【推荐1】In daily life, there are some emergencies that you might have to deal with one day. Learn to handle the emergencies below for yourself, your family and friends.

Sudden heart attack

Having CPR training is the life-saving help for someone having a heart attack. Move the patient’s head back and look for breathing. If the patient doesn’t take a breath in less than 10 seconds, start CPR. Put your hands on the center of the chest. Push hard and fast—about twice per second. Push on the chest 30 times and then give mouth-to-mouth 2 times. Repeat cycles of the presses and mouth-to-mouth until the help arrives or the patient wakes up.

Choke

Stand behind the choking person. Put your arms around the waist and bend him or her slightly forward so that the object blocking the airway will move out of the mouth. Do this up to five times. You can also do back blows—firmly slap the person on the back with your hand while he or she is bent over. If the object still doesn’t come out, call 120.

Nosebleed

Ask the person to lean forward and pinch(捏) his nose for five to six minutes. Do not move his head backward, as the blood may run into his mouth or even his lungs.

Encourage the person not to speak,swallow, cough or spit because these may break blood clots(血块) that may have started to form in the nose. If the bleeding lasts more than 30 minutes, call 120 for medical help.

Burn

Burns should be treated by an adult—the injured area should be put under cool running water for 10 to 15 minutes to relieve the pain. Ice should never be used, as it can make the injury even worse. If a child has a serious burn, he or she should be taken to a doctor or the emergency room.

【推荐2】“I’ve been contacted by everyone from designers to companies that make clothes and shoes,” said Xiulin Ruan, a developer of the world’s whitest paint. They mainly had two questions: Where can I buy it, and can you make it thinner?”

The original world’s whitest paint could reflect (反射) 98.1% of sunlight, cooling outdoor surfaces more than 4.5°C below surrounding temperature. Cover your wall in that paint, and you could cool your home with much less air conditioning. But there’s a problem. “To achieve this level of cooling, we had to make it thick,” Ruan said. “That’s fine if you’re painting something strong. But in applications that have strict size and weight requirements, the paint needs to be thinner and lighter.”

That’s why Ruan’s team began experimenting with other materials. Their latest solution achieves nearly the same standard of solar (太阳的) reflectance (97.9%) with just a thin layer (层) of paint and it weighs 80% less.

“This light weight opens the doors to all kinds of applications.” said George Chiu, an expert in inkjet printing. “Now this paint has the chance to cool the surfaces of airplanes, cars or trains. An airplane sitting on a hot summer day won’t have to run its air conditioning as hard to cool the inside, saving large amounts of energy. Spacecraft also have to be as light as possible, and this paint can be a part of that.”

As to that other big question—where can I buy the paint—Ruan explains, “We are in discussions right now to put it on the market. There are still a few issues that need to be addressed, but progress is being made.”

Either way, these researchers look forward to what the paint could bring. “Using this paint will help cool surfaces and greatly reduce the need for air conditioning,” Ruan said. “This not only saves money, but it reduces energy usage, which in turn slows down global warming. It’s pretty amazing that paint can do all that.”

【推荐3】Few people realize it, but glaciers (冰川) are full of tiny air bubbles (气泡). They form as snow, accumulating over thousands of years, slowly packs into ice under its own weight — squishing the air that was trapped between snowflakes into tiny holes. Erin Pettit, a scientist, and her colleagues had suspected that bubbles could be important. To test this idea, they undertook a series of laboratory experiments.

They find that as the ice melted, the resulting fresh water rose, because it was less dense than the surrounding sea water. This created a rising current along the vertical face of the ice — a proof of what occurs at the front of a real tidewater glacier. When the glacial ice melted, the current that it produced was six times faster than what was seen with the bubble-free ice because the rising bubbles pulled the water up more quickly. The glacial ice melted 2.25 times more quickly than the bubble-free ice. “That’s a very powerful effect. If that’s the reality in nature, then it’s quite serious.”

The newly discovered bubble effect could explain some of that extra melting, says Mathieu Morlighem, a scientist. “It’s improving our understanding, but it’s not painting a darker picture of what’s happening today,” he says.

Pettit notes that in Alaska, many bays with tidewater glaciers have large populations of harbor seals. The animals shelter there while molting and raising babies. But in Glacier Bay, where the tidewater glaciers retreated (后退) many miles inland, the seal populations have declined. Pettit now suspects that the roaring rhythm of exploding bubbles provides a hiding place where seals can avoid detection by killer whale, which often find their victim by listening. The bubbles may mask the seals’ sounds — at least until the ice retreats out of hearing. This may turn out to be yet another way in which these tiny bubbles have surprisingly large-scale effects.

【推荐3】The now world-famous Lumière brothers, Auguste Lumière and Louis Lumière, were born in Besançon, eastern France, near the border with Switzerland. They grew up immersed in the dazzling potential of photography, pursuing the family passion for developing images.

Their father Charles-Antoine set up a small factory producing photographic plates, and the looming threat of bankruptcy (破产) in 1882 was just the sort of pressure needed to inspire the world’s greatest invention. It was these two boys who invented the machines necessary to automate their father’s plate production, known as the new photo plate “etiquettes bleue”, and saved the family business from sinking.

When their father eventually retired one decade later in 1892, the brothers decided to focus on creating moving pictures. The original cinématographe (电影机) was made by Léon Guillaume Bouly on 12 February 1892, but the brothers made their own more efficient version three years later on 13 February 1895.

