z****6
发帖数: 10776 | 1 不是算法的问题啊
Limitations of Digital ICE
Digital ICE is used to detect scratches and dust during transparent film
scan and not applicable for opaque document scanning. Where Chromogenic
black and white films are supported by Digital ICE, other black and white
films containing metallic silver (which form from silver halides during the
development process of the film) are not. This is because the long wave
infrared light passes through the slide but not through dust particles. The
silver particles refl... 阅读全帖 |
|
n**b
发帖数: 13203 | 2 【 以下文字转载自 SanFrancisco 讨论区 】
发信人: qdssl (honeydot), 信区: SanFrancisco
标 题: FDA查处美国海尔斯制药有限公司在中国热卖的一氧化氮等保健产品 (转载)
发信站: BBS 未名空间站 (Sat May 5 13:29:53 2012, 美东)
发信人: qdssl (honeydot), 信区: LosAngeles
标 题: FDA查处美国海尔斯制药有限公司在中国热卖的一氧化氮等保健产品
发信站: BBS 未名空间站 (Sat May 5 13:27:59 2012, 美东)
Health One Pharmaceuticals, Inc. of El Monte, CA was warned by the FDA that
a September/October inspection of the company's dietary supplement
manufacturing facility revealed serious violations of FDA's Current Good
Manu... 阅读全帖 |
|
p****m
发帖数: 510 | 3 科学竞赛得奖的90%是中国血统。 o yeah!
http://news.yahoo.com/calif-teen-takes-100k-national-science-pr
“Calif. teen takes $100K national science prize”
WASHINGTON (AP) — A high school student from California won a $100,000
scholarship Monday for research that created a tiny particle she likened to
a "Swiss army knife of cancer treatments" because of its precision in
targeting cancer tumors.
Angela Zhang, 17, of Cupertino, Calif., won top individual honors at the
Siemens Foundation's annual high school science... 阅读全帖 |
|
f**********r
发帖数: 18251 | 4 【 以下文字转载自 Military 讨论区 】
发信人: smartkevin (PE), 信区: Military
标 题: Re: 普鲁士蓝解毒机理
发信站: BBS 未名空间站 (Wed May 1 11:49:11 2013, 美东)
为什么一帮人就喜欢动嘴皮子不喜欢动手狗一下？明明说了是Fe4[Fe(CN)6]3，哪来的
钾？
https://en.wikipedia.org/wiki/Prussian_blue
Prussian blue
From Wikipedia, the free encyclopedia
This article is about the pigment. For the musical duo, see Prussian Blue.
See also: Midnight blue
Prussian blue
IUPAC name[hide]
Iron(II,III) hexacyanoferrate(II,III)
Other names[hide]
Berlin blue
Ferric ferrocyanide
Ferric hexacy... 阅读全帖 |
|
r******k
发帖数: 97 | 5 Gold growing on trees? Scientists find small deposits in gumleaves
Australian geochemists publish paper showing how trees act 'as a hydraulic
pump … drawing up water containing the gold'
Scientists from Australia’s national science agency, the Commonwealth
Scientific and Industrial Research Organisation (CSIRO), have proved that
the leaves of certain eucalyptus trees contain minute amounts of the
precious metal that have been naturally absorbed.
Eucalypts in the Kalgoorlie region of Western Aust... 阅读全帖 |
|
M*****e
发帖数: 11621 | 6 新物理来了！刚刚出炉没几天，还热乎着呢。
https://www.simonsfoundation.org/quanta/20130917-a-jewel-at-the-heart-of-
quantum-physics/
@河马
Physicists have discovered a jewel-like geometric object that dramatically
simplifies calculations of particle interactions and challenges the notion
that space and time are fundamental components of reality.
The revelation that particle interactions, the most basic events in nature,
may be consequences of geometry significantly advances a decades-long effort
to reformulate quantum... 阅读全帖 |
|
z***i
发帖数: 8285 | 7 俺也搭车发篇数学论文：
论 may be = may not be 不再成立
新物理来了！刚刚出炉没几天，还热乎着呢。
https://www.simonsfoundation.org/quanta/20130917-a-jewel-at-the-heart-of-
quantum-physics/
@河马
Physicists have discovered a jewel-like geometric object that dramatically
simplifies calculations of particle interactions and challenges the notion
that space and time are fundamental components of reality.
