Watching Microcurrents Flow

　　We can now watch electricity as it flows through even the tiniest circuits. By scanning the magnetic field generated as electric currents flow through objects, physicists have managed ____1____. The technology will allow manufacturers to scan microchips for faults, as well as revealing microscopic defects in anything from aircraft to banknotes.

　　Gang Xiao and Ben Schrag at Brown University in Providence, Rhode Island, visualize the current by measuring subtle changes in the magnetic field of an object and ____2____.

　　Their sensor is adapted1 from an existing piece of technology that is used to measure large magnetic fields in computer hard drives.2”We redesigned the magnetic sensor to make it capable of measuring very weak changes in magnetic fields,” says Xiao.

　　The resulting device is capable of detecting a current as weak as 10 microamperes, even when the wire is buried deep within a chip, and it shows up features as small as 40 nanometers across.

　　At present, engineers looking for defects in a chip have to peel off the layers and examine the circuits visually; this is one of the obstacles ____3____. But the new magnetic microscope is sensitive enough to look inside chips and reveal faults such as short circuits , nicks in the wires or electro migration ― where a dense area of current picks up surrounding atoms and moves them along. “It is like watching a river flow,” explains Xiao.

　　As well as scanning tiny circuits, the microscope can be used to reveal the internal structure of any object capable of conducting electricity.3 Fpr example, it could look directly at microscopic cracks in an aeroplane’s fuselage, ____4____. The technique cannot yet pick up electrical activity in the human brain because the current there is too small, but Xiao doesn’t rule it out4 in the future. “I can never say never,” he says.

　　Although the researchers have only just made the technical details of the microscope public, it is already on sale,5 from electronics company Micro Magnetics in Fall River, Massachusetts. It is currently the size of a refrigerator and takes several minutes to scan a circuit, but Xiao and Schrag are working ____5____.

　　詞匯：

　　circuit 電路 scan 掃描;細看

　　magnetic 磁鐵的;磁石的 subtle 精巧的;細微的

　　visualize 使……形象化;使……具體化 dense 密集的;稠密的

　　sensor 感應器

　　注釋：

　　1.is adapted：(使)適應。作不及物動詞時的用法是：“adapt to +名詞性成分”，如：The young man from the countryside adapted well to life in the big city.這個農村青年很能適應大城市的生活。易混的詞：(1)adopt采取;采納(及物動詞)。adopt a positive attitude采取積極的態度。(2)adept熟練的;擅長的(形容詞)。be adept in(或at)，如：This boy is adept in/at figures.這個男孩擅長計算。

　　2.computer hard drives：計算機硬盤

　　3.conducting electricity：導電

　　4.rule ... out：排除……的可能性。又如：The police have ruled out murder in the case of the girl’s death.警方在姑娘死亡案中已排除他殺的可能性。

　　5.on sale：出售;上市。如：Will the new product be on sale next month?這種新產品下月會上市嗎?

　　練習：

　　A　to shrink it to the size of a desktop computer and cut the scanning

　　B　to making chips any smaller

　　C　to take tiny chips we require

　　D　to picture the progress of the currents

　　E　converting the information into a color picture showing the density

　　F　faults in the metal strip of a forged banknote or bacteria in a water

　　答案與題解：

　　1.D　manage to+v.是“設法做成”的意思。picture在此是動詞，“to picture the progress of the cuixents”意為“繪出電流運行圖”。

　　2.E　by在句中引導兩個在句法結構上并列的分詞短語：一個是measuring subtle changes in the magnetic field of an object，另一個是converting the information into a color picture showing the density of current at each point。convert ... into ... 的意思是“把……轉變為……”。

　　3.B　“obstacle to+名詞性成分”的意思是“……的障礙”。

　　4.F　faults in the metal strip of a forged banknote和bacteria in a water sample與前文中的microscopic cracks in an aeroplane’s fuselage在意思上是并列的關系。

　　5.A　這部分所說的體積的減小和所需時間的縮短恰好與前半句中提到的冰箱大小的體積和所需數分鐘的時間形成了對比。

　　譯文：觀察微電流流程

　　現在電流流過哪怕是最窄的電路時我們都能看到。物理學家們通過掃面電流物體時產生的磁場而繪出電流運行圖。這種技術可以使制造者掃面微芯片上的錯誤，同時可以找出從飛行器到鈔票等物上的細微缺陷。

　　羅德島州普羅維登斯的布朗大學Gang Xiao和Ben Schrag通過測量一個物體的磁場內的細微變化并把信息轉化成顯示每一點電流強度的彩色圖片而使電流顯現。

　　他們的傳感器是由現有的用于測量電腦硬盤的大磁場的技術配件改造而成的。Xiao說：“我們重新設計了磁性傳感器使它能夠測量磁場中非常微弱的變化?！?/P>

　　重新設計完的裝置能夠探測微弱到10微安培的電流，甚至是當癲癇深藏在芯片中的時候，它也能夠顯示出直徑只有40納米長的圖案。

　　目前，那些在芯片中尋找缺點的工程師們必須要剝掉表層目測電路。這是使芯片變得更小的阻礙之一。但是新的磁性顯微鏡非常敏感，能夠看到芯片內部，找出短路、電線的裂痕或電遷移等缺點，電遷移是指電流強大的區域吸引周圍的原子并使它們移動。Xiao解釋說：“那就像看著一條河水在流淌?！?/P>

　　顯微鏡不僅能夠掃描微笑的電路，還可以用于找出能夠導電的物體的內部結構。例如，它能夠直接看到飛機機身上的極細微的裂縫、偽鈔的金屬條上的卻掉或者水樣中的細菌。這種技術還不能提取人腦中的電活動，因為那里的電流太小了，但是Xiao并沒有排除將來實現它的可能。他說：“網永遠不會說永遠不能。”

　　盡管研究者剛剛公開電顯微鏡的技術細節，位于馬薩諸塞州Fall River的微磁電子設備公司已經在出售它了。目前它大約像冰箱那么大，而且要用幾分鐘掃描一個電路，但是Xiao和Schrag正在努力使它縮小到臺式計算機那么大，把掃描時間縮短到30秒。