A team of engineers at Harvard University has been inspired by Nature to create the first robotic fly. The mechanical fly has become a platform for a series of new high-tech integrated systems. Designed to do what a fly does naturally, the tiny machine is the size of a fat housefly. Its mini wings allow it to stay in the air and perform controlled flight tasks.

    “It's extremely important for us to think about this as a whole system and not just the sum of a bunch of individual components (元件),” said Robert Wood, the Harvard engineering professor who has been working on the robotic fly project for over a decade. A few years ago, his team got the go-ahead to start piecing together the components.“The added difficulty with a project like this is that actually none of those components are off the shelf and so we have to develop them all on our own,” he said.

    They engineered a series of systems to start and drive the robotic fly. “The seemingly simple system which just moves the wings has a number of interdependencies on the individual components, each of which individually has to perform well, but then has to be matched well to everything it's connected to,” said Wood. The flight device was built into a set of power, computation, sensing and control systems. Wood says the success of the project proves that the flying robot with these tiny components can be built and manufactured.

    While this first robotic flyer is linked to a small, off-board power source, the goal is eventually to equip it with a built-in power source, so that it might someday perform data-gathering work at rescue sites, in farmers' fields or on the battlefield. “Basically it should be able to take off, land and fly around,” he said.

    Wood says the design offers a new way to study flight mechanics and control at insect-scale. Yet, the power, sensing and computation technologies on board could have much broader applications. “You can start thinking about using them to answer open scientific questions, you know, to study biology in ways that would be difficult with the animals, but using these robots instead,” he said. “So there are a lot of technologies and open interesting scientific questions that are really what drives us on a day to day basis.”

    Zebra crossings－the alternating dark and light stripes on the road surface－are meant to remind drivers that pedestrians may be trying to get across. Unfortunately, they are not very effective. A 1998 study done by the Department of Traffic Planning and Engineering at Sweden's Lund University revealed that three out of four drivers maintained the same speed or even speeded up as they were approaching a crossing. Even worse, only 5% stopped even when they saw someone trying to get across.

    Now a mother-daughter team in Ahmedabad, India has come up with a clever way to get drivers to pay more attention－a 3-D zebra crossing with an optical illusion (视错觉).

    Artists Saumya Pandya Thakkar and Shakuntala Pandya were asked to paint the crosswalks by IL&FS, an Indian company that manages the highways in Ahmedabad. The corporation was looking for a creative solution to help the city's residents to cross the busy accident-prone  (易出事故的) roads safely. Thakkar and Pandya, who had previously seen images of 3-D zebra crossings that gave drivers the illusion of logs(原木)of wood on the streets in Taizhou, China, decided to test if a similar way would work in India.

    Sure enough, in the six months that the 3-D crosswalks have been painted across four of the city's most dangerous highways, there have been no accidents reported! The artists say that while it may appear that the zebra crossing could cause the drivers to brake suddenly and endanger the vehicles behind, such is not the case. Because of the way the human eye works, the illusion is only visible from a distance. As they get closer, the painting looks just like any other ordinary zebra crossing. The creators hope that their smart design will become increasingly common throughout India and perhaps even the world. So let's look forward to it.

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    Free energy is everywhere around us. There are many ways to make and collect energy from various sources like sun, wind and water. People also realize that everyday stuff can be a source of energy too. For example, riding a bike, running or just walking, etc. We simply have to change our way of thinking if we want to change the world.

    So comes the idea of solar roadways. Are they the road of future? Why use roads just for driving and collecting tolls (过路费)? Why don't we use them for collecting energy?

    The US Department of Transportation recently awarded $100,000 to Solar Roadways to build the first ever Solar Road Panel. So how do these future roads work?

    The Solar Road Panels will contain embedded (嵌入的) LEDs which “paint” the road lines from beneath to provide safer nighttime driving as well as to give drivers instant instructions such as detour (绕行) ahead. The road will be able to sense wildlife on the road and can warn drivers to “slow down”. There will also be embedded heating elements in the surface to prevent snow and ice buildup, providing safer winter driving.

    Replacing asphalt (沥青) roads and parking lots with Solar Roadway Panels will be a major step toward stopping climate change. Fully electric vehicles will be able to recharge along the roadway and in parking lots, finally making electric cars practical for long trips.

    We just can't wait to see more of these roads all over the world in the near future.

