d*****s
发帖数: 313 | 1 I know if the self-assembly happens on surface, you can use X-ray to
characterize its structure. Not normal XRD though. basically X-ray
reflectivity and grazing incidence diffraction in synchrotron sources. |
|
s*****y
发帖数: 27 | 2 who is doing liquid crystal research, I am interesting in this, especially by
x-ray
diffraction. |
|
s*****y
发帖数: 27 | 3 in my lab, only me doing x-ray, so I can just ask my boss, but he is veyr
busy, so I am so hard to learn it by myself, I am doing x-ray diffraction for
banana-shaped LC , look like I am a sitting duck now. I really hope someone
can talk to me about x-ray, so I can get a little sense. anyway, thanks lots.
especially by |
|
a***u
发帖数: 9 | 4 If your Si wafer has a thick oxide layer on the top, the broad peak might be
due to the oxide. You can measure the oxide thickness with ellipsometry.
Si wafer is single crystalline. When you rotate the wafer, you will probe
translational symmetry along different directions. For polycrystalline sample
with isotropic orientation, you will see the same diffraction pattern when
rotating the sample. I think it will be more helpful to ask these questions to
people from materials science major. |
|
b**s
发帖数: 589 | 5 The new polymer was developed by Naveed Zaidi and his colleagues in
Durham's organic electroactive materials group. The team created the new
polymer from two compounds, emeraldine base polyaniline (PANi) and
tetracyanoquinodimethane (TCNQ). They chose PANi because it is a metal-like
electrical conductor that is stable in air. TCNQ was chosen because of its
propensity to form charged particles called free radicals........ X-ray
diffraction data showed an increase in the alignment of the poly |
|
d********a
发帖数: 3698 | 6 江湖救急 ，帮忙拉
谁有比较好的书或网站介绍晶体学.Crystallography，点群，空间群，结构符号的
这学期选了门DIFFRACTION OF Materials 的课，
老师一口老印英语基本听不懂啊，而且飞快，一天一章。
下周就要交作业
多谢先 |
|
|
c********x
发帖数: 232 | 8 whoever claims they can tell a in b or b in a through diffraction is
bullshiting. Scattering only tells intensity distribution. That means
all the contrast (A-B) and (B-A) will get squared. Therefore you can
never tell whether it is A-B or B-A. |
|
w***t
发帖数: 86 | 9 需要做单晶XRD (single x-ray diffraction)学校里没这个条件，我想找外面的公司做
，有人知道能提供这种服务的公司吗？谢谢 |
|
|
c********x
发帖数: 232 | 11 pretty much national user facility only. the turnover time with proposal
is pretty long.
if you just want the self assembled structure, transmission can do it
too. of course you have to assume that you really have a 2d, instead
of 3d morphology, which is not a given. |
|
S*****n
发帖数: 6055 | 12 还行吧
BNL如果现在交proposal，中了的话5月就可以做 |
|
w********h
发帖数: 12367 | 13 觉得费事，批了也要等，不批不是无聊么，还泄漏了idea。。。不如掏钱爽快。。。 |
|
m***r
发帖数: 225 | 14 Find a collaborator, then you all set!
That is what I do nowadays if I need to use LBNL or ANL or BNL. |
|
w********h
发帖数: 12367 | 15 介个。。。不能跟你们搞合成的比阿，跟搞物理的人合作合作，有点意义。。。
那些，对我来说，只是工具而已。。。 |
|
F****N
发帖数: 110 | 16 材料 是 x-ray diffraction and high resolution TEM for semiconductor
materials and nano-materials
FEA是算法研究和modeling of technological process like metal forming
and 材料失效及应力分析 |
|
w******t
发帖数: 107 | 17 （一）多孔材料简介
多孔材料，顾名思义，就是有很多孔的材料；不仅要外面有孔，里面也要有孔，这样才
名副其实。一般呢，这孔的物理结构有三种：
（1）里面的孔全部被封住了，孔与孔之间是实心儿的固体隔开，无法通过普通的物理
方法测得其内部构造和pore volume（比如说，常用的氮气表面吸附法）。但是可以用
有穿透力的工具搞定，比如说，投射电镜（TEM）和X射线衍射/散射(Small-angle X-
ray scattering or X-ray diffraction）。
（2）里面的孔被“半封住”。也就是说，相邻的孔之间的固体墙壁内部，藏有狭小的
通道。分子可以经过这些小管子在孔之间窜来窜去，但是比较费劲：没办法，路太窄，
分子们太肥。小一点的分子呢，勉强可以来回跑；稍微大一点儿的呢，进去了就出不来
了，卡在里面了；再大一些的呢，干脆就进不去了，只是在多孔材料颗粒外面绕一圈儿
。当然，相对于不同尺度的分子，这个限制是不一样的。
（3）孔与孔之间是很宽敞的通道，于是分子可以在整个多孔材料颗粒内部自由流通；
同时颗粒内外，对于一定尺寸的分子而言，都是accessile的。不过，如果一个分 |
|
l******u
发帖数: 2314 | 18 黑线肯定是样品量不够，都是noise，峰都没出来。
505的那个峰肯定不是RBM，不知道那位能解释下？大概就这个不合理吧。
红线的谱图很棒啊，至于算直径，定量不得吧？公式里的经验常数肯定不是100%准确的
。和TEM/diffraction误差超过10%，很正常啊。 |
|
T****i
发帖数: 2190 | 19 请参阅williams and carter 写的 Transmission Electron Microscopy的第二本
Diffraction |
|
m****s
发帖数: 4 | 20 Interpretation of electron diffraction patterns [by] K.W. Andrews, D.J.
