2015年考研英語閱讀理解工學(xué)類文章練習(xí)37套(5)_跨考網(wǎng)
Many people think that information technology and biotechnology will rule the 21st century. Robert Birge, a chemist at the University of Connecticut, is trying to combine them, by making computer memories out of protein.
The protein in question is bacteriorhodopsin (bR), a molecule that undergoes a structural change when it absorbs light. By using genetic engineering to tweak wild bR from a bacterium called Halobacterium salinarum, Dr Birge and his colleagues have made a variety of the molecule that they claim is well-suited to act as an element of a computer's memory. Hit with a green light, it adopts one shape. Hit subsequently with a red light, it twists itself into another. Then, if hit with blue light, it resets itself into its original state.
To make a memory from the protein, Dr Birge suspends elements made from it in a transparent plastic cube known as a cuvette. A pair of lasers arranged at right angles to one another write data into the cuvette by shining in turn on “slices” through the plastic matrix. The first laser, which produces green light, sweeps the whole cuvette, causing its protein contents to take on a shape that (in binary code) is designated as “zero”。 The second laser, which produces red light, then stimulates particular sites to take the second shape. This corresponds to “one” in binary code. Once the lasers are switched off, data recorded this way will, according to Dr Birge, remain stable for more than 12 years.
To read the stored data, a low-powered red laser is shone slice by slice through the cuvette. This does not disturb the conformation of the protein molecules; but those in state “zero” absorb light at this wavelength. A machine placed behind the cuvette detects this absorption pattern and translates it into the appropriate string of ones and zeroes. Once the contents have been read into a more conventional storage device, the cuvette can be wiped clean and reset by illuminating it with a blue laser.
Dr Birge says that each cuvette can now hold about seven gigabytes of data (a small laptop computer might have about this much space on its hard drive)。 He hopes to boost that figure to ten gigabytes by finding a better-performing variety of the protein. Only those with deep pockets, however, could afford the $25,000 cost of each device.
Luckily for Dr Birge, the deep-pocketed American air force thinks that bR cuvettes could be a good way to equip its aircraft and satellites with light, high-density devices to store the mountains of images collected during reconnaissance missions. A protein-based memory is particularly suitable for this, because the bR molecule is robust enough to withstand the barrage of radiation from space that wreaks havoc on conventional magnetic-memory devices operating at high altitude.
注(1):本文選自Economist; 12/22/2001, p94, 1/2p, 1c;
注(2):本文習(xí)題命題模仿對象2001年真題Text 3(第一題到第三題); 2004年真題Text 1(第四題和第五題);
1. What is the passage mainly about?
[A]What will rule the 21st century.
[B]How bacterial protein can be used in computers.
[C]What we can get from bacterial protein.
[D]How to make bacterial protein.
2. The application of bR turns out to be___________.
[A]very trustworthy
[B]rather superficial
[C]somewhat contradictory
[D]quite encouraging
3. The basic problem of applying bR to computer lies in ____________.
[A]limited space on hard drive
[B]its complexity
[C]its high price
[D]its limited users
4. Which of the following is not the advantage of bR?
[A]Working at higher altitude.
[B]Light weight.
[C]High density.
[D]Safe from strong radiation.
5. Which of the following is true according to the text?
[A]bR has a wide variety of application in life.
[B]The protein molecules have stable characteristics.
[C]The data recorded with bR can be kept for a long time.
[D]The new device will replace conventional storage device.
答案:BDCAC
2022考研初復(fù)試已經(jīng)接近尾聲,考研學(xué)子全面進(jìn)入2023屆備考,跨考為23考研的考生準(zhǔn)備了10大課包全程準(zhǔn)備、全年復(fù)習(xí)備考計(jì)劃、目標(biāo)院校專業(yè)輔導(dǎo)、全真復(fù)試模擬練習(xí)和全程針對性指導(dǎo);2023考研的小伙伴針也已經(jīng)開始擇校和復(fù)習(xí)了,跨考考研暢學(xué)5.0版本全新升級,無論你在校在家都可以更自如的完成你的考研復(fù)習(xí),暑假集訓(xùn)營帶來了院校專業(yè)初步選擇,明確方向;考研備考全年規(guī)劃,核心知識點(diǎn)入門;個(gè)性化制定備考方案,助你贏在起跑線,早出發(fā)一點(diǎn)離成功就更近一點(diǎn)!
考研院校專業(yè)選擇和考研復(fù)習(xí)計(jì)劃 | |||
2023備考學(xué)習(xí) | 2023線上線下隨時(shí)學(xué)習(xí) | 34所自劃線院??佳袕?fù)試分?jǐn)?shù)線匯總 | |
2022考研復(fù)試最全信息整理 | 全國各招生院校考研復(fù)試分?jǐn)?shù)線匯總 | ||
2023全日制封閉訓(xùn)練 | 全國各招生院??佳姓{(diào)劑信息匯總 | ||
2023考研先知 | 考研考試科目有哪些? | 如何正確看待考研分?jǐn)?shù)線? | |
不同院校相同專業(yè)如何選擇更適合自己的 | 從就業(yè)說考研如何擇專業(yè)? | ||
手把手教你如何選專業(yè)? | 高校研究生教育各學(xué)科門類排行榜 |
相關(guān)推薦
跨考考研課程
班型 | 定向班型 | 開班時(shí)間 | 高定班 | 標(biāo)準(zhǔn)班 | 課程介紹 | 咨詢 |
秋季集訓(xùn) | 沖刺班 | 9.10-12.20 | 168000 | 24800起 | 小班面授+專業(yè)課1對1+專業(yè)課定向輔導(dǎo)+協(xié)議加強(qiáng)課程(高定班)+專屬規(guī)劃答疑(高定班)+精細(xì)化答疑+復(fù)試資源(高定班)+復(fù)試課包(高定班)+復(fù)試指導(dǎo)(高定班)+復(fù)試班主任1v1服務(wù)(高定班)+復(fù)試面授密訓(xùn)(高定班)+復(fù)試1v1(高定班) | |
2023集訓(xùn)暢學(xué) | 非定向(政英班/數(shù)政英班) | 每月20日 | 22800起(協(xié)議班) | 13800起 | 先行階在線課程+基礎(chǔ)階在線課程+強(qiáng)化階在線課程+真題階在線課程+沖刺階在線課程+專業(yè)課針對性一對一課程+班主任全程督學(xué)服務(wù)+全程規(guī)劃體系+全程測試體系+全程精細(xì)化答疑+擇校擇專業(yè)能力定位體系+全年關(guān)鍵環(huán)節(jié)指導(dǎo)體系+初試加強(qiáng)課+初試專屬服務(wù)+復(fù)試全科標(biāo)準(zhǔn)班服務(wù) |