What will power your house in the future？Nuclear, wind, or solar power？According toscientists at the Massachusetts Institute of Technology(MIT)in the US, it might beleaves—but artificial(人造的)ones.

    Natural leaves are able to change sunlight and water intoenergy. It is known as photosynthesis(光合作用). Nowresearchers have found a way to imitate this seemingly simple process.

    The artificial leaf developed by Daniel Nocera and hiscolleagues at MIT can be seen as a special silicon chip with catalysts(催化剂). Similar tonatural leaves, it can splitwater into hydrogen and oxygen when put into a bucket of water. The hydrogenand oxygen gases are then stored in a fuel cell, which usesthose two materials to produce electricity, located eitheron top of a house or beside the house.

Though the leaf is only about the shape of a poker card, scientistsclaimed that it is promising to be an inexpensive source of electricity indeveloping countries.“ One can imagine villages in India and Africa not longfrom now purchasing an affordable basic power system based on this technology, ”said Noceraat a conference of the American Chemical Society.

    The artificial leaf is not a new idea. The first artificial leafwas invented in 1997 but was too expensive and unstable for practical use. Thenew leaf, by contrast, is made ofcheap materials, easy to useand highly stable. In laboratory studies, Nocera showedthat an artificial leaf prototype(原型)could operatecontinuously for at least 45 hours without a drop in activity.

    The wonderful improvements come from Nocera's recent discoveryof several powerful, new andinexpensive catalysts. These catalysts make the energy transformation insidethe leaf more efficient with water and sunlight. Right now, the new leafis about 10 times more efficient at carrying out photosynthesis than a naturalone. Besides, the device canrun in whatever water is available；that is, it doesn'tneed pure water. This is important for some countries that don't have access topure water.

    With the goal to “make each home its own power station” and“give energy to the poor”, scientistsbelieve that the new technology could be widely used in developing countries, especially inIndia and rural China.

Choose Your One-Day-Tours!

    Tour A—Bath &Stonehenge including entrance fees to the ancient Roman bathrooms and Stonehenge —￡37 until 26 March and ￡39 thereafter.

    Visit the city with over 2,000 years of history and Bath Abbey, the Royal Crescent and the Costume Museum, Stonehenge is one of the world's most famous prehistoric monuments dating back over 5,000 years.

    Tour B—Oxford & Stratford including entrance fees to the University St Mary's Church Tower and Anne Hathaway's —￡32 until 12 March and ￡36 thereafter.

    Oxford: Includes a guided tour of England's oldest university city and colleges. Look over the “city of dreaming spires(尖顶）”from St Mary's Church Tower. Stratford: Includes a guided tour exploring much of the Shakespeare wonder.

    Tour C—Windsor Castle &Hampton Court including entrance fees to Hampton Court Palace —￡34 until 11 March and ￡37 thereafter.

    Includes a guided tour of Windsor and Hampton Court, Henry VIII's favorite palace. Free time to visit Windsor Castle(entrance fees not included).With 500 years of history, Hampton Court was once the home of four Kings and one Queen. Now this former royal palace is open to the public as a major tourist attraction. Visit the palace and its various historic gardens, which include the famous maze(迷宫)where it is easy to get lost!

    Tour D—Cambridge including entrance fees to the Tower of Saint Mary the Great—￡33 until 18 March and ￡37 thereafter.

    Includes a guided tour of Cambridge, the famous university town, and the gardens of the 18th century.

    People usually visit cafes to ease themselves of their tiredness and keep themselves from falling asleep, but Mr. Healing, a popular cafe chain in South Korea actually does the opposite. Customers can come in, order a drink, lie down a comfortable massage chair, and take a nap.

    Many Koreans suffer from a lack of sleep as a result of overworking, so any opportunity to relax and even take a nap is greatly appreciated. Mr. Healing is the perfect place to go when you're on a short work or school break and you need to catch up on sleep. The cafe offers massage periods in various modes, depending on how much time you have and how you choose to spend it.

    The 20-minute session is priced at $ 3.5, the 30-minute massage costs $ 7, and the 50-minute session is $ 9, all of which also include a drink. Once you make your choice, you are taken to the “healing center”. You are asked to take off your shoes as well as any jewelry that might damage the chairs, after which you can choose a massage mode, from “stretch” or “sleep”. You can start with stretch for a few minutes, and then switch to sleep if you want to take a short nap. After it comes to an end, you are taken back to the cafe area to enjoy a coffee or one of the many other refreshing drinks on the menu.

