1 . China has just officially opened its FAST radio telescope to international scientists. Scientists across the world can submit proposals for astronomical observations using the telescope.

FAST is short for Five-hundred-meter Aperture Spherical Telescope (球面射电望远镜) and it is also believed to be the world's largest radio telescope and the most sensitive single-dish radio telescope. The receiving surface area of FAST is 250,000 square meters, about the size of 30 standard football fields. Its construction was completed in September 2016 and it officially began operating in January 2020.

The major scientific task of the telescope is the observation of pulsars (脉冲星) – the rotating neutron stars. The study of pulsars can help to confirm the existence of gravitational radiation and black holes, and help solve many other major questions in physics. Another scientific goal of FAST is to search for outer space civilization.

The telescope is located in a naturally deep and round karst depression in southwest China's Guizhou Province. The first advantage of the selected site is the altitude. The average altitude of Guizhou is about 1,100 meters, which maximizes the effectiveness of the observation equipment. Secondly, the radio telescope needs to have a “big pan” to receive better signal. The huge natural depression could reduce the amount of excavation (挖掘) and difficulty of construction. Moreover, the selected site in Guizhou is far away from cities, and has a small population, which reduces the interference (干扰) caused by wireless devices such as TVs, mobile phones and radios from human activities.

FAST has identified over 300 pulsars. Experts predict that the number could reach 1,000 in five years and that the telescope could locate and identify the first pulsar outside the galaxy. With the opening-up to international scientists, China's FAST is expected to make more contribution to astronomical research in the future.

2 . New parents who clean their homes very often to protect their babies from bacteria and other organisms might cut back their efforts.

A new study suggests high levels of contact with cleaning products are linked to an increased risk of the childhood breathing condition known as asthma (气喘).

Researchers asked a group of parents how often they used 26 common household cleaners during their babies’ first three to four months of life. By age three, the children who had come in contact with cleaning products the most were more likely to be diagnosed with asthma. The researchers said children who had a lot of contact with cleaners were 37 percent more likely to have asthma than children with the least contact. The study also found a lot of exposure to cleaning products caused children to be 35 percent more likely to have chronic difficulty breathing. In addition, they were 49 percent more likely to have chronic allergies.

Tim Takaro, who helped lead the study, suggested that parents should question the belief that their home is clean only if it smells like chemical-based cleaning products. He also advised them to look for products free of substances like chemical colors. Besides, they should consider natural cleaning products instead of chemical ones.

The American lung Association recommends avoiding cleaning products that contain volatile (易挥发的) organic substances and other irritants (刺激物). But companies in Canada and the United States are not required to list all the chemicals in cleaning products. Some products labeled as environmentally friendly, or "green", may contain harmful substances.

Elissa Abrams, a doctor with the University of Manitoba, admitted the effects of cleaning products are not well understood. But she believed these products and the chemicals they contain act as irritants to growing children "The take-home message is that parents should be careful with cleaning products they use in the home", she added.

3 . When it comes to making television historical documentaries, there are few places and periods that British television audiences have not been taken by presenter Michael Wood. Earlier this year he became the first filmmaker from outside China to make a film about the life and work of poet Du Fu. The Du Fu film, featuring famous British actor Ian McKellen reading his poems, was shown on the BBC and China Central Television, and the reaction was instant and positive.

“It created a lot of interest and feedback in China and got a lot of coverage at the time, which was really touching, because when you go into a foreign culture as an outsider, to make a film about something of theirs, you want to make sure you’ve got it right.” Wood said.

As shown in the documentary, Du Fu’s works are learnt by heart by Chinese school students, but outside the country, he is not that well known. So, there is something Wood is keen to put right.

Stephen Owen, one of his leading translators from Harvard says, “Du Fu should be considered alongside Shakespeare and Dante as people who helped compose the emotional vocabulary of their culture.”

For more than 40 years, China has always held the most fascination for Wood. He first got interested in China when he was at school and picked up a book called Poems of the late Tang by AC Graham. “That book opened a window to a world that I never even dreamed.” he said. In the early 80s, it was the first time he had been to China. “I really enjoyed being with the people, who were so friendly and sociable. I remember coming back from my first long trip there feeling genuinely sad to go home.” Wood said.

Opening up discussion and encouraging cultural links is something Wood also does through his involvement. “We believe in dialogue. We try to promote mutual understanding and respect, and we want to help people in the West understand the culture of China better and to get rid of major areas of misunderstanding.” he said. “I did a series called The Story of England years ago, telling the history of the country over the centuries through the life of one village, and I’d love to try something like that in China.”

4 . Students at Summer Creek and Kingwood Park High schools have joined a project called “Students Helping Veterans (退伍军人) : Big Heroes, Tiny Homes” over the past school year.

The high school’s students and teachers partnered together to create a tiny home community in the Houston area, for homeless veterans. Generous local community donations helped fund the project. Besides, the schools collaborate with architects, engineers and other community partners in the local community to design and build homes expected to be 200 to 300 square feet in size. They eventually want to build a community where veterans can be surrounded by other veteran neighbors who understand and relate to their difficulties and issues when coming back to civilian life.

As a team, the students attend regular meetings together to work on the design. They are motivated by the purpose behind the project which keeps them focusing on the tasks at hand. With every nail that goes in, they know that they are improving a veteran's life and providing him a secure home where he can spend his golden years. "The kids are doing something for someone without any reward except knowing they are doing it for someone," said Missy Tayler, their proud teacher.

"They wanted to serve their country and protect us, and they came back but they didn't get the same treatment," said senior student Sarah Dalby, describing her motivation to help. She added that when she started the project, she barely knew how to use a saw but she is a fast learner and loves the work. “You have to appreciate the armed forces of our country for giving us the individual liberties that we enjoy,” senior student, Nicolas Logan said when explaining his own motivation to participate in the project.

