********n
发帖数: 11525 | 14 ☆─────────────────────────────────────☆
HDStreamer (HDStreamer) 于 提到:
三个我都用过一段时间。对我个人而言，My Plex最适合。
Plex本身是从服务器和本地资源播放做起。它有其他这儿没提到的功能。但使用也相应
更复杂些。近年来网络资源播放日渐受欢迎。就象Twonky 加了 Twonky beam一样。
Plex也针对网络资源加了My Plex。
我这儿把过程简化一下，只针对在网上看中文电视。这种情况下，可以相当简单：
1.不用安装任何服务器。
2.不需有个电脑在ROKU附近，甚至连电脑和ROKU在同一个网络的需求也不要；可以在任
何一个电脑上操作。
3.无需在手机上下载APP，也无需用到手机， 因而不会浪费手机的电，也可以一边看电
视，一边用手机上网（Twonky Beam 需要手机一直传送数据给ROKU，否则看一半电视老
断掉）
4.可以自己根据自己网络速度控制图像质量（网星分免费的标清和收费的超清，每类中
图像质量也是由网主，天线宝宝，定。Chromecast 和手机，DVD机上的APP都采用自动... 阅读全帖 |
|
d*********e
发帖数: 1918 | 15 看来你是在那里凭空想象。你以为机器人就站在那里跟靶子似的等你所谓的高能粒子击
穿？集成电路又不直接长时间地exposure在beam 之下。退一步，假设就算像你说的，
机器人被beam照射了，集成电路在机器人里面，外面还有金属壳cover，你可以算一算
在某高能情况下，外面的金属壳所用材料的吸收长度是多少。beam基本上不可能穿透那
么厚的外壳再 击穿集成电路的。 |
|
u******a
发帖数: 7843 | 16 国内司机的驾驶素质确实比较低下. 典型的例子是大部分司机永远是开high beam的,
即使会车的时候也不会切成low beam. 大概和执法力度也有关, 在美国你开high beam
早就被开罚单了, 在中国不罚...感觉在教育司机的问题上, 开罚单可以解决很多问题.
.. |
|
u******a
发帖数: 7843 | 17 国内司机的驾驶素质确实比较低下. 典型的例子是大部分司机永远是开high beam的,
即使会车的时候也不会切成low beam. 大概和执法力度也有关, 在美国你开high beam
早就被开罚单了, 在中国不罚...感觉在教育司机的问题上, 开罚单可以解决很多问题.
.. |
|
S*********g
发帖数: 24893 | 18 【 以下文字转载自 Stock 讨论区 】
发信人: StephenKing (金博士), 信区: Stock
标 题: 向民族英雄包鹏程致敬！为民族英雄包鹏程欢呼！
发信站: BBS 未名空间站 (Wed Jun 3 20:54:21 2015, 美东)
Pengcheng Bao, Graduate Student
Pengcheng is a second year graduate student. He obtained his B.S. in physics
from Nankai Univeristy in China.
Project: Development of methodology for realistic modeling of heterogeneous
catalytic interfaces.
Tel: 310-206-3215
Email: [email protected]
/* */
PENGCHENG BAO
Education
and Awards
2009 –
NANKAI UNIVERSITY TIANJIN, CHINA... 阅读全帖 |
|
m***y
发帖数: 14763 | 19 "So frequently do trucks crash into the 11-foot-8 clearance trestle, that
the railroad company installed a crash beam in front of it. This massive
steel I-beam bears the brunt of the impact, protecting the structure that
supports this fairly busy railroad track. Believe it or not - they already
had to replace the beam once! "
Come on, the bridge would have been rebuilt if it were in China. |
|
w*****9
发帖数: 2193 | 20 more brighter 是个语法错误，呵呵，只要brighter就可以了。
The majestic glacier glows the moonlit beam里面的glow是不及物动词，后面不能
跟名词。reflects适用，不过音节可能不合。另外moonlit beam应该是moonlight beam
吧，moonlit是指月光照到的地方。 |
|
D*****r
发帖数: 6791 | 21 http://www.gutenberg.org/files/37726/37726-h/37726-h.htm
IN GOD'S WAY
SCHOOL-DAYS
I.
