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EPR电子顺磁共振教程


Purcell
1955年 1966年 1981年 1989年 W.E. Lamb, P. Kusch A. Kastler N. Bloembergen N.Fቤተ መጻሕፍቲ ባይዱ Ramsey 1964年 1977年 1983年 1991年 C.H. Townes J.H. Van Vleck H. Taube R.R. Ernst
EPR—研究对象三
Glass-fiber
Ionomer Conducting polymer Degradation Polymerization
Liquid crystal LB membrane Organomagnetic Conducting materials
Immunoassay Drug detection
C Ph2
两个碳上各有一个未偶电子,且被两个苯环隔开,相
互作用很弱,是一个典型的双基,可以用EPR研究它。
4、顺磁性分子(含有未成对电子 的分子)
如:NO,NO2,O2等分子,本身就具有未
成对电子,是顺磁性的。
EPR—研究对象三
EPR—研究对象三
分子轨道理论可以解释。如:O2分子:
2O [(1S)2 (2S)2 (2P)4] O2 [KK(σ2s)2(σ*2s)2(σ2p)2(πy2p)2(πz2p)2(πy*2p)1(πz*2p)1]
EPR—研究对象三
再如:蒽分子它本身是逆磁性分子
An + K (真空无水条件)
An- + K+ (用四氢呋喃作溶剂)
An + H2SO4 (98%)
An+
EPR—研究对象三
其它相关的自由基化学:
EPR—研究对象三
EPR—研究对象三
EPR—研究对象三
EPR—研究对象三
EPR—研究对象三
酒类:啤酒主要性能指标之一,lag time Beer-Flavor Stability
A、快速冷冻法
如:低温检测(液氮、液氦温度) B、 自旋捕获法(Spin Trapping) 用捕获剂与自由基加合,生成长寿命稳定的自由基, 然后对其进行研究。 C、 连续流动法
使用连续流动样品池,如:CIDEP的研究大多用此法。
EPR—研究对象三
EPR的优点与缺点:
优点:1、EPR是观察自由基等顺磁性物质的一种
that have unpaired electrons.
It is also often
called ESR, Electron Spin Resonance, ESR.
2004研究生课程— EPR
因磁共振的杰出贡献而获得诺贝尔奖科学家
1944年 I.S. Rabi 1952年 F. Bloch, E.M.
V23(4S23d3) V5+(3d 0)无EPR信号 V4+(3d 1)有EPR信号 Mn25(4S23d5) Mn5+ (3d 0)无EPR信号 Mn2+ (3d 5)有EPR信号
EPR—研究对象三
过渡金属和稀土元素的EPR谱线特点: 谱线复杂且谱线大多很宽,理论处理也较困难。 原因: 1、离子并非以自由形式存在,处在由配位体组成的 晶场中;
EPR—研究对象三
PBN-OH加合物的ESR谱线:
EPR—研究对象三
化妆品:如SOD,抗氧剂(防晒油等); 烟草:清除烟草烟气自由基—有害成分;
如何提香、降害?—烟草制品的改进方向。
3、双基或多基
这类化合物含有两个或两个以上未成对电
子,且它们相距甚远,相互作用也很弱。
EPR—研究对象三
例如: Ph2C
Raymond snubbed by Nobel Committee because he is beloved by God? Godless science shits on a saint.
I don't know. Perhaps Raymond deserves the prize. MRI was first attempted by him but his results were pretty much useless. His original paper has been discredited by follow up research. I personally see no conflict between science and spiritualism, but putting a Christian God as the head of the universe is tacky in my opinion. Teaching that there has been no evolution, that Genesis contains a literal cosmology, well that isn't science in any sense I understand.
Now the controversy is Was
I'll let God decide whether Raymond gets his Nobel or not…..
2004研究生课程— EPR
本讲座的主要内容:
一、 电子顺磁共振的研究对象 二、 电子顺磁共振的基本原理
三、 电子顺磁共振波谱 四、 电子顺磁共振仪
2、电子处在离子的d壳层中,它们的自旋运动和轨运
动间有很强的“自旋—轨道偶合作用”。
EPR—研究对象三
7、半导体中的空穴或电子
也可用EPR来作定量研究。
8、晶格缺陷
如:V心、F心。
9、其它
EPR在剂量学、年代学上的运用:
C14(几万年)、热释光(几十万年)、EPR(上百万年)。
EPR—研究对象三
5、三重态分子
这类化合物分子轨道上也有两个未偶电子,但其与双基 不同,这两个电子彼此相距很近,有很强的相互作用。有两类: 1、激发三重态;如:萘激发三重态;
2、基态就是三重态分子如:氧分子。
6、过渡金属和稀土元素
EPR—研究对象三
EPR—研究对象三
过渡金属、稀土元素具有未充满的3d,4d,5d及 4f壳层,核外有一个或一个以上的未成对电子。
科学出版社 ,1987
4、陈贤镕,电子自旋共振实验技术,科学出版社 ,
1986
5、石津和彦 等,实用电子自旋共振简明教程(生命
科学专业适用),南开大学出版社,1992
6、张建中等,磁共振教程,中国科大出版社 ,1996
电子顺磁共振(EPR)
历史:
2004研究生课程— EPR
1945年,前苏联物理学家,柴伏依斯基/或称扎伏伊
EPR—研究对象三
一、 电子顺磁共振的研究对象
Application Fields of ESR Spectroscopy
Magnetic substance photo-translation Transition metal ion Catalyst Metal complex Teeth, Bone Shell, Coral Quartz, Aging Radiation defects Coal, Oil Erosion Spin label Fluidity SOD activity Aging, Cancer Co-enzyme Vitamin C, E, K Combustion Spin trap Active oxygen Enzyme
2002年
K. Wü thrich
2003年
P.C. Lauterbur,
S. P. Mansfield (到今年为止)
Nobody loves Raymond (Damadian)
The Nobel Prize in Medicine did NOT go to Raymond Damadian, and he is mad as hell. Mad enough to take out advertisements in the NY Times and the Washington Post. ……. (the way it is still done today). Raymond wasn't detoured he thinks outside the box. So he did some experimentation gathered up a set of data and published a nice bit of original work. He still didn't have a machine that we would call a modern MRI. The data his machine produced was not a pretty picture, nor could his results and conclusions be verified. But he did publish that paper. It got others thinking and involved with MRI. Other people who actually produced practical working MRI devices. Our boy Ray couldn't get his machine to work very well, for years he couldn't. He did however get a patent. With that patent he spent years chasing GE Medical Systems through the courts. He and his lawyers got over $100 million dollars from them in the end. His company eventually did produce an MRI device that could be sold on the market. My title is misleading there is a group of individuals who love Raymond. It is the Creation Science community.
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