Scientists in the U.S. have created an artificial sunflower less than 0. 04 inches wide that can bend towards a light source and harvest solar energy. The flowers were found to be about 400 percent more efficient than other equipment, making them promising technology for solar power potentially even as a power source for solar-based spaceships.
The team, led by researchers from the University of California, Los Angeles, was looking to improve. the efficiency of solar cells by modeling after a feature of nature-phototropism. This is where a plant adjusts itself to face the sun, getting the most amount of energy it can get. In a study published in Nature Nanotechnology, the team said it was a ''big challenge''.
However, this problem has now been overcome. The team has developed a polymer(聚合物) that is responsive to being simulated by light, The system, which they have named SunBOT for short, is able to instantly explore and track a light source. It can do this across a range of temperatures without power supply or any human intervention.
The researchers used the polymer to create a ''stem''. Then they placed a material commonly used in solar cells on its top, representing the ''flower''. When the team shone a light at the SunBOTs, the polymer began heating up and shrinking, causing the stem to bend so the flower faced the light.
The researchers tested their artificial sunflowers to see how efficient they were at harvesting solar energy Findings showed they were up to 400 percent more effective than non-phototrophic materials.
The practical applications of SunBOTs are some way off. The study shows a proof of concept, but the technology will need to be scaled up to be used commercially. However, the team is confident it could one day be used a across a broad range of industries.
This work may be useful for solar harvesters signal revere smart windows, self-contained robotics solar sails for spaceships and intelligent energy generation (for example, solar cells and biofuels), the scientific team said.
1.Why do the scientists create the artificial sunflower?
A.To prevent pollution. B.To protect sunflowers.
C.To reuse green energy. D.To warn us of the energy crisis.
2.What can we learn about SunBOTs?
A.SunBOTs are likely to be too limited in future use.
B.There is some time before SunBOTs are put into markets.
C.Scientists are still not sure of the function of SunBOTs.
D.SunBOTts are not efficient, though advanced, in collecting energy.
3.Where can we read such a text?
A.In an education report. B.In a market report.
C.In an experiment report. D.In a science report.
It wasn’t until Friends took off that I was a part of this extraordinary organization, St. Jude. And that was 25 years ago. I am very honored to be a part of St. Jude and I’ve been in love with it ever since.
Right around this time every fall I get to spend the day with a family of St. Jude. I always say it’s the best day of the year and the hardest day of the year. And a few years back I met a little girl named Sawyer. She was seven at the time and I remember she had this pink little dress on and these big angelic eyeballs. The chemo (化疗) had taken all of her hair and she had these tiny little tumors (肿瘤) on her body that she called her “bumps”.
She was just with me the whole time as we ran through the script again and again and again. And at the end of the day after hearing the word repeated over and over again, she looked up at me with those big blue eyeballs and she asked me, “What is cancer?” I just looked at her. Oh! I’m not equipped to answer this question. Here was this little girl who was fighting this deadly disease every single day and she didn’t even know what was the word for it. It was just part of her reality and she was just making the absolute best of it.
That’s what’s unbelievable about these children. Despite everything that they ate up against and as much pain as they’re often in, they are lively. They are joyful. They are fearless. And that’s part of the magic of St. Jude. I’m so honored to support their work because they’re giving children the best care on the planet so that they can regain their childhood, so that they can find their little inner superhero. They’re doing it at no cost so that the families can focus on their little ones, live without worrying about crippling hospital bills and their cutting edge treatments will soon one day find a cure. And that is what every child deserves to know, that they are seen, that they are powerful and are loved, that they deserve a seat at the table, that anything they have to say or any question they have to ask is of value, even if we don’t have all the answers for it.
So thank you very much for recognizing the work of this remarkable organization and for celebrating the power in each and every one of us. Thank you.
1.Which of the following can best describe the little girl named Sawyer?
A.Reliable. B.Humorous.
C.Considerate. D.Innocent.
2.From the text we can infer that St. Jude is home to ________.
A.teachers who are devoted to teaching
B.artists who have achieved great success
C.children who are struck by misfortune
D.students who are academically outstanding
3.The underlined word “crippling” in paragraph 4 probably means _________.