In the melting snow on the hill-side by the sea, in the last rays of the
evening sun, stood a boy of fourteen, awestruck. He looked toward the west,
out across the sea; he looked toward the east, over town and shore and the
broad hills; in the background still higher peaks rose far away in the clear
sky.
The storm had lasted a long time; it had been more terrible, too, than any
the old people could remember. In ... 阅读全帖 |
|
g*****g
发帖数: 34805 | 22 先弄明白C是怎么回事吧。
beam += y + icm[y].offset 这种无非是移动指针，
你只要设一个index
index = y + icm[y].offset
后面*beam = .. 的时候你做beam[index]=.. 就可以了。 |
|
l**n
发帖数: 109 | 23 micro beam 打不出来的一个可能是根本没打到晶体上，因为你看不到晶体
如果solvent够薄，beam和晶体差不多大，beam足够强，而且真正打在了晶体上，还是
有希望达到足够被检查到的信噪比 |
|
e**r
发帖数: 1144 | 24 Cell Motil Cytoskeleton. 1994;27(3):262-71.
Cellular infrared detector appears to be contained in the centrosome.
Albrecht-Buehler G.
Source
Department of Cell, Molecular, and Structural Biology, Northwestern
University Medical School, Chicago, Illinois 60611.
Abstract
Previous experiments have suggested that 3T3 cells were able to extend
pseudopodia toward latex particles up to 60 microns away from the cell body
if the particles were irradiated by an infrared beam in the range of 700-900
nm [Al... 阅读全帖 |
|
l**********1
发帖数: 5204 | 25 Please refer:
scanned Bessel beams in conjunction
with structured illumination and/or two-photon excitation to create thinner
light sheets (<0.5 μm) better suited to three-dimensional (3D) subcellular
imaging
PubMed link:
//www.ncbi.nlm.nih.gov/pubmed/21378978
Planchon TA, Gao L, et al.
Rapid three-dimensional isotropic imaging of living cells using Bessel beam
plane illumination.
Nat Methods. 2011 May;8(5):417-
>Abstract
>A key challenge when imaging living cells is how to noninvasively extract... 阅读全帖 |
|
l**********1
发帖数: 5204 | 26 Zhuang XW STORM Stochastic Optical Reconstruction Microscopy
//www.nature.com/nmeth/journal/v5/n12/full/nmeth.1274.html
borrowed basic mathematic principle from 蒙特卡洛法:
below novel “Three body” noted that ball is laser they used in STORM
球越小结果越精确。
//zh.wikipedia.org/wiki/中微子
New speed of light... or was it just a dodgy cable? Scientists at Cern believe results were skewed
UPDATED: 07:54 GMT, 24 February 2012
//www.dailymail.co.uk/sciencetech/article-2105353/Faulty-wires-CERN-test-results-debunk... 阅读全帖 |
|
A*******l
发帖数: 67 | 27 我们用Varian比较多
现在用的都是100和300系列
优点是stability, sensitivity,reproducibility
官方的baseline stability是0.0003 abs/hr,我实测到新的机器可以到0.0001abs/hr，
多次重复一致
缺点是维修比较贵，由于典型的double beam设计，旧仪器chopper元件的故障率很高，
基本上两三年要换一次，当然也是因为我们用的assay比较intense，经常7X20的用
一直很想买他家的50/60系列，但是老板不批钱
50/60系列的优点是速度和方便
像楼上讲的Agilent一样，可以开室测试。因为使用功率非常高的Xenon lamp，而不是
普通的UV/vis lamp，所以室内光源对测试基本没影响。而且由于Xenon lamp直接覆盖
190-1200nm，没有通常所见的uv/vis光源切换造成的spike。这个系列使用dual beam设
计，没有chopper元件，所以故障率比较低。缺点是理论上来讲没有double beam的
stability和reproducibility好，但实测几... 阅读全帖 |
|
a*******l
发帖数: 2353 | 28 Beam to column connection
Shear only connection
Double angle on beam web.