5 . China’s Chang’e 5 mission to the moon was completed in less than a month after blasting off (点火起飞). A capsule containing samples of lunar (月球的) rocks and soil collected from the surface of our natural satellite landed in Inner Mongolia, where it was taken back for study.

Chinese broadcaster CGTN reported that the capsule had landed back to Earth just after 10am Dec. 16. Search crews were out in the freezing pre-dawn Hours looking to find back the capsule from the snowy grassland during temperatures well below zero. Aerial images (航拍影像) appeared to show the capsule safely resting on the ground.

China's National Space Administration announced on Thursday, Dec. 3, that its ascent module (上升器) had blasted off from the top of the mission's lunar lander, carrying samples of rock and soil it dug from the lunar surface. It then met with an orbiter circling the moon. The pair made the return trip to Earth where the capsule carrying the samples was sent on its way for a hot and fast going down through our atmosphere only to land on the frozen ground.

The mission lifted off from China on Nov. 23 and landed on the moon on Dec. l. Videos from Chinese media showed the lander’s robotic arm hard at work during its short shift on another world. During its stay, Chang'e 5 also sent back images of a lunar plain of relatively young volcanic moon rock. The image shows both distant hills and how the feet of the lander dug into the soft surface of the moon as it touched down. Enlarging the foot of the lander in particular providers a real sense of the dry, desert-like lunar surface. When the samples were collected, they have been the first pieces of the moon to be returned to our planet since the 1970s.

6 . Identical twins (同卵双胞胎) may not be exact copies at the DNA level after all. Normally, identical twins differ by 5. 2 genetic changes. Researchers shared their new finding in Nature Genetics.

Identical twins are also called monozygotic twins (单卵双胞胎). They come from a single egg. That egg forms an embryo (胚胎). Then, it splits into two embryos. Each of these embryos will go on to become a baby.

Identical twins have long been thought to have the exact same genes. That's why some scientific studies study these twins. Such studies try to determine whether particular features, diseases or conditions are due to genes or instead reflect environmental influences. Any differences in the health of identical twins were thought to be due to different environmental exposures. The new findings, though, suggest that genetic changes might also explain why identical twins aren't truly identical.

Researchers in Iceland studied 381 pairs of identical twins. Then the scientists studied all the genes in each person carefully. Only 38 pairs of twins had all the same genes. Most twin pairs differed somewhat in their DNA. Those differences likely arose long before birth. It could have happened either just before one embryo split to form two or it could have happened shortly after the split. Some of the twins had many genetic differences. Thirty-nine pairs had more than 100 differences in their genes.

Gene changes, or mutations (突变), seen in the newly studied twins suggest that embryos don’t split neatly in half when twins form. Some twins may arise when a single cell or a small group of cells splits off from an embryo. How many cells each twin originates from may determine how genetically different they are. More uneven splits of the embryo may lead to a greater number of gene differences in the twins.

7 . International UN Volunteer Program 2021

If you are interested and ready to become a UN volunteer, you can join a million volunteers to register and become an international volunteer through any of the available opportunities cutting across a wide range of professions. UN volunteer job is available to the volunteers from any part of the globe. You can contribute your time, skills and knowledge through volunteering with the UN. This is an opportunity to create a positive impact and be a significant force for achieving peace and development.

What it involves

The International UN Volunteers promote peace and development in communities around the globe, while supporting the ideals and aspirations (抱负) of the United Nations.

Volunteers come from 160 countries, representing many cultures and backgrounds. They bring a wide variety of perspectives (观点) and approaches.

As a volunteer, you can learn about different cultures, expand your networks, study foreign languages and gain professional and life experiences.

Requirements for becoming a UN volunteer

*25 years old or older (no upper age limit).

* University degree or higher technical diploma (文凭).

*Two years of relevant volunteer experience in a professional background will gain the priority to be employed.

* Good working knowledge of at least one of UNV's three working languages: English, French or Spanish.

* Ability to work in a multicultural environment.

* Willingness to work with people and local organizations to draw upon the synergies (协同作用) between expert solutions and local knowledge.

* Ability to adjust in difficult living conditions and sometimes remote locations.

* Strong interpersonal and organizational skills.

8 . Researchers at CU Boulder have developed a wearable device that changes the human body into a biological battery. The device is stretchy(弹性的) enough that you can wear it like a ring, sport band or any other thing that touches your skin. It also taps into a person's natural heat-employing thermoelectric generators to change the body's internal temperature into electricity. "In the future, we want to be able to power your wearable electronics without having to include a battery," said Jianliang Xiao, an associate professor at CU Boulder.

The concept may sound like something out of The Matrix film series, in which a race of robots have enslaved humans to harvest their precious organic energy. Xiao and his colleagues aren't that ambitious: Their devices can generate about 1 volt (伏特) of energy for every square centimeter of skin space-less volt per area than what most existing batteries provide but still enough to power electronics like watches or fitness trackers.

Scientists have previously experimented with similar wearable devices, but Xiao's is stretchy, can heal itself when damaged and is fully recyclable-making it a cleaner alternative to traditional electronics. "Whenever you use a battery, you're depleting(消耗) that battery and will, eventually, need to replace it," Xiao said. "The nice thing about our device is that you can wear it, and it provides you with constant power."

Just pretend that you're out for a jog. As you exercise, your body heats up, and that heat will radiate out to the cool air around you. Xiao's device captures that flow of energy rather than let it go to waste. "The thermoelectric generators are in close contact with the human body, and they can use the heat that would normally be sent into the environment," Xiao said.