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.

When it comes to cultural heritage protection, the Grand Canalof China is probably the world's greatest project of its kind. The big inland waterway system in thenorth-eastern and central eastern plains passes through eight of the country'spresent-day provinces.

The Canal runs from Beijing in the north to Zhejiang Province inthe south. Constructed in sections from the 5th century BC onwards, it wasdesigned as a means of communication in the 7th century AD. The Canal is the world's greatest civilengineering project before the Industrial Revolution.

The Grand Canal reached a peak in the 13th century, providing aninland navigation(航行) networkconsisting of more than 2,000 kilometers of artificial waterways, linking fiveof the most important river basins in China, including the Yellow River and theYangtze. It entered a bid as a UNESCO(联合国教科文组织) culturalheritage site in 2008.

The Grand Canal cultural square is located in Beijing's Tongzhoudistrict. Ever since the Yuan dynasty 800 years ago, the Tongzhou section ofthe Grand Canal has been the life blood of Beijing. Grain and buildingmaterials were all transported to meet the endless demands of the big cities.Even today, the Grand Canal plays a major role in the lives of its citizens.

"I grew up near the Grand Canal. In the past the waterwaywas a lot narrower, but now it's nice and wide and bridges are built over it. Ithink if the bid for world heritage status succeeds, it will greatly makeTongzhou more famous in the world, especially with Tongzhou aiming to be asub-center of the capital Beijing," a citizen said.

The result of the bid is set to be released next week, and nodoubt it will certainly make it into the history books if the Canal is listedas a world heritage site.

    Located in the inner London Borough of Southwark, this hugely improved non-selective Secondary Academy School is looking to recruit (招募) and appoint a talented Science Teacher in April 2016 or sooner.

POSITION：Science Teacher |KS3 —5| All Science specialists are welcomed

DEPARTMENT：Popular & Ambitious Science Department

LOCATION：Borough of Southwark —Zone 2 —Inner London

PERSON：Qualified Science Teacher required —experience in UK

START DATE：April 2016 or sooner —full time & permanent contract on offer

SALARY：Inner London Pay Scale —£29,270 ～ £37,862 a year

PERSON REQUIREMENT：

    All applicants will need to be suitably skilled, trained and qualified to be considered for this Science Teacher position. Applicants should feel confident across Key Stage 3, 4 and 5, in addition to having a real desire to make a difference and provide pupils under their care with a first class education.

    SCHOOL & TRAVEL INFORMATION：

    This is a typically diverse inner city school, suitable for a broad range of pupils aged 11 to 18 years old. The school has made huge steps and progressed from a satisfactory to a good school. Results are constantly improving, thanks to the staff in place, who are responsible for creating and delivering a broad curriculum. The school site is a short walk away from the nearest underground and rail stations, positioned within inner London, Zone 2. Those living in South and Central London are perfectly positioned for this position.

    If you are a hardworking Science Teacher, hoping to become part of an improving Inner London Secondary, get in touch today. Please apply and submit your up-to-date CV using the form. One of the Clarus Education Team will be in touch within 48 hours if shortlisted(入围).

    Custom tattooed fish (纹身鱼) may be big sellers at markets, but an animal expert say it is a cruel and potentially lethal practice.

    In Laitai Flower and Fish Market near the Lufthansa Center in Beijing, four of over 20 fish stores sell marine ornamental fish that are tattooed using laser (激光) guns with beautiful images in order to make them more attractive to customers. Many people just love these kinds of fish, which gives them a unique visual impression. The price of these fish ranges from 50-100 yuan. Some customers are willing to pay an additional 100 yuan to have Chinese characters tattooed on to the fish. The most popular characters are “zhaocai” (attracting fortune) and “fu” (blessing). The color of tattooed fish won't fade away, and the fish can be cared for as regular fishes:

    But Ye Zhenjiang, a professor from the Ocean University of China, said “the practice would damage a fish's mackerel scale, which is its protective layer. Although I haven't done any research on the impact of the laser on mackerel scale, it is obvious that the mackerel scale may be infected or even destroyed under the exposure of laser,” Ye said. “It's like tattooing a human being's body, and it breaks the physiological balance of the fish and damages: the skin's protective surface, It may even cause death among fishes which have thin mackerel scale.”

