网友您好， 请在下方输入框内输入要搜索的题目：

题目内容 （请给出正确答案）
共用题干
Solar Power Without Solar Cells

A dramatic and surprising magnetic effect of light discovered by University of Michigan researchers
could lead to solar power without traditional semiconductor-based solar cells.
The researchers found a way to make an"optical________(51)",said Stephen Rand,a professor in
the departments of Electrical Engineering and Computer Science,Physics and Applied Physics.
Light has electric and magnetic_______(52).Until now,scientists thought the effects of the mag-
netic field were so weak that they could be________(53).What Rand and his colleagues found is that at
the right intensity,when light is traveling through a material that does not_________(54)electricity,the
light field can generate magnetic effects that are 100 million times stronger than previously expected.Under
these circumstances,the magnetic effects develop strength_________(55)to a strong electric effect.
"This could lead to a new kind of solar cell without semiconductors and without absorption to produce
charge separation,"Rand said."In solar cells,the_________(56)goes into a matenal,gets absorbed and
creates heat.Here,we expect to have a very low heat load.Instead of the light being absorbed,energy is
stored in the magnetic moment.Intense magnetization can be induced by intense light and then it is ultimately
capable of providing a capacitive power________(57)."What makes this possible is a previously unde-
tected brand of"optical rectification",says William Fisher,a doctoral student in applied physics.In tradi-
tional optical rectification,light's electric field causes a charge separation,or a pulling_________(58)of
the positive and negative charges in a material.This sets up a voltage,similar to______(59)in a
battery.
Rand and Fisher found that under the right circumstances and in right types of materials,the light's
magnetic field can also create optical rectification.The light must be shone through a________(60)that
does not conduct electricity,such as glass.And it must be focused to an intensity of 10 million watts per
square centimeter. Sunlight isn't this_______(61)on its own,but new materials are being sought that
would work at lower intensities,Fisher said.
"In our most recent paper,we show that incoherent light like sunlight is theoretically almost
_________(62)effective in producing charge separation as laser light is,"Fisher said.
This new_________(63)could make solar power cheaper,the researchers say.They predict that with
improved materials they could achieve 10 percent efficiency in converting solar power to usable energy.That's
equivalent to today's commercial-grade solar cells.
"To manufacture modern solar cells,you have to do. _______(64)semiconductor processing,"
Fisher said."All we would need are lenses to focus the light and a fiber to guide it.Glassworks for
_________ (65).It's already made in bulk,and it doesn't require as much processing.Transparent
ceramics might be even better."

_________(61)
A:bright
B:faint
C:visible
D:intense

参考答案

参考解析
解析：文章第一段提及新的研究发现可能实现不需要传统的半导体太阳能电池而获得太阳 能，因此这里研究者应该是发现了“光学电池”，故选D。
单词application意思为“应用”;component意思为“成分”;resource意思为“资源”; difference意思为“差异，不同”。这里文章所指的是光的组成成分，故选B。
本句的大意为：至今为止，科学家认为光的磁场很弱，因此光的磁效应应该是可被忽略 的，故选B。
单词。 onduct意思为“输送”;produce意思为“生产”;use意思为“使用”;consume意思 为“耗费”。这里指的是光通过不导电的材料，故应选A。
第三段主要探讨电和磁之间的对比，因此最后一句是两者强度的比较。词组be equiva-lent to意思为“和······等同”，符合句意。
根据常识可以判断，这里应该指的是光进人材料，经吸收后产生热量，故应选A。
单词plant作名词意思为“工厂，植物”; source意思为“源头”; equipment意思为“设 备”;line意思为“线路”。根据文章内容可知，这里是指强烈的光照产生强烈的磁化效应，而后 者可以提供一个电容源，故选B。
在本句中“or a pulling...of the positive and negative charges in a material”是对上句charge separation（电荷分离）的解释，词组pull apart意思为“分开，拉开”，故应选C。
单词that常用来代替上文中出现的词语，这里它指代的是voltage，故选C。
由此空下文的“such as glass”可知，这里指的是光线穿过一种材料，故选A。
由下文的“that would work at lower intensities”可知，此处应该指的是光的强度不够高， 所以才寻找适应这一特点的材料，故选D。
此处考查的是as...as结构，这里是把太阳光和激光比较，故选B。
由文章内容可知，本文探讨的是一种科学技术。technology指的是联系到系统、设备和 方法的科学知识，而skill指的是一种技巧，通过培训或训练可习得的本领，故应选B。
由文章倒数第二句中“and it doesn ' t require as much processing”的提示可知，此空指的 是制作现代太阳能电池时需要进行广泛的加工，单词extensive意思为“广泛的，大量的”，符合 句意。
上文Fisher提到所需的是能够聚光的镜片和可以导光的纤维物质，而玻璃制品是可以 同时具备这两种功能的，故选D。
