EurekAlert July 7, 2021 Researchers in Ireland have developed a technique that would enable the future production of entirely renewable, clean energy from which water would be the only waste product. They used an automated combinatorial approach and advanced quantum chemical modelling and found nine earth-abundant combinations of metals and ligands as highly promising leads for experimental investigation. They found chromium, manganese, iron to be especially promising. Thousands of catalysts based around these key components can now be placed in a melting pot and assessed for their abilities as the hunt for the magic combination continues. They have screened 444 and […]
Graphene additive manufacturing for flexible and printable electronics
Phys.org July 2, 2021 As a proof-of-concept researchers at Kansas State University used graphene aerosol gel ink, synthesized via an energy efficient, catalyst-free, and nonhazardous chemical precursor detonation method, such as hydrocarbons (e.g., acetylene) in the presence of controlled oxygen. They used the ink to print microsupercapacitors in interdigitated electrodes (IDEs) geometry on 25-μm thick polyimide substrates using a micro plotter. The microsupercapacitors showed an aerial capacitance of 55 μF/cm2 and volumetric capacitance of 3.25 F/cm3 at a current density of 6.0 microamp/cm2 and 20 milliamp/cm3, respectively. The printed devices did not show a significant distortion in the cyclic voltammetry […]
Has the stilling of surface wind speed ended in China?
Phys.org June 28, 2021 Since the 1960s, the global land surface wind speed (SWS) has significantly weakened, a phenomenon known as global terrestrial stilling. The stilling reversed around 2010 and global SWS is strengthening. It has seriously affected the ecological environment and social economy, especially restricting the sustainable development of the wind energy industry. Researchers in China analyzed the transition and regional differences in the long-term trends of the SWS in China based on observational SWS data from 1971 to 2019. The results showed that annual mean SWS in China underwent a reversal from a continuous weakening trend to a […]
Insect-sized robot navigates mazes with the agility of a cheetah
Science Daily July 2, 2021 Researchers in Japan used a curved piezoelectric thin film driven at its structural resonant frequency as the main body of an insect-scale soft robot for its fast translational movements, and two electrostatic footpads were used for its swift rotational motions. These two schemes were simultaneously executed during operations through a simple two-wire connection arrangement. They achieved a high relative centripetal acceleration of 28 body length per square second which is better than those of common insects, including the cockroach. In demonstration the robot passed through a 120-centimeter-long track in a maze within 5.6 seconds. The […]
Method uses radio signals to image hidden and speeding objects
Phys.org June 25, 2021 Light-in-flight sensing has emerged as a promising technique in image reconstruction applications at various wavelengths. A team of researchers in the US (NIST, industry, University of Colorado) has developed a microwave imaging system that uses an array of transmitters and a single receiver operating in continuous transmit-receive mode. Captures take a few microseconds, and the corresponding images cover a spatial range of tens of square meters with spatial resolution of 0.1 meter. The images are the result of a dot product between a reconstruction matrix and the captured signal with no prior knowledge of the scene. […]
New type of metasurface allows unprecedented laser control
Phys.org June 29, 2021 An international team of researchers (USA – Harvard University, Italy) has developed a tunable laser that has two components—a laser diode and a reflective metasurface. The metasurface surface uses supercells, groups of pillars which work together to control different aspects of light. It is designed so that only the selected wavelength has the correct direction to enter back in the diode enabling the laser to operate only at that specific wavelength. The wavelength can be changed by moving the metasurface with respect to the laser diode. The shape of the laser beam can be fully controlled […]
The pressure is off and high temperature superconductivity remains
Phys.org July 8, 2021 The grand challenge in superconductivity research and development is no longer restricted to further increasing the superconducting transition temperature under extreme conditions and must now include concentrated efforts to lower, and better yet remove, the applied pressure required. An international team of researchers (USA – Houston University, Rice University, China) has shown such a possibility in the pure and doped high-temperature superconductor FeSe by retaining, at ambient pressure via pressure quenching, its Tc up to 37 K and other pressure-induced phases. They observed that some phases remain stable without pressure at up to 300 K and […]
Quantum laser turns energy loss into gain
Phys.org July 7, 2021 Parity-time reversal symmetry in non-Hermitian systems realizes spontaneous symmetry breaking. A team of researchers in South Korea have demonstrated that such direct coupling can remodel conventional photonic platforms of non-Hermitian systems into polaritonic platforms with a single component; thus, improving the degrees of freedom of both integration and design for the coupled system. In this system, they found that as energy loss increased, the amount of energy needed to induce lasing decreased. By controlling the degree of loss between the microcavity and the semiconductor substrate the threshold energy becomes smaller as energy loss increases. According to […]
Researchers discover unusual competition between charge density wave and superconductivity
Phys.org July 5, 2021 To study the layered cage structure superconductor CsV3Sb5, which has a charge density wave (CDW) transition temperature of 94 K, researchers in China conducted high-pressure electrical transport and magnetic susceptibility measurements. They found that the CDW transition is monotonically suppressed by pressure, and superconductivity is enhanced with increasing pressure up to P1 ≈ 0.7 GPa. They found an unexpected suppression of superconductivity until pressure around 1.1 GPa, after that, Tc was enhanced with increasing pressure again. The CDW was completely suppressed at a critical pressure P2 ≈ 2 GPa together with a maximum Tc of about 8 K. The pressure-dependent Tc showed an unexpected […]
Researchers identify ultrastable single atom magnet
Phys.org July 7, 2021 An international team of researchers (South Korea, Germany) has shown that dysprosium (Dy) atoms on magnesium oxide (MgO) have a giant (magnet/ic anisotropy energy) MAE of 250 meV, currently the highest among all surface spins. Using a variety of scanning tunnelling microscopy (STM) techniques including single atom electron spin resonance (ESR), they confirmed that there was no spontaneous spin-switching in Dy over days at ≈ 1 K under low and even vanishing magnetic field. They utilized these robust Dy single atom magnets to engineer magnetic nanostructures, demonstrating unique control of magnetic fields with atomic scale tunability. The work […]