Phys.org November 10, 2021 Researchers in China developed a highly efficient magneto-tunable and phonon-based monochromatic THz generator with a frequency of ~0.9 THz using a 2D ferromagnetic Cr2Ge2Te6 crystal. They combined theoretical and experimental approaches and innovatively exploited the excellent properties of its van der Waals interlayered breathing phonon mode (boson) with THz-TDS (time domain spectroscopy) magneto-optic system. They found the breathing mode could effectively couple with incident co-frequency THz pulse and form a phonon-polariton. This quasi-bosonic particle could then generate far-field electro-magnetic radiation with monochromatic frequency comparable to the phonon mode. They regulated the radiation via the spin-phonon interaction […]
Nuclear radiation used to transmit digital data wireless
Phys.org November 10, 2021 An international team of researchers (UK, Slovenia) reports on the configuration and operation of a nuclear instrumentation set-up designed to transmit digitally encoded information using fast neutrons. They measured the spontaneous emission of fast neutrons from californium-252, a radioactive isotope produced in nuclear reactors. Modulated emissions were measured using a detector and recorded. A word, the alphabet and a random number selected blindly, were encoded serially into the modulation of the neutron field and the output decoded on a laptop which recovered the encoded information on screen. A double-blind test was performed in which a number […]
Storing energy in plants with electronic roots
Science Daily November 8, 2021 By watering bean plants with a solution that contains conjugated oligomers an international team of researchers (Sweden, France, Spain, Greece) has shown that the roots of the plant become electrically conducting and can store energy. To circumvent biological barriers encountered in previous attempts, and access the internal tissue, the researchers leveraged the biocatalytic machinery of the plant cell wall to seamlessly integrate conductors with mixed ionic–electronic conductivity along the root system of the plants. They used a trimer, ETE-S, which is polymerized by a natural process in the plant. The roots remained electrically conducting for […]
Student’s research upends understanding of upper atmospheric wind
Phys.org November 10, 2021 Researchers at the University of Alaska analyzed ground-based remote sensing measurements of thermospheric neutral winds above Alaska, at 240 km altitude to study how space weather affects the well-known large-scale flow that carries winds from the sunlit dayside of the Earth across the polar cap into the night side. This flow feature is typically expected to emerge from the polar cap in the midnight sector and continue blowing equatorward well into sub-auroral latitudes. However, their data showed instances in which the equatorward flow instead stalls over Alaska in an unexpectedly abrupt manner. They found this most […]
Ultra-thin crystals as light sources in lasers
Nanowerk November 8, 2021 Previously an international team of researchers (Germany, Russia, USA – Arizona State University, Japan) reported that a layer of the semiconductor material molybdenum diselenide generated laser light at cryogenic temperatures. Now they created the same effect at room temperature in exciton-polaritons. If sufficient exciton-polaritons are generated, they merge into a macroscopic quantum state. A sudden increase in light emission from the sample indicates that this transformation has taken place. The resulting radiation has only a single wavelength and displays coherence. To demonstrate the effect, they placed thin layers of tungsten diselenide between special mirrors. By studying the […]
Unnerving Study Reveals There May Be No Warning For The Next Supervolcano Eruption
Science Alert November 6, 2021 An international team of researchers (China, Taiwan, Switzerland, Malaysia, Indonesia) conducted a a detailed study of the Toba volcano in Sumatra, Indonesia analyzing the chemistry of zircons minerals produced by explosive volcanic eruptions to determine the age of the minerals. Their findings suggest that the gigantic eruptions from Toba some 840,000 years ago and 75,000 years ago were not preceded by a sudden influx of magma into the volcano’s reservoir. Instead, the magma collected steadily and silently ahead of the blasts. The second super-eruption needed less than half the time for magma to build up than […]
Weather balloon data shows troposphere getting thicker, pushing tropopause higher over past 40 years
Phys.org November 8, 2021 Tropopause height (H) is a sensitive diagnostic for anthropogenic climate change. Previous studies showed increases in H over 1980–2000 but were inconsistent in projecting H trends after 2000. While H generally responds to temperature changes in the troposphere and stratosphere, the relative importance of these two contributions is uncertain. An international team of researchers (China, Canada, USA – NCAR, Boulder CO, Austria) used radiosonde balloon observations in the Northern Hemisphere (NH) over 20°N to 80°N to reveal a continuous rise of H over 1980–2020. Over 2001–2020, H increases at 50 to 60 m/decade, which is comparable […]
Top 10 Science and Technology Inventions for the Week of November 5, 2021
01. Creating an artificial material that can sense, adapt to its environment 02. This device could usher in GPS-free navigation 03. Diffractive optical networks reconstruct holograms instantaneously without a digital computer 04. Engineers invent ultra-fast manufacturing technology 05. A new dimension in magnetism and superconductivity launched 06. A proactive approach to removing space junk 07. Researchers develop a tool to neutralize chemical weapons using rare-earth elements 08. Towards straintronics: Guiding excitons in 2D materials 09. Trapping spins with sound 10. Towards self-restoring electronic devices with long DNA molecules And others… Better hurricane forecasts from use of infrared satellite measurements of […]
Better hurricane forecasts from use of infrared satellite measurements of cloudy skies
Phys.org November 4, 2021 An international team of researchers (USA – University of Wisconsin, NCAR Boulder, UK, Japan, China) surveyed the best practices for the observation and use of satellite infrared sounder and imager measurements demonstrating significant improvement in the forecasting of high-impact weather events such as hurricanes and typhoons. They reviewed development of satellite infrared data assimilation by various practitioners and the solutions they have deployed to better use such data in forecasts. They found that use of these cloud-cleared radiances in data assimilation improves the forecasting of high-impact weather events such as tropical cyclones and is now being applied […]
Better models of atmospheric ‘detergent’ can help predict climate change
Phys.org November 1, 2021 The hydroxyl radical (OH) sets the oxidative capacity of the atmosphere and thus, profoundly affects the removal rate of pollutants and reactive greenhouse gases. OH estimates for past and future periods rely primarily on global atmospheric chemistry models. The models disagree ± 30% in mean OH and in its changes from the preindustrial to late 21st century. A simple steady-state relationship that accounts for ozone photolysis frequencies, water vapor, and the ratio of reactive nitrogen to carbon emissions explains temporal variability within most models, but not intermodal differences. A team of researchers in the US (University […]