Scientists from the University of East Anglia have identified four new man-made gases that are contributing to the damage to the ozone(臭氧) layer. Two of the gases are accumulating at a rate that is causing concern among researchers.

    Worries over the growing ozone hole have seen the production of chlorofluorocarbon (CFC) gases restricted since the mid 1980s. But the precise origin of these new, similar substances remains a mystery.

    Lying in the atmosphere, the ozone layer plays a critical role in blocking harmful UV rays, which cause cancers in humans and reproductive problems in animals.

    Scientists from the British Antarctic Survey were the first to discover a huge “hole” in the ozone over Antarctica in 1985. The evidence quickly pointed to CFC gases, which were invented in the 1920s, and were widely used in refrigeration. Extraordinarily, global action was rapidly agreed to deal with CFCs and the Montreal Protocol to limit these substances came into being in 1987. A total global ban on production came into force in 2010.

    Now, the newly discovered four new gases can destroy ozone and are getting into the atmosphere from as yet unidentified sources. Three of the gases are CFCs and one is a hydrochlorofluorocarbon (HCFC), which can also damage ozone.

    The research has shown that four gases were not around in the atmosphere at all until the 1960s, which suggests they are man-made. The scientists discovered the gases by analyzing polar snow pack. Air from this snow is a natural archive of what was in the atmosphere up to 100 years ago. There searchers also looked at modern air samples, collected at remote Cape Grim in Tasmania.

    They estimate that about 74,000 tonnes of these gases have been released into the atmosphere. Two of the gases are accumulating at significant rates. However, they don't know where the new gases are being released from and this should be investigated. Possible sources include chemicals for insecticide (杀虫剂)production and solvents (溶液) for cleaning electronic components. The three CFCs are being destroyed very slowly in :the atmosphere—so even if emissions (散发)were to stop immediately, they will still be around for many decades to come.

    Of the four species identified, CFC-113a seems the most worrying as there is a very small but growing emission source somewhere, maybe from agricultural insecticides. We should find it and take it out of production.

    I grew up in a house where the TV was seldom turned on and with one wall in my bedroom entirely lined with bookshelves，most of my childhood was spent on books I could get hold of. In fact，I grew up thinking of reading as natural as breathing and books unbelievably powerful in shaping perspectives (观点) by creating worlds we could step into，take part in and live in.

    With this unshakable belief，I，at fourteen，decided to become a writer. Here too，reading became useful. Every writer starts off knowing that he has something to say，but being unable to find the right ways to say it. He has to find his own voice by reading widely and discovering which parts of the writers he agrees or disagrees with，or agrees with so strongly that it reshapes his own world. He cannot write without loving to read，because only through reading other people's writing can one discover what works，what doesn't and， in the end，together with lots of practice，what voice he has.

    Now I am in college，and have come to realize how important it is to read fiction (文学作品)．As a law student，my reading is in fact limited to subject matter — the volume (量) of what I have to read for classes every week means there is little time to read anything else. Such reading made it all the clearer to me that I live in a very small part in this great place called life. Reading fiction reminds me that there is life beyond my own. It allows me to travel across the high seas and along the Silk Road，all from the comfort of my own armchair，to experience，though secondhand，exciting experiences that I wouldn't necessarily be able to have in my lifetime.

    A telescope, called Gaia, is being designed by astronomers in Europe, and it couldn't be more different from Pan-STARRS, which is another telescope being designed. While Pan-STARRS will be looking for asteroids (小行星) and comets headed for Earth, Gaia will be looking at our entire galaxy (银河系).

    Gaia is designed to draw a map of the Milky Way, our home galaxy. Just as a map of your town gives you a picture of where things are located, Gaia's map of the galaxy will tell astronomers where the stars are. Over five years, Gaia will observe (观察) about a billion stars and other objects in our galaxy. Each object will be observed about 70 times.

    Gaia will be sent into space connected to a rocket. It contains two telescopes, each focused at a different angle (角度). These two telescopes act like Gaia's “eyes”. The reason why humans can see things in 3D is that we have two eyes focused on the same object, at slightly different angles. By using two telescopes like eyes, Gaia can produce the first 3D map of the positions of the stars it views.

    Gaia, which is to be sent into space, will be a powerful telescope. If you were to use it on Earth, for example, you could stand 600 miles away from your best friends and still get a clear picture of their hair.

    Gaia is one of more than a dozen telescopes being designed by scientists right now. The next generation of telescopes will reveal new parts of our universe that will seem surprising. The universe, with all its planets, stars and other strange objects, is a puzzle with pieces that we can see by using powerful telescopes.

    There's a new frontier in 3D printing that's beginning to come into focus: food. Recent development has made possible machines that print, cook, and serve foods on a mass scale. And the industry isn't stopping there.