更多 “共用题干 Solar Power Without Solar CellsA dramatic and surprising magnetic effect of light discovered by University of Michigan researchers could lead to solar power without traditional semiconductor-based solar cells.The researchers found a way to make an"optical________(51)",said Stephen Rand,a professor in the departments of Electrical Engineering and Computer Science,Physics and Applied Physics.Light has electric and magnetic_______(52).Until now,scientists thought the effects of the mag-netic field were so weak that they could be________(53).What Rand and his colleagues found is that at the right intensity,when light is traveling through a material that does not_________(54)electricity,the light field can generate magnetic effects that are 100 million times stronger than previously expected.Under these circumstances,the magnetic effects develop strength_________(55)to a strong electric effect."This could lead to a new kind of solar cell without semiconductors and without absorption to produce charge separation,"Rand said."In solar cells,the_________(56)goes into a matenal,gets absorbed and creates heat.Here,we expect to have a very low heat load.Instead of the light being absorbed,energy is stored in the magnetic moment.Intense magnetization can be induced by intense light and then it is ultimately capable of providing a capacitive power________(57)."What makes this possible is a previously unde- tected brand of"optical rectification",says William Fisher,a doctoral student in applied physics.In tradi- tional optical rectification,light's electric field causes a charge separation,or a pulling_________(58)of the positive and negative charges in a material.This sets up a voltage,similar to______(59)in a battery.Rand and Fisher found that under the right circumstances and in right types of materials,the light's magnetic field can also create optical rectification.The light must be shone through a________(60)that does not conduct electricity,such as glass.And it must be focused to an intensity of 10 million watts per square centimeter. Sunlight isn't this_______(61)on its own,but new materials are being sought that would work at lower intensities,Fisher said."In our most recent paper,we show that incoherent light like sunlight is theoretically almost _________(62)effective in producing charge separation as laser light is,"Fisher said.This new_________(63)could make solar power cheaper,the researchers say.They predict that with improved materials they could achieve 10 percent efficiency in converting solar power to usable energy.That's equivalent to today's commercial-grade solar cells."To manufacture modern solar cells,you have to do. _______(64)semiconductor processing,"Fisher said."All we would need are lenses to focus the light and a fiber to guide it.Glassworks for _________ (65).It's already made in bulk,and it doesn't require as much processing.Transparent ceramics might be even better."_________(61)A:brightB:faintC:visibleD:intense” 相关考题
考题 共用题干 The Smog（烟雾）For over a month,Indonesia was in crisis.Forest fires raged out of control as the country suffered its worst drought for 50 years.Smoke from the fires mixed with sunlight and hot dry air to form a cloud of smog.This pollution quickly spread and within days it was hanging over neighbouring countries including Malaysia,Singapore and Thailand.When the smoke combined with pollution from factories and cars,it soon became poisonous（有毒的）.Dangerous amounts of CO became trapped under the smog and pollution levels rose. People wheezed（喘息）and coughed as they left the house and their eyes watered immediately.The smog made it impossible to see across streets and whole cities disappeared as grey soot（烟灰） covered everything. In some areas, water was hosed（用胶管浇）from high-rise city buildings to try and break up the smog.Finally,heavy rains,which came in November,put out the fires and cleared the air. But the environmental costs and health problems will remain.Many people from South-Eastern Asian cities already suffer from breathing huge amounts of car exhaust fumes（汽车排放的废气）and factory pollution. Breathing problems could well increase and many non-sufferers may have difficulties for the first time.Wildlife has suffered too.In lowland forests,elephants,deer,and tigers have been driven out of their homes by smog.But smog is not just an Asian problem.In fact,the word was first used in London in 1 905 to describe the mixture of smoke and thick fog.Fog often hung over the capital. Sometimes the smog was so thick and poisonous that people were killed by breathing problems or in accidents.About 4, 000 Londoners died within five days as a result of thick smog in 1952.The air-pollution index went up to 300 within a few days.A:Right B:Wrong C:Not mentioned