Bolted on both beam web and column flange.
设计bolts只考虑剪力,因为梁翼板没有和柱焊接不能形成有效的力矩.
但是,通常我们说shear only,简支梁端的连接,基本上free of rotation.
考虑极端情况,角钢长度和梁深一样,根据设计可以只用两个bolt,上下各一个关于中性
轴对称, 如何free rotation? 如果不能自由转动,岂不是可以承担弯矩,可以承担多少
? 最大为梁腹板屈服?
LRFD设计验算Shear, Bearing, Block shear (shear rupture)中,哪一项包含了上述内
容?
我是不是想得太奇怪了. |
|
n**********b
发帖数: 114 | 29 No.
The rotation is proportional to the moment and depends on the stiffnes of
that section. Normally without the displacement between shear tab and beam
web, the rotation is very tiny. When the moment is larger than the capacity
of that pin connection, the bolts or the shear tabs or the beam web might
fail. And it is a little complicated and depends on the beam section.
wheel (Would you hold still ? Please) 的大作中提到: 】 |
|
n**********b
发帖数: 114 | 30 When you design shear wall buildings, the column and beams (except link
beams between shear walls) should be considered only under gravity load. So
if you design columns and beams under the lateral load, you will get a wrong
reinforcement plan. Or if you shear walls is very small relative to the
columns, you may consider the building as a combined frame and shear wall
building, which is called bearing walls building in ACI318-08 (I may be not
correct about this since my ACI is in the office.) |
|
r*****j
发帖数: 7481 | 31 living room 到 kitchen 的big open space只有一个LVL beam。
其他地方没有beam or continuous beam.
一楼只有bearing wall。 |
|
z******i
发帖数: 5114 | 32 I found this while I am reading ACI 209:
Although creep and shrinkage effects may be higher in
thin slabs than in beams (time-dependent deflections as
large as 5 to 7 times the initial deflections have been
noted,2g*3g the same approach for predicting timedependent
beam deflections may, in most cases, be used
with caution for flat plates and two-way slabs. These
include Eqs. (3-7), (3-8), and (3-10) for the effect of
compression steel, etc., and Eq. (4-3) for additional
long-time deflections. Th... 阅读全帖 |
|
f*****k
发帖数: 195 | 33 我的micro fabrication 的流程：
clean glass
e-beam deposit Ti 15nm on glass
e-beam deposit Au 150nm on top of Ti
spin coating photoresist on Au
develop 4 micro structures
wet etching Au and Ti
这样做出来的micro structure 一加电压Au就peel off了， 为什么呢？
我看了文献，看很多人用sputtering 镀膜 而不是 e-beam，然后 lift off 而不是wet
etching。他们那样做出来的micro structure 好像很robust。
不知道是不是我的流程有问题呢？ |
|
c******k
发帖数: 1140 | 34 老板给了我一个idea, 我们实验室有台皮秒超短脉冲激光光源，接个1x2 beam
splitter,一路接那个板子上的光纤，再找一个1x2 beam splitter，实际上当作2x1
beam combiner, splitter跟 combiner对接后，combiner的那个输出接个高速光
detector,最后连接示波器。想法估计上测量这两路脉冲之间的时延。然后计算光纤长度
刚做完这个试验，发现超短脉冲激光光源是36MHz的重复频率，结果在示波器显示的是
36MHz的电脉冲信号，根本找不到或者分不清有板子那路还是没板子那路？ |
|
c*u
发帖数: 916 | 35 这种东西如果你不用干涉仪，直接电测量即使弄出来也是不准确的。除非你有GHZ的
detection.
