d********y
发帖数: 176 | 1 多谢！
http://iopscience.iop.org/article/10.1088/0022-3719/18/6/008/pdf
Journal of Physics C: Solid State Physics
Low- and very-low-frequency dynamics in ZnCl2 aqueous solutions: a
comparative investigation by Raman, Rayleigh wing and inelastic neutron
scattering
G Maisano, P Migliardo, M P Fontana, M -C Bellissent-Funel and A J Dianoux
Journal of Physics C: Solid State Physics, Volume 18, Number 6 |
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d********y
发帖数: 176 | 2 多谢！
http://iopscience.iop.org/article/10.1088/0022-3719/18/6/008/pdf
Journal of Physics C: Solid State Physics
Low- and very-low-frequency dynamics in ZnCl2 aqueous solutions: a
comparative investigation by Raman, Rayleigh wing and inelastic neutron
scattering
G Maisano, P Migliardo, M P Fontana, M -C Bellissent-Funel and A J Dianoux
Journal of Physics C: Solid State Physics, Volume 18, Number 6 |
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j**u
发帖数: 6059 | 3 ☆─────────────────────────────────────☆
pinacle (大石头) 于 (Tue Apr 22 15:06:20 2008) 提到:
名校如何定义的？RPI还是不错的
in
of
at
Source
neutron
as
,
☆─────────────────────────────────────☆
billyLi (billy) 于 (Tue Apr 22 20:39:11 2008) 提到:
RPI is a decent school, especially considering its reputation in your field. BTW, i
am going to that school too.
☆─────────────────────────────────────☆
hawaiiouqd (hawaii) 于 (Tue Apr 22 20:49:47 2008) 提到:
你是没说老板是谁，但是信息都登出来了，和说了是谁有什么区别？
☆─────────────────────── |
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y******3
发帖数: 311 | 4 帮朋友找的，两个职位，都在加州Santa Clara。前一个职位要求高一些，第二个职位
有相关工作经验就行 W2 $170-180k per year and no relocation package，long
term contract
job description:
Cloud Architect
Exp with developing, building and operating sophisticated and highly
automated Cloud infrastructure (AWS, Docker, Openstack, VMWare, or Rackspace
) a must.
·Prior success in automating a real-world production environment a must.
·Familiarity with AWS CloudFormation, Opswork, Elastic Beanstalk, Code
Deploy/, Pipeline/Commit, Openstack Heat, Clo... 阅读全帖 |
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n********e
发帖数: 133 | 5 这位老师很nice,所以帮忙转贴一下。
下面是教授的研究方向和招学生的简介。希望申请者有计算（simulation）的背景，
可以是工物系，机械系，力学系或者相关专业毕业的。希望能2010年春季入学，fall
也可以。
研究可应用于核电，医疗器械等等不错的行业中。
Research Interests:
..
Monte Carlo modeling and simulation in radiation particle (photon/electron
/neutron) transport computations
..
Methodology and code development for radiation transport in highly
heterogeneous
media and its applications to medical physics and reactor core analysis
..
Advanced reactors (Gen IV designs such as Very High Temperature Gas-cooled
Re |
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w********h
发帖数: 12367 | 6 Pierre-Gilles de Gennes
P. G. de Gennes was born in Paris, France, in 1932. He majored from the
École Normale in 1955. From 1955 to 1959, he was a research engineer at
the Atomic Energy Center (Saclay), working mainly on neutron scattering and
magnetism, with advice from A. Herpin, A. Abragam and J. Friedel (PhD 1957).
During 1959 he was a postdoctoral visitor with C. Kittel at Berkeley, and then
served for 27 months in the French Navy. In 1961, he became assistant
professor in Orsay and |
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w********h
发帖数: 12367 | 7
计算.
Generally obtained using SANS (Small Angle Neutron Scattering).
you can refer to those two Fetters' papers |
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d*****s
发帖数: 313 | 8 I think you need to have a basic idea of what kind of material you
have then you get a model yourself. |
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t**r
发帖数: 5 | 10 I use Parratt32 to fit the data. Let's exchange some experience
呀? |
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c*****e
发帖数: 238 | 11 都是关于theory的
Modern Theory of Polymer Solutions
by M. Yamakawa
此书是经典之一,现在好像作者修订之后有了电子版,大家可以去搜一搜.
除此之外
polymers in solution: their modelling and structure
by G. Jannick and des Cloizeaux
这是非常comprehensive的书,两个作者一个是Neutron Scattering的专家,一个是
renormalization group的专家, de Gennes开创性的工作是和des Cloizeaux合作
一些的.可以参见他1972年的那篇phys. lett.
