【推荐2】Thomas Wallin at Cornell University in New York and his colleagues have created soft robotic grippers(机械爪）that are capable of sweating to cool down.

The grippers are capable of a cooling capacity of 107 watts per kilogram,making them more efficient sweaters than mammals.By comparison,humans and horses have a maximum cooling capacity around 35 watts per kilogram.

Each gripper consists of three finger-like parts that bend simultaneously(同步地）to grasp small objects.The 3D-printed grippers are made from hydrogels -materials which can store large amounts of water.Each finger is made from an underlayer with an internal channel to let fluid flow and is capped with a surface layer containing micropores(微孔）。

At cold temperatures,the pores close.At temperatures higher than 30C,the surface layer expands,enabling pressurised fluid from the underlayer to sweat out.The material responds simultaneously to temperature changes without the need for external sensors.

＂Sweating takes advantage of evaporative water loss to rapidly dissipate(使消散）heat,”said Wallin in a press briefing yesterday.Unlike convection or radiation,sweating lowers the temperature of a body below that of its environment,he said.

＂When the local temperature rose above the transition,the pores would simply open on their own,"said Wallin.

When blown by wind from a fan,the sweating robots cooled at a rate of 39.1C per minute, about six times faster than similar devices that are unable to sweat.The technique could be used to help robots operate for long periods of time without overheating,said team-member Robert Shepherd,also at Cornwell.

However,there is currently no means for the robot to replenish(补充）its fluid stores after sweating.This means"the robots that operate via the autonomous sweating that we've created would have to also be able to drink",said Shepherd.

【推荐3】Having a light electric bike that can be folded(折叠) in to fit your backpack would be very practical, don’t you agree? Well, it seems Smacircle is the answer.

Inventors have created an electric bike called Smacircle which is not only as light as two newborn babies but folds up and fits in a backpack. The ebike can reach speeds of 20km/h and is controlled with a smartphone app.The ebike folds up into a backpack in less than ten seconds, by which time it’s no taller than 49cm. It weighs a little over 7kg and can be suitable for riders of different sizes. Powered by a 240W motor and built-in battery, this ebike allows you to ride up to 20km distance.

The first models have been made and tested, and its makers are seeking further investment with an aim to bring it to the mainstream market. Chinese designers believe it might change the way people commute (通勤) to work. They can avoid crowded public transport, simply go through heavy traffic, perfect to commute in the city when their destination is too far to walk yet too close to drive.

CEO Gavin Yang, from Shenzhen in China, said, Smacircle is a special creative design invented to fill in the gap in short commute personal transportation. Their team has spent countless hours on research and development, and are determined to bring the people the best possible solution for short commutes, he said.

As it has not yet hit the market, there is no price available. We have spent almost two years developing this Smacircle ebike and now we have made the concept a reality, said Mr Yang.

【推荐1】Scientists often compare coral reefs(珊瑚礁) to underwater rainforests, yet unlike the leafy plant base of a forest, corals are animals. The soft creatures are naturally half-transparent and get their brilliant color from algae(藻类) living inside them. When corals experience stress from hot temperatures or pollution, they halt the interdependent relationship with algae, typically pushing them out and turning white. Corals are still alive when they are white, but they're at risk and many eventually die, turning dark brown.

Scientists around the world are looking for means to protect and maybe increase corals. One common option is to create more protected areas — essentially national parks in the ocean. Beyond nature preserves, some conservationists are looking to more hands-on methods. One research center in the Florida Keys is exploring a form of natural selection to keep corals remaining. The reef system in the Keys has been hit hard by climate change and pollution, which is especially tough, because corals there help support fisheries worth $ 100 million every year.

To keep the wild ecosystem alive, Erinn Muller, the center's director, and her team are harvesting samples of the corals that survived the environmental stress naturally, keeping them to make them reproduce, and then reattaching them to the reef. They have 46,000 corals on plastic frames under the sea. So far, the center has regrown over 70,000 corals from five different species on damaged reefs.

In The Bahamas, Ross Cunning, a research biologist at Chicago's Shedd Aquarium, focuses on corals with genes that could make them natural candidates for restoration projects. He published a study of two Bahamian reefs, one that survived an extreme 2015 heat wave, and one that didn't. "We think their ability to deal with these higher temperatures is built into their genes," says Cunning. There's evidence of corals evolving more quickly to resist rapidly warming climate. The big question scientists need investigate, adds Gunning, is how much more heat corals can adapt to.

【推荐3】AI(人工智能)makes our lives easier and better．Let’s see the amazing AI.