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____.

注釋：

1．is adapted：（使）適應(yīng)。作不及物動(dòng)詞時(shí)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(gè)農(nóng)村青年很能適應(yīng)大城市的生活。易混的詞：（1）adopt采取；采納（及物動(dòng)詞）。adopt a positive attitude采取積極的態(tài)度。（2）adept熟練的；擅長(zhǎng)的（形容詞）。be adept in（或at），如：This boy is adept in/at figures.這個(gè)男孩擅長(zhǎng)計(jì)算。

2．computer hard drives：計(jì)算機(jī)硬盤

3．conducting electricity：導(dǎo)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(chǎn)品下月會(huì)上市嗎？

練習(xí)：

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(shè)法做成”的意思。picture在此是動(dòng)詞，“to picture the progress of the cuixents”意為“繪出電流運(yùn)行圖”。

2．E　by在句中引導(dǎo)兩個(gè)在句法結(jié)構(gòu)上并列的分詞短語(yǔ)：一個(gè)是measuring subtle changes in the magnetic field of an object，另一個(gè)是converting the information into a color picture showing the density of current at each point。convert ... into ... 的意思是“把……轉(zhuǎn)變?yōu)椤薄?/p>

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(guān)系。

5．A　這部分所說(shuō)的體積的減小和所需時(shí)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(shù)分鐘的時(shí)間形成了對(duì)比。

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（責(zé)任編輯：vstara）

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