查看答案
考题 共用题干 Travel Across AfricaFor six hours we shot through the barren（荒芜的）landscape of the Karoo desert inSouth Africa. Just rocks and sand and baking sun. Knowing our journey was ending,Daniel and I just wanted to remember all we had seen and done. He used a camera. I used words. I had already finished three notebooks and was into the fourth,a beautiful leather notebook I'd bought in a market in Mozambique.Southern Africa was full of stories and visions.We were almost drunk on sensations,the roaring（咆哮）of the water at Victoria Falls, the impossible silence of the Okavango Delta in Botswana.And then the other things:dogs in the streets,whole families in Soweto living in one room,a kilometre from clean water.As we drove towards the setting sun,a quietness fell over us. The road was empty一we hadn't seen another car for hours.And as I drove,something caught my eye,something moving close enough to touch them,to smell their hot breath. I didn't know how long they had been there next to us.I shouted to Dan:“Look!”But he was in a deep sleep,his camera lying useless by his feet. They raced the car for a few seconds,then disappeared far behind us,a memory of he- roic forms in the red landscape.When Daniel woke up an hour later I told him what had happened.”Wild horses?”he said.”Why didn't you wake me up,Sophia?””I tried. But they were gone after a few seconds.””Are you sure you didn't dream it?””You were the one who was sleeping!””Typical”,he said.”The best photos are the ones we never take.”We checked into a dusty hotel and slept the sleep of the dead.Daniel and Sophia drove slowly through the busy desert.A: RightB: WrongC: Not mentioned
查看答案
考题 We will meet in the office at approximately 3:30 in the afternoon.A:about B:almost C:probably D:rarely
查看答案
考题 共用题干 Energy and Public LandsThe United States boasts substantial energy resources. Federal lands provide a good deal of US energy production,the US Department of the Interior manages federal energy leasing （租赁）both on land and on the offshore Outer Continental Shelf Production from these sources amounts to nearly 30 percent of total annual US energy production.In 2000,32 percent of US oil,35 percent of natural gas,and 37 percent of coal were pro-duced from federal lands,representing 20,000 producing oil and gas leases and 135 producing coal leases. Federal lands are also estimated to contain approximately 68 percent of all undis-covered US oil reserves and 74 percent of undiscovered natural gas.Revenues from federal oil,gas,and coal leasing provide significant returns to US taxpayers as well as State Government. In 1999,for example,$553 million in oil and gas revenues were paid to the US Treasury,and non-India coal leases accounted for over$304 million in revenues,of which 50 percent were paid to State governments. Public lands also play a critical role in energy delivery. Each year , federal land managers authorize（许可）rights of way for transmission lines , rail systems , pipe-lines,and other facilities related to energy production and use.Alternative energy production from federal lands falls behind conventional energy pro-duction , though the amount is still significant. For example , federal geothermal（地热）re-sources produce about 7. 5 billion kilowatt-hours（千瓦时）of electricity per year,47 percent of all electricity generated from US geothermal energy. There are 2,960 wind turbines on public lands in California alone,producing electricity for about 300,000 people. Federal hydropower （水电）facilities produce about 17 percent of all hydropower produced in the United States.Because of the growing US thirst for energy and increasing public unease with depend-ence on foreign off sources,pressure on public lands to meet US energy demand is becoming more intense. Public lands are available for energy development only after they have been evaluated through the land use planning process.If development of energy resources conflicts with management or use of other resources,development restrictions or impact moderation measures may be enforced,or mineral be banned altogether.What is the main idea of this passage?A: Public lands are one of the main sources of revenues.B: Public lands should be developed to ease energy shortage.C: Public lands play an important role in energy production.D: Public lands store huge energy resources for further development.
