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标题: 10.6 鸡精 [打印本页]

作者: ggmatkiller 时间: 2018-10-6 15:30
标题: 10.6 鸡精
gmat考试日常--未分手
距离上次考有点久了，不知道是不是这个库的原因，gmat的单词真的变难了，好多题读不懂，需要看几遍，导致我最后一篇阅读和几道语法题都没思考！哭泣
语法
1、有考到having done和despite being的正确用法的有两道，不能轻易排除啊
2、有一道题是只有not only, but...没有 also，或者只有also，但语义觉得很奇怪，可如果考虑平行的话还只能选这个只有but那个

阅读
文章好难！但题目不难，应该是我做的不好
最变态的有一篇讲显微镜的变化的
第一段讲说之前的显微镜有什么缺点，然后现在被克服了
第二段讲说现在的这个先进的显微镜的原理【看哭了！你给我中文我都读不懂】
原理是什么忘记了，一堆什么电泳，穿过gap，然后验证原理，最后形成三维立体图
感觉这个完全形不成画面感，所以都记不住
考到细节题了，说进步了的这个显微镜提到了哪些步骤，除了什么
还有作用题，第二段第一句高亮，问作用
还有一道题是问验证原理是什么：好像是什么东西到surface的距离

有一篇讲日本经济的
第一段说日本政策是减少贸易的，对经济有消极影响
第二段反对，说其实经济是增长的了，由于农业什么的原因
然后讲什么忘记了呃呃说了什么进口盐啊什么的

数学q50【整体不难，所以好多都忘记了。。】
1.但这一道题！就那么一句话读了半天不知道问的什么意思
说一群人选A&B，选了A的人里选B的占选A的1/5,在选了B的人里选A的占选B的1/4，问选了A&B的占B的多少
是我脑子抽抽了嘛，不是1/4嘛，这题考的是啥啊，
答案只记住了有个1/3和？/9

作者: 八度余温 时间: 2018-10-6 15:37
啊楼主请问你一篇阅读寂静都没碰到吗

作者: ggmatkiller 时间: 2018-10-6 15:39

八度余温发表于 2018-10-6 15:37
啊楼主请问你一篇阅读寂静都没碰到吗

对一篇都没有伤心

作者: SW13 时间: 2018-10-6 15:44

竟然没有寂静！
不过感谢分享~！
lz加油哇！

作者: 八度余温 时间: 2018-10-6 15:47

ggmatkiller 发表于 2018-10-6 15:39
对一篇都没有伤心

哎摸摸你

作者: Akiii 时间: 2018-10-6 15:55
先谢楼主~数学那道题真的是问占B的占比吗。。如果是问A&B占总体的占比，就是1/9

作者: billyisfragile! 时间: 2018-10-6 15:59

The sex life of flowers - Page 52
https://books.google.com.my/books?id=YGoOAQAAMAAJ

Bastiaan Meeuse, ‎Sean Morris - 1984 - ‎Snippet view - ‎More editions
It concerned the curious little arum lily Arisarum proboscideum, known as the mousetail plant. Its inflorescence has a cylindrical, vertical, but slightly bent-over floral chamber that is completely closed except for an elliptical window that looks
... from the forest floor and entering the floral chamber through the window, is immediately confronted by the appendix of the ... The organ is also off-white in colour so that the overall visual impression it gives is deceptively like that of the ... the cap of a Boletus mushroom. ... claimed that the plants' pollinators were female fungus- gnats — animals that normally breed in decaying mushrooms !

作者: SW13 时间: 2018-10-6 16:04

bzy! 发表于 2018-10-6 15:59
The sex life of flowers - Page 52
https://books.google.com.my/books?id=YGoOAQAAMAAJ

请问这个怎么考古呀?好像看过但忘记是哪个库的~

作者: billyisfragile! 时间: 2018-10-6 16:07

SW13 发表于 2018-10-6 16:04
请问这个怎么考古呀?好像看过但忘记是哪个库的~

https://forum.chasedream.com/thread-1324887-1-1.html

【考古】植物AP授粉

作者: SW13 时间: 2018-10-6 16:16

bzy! 发表于 2018-10-6 16:07
https://forum.chasedream.com/thread-1324887-1-1.html

【考古】植物AP授粉

感谢！！?‍

作者: billyisfragile! 时间: 2018-10-6 16:52
是原文吗？

第一段：现在流行的几乎所有的显微镜，都有一个缺点：好像是通过镜片什么的来对焦，会有折射衍射之类的（defraction?反正就是测量珠峰那篇里面的那个词）。某个科学家，很早之前提出了一个方法来观察测量精密的atom之类的，但是一直无法实现，因为not until recently，才发现了能够达到那么高精度变化的物质（也就是说你可以让他只膨胀或者缩小1微微米那种，这样材料做出来的显微镜精度高）（这句话好像有题）

第一段说到了, 某种光的波长不在人类可以看到的波长之中, 所以某科学家提出了一个理论跟仪器, 但是在那时候无法制作出该仪器第二段说到了, 现在科技的进步导致该仪器已经产生.

Objects smaller than the wavelengths of visible light are a staple of contemporary science and technology. Biologists study single molecules of protein or DNA; materials scientists examine atomicscale flaws in crystals; microelectronics engineers lay out circuit patterns only a few tens of atoms thick. Until recently this minute world could be seen only by cumbersome, often destructive methods such as electron microscopy and X-ray diffraction. It lay beyond the reach of any instrument as simple and direct as the familiar light microscope.