The revelation that particle interactions, the most basic events in nature,
may be consequences of geometry significantly advances a de... 阅读全帖 |
|
o******1
发帖数: 12177 | 8 He is correct.
Negative temperatures can only exist in a system where there are a limited
number of energy states (see below). As the temperature is increased on such
a system, particles move into higher and higher energy states, and as the
temperature increases, the number of particles in the lower energy states
and in the higher energy states approaches equality. (This is a consequence
of the definition of temperature in statistical mechanics for systems with
limited states.) By injecting ener... 阅读全帖 |
|
v***r
发帖数: 1046 | 9 不胜惶恐。颂读几个关键词，希望在您老心目中加点分:
"文科生，截面, correlation, two-particle system"
"文科生，截面, correlation, two-particle system"
"文科生，截面, correlation, two-particle system" |
|
s********b
发帖数: 3 | 10
回应：
一、注意“长老”不是“老年人”可能是年轻人或中年人。请长老抹油祷告是很正常的
，任何相信圣经的教会都会有人相信并实践的。
二、我不清楚怎样解释‘“圣经”“新约”明确要求女人在教会要“闭口不言”’。
我不知道这个教导是不是绝对的，或“明确”。
例如，哥林多前书十一章，
4 凡男人祷告或是讲道（讲道或作说预言下同），若蒙着头，就羞辱自己的头。 5 凡
女人祷告或是讲道，若不蒙着头，就羞辱自己的头。因为这就如同剃了头发一样。 6
女人若不蒙着头，就该剪了头发。女人若以剪发剃发为羞愧，就该蒙着头。
这些经文意为，女人可以讲道（先知预言）只有蒙头（要不就剪头发）就可以了。与哥
林多前书十四章34-35节的教导有异。我没时间具体查原文希腊文怎么写的。
在网上找到一篇有关文章。（比较长）
http://www.ntrf.org/articles/article_detail.php?PRKey=16
Correctly Interpreting 1 Corinthians 14:33b-35 (Part 1＆Part 2)
by Steve Atkerson
If you ever wis... 阅读全帖 |
|
n********n
发帖数: 8336 | 11 game of chance
probability vs certainty
entanglment: spooky action at a distance
Impossible to comprehend
teleportation
information transfer: quantum state of the particles
destroy the original "me'
Information is me, not the physical particles
Quantum computer: for prediction of certainty! likr weather forecast
omnipresence of quantum particles
how uncertainty of quantum world leads to certainty of macroscopic world:
missing gap
all possibilities disappear, resulting in a single certain outcome |
|
r*******c
发帖数: 1060 | 12 是哦，我很想知道死亡到投胎重生的那个过程，所以，我今年把那个THE TIBETAN BOOK
OF LIVING AND DYING 看了一遍，
里面提到对轮回的看法，和我之前听说的有不一样哦：
The basis on which Buddhists accept the concept of rebirth is principally
the continuity of consciousness. Take the material world as an
example: all the elements in our present universe, even down to a
microscopic level, can be traced back, we believe, to an origin, an initial
point where all the elements of the material world are condensed
into what are technically known as "space particles." Thes... 阅读全帖 |
|
r*******c
发帖数: 1060 | 13 是哦，我很想知道死亡到投胎重生的那个过程，所以，我今年把那个THE TIBETAN BOOK
OF LIVING AND DYING 看了一遍，
里面提到对轮回的看法，和我之前听说的有不一样哦：
The basis on which Buddhists accept the concept of rebirth is principally
the continuity of consciousness. Take the material world as an
example: all the elements in our present universe, even down to a
microscopic level, can be traced back, we believe, to an origin, an initial
point where all the elements of the material world are condensed
into what are technically known as "space particles." Thes... 阅读全帖 |
|
Y**u
发帖数: 5466 | 14 ☆─────────────────────────────────────☆
wuyu (wuyu) 于 (Fri Jun 15 14:49:43 2012, 美东) 提到:
还在修改中，未把参考文献加上。请大家批评
按照佛法讲，“心”“识”的定义是“能缘”，具有指向，观察“所缘”的作用。他依
附于“心所依处”位置在心脏的血液里。由“安般息念”和“慈心念”来练止禅，其目
的是培养定力，即觉察的纯净和持久的质量。包括“行禅”在内的“观禅”，其目的是
培养念力，即对当下身心现象觉察的的敏捷，精细，和全面。在十二缘起中，佛陀教诲
“识缘名色”。现代量子物理学认为：物质都有波粒二重性，因被观察，波性塌方而呈
