The 2014 Nobel Prize in physics went to three scientists who gave lighting a big change by inventing blue LED lights. A big change in lighting efficiency is under way around the world.
Save and green
LEDs use less energy than other forms of lighting. A typical LED bulb(灯泡) can produce around 83 lumens per watt — a measure of how much brightness you can get from a unit of electrical power — much more efficient than other lighting facilities.
LEDs produce light by passing electric current through a semiconductor, while traditional bulbs pass current through a wire. The wasted heat energy is chiefly why traditional bulbs are so much less efficient.
LEDs also last about 30 times longer than traditional bulbs, and many LED bulb products promise up to 25,000 hours of use — more than 17 years if you used one for about four hours a day.
Lighting the world
The lighting application is not only in homes. LEDs are also being used for street lights, public holiday and decorative displays, commercial buildings, and other large energy users.
Car lighting is another application where LEDs are making progress. LEDs used to be used only for daytime running lights, but now many new cars have LED headlights for night-time use.
LEDs also hold promise for bringing light to the more than 1.5 billion people around the world without access to electricity, the Royal Swedish Academy of Sciences noted. Indeed, several proposed solutions to energy poverty include the distribution of LED lights, particularly solar-powered ones.
Digital displays
Without blue LEDs, the world wouldn’t have back-lit smart phones, TV and computer LCD screens, blu-ray(蓝光) players, many forms of lighting, and countless other products.
In the electronics industry, LEDs provide back lighting for the liquid crystal displays (LCDs) in many smart phones, laptops, and televisions. The LEDs are more energy efficient and allow for very thin displays.
Blu-ray players use blue LED lasers(激光) to read data off a digital optical disc. When these systems switched from using an infrared(红外线) laser to a blue LED laser, it became possible to store five to 10 times as much data.
LEDs are now being explored for their potential to transmit(传送) data from the Internet across open space, similar to WiFi. Such a system could transmit a lot more data than WiFi alone. This high bandwidth is possible because LEDs can turn on and off millions of times per second.
The rise of LED lighting came at a time when people were just starting to be concerned about global warming. Because of LEDs’ energy efficiency, using them for the world’s lighting would have “an extreme impact” on society.
I___________ for Blue LED Lights to win the 2014 Nobel Prize in physics
●They_______ big changes in lighting.
II________ of LEDs
●Save and green
1. Compared with other forms of lighting, LEDs are much more efficient because of the different_________ they pass electric current
2. LED bulbs can be used 30 times longer than traditional bulbs.
●Lighting the world
1. Besides_ ___________ of LED bulbs they can also be used as street lights and car headlights.
2. Because of their high efficiency, LEDs, especially solar-powered ones, promising to light areas____________ electricity.
●Digital displays
1. Many smart phones, laptops and televisions use LEDs to back-light their LCD_________.
2. By using blue LED lasers, blu-ray players are likely to___________.
3. People are now exploring more_________ uses of LEDs such as transmitting data.
III Conclusion
LED lighting will_________ on environmental protection.
It is not easy to find true friends. Even if you’ve connected with someone, how do you really know he is a true friend? And often you will find that someone who you thought you could trust may have let you down. There are ways you can know if a friendship is true and how you can hold onto that friend.
Generally speaking, a true friend is someone who will be there for you no matter what happens. They will stand by you through bad and good times. They will accept you for who you are without trying to change you, and they will be there to help you grow in new ways.
A true friend will keep you secrets for you trust him. They will be honest and be someone you can depend on. They will listen and be someone you can talk things over with, even if they may not have advice to share with you.
However, friendship is a two-way street. To find true friends and keep them, you must in turn be the same as well. Be there for them in their hard times and share the good times with them. Be someone your friends can depend on as well and offer them the same thing they give to you. A friendship will fall apart fast if only one person is giving and putting all the effort. If you are the only one making an effort, be honest and it works.
