Curtin University research has found a simple and affordable method to determine which chemicals and types of metals are best used to store and supply energy, in a breakthrough for any battery-run devices and technologies relying on the fast and reliable supply of electricity, including smart phones and tablets.
Lead author Associate Professor Simone Ciampi from Curtin's School of Molecular and Life Sciences said this easy, low-cost method of determining how to produce and keep the highest energy charge in a capacitor (电容器) could be of great benefit to all scientists, engineers and start-ups looking to solving the energy storage challenges of the future.
"All electronic devices require an energy source. While a battery needs to be recharged over time, a capacitor can be charged instantly because it stores energy by separating charged ions (离子), found in ionic liquids, " Ciampi said.
There are thousands of types of ionic liquids, a type of "liquid salt", and until now, it was difficult to know which would be best suited for use in a capacitor. What our team has done is designing a quick and easy test, able to be performed in a basic lab, which can measure both the ability to store charge when a solid electrode touches a given ionic liquid—a simple capacitor—as well as the stability of the device when charged.
"The simplicity this test means anyone can apply it without the need for expensive equipment. Using this method, researchers found that charging the device for 60 seconds produced a full charge, which did not ‘leak' (渗漏) and begin to diminish for at least four days, " Mr Belotti said.
The next step is to use this new screening method to find ionic liquid with an even longer duration in the charged state and larger energy density.
When a chunk of ice fell from a collapsing glacier(冰川)on the Swiss Alps' Mount Eiger in 2017, part of the long deep sound it produced was too low for human ears to detect. But these vibrations held a key to calculating the ice avalanche's(崩塌)critical characteristics.
Low-frequency sound waves called infrasound that travel great distances through the atmosphere are already used to monitor active volcanoes from afar. Now some researchers in this field have switched focus from fire to ice: dangerous blocks snapping off glaciers. Previous work has analyzed infrasound from snow avalanches but never ice, says Boise State University geophysicist Jeffrey Johnson. "This was different," Johnson says. "A signature of a new material has been detected with infrasound."
Usually glaciers move far too slowly to generate an infrasound signal, which researchers pick up using detectors that track slight changes in air pressure. But a collapse—a sudden, rapid breaking of ice from the glacier's main body—is a prolific infrasound producer. Glacial collapses drive ice avalanches, which pose an increasing threat to people in mountainous regions as rising temperatures weaken large fields of ice. A glacier "can become detached from the ground due to melting, causing bigger break— offs," says University of Florence geologist Emanuele Marchetti, lead author of the new study. As the threat grows, scientists seek new ways to monitor and detect such collapses.
Researchers often use radar to track ice avalanches, which is precise but expensive and can monitor only one specific location and neighboring avalanche paths. Infrasound, Marchetti says, is cheaper and can detect break—off events around a much broader area as well as multiple avalanches across a mountain. It is challenging, however, to separate a signal into its components (such as traffic noises, individual avalanches and nearby earthquakes) without additional measurements, says ETH Zurich glaciologist Malgorzata Chmiel. "The model used by Marchetti is a first approximation for this," she says. Isolating the relevant signal helps the researchers monitor an ice avalanche's speed, path and volume from afar using infrasound.
Marchetti and his colleagues are now working to improve their detectors to pick up more signals across at-risk regions in Europe, and they have set up collaborations around the continent to better understand signals that collapsing glaciers produce. They are also refining their mathematical analysis to figure out each ice cascade's physical details.
Hoping to live on the moon one day? Your chances just got a tiny bit better. Researchers found that lunar pits and caves reach stable temperatures, making them potentially suitable for human life.
Planetary scientists at the University of California, Los Angeles have been doing the research. Although much of the moon's surface temperatures ranges from as high as 260 degrees during the day to as low as 280 degrees below zero at night, the moon has pits and caves where temperatures stay at roughly 63 degrees Fahrenheit, making human habitation a possibility, according to their new research.
