Science Daily July 15, 2021 Many microorganisms exploit the fact that elasticity breaks the time-reversal symmetry of motion at low Reynolds numbers, but this principle has been notably absent from model systems of active, self-propelled micro swimmers. An international team of researchers (Bulgaria, Poland, UK) has introduced a class of micro swimmers that spontaneously self-assembles and swims without using external forces, driven instead by surface phase transitions induced by temperature variations. The swimmers are made from alkane droplets dispersed in an aqueous surfactant solution, which start to self-propel on cooling, pushed by rapidly growing thin elastic tails. When heated, the […]
Toward one drug to treat all coronaviruses
Science Daily July 21, 2021 A strategy to develop broad-spectrum inhibitors is to pharmacologically target binding sites on SARS-CoV-2 proteins that are highly conserved in other known coronaviruses, the assumption being that any selective pressure to keep a site conserved across past viruses will apply to future ones. An international team of researchers (Canada, UK) systematically mapped druggable binding pockets on the experimental structure of 15 SARS-CoV-2 proteins and analyzed their variation across 27 α- and β-coronaviruses and across thousands of SARS-CoV-2 samples from COVID-19 patients. They found that the two most conserved druggable sites are a pocket overlapping the […]
‘Wrapping’ anodes in 3D carbon nanosheets: The next big thing in li-ion battery technology
Science Daily July 22, 2021 The anodes of lithium ion batteries in use today have multiple inadequacies. Researchers in South Korea focused on manganese selenide (MnSe) for its high electrical conductivity. To prevent the drastic volume change it undergoes, they uniformly infused the MnSe nanoparticles into a three-dimensional porous carbon nanosheet matrix. In the new anode material (MnSe ⊂ 3DCNM), the carbon nanosheet scaffold provided MnSe nanoparticles with a high number of active sites and an enhanced contact area with the electrolyte and protected them from drastic volume expansion. They synthesized a variety of MnSe ⊂ 3DCNM materials. Among these, […]
Top 10 Science and Technology Inventions for the Week of July 16, 2021
01. The hidden culprit killing lithium-metal batteries from the inside 02. The next generation of information processing is through coherent gate operations 03. New evidence of an anomalous phase of matter brings energy-efficient technologies closer 04. Preventing oxygen release leads to safer high-energy-density batteries 05. Scientists develop novel DNA logic circuits 06. Scientists Have Created a New Bendy And Flexible Form of Ice 07. Cooling high power electronics – boron arsenide spreads heat better than diamond 08. Electrons in quantum liquid gain energy from laser pulses 09. Harnessing the dark side 10. New ‘Metafabric’ Passively Cools The Human Body by […]
Cooling high power electronics – boron arsenide spreads heat better than diamond
Nanowerk July 9, 2021 A team of researchers in the US (UCLA, UC Irvine) explored the interface energy transport in semiconductor materials with high thermal conductivity, including boron arsenide (BAs) and boron phosphide (BP). They showed that BAs and BP cooling substrates can be heterogeneously integrated with metals, a wide-bandgap semiconductor (gallium nitride, GaN) and high-electron-mobility transistor devices. GaN-on-BAs structures exhibit a high thermal boundary conductance of 250 MW m−2 K−1, and comparison of device-level hot-spot temperatures with length-dependent scaling (from 100 μm to 100 nm) shows that the power cooling performance of BAs exceeds that of reported diamond devices. Operating AlGaN/GaN high-electron-mobility transistors with […]
The demonstration of ultrafast switching to an insulating-like metastable state
Phys.org July 13, 2021 Superconductors host collective modes that can be manipulated with light. An international team of researchers (Japan, France) has shown that a strong terahertz light field can induce oscillations of the superconducting order parameter in NbN with twice the frequency of the terahertz field. The result can be captured as a collective precession of Anderson’s pseudospins in ac driving fields. A resonance between the field and the Higgs amplitude mode of the superconductor then results in large terahertz third-harmonic generation. Their method paves a way toward nonlinear quantum optics in superconductors with driving the pseudospins collectively and […]
Discovery of 10 faces of plasma leads to new insights in fusion and plasma science
Phys.org July 13, 2021 Researchers at Princeton University systematically mapped out all the topological phases of cold magnetized plasmas and established the bulk-edge correspondence. They found that for the linear eigenmodes, there are 10 topological phases in the parameter space of density n, magnetic field B, and parallel wavenumber kz, separated by the surfaces of Langmuir wave-L wave resonance, Langmuir wave-cyclotron wave resonance, and zero magnetic field. For fixed B and kz, only the phase transition at the Langmuir wave-cyclotron wave resonance corresponds to edge modes. A sufficient and necessary condition for the existence of this type of edge modes […]
Electrons in quantum liquid gain energy from laser pulses
Phys.org July 13, 2021 Laser-assisted electron scattering (LAES), a light–matter interaction process that facilitates energy transfer between strong light fields and free electrons, has so far been observed only in gas phase. An international team of researchers (Austria, Japan) has detected LAES at condensed phase particle densities, for which they created nano-structured systems consisting of a single atom or molecule surrounded by a superfluid He shell of variable thickness. They observed that free electrons, generated by femtosecond strong-field ionization of the core particle, can gain several tens of photon energies due to multiple LAES processes within the liquid He shell. […]
Global evidence links rise in extreme precipitation to human-driven climate change
Phys.org July 7, 2021 Detecting anthropogenic forcing is difficult to detect in observational record. Researchers at UCLA used artificial neural networks to find patterns of extreme precipitation in weather records. They found multiple lines of evidence that human activity has intensified extreme precipitation during recent decades. Even when the data sets were widely different, they were able to see the human influence…read more. Open Access TECHNICAL ARTICLE
Harnessing the dark side
Nanowerk July 13, 2021 Optical singularities, which appear completely dark, typically occur when the phase of light with a specific wavelength, or color, is undefined. Researchers at Harvard University have developed a new way to control and shape optical singularities. The metasurface tilts the wavefront of light in a very precise manner over a surface so that the interference pattern of the transmitted light produces extended regions of darkness. Their approach allows precise engineering of dark regions with remarkably high contrast. Engineered singularities could be used to trap atoms in dark regions and improve super high-resolution imaging. As darkness has […]