One of their techniques for making film more efficient included film perforations (穿孔), which helped pass the film through the camera and projector with greater ease. The first-ever footage (片段) to be recorded using their new invention was recorded on 19 March 1895, a short film that showed workers leaving the Lumière factory in which the brothers worked.

The first public screening of their movies came a few months later in December 1895, and they used their invention of the cinématographe to show 10 movie-clips of about 50 seconds each.

Of course, there was Thomas Edison’s “peepshow” kinetoscope that existed before the French Lumière Brothers invented cinema. But the difference was, Edison’s “peepshow” did not allow simultaneous viewing, whereas the Lumière Brothers invented entertainment that could be enjoyed by the masses and all at once. And cinema has never been the same ever since.

【推荐1】There is no lack of excellent flying builders-such as bees-in nature. To build a nest, these insects team up to collect the needed materials and follow the specification of a complex design that ends up being many times their size. This building process takes months, even longer than their average lifespan, during which the insects must adjust as they go.

Inspired by these insect building teams, Mirko Kovac, a roboticist, developed a way to improve 3D printing for the construction industry. A typical 3D printer is limited by the range of its nozzle (喷嘴), and can only make objects smaller than itself. Besides, 3D construction robotics currently focuses mostly on ground-based robots. And large-scale systems that need to be connected to a power supply are limited in places where they can be laid out.

Dr Kovac’s team has removed these limitations by giving the printer nozzle wings. Dr Kovac describes a system of flying robots that is composed of two types of drones: BuilDrones and ScanDrones.

First, a builder flies over its area of operation and begins to release a jet of the building material. Once the builder robot has sprayed a layer of material, the scanner robot flies over and inspects the progress. The scanner then calculates the next layer that the builder should make, while also correcting any errors that might have been discovered in what has already been built. At this point, people can also step in the process when necessary.

The researchers tested the system’s capabilities by building both a large cylinder (圆柱体) (72 layers and 2 meters tall) made of a lightweight material, and a small one (28 layers, 18cm) made of a high-density mixture. The tasks were not simple. Making circles on top of other circles would not have worked, because the perfect alignment (required would have been impractical to achieve. As a result, Dr Kovac’s robots passed the test with flying colors-the cylinders were built to within 5mm of the width and height of the planned structures, which is of sufficient quality, as far as British building requirements are concerned.

Because the flying robots can, in theory, operate anywhere, they could fix things in dangerous or otherwise inaccessible places.

【推荐2】Concrete is one of the most widely used building materials today. It’s a composite material made from a mixture of broken stone or gravel, sand, Portland cement, and water, which can be spread or poured into molds and forms a mass resembling stone on hardening.

Around 3000 BC, the Egyptians used early concrete forms in their building.

One of concrete’s key ingredients is cement (水泥), which is thought to have been devised in Europe in 1300 BC. Later, cement would be combined with other materials to make a substance more similar to what we know as concrete today. The Romans, for example, are famed for their concrete; many structures built using it still stand today. But it could be older than that.

Middle eastern builders coated the outside of their clay fortresses with a thin, moist layer of burned limestone (石灰石), which chemically reacted with gasses in the air to form a hard, protective surface.

Around or before the third millennium BC, Nabataean traders or Bedouins built the first concrete-like structures in the southern Syria and northern Jordan regions. By 700 BC, the significance of lime was known, which led to the development of mortar supply kilns (窑厂) for the construction of rubble-wall houses, and concrete floors.

In 1824, Portland cement was invented by Joseph Aspdin of England. George Bartholomew laid down the first concrete-paved street in the US in 1893, which still exists.

By the end of the 19th century, steel-reinforced concrete was developed. In 1902, August Perret designed and built an apartment building in Paris using steel-reinforced concrete. This building had wide admiration and popularity for concrete and influenced the development of reinforced concrete.

In 1921, Eugene Freyssinet pioneered reinforced-concrete construction by building two airship hangars at Orly Airport in Paris.

【推荐3】Making Music Visible

On a recent afternoon in a brightly lit studio in Brooklyn, Tom and David were filming a music video. They were recording a different version of their favorite song, but the voices that filled the room were those of the two original singers, who made the song a hit. And yet the two men were also singing—with their hands.

Tom is a deaf actor and dancer; David is a hearing dancer and choreographer who is, thanks to seven deaf family members, a native speaker of sign language. Their version is part of a 10-song series of sign language covers of works.

Around the world, music connects together communities and promotes a sense of belonging. But as sign language music videos become an online phenomenon, the richness of sign language has gotten a broader stage.

“Music is many different things to different people.” Alice, a deaf actress told in an interview, using an interpreter. “I realize,” she added, “that when you do hear, not hearing may seem to separate us. But what is your relationship to music, to dance, to beauty? What do you see that we may learn from? These are conversations people need to get accustomed to having.”

A good sign language performance thinks highly of the combination of the elements of sign language—hand shape, movement and facial expression—with those of spoken language, allowing a skilled sign language speaker to engage in the kind of sound painting that composers use to enrich a text. “The hands have their own emotions,” Tom said. “They have their own mind.”

Deaf singers prepare for their performances by experiencing a song through any means available to them. Many people speak about their highly sensitivity to the vibrations of sound, which they experience through their body. As a dancer trained in ballet, Tom said he was particularly conscious of the vibrations of a piano as transmitted through a wooden floor.