不过此书非常贵而且typo很多,关键是买不到
建议去看看法文版(原版,英文是翻译的), les polymeres en solutions
好像可以定购
最后是renormalization group of macromolecules,by Karl Freed
此书我从来没见过,不过my advisor是Freed的学生,说此书"过于重视 |
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z**h
发帖数: 224 | 12 neutron scattering
factor的,在spinodal附近确实有peak
定
transition,
. |
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c*****e
发帖数: 238 | 13 I think dynamic/static light scattering is used for determination of the
structure factor for density fluctuation in phase transitions,
usually at the length scale of the wavelength of light.
X-ray scattering is used to determine the crystal lattice constants.
Neutron scattering could be used to determine the correlation functions of
deutrium, mostly used to characterize the conformation of a single chain,
what I know about SANS is it can be used to measure Rg. |
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z**h
发帖数: 224 | 14 nuetron reflecticity can measure the lamellae spacing.
the length between 10A and 1000A or bigger can be measured by neutron
angle
of
chain, |
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z**h
发帖数: 224 | 15 if you are running neutron or x-ray reflectivity, your sample has three
different layers at first. after you annealed it, these layers mergered
together. will the critical angle change or not? Thanks. |
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z**h
发帖数: 224 | 16 it seems you never run such experiments. x-ray can penerate up to 5000A,
neutron can penerate up to 2000A. |
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c***r
发帖数: 4631 | 17 proved by neutron experiments long time ago again. |
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b*o
发帖数: 47 | 18 Just had a long vacation. I remeber that I read it somewhere saying
entanglement length, as estimated from viscoelasticity measurment and
theoretical models, is usually several times longer than the correlation
length of polymer solutions of the same concentration as measured by
light/neutron scattering (?) experiment. Forget the original literature and
the details, just this conclusion vaguely in my memory. These two concepts
seem easy to understand with de Gennes' drawing in his book.
As for t |
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w********h
发帖数: 12367 | 19 now I tend to look at Packing Length to solve the problem.
although Richter has the best neutron machine,
I doubt they develops theory or models themselves.
really a pity.
initially I wanted to attend his meeting with students now,
seems no need leh after his talk... |
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z**h
发帖数: 224 | 20 yes, about neutron spin echo. |
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r****r
发帖数: 14 | 21 linear absorption coefficient (MU) 到哪里查或算，我在NIST的站点上找不到。谢谢
了。 |
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C***S
发帖数: 175 | 22 More specifically, can X-ray or Neutron scattering tell the difference of
polymer in water from water in polymer system. In my case, it is Nafion
ionomer.
Some groups think even in dry state, Nafion still has the polymer in water
structure. I think it is weird. As the Babinet priciple states: due to the
autocorrelation property of scattering, we cannot tell the positive or negtive
image. So A in B case will give the same scattering as B in A.
Am I right? |
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a****n
发帖数: 3082 | 23 Russell, T. P. (1990).
X-ray and neutron reflectivity for the investigation of polymers. |
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n*******e
发帖数: 2213 | 24 no.
small angle neutron scattering. |
