Magnetic flux ropes (MFRs), sets of coherently twisted magnetic field lines, are believed as core structures of various solar eruptions. Their evolution plays an important role to understand the physical mechanisms of solar eruptions, and can shed light on adverse space weather near the Earth. However, the erupting MFRs are occasionally prevented by strong overlying magnetic fields, and the MFR evolution during the descending phase in the confined cases is lacking attention. Here, we present the deformation of an erupting MFR accompanied by a confined double-peaked solar flare. The first peak corresponded to the MFR eruption in a standard flare model, and the second peak was closely associated with the flashings of an underlying sheared arcade (SA), the reversal slipping motion of the L-shaped flare ribbon, the falling of the MFR, and the shifting of top of filament threads. All results suggest that the confined MFR eruption involved in two-step magnetic reconnection presenting two distinct episodes of energy release in the flare impulsive phase, and the latter magnetic reconnection between the confined MFR, and the underlying SA caused the deformation of the MFR. It is proposed that an intergrated evolution for confined MFR eruptions can compose of three stages: the eruption, the confinement, and the deformation.

We establish a cosmological-model-independent method to determine the Hubble constantH ₀ from the localized fast radio bursts (FRBs) and the Hubble parameter measurements from cosmic chronometers and obtain a first such determinationH ₀ = 71 ± 3 km s⁻¹ Mpc⁻¹, with an uncertainty of 4%, from the eighteen localized FRBs and nineteen Hubble parameter measurements in the redshift range 0 0 can be decreased to the level of that from the nearby SNe Ia when mock data from 500 localized FRBs with 50 Hubble parameter measurements in the redshift range of 0 0 in the very near future, which will help us to figure out the possible origin of the Hubble constant disagreement.

We measure current helicity ( H _r ^c ) as well as proxies for twist ( α _r ) and writhe ( W ) in the isolated magnetic knots of three delta ( δ )-sunspots and report that the observations are consistent with a kink instability acting on a highly twisted flux tube.δ -spots are active regions (ARs) in which positive and negative umbrae share a penumbra. We identify and isolate "magnetic knots," i.e., opposite polarity umbrae that are in close proximity and forming theδ -configuration, in ARs NOAA 11158, 11267, and 11476 as observed with data from the Solar Dynamic Observatory Helioseismic and Magnetic Imager. We find thatH _r ^c ,α _r , andWhave the same sign for each magnetic knot, as predicted in simulations of a kink instability acting on highly twisted flux tubes. The deformed flux tube causing theδ -formation, the magnetic knot, is only a portion of the entire AR and demonstrates the potential for the kink instability to act on a smaller spatial scale within the AR. Each magnetic footpoint contains a single sign of the radial current,J _r , which suggests that we are observing the core of the flux rope without return currents. As a counterexample, we analyze oneβ -spot that showsH _r ^c andα _r have the opposite signs ofW . While our observations support the formation mechanism of the magnetic knots inδ -spots being the kink instability, a much larger sample is needed to determine confidently the prevalence of the kink instability as the cause of flux tube deformation.

Smart construction of battery-type anodes with high rate and good mechanical properties is significant for advanced sodium ion capacitors (SICs). Herein, a flexible film consisting of MoO2 subnanoclusters encapsulated in nitrogen-doped carbon nanofibers (MoO2 SCs@N-CNFs) is designed and synthesized via electrospinning toward SICs as anodes. The strong N-Mo interaction guarantees the stable yet uniform dispersion of high loading MoO2 SCs (≈40 wt.%) in the flexible carbonaceous substrate. The sub-nanoscale effect of SCs restrains electrode pulverization and improves the Na+ diffusion kinetics, rendering better pseudocapacitance-dominated Na+-storage properties than the nanocrystal counterpart. The MoO2 SCs@N-CNFs paper with mass loadings of 2.2–10.1 mg cm−2 can be directly used as free-standing anode for SICs, which exhibit high reversible gravimetric/areal capacities both in liquid and quasi-solid-state electrolytes. The assembled flexible SICs competitively exhibit exceptional energy density and cycling stability. More significantly, the sub-nanoscale engineering strategy here is promisingly generalized to future electrode design for other electrochemical energy-related applications and beyond.

A high-performance all-inorganic magnesium–lithium chloride complex (MLCC) electrolyte is synthesized by a simple room-temperature reaction of LiCl with MgCl2 in tetrahydrofuran (THF) solvent. Molecular dynamics simulation, density functional theory calculation, Raman spectroscopy, and nuclear magnetic resonance spectroscopy reveal that the formation of [MgxLiyCl2x+y·nTHF] complex solvation structure significantly lowers the coordination number of THF in the first solvation sheath of Mg2+, which significantly enhances its de-solvation kinetics. The MLCC electrolyte presents a stable electrochemical window up to 3.1 V (vs Mg/Mg2+) and enables reversible cycling of Mg metal deposition/stripping with an outstanding Coulombic efficiency up to 99% at current densities as high as 10 mA cm−2. Utilizing the MLCC electrolyte, a Mg/Mo6S8 full cell can be cycled for over 10 000 cycles with a superior capacity retention of 85 mA h g−1 under an ultrahigh rate of 50 C (1 C = 128.8 mA g−1). The facile synthesis of high-performance MLCC electrolyte provides a promising solution for future practical magnesium batteries.