【推荐1】An impressive invention made by a 17-year-old teenager, called Anna Du, is helping to clean up small pieces of plastic from the ocean.

While walking along her local beaches in Massachusetts, the young student began collecting waste plastic bags and bottles. But what she noticed was a large number of tiny pieces of plastic or microplastics that were impossible to pick up. At just 12 years old, Du set out to solve the problem. After testing a few prototypes(原型)in her backyard, she invented a remotely operated vehicle that uses the infrared camera(红外摄像机)to detect microplastics on the ocean floor. More recently, Du has also created a simulation(模拟)model that uses artificial intelligence to predict where microplastics are located.

Du’s robot invention has earned her awards at top science fairs in the US, and she’s now a nationally recognized advocate for microplastic awareness and pollution prevention. “When I first started doing science fairs, I had no idea that a young girl without lots of money and just a little advanced engineering knowledge could make a difference in the world. I’ve learned that I truly love working on a problem that’s so much larger than me,” Du said.

Du has also released a new book to help spread the word not only about the dangers of microplastics but also about the ways to relieve the problem. Titled Microplastics &Me, the book follows Du’s own story of how she went from worrying about the environment to designing award-winning solutions. Writing for kids her own age, the young girl alerts her readers to the threat of microplastic pollution and urges them to care about the environment. The book hopes to encourage young students to get into science, technology, engineering and math(STEM)subjects and to inspire a new generation of inventors and engineers. What’s more, Du has even raised more than $7,000 to distribute the book free to kids and libraries in high-need communities.

【推荐2】Researchers have developed a device that turns sunlight, carbon dioxide and water into oxygen and formic acid (甲酸) — a stable fuel that can either be used directly or be changed into hydrogen, without requiring any additional components or electricity. The device, developed by a team from the University of Cambridge, is a significant step toward achieving artificial photosynthesis (光合作用).

Harvesting solar energy to turn carbon dioxide into fuels is a promising way to reduce carbon emissions. However, it is challenging to produce these clean fuels without unwanted by-products. “In addition, storage of gaseous fuels can be complicated — we want to get to the point where we can cleanly produce a liquid fuel that can also be easily stored and transported,” said Professor Eisner, senior author of the study.

In 2019, researchers from Eisner’s group developed a solar reactor based on an “artificial leaf” design, which also uses sunlight, carbon dioxide and water to produce a fuel, known as syn-gas. The new technology is quite similar to the artificial leaf but works in a different way and produces formic acid, which can be chemically converted into different types of fuel.

The artificial leaf used components from solar-cells, while the new device doesn’t require these components and relies entirely on photo-catalysts (光催化剂) placed on a sheet. The sheets are made up of semiconductor powders, which can be prepared in large quantities easily and cost-effectively. In addition, this new technology produces clean fuels that are easier to store.

“We were surprised how well it worked — it produced almost no by-products,” said Eisner. “Sometimes things don’t work as well as you expected, but this was a rare case where it actually worked better.”

The researchers are now working to further improve efficiency. Additionally, they are exploring other catalysts to get different solar fuels. “We hope this technology will pave the way toward sustainable and practical solar fuel production,” said Eisner.

【推荐3】Facial images can be used to identify signs of disease in diagnosis (诊断). For example, abnormal changes in eye movement can indicate poor visual function and visual developmental problems. However, facial images also record other information about the patients, including their race, sex, age and mood. Due to privacy concerns, people often hesitate to share their facial images for public medical research or electronic health records, blocking the development of digital medical care.

The researchers now develop a digital mask, which inputs an original video of a patient’s face and outputs a video based on the use of a deep learning algorithm (算法)and 3D reconstruction. At the same time, the digital mask can remove as much of the patient’s personal biometric (生物统计的)information as possible.

Next, the researchers tested how useful the masks were in clinical practice and found that diagnosis through the digital masks agrees with that carried out through the original videos. This suggested that the technology was accurate enough in clinical practice. The team also confirmed that the digital masks can also avoid artificial intelligence-powered facial recognition.

The team surveyed randomly (随机地)selected patients attending clinics to test their attitudes towards digital masks. Over 80% of patients believed the digital masks would ease their privacy concerns and they expressed an increased willingness to share their personal information if such a measure was carried out.

Professor Patrick from the University of Cambridge said, “Digital masks offer a practical approach to protecting information from facial images, while still allowing the information to be useful to clinicians.” This could make telemedicine-phone and video consultations, much more practicable, making healthcare delivery more efficient especially during the COVID-19 pandemic. If tele-medicine is to be widely adopted, then we need to overcome the barriers and concerns related to privacy protection. The digital mask is an important step in this direction.

【推荐3】For centuries people have wondered who was the model for Leonard do da Vinci’s Mona Lisa and what was the reason for her smile. But the Mona Lisa is just one of the many mysteries in the art world. Here are some other notable unsolved art mysteries that might be a little less familiar.

Mystery 1: Who Is the girl in Johannes Vermeer’s Girl with a Pearl Earring?

Around 1665, Dutch artist Johannes Vermeer painted a charming portrait of a young girl. People around the globe have long wondered who this fetching young lady was. Many say she must have been Vermeer’s daughter or girlfriend. Others think she wasn’t a real person, but rather an intentionally mysterious, timeless figure. The painting, referred to as the “ Mona Lisa of the North ” , has been part of The Hague’s permanent collection since 1903. But it draws record-breaking crowds whenever and wherever it tours around the world.

Mystery 2: Where Is Raphael’s Portrait of a Young Man?

Portrait of a Young Man is considered one of the most important pieces of art to go missing during World War II. The painting was created around 1513 by Raphael, a famous Italian Renaissance artist, and stolen from Poland’s Princes Czartoryski Museum in 1939.

The portrait had traveled to Germany and Austria before it was gone in 1945.

Mystery 3: Was Van Gogh Murdered?

One of the main things people know about Vincent van Gogh is that he cut off his ear. That was likely because the Dutch post-impressionist painter suffered from mental illness, probably severe depression. The official cause is suicide from a gun shot at close range.

That certainly seems plausible (貌似有理的), given his poor mental health. However, no gun was found near his body, and locals reported two teenage boys bullying him shortly before his death.