For perspective, a day or night on the moon equals a little over two weeks on the earth—making long-term research and habitation difficult with such extremely hot and cold temperatures. Researchers say these stable spots could transform the future of lunar exploration and long-term habitation. The shadowed areas of these pits could also offer protection from harmful elements, such as solar radiation, universal rays and micrometeorites (微小陨石).
About 16 of the over 200 discovered pits most likely come from collapsed lava tubes—tunnels that form from cooled lava or crust, according to Tyler Horvath, a UCLA doctoral student and head of the research. The researchers think overhangs inside of these lunar pits, which were initially discovered in 2009, could be the reason for the stable temperature.
The research team also includes UCLA professor of planetary science David Paige and Paul Hayne at the University of Colorado Boulder. "Humans evolved living in caves, and to caves we might return when we live on the moon," said Paige in a UCLA press release.
There are still plenty of other challenges to establishing any sort of long-term human residence on the moon—including growing food and providing enough oxygen. The researchers made clear that NASA has no immediate plans to establish a base camp or habitations there.
A new study combining linguistic, genetic and archaeological evidence has traced the origins of the family of languages including modern Japanese, Korean, Turkish and Mongolian and the people who speak them to millet (粟) farmers who inhabited a region in northeastern China about 9, 000 years ago.
The findings detailed on Wednesday document a shared genetic ancestry for the hundreds of millions of people who speak what the researchers call Transeurasian languages across an area stretching more than 8, 000 kilometers.
The findings illustrate how humankind's embrace of agriculture following the Ice Age powered the movements of some of the world's major language families. Millet was an important early crop as hunter-gatherers transitioned to an agricultural lifestyle.
There are 98 Transeurasian languages. This language family's beginnings were traced to millet farmers in the Liao River valley, an area including parts of the Chinese provinces of Liaoning and Jilin and the region of Inner Mongolia. As these farmers moved across northeastern Asia, the descendant languages spread north and west into Siberia and east into Korea and over the sea to Japan over thousands of years.
The research stressed the complex beginnings for modern populations and cultures.
"Accepting that the roots of one's language, culture or people lie beyond the present national boundaries is a kind of surrender of identity, which some people are not yet prepared to make," said comparative linguist Martine Robbeets, lead author of the study published in the journal Nature.
"Powerful nations such as Japan, Korea and China are often pictured as representing one language, one culture and one genetic profile. But a truth is that all languages, cultures and humans, including those in Asia, are mixed," Robbeets added.
The origins of modem Chinese languages arose independently, though in a similar fashion, with millet also involved. While the ancestors of the Transeurasian languages grew millet in the Liao River valley, the originators of the Sino-Tibetan language family farmed millet at roughly the same time in China's Yellow River region, paving the way for a separate language expansion.
A "secretive" new species of frog has been discovered on the forest floor in India's Western Ghat mountain range. Named the starry dwarf frog after the markings on its dark brown back, it is just 2 centimeters long.
The frog, whose closest relatives are a group of species native to India and Sri Linka, is the only member of an ancient lineage (血统) dating back to millions of years ago, according to researchers from India and the US. It is unclear whether the species is descended from African or Asian frogs.
A group of Indian and US researchers first came across the local species hidden in leaf-litter as part of a wider project to look for new frogs, lizards and snakes in the richly biodiverse region and stored it in a jar for later study. Genetic testing and a closer look at its shape, colouring and other features has shown that it doesn't match any existing species.
Kartik Shanker of the Indian Institute of Science, who helped design the study, says while it is common to find new frogs in India, this one needs to be noticed. "This particular species not just is a new species, but also belongs to a new genus (属), and that makes it a little more special, " says Shanker.
The number of known species of frog identified in India has climbed from around 200 to above 400 over the past two decades. While many species new to science are frequently immediately sorted as endangered, it is too early to say whether the starry dwarf frog is threatened. "They are very secretive," says Shanker, adding that the team didn't know the size of its population. The frog is active at night and lives near water.
Habitat loss is a serious risk to frogs in tropical forests around the world, alongside threats such as a deadly fungus (真菌) that has been killing off amphibians (两栖动物) for the past four decades. But the new species was found in a reserved forest, meaning it will enjoy a degree of protection by Indian government agencies.