Actually, there will be barriers in the road but that is the test of true friendship. If it can survive those barriers, it will be stronger and better than ever. Just as St Thomas Aquinas put it, “There is nothing on this earth more prized than friendship.”
| Find a True Friend |
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| The writer’s ( on friends |
●True friends( ●Those who you regarded as your friends may make you down. |
| Characteristics of true friendship |
●A true friend will( ●A true friend will keep your secrets and be a good( |
| ( friendship |
●( ●Be someone who your friends can( ●( |
| ( |
●True friendship can stand up to various( |
My older brother and I are busy (arrange) a trip to Africa. We will leave London on 15 July, and we’ll be flying to Morocco. We are going to travel on camels
the Sahara Desert. After the trip by camel, we’re going to travel down the River Nile. We’ll start at Lake Victoria. A little way down the river from Lake Victoria, the water
(actual) gets quite rough. So, we’ll go white-water rafting,
is quite dangerous, but very exciting! After white-water rafting, we’re going on a trip to see wild animals in Kenya.
we’ll be walking for almost two weeks, I’ll need to buy a large, strong, light backpack
advance to carry my
(supply) of food and water. It is so dangerous that our guides will have guns
(scare) the animals away if they come too near. I really want to see
elephant close up. After that, we’ll be moving on to Tanzania,
we’re going to climb Mount Kilimanjaro. The African part of our trip will take about four weeks and we will surely have a happy time.
Many of us invest valuable time,energy and money planning our vacations. We do this because we know for sure that going on vacations must be good for us. Research proves this feeling without a doubt. Vacations help us perform better at work, improve our sleep quality and cushion us against depression.
Yet, despite these benefits, many of us return home with a feeling that our last vacation was OK --- but not great. In order to change this, some mistakes should be avoided. A classic one for vacation planners is attempting to maximize value for money by planning trips that have too many components (组成部分).Perhaps you’re planning a trip to Europe, seven cities in 10 days,and you realize it will cost only a little more to add two more destinations to the list. It sounds fine in theory, but hopping from one place to the next hardly gives an opportunity to experience what psychologists call mindfulness(留意) --- time to take in our new surroundings, time to be present and absorb our travel experiences. Another mistake is that we worry too much about strategic issues such as how to find a good flight deal,how to get from A to B,or which destinations to add or subtract from our journey. These issues may seem important, but our psychological state of mind is far more important.
Actually, vacation happiness is based on the following top rules. First, choose your travel companions wisely, because nothing contributes more significantly to a trip than the right companions. Second,don’t spend your vacation time in a place where everything is too expensive so as to keep a positive mood. Third, shop wisely, for meaningful experiences provide more long-term happiness than physical possessions.
Ms. Mary was over eighty, but she still drove her old car like half her age. She loved driving very fast, and boasted of the fact she had never, in her thirty-five years of driving, been punished
a driving mistake.
Then one day, she nearly lost her record. A police car followed her, and the policemen in it saw her pass a red light without (stop).
When Ms. Mary came before the judge, he looked at her severely and said that she was too old to drive a car, and that the reason she had not stopped at red light was most probably that her eyes had become weak
old age, so that she had simply not seen it.
When the judge had finished he was saying, Ms. Mary opened the big handbag she was carrying and took out her sewing. Without saying a word, she
(choose) a needle with a very small eye, and threaded it at the first time.
When she had (success) done this, she took the thread out of the needle again and handed both the needle and thread to the judge, saying, “Now it is your turn. I suppose you can drive a car well, and you have no doubts
your eyesight.”
The judge took the needle and tried to thread it. After half a dozen times, he had still not succeeded. The case against Ms. Mary (dismiss解雇), and her record remained unbroken.
____________, they have been drilling for sixteen hours and they still have a long way to go.
People will do anything to see a free show---even if it is a bad one. When the news
______________ would be presented at our local cinema by the P. and U. Bird…
because balloons can be a great danger to aircraft. He said that someone ______________ the station and the pilot was ordered to _______
_______ the strange object.
Experiments have proved that children can be instructed in swimming ___________________.
Whether they will ever become future Olympic champions, _________________.
He looked pale and his clothes were in a frightful state. “What has happened?” she asked. “How did your clothes __________________?”
This is a moving spectacle, for crowds of people stand on the shore _________________ until they can be seen no more.