    Mr. Healing cafes are so popular in Korea that customers are advised to make reservations in advance to be sure that a massage chair is available. “I have to sit on a chair and stare at a computer monitor all day due to my job, the healing room was truly effective to relieve tiredness and stress from weekdays,” said Park Hye-sun, a 24-year-old officer.

    Some have described Mr. Healing and other similar relaxation cafes in South Korea as simple fashions, but others see them as a sustainable business model, because they offer a service that Koreans really need.

    Dogs were living as companions to the early settlers of North America over 10,000 years ago. The oldest domestic dogs in the Americas were thought to be around 9500 years old. Angela Perri of Durham University, UK, and her colleagues have carried out fresh radiocarbon dating on the two dog skeletons that gave this date, discovered in the prehistoric Koster site in Illinois, and found they were even older: around 10,100 years old.

    A third dog from another Illinois site called Stilwell II was older still, at 10,190 years old. That makes it the oldest known domesticated dog in the Americas. The team concluded that all three dogs were domesticated as they skeletons were complete and unskinned, and so hadn't been butchered for food. They had also been carefully buried, evidence they were valued by their owners. The Stilwell II dog, which probably resembled a small English settler, was under what seemed to be the floor of a living area. It is unclear why it took so long for tame dogs to arrive in the Americas, given that they were domesticated at least 14,000 years ago in Eurasia. By this time, people were already moving into North America from Siberia; there is evidence some reached Chile 18,500 years ago. Geneticists have found signs of at least three waves of migration over the following millennia. There is no evidence that domestic dogs accompanied them. “We don't know if dogs were part of the first waves of immigration to the Americas" says Luc Janssens of Ghent University in Belgium. "It could be so, but no archaeological bones have yet been found." It is "overwhelmingly probable" that some of the early settlers did bring dogs to the Americas, but they may not have had "the time or the spiritual compulsion to bury them", says Pat Shipman of Pennsylvania State University.

    Three men traveling on a train began a conversation about the world's greatest wonders.

    "In my opinion, "the first man said, "the Egyptian pyramids are the world's greatest wonder. Although they were built thousands of years ago, they are still standing. And remember: the people who built them had only simple tools. They did not have the kind of machinery that builders and engineers have today."

    "I agree that the pyramids in Egypt are wonderful," the second man said, "but I do not think they are the greatest wonder. I believe computers are more wonderful than the pyramids. They have taken people to the moon and brought them back safely. In seconds, they carry out mathematical calculations that would take a person a hundred years to do."

    He turned to the third man and asked, "What do you think is the greatest wonder in the world?"

    The third man thought for a long time, and then he said, "Well, I agree that the pyramids are wonderful, and I agree that computers are wonderful, too. However, in my opinion, the most wonderful thing in the world is this thermos."

    And he took a thermos out of his bag and held it up.

    The other two men were very surprised. "A thermos?" they exclaimed. "But that's a simple thing."

    "Oh, no, it's not," the third man said. "In the winter you put in a hot drink and it stays hot. In the summer you put in a cold drink and it stays cold. How does the thermos know whether it's winter or summer?"

    Charles Darwin lived an unusually quiet life. In 1842, Darwin and his wife Emma moved from London to Kent in southern England to have as little disturbance (烦扰) as possible. They already had two children then, and would go on to have eight more in the country.

    Darwin had very regular (有规律的) habits. He rose early and went for a walk. After breakfast he worked in his study until 9：30 am, his most productive time of the day, and then read his letters lying on the sofa before returning to work.

    At midday he would go for another walk with his dog, stopping at his greenhouse to inspect (查看) his experiments. Then he would go for another walk around an area of woodland. While walking on his "thinking path", Darwin would consider his unsolved scientific problems.

    After lunch he read the newspaper and wrote letters. His network of friends provided information from all corners of the world.

    The Darwins were not very strict parents and the children were always seen running wild. Their father worked patiently to a background of playful shouts and little footsteps walking past his study door.

After dinner Darwin played backgammon (a game for two people to play) with his wife. He once wrote, "Now the result with my wife in backgammon stands like this: she... has won only 2,490 games, while I have won, hurrah (a cheer of joy or victory), hurrah, 2,795 games!"

    Although he had poor health, Darwin continued to publish (出版)a lot of creative works until his final book in 1881. He died the following year, aged 73.

    Rather than a quiet space in the local churchyard, which he called "the sweetest place on Earth", Darwin was given a state funeral (国葬) in London's Westminster Abbey.