既然有picosecond的光源，这个貌似很容易，
皮秒超短脉冲激光光源，接个1x2 beam splitter,一路接那个板子上的光纤，另一路接
一段大约10米的光纤，你不是估计这段光纤大概10几米左右么，就接一段比它短一些的
光纤，然后弄个variable length delay line，比如fiber launcher + mirrors，然后
再找一个1x2 beam splitter，实际上当作2x1 beam combiner, 其实就是弄个mach-
zender interferometer。
如果你有picosecond的光源，一ps相当于几毫米，所以这么搞，你的精度可以达到毫米级
长度 |
|
m*******e
发帖数: 639 | 36 Sorry that I can't input Chinese at work.
Electron beam widths can get down to a few nm, while the resolution is
generally determined by the forward scattering in the photoresist.
If you are really interested in this topic, you can do a brief "google"
research on "e-beam" and "ion beam" lithography. |
|
l*****o
发帖数: 82 | 37 Thanks for your explaination.
My polymer is PMMA, a very popular photo resist in electron beam
lithography. The film was stored in clean room with a pretty
constant physical/ chemical environment.
The image shows the polymer lines get fatter. But I have no idea
whether it's due to the immigration of Au/Pd or PMMA itself.
I can only say, e-beam energy deposition of SEM scanning can broke
the bonds of PMMA. But it's not a glass transition.
Although someone report e-beam energy may have heat effect |
|
f*******r
发帖数: 204 | 38 Warping means distorsion of cross-section in the third direction (i.e. the
axial direction of a beam). This generally happens in torsion of thin-walled
beams, for example the I-shaped beams.
You can check the definition in the theory of plates and shells, expecially
in the chapter talking about torsion. |
|
S*M
发帖数: 104 | 39 Hi there,
Sorry for bothering. I have a question about E-beam heating on STM machine.
We currently plan to use E-beam heating at the machine but it seems like the
machine has only radiative heating function. Now we need to modify the
power supply and filament a little bit to realize E-beam heating. The way is
to float the current power supply and bias the filament. Does anyone have
relative experience before? It will be perfect if you also use Omicron's
STM or Delta's power supply. Thanks a lot |
|
S*M
发帖数: 104 | 40 【 以下文字转载自 NanoST 讨论区 】
发信人: STM (STM), 信区: NanoST
标 题: floating power supply
发信站: BBS 未名空间站 (Mon Jul 2 11:05:23 2007)
Hi there,
Sorry for bothering. I have a question about E-beam heating on STM machine.
We currently plan to use E-beam heating at the machine but it seems like the
machine has only radiative heating function. Now we need to modify the
power supply and filament a little bit to realize E-beam heating. The way is
to float the current power supply and bias the filament. Does anyone |
|
r******l
发帖数: 121 | 41 Now I see what the problem is.
The definition of NA = lambda_0/(n*D) is the NA of a Gaussian beam. In
common situations of focusing, we do not treat the beam as Gaussian beam but
a plan wave truncated by the aperture of the lens. In this way, the full
aperture of the lens is used and then one can achieve minimum focus spot
size. The spot size in the plane-wave incidence case is determined by the
Fourier transform relation (ref: Introduction to Fourier Optics, J.W.Goodman
).
If your situations is |
|
r******l
发帖数: 121 | 42 Almost no universal solution for sure, and I do not see why Fourier Optics
should work.
A couple of thoughts that you may want to consider:
1. When your sample is thick enough, you can use a beam with small beam size
so the reflected beam at two surfaces will not overlap spatially.
2. When you can use confocal geometry, choose the focus right at the bottom
surface, and use an small aperture at the image plane. In this way, most of
the light reflected by the first surface will be blocked by the a |
|
j*******d
发帖数: 142 | 43 Nevel doubt the energy conservation. In order to combine two beams, you must
use a beamsplitter. Because the reflection is out-of-phase with the
incident beam (half-wave loss), if on one side of the BS the two waves are
in phase, then they must be out-of-phase on the other side. The total energy
is always the sum of the two laser beams, but how does the energy
distribution between both sides depends on the relative phase. |
|
c**i
发帖数: 6973 | 44 US Achieves Breakthroughs in Laser Weaponization
发信站: BBS 未名空间站 (Fri Apr 15 15:03:18 2011, 美东)
William Lawther, US Laser Could Fend off PRC Boats. Taipei Times, Apr 16,
2011 (available now).
