【推荐1】Don't get mad the next time you catch your teenager texting when he promised to be studying. He simply may not be able to resist. A University of lowa(UI) study found teenagers are far more sensitive than adults to the immediate effect or reward of their behaviors. The findings may help explain why the initial rush of texting may be more attractive for adolescents than the long-term pay off of studying.

"For the teenager, 'the rewards are attractive." says Professor Jatin   Vaidya，an author of the study. "They draw adolescent. Sometimes, the rewards are a kind of motivation for them. Even when a behavior is   no   longer in a teenager's best interest to continue, they will, because the effect of   the reward is still there and lasts much longer in adolescents than in adults ."

For parents,that means limiting distraction (分心的事情）so teenagers can make better choices. Take the homework and social media dilemma: At 9 p.m., shut off   everything except a   computer that has no access to   Facehook or Twitter, the researchers advise. "I'm not saying they shouldn't be allowed access to technology," Vaidya says. But some help in netting their concentration is necessary for them   so they can develop those impulse-control skills.”

In their study,Vaidya and co-author Shaun Vecera note researchers generally believe teenagers are impulsive（冲动的)，make bad decisions，and engage in risky behavior because the frontal lobes（额叶）of their trains are not fully developed. But the UI researchers wondered. whether something more fundamental was going on with adolescents to cause behaviors independent of higher-level reasoning.

"We wanted to try to understand the brain's reward system how it change from chillhood to adulthood," Says Vaidya, who adds the reward character in the human brain is easier than decision-making. “We've been trying to understand the reward process in adolescence and     whether there is more to   adolescence behavior than an under-developed frontal   lobe,”he adds.For their study ,the researchers persuaded 40 adolescents, aged 13 and 16,and 40 adults, aged 20 and 35 to participate.

In the future,researchers hope to look into the psychological and neurological（神经学上的）aspects of their results.

【推荐2】Before the age of the smartphone, photographers had to learn how to use high-tech cameras and photographic techniques. Today, with the huge range of camera apps on our smartphones, we’re all good amateur photographers, since the quality of smartphone images now nearly equals that of digital cameras.

The new ease of photography has given us a tremendous appetite for capturing the magical and the ordinary. We are obsessed with documenting everyday moments, whether it’s a shot of our breakfast, our cat or the cat’s breakfast. Even photo journalists are experimenting with mobile phones because their near invisibility makes it easier to capture unguarded moments.

In the past, magazines published unforgettable photos of important people and global events that captured our imaginations. These photos had the power to change public opinion and even the course of history. But if there are fewer memorable images today, it’s not because there are fewer good images. It’s because there are so many, and no one image gets to be special for long.

As people everywhere embrace photography and the media make use of citizen journalists, professional standards appear to be shifting. Before digital images, most people trusted photographs to accurately reflect reality. Today, images can be altered in ways the naked eye might never notice. Photojournalists are trained to accurately represent what they witness. Yet any image can be altered to create an “improved” picture of reality. The average viewer is left with no way to assess the accuracy of an image except through trust in a news organization or photographer.

The question of the accuracy of images gets even trickier when photojournalists start experimenting with camera apps-- like Hipstamatic or Instagram --- which encourage the use of filters （滤镜）. Images can be colored, brightened, faded, and scratched to make photographs more artistic, or to give them an antique look. Photographers using camera apps to cover wars and conflicts have created powerful images--- but also controversy. Critics worry that antique-looking photographs romanticize war, while distancing us from those who fight in them.

Yet photography has always been more subjective than we assume. Each picture is a result of a series of decisions-- where to stand, what lens to use, what to leave in and what to leave out of the frame. Does altering photographs with camera app filters make them less true? There’s something powerful and exciting about the experiment the digital age has forced upon us. These new tools make it easier to tell our own stories--- and they give others the power to do the same. Many members of the media get stuck on the same stories, focusing on elections, governments, wars, and disasters, and in the process, miss out on the less dramatic images of daily life that can be as revealing.

Who knows? Our obsession with documentation and constantly being connected could lead to a dramatic change in our way of being. Perhaps we are witnessing the development of a universal visual language, one that could change the way we relate to each other and the world. Of course, as with any language, there will be those who produce poetry and those who make shopping lists.

【推荐3】Cao Yuan, a PhD student from China, had two papers published on strange behaviour in atom-thick layers of carbon that have opened up a new field of physics.

Pablo Jarillo-Herrero’s group at MIT was already layering and rotating (旋转) sheets of carbon at different angles when Cao joined the lab in 2014. Cao’s job was to find out what happened when one graphene (石墨烯) sheet was twisted only slightly wiht respect to the other, which one theory predicted would thoroughly change the material’s behaviour.

Many physicists doubted the idea. But when Cao set out to create the subtly twisted stacks, he spotted something strange. Exposed to a small electric field and cooled to 1.7 degrees above absolute zero, the graphene—which ordinarily conducts electricity—became an insulator. That by itself was surprising. But the best was yet to come: with a slight change to the field, the twisted sheets became a superconductor, in which electricity flowed without resistance.

The ability to get atom-thick carbon into a complex electronic state through a simple rotation now has physics demanding to engineer exciting behavior in other twisted 2D materials. Some even hope that graphene could shed light on how more-complex materials superconduct at much higher temperatures. "There are so many things we can do," says Cory Dean, a physicist at Columbia University. "The opportunities at hand now are almost irresistible."

Hitting graphene’s “magic angle”—a rotation between parallel sheets of around 1.1°—involved some trial and error, but Cao was soon able to do it reliably. His experimental skill was extremely important, says his supervisor Jarillo-Herrero. Cao pioneered a method of tearing a single sheet of graphene so that he could create a stack of two layers, from which he could then fine-tune alignment (微调校准).

Cao loves to take things apart and rebuild them. A heart, he is “a tinkerer”, his supervisor says. On his own time, this means photographing the night sky using homemade cameras and telescopes—pieces of which usually lie across Cao’s office. "Every ime I go in, it’s a huge mess, with computers taken apart and pieces of telescope all over his desk," says Jarillo-Herrero.