    A specialist in aquatic(永生的) animal study surnamed Xu, from the Beijing Fisheries Research Institute, said, “We have no specific regulations to prevent fish from being tattooed. An official surnamed Bai from the Fishery Surveillance and Administration Bureau(FSAB), said there is no study showing that the laser threatened a fish's health. He said a regulation on small animal protection, to be passed in the near future, doesn't include regular aquatic animals. He said the institution is only responsible for aquatic animals that are on the verge of extinction. He said tattooed fish are mainly from south China's Guangdong province because Beijing does not have the laser technology to tattoo a fish.

    “It's too brutal to tattoo pictures or characters on fishes, even if it makes them more beautiful,” many tropical fish buyers told METRO yesterday. “We would never buy fish like that and we prefer them with natural beauty.”

    The old man walked with a cane（拐杖）slowly into the restaurant. His poor jacket.

    patched（打补丁）trousers and worn-out shoes made him stand out from the usual Saturday morning breakfast crowd. Unforgettable were his pale blue eyes that sparkled like diamonds，large rosy cheeks，and thin lips held in a steady smile.

    He walked towards a table by the window. A young waitress watched him and ran over to him， saying，“Here, Sir. Let me give you a hand with that chair”

    Without a word，he smiled and nodded a thank you. She pulled the chair away from the table. Steadying him with one arm， she helped him move in front of the chair， and get comfortably seated. Then she pushed the table up close to him，and learned his cane against the table where he could reach it.

    In a soft，clear voice he said, “Thank you, Miss”

    “You are welcome, Sir.” she replied，“My name is Mary. I'll be back in a moment. If you need anything, just wave at me.”

    After he had finished a hearty meal of pancakes，bacon，and hot lemon tea，Mary brought him the change, helping him up from his chair and out from behind the table. She handed him his cane， and walked with him to the front door. Holding the door open for him, she said, “Come back and see us, Sir.”

    He nodded a thank you and said softly with a smile, “You are very kind！”

    When Mary went to clean his table，she was shocked. Under his plate she found a business card and a note written on the napkin, under which was a 100$ bill.

    The note on the napkin read，“Dear Mary，I respect you very much， and you respect yourself，too. It shows by the way you treat others. You have found the secret of happiness. Your kind gestures will shine through those who meet you. ”

    The man she had served was the owner of the restaurant. This was the first time that she，or any of his employees, had seen him in person.

    You're probably used to the regular upgrades in our cell-phone networks. There was 2G, which came along in 199l, replaced with 3G in 2001, followed by 4G in 2009. Now we're hearing about the coming of 5G.

    But 5G is a much bigger leap than before. 5G, of course, is much faster than 4G in the real world and a 5G phone in a 5G city will enjoy Internet speeds between 9 and 20 times as fast. The arrival of 5G also means enormous leaps forward in capacity－so much that every cell-phone plan will offer cheap, truly unlimited Internet access. "The consequences of that are huge," says Sherif Hanna, Qualcomm's director of 5G marketing. For example, apps will no longer degrade (降低) your video quality or postpone downloading when you're out of Wi-Fi range. In fact, you'll probably prefer to do your downloads when you're on cellular (使用流量) because 5G will be much faster than whatever service you've got at home or work.

    "However, not everyone is excited by the 5G development. The new standard gets its speed partly by using existing transmission(传输) frequencies more efficiently and partly by using the millimeter wave range. That's a big, juicy line of radio frequencies that are currently underused because millimeter wave is really hard to use," Hanna says.

    These frequencies are much higher than anything we've used for the cellular, which means they can offer unbelievable speed－but at the cost of range. Millimeter wave cellular towers have to be about 500 feet apart. Cell carriers not only will have to upgrade all their cell transceivers (called small cells) but will install(安装) a lot more of them as well.

    That's why the millimeter wave flavor of 5G, the superfast coverage, will be available only in densely populated cities such as New York and San Francisco. In suburban and rural areas, 5G will bring a speedup of "only" nine times faster.