现粒性。这与佛学的解释很相近：能观察的“识”缘生物质（色）和意识（名）现象。
这个“能觉察”的“心”的是否有生物学基础呢？这是哲学和现代神经科学面对的一个
最基础也是最棘手的问题。
神经生物学认为意识现象基本上是大脑的功能。意识活动相当于佛法的“名”法，即五
蕴中的“ 受，想，行，识”。 其中，“想”蕴的定位最简单，由负责记忆中枢大脑海
马体实行。“受” 蕴则包括感觉外周刺激（... 阅读全帖 |
|
n********n
发帖数: 8336 | 15 game of chance
probability vs certainty
entanglment: spooky action at a distance
Impossible to comprehend
teleportation
information transfer: quantum state of the particles
destroy the original "me'
Information is me, not the physical particles
Quantum computer: for prediction of certainty! likr weather forecast
omnipresence of quantum particles
how uncertainty of quantum world leads to certainty of macroscopic world:
missing gap
all possibilities disappear, resulting in a single certain outcome |
|
s******e
发帖数: 16668 | 16 能不能大致解释一下这个standard model?
我不能明白这句话，it was important because it gives matter mass。
如果Higgs Boson不存在，物质就没有质量吗？是不是这个意思？
我对质量的理解还是在一个宏观粗浅的层面上，于是不能理解为什么Higgs Boson的存
在会给物质质量。
还有这段话：
They aren’t absolutely sure this particle is the Higgs but it has some key
Higgs-like properties. In the coming months, the scientists plan to study
how easily the new particle is made and the various ways it transforms
itself into other particles. If it does anything that contradicts the
predictions of the standard mode... 阅读全帖 |
|
h****r
发帖数: 258 | 17 Anyone has an idea about my problem?
Suppose I divided a cube in 3D into a series of voxels (say 100x100x100). In
some of these voxels, I randomly place some particles. The total number of
particles is about 500,000. On center of each of these voxels, I need to
calculate a value which is the function of the distance to the closest
particle. Is there an efficient way to do this?
Now the only approach I could think of is using a Kd-tree. But I think kd-
tree is more suitable for situations when |
|
发帖数: 1 | 18 Which is the most powerful OS for programmers?
Obviously Linux, Don't believe it:
Just take a look.
1.The Most Powerful Supercomputers Today Run Linux!
The talk about the top 500 fastest supercomputers, 90 per cent of them run
on some variant of Linux.
2. Linux Powers Japan's Bullet Trains
We all know about the Shinkansen, (popularly known as Bullet Train), which
is the network of high-speed railway lines in Japan. The trains are famous
for their super fast speeds of 240–320 km/h. The Shinkansen... 阅读全帖 |
|
s*****t
发帖数: 1994 | 19 No evidence shows that. Sunspots activities will
enhance the brightness of the sunspot area, give
out strong X-ray emissions, and high-energy particles
including electrons and protons. Actually, X-rays
and particles can hardly reach the Earth because of
Earth's atmosphere (actually ionosphere and magnetophere)
will block them out. Particles can interact with
the magnetosphere to form the aurora (or Northern light)
in high latitudes. So, sunspot activity can hardly
change anything on the Earth, e |
|
m**o
发帖数: 13 | 20 P32 has a little bit high emission of beta particles. Beta particles are
completely attenuated by small thicknesses of common materials.Therefore, they
do not pose an external source of radiation dose. Even a high energy beta
particle from a P-32 decay event can only penetrate about 8 millimeters of
tissue. Our radiation-sensitive organs are typically at least 12 to 25
millimeters below the skin surface. However, a beta emitter can cause
radiation dose if ingested. So don't worry too much.