Dyson [and] S.R. Keown 2Nd ed.
Andrews, Kenneth William
书里有标准的衍射图，一比就知道了 |
|
R****i
发帖数: 2387 | 21 Rep. Prog. Phys. 62(1999)1471-1524
Electron diffraction and microscopy of nanotubes.
S Amelinckx et,al
碳管电子衍射集大成之文献，最近正在研究中。 |
|
h**e
发帖数: 1 | 22 Diffraction pattern record only the scattering amplitude (or intensity), not
the phase. There is no direct way to reconstruct an image from the edp. |
|
S*****n
发帖数: 6055 | 23 还有，如果一定想用scattering/diffraction的结果来算particle size，其实最好用
中子散射，light scattering波长太大，X-ray波长太小。。。
说了这么多，BM给发包子不？
CO
particle |
|
S*****n
发帖数: 6055 | 24 老板：我们要把particle做小，做到XRD上看不到diffraction pattern。。。
Synthon：。。。。。。 |
|
x*******2
发帖数: 5333 | 25 or i could upload mine. anyone could help me take a look? |
|
|
|
T****i
发帖数: 2190 | 28 XRD的话去ICDD找标准谱，电子衍射的话自己拿圆规按比例画几个圈就好了
或者用JEMS模拟for both |
|
x*******2
发帖数: 5333 | 29 do you have JEMS? I just need 电子衍射 to compare with mine. thank you |
|
T****i
发帖数: 2190 | 30 有，但是要build models，很麻烦
你要知道是什么晶体结构，用r*d=constant你自己就可以算出多晶环的半径比例，用不
着模拟 |
|
x*******2
发帖数: 5333 | 31 i see. but the error is about 8%. is that acceptable? |
|
S*****n
发帖数: 6055 | 32 话说俺以前做TEM都是找人帮忙，这一日终于痛下决心自己去找TEM manager，说我要个
training，于是有了以下对话：
Me：除了正常的imaging之外，你这里有EDX和EELS么？
Manager：没有
Me：那我还想做Electron Diffraction，这台仪器上有么？
Manager：有，但是自从买来就没人用过。。。
Me：那Dark Field Imaging可以做么？
Manager：这个。。。呃。。。你先回去吧。。。 |
|
T*M
发帖数: 48 | 33 从前到后有gun，condenser aper (1,3), obj lens, int lens ... 如果有GIF还有调.
..
