Schools in US are huge consumers of energy. According to ENERGY STAR, K- 12 schools spend more than $6 billion every year on energy, far more than the amount spent on other resources, and at least 30 percent of this energy is used inefficiently or needlessly.

Realizing that, some schools are seeking measures to save energy in several ways, from low-cost adjustments, such as turning off lights in unused rooms, to large-scale projects, such as turning to green equipment.

As solar energy is becoming a more financial choice for powering buildings, more schools are making the move toward the renewable energy and using solar panels(太阳能电池板)on their rooftops. According to an online solar marketplace EnergySage, schools have their strong points to use solar energy. They often have the kind of enough space, suitable locations that are perfect for setting up solar panels.

In September 2020, a nonprofit Generation180 released its third edition of a study on solar use in US schools. The findings showed that more than 7, 300, or 55 percent, of K- 12 public and private schools used solar energy, the number has increased by 81 percent since 2014.

They also described how solar schools were saving millions in energy bills, and provided several cases to show the increased savings achieved by solar-powered school districts. For ex- ample, an Arkansas school district used its every year's energy savings of nearly $100, 000 to increase its teachers' salaries.

The Interstate Renewable Energy Council, which tracks the number of K- 12 schools with solar equipment and helps schools go solar, says on its website that schools with solar setups have an opportunity to educate students about clean energy, and show them that they are de- voted to do something for students' and the planet's health and future.

Third-party ownership also makes funding for 79 percent of schools to use solar energy possible, meaning a majority of schools don't have to spend large amounts of money but can get the rewards of solar energy.

Plastic remains one of the most-used materials for making many of the things we use in our everyday lives. Things made of plastic can be very strong and last a long time. They also do well in extreme heat and cold. Plastic is also much lighter than metal and can be easily formed into different shapes. This makes the material perfect for the uses across many different industries

But the widespread use of plastics is causing major problems for the environment. Plastic materials are causing serious damage to the world’s oceans.

Plastics can take hundreds of years to break down on their own. Very few kinds are highly recyclable. This is because of the way plastics are formed. Even when recycling is possible, the process is costly and can use a lot of energy.

But a team of researchers working at the U.S. Department of Energy say they have created a kind of plastic that could lead to products that are 100 percent recyclable.

The researchers say the new material is a plastic polymer(聚合物)called polydiketoenamine, or PDK. The team reports that the material can be broken down in parts at the molecular(分子的) level. It can then be built up again to form plastics of different shapes, colors and more. The researchers say this process can be repeated over and over again -without the plastic material losing any performance or quality.

“Most plastics were never made to be recycled,” lead researcher Peter Christensen said. “But we have discovered a new way to make plastics that takes recycling into consideration from a molecular point of view. Then we would be able to remove plastics from the oceans. It’s going to be a really exciting time.”

Many robots track objects by “sight” as they work with them, but optical (视觉的) sensors can’t take in an item’s entire shape when it’s in the dark or partially blocked from view. Now a new low-cost technique lets a robotic hand “feel” an unfamiliar object’s form — and skillfully handle it based on this information alone.

Roboticist, Xiaolong Wang in University of California, San Diego and his team wanted to find out if complex coordination (协调) could be achieved in robotics using only simple touch data. The researcher attached 16 contact sensors, each costing about $12, to the palm and fingers of a four -fingered robot hand. These sensors simply indicate if an object is touching the hand or not. “While one sensor doesn’t catch much, a lot of them can help you capture different aspects of the object,” Wang says. In this case, the robot’s task was to rotate (旋转) items placed in its palm.

The researchers first connected a large volume of touch data as a virtual robot hand practiced rotating objects, including ball. Using binary contact information (“touch” or “no touch”) from each sensor, the team built a computer model that determines an object’s position at every step of the handling process and moves the fingers to rotate it smoothly and stably.

Next they transferred this capability to operate a real robot hand, which successfully manipulated (操纵) previously unencountered objects such as apples, tomatoes, soup cans and rubber ducks. Transferring the computer model to the real world was relatively easy because the binary sensor data were so simple; the model didn’t rely on accurate measurements.

Digging into what the robot hand perceives, Wang and his colleagues found that it can re-create the entire object’s form from touch data, informing its actions. He and his team are set to present thier handiwork at an international conference called Robotics: Science and Systems.

New York University’s Lerrel Pinto, who studies robots’ interactions with the real world, wonders whether the system would become less effective at more complicated tasks including opening a bottle cap. Wang’s group aims to tackle more complex movements in future work as well as to add sensors in places such as the sides of the fingers. The researchers will also try adding vision to improve touch data for handling complicated shapes.