A family of new microscopes opens this realm to direct observation. The devices can map atomic and molecular shapes, electrical, magnetic and mechanical properties and even temperature variations at a higher resolution than ever before, without the need to modify the specimen or expose it to damaging, high-energy radiation. The achievement seems implausible. More than 100 years ago, after all, the German physicist and lensmaker Ernst Abbe described a fundamental limitation of any microscope that relies on lenses to focus light or other radiation: diffraction obscures details smaller than about one half the wavelength of the radiation.

第一段：光学显微镜有人说不给力，因为有折射什么会影响，然后1956年（大概是这时候）有人提出了一种理论可以解决这个问题，但还没办法通过这个理论制作新的显微镜，因为缺少能够精确定位的仪器还是技术来着（失忆了。。。但这里有题，看到文章很容易locate）

The new microscopes-typified by  the scanning tunneling microscope, for which Gerd Binnig and Heinrich  Rohrer of the IBM Zurich Research Laboratory received a Nobel prize in 1986-overcome this Abbe barrier with ease. The principle by which they  do so was first described in 1956. In that year]. A. O'Keefe, then of the U. S. Army Mapping Service, proposed a microscope in which light would  shine through a tiny hole in an opaque  screen, illuminating an object directly  in front of the screen. Light transmitted through the specimen or reflected  back through the hole would be recorded as the sample was scanned  back and forth. O'Keefe pointed out  that the resolution of such a "scanning near-field microscope" would be  limited only by the size of the hole and  not by the wavelength of the light. In  principle the device could make superresolving images-images showing  details smaller than half a wavelength.

O'Keefe acknowledged that technology capable of positioning and  moving an object with the needed precision did not exist. By resorting to  long-wavelength radiation, however,  Eric Ash of University College, London,  adopted the O'Keefe strategy in 1972  to circumvent the Abbe barrier. He  passed microwave radiation at a wavelength of three centimeters through a  pinhole-size aperture and scanned an  object in front of it to record an image  with a resolution of 150 microns-one
two-hundredth of a wavelength.

By that time, means of controlling  sample position and movement with  the precision needed to surpass the  resolution of a conventional light microscope were becoming available. In  the same year as Ash's demonstration,  Russell D. Young of the National Bureau of Standards succeeded in manipulating objects in three dimensions with a precision of about a nanometer (a billionth of a meter). He relied  on piezoelectrics-ceramic materials that change size ever so slightly when  an electrical potential across the material is changed. Piezoelectric controls  opened the way to the development,  in 1981, of the supreme example of  a scanning near-field microscope, the  scanning tunneling microscope, or  STM [see "The Scanning Tunneling Microscope," by Gerd Binnig and Heinrich Rohrer; SCIENTIFIC AMERICAN, August, 1985).

第二段：说这个新型显微镜“XXX tunnelling microscope”的工作原理，这个显微镜就是通过control（大概就是支架）来控制一个probe，由于这种材料能够精密控制大小，这样能够让那个probe尽可能的贴近标本的表面，但是不接触。这样足够近的情况下，两边如果有电压，就会产生一个"tunnel"，实际就是两者的gap中产生电流了。（有题问tunnel是什么，就是the nature of currents between probe and specimen）这个电流的强度，是由probe和标本中物质粒子的距离决定的，probe会在整个标本上移动，当他经过一堆atom上时，电流就强，当他经过atom之间的相对空白的地方（想象两颗石子中间的空当），电流就弱，所以根据电流大小就可以知道这个标本的表面的形状。

In the STM the "aperture" is a tiny tungsten probe, its tip ground so fine that it may consist of only a single atom and measure just .2 nanometer in width. Piezoelectric controls maneuver the tip to within a nanometer or two of the surface of a conducting specimen-so close that the electron clouds of the atom at the probe tip and of the nearest atom of the specimen overlap. When a small voltage is applied to the tip, electrons "tunnel" across the gap, generating a minuscule tunneling current. The strength of the current is exquisitely sensitive to the width of the gap; typically it decreases by a factor of 10 each time the gap is widened by .1 nanometer-half the diameter of an atom.

X and y piezoelectric controls (which govern motion in the two dimensions of a plane) move the probe back and forth across the specimen surface in a raster pattern, its parallel tracks separated by perhaps a fraction of a nanometer. If the probe maintained a steady height, the tunneling current would fluctuate dramatically, increasing as the tip passed over bumps such as surface atoms and falling to nothing as it crossed gaps between atoms. Instead the probe moves up and down in concert with the topography. A feedback mechanism senses the variations in tunneling current and varies the voltage applied to a third, Z, control. The Z piezoelectric moves the probe vertically to stabilize the current and maintain

作者: 橘子太软 时间: 2018-10-6 17:39

bzy! 发表于 2018-10-6 16:07
https://forum.chasedream.com/thread-1324887-1-1.html

【考古】植物AP授粉

Mark一下！

作者: vegetableshu 时间: 2018-10-7 06:58

Akiii 发表于 2018-10-6 15:55
先谢楼主~数学那道题真的是问占B的占比吗。。如果是问A&B占总体的占比，就是1/9
...

怎么算的呀，请问

作者: Cris7 时间: 2018-10-7 09:20

Akiii 发表于 2018-10-6 15:55
先谢楼主~数学那道题真的是问占B的占比吗。。如果是问A&B占总体的占比，就是1/9
...

占总体的比不是1/8吗？

作者: OLIVIAHAN777 时间: 2018-10-7 20:23
感谢分享！

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