TEM复染

一、布拉格定律

代数形式2dHKLsin(θ)=λ（近似2dHKLθ=λ）， 或矢量形式 KD?KI?ghkl

二、衍射束振幅计算

三、TEM基本结构 从上之下

1. 电子枪：分类——热发射、场发射，三极结构，哪三极，三极的电位高低 2. 电磁透镜

物镜：依靠高尺寸精度的极靴及其高装配精度，获得高轴对称高强度非均匀磁场，以使物镜具有高分辨率，物镜的分辨率决定了整个电镜的分辨率。

概念：电磁透镜的球差、像散、色差、景深、焦长

孔径半角、散射角。注意：电子沿透镜光轴入射时，散射角大于孔径半角的电子不能用于TEM成像。 孔径半角对球差、像散、色差、景深、焦长的影响规律

四、TEM拍摄图像（高倍）与衍射花样的光路示意图

五、衍射花样标定：

下图为钢铁材料的花样，请对所有衍射斑点进行晶面指数标定，格式为（例）：(110)γ，(112)α。写出晶带轴指数，格式为（例）：B=[011]γ。下标α和γ分别代表铁素体相和奥氏体相。 附铁素体与奥氏体的晶面间距表。

1

六、TEM明场像、普通暗场像、中心暗场像成像光路图（需要显示选区光阑和物镜光阑的位置） 2

七、给出试样上各晶区（面心立方）的选区衍射花样，画出图示物镜光阑所套位置的图像示意图（不插入选区

TEM 4

PART VI WRITING

Read carefully the following excerpt on term-time holiday arguments in the Uk, and then write your response in NO LESS THAN 200 words, in which you should: ? Summarize the main message of the excerpt, and then

? Comment on whether parents should take children out of school for holiday during term

time in order to save money.

You should support yourself with information from the excerpt.

Marks will be awarded for content relevance, content sufficinecy, organization and language quality, failure to

A B C D E F G H I J K L M N O P Q R S T U V W x A B C D E F G H I J K L M N O P Q R S T U V W x

abandon abide

ability abolish abrupt

absence absent

absolute absolutely absorb

absorption abstract absurd abundance abundant abuse academic accent accept acceptable

No.001

vt.丢弃；放弃，抛弃 vt.(by)坚持,遵守 vt.忍受

n.能力；能耐，本领 vt.废除，取消 adj. 突然的,意外的;(举止、言谈等)唐突的，鲁莽的

n.缺席，不在场缺乏 a.(from)不在场的；缺乏的漫不经心的 a.绝对的；纯粹的 ad.完全地；绝对地 vt.吸收；使专心 n.吸收；专注

adj.抽象/深奥的n.摘要提要v.提(抽取) a.不合理的，荒唐的 n.丰富，充裕

a.(in)丰富的大量的 vt.滥用虐待 n.滥用 a. 学院的；学术的 n.口音，腔调；重音 vt.vi.接受；同

TEM 4阅读训练（2）

Passage 1 Remember the drinking fountain, that once ubiquitous (到处存在的), and free, source of H2O? It seems quaint now. Instead, bottled water is everywhere, in offices, airplanes, stores, homes and restaurants across the country. We consumed over eight billion gallons of the stuff in 2006, a 10% increase from 2005. It’s refreshing, calorie-free, convenient to carry around, tastier than some tap water and a heck of a lot healthier than sugary sodas. But more and more, people are questioning whether the water, and

TEM4专四阅读理解专项练习

A Wise Man

He was a funny looking man with a cheerful face and a good-natured talker. He was described by his student, the great philosopher Plato, as \man was condemned to death for his beliefs.

The man was the Greek philosopher, Socrates, and he was condemned for not believing in the recognized god and for corrupting young people. The second charge stemmed from his association with numerous young men who came to Athens from all over the civilized world to study under him.

Socrates' method of teaching was

1998—2012年TEM-4考试语法分类

*******倒装句******

1. A：Mother．you promised to take me out． B：Well_____(2012年63题) A. so I did! B. so did I. C. so I do! D. so do I 2. Little____ about her own safety, though she herself was in great danger. (2009年59题) A she cared B she may care C may she care D did she care 3. It is going to be fine tomorrow._____ (2009年58题) A. So is it B So it is C So it does D So does it 4. ____ dull he may be, he is certainly a very successful top executive. (2006年51题) A. Although B. Whatever

TEM 4阅读训练（2）

Passage 1 Remember the drinking fountain, that once ubiquitous (到处存在的), and free, source of H2O? It seems quaint now. Instead, bottled water is everywhere, in offices, airplanes, stores, homes and restaurants across the country. We consumed over eight billion gallons of the stuff in 2006, a 10% increase from 2005. It’s refreshing, calorie-free, convenient to carry around, tastier than some tap water and a heck of a lot healthier than sugary sodas. But more and more, people are questioning whether the water, and

Many people enjoy very active, physical recreation like sports, camping and fishing. Other people prefer to spend their leisure time participating in more intellectual activities like reading, listening to music, collecting stamps or watching films. Write an essay of about 400 words, comparing a physical pastime with an intellectual one and explain why you think one is better than the other to a person of your age.

In the first part of your writing you should present your thesis statement, and in the second part you should

专四新题型样题

TEM4 SAMPLE SCRIPT

(部分〉

PARTI

DICTATION

Li sten to the following passage. Altogether the passage will be read to you four times. During the first reading, which will be done at normal speed, Iisten and try to understand the meaning. For thesecond and third readings, the passage will be read sentence by sentence, or phrase by phrase, with intervals of 15 seconds. The last reading will be done at nonnal speed again and during this time you should check your work. You will then be given 1 minute to check through your work o

TEM TE TM模的区别

在自由空间传播 的均匀平面电磁波（空间中没有自由电荷，没有传导电流），电场和磁场都没有和波传播方向平行的分量，都和传播方向垂直。此时，电矢量E，磁矢量H和传播方 向k两两垂直。只是在这种情况下，才可以说电磁波是横波。沿一定途径（比如说波导）传播的电磁波为导行电磁波。根据麦克斯韦方程，导行电磁波在传播方向上 一般是有E和H分量的。光的传播形态分类：根据传播方向上有无电场分量或磁场分量，可分为如下三类，任何光都可以这三种波的合成形式表示出来。

1、TEM波：在传播方向上没有电场和磁场分量，称为横电磁波。若激光在谐振腔中的传播方向为z方向，那么激光的电场和磁场将没有ｚ方向的分量！ 实际的激光模式是准TEM模，即允许Ez、Hz分量的存在，但它们必须<<横向分量，因为较大的Ez意味着波矢方向偏离光轴较大，容易溢出腔 外，所以损耗大，难于形成振荡。

2、TE波(即是物光里的s波)：在传播方向上有磁场分量但无电场分量，称为横电波。在平面光波导(封闭腔结构)中，电磁场分量有Ey, Hx, Hz，传播方向为ｚ方向。

3、TM波(即是物光里的p波)：在传播方向上有电场分量而无磁场分量，称为横磁波。在平面光波导(封闭腔结构)中，电磁场分量有Hy, Ex, Ez，传播方向为ｚ方向。

微波工程、电磁场理论等课程中有关于TEM