1 . Most solar panels acquire sunlight from only one side, meaning they can acquire more or less of it depending on where the sun is in the sky. In recent years, they’ve become far more effective typically turning around 22 percent of the light they acquire into energy. In a new study published in the journal Joule on Tuesday, scientists put forth a way to increase that percentage even higher: double-sided solar panels that can move to follow the sun.
Basically, these panels can acquire sun from not only their sun-facing side but also from the light reflected off the ground onto their dark undersides. At the same time, a GPS allows them to move on an axis from east to west in order to always be pointed at a best angle to acquire the sun’s rays. Though double-sided solar panels and sun-following solar panels are both in use currently, models that combine the two technologies aren’t widely available for commercial use, Solar experts predict explosive growth in the market soon, though.
The study authors determined that these two-sided sun-tracking panels produce an average of 35 percent more energy than immobile single-panel systems, and are 16 percent more cost-efficient. That holds true even when accounting for changes in weather conditions.
“This means that investing in double-sided and tracking systems should be a safe bet for the foreseeable future, Carlos Rodriguez-Gallegos,” the study’s lead author said.
The same warnings for solar panels and their effect on the local environment apply to the double-sided, moving systems as well, if not more so. Lead used in solar panels can be one source of local pollution, and Dustin Mulvaney, an associate professor of environmental studies, told Earther in an email double-sided panels could mean “twice as much lead” as traditional solar systems.
Since these new panels are more energy efficient, they could save not only money but also land. That would require restructuring how solar contracts currently work.
1. What does most solar panels rely on to acquire sunlight?| A．The amount of sunlight. | B．The location of the sun. |
| C．The quality of solar panels. | D．The size of solar panels. |
| A．The sun’s rays. | B．The panels’ undersides. |
| C．The double-sided panels | D．The panels’ sun-facing sides. |
| A．Uncertain. | B．Supportive. | C．Doubtful. | D．Subjective. |
| A．Double-Sided Solar Panels that Follow the Sun | B．Advantages of the Double-Sided Solar Panels |
| C．Application of the Double-Sided Solar Panels | D．New Trends of Double-Sided Solar Panels |
2 . If there had to be a father of handwashing in history, it would be Ignaz Semmelweis. While working at Vienna General hospital, the Hungarian doctor, faced with a situation in which maternal death (孕产妇死亡) in hospitals were significantly higher than local clinics, tried hard clues as to why.
Germs (细菌) were yet to be discovered, and it was still believed in the 1840s that disease was spread by bad smells in the air. So it didn’t seem a problem that trainee doctors hanging out of labs to dissect (解剖) human bodies would pop up to the maternity ward (产房) to deliver a baby without washing their hands.
Then an accidental finger cut by a knife during a dissection caused a doctor to die, seemingly of the same sign the mothers had been getting. Semmelweis assumed that something from the dead bodies was to blame, which might, through the hands of doctors, make their way into women’ s bodies during childbirth.
To test his theory, he ordered doctors to wash their hands and instruments in some chlorine solution. As a result, the death rate for new mothers dropped to about 1 percent, compared with that of as high as 18 percent before the experiment.
However, he faced great resistance, and met a sad end. People at that time didn’t think of themselves as sort of walking Petri dishes. And the majority of doctors then were from middle- or upper-class families, and thought of themselves as very clean people.
Over the next 40 years, a better understanding of germs developed, and attitudes to hygiene (卫生) gradually shifted. In 1876, the German scientist Robert Koch discovered the anthrax bacillus (炭疽), kicking off the new research field of medical bacteriology. Many more germs were later identified. Surgeons started to take handwashing seriously.
By the 1890s and into the early 1900s, handwashing moved from being something doctors did to something everybody had been told to do.
1. What was the situation like in the 1840s?| A．Germs might have been discovered then. |
| B．Women suffered from delivering babies then. |
| C．The air at that time was dirty and full of viruses. |
| D．People were unaware of how disease was spread. |
| A．Liquid. | B．Option. | C．Tissue. | D．Shell. |
| A．It was effective. | B．It was necessary. |
| C．It was ridiculous. | D．It was dangerous. |
| A．Steps to Protect Yourself |
| B．Disease Spreading by Your Hand |
| C．Hand Washing Critical in Fighting Viruses |
| D．The First Recorded Discovery of Handwashing |
3 . More young Chinese are making preparations for their future by buying life and medical insurance, Chen Meiling reports. Jessie Dong, 30, sent her life insurance policy to her mother, which says, if she dies before 50, family members will get a compensation (补偿)of 3 million yuan (S458,820).
Recently, the only child of her mother's colleague died at the age of 35, and all that was left to his lonely, old parents was sorrow. Dong, a researcher of social science in Beijing, says she doesn't want such a tragedy (悲剧) to happen, and hopes to be able to support her family even if she is gone. Buying insurance became one of her wisest choices.
She pays about 350 yuan every month for the life insurance, and about 300 yuan annually for critical illness insurance with coverage of 4 million yuan, in case she runs out of money for “having to treat a serious disease someday” "It's a good way to face the unpredictable risks of life with a small amount of money. Of course hopefully I won't use it," she says, adding she purchased insurance on Alipay, as she is too busy to visit insurance companies in-person, and she plans to continue investing (投资)in it.
The younger generation, those born in the 1990s, in China is showing a higher interest in buying insurance, driven by the increased awareness of crisis and a willingness to improve risk resistance ability, experts say. The fact that more people get severe diseases at a younger age or feel their worse health condition, as well as uncertainties brought about by the COVID-19 pandemic(流行病) to both their personal lives and on a Socio-economic level, also strengthens anxiety and is contributing to the trend.