And u |
|
p*******r
发帖数: 59 | 21 Career Opportunities at JCVI Infectious Disease (8 Positions)
The PIs did not ask me to post here, I did this just in case someone is
looking for similar positions but did not see these, and I would be happy to
see some chinese fellows to come. All the PIs are very nice.
All listed at
https://careers.jcvi.org/careers/Careers.aspx
http://www.jcvi.org/
No. 1 & No. 2 Post-Doctoral Fellows
Job Responsibilities
JCVI is looking for two Post-Doctoral Fellows to join the Infectious Disease
Group in our ... 阅读全帖 |
|
B*****e
发帖数: 1005 | 22 140后的几个也不是美国AP啊，文章比跟前几个有距离
140 黄亿华 男 1971年10月 中国科学院生物物理研究所 生命
科学 2004年02月毕业于[美国]康奈尔大学 [美国]休斯医学研究所/西南医学中
心 讲师
1: Huang Y, Smith BS, Chen LX, Baxter RH, Deisenhofer J. Insights into pilus
assembly and secretion from the structure and functional characterization of
usher PapC. Proc Natl Acad Sci U S A. 2009 May 5;106(18):7403-7. Epub 2009
Apr
20. PubMed PMID: 19380723; PubMed Central PMCID: PMC2670885.
2: Lin SC, Huang Y, Lo YC, Lu M, Wu H. Crystal structure of the BIR1 doma... 阅读全帖 |
|
e**r
发帖数: 1144 | 23 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 |
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n********y
发帖数: 187 | 24 那要追根溯源就没有所谓原创了,这20年之前就有用particle tracking小于光学衍射极
限的工作了
本同行觉得STORM的第一篇文章的原创是怎样从一堆PARTICLE中检一个---可惜这最后的
8股没有细说到底MJR的IDEA是哪部分;老板不会连单PARTICLE小于光学衍射极限都不会
用吧?
Steven |
|
t****b
发帖数: 47 | 25 2012年11月13日，新的生物学刊物eLife发表论文：中国科学家攻克了一个长期困扰国
际科学界的难题，而这一基础科学问题也与人类、特别是中国人民的健康相关。
过去，世界和中国忽略了1980年代我国科学家在条件艰苦时代做出重要贡献，我们现在
应该赞广西肿瘤防治研究所的严瑞琪和苏建家等、北京第二传染病院的余昌晏等和中国
医学科学院的庞其方等建立乙肝动物模型；
现在，我国已经有条件和能力改革科学管理体制机制、提供适当环境，让一些科研机构
年富力强的科学家心无旁骛，如北京生命科学研究所的李文辉带领学生和同事发现乙肝
病毒受体；
将来，希望全国科研机构能推广适合各个学科和机构自身规律的体制机制改革，使大批
年轻人集中精力在专业上充分发挥作用，他们大有作为才能使中国的科学大有希望。
肝炎和肝炎病毒
肝炎在全世界有广泛的危害，中国人群肝炎患病率尤其高。多种病毒导致病毒性肝炎：
甲、乙、丙、丁、戊（A、B、C、D、E）等。
全球二十亿人曾感染乙型肝炎病毒（HBV），慢性乙肝感染超过3.5亿人。即使在乙肝疫
苗已经研制成功多年以后，我国还有逾九千万人感染过乙肝病毒，上千万乙肝患者，每
年感染超过百万... 阅读全帖 |
|
l**********1
发帖数: 5204 | 26 名校 新人PhD 的 有关 关键词的 博士论文 最近三年到五年的 至少100篇
其全部PDF 文档或hard paper 都参考一下的话 可以看出点 如何建筑这幢楼的 端倪了
吧 (possible)
比如
citation from UBC 2009 PhD dissertation: "Particle Markov Chain Monte Carlo"
by
Roman Holenstein
full text pdf link:
HTTP: //www.cs.ubc.ca/grads/resources/thesis/May09/Holenstein_Roman.pdf
Monte Carlo methods have become the standard tool to solve many problems in
statistics and scientific computing. Examples are abound, and include
instances in
Bayesian statistics (posterior estimat... 阅读全帖 |
|
n**r
发帖数: 103 | 27 Ocean NanoTech has an immediate opening for a full time Research Scientist
or part time Consultant to support our development of nanoparticle-based
tools and reagents.
