【推荐1】Batteries can power anything from small sensors to large systems. While scientists are finding ways to make them smaller but even more powerful, problems can arise when these batteries are much larger and heavier than the devices themselves. University of Missouri(MU) researchers are developing a nuclear energy source that is smaller, lighter and more efficient.

“To provide enough power, we need certain methods with high energy density(密度)”, said Jae Kwon, assistant professor of electrical and computer engineering at MU. “The radioisotope(放射性同位素) battery can provide power density that is much higher than chemical batteries.”

Kwon and his research team have been working on building a small nuclear battery, presently the size and thickness of a penny, intended to power various micro / nanoelectromechanical systems (M/NEMS). Although nuclear batteries can cause concerns, Kwon said they are safe.

“People hear the word ‘nuclear’ and think of something very dangerous,” he said, “However, nuclear power sources have already been safely powering a variety of devices, such as pace-makers, space satellites and underwater systems.”

His new idea is not only in the battery’s size, but also in its semiconductor(半导体). Kwon’s battery uses a liquid semiconductor rather than a solid semiconductor.

“The key part of using a radioactive battery is that when you harvest the energy, part of the radiation energy can damage the lattice structure of the solid semiconductor,” Kwon said, “By using a liquid semiconductor, we believe we can minimize that problem.”

Together with J. David Robertson, chemistry professor and associate director of the MU Research Reactor, Kwon is working to build and test the battery. In the future, they hope to increase the battery’s power, shrink its size and try with various other materials. Kwon said that battery could be thinner than the thickness of human hair.

【推荐2】You wait 50 years for a flying car,and then three come along at once.First up is Vahana:an airbus project to develop batterypowered,single- seater aircraft,designed to follow predetermined routes,only changing directions to avoid accidents.Propellers(螺旋桨)on the wings will let it take off and land without a runway.

Second,Dubai recently announced plans to use self-controlled air taxis as a way to beat the terrible traffic jams.The Volocopter is an electric multi-copter with 18 propellers and a fully self-controlled system.It’s essentially a self-controlled aircraft with two seats and up to 30 minutes of flying time.

But,if you want something more like the flying cars of 1950s science fiction,try Urban Aeronautics’ Fancraft.The Israel-based company wants to realize the dream of”an aircraft that looks like the classic vision of a flying car:doesn’t have a wing,doesn’t have a propeller that can be seen,and can fly exactly from point to point,”says Janina Frankel-Yoeli,Urban Aeronautics’ vice president of marketing.Earlier flying cars needed runways to take off and land which was,as Frankel-Yoeli says,”not much better than owning a car and an aircraft.”To go from point to point requires vertical take-off and landing,but for many years that could only be done by helicopters or larger aircraft.Urban Aeronautics’ solution is to use light but powerful engines,lightweight materials,and a self-controlled system.Their fan design-propellers housed in some special tubes-is powerful but unstable,so the Fancraft would be challenging for a human to fly without any help.Instead,computer-aided control technology takes over the tiny,quick changes required to keep the car stable at speeds of 160km/h or more.

But don’t be glad too early yet.The main problem to a sky full of flying cars is rules.Not only will every aircraft need to pass strict safety tests,but a new system of air traffic control will be needed to deal with 3-D traffic jams above people who are not aware of what is happening in the sky.NASA is already working on that.Tests have shown that multiple unmanned(无人的) flying cars can communicate with each other to avoid accidents.In the meantime,flying cars will mainly be reserved for emergency services and a few VIPs.

【推荐2】The Notre Dame (巴黎圣母院) fire has been put out, but its spire (尖顶) and a large portion of its wooden roof have been damaged. The terrible destruction causes a sudden sharp pain to people around the world. “What a pity that we cannot see the damaged parts of the wonder anymore.”

But the good news is that there is at least one way of seeing them, namely through a video game called Assassin’s Creed: Unity. In this game, the player can travel to one city after another and enter the buildings exactly like what they are in reality, and see Notre Dame as it was before the fire. Further, with virtual reality technology, which is already quite mature, one can even look around the undamaged Notre Dame as if it is still there. Maybe digital technology could help to better protect architectural cultural heritage.

The idea of making digital models of ancient buildings to save their data dates back to the 1990s and the necessary technology has continued to advance since then. By scanning the ancient buildings with lasers, building 3D models with multiple images, as well as measuring everything precisely, engineers can make a copy as accurate as the real one.

As computers and smartphones are hugely popular, the digital model has great useful value. First, it allows tourists to feel the cultural relics without touching them. The virtual tour of Dunhuang Grottoes in Gansu Province is a good example of this as tourists can view the paintings without standing near them. Furthermore, it can make the digitized cultural relics more famous by spreading awareness about them via the Internet. In 2000, a virtual tour of the Great Wall became very popular at the Hannover World Expo, which increased the number of foreign tourists visiting the site in the following years. Above all, it preserves all the information of the cultural relics.

Maybe we will have better technologies in the future, but the digital technology offers a practical way to preserve architectural cultural heritage at the moment.