【推荐1】If you have flown with JetBlue or Delta airlines lately, you might recall a new program that allows passengers to board their flights with a facial recognition scan. However, you might not have known that these systems were also the first stage of the Department of Homeland Security’s (DHS) “Biometric Exit” program, which has been in place since June of last year, Slate reports.

According to Slate, the DHS has partnered with Delta to make face recognition scans mandatory (强制的) for certain international flights leaving Atlanta and New York. DHS is also working with JetBlue to develop a similar system for travelers flying from Boston to Aruba.

So, how does it work? Essentially, computers “match passport and visa photos of U.S. visa holders to photos taken at the airport from which they’re departing the country,” Mashable says. “This helps the U.S. make sure the people getting on the plane are the same people who hold those visas.”

Still, the two programs are slightly different. The Delta system compares a photo of the passenger’s face, taken by a kiosk (信息服务亭) at the boarding gate, to photos from State Department databases. It also checks passengers’ citizenship or immigration (移民) status. If you’re flying with JetBlue, you can voluntarily get your face scanned instead of using a physical ticket.

And these systems aren’t going away anytime soon; in fact, the program is expected to expand in the coming years. Homeland Security is currently negotiating to make face recognition a common feature across all American TSA security checkpoints, says U.S. Customs and Border Protection executive John Wagner.

【推荐2】Microsoft has developed a new smart phone app that interprets eye signals and translates them into letters, allowing people with motor neurone disease to communicate with others from a phone.

The GazeSpeak app combines a smartphone’s camera with artificial intelligence to recognize eye movements in real time and convert(改变) them into letters, words and sentences.

For people suffering from ALS（渐冻症）, also known as motor neurone disease, eye movement can be the only way they are able to communicate.

“Current eye-tracking input systems for people with ALS or other motor impairments are expensive, not robust under sunlight, and require frequent re-calibration and substantial, relatively immobile setups,” said Xiaoyi Zhang, a researcher at Microsoft who developed the technology.

“To mitigate the drawbacks…we created GazeSpeak, an eye-gesture communication system that runs on a smartphone, and is designed to be low-cost, robust, portable and easy to learn.”

The app is used by the listener by pointing their smartphone at the speaker. A chart that can be stuck to the back of the smartphone is then used by the speaker to determine which eye movements to make in order to communicate.

The sticker shows four grids(方格) of letters, which each correspond to a different eye movement. By looking up, down, left or right, the speaker selects which grids the letters they want belong to. The artificial intelligence algorithm（程序） is then able to predict the word or sentence they are trying to say.

【推荐3】As a greenhouse gas,carbon dioxide-or CO2-helps warm the atmosphere. But too much of that gas has been driving an atmospheric fever. Recently, a team of researchers found a way to turn CO2 into a useful product. The researchers are turning CO2 into ethanol(乙醇) which is often added to gasoline. Although adding ethanol reduces the energy in gasoline, it offers a nice tradeoff: it helps gasoline burn more cleanly. So making ethanol from CO2 would be better for the environment.

To do that, the researchers developed a brand-new catalyst(催化剂)which could accelerate the chemical reaction. With it, the voltage(电压)needed to start the new CO2-to-ethanol reaction is far less than what's needed to start similar reactions. And although chemical reactions often make many unwanted byproducts, this new one does not. More than 90 percent of the final product is ethanol.

The new catalyst uses a bed of carbon to support copper atoms(铜原子).Those copper atoms are spread out. When electricity runs through the catalyst,copper atoms join up, forming groups of 3 or 4 atoms. By firing powerful X-rays at them, the research team could “monitor the chemical reaction as it happens”. Those atom groups activate the catalyst, helping the CO2 react with water. The CO2 now divides into carbon and oxygen atoms. And the water divides into hydrogen and oxygen atoms. All of these freed atoms now rearrange themselves to form ethanol.

Although many scientists describe the new process as “very cool”, they are still a bit skeptical. “A closer look at the reaction is needed,” chemist Anna Klinkova says. “It could be more complex than what is presented.” The researchers are continuing to experiment with the new process. They also hope to make other useful materials from carbon dioxide. “That's why the new study isn't a final step,” a researcher says. “This is just the beginning of this long research journey. ”