    Food production

    With a 3D printer, a cook can print complicated chocolate sculptures and beautiful pieces for decoration on a wedding cake. Not everybody can do that — it takes years of experience, but a printer makes it easy. A restaurant in Spain uses a Foodini to "re-create forms and pieces" of food that are "exactly the same," freeing cooks to complete other tasks. In another restaurant, all of the dishes and desserts it serves are 3D-printed, rather than farm to table.

    Sustainability(可持续性)

    The global population is expected to grow to 9.6 billion by 2050, and some analysts estimate that food production will need to be raised by 50 percent to maintain current levels. Sustainability is becoming a necessity. 3D food printing could probably contribute to the solution. Some experts believe printers could use hydrocolloids (水解胶体) from plentiful renewables like algae(藻类) and grass to replace the familiar ingredients(烹饪原料). 3D printing can reduce fuel use and emissions. Grocery stores of the future might stock "food" that lasts years on end, freeing up shelf space and reducing transportation and storage requirements.

    Nutrition

    Future 3D food printers could make processed food healthier. Hod Lipson, a professor at Columbia University, said, "Food printing could allow consumers to print food with customized nutritional content, like vitamins. So instead of eating a piece of yesterday's bread from the supermarket, you'd eat something baked just for you on demand."

    Challenges

    Despite recent advancements in 3D food printing, the industry has many challenges to overcome. Currently, most ingredients must be changed to a paste(糊状物) before a printer can use them, and the printing process is quite time-consuming, because ingredients interact with each other in very complex ways. On top of that, most of the 3D food printers now are restricted to dry ingredients, because meat and milk products may easily go bad. Some experts are skeptical about 3D food printers, believing they are better suited for fast food restaurants than homes and high-end restaurants.

    Humans and elephants don't always get along. In Africa and Asia, elephants damage equipment, farmers' crops, and natural habitat for other species. If an elephant becomes a problem, humans may kill it. So local people and animal protectionists are trying to find better ways to keep elephants away from sensitive places. Now, researchers think they have a good tool to prevent elephants: honeybee pheromones (信息素).

    “Elephants dislike being stung(叮咬) in the trunk, because it's an extremely sensitive organ. Imagine being stung in your nose by a bee, and multiply that a few thousand times.” said Mark Wright, a professor at the University of Hawaii.

    Kenyan farmers have long known that if they hang live beehives (蜂箱) around their farms, they will drive elephants away. The problem is how to manage hundreds of thousands of hives, if you have a huge area to protect. And then the idea came up to look at the alarm pheromones, which are chemicals that the bees release to launch an attack on something that's damaging the hive.

    So the researchers tested out an artificial mixture of chemicals that imitates (模仿) honey bees' alarm pheromones. The researchers hung white socks treated with the artificial mixture as well as untreated control socks around an elephant watering hole, and then observed the animals' behavior. “Elephants are really curious creatures. They'll walk along and see something like a sock hanging on a branch. If it's not treated with the alarm pheromones, they'll pick it up, throw it around, and try to taste it, things like that. And in the case of the treated ones, they would show immediate signs of unease or uncertainty, and they'd eventually back off from them.”

    In order to avoid the elephants more effectively, the researchers plan to make the pheromone mixture purer. That way, elephants will stay far away from wherever they should not be going-and both elephants and humans can coexist a bit more peacefully.

The following 4 famous paintings — from Jan van Eyck's portrait to Pablo Picasso's masterpiece — have stood the test of time.

The Amolfini Portrait

Jan van Eyck's Amolfini Portrait, an oil painting on wood produced in 1434, in which a man and a woman hold hands with a window behind him and a bed behind her, is undoubtedly one of the masterpieces in the National Gallery, London. This painting is as visually interesting as it is famed. It is also an informative document on fifteenth-century society, through van Eyck's heavy use of symbolism — while husbands went out to engage in business, wives concerned themselves with domestic duties.

The Starry Night

Vincent van Gogh painted The Starry Night, oil on canvas (帆布), a moderately abstract landscape painting of an expressive night sky over a small hillside village, during his 12-month stay at the mental hospital near Saint–Remy-de-Provence, France between 1889 and 1890. When the Museum of Modem Art in New York City purchased the painting from a private collector in 1941, it was not well known, but it has since become one of van Gogh's most famous works.

The Harvesters

The Harvesters is an oil painting on wood completed by Pieter Bruegel the Elder in 1565. It depicts the harvest time which most commonly occurred within the months of August and September. Nicolaes Jonghelinck, a merchant banker and art collector from Antwerp, commissioned this painting. The painting has been at the Metropolitan Museum of Art in New York City since 1919.

Guernica

Guernica, a large black-and-white oil painting, was painted by the Cubist Spanish painter, Pablo Picasso in 1937. The title 'Guernica' refers to the city that was bombed by Nazi planes during the Spanish Civil War. The painting depicts the horrors of war and as a result, has come to be an anti-war symbol and a reminder of the tragedies of war. Today, the painting is housed at the Museo Nacional Centro de Arte Reina Sofia in Madrid.