Job Description:
The candidate will be a member of our development team.
1. Study surface chemistry of the particles for various applications and
provide suggestions to our Chemists for surface functionalization/
modification;
2. Conjugate nanoparticles and different biomolecules;
3. Develop nanoparticle-based assays.
Qualificati... 阅读全帖 |
|
m***c
发帖数: 637 | 28 招聘：世界500强上海研发中心诚聘以下物理化学生物医药海外留学人士。
If you are interested, please email your CV to d****[email protected] with the
position that you are applying as the title.
Assistant Research Scientist-Food Science
Assistant Research Scientist-Polymer
Assistant Research Scientist-Polymer
Assistant Research Scientist-Rheology in Deposition
Assistant Research Scientist-Water Purification
Assistant Research Scientist –Deposition
Product Development Technologist-Skin GDC护肤类产品开发研究(For Skin
Category)
Research Associate (Me... 阅读全帖 |
|
z*********4
发帖数: 146 | 29 The Archimedes particle-sizing instrument from Affinity Biosensors
took Gold in the Pittcon Editors’ Awards for its approach to particle
characterization.
It uses an ultra-high-resolution mass sensor to weigh each particle,
giving true sub-micron counting measurements of mass and size with
excellent resolution, throughput, reproducibility, and accuracy. The
measurements do not depend on optical properties or shape, and there
is no need for complex ‘‘inversion algorithms’’ or fractionation. It ca |
|
r********n
发帖数: 149 | 30 http://pubs.acs.org/doi/abs/10.1021/ja2005708
Three-dimensional colloidal crystals made of
ferromagnetic particles, such as magnetite (Fe3O4), cannot
be synthesized in principle because of the strong attractive
magnetic interaction. However, we discovered colloidal
crystals composed of polyhedral magnetite nanocrystallites
of uniform size in the range of a few hundred nanometers in
the Tagish Lake meteorite. Those colloidal crystals were
formed 4.6 billion years ago and thus are much older than
... 阅读全帖 |
|
m***c
发帖数: 637 | 31 再转几个中国上海联合利华内部推荐招聘的位置给大家，尽量找联系人内部推荐。
中国上海联合利华内部推荐，招聘。
If you are interested, please email your CV to d****[email protected] with the
position that you are applying as the title.
Assistant Research Scientist-Polymer
Assistant Research Scientist-Rheology in Deposition
Assistant Research Scientist-Water Purification
Assistant Research Scientist –Deposition
Assistant Research Scientist-Polymer
Work in the Discover in R&D function for the research in Polymer Science
area and perform as an active project/team... 阅读全帖 |
|
S*****n
发帖数: 6055 | 32 想到哪儿说道哪儿
1.你的反应转化率为什么都那么低，只有20-30%？
2.你觉得你做的课题有产业化的可能么？如果有，简单说说产业化的方向。
3.你一直都在做实验，对计算模拟感兴趣么？有没有相关经历？
4.催化剂失活的主要原因都有什么？
5.我们通常讲particle size都是假定particle是球形的，如果你碰到的particle不是
球形的怎么办？
6.你对某某教授最近发表的Science文章怎么看？
7.为什么工业上合成氨工艺的转化率都只有15%左右？如何解决低转化率问题？
8.简单说说轻烃催化重整工艺
9.你做过的最自豪的一件事情
10.你如果可以跟任何人交谈，你想见谁？想问他什么问题？
11.如果你去做postdoc，你会考虑哪些lab？
12.如果你去做faculty，你会选择什么研究方向？
13.给你offer你回来么？
14.你选择雇主的标准是什么？
15.你的工资期望是多少？
16.你五岁时候的理想是什么？
17.你的研究背景既有A又有B，都是我们公司需要的方向。但是在公司里面你只能有一
个岗位，你是选A还是选B呢？
18.你在做表征的时候除了按照仪器说明书操作... 阅读全帖 |
|
b*****r
发帖数: 29 | 33 We are currently looking for passionate and highly-motivated Ph.D. students
to carry out analytical and computational studies on micro-/nanofluidics and
soft materials. The focus of our research group encompasses modeling the
following phenomena: electrokinetic flows in confined geometries, deposition
of colloidal particles during evaporation, dynamic self-assembly of
nanoparticles, self-healing polymer nanocomposites, vesicle-particle
interactions, and wetting and slip on superhydrophobic surfa... 阅读全帖 |
|
f**d
发帖数: 768 | 34 【 以下文字转载自 Statistics 讨论区 】
【 原文由 fyld 所发表 】
通过这种方法怎么计算entropy?
