Inspired by the ancient Chinese bronze mirror technique, scientists used liquid crystals to create flat "magic windows"
The researchers used liquid crystals to create magic windows that produce hidden images when light shines on them.
For the first time, Canadian researchers have used liquid crystals to create a flat magic window, a transparent device that produces hidden images when light is illuminated. In the latest issue of the journal Optics, the researchers describe the process of creating this liquid crystal magic window that can produce any desired image. The process can also be used to create "magic mirrors" that are based on reflection rather than transmitted light.
Thousands of years ago, Chinese craftsmen made a bronze mirror that looks like an ordinary flat mirror when viewing their own image, but forms another image when the sun is shining. It wasn't until the early 20th century that scientists understood how these devices worked because images projected onto the back of mirrors produced tiny surface changes that led to image formation.
Felix Hufunai gill, head of the research team at the University of Ottawa, said: "The magic window we created is completely flat to the naked eye, but in fact there are slight variations that produce images based on light. By designing the window to be relatively smooth, you can see the created image at a distance from the window. ”
Researchers say that the use of liquid crystals to make magic windows or magic mirrors could one day be used to make dynamic art magic windows or movies. This method can also be adapted to 3D displays, so that stable 3D images can also be produced when viewed from different distances.
Liquid crystals are materials that can flow like traditional liquids but have molecules that are oriented like solid crystals. The researchers have improved on a well-known manufacturing process that produces a specific liquid crystal pattern that produces the desired image when irradiated.
They used Pancharatnem-Berry (PB) optics, a liquid crystal device that operates on the PB phase principle. By changing the orientation of the liquid crystal molecules in the device, the researchers could change the characteristics of light as it passes through the device pixel by pixel.
After making the magic mirror and the magic window, the researchers used the camera to measure the light intensity patterns produced by the two devices. When illuminated with a laser beam, both the mirror and the window produce a visible image that remains stable even if the distance between the camera and the mirror or window changes. Research also shows that these devices also produce images when illuminated with LED light sources, which is more practical to use in real life.
Researchers are currently using the method to make quantum magic plates, for example, two of which can create entangled images to study quantum imaging protocols. They are also exploring the possibility of using methods other than liquid crystals to create magic windows, such as the use of dielectric metasurfaces to make magic window devices that reduce their footprint while increasing bandwidth.
(Source: Science and Technology Daily)
How did dinosaurs change their teeth? Paleontologists demystify the ancient horned dragon's way of changing teeth
Mammals (including humans) only change their teeth once in a lifetime. Hundreds of millions of years ago, how did dinosaurs change their teeth? The reporter learned from China University of Geosciences (Wuhan) that the research team of Associate Professor Han Fenglu of the School of Earth Sciences of the university joined hands with Chinese and foreign researchers to study the tooth morphology and replacement characteristics of early horned dragons, and revealed the teeth replacement methods of early horned dragons. The relevant research results have recently been published online in the international biological journal Electronic Life.
Triceratops, which lived in the late Cretaceous period, was famous for its peculiar shape, with up to 800 teeth in its mouth. Their teeth are replaced for life and have a very fast replacement rate, taking only about 3 months to change their teeth once. However, the ancestral taxa of Triceratops lacked this complex dental system.
Han Fenglu told reporters that in order to study the tooth replacement of early horned dragons, researchers performed microscopic CT scans of the skulls and teeth of three early horned dragons that mainly lived in the Jurassic Period, and observed the development of functional teeth and replacement teeth by reconstructing the 3D model of teeth.
The researchers found that early horned dragons had very different dental features from triceratops: early horned dragons had a very small number of replacement teeth, indicating that early horned dragons had much slower teeth changes than those that appeared later. The new teeth of early horned dragons also grew in a different location than those of Triceratops, with new teeth growing from the base of older teeth, while new teeth of early horned dragons grew from the inside of older teeth.
Why were the dental systems of early ceratops and Triceratops so different? Han Fenglu believes that the early horned dragon was smaller, such as the length of the Dang's hidden dragon was only about 1.2 meters, while the length of the triceratops reached about 9 meters, and the increase in body size led to the increase in the demand for food of the triceratops and higher requirements for the teeth.
"The complex tooth morphology of Triceratops allowed them to fully chew on food in the mouth, while the teeth of early ceratosaurs were simple, probably only the function of cutting plants, and the difference in function also led to differences in the dental system of the two." Han Fenglu added that gastroparagus was also found in The Hidden Dragon and another early horned dragon, Psittaculosaurus, suggesting that they most likely swallowed small stones into the stomach like modern birds to aid digestion, making the teeth bear less pressure and the wear and tear of the teeth slower.
(Source: Science and Technology Daily)
Accenture releases its 2022 Technology Outlook – four major technology trends will form a meta-universe base
Accenture recently released a report "Technology Outlook 2022" pointed out that the four major technology trends of the future network, the coding world, the symbiosis of virtual reality, and unlimited computing power will become the cornerstone of building a metaverse, and there are also a lot of opportunities that are worth tapping.
At present, more and more enterprises are beginning to invest in the research and development and commercialization of the metacosm. Jia Jin, president of Accenture Greater China Enterprise Technology Innovation Division, said that the metacosm is a synthesis of various new technologies used by humans, with rich application scenarios, many new business models will be born, and will have a subversive impact on human life in the next few years. By using technologies such as the cloud, digital twins, and edge computing, the metaverse is able to seamlessly connect different geographic locations. In addition, the metaverse will bring about changes in data ownership. In the era of digital platforms, data is often in the hands of the platform, which also hinders the cross-platform experience of users, and the metacosm will redefine data assets and data ownership because of its cross-platform nature.