http://www.taipeitimes.com/News/taiwan
/archives/2011/04/16/2003500888
Quote:
"Just three months ago, the US Office of Naval Research issued a statement
saying that scientists at Los Alamos National Laboratory, New Mexico, had
perfected a way to generate megawatt laser beams. When developed into a
weapon, th... 阅读全帖 |
|
c*******9
发帖数: 9032 | 45 Summation of Tesla's Dynamic Theory of Gravity
An excerpt from: Occult Ether Physics
by William R. Lyne
From: Don Allen
d**[email protected]
According to Tesla's lecture prepared for the Institute of Immigrant Welfare
(May. 12, 1938), his "Dynamic Theory of Gravity" was one of two far
reaching discoveries, which he "...worked out in all details", in the years
1893 and 1894. The 1938 lecture was less than five years before his death.
More complete statements concerning these discoveries can ... 阅读全帖 |
|
T**E
发帖数: 1892 | 46 Neutrino experiment affirms faster-than-light claim - November 18, 2011
An updated version of this story is now available (see 'Neutrino experiment
replicates faster-than-light finding').
It is a remarkable confirmation of a stunning result; but most physicists
remain skeptical. That seems the most probable outcome of a release of new
data expected on 17 November from researchers with the Italian OPERA
collaboration, who say they have confirmed their controversial finding that
flighty subatomic ... 阅读全帖 |
|
p*****r
发帖数: 805 | 47 帮我国内的亲戚问的，他博士做的是同步辐射加速器束流位置的研究还有高能物理实验
（如粒子对撞机及空间粒子探测）电子读出学的研究，主要就是处理探测器输出的电信
号，医疗仪器方面的电子学研究也比较对口，具体学校和专业他没有什么特定的。中科
大博士即将毕业，曾经和Hawaii University 和BEPC National Laboratory有过交流合
作，希望来美国做博士后，请问什么样的学校或者实验室会有可能有机会？他的
publication如下：
"A charge measurement method of readout electronics for BES Ⅲ TOF detector"
, Nuclear Science and Techniques， 2009.
"Design of the Fully Digital Beam Position Monitor for Beam Position
Measurement in SSRF", The Ninth International Conference on Electronic
Measurement & In... 阅读全帖 |
|
S*********k
发帖数: 507 | 48 From today's NY Times:
Tingye Li （厉鼎毅）, Instrumental in the Laser’s Development, Dies at 81
Tingye Li, an electrical engineer whose calculations in the early 1960s
helped guide the development of the laser and propel the dizzying increase
in the speed of fiber-optic communication, died on Dec. 27 in Snowbird, Utah
. He was 81.
Family photo
Some of the work done by Dr. Tingye Li and his colleagues at Bell Labs laid
the groundwork for today’s broadband.
The cause was a heart attack while he was on... 阅读全帖 |
|
p******e
发帖数: 58 | 49 As far as I understand, the super long tunnle is not necessary.
As I mentioned before, some accelerater experiments are under consideration.
The one you mentioned might be one of them. They are usually have the
following setting.
1. Produce neutrino beam on an accelerater. In the case you mentioned, it
is likely that the beam is produced at Fermilab in Chicago.
2. Direct the beam to a target detector far away. So Minnesota might be
the place where the detector sits.
The reason for no tunnle n |
|
k***a
发帖数: 92 | 50 Found a new paper on this subject: PRL 89, 093004
Here is the abstract:
A neutral polar molecule experiences a force in an inhomogeneous electric
field. This electric field can be designed such that a beam of polar molecules
is exposed to a harmonic potential in the forward direction. In this potential
the longitudinal phase-space distribution of the ensemble of molecules is
rotated uniformly. This property is used to longitudinally focus a pulsed
beam of ammonia molecules and to produce a beam |
|