感谢！
或如何理解下面导出的Nc and S?
Suppose there n particles randomly distributed in a region of N positions.
Even if n is much smaller than N, there is a nonzero chance
for coincidence, i.e., some positions will get more than one particles.
Since the probability for a particle to fall in any given position is 1/N,
the number of coincidences is easily estimated by:
Nc=n(n-1)/2 *1/N
(why?)
Let us define R to be the coincidence rate which is the |
|
l*******G
发帖数: 1191 | 35 typical N-body problems.
for limited number of bodies/particles, just use groups of F=ma + constrains
for thousands of particles, have you heard of SPH? Smoothed Particle
Hydrodynamics? Maybe that will be helpful.
量
作
力
证
。 |
|
c*s
发帖数: 2145 | 36
hehe,the surface charge is determined by yhr initiator used, but not by the
species of the particles.
Using KPS, for example,you can get negatively charged particles, no matter
PMMA or PS. while using V50, you can get same particles however, with
positive charge |
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c*******n
发帖数: 1648 | 37 similar to the last one by BF.
Monodisperse
5nm
solid or solidlike (No terminal viscosity)particles in polymer melt
The particle should have enough mobile protons
No aggregation of particles
Easy to synthesize or using physical methods
I think organic chemists here might have seen some of these kinds of well
defined systems. if you have, could you please refer the source? Thanks |
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c*s
发帖数: 2145 | 38 on an individual polymer particles? suppose the size of the particle is ~ 200
nm. the patches stand out of surrounding area with different funtional groups
or hydrophobicity.
Furthermore, how to get these patches symetrically distributed on the
particle?
I do know from a workshop that somebody can do this , but the speaker was
reluctant to give more details. |
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s****e
发帖数: 2934 | 39 By colloidal crystal, I meant indeed crystalline structure formed by colloid
particles. A lot of people are studying so-called colloidal gel when the
colloidal particles are introduced attractive interactions, they can form a
network just like a polymer gel. I am not sure whether these colloidal
particles can form an ordered structure under some special technique.
I knew of some work by David Weitz and probably Whitesides who tried to attain
crystalline order in the micellar solution, but can no |
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m******k
发帖数: 447 | 40 Most particles are around 10 microns. While I cannot filter to collect
particles. I guess there are some emulsion particles inside. Do you know any
way to avoid the formation of micelles or anyway to filter the suspension?
Tons of thanks. |
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w********h
发帖数: 12367 | 41 from wiki
Higgs is reported to be displeased that the particle is nicknamed the "God
particle", as Higgs is an atheist.[7]This nickname for the Higgs boson is
usually attributed to Leon Lederman, but it is actually the result of
Lederman's publisher's censoring. Originally Lederman intended to call it "
the Goddamn particle", because of its elusiveness.