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o********e
发帖数: 34 | 25 【 以下文字转载自 ChemEng 讨论区 】
发信人: olivertree (Life is good), 信区: ChemEng
标 题: Postdoctoral Positions in UNIVERSITY OF DELAWARE
发信站: BBS 未名空间站 (Tue Jun 8 21:36:42 2010, 美东)
Link: http://www.che.udel.edu/postdoc.html
POSTDOCTORAL RESEARCHER position is available immediately with Dr. Yun Liu
and Professor Norman J. Wagner in the Center for Molecular and Engineering
Thermodynamics and the Center for Neutron Science of the Department of
Chemical Engineering at the University of Delaware. Initial appoint |
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w********h
发帖数: 12367 | 26 来自主题: Macromolecules版 - Job 2 Senior Analytical Chemist at Dow
Description
The Dow Chemical Company has an exciting and challenging opportunity for an
experienced PhD level scientist to fill the role of Senior Analytical
Chemist with Dow's Analytical Sciences group located in Spring House,
Pennsylvania. Rapid product/process research, development and manufacturing
require physical and chemical measurements that remove hesitation and
guesswork. Immediate problem solving is critical, including physical
characterization and ide... 阅读全帖 |
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k*********g
发帖数: 791 | 30 最puzzling藕的还是空间和物质的可分性；
物质不断地分下去，是什么？
这个古老的问题，已经puzzling藕N年了。。。
这个不需要物理学知识，完全是个纯逻辑问题、纯哲学问题，或者说纯数学问提；
空间的可分性，也很paradoxical；
其它的比较简单了；
藕斗胆评论几个：
1 ether exists；
以太无处不在；建议研究以太动力学，ether dynamics；
以太很难被直接观测，但是，在weak interaction的时候，是以太造成了W＋，W－，Z
2 电荷到底是什么？
什么东西都被看成是运动了、能量了，连质量都没有被放过；只有电荷是个例外；
what the hell is the charge？
藕speculate，电荷也是一种运动形式，跟spin自旋 很项似；
3 CQCD， computational quantum chromodynamics
量子色动力学，一个对付proton、neutron里面的quark的theory，是个呈现强烈非线性
的东西；故，没有exact solution，asymptotic之流也拿捏不定它；实验，对付p |
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S*****n
发帖数: 6055 | 31 对的。。。我的意思是没有synchrotron source的地方肯定没有neutron source。。。
脑子不清楚了。。。 |
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c**2
发帖数: 35 | 32 两个是相互独立的，没看懂为什么没有synchrotron就没有neutron... |
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M*********m
发帖数: 2024 | 34 我们各自介绍一下自己的研究方向，如果以后有什么专门而又悬而未决的问题，我可以
把文章转入你的信箱，也可以增强互信，在这个网络空间得到一定的透明度。随着大家
逐渐在各个领域展露头角，如果需要协作，这也算是一个基础吧。
可以简单说说啊，比方什么凝聚态，高能，低温，材料，等等。呵呵，都发包子！
实验凝聚态：
pqinsheng: 实验凝聚态, LT-STM.
ansh: 实验凝聚态
Starcraft114: 实验凝聚态，STM, 磁性材料
Xyatoo: 实验凝聚态，硅量子点的光学特性
Chenxi17: 凝聚态，磁性物理
Ac: 氧化物磁性半导体的磁学和自旋相关输运
phasespace: 实验凝聚态物理
Zhane: 固体物理电特性？
Microsystem：高能物理转到凝聚态物理，半导体器件方向
Wokaowokao: 氮化物的合成
yaokent: 计算凝聚态物理
医学物理：
UMMS: 2005年转到Medical Physics，以前拿的是天体物理的Ph.D.，主要的方向是引力
波（Gravitational Wave），曾是LIGO的postdoc，最初做高能伽玛（TeV g... 阅读全帖 |
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g***e
发帖数: 4074 | 36 说白了就是一个neutron scattering的测量。加上这个analogous string 的 idea
和漂亮的彩图，made it a science。
离magnetic monopole其实很遥远。 |
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b*********n
发帖数: 2284 | 37 脉冲星,致密天体理论其实就是统计物理,固体物理+粒子
前几年,这个领域比较牛的一个人shri kulkani有一片nature文章,其中有一句话,大意是
the best place to test condensed matter theories is a neutron star... |
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s*****n
发帖数: 1279 | 38 我不是搞NMR的，不过最近在看一篇文章（也不是NMR方面的），不过其中有一句话介绍
NMR：
Nuclear magnetic resonance analysis techniques are based on the principle
that all isotopes with an odd-
numbered atomic number (Z) have an intrinsic spin when subjected to a
magnetic field and therefore align
themselves along the magnetic field lines.
这句话有没有毛病？为什么要odd number proton？odd number neutron 不行吗？ |
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c****e
发帖数: 2097 | 39 both a pretty elementary, due to pauli exclusion principle you may say.