查看答案
考题 He shifted his position a little,in order to alleviate the pain in his leg.A:control B:ease C:experience D:suffer
查看答案
考题 The brave shopkeeper showed no fear of the armed robber.A:timid B:violentC:courageous D:nervous
查看答案
考题 共用题干 Where Did All the Ships Go?The Bermuda Triangle is one______(51)the greatest mysteries of the sea.In this triangular area between Florida,Puerto Rico and Bermuda in Atlantic,ships and airplanes_(52)to disappear more often than in______(53)parts of the ocean.And they do so______(54)leaving any sign of all accidents or any dead bodies.It is_______(55)that Christopher Columbus was the first person to record strange happenings in the area.His compass stopped working,a flame came down from the sky,and a wave 100 to 200 feet high carried his ship about a mile away. The most famous disappearance in the Bermuda Triangle was the US Naval Air Right 19.______(56) December 5,1945,five bomber planes carrying 14 men______(57)on a training mission from the Florida coast.Later that day,all communications with Flight 19 were lost.They just disappeared without a trace.The next morning,242 planes and 19 ships took part in the largest air-sea search in history.But they found nothing. Some people blame the disappearances______(58)supernatural forces.It is suggested that the ______(59)ships and planes were either transported to other times and places,kidnapped by aliens ______( 60 ) attacked by sea creatures. There are______(61)natural explanations,though.The US Navy says that the Bermuda Triangle is one of two places on earth______（62)a magnetic compass points towards true north______(63) magnetjc north.______(64),planes and ships can lose their way if they don't make adjustments.The area also has changing weather and is known______(65)its high waves.Storms can turn up suddenly and destroy a plane or ship.Fast currents could then sweep away any trace of an accident.52._________A:often B:look C:sometimes D:seem
查看答案
考题 共用题干 第一篇US to Start $3.2 Billion Child Health Study in JanuaryA study that will cost$3.2 billion and last more than two decades to track the health of 100,000 US children from before birth to age 21 will be launched in January,US health officials said on Friday.Officials from the US government's National Institutes of Health said they hope the study,to be conducted at 105 locations throughout the United States,can help identify early-life influences that affect later development,with the goal of learning new ways to treat or prevent illness.The study will examine hereditary（遗传的）and environmental factors such as exposure to certain chemicals that affect health.Researchers will collect genetic and biological samples from people in the study as well as samples from the homes of the women and their babies including air,water,dust and materials used to construct their residences,the NIH said.Officials said more than $200 million has been spent already and the study is projected to cost$3.2 billion."We anticipate that in the long term（从长远来说）,what we learn from the study will result in a significant savings in the nation's health care costs,"Dr. Duane Alexander,who heads the NIH's Eunice Kennedy Shriver National Institute of Child Health and Human Development,told reporters.The study will begin in January when the University of North Carolina and the Mount Sinai School of Medicine in New York start signing up（签订协议）pregnant women whose babies will then be followed to age 21.Some of the early findings will be about factors behind pre-term birth（早产）,which has become more common in recent years,according to Dr. Peter Scheidt of the NIH,who heads the study.The people taking part will be from rural,urban and suburban areas,from all income and educational levels and from all racial groups,the NIH said.Which is NOT true of the people in the study?A:They'll be from various areas.B:They'll be from all income levels.C:They'll be from all educational levels.D:They'll be from all age groups.
