Japanese researchers say they have developed a new type of glass that can heal itself from cracks and breaks. Glass made from a low weight polymer (聚合物) called “polyether-thioureas” can heal breaks when pressed together by hand without the need for high heat to melt the material.

    The research, published in Science, by researchers led by Professor Takuzo Aida from the University of Tokyo, promises healable glass that could potentially be used in phone screens and other fragile (易碎的) devices, which they say are an important challenge for sustainable (可持续的) societies.

    While self-healing rubber and plastics have already been developed, the researchers said that the new material was the first hard substance of its kind that can be healed at room temperature. The new polymer glass is “highly robust mechanically yet can readily be repaired by compression (压紧) at broken surfaces”.

The characteristics of the polyether-thioureas glass were discovered by accident by a graduate school student named Yu Yanagisawa, who was preparing the material as a glue. Yanagisawa found that when the surface of the polymer was cut, the edges would adhere to each other, healing to form a strong sheet after being manually compressed for 30 seconds at 21℃. Further experiments found that the healed material regained its original strength after a couple of hours.

    Yanagisawa told NHK that he didn't believe the results at first and repeated his experiments several times to confirm the finding. He said, “I hope the repairable glass becomes a new environment-friendly material that avoids the need to be thrown away if broken.”

    This is not the first time a polymer has been suggested as a healable screen for devices such as smartphones. Researchers at the University of California suggested the use of polymer that could stretch to 50 times its original size and heal breaks within 24 hours.

    Smartphone manufacturers have already used self-healing materials in devices. LG's G Flex 2 shipped in 2016 with a coating on its back was capable of healing minor scratches over time, although failed to completely repair heavier damage.

    According to the research conducted by repair firm iMend, over 21% of UK smartphone users were living with a broken screen, with smashed displays being one of the biggest issues alongside poor battery life.

    Two new studies suggest that modem running shoes could increase the risk of injuries to runners.

    One study involved sixty-eight healthy young women and men who ran at least twenty-four kilometers a week. The runners were observed on a treadmill machine (跑步机). Sometimes they wore running shoes. Other times they ran barefoot.

    Researchers from the JKM Technologies Company in Virginia, the University of Virginia and the University of Colorado did the study.

They found that running shoes create more stress that could damage knees, hips and ankle joints than running barefoot. They observed that the effect was even greater than the effect reported earlier for walking in high heels.

    The study appeared in the official scientific journal of the American Academy of Physical Medicine.

    The other study appeared in the journal Nature. It compared runners in the United States and Kenya. The researchers were from Harvard University in Massachusetts, Moi University in Kenya and the University of Glasgow in Scotland.

    They divided the runners into three groups. One group had always run shoeless. Another group had always run with shoes. And the third group had changed to shoeless running.

    Runners who wear shoes usually come down heel first. That puts great force on the back of the foot. But the study found that barefoot runners generally land on the front or middle of their foot. That way they ease into their landing and avoid striking their heel.

    Harvard's Daniel Lieberman led the study. He says the way most running shoes are designed may explain why those who wear them land on their heels. The heel of the shoe is bigger and heavier than other parts of the shoe, so it would seem more likely to come down first. Also, the heel generally has thick material under it to soften landings.

    But the researchers do not suggest that runners immediately start running barefoot. They say it takes some training. And there can be risks, like running when your feet are too cold to feel if you get injured.

    The study was partly supported by Vibram, which makes a kind of footwear that it says is like running barefoot. The findings have gotten a lot of attention. But the researchers say there are many problems in the way the press has reported in their paper. So they have tried to explain their findings on a Harvard Website.

    Do you worry about entering senior high school? Everything, from study to environment, has changed. Can you adapt yourself to it?

    You're not alone. Remember that everybody else in your year is in the same boat. You may not notice it, but they're just as nervous as you are.

    Moving to senior high school is a chance, not a problem. Things are different, and all you need to do is to be polite and learn the new rules.

    The teachers will help. If you don't know what to do or are worried about something, then ask for help. Teachers are probably the best people to turn to, because they have experience in helping new students. Pay attention to what your teachers say.

    Everything changes. There are lots of differences between junior high school and senior high school. You will have your lessons with different teachers in different rooms. You will have homework for different subjects on different days, so make sure you get organized. Make sure you know which rooms your classes are in and which days you have your different subjects on.

Other points:

    If you've got an older brother or sister at the school, then ask them for advice.

    Be yourself! It sounds simple, but things will become better if you just act naturally.

    Having early nights makes a difference. You'll also find it easier to get up in the morning!