    While elephants born without tusks (长牙)are not unheard of，they normally form just 2 to 6 percent of the population. However, that is not the case at Mozambique's Gorongosa National Park, where an astonishing 33 percent of female elephants born after the country's civil war ended in 1992 are tuskless. While that may appear to be just a coincidence, Joyce Poole, an elephant behavior expert, has another theory. The researcher thinks we may be witnessing unnatural evolution of the species due to the constant hunting of elephants for valuable ivory.

    Poole says before the country's 15-year-long civil war, the 100,000-acre park was home to over 4,000 elephants. However, by the time the conflict ended in 1992, about 90 percent of them had been killed for ivory to help finance weapons (武器)and meat to feed the soldiers. Of the less than 200 survivors, over 50 percent of adult females had no tusks. Therefore, it is not surprising that the park's tuskless elephant population has grown greatly.

    This is not the first time researchers have observed a great change in the population of elephants. At Zambia's South Luangwa National Park and Lupande Game Management Area， areas which were heavily hunted in the 1970s and 1980s, 35% of elephants 25 years or older and 13% of those younger than 25 are now without tusks. A 2008 study published found that the number of tuskless females at the Ruaha National Park in Tanzania went from 10.5 percent in 1969 to almost 40 percent in 1989, largely due to illegal hunting for ivory.

    The recent ban on ivory in both the US and China should help get rid of, or at least reduce, elephant hunting. However, scientists are not sure how long it will take for elephants with a higher rate of tuskless females, to change the trend.

Foldable phones are once again facing questions about their durability(耐久性).The Galaxy Z Flip and the Motorola Razr are now both available to buy in the US-but early reports suggest the screens are easily damaged.

One media published photos of two layers of the Razr's display separating, affecting the touch screen. The Galaxy flip, meanwhile, boasts(自夸)a "flexible glass" display—but tests appear to show it scratching(刮擦)as easily as plastic.

In a statement, Samsung said the display had a protective layer, and had undergone extensive testing. "While the display does bend, it should be handled with care, "it said.

The Z Flip's "pretty thin glass" is one of Samsung's primary marketing messages for the new phone. But a durability test conducted by popular Zack Nelson, a regular buyer, suggested it was no more durable than soft plastic screen, and could even be dented(痕)by fingernail.

Nelson said Samsung's screen scratched exactly how plastic screen would react. "I don't know what material this is, but Samsung definitely shouldn't be calling it glass," he said. He found that the screen of the Motorola Razr scratched as easily but it is not marketed as "glass".

The Motorola Razr was put on sale 13 days ago in the US, but Raymond Wong, an editor says the flexible screen on his handset has already broken. The upper layer of the Razr's screen separated from the bottom, creating "a giant horizontal air bubble" for no apparent reason. He wrote that the fault appeared after 45-minute train ride during which the phone was in his pocket. The screen was completely warped from hinge-to-hinge with the top layer raised like a poorly applied screen protector. But Mr. Wong said that apart from the visual problem, the damage has affected the responsiveness of the touchscreen.

Must-see in Guangxi

A Hotel in Nature

Chaoranpai International Hotel is only 2 kilometers away from the Lijiang River Source Grand Canyon. By taking both the ecological design and standards of 5-star hotels into account, this hotel has integrated modern services with nature, especially bamboo. The hotel also offers entertainments such as go-carting, cosplay of counter strike (反恐精英), and Chinese-style tea houses. Besides, the mountain itself is like a natural oxygen bar. 

Hemlock Spruce—a Living Fossil from the Ice Age

Hemlock spruces (铁杉树) are found at altitudes (海拔) between 1, 600 and 1, 800 meters, with one area recognized as China's only hemlock spruce forest, having as many as 130 of them. Hemlock spruce, along with dawn redwood and ginkgo (银杏), is "a living fossil". Immune (免疫) to all cold-weather risks, it stays green throughout the year. 

A Heaven of Animals and Plants

Mao'er Mountain is rich in rare animals and plants. Inhabited (栖息) by 2, 484 species of plants and 345 species of vertebrates, this place can serve as a natural gene bank. And surprisingly, a rare alpine wetland featuring evergreen broad-leaved trees has found a way of surviving in the dwarf forest at a high altitude. 

The "Millennium Kiss" Wonder

It's a miracle that two trees have existed together and grown for around a thousand years. It's even more breathtaking to see the two trees gradually getting close to each other and having a little "kiss". What a lovely sight it is in the natural beauty of Mao'er Mountain!