1. What does the first paragraph mainly tell us?| A．The young are afraid of dying. |
| B．Jessie Dong’s mother has passes away. |
| C．Jessie gain a large sum. |
| D．Buying life insurance’s popular with the young. |
| A．By WeChat. | B．By Alipay. |
| C．In cash. | D．By Taobao. |
| A．Their serious diseases and poor health. |
| B．Their higher interest and awareness of crises. |
| C．Their life of high quality and living standard. |
| D．Their personal lives and socio-economic level. |
| A．A Future Plan | B．A Good Choice |
| C．A Health Investment | D．A Large Company |
4 . 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.
1. What does Xiao expect of his device at present?| A．It will be used for medical purposes. |
| B．It will be made smaller and wearable. |
| C．It will change natural power into electricity. |
| D．It will supply constant power to wearable devices. |
| A．To give an explanation. | B．To make a comparison. |
| C．To introduce a topic. | D．To analyze the cause. |
| A．The strengths of Xiao's device. |
| B．The convenience of using a battery. |
| C．The replacement of wearable devices. |
| D．The development of traditional electronics. |
| A．It operates with plenty of power. |
| B．It is designed for practical use. |
| C．It benefits people's health in a way. |
| D．It's based on traditional electronics. |
5 . More than half the world’s population live in cities, and by 2050 the UN expects that proportion to reach 68%. This means more homes, roads and other infrastructure. In India alone, a city the size of Chicago will have to be developed every year to meet demand for housing. Such a construction increase is a bad sign for dealing with climate change, because making steel and concrete, two of the most common building materials, generates around 8% of the world’s CO2 emissions (排放). If cities are to expand and become greener at the same time, they will have to be made from something else.
Wood is one of the most promising sustainable (可持续的) alternatives to steel and concrete. It is not, however, everyday wood that is attracting the interest of architects.
Rather, it is a material called engineered timber. This is a combination of different layers, each designed to meet the requirements of specific parts such as floors, panels and beams (横梁). Designers can use it to provide levels of strength like steel, in a product that is up to 80% lighter. In addition, engineered timber is usually made into large sections in a factory for future use, which reduces the number of deliveries to a construction site.
According to Michael Ramage of the University of Cambridge, a wooden building produces 75% less CO2 than a steel and concrete one of the same size. However, if building with wood takes off, it does raise concern about there being enough trees to go round. But with sustainably managed forests that should not be a problem, says Dr Ramage. A family-sized apartment requires about 30 cubic metres of timber, and he estimates Europe’s sustainable forests alone grow that amount every seven seconds. Nor is fire a risk, for engineered timber does not burn easily. Besides, fireproofing layers can be added to the timber. All in all, then, it looks as if wood as a building material may get a new lease of life.
1. Why is India mentioned in paragraph 1?| A．To point out the severe pollution. |
| B．To predict the population increase. |
| C．To indicate the high degree of urbanization. |
| D．To show the great need for building materials. |
| A．It is produced at a low cost. |
| B．It hardly appeals to architects. |
| C．It helps save energy in transportation. |
| D．It possesses greater strength than steel. |
| A．Becomes cheaper. | B．Gains popularity. |
| C．Requires less work. | D．Proves sustainable. |
| A．Making Future Cities More Attractive |
| B．Living in a World with Less Emission |
| C．Building Sustainable Cities with Woods |
| D．Growing More Trees for Future Building |
6 . American billionaire Elon Musk has demonstrated a technology designed to use a computer chip inside the head to control the brain. During a video demonstration on Friday, Musk provided details about the system, called Neuralink.
Musk says he hopes the technology can be used to treat neural disorders and help spinal injury victims regain body movement. Musk also believes the system could be used in the future to improve intelligence to help humans keep up with supercomputers and artificial intelligence (AI) technology.
During the show, Musk showed off a model of the Neuralink device. It is about 23 millimeters wide. It is designed to be implanted into a person's skull. Small wires would connect the device directly to the brain.
The Neuralink system is currently being tested in pigs, with plans to seek government approval for human testing sometime in the future.
A pig named Gertrude was also shown during the show. Musk explained that Gertrude had a Neuralink chip inside its head. The device is meant to record nerve activity in the pig's nose and mouth.
Musk said the company had three pigs, each with two chips. He described the animals as "healthy, happy and indistinguishable from a normal pig." Musk said the company was able to predict with "high accuracy" a pig's leg movement on a running machine using data from the chip.
Musk noted that Neuralink first wants to use the device on people with severe spinal cord injuries to help them talk and move using their brain waves. He said he is hopeful that, in the long term, those people could regain "full-body motion."
Some neuroscientists not linked to the company said the presentation suggested Neuralink had made great progress with the technology. However, they warned that many more studies will be needed to test the long-term success of such devices.
1. What good can the Neuralink device do to the disabled?| A．Making them think clearly. |
| B．Treating their diseases successfully. |
| C．Having them keep up with supercomputers. |
| D．Helping them to move again. |
| A．Normal. | B．Active. | C．Nervous. | D．Intelligent. |
| A．it has been a great success. |
| B．it will succeed very soon. |
| C．it has a long way to go. |
| D．It needs support from new theories. |
| A．There Will Be Great Progress in Brain Science. |
| B．Musk Shows Technology Linking Computer to Brain. |
| C．Three Pigs Are being Tested Instead of Human Beings. |
| D．The Disabled Will Receive Better Treatment in the future. |
