Ti3Si0.75Al0.25C2 Nanosheets as Promising Anode Material for Li-Ion Batteries

Herein we report that novel two-dimensional (2D) Ti3Si0.75Al0.25C2 (TSAC) nanosheets, obtained by sonically exfoliating their bulk counterpart in alcohol, performs promising electrochemical activities in a reversible lithiation and delithiation procedure. The as-exfoliated 2D TSAC nanosheets show significantly enhanced lithium-ion uptake capability in comparison with their bulk counterpart, with a high capacity of ≈350 mAh g−1 at 200 mA g−1, high cycling stability and excellent rate performance (150 mAh