1) splitting of degenerate states by spin coupling/pairing
2)coulomb repulsion (of protons) compared with fermi levels of neutrons (is that the right name?) |
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c********6
发帖数: 658 | 40 a) n(C, 3r)n-----> n+C-12-----> 3He + n
b) C(n, 3r)n-----> C-12 + n----> 3He + n
n is neutron, C is carbon,
我计算得到a 和 b的 Q value energy 一样，Q《0
那 a, b的thershold energy 会一样吗? 我计算得到a, b的thershold energy相差悬殊
，为什么？ |
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o********e
发帖数: 34 | 41 【 以下文字转载自 ChemEng 讨论区 】
发信人: olivertree (Life is good), 信区: ChemEng
标 题: Postdoctoral Positions in UNIVERSITY OF DELAWARE
发信站: BBS 未名空间站 (Tue Jun 8 21:36:42 2010, 美东)
Link: http://www.che.udel.edu/postdoc.html
POSTDOCTORAL RESEARCHER position is available immediately with Dr. Yun Liu
and Professor Norman J. Wagner in the Center for Molecular and Engineering
Thermodynamics and the Center for Neutron Science of the Department of
Chemical Engineering at the University of Delaware. Initial appoint |
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c**m
发帖数: 1632 | 42 CPT symmetry sets the limit for the neutron/antineutron mass difference. If
we saw some anomaly in the nuclear magnetic moment induced hyperfine
structure from the anti-atom, that will be interesting, although I strongly
doubt CPT violation could happen in such energy scale. But you know, it's
always worth of probing. |
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J**a
发帖数: 215 | 43 这是典型的吃不到葡萄说葡萄酸吧。
不仅在中国，在世界各地作为通讯作者发表文章在science, nature, cell上，都能极
大的改变一个PI的学术境地。而无数的新发现最早发表在这些刊物上，最早粒子的波性
的发现，neutron的发现，DNA的结构，第一个人类基因组计划，第一个克隆技术，第一
个原子分辨率的蛋白结构的解析，最早的细胞凋亡(cell programmed death)的发现。
。。等等。 |
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J**a
发帖数: 215 | 44 这是典型的吃不到葡萄说葡萄酸吧。
不仅在中国，在世界各地作为通讯作者发表文章在science, nature, cell上，都能极
大的改变一个PI的学术境地。而无数的新发现最早发表在这些刊物上，最早粒子的波性
的发现，neutron的发现，DNA的结构，第一个人类基因组计划，第一个克隆技术，第一
个原子分辨率的蛋白结构的解析，最早的细胞凋亡(cell programmed death)的发现。
。。等等。 |
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o****e
发帖数: 916 | 45 why the mass of a neutron is not a universally constant value
到处都找不到答案。求高手指点 |
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s*******i
发帖数: 12823 | 46 neutron的静止质量当然是常数了，谁告诉你不是常数的？
939.6MeV |
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n*****b
发帖数: 2235 | 47 http://cornellcas.tumblr.com/post/53215439683/physics-nobel-lau
Physics Nobel Laureate Kenneth Wilson Dies
Physics visionary Kenneth G. Wilson, winner of the 1982 Nobel Prize in
Physics, died at the age of 77 on June 15 in Maine of complications
following a lymphoma.
“Ken Wilson was one of a very small number of physicists who changed the
way we all think, not just about specific phenomena, but about a vast range
of different phenomena,” said Steven Weinberg, a fellow physics Nobel
Laureate.
The... 阅读全帖 |
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t******n
发帖数: 6242 | 48 CDMS去SNOLAB的话，也还是算美国的项目啊
在加拿大也没有多少collaborator
就像XENON一样，虽然是在实验是在意大利，也还是美国投资的项目
搬过去只是从同时降低宇宙射线和环境本底的低neutron background的技术角度考虑
还有一个考虑的角度是XENON和LUX都是用液氙技术
而CDMS用的是固体硅锗技术
DOE不能把宝压在一个技术上吧
Tevatron和LHC还都搞分别搞两个探测器，建立两个实验合作组呢。
PANDAX现在进展得怎么样了？
听说锦屏山那里太偏，还有塌方影响实验进展？ |
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z**********g
发帖数: 16 | 49 Thesis about the relationship between electron charge
value and electron moving velocity
Yilong Zhuang*
Shanghai Institute of Science and Technology Administration
Jiading,Shanghai 201800
Abstract: “The value of charge has no changes”has not been proved,
but is admitted as a truth.Now that the electron mass can been changed with
it’s moving velocity,then electric charges,as the expression of the
substance’s nature,can be changed accordingly.Following this clue,th... 阅读全帖 |
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z**********e
发帖数: 22064 | 50 【书讯: 在方励之先生去世两周年之际，《方勵之紀念文集》（科學卷），由明鏡出版
社出版了。全书收集了74篇不同作者的回忆文章。作者中有方先生的尊师，亲朋好友，
工作中的同事，科研中的合作者，以及方先生不同时期的学生。全书共556页，并收集
了许多作者和方先生的合影，方先生的手迹等照片。书中也列出了方先生所发表科研论
文的目录。《方勵之紀念文集》是缅怀方先生，研究方先生的一部重要的书籍。】
方励之老师曾跟我说，他是科大建校（1958年）时最早的一批教师之一。我是1962年考
入中国科技大学的，但是，我同方励之老师的相识却不在我读书期间，地点也不在北京
玉泉路的校园里。那时我是近代力学系的学生，普通物理课是由物理教研室的老师来上
，但是他没有被安排给我们授课，无缘相识。
最初注意到方励之的名字，好像是在1973年。那一年，我离开学校已有五年，在昆明钢
铁厂已经当了三年烧锅炉的工人。当时厂里买了一台日本进口的扫描电子显微镜，为了
翻译它的英文说明书，把我从车间调到厂技术处的资料室，这使我有机会接触到一些中
外文的科技资料。此时，1971年9月发生的林彪外逃事件已经过去两年，文化大革命已
成强... 阅读全帖 |
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