这里illumination system跟样品没关系，图像的FFT跟电子衍射也不是一回事，除了
int lens 的stig和diffraction focus需要直接用电子衍射来调（呵呵，估计这里没有
人调过这俩），我一时想不起来还有啥需要电子衍射来做alignment？ |
|
w***t
发帖数: 86 | 34 需要做单晶XRD (single x-ray diffraction)学校里没这个条件，我想找外面的公司做
，有人知道能提供这种服务的公司吗？谢谢！ |
|
s**l
发帖数: 869 | 35 谢谢
看到的UV光源大都从200nm起
请推荐合适的仪器 |
|
|
s**l
发帖数: 869 | 37 x-ray光源波长能到100nm左右吗？
我看到的大都是几个埃的 |
|
s*********a
发帖数: 113 | 38 it seems the only d-spacing which is about twice as d101 is d100, which is 4
.593 vs. 2.488. But 100 seems a forbidden spot in diffraction pattern. |
|
T*M
发帖数: 48 | 39 如果用得很多而老板又有钱的话，可以劝他/她买imaging plates
imaging plates 不仅x-ray用很多，电子衍射也用的。
好处：
1. digital analysis for quantitative electron diffraction
2. high dynamic range and resolution
Fuji的已经很好，Ditabis的dynamic range和分辨率就更高
3. 重复使用 |
|
B*****n
发帖数: 654 | 40 谢谢,
很详细,我先去"闭观",过段时间,分析出来后,再来请教
diffraction |
|
m***c
发帖数: 1403 | 41 TEM的diffraction什么样？ 这决定你的是真正amorphous还是只是晶粒小。 |
|
w**y
发帖数: 189 | 42 老板给的课题，关于polymer nancomposite。一直解决不了的问题是如何让nanoclay
well dispersed in polymer。
我想请教的问题是：
1.怎么让Na-MMT clay在水中分布均匀，听说可以用超声波分散法，不知道哪些可行？
2.一般用X-ray diffraction 去看分布情况，也有用TEM的，具体怎么测这种液体样品？
3.这个课题我感觉很难，而且不是很工业化，做不下去怎么毕业啊？
我，谢谢大家啦~ |
|
l*******0
发帖数: 215 | 43 【 以下文字转载自 Postdoc 讨论区 】
发信人: limin1980 (limin1980), 信区: Postdoc
标 题: Chemist Postdoc position
发信站: BBS 未名空间站 (Mon Nov 28 20:16:59 2011, 美东)
The Advanced Energy Department at Lawrence Berkeley National Laboratory has
an opportunity for a Chemist Postdoctoral Fellow to prepare, characterize
and optimize electrode materials for rechargeable lithium-ion batteries.
This position supports the research activities in the Electrochemistry Group
in developing the next-generation batteries for use in elec... 阅读全帖 |
|
k******6
发帖数: 7 | 44 Purpose
The Center for Nanophase Materials Sciences (CNMS) at Oak Ridge National
Laboratory (ORNL) is seeking a Postdoctoral Research Associate with
experience and expertise in organic spintronics, with a strong emphasis on
the design, fabrication and characterization of organic spintronic device.
The CNMS http://cnms.ornl.qov/ is a nanoscience research facility supported by the Office of Science, U.S. Department of Energy (DOE). The CNMS has a diverse spectrum of nanoscience activities includ... 阅读全帖 |
|
c******k
发帖数: 1140 | 45 Philips PANalytical X'Pert PRO x-ray diffraction system
Sample area:2cmx2cm
做校准时的配置：
Incident beam optics: Beam Attenuators & Filters Cu/Ni, divergence slits 1/
32
但是做Z scan时，找不到信号，
我做大点的wafer时就没问题，是不是光束太宽，要用个mask啥的？请高人执教。 |
|
a*******r
发帖数: 7558 | 46
光被月亮这个大球体散射，为补充几何光学方法来研究背散射等特殊方向，
引入Complex Angular Momentum（CAM)方法 ，就可得到Regge Pole等
高能里的东西。至于散射截面（振幅）的展开，和量子里面的WKB等的联系
更是千丝万缕了。
Nussenzveig的是本
好书，用简单的数学把球体散射这个问题的经典力学，光学，量子，等方面都
串了起来。建议你去读读。 |
|
m*******r
发帖数: 481 | 47 Can any friend recommend good books on X-ray diffractions of thin films?
hope this is the right board to ask this question. Thanks a lot! |
|
w***t
发帖数: 86 | 48 需要做单晶XRD (single x-ray diffraction)学校里没这个条件，我想找外面的公司做
，有人知道能提供这种服务的公司吗？谢谢！ |
|
|
z**********i
发帖数: 8 | 50 （1）Title: Diffraction theory applied to X-ray imaging with clessidra prism
array lenses
Author(s): De Caro, L; Jark, W
Source: JOURNAL OF SYNCHROTRON RADIATION Volume: 15 Pages: 176-184
Published: 2008
（2）Title ：On the use of clessidra prism arrays in long-focal-length X-ray
focusing
Journal of Synchrotron Radiation
Volume 15, Issue 4, Date: July 2008, Pages: 411-413
两篇都在杂志Journal of Synchrotron Radiation上，John Wiley数据库有收录。
谢谢帮助下载，谢谢！我的邮箱为：x************[email protected] |
|