A.upsetting B.inspiring
C.exciting D.weakening
假定你是李华,你的新西兰朋友Peter给你发邮件,表示想了解有关中国谚语(Chinese proverbs)的知识及其学习方法。请你给他回封邮件,内容包括:
1. 中国谚语的由来(人们的智慧和经验,口头传承);
2. 中国谚语的特点(简短而富有意义)
3. 实用的学习方法。
注意:1. 词数100左右;
2. 可以适当增加细节,以使行文连贯。
Dear Peter,
_______________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________
Yours,
Li Hua
假定英语课上老师要求同桌之间交换修改作文,请你修改你同桌写的以下作文。文中共有10处语言错误,每句中最多有两处。每处错误仅涉及一个单词的增加、删除或修改。
增加:在缺词处加一个漏字符号(∧),并在其下面写出该加的词。
删除:把多余的词用斜线( \ )划掉。
修改:在错的词下画一横线,并在该词下面写出修改后的词。
注意:
1. 每处错误及其修改均只限一词;
2. 只允许修改10处,多者(从第11处起)不计分。
In recent years, the sandstorm in the northern part of China has become more and more common natural disaster. The strong wind blows up some sand, making them difficult for people to go out. Sandstorms are caused by a variety of reason. First, in the past people feed a great number of sheep. As a result, the sheep ate so many grass that the land turned into deserts. Second, people were not concerning about protecting forests, and cut down many trees, that caused the loss of soil. When it comes to improve the situation, the government starts to stress at the importance of the environment. I believe final the problem will be solved in the near future.
阅读下面短文,在空白处填入1个适当的单词或括号内单词的正确形式。
While working for a department store in Manhattan, Bob decorated the huge Christmas tree. It turned out to be 1. attracted the shoppers most. He decorated the tree so 2. (beautiful) that many people praised him, 3. (include) the actress Mia Farrow.
Bob mentioned this several times during our first few 4. (discussion). Then one day, he added, “I love decorating for Christmas very much, 5. I have no confidence in making a living at it.” “Why don’t you have a try?” I asked. I explained 6. Bob that starting his own Christmas decorating business matched up well with his desire for the 7. (free) to set his own hours and workload. “You love Christmas, and you love being independent; why not organize your life around those two loves?” Within a year, Bob established a brand as Dr. Christmas, and till now his business 8. (grow) to also providing holiday decorations for movies and television shows.
During my first discussion with Bob neither of us expected 9. (he) future success. So anything is possible! As Bob says, ‘‘Just remember 10. (shape) your life as a game of your own design.”
An old art lover collected many famous paintings. Under his influence, the son also _______ collections. One day news came that the son _______ his life to rescue another soldier in a battle. The old man felt very _______ and he couldn’t cheer himself up even on New Year’s Day. He was thinking of his dear son when someone knocked at the door. The old man _______ it and in came a young man who _______ himself, “I’m a friend of your son. He lost his life to _______ me, so I painted this portrait of your son _______ him.” The old man took hold of this painting with _______. Then he carried the painting upstairs and gently _______ it on the wall. It took the place of a painting by Pablo Picasso, a very ________ Spanish artist.
Several years later, the old man passed away and all his ________ would be sold at an auction (拍卖会). The auctioneer (拍卖师) ________ at a portrait of a young man and announced, “Let’s ________ with this painting. Who would like to pay $50 for it?”
Nobody thought it was a(n) ________ price. People were whispering, “That’s too much for a painting by nobody!”
“$40?”
There was a(n) ________ for a moment. No one responded.
Then a voice came up, “I’m a ________ of the boy. We live in the same block. I saw him growing up, but I’ve got only $ 10. Can I have this portrait with all my money?”
The auctioneer asked ________, “Ten dollars once? Ten dollars twice? Ten dollars three times? Deal!”
The audience were excited that the real auction would begin. ________, the auctioneer concluded, ‘‘The auction is over. According to the ________ will, all the other paintings will ________ the person who buys the portrait.”
1.A.loved B.expected C.sold D.prepared
2.A.lived B.changed C.sacrificed D.shaped
3.A.angry B.worried C.terrified D.sad
4.A.answered B.showed C.locked D.approached
5.A.taught B.introduced C.enjoyed D.believed
6.A.visit B.call C.save D.follow
7.A.in defence of B.in need of C.in favor of D.in memory of
8.A.delight B.patience C.care D.sympathy
9.A.hung B.painted C.dropped D.cleaned
10.A.friendly B.brave C.old D.famous
11.A.clothes B.collections C.letters D.books
12.A.aimed B.glared C.pointed D.laughed
13.A.compare B.play C.struggle D.start
14.A.local B.reasonable C.total D.average
15.A.silence B.argument C.emergency D.sound
16.A.neighbor B.classmate C.companion D.colleague
17.A.coldly B.loudly C.cautiously D.jokingly
18.A.Obviously B.Hopefully C.Unexpectedly D.Fortunately
19.A.son’s B.owner’s C.neighbor’s D.soldier’s
20.A.refer to B.depend on C.focus on D.belong to