Every fall, like clockwork, Linda Krentz of Beaverton, Oregon, felt her brain go on strike. "I just couldn't get going in the morning," she says. "I'd get depressed and gain 10 pounds every winter and lose them again in the spring." Then she read about seasonal affective disorder, a form of depression that occurs in fall and winter, and she saw the light literally. Every morning now she turns on a specially constructed light box for half an hour and sits in front of it to trick her brain into thinking it's still enjoying those long summer days. It seems to work.
Krentz is not alone. Scientists estimate that 10 million Americans suffer from seasonal depression and 25 million more develop milder versions. But there's never been definitive proof that treatment with very bright lights makes a difference. After all, it's hard to do a double-blind test when the subjects can see for themselves whether or not the light is on. That's why nobody has ever separated the real effects of light therapy from placebo (安慰剂) effects.
Until now, in three separate studies published last month, researchers report not only that light therapy works better than a placebo but that treatment is usually more effective in the early morning than in the evening. In two of the groups, the placebo problem was resolved by telling patients they were comparing light boxes to a new anti-depressant device that gives off negatively charged ions (离子). The third used the timing of light therapy as the control.
Why does light therapy work? No one really knows. "Our research suggests it has something to do with shifting the body's internal clock," says psychiatrist Dr. Lewey. The body is programmed to start the day with sunrise, he explains, and this gets later as the days get shorter. But why such subtle shifts make some people depressed and not others is a mystery.
That hasn't stopped thousands of winter depressives from trying to heal themselves. Light boxes for that purpose are available without a doctor's prescription. That bothers psychologist Michael Terman of Columbia University. He is worried that the boxes may be tried by patients who suffer from mental illness that can't be treated with light. Terman has developed a questionnaire to help determine whether expert care is needed.
In any event, you should choose a reputable manufacturer. Whatever product you use should give off only visible light, because ultraviolet light damages the eyes. If you are photosensitive (对光敏感的), you may develop a rash. Otherwise, the main drawback is having to sit in front of the light for 30 to 60 minutes in the morning. That's an inconvenience many winter depressives can live with.
White was one of the first colors used in art in the 15th century, and one would think that there is little room left to improve its"whiteness". It turns out that is far from the case. A team of researchers led by Xiulin Ruan, a professor at Purdue University, recently revealed an"ultra-white"paint that they believe could even help fight climate change.
The scientists, who spent six years creating the world's "whites white"paint,
claim that the white paints currently available make surfaces warmer rather than cooler. That's because they only reflect 80 to 90 percent of the sunlight and cannot make surfaces cooler than the surrounding temperature. The newly-revealed ultra-white paint not only reflects 98. 1 percent of sunlight, but also prevents surface infrared（红外线的）heat from being absorbed.
"Our paint absorbs 1. 9% of sunlight, but those commercial paints absorb 10% of the sunlight --five times as much as our paint absorbs, "Dr. Ruan says. "They look white, they are pretty white, but they aren't white enough — they're not able to cool beyond the surrounding temperature. "
Outdoor tests of the new paint indicated it could keep surfaces 5℃ cooler than the surrounding temperature under the strong noon sunlight and as much as 10℃ cooler at night.
"We did a very rough calculation, "Dr. Ruan told a news reporter. "And we estimate we would only need to paint 1 percent of the Earth's surface with this paint-perhaps an area where no people live that is covered in rocks --and that could help fight the climate change trend. "
However, Hashem Akbari, professor of building at Concordia University, believes the paint's real benefits can only be proved after being in use for a few years. "Dirt and dust tend to decrease the reflectivity of the surface, "Akbari said. "If it starts with 95% reflectivity, the pollutants from the air could collect on the surface, and they decrease the reflectivity.
Picture an iceberg（冰山）. You'll probably imagine something white as snow rising up out of a blue sea. But icebergs can be all sorts of shades. They can be from a frosty blue to an attractive green.
Researchers and sailors have observed emerald（翠绿色）icebergs for years. A large piece of ice"mast-high"and"green as emerald"even appears in Samuel Taylor Coleridge's 1834 poem. But they haven't found out exactly why these icebergs look the way they do.