查看答案
考题 共用题干 Free Statins with Fast Food could Neutralize Heart RiskFast food outlets could provide statin drugs free of1so that customers can reduce the heart disease dangers of fatty food,researchers at Imperial College London 2in a new study.Statins reduce the3of unhealthy“LDL” cholesterol in the blood. A wealth of trial data has proven them to be highly effective at lowering a person's heart attack4.In a paper published in the American Journal of Cardiology,Dr Darrel Francis and colleagues calculate that the reduction in heart attack risk offered by a statin is5to offset the increase in heart attack risk from6a cheeseburger and drinking a milkshake.Dr Francis,from the National Heart and Lung Institute at Imperial College London,who is the senior author of the study,said:“Statins don't cut out all of the7effects of cheeseburgers and French fries. It's better to avoid fatty food altogether. But we've worked out that in terms of your8of having a heart attack. Taking a statin can reduce your risk to more or less the same9 as a fast food meal increases it.”“It's ironic that people are free to take as many unhealthy condi-ments in fast food outlets as they10,but statins,which are beneficial to heart health,have to be prescribed. It makes sense to make risk-reducing statins available just as easily as the unhealthy condiments that are 11 free of charge. It would cost less than 5 pence per/u>12一not much different to a sachet of sugar.”Dr Francis said.When people engage in risky behaviours like driving or smoking,they're encouraged to take13that lower their risk,like14a seatbelt or choosing cigarettes with filters.Taking a statin is a rational way of15some of the risks of eating a fatty meal.15._________A: increasing B: finding C: lowering D: taking
查看答案
考题 Anderson left the table,remarking that he had some work to do.A: doubtingB: thinkingC: sayingD: knowing
查看答案
考题 共用题干 第二篇The First Navigational LightsIn the New World,navigational lights were probably lanterns hung at harbor entrances.The first lighthouse was put up by the Massachusetts Bay Colony in 1716 on little Brewster Island at the entrance to Boston Harbor. Paid for and maintained by"light dues"levied on ships,the original beacon was blown up in 1776.By then there were only a dozen of so true lighthouses in the colonies. Little over a century later,there were 700 lighthouses.The first lighthouses erected on the west coast in the 1850's featured the same basic new England design:a Cape Cod dwelling with the tower rising from the center or standing close by.In New England and elsewhere,though,lighthouses reflected a variety of architectural styles.Since most stations in the Northeast were built on rocky eminences,enormous towers were not the rule.Some were made of stone and brick,others of wood or metal. Some stood on pilings or stilts;some were fastened to rock with iron rods.Farther south from Maryland through the Florida Keys,the coast was low and sandy. It was often necessary to build tall towers there一massive structures like the majestic Cape Hatteras,North Carolina lighthouse,which was lit in 1870.At 190 feet,it is the tallest brick lighthouse in the country.Notwithstanding differences in appearance and construction,most American lighthouses shared several features:a light,living quarters and sometimes a bell(or,later,a foghorn).They also had something else in common. A keeper and usually,the keeper's family.The keeper' s essential task was trimming the lantern wick in order to maintain a steady,bright flame.The earliest keepers came from every walk of life;they were seamen,farmers,mechanics,rough mill hands and appointments were often handed out by local customs commissioners as political plums.After the administration of lighthouses was taken over in 1 852 by the United states Lighthouse Board,an agency of the Treasury Department,the keeper gradually became highly professional.It may be inferred from the passage that lighthouses in the Northeast did not need high towers because______.A:the coast was straight and unobstructedB:ships there had high mastsC:coastal waters were safeD:the lighthouses were bulb on high Places
查看答案
热门标签
最新试卷