【推荐1】In WALL-E, a science fiction movie, a little robot is responsible for cleaning a world covered in garbage; a world where there is no longer room for anything else, not even humans! The film encourages common people, worldwide leaders and businessmen to ask the obvious question: What can be done to prevent something like this happening? For some, microfactories could become the most promising answer.

Veena Sahajwalla, a materials scientist and engineer in Sydney, Australia, has discovered a solution to the challenging waste problem. Her one-stop approach could go beyond the existing recycling processes. Her waste microfactories mainly target electronic waste and plastic, and are essentially small-sized trash processors. These can transform waste into new materials with the help of thermal (热的) technology.

“Using our green manufacturing technologies, these microfactories can transform waste, enabling local businesses and communities to not only solve local waste problems, but to develop a commercial opportunity from the valuable materials that are created,” she explains.

Humans generate 2.01 billion tons of solid waste annually. And as the fastest growing waste stream, roughly 53.6 million tons of e-waste was generated globally by 2019. Despite current efforts, only 17.4 percent of this is known to have been collected and properly recycled. Meanwhile, worldwide e-waste generation is expected to continue to grow, reaching almost 80 million tons by 2030.

Although the most effective solution to the waste challenges would not generate as much trash, Sahajwalla’s microfactories provide hope for all the waste that already exists. Her solution not only attenuates the amount of waste, but it also improves its management and enables new manufacturing opportunities around the new materials created.

WALL-E shows us the best and the worst of what human beings have to offer. It shows where the world is heading unless the human species slows down and stops developing at the current pace. But it also provides hope, showing that we also have a great power to change and improve.

【推荐2】Human tears could carry a flood of useful information. With just a few drops, a new technique can spot eye disease and even glimpse signs of diabetes(糖尿病), scientists report in ACS Nano.

“We wanted to demonstrate the potential of using tears to detect disease,” says Liu Fei, a biomedical engineer at Wenzhou Medical University in China. It's possible that the t cars could open a window for scientists to look into the entire body, he says, and one day even let people quickly test their tears at home.

Tears contain tiny sacs(囊) stuffed with cellular(细胞的) messages. If scientists could capture these microscopic mail bags, they could offer new information on what's happening inside the body.

But collecting enough of these sacs is tricky. Unlike fluid from other body parts, just a trickle of liquid leaks from the eyes.

So Liu's team invented a new way to get the sacs from tiny volumes of tears. First, the researchers collected tears from study participants. Then, the team added a solution containing the tears to a device with two nanoporous membranes(纳米多孔膜), shook the membranes and sucked the solution through. Within minutes, the technique lets small molecules(分子) escape, leaving the sacs behind for analysis. The result surprises scientists very much. Different types of dry-eye disease left their own molecular fingerprints in people's tears, the team found. What's more, tears could potentially help doctors monitor how a patient's diabetes is progressing.

Now, the scientists want to make use of tears for evidence of other diseases as well as depression or emotional stress, says study coauthor Luke Lee, a bioengineer at Harvard Medical School. “This is just the beginning.” he says, “Tears express something that we haven't really explored.”

【推荐3】Google’s self-driving car is designed to work without a gas pedal (踏板) or steering wheel (方向盘). Now, the company has decided that the car doesn’t have any windscreen wipers either, because there’s no need for passengers to see where they are being driven.

The car requires no input from a driver, except telling it the destination. There is no driving in the way we know it and all people inside the cars will be passengers who can spend their time paying no attention to the road. While the car may not need windscreen wipers, the absence of them may make passengers feel helpless if they are unable to see where they are going clearly.

Google’s two-seater “bubble” cars have buttons to begin and end the drive, but no other controls. An on-board computer uses data from sensors, including radar (雷达) and cameras, to make turns and keep away from people walking in the street and other vehicles. Under the vision made public by Google, passengers might set their destination by typing it into a map or using voice commands. The new car can’t go faster than 25 miles per hour (40 km/h). It is electric and has to be recharged after 80 miles (129 km). They can only be used in areas that have been thoroughly mapped by Google.

Google has been testing its self-driving cars since 2009 and its new model without a steering wheel since early this summer. It intends on making its driverless cars available to consumers in the next five years. The final goal of the project is computer-controlled cars that can get rid of human error, which results in about 90 percent of the 1.2 million road deaths worldwide each year and it was also inspiring to start with a blank sheet of paper.

【推荐3】Dunhuang is the top tourist city in China. Its key points of interest and natural sights are shockingly beautiful and able to tug at one’s heart. The Pearl of the Silk Road, Dunhuang, opens her arms to welcome tourists from all over the world.

Mogao Caves

Located 25 kilometers southeast of Dunhuang, Mogao Caves is regarded as the best Buddhist spot in China, perhaps in the whole world. The artistic features of the treasured Buddhist murals (壁画) represent perfectly the artistic style of the Northern Wei (386-543) Sui (581-618) and Tang (618-907) dynasties.

Yumenguan Pass

Situated 90 kilometers northwest of the city, the Yumen Pass was an important gateway to the western region in ancient times. Yumen Pass, Hecang Town and Han Great Wall (Han Dynasty) are the major sights in this area. Since the Yumen Pass is a distance from Dunhuang, one can have a feel of the desolation (荒凉) of western China.

Crescent (新月) Lake

Five kilometers southwest of the city, the Crescent Lake lies in the arms of Echoing-Sand Mountain, appearing clear and beautiful. The lake is crescent-shaped, hence the name. It’s surrounded by quicksand. Although it’s quite windy sometimes, the lake has never been covered by the sand. It’s really a marvelous scene in the desert.

Echoing-Sand Mountain

Five kilometers south of the city, Echoing-Sand Mountain is the accumulation of years of sand in the size of rice. Each time the wind blows, there is a sound from the mountain and when there is a breeze, the sound is like musical instruments, hence the name. The most marvelous experience is when after climbing to the top, although quite tough, one can slide down to the foot of the mountain, a wonderfully amusing experience!

【推荐1】What is the future of AI (人工智能)? Will it be a good thing? We asked four students what they think.