The report focuses on four major technology trends. The future of the web will reconfigure the Internet, the rise of the metacosm will reshape the role of data in shaping digital experiences, and force businesses to rethink the new meaning of "online" and plan new ways to connect with customers, partners and digital work teams before the next platform revolution arrives.
The world of coding shows how technology penetrates into the physical environment in a subtle, silent way. When technologies such as 5G, environmental computing, augmented reality, and smart materials are integrated with the physical environment, companies will open up new ways of interacting with the real world, and people will control smart devices in unprecedented ways, automate and personalize settings.
Virtual-real symbiosis means that people will use more and more machines that are close to human capabilities in their living environments and business scenarios. Companies are eager to apply artificial intelligence (AI) in key production and operations, and even the data that trains the AI itself is generated by the AI.
With the advent of a new generation of computers, unlimited computing power will push the limits of computing. Quantum computers, biological computers and high-performance computers will overcome the bottlenecks in computing power that restrict the development of industries and enterprises. Jia Jin believes that computing power will be an important factor that determines the success or failure of enterprises in the meta-universe competition, and its 3 technical directions are worth paying attention to: one is the further expansion of computing power by traditional computing methods, the second is quantum computing, and the third is biological computing chips.
Jia Jin said that every change in the way of interconnection will produce new leaders. At present, the application and landing scenarios of each enterprise are different. As technology advances, a company's local attempts may become universal applications that any business and individual can join, ultimately creating a disruptive effect.
(Source: Economic Daily)
I'm super sweet! The sucrose concentration at the bottom of seagrass was approximately 80 times higher than recorded
"Super sweet" seaweed
According to a study recently published in the British journal Nature Ecology and Evolution, a team of American scientists found that the concentration of sucrose accumulation at the bottom of seagrass fields was about 80 times higher than previous ocean records. These findings suggest that seagrass may amount to a vast global reservoir of organic carbon, presumably due to inhibition of microbial activity that breaks down carbon.
Seagrasses are important marine habitats because they both provide shelter and food for marine biodiversity and may also store 35 times more carbon in plant tissues, on the same area, than terrestrial rainforests. Seagrass also secretes carbon from its roots in the form of monosaccharides and other compounds. But the role of marine microbes in the depletion and circulation of this carbon source has not yet been understood.
This time, McGee Sokin, a researcher at the University of California, Merced, and colleagues analyzed the chemical composition of water samples (also known as pore water) in the bottom sediments of three different oceanic seagrasses in the Mediterranean Sea, as well as other seagrass meadows in the Caribbean and Baltic Seas. They found unexpectedly high concentrations of sucrose near the roots of seagrass: globally, the upper 30 cm layer of seagrass sediments stored the equivalent of 0.67-1.34 tes of sucrose.
By analyzing microbes living in sediments beneath seagrass fields, the researchers found that while 80 percent of the recovered microbial genomes contained genes that broke down sucrose, these genes were expressed in only 64 percent of the genomes. They predict that a low-oxygen environment combined with phytophenols (which significantly inhibits microbial activity) may explain the accumulation of sucrose.
The team concluded that the accumulation of sucrose beneath seagrass could serve as a valuable storage method of organic carbon, and this may also be found in other marine and aquatic plants.
(Source: Science and Technology Daily)
AI algorithms enable light-speed seismic monitoring
The AI algorithm estimates a schematic diagram of the magnitude of a large earthquake based on PEGS, which travels at the speed of light and is much faster than seismic waves.
A study published in the British journal Nature on the 11th showed that a machine learning model can accurately estimate the evolution of large earthquakes in real time, and this trained machine learning model can determine the gravitational change signal propagating at the speed of light.
The monitoring of earthquakes generally requires the determination of seismic waves, which are pulses of energy propagating through the Earth's crust. However, earthquake wave-based early warning systems sometimes react too slowly to accurately estimate the magnitude of an earthquake in the event of a large earthquake (moment magnitude 8 or more). One solution is to track the instantaneous elastic gravity signal (PEGS), which travels at the speed of light and is generated by a sudden shift in gravity caused by a sudden misalignment of a rock mass. However, whether PEGS can be used to make fast and reliable real-time estimates of the orientation and development after the emergence of large earthquakes has yet to be verified.
Scientists from the University of the Côte d'Azur, the French Institute for Development Studies, the French National Centre for Scientific Research, and the Côte d'Azur Observatory simulated 350,000 seismic scenarios at 1,400 potential seismic locations in Japan and trained a deep learning model (PEGSNet) using PEGS signals. The researchers then tested the model with real-time data from the 2011 Tohoku earthquake, one of the largest and most destructive earthquakes ever recorded.
The researchers found that PEGSNet accurately calculated the azimuth of earthquakes, the size of earthquakes, and the change of earthquakes over time. Importantly, PEGSNet can quickly give this information and make a judgment before the seismic waves arrive.
The researchers conclude that PEGSNet may play an important role in the early monitoring of large earthquakes and their evolution, from surface ruptures to possible associated tsunamis. While the model is primarily aimed at Japan, they stress that it works well in other regions as well, allowing the strategy to be used in real time with minimal adjustments.
(Source: Science and Technology Daily)