For more than 25 years, the Advanced Photon Source's intense X-rays have enabled important breakthroughs. With a massive upgrade in the works, scientists will be able to see things at scale never seen before.
A different kind of design for absorbing vibrations could help better soundproof walls and make vehicles more streamlined, a new study shows.
Millimeter wave (mmWave) communications have attracted extensive interest from academia, industry, and government as they can make full use of abundant frequency resources at the high-frequency band to achieve ultra-high-speed data transmission. The mmWave communication systems are usually equipped with large antenna arrays, known as mmWave massive multiple-input multiple-output (MIMO), to generate highly directional beams and compensate for the severe path loss in the high frequency band. However, the performance of directional beamforming largely relies on the accuracy of channel state information (CSI) acquisition. Compared to the traditional MIMO systems, the CSI acquisition in mmWave massive MIMO systems is challenging. On one hand, the large antenna arrays form a high dimension channel matrix, whose estimation consumes more resources, e.g., pilot sequence overhead, sounding beam overhead, and computational complexity. On the other hand, the mmWave massive MIMO typically employs a hybrid beamforming architecture, where the radio frequency (RF) chains are much fewer than the antennas. Therefore, we can only obtain a low-dimension signal from the RF chains instead of directly getting a high-dimension signal from the frontend antennas, which makes CSI acquisition much more challenging than usual.
In efforts to fight obesity and enhance drug absorption, scientists have extensively studied how gastric juices in the stomach break down ingested food and other substances. However, less is known about how the complex flow patterns and mechanical stresses produced in the stomach contribute to digestion.
In a finding that will give theorists plenty to ponder, an all-RIKEN team has observed an unexpected response in an exotic material known as a Mott insulator when they injected electrons into it. This observation promises to give physicists new insights into such materials, which are closely related to high-temperature superconductors.
Quantum information could be behind the next technological revolution. By analogy with the bit in classical computing, the qubit is the basic element of quantum computing. However, demonstrating the existence of this information storage unit and using it remains complex, and hence limited. In a study published on 3 August 2021 in Physical Review X, an international research team consisting of CNRS researcher Fabio Pistolesi1 and two foreign researchers used theoretical calculations to show that it is possible to realize a new type of qubit, in which information is stored in the oscillation amplitude of a carbon nanotube.
Two physicists, from EPFL and Columbia University, have introduced an approach for simulating the quantum approximate optimization algorithm using a traditional computer. Instead of running the algorithm on advanced quantum processors, the new approach uses a classical machine-learning algorithm that closely mimics the behavior of near-term quantum computers.
Rocket engines contain confined combustion systems, which are essentially combustion chambers. In these chambers, nonlinear interactions among turbulent fuel and oxidizer flows, sound waves, and heat produced from chemical reactions cause an unstable phenomenon called "combustion oscillations." The force of these oscillations on the body of the combustion chamber—the mechanical stress on the chamber— is high enough to threaten catastrophic failure of the engine. What causes these oscillations? The answer remains to be found.
Occurring faster than the speed of sound, the mystery behind the breakdown of plasma discharges in water is one step closer to being understood as researchers pursue applying new diagnostic processes using state-of-the-art X-ray imaging to the challenging subject.
"Many of the greatest challenges of our time, from clean energy to environmental justice, require new approaches to the craft of scientific experimentation. This is exceedingly apparent in the field of electron microscopy. As researchers utilize this powerful window to peer into the atomic machinery behind today's technologies, they are increasingly inundated with data and constrained by traditional operating models. We must leverage artificial intelligence and machine learning in our scientific instruments if we are to unlock breakthrough discoveries."
Researchers from the University of Turku have discovered a new method of X-ray imaging based on the coloring abilities of the natural mineral hackmanite. The international group of researchers also found out how and why hackmanite changes color upon exposure to X-rays.
Digital transistors—assembled by the billions in today's computer chips—act as near-perfect electronic switches. In the "on" position, achieved when an above-threshold voltage is applied to the device, the transistor allows current to flow. When the switch is off, the transistor prevents the flow of current. The on/off positions of the switch translate into the 1s and 0s of digital computation.
Dark matter remains one of the greatest mysteries in science. Despite decades of astronomical evidence for its existence, no one has yet been able to find any sign of it closer to home. There have been dozens of efforts to do so, and one of the most prominent just hit a milestone—the release and analysis of eight years of data. The IceCube Neutrino Observatory will soon be releasing results from those eight years, but for now let's dive in to what exactly they are looking for.
Electrical engineers from the UCLA Samueli School of Engineering have developed a more efficient way of converting light from one wavelength to another, opening the door for improvements in the performance of imaging, sensing and communication systems.
Magnetizing a material without applying an external magnetic field is proposed by researchers at São Paulo State University (UNESP), Brazil, in an article published in the journal Scientific Reports, where they detail the experimental approach used to achieve this goal.
An international team from Delft, Lancaster, Nijmegen, Kiev and Salerno has demonstrated a new technique to generate magnetic waves that propagate through the material at a speed much faster than the speed of sound.
A team of scientists has developed a means to create a new type of memory, marking a notable breakthrough in the increasingly sophisticated field of artificial intelligence.
Machine learning, a form of artificial intelligence, vastly speeds up computational tasks and enables new technology in areas as broad as speech and image recognition, self-driving cars, stock market trading and medical diagnosis.
Scientists studying particle collisions at the Relativistic Heavy Ion Collider (RHIC)—a U.S. Department of Energy Office of Science user facility for nuclear physics research at DOE's Brookhaven National Laboratory—have produced definitive evidence for two physics phenomena predicted more than 80 years ago. The results were derived from a detailed analysis of more than 6,000 pairs of electrons and positrons produced in glancing particle collisions at RHIC and are published in Physical Review Letters.
Researchers at the University of Sydney and quantum control startup Q-CTRL today announced a way to identify sources of error in quantum computers through machine learning, providing hardware developers the ability to pinpoint performance degradation with unprecedented accuracy and accelerate paths to useful quantum computers.
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