    We are lucky to live in a world that is full of incredible technology. Our living rooms are packed with computers, LCD TVs, video game systems, and Blue-ray players that help us enjoy the latest entertainment. Although these items bring us joy and convenience, they also create a lot of junk. Each device needs its own plug and adaptor to keep its batteries recharged, and over time these wires get tangled (缠绕在一起的). Thankfully, something has come along to help rid our homes of this mess while still supplying these devices with the power they need. It's called wireless charging and this trend is just starting.

    Wireless charging has a lot of potential for smartphones and other electronic devices. Electronic devices can absorb the electricity once they're placed on a special charging mat. There are several advantages that wireless charging offers over traditional methods. For starters, cords (电线) have a tendency to wear out with use. Wireless charging users never have to worry about buying replacement cords. Wireless charging is also far more convenient for medical implants, as patients won't need to recharge their devices through the skin using cords. In turn, this cuts down on the risks of infection. Wireless charging can also bring safety benefits, as wired charging devices that come in contact with water can increase the chances of getting an electric shock. Wireless charging gets rid of that danger completely.

    Still, there are a few drawbacks to wireless charging. The first is speed. It takes a bit longer to charge devices wirelessly than it does if the device is plugged in. The process also requires more heat, so devices tend to get a bit hotter, which could create other safety issues. Also, since devices must be left on a special pad while charging, it is harder to operate them while they are powering up. This limitation may be gotten rid of in the future, as researchers are developing transmitters (发射器) that can charge several different devices in a room without the need to connect to a charging pad. Although wireless-charging technology may be far from perfect, it seems like a step in the right direction as we move towards a less-tangled future.

    Tiny as they are, bats have the ability to “see” in the dark by using a special skill called echolocation(回声定位法). They make noises and wait for sound waves, or an echo, to bounce(反弹) back off objects. They can tell the distance of various objects by how quickly the sound waves bounce back off them. If no sound bounces back, they can then fly forward.

    This special ability has been simulated in the human world for a long time, such as in submarines and planes, whose sonar(声呐) systems are somewhat similar to echolocation. But apart from helping vehicles “see” where they are, what if blind people could use echolocation for themselves? It turns out, some already are.

    American Daniel Kish, who is blind, is known as “Batman”. This isn't because he walks around in a cape and a mask, but because he has a bat-like ability to locate where he is through sharp clicks he makes by moving his tongue against the roof of his mouth. Kish is so skilled at echolocating that he can ride a bike and hike on his own.

    Recently, research carried out at the University of Durham in England shed some light on the power of human echolocation.

    Kish worked with a group of scientists who studied the way blind people listen to the echoes that they produce from clicks.

    The team, which conducted experiments with other volunteers, found that people were capable of hearing even very faint echoes, ones far fainter than had been previously thought.

    Speaking to The Independent, Lore Thaler, lead scientist of the group, said, “We found that in some conditions, they were really faint – about 95 percent softer than the actual clicks, but the echolocators were still able to sense this.”

    Andrew Kolarik of the University of Cambridge is another expert in echolocation. Reacting to the Durham study, he told BBC News that echolocation “can be very useful at providing information at face or chest height” and could help people “avoid objects like low hanging branches that might not get detected by the cane or a guide dog”.

    Although Kish's skill is remarkable, there's hope for other blind people who want to use echolocation. According to BBC News, echolocation is a skill blind people can acquire and develop, just like learning a language. As Kolarik said: “Teaching echolocation skills could provide blind people with the means of exploring new places.”

    A while back I caught a news report on something called -couch surfing‖ and the network of trusting souls who make this phenomenon possible. They offer to put up travelers free of charge and help them on their ways. At first, it sounded unbelievable. I mean, inviting strangers into one's home for one or two nights? Give me a break.

    However, I was intrigued. I decided to investigate. The only way to truly learn about this phenomenon was to dive in. So I planned a trip to Finland, a country I've always wanted to explore. I would couch surf at every stop there.

    If ever any anxiety existed when stepping into the unknown, it disappeared when my first host met me at the train station. Ari looked like my idea of a typical Finn: tall and blue-eyed. Finns were also supposed to be famously reserved (寡言少语的). Ari was anything but. He was a live wire, giving me an enthusiastic welcome and hiking with me to his apartment, where he showed me the sleeper sofa, served me tea, and engaged me in warm conversations. He also handed me a key to come and go as I pleased.

    If this was what couch surfing was all about－trust and friendship－then I had gotten off to a good start. As I boarded my next train to continue my journey, I began to think about this couch-surfing idea. What urged these people to open their homes to strangers? I concluded that there was a desire to lend a hand to like-minded folks who might enrich their own lives.

    Seven cities in 14 days. Seven hosts. Seven new friends. If couch surfing taught me anything, it's this: Most people are good and generous. Where will couch surfing take me next? Who knows? But I can't wait to find out.