A new paper led by Stephen Warren was published. It all has to do with what icebergs are made out of. Icebergs break off glaciers（冰川）or ice shelves, which happens mainly around Antarctica and Greenland. They begin their lives as snowfall that accumulates over time. So icebergs contain air pockets with the form of bubbles that spread light. With some exceptions and rare lines, glacier ice tends to look bluish white.
At first, Warren guessed that the green was a product of melt carbon. And it came from rotting plants or sea animals. But samples（样本）didn't prove it. Another idea started to take shape after they had found a high concentration of iron in a sample of sea ice from the Amery Ice Shelf.
When glaciers rub across land, they produce what's known as glacier flour. It is a product of bedrock being ground clown by the moving mass. As glaciers move away, these remains are usually washed out into water, in particles（颗粒） sometimes too small to be noticeable to your eyes. But on land, soil and rocks contain iron oxides（氧化铁）that often have rosy colors, like reds, yellows, and browns—and since the sea ice contained 500 times more iron than the glacier ice, Warren wondered whether the remains were responsible for icebergs taking on a green appearance.
He doesn't know for sure. He's hoping to secure money so that he can return to the area and study the icebergs themselves.
Many sensing systems used in water have a problem: They rely on batteries that are often made from unsustainable materials, so such batteries will need replacing at some point.
To look for a cleaner, more long-lasting alternative, Zhonglin Wang at the Chinese Academy of Sciences，Beijing，and his colleagues have created a self-charging buoy (浮标). It uses nanogenerators (纳米发电机) to gain power from the movement of waves.
The buoy consists of an acrylic (丙烯酸的) ball about 10 centimeters across and four nanogenerators connected to a part that collects the produced charge. As the water moves back and forth through the nanogenerators, they generate around 24.5 milliwatts of power.
It is suggested that the buoy could be used to check and monitor water levels for early flood warning systems. However, there are already many effective and cheap alternatives for this task, says Wouter Buytaert at Imperial College London. Non-contact methods, such as lidar (激光雷达), are probably more suitable for sensing water levels， he explains.
"The new power generation method could prove useful for situations in which non-contact methods aren't workable, though, such as water quality sensing," Buytaert says. "There have been devices similar to the buoys in measuring and checking long-term water quality. But if such application is combined with the function of power collecting shown here, it could be more promising, "Buytaert says.
However, if used in rivers, the buoy would possibly be damaged by rising or violently moving water, especially if they are fixed at the rapids of the flood as an early warning system. "In these environments, there is often a high sand load in the river during a flood, so any sensor actually in the river is likely to get destroyed, "says Liz Stephens at the University of Reading, UK.
To address the plastic pollution troubling the world's seas and waterways, Cornell University chemists have developed a new polymer (聚合物) that can degrade (降解) plastic when exposed to ultraviolet radiation, according to the research published in the Journal of the American Chemical Society.
"We have created a new plastic that has the mechanical properties required by commercial fishing gear. If it eventually gets lost in the water environment, this material can degrade on a realistic time scale," said lead researcher Bryce Lipinski, professor of chemistry and chemical biology at Cornell University. "This material could effectively reduce persistent plastic accumulation in the environment."
Commercial fishing contributes to about half of all floating plastic waste that ends up in the oceans. Fishing nets and ropes are primarily made from three kinds of polymers, none of which easily degrade. "While research of degradable plastics has received much attention in recent years," Lipinski said, "obtaining a material with a mechanical strength comparable to commercial plastic remains a difficult challenge."
Coates and his research team have spent the past 15 years developing the new plastic called isotactic polypropylene oxide, or iPPO. While its original discovery was in 1949, the mechanical strength of this material was unknown before this recent work. The high isotacticity and polymer chain length of their material makes it different from previous plastics and provides its mechanical strength.
Lipinski and other scientists want no race of the polymer to be left in the environment. He notes there is precedent (先例) for the biodegradation of small chains of iPPO which could effectively make it disappear and ongoing efforts aim to prove this.