Higgs was promoted to a personal chair of Theoretical Physics at Edinburgh
in 1980. He became a fellow of the Royal Society in 1983 and a fellow |
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b******0
发帖数: 45 | 42 你这particle用来稳定乳液，相当于乳化剂了？这样增大particle浓度，相当于增多乳
胶粒数目。从经典的乳液聚合来看，聚合速率应该增大才对。你两种解释似乎都不能解
释这个问题。第二个解释很不合理，乳液中单体浓度是固定的，与尺寸无关。第一个不
好说，除非自由基都是被particle终止，终止速率要比引发速率快，而且乳胶粒尺寸
决定着终止速率。。。 |
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w********h
发帖数: 12367 | 43 Rank Full Journal Title Journal Impact Factor
1 CHEMICAL REVIEWS 45.661
2 NATURE MATERIALS 36.425
3 Nature Nanotechnology 33.265
4 CHEMICAL SOCIETY REVIEWS 30.425
5 PROGRESS IN MATERIALS SCIENCE 25.870
6 ACCOUNTS OF CHEMICAL RESEARCH 24.348
7 Nature Chemistry 23.297
8 Nano Today 18.432
9 Annual Review of Materials Research 15.629
10 Energy & Environmental Science 15.490
11 ADVANCED MATERIALS 15.409
12 Advanced Energy Mate... 阅读全帖 |
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s****t
发帖数: 2454 | 44 非常感谢！
我就是做的层流的partice tracking， 研究particle在多孔介质中的吸附， 还是one
way coupling的，特别简单，也就是particle 和多孔介质表面的作用力有一丁点复杂
。都觉得这个项目不像是机械系的Ph.D该做的，读了几年还是觉得很心虚，觉得学到的
东西太少，很难找到工作的，我能想到的工业应用也就是滤水器，实在想不到别的了，
不知道有没有，呵呵
我实验室有人做turbulence particle tracking，模型是云层中的液滴运动，也是用的
Fortran，他们的模型也不是完全two way coupling，有一些假设，具体我也没太弄懂
，不过对并行计算要求特别高，天天研究如何提高运算效率，主要是想扩大计算模型的
size。
的了 |
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d*********g
发帖数: 49 | 45 Enhanced ethanol production inside carbon-nanotube reactors containing
catalytic particles
Xiulian Pan, Zhongli Fan, Wei Chen, Yunjie Ding, Hongyuan Luo & Xinhe Bao
Published online: 21 May 2007; | doi:10.1038/nmat1916
First paragraph - Enhanced ethanol production inside carbon-nanotube
reactors containing catalytic particles | Full Text - Enhanced ethanol
production inside carbon-nanotube reactors containing catalytic particles |
PDF (536 KB) - Enhanced ethanol production inside carbon-nanotube |
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m***c
发帖数: 1403 | 46 ......特别精确的particle size非常重要吗？ 1nm似乎都不能叫particle乐，也就是
个cluster,几十个原子。。。 我说的中间大小大概几十到一百个纳米，表面能已经
不是很大了。 这么小的东西，我能想到的只有HRTEM了，想想看，就算看XRD，
particle size的峰（如果有的话）都到了30，40度了，连小角都算不上，呵呵。
TEM |
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S*****n
发帖数: 6055 | 47 首先我得承认我不懂TEM，然后恐怕你也没懂我的意思
我比较熟悉的统计particle size的方法就是chemisorption和EXAFS
这两种方法都需要作一个geometry或者说shape的假设
当然我们可以假设它是spherical的，但是对于lz说得3nm这么小的particle，因为已经
接近原子的大小，spherical的假设已经不精确了（因外表面不再能看成光滑表面），
通常是根据金属的表面性质做一些假设，比如“111面truncated的正20面体”，等等
我想请教的是，如果是用TEM做particle size的statistical analysis，是否也要做同
样的假设？ |
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o*******d
发帖数: 24 | 48 Magnetic nanoparticles with diameters less than 20nm, the magnetization of
the particle fluctuates rapidly from one direction to another due to the
thermal agitation, leaving no net magnetic moment. At this magnetic stage,
the particle is said to be superparamagnetic.
airways 既然做这个,那就多多指教.如果size小于20 nm in diameter,哪种材料的
superparamagnetism最大呢?我们想找最强磁性的.
很好奇,你们做drug delivery, 是用external magnetic field 做site-specific drug
delivery吗?这个真的能行的通吗?那么小的particle不会trap吗?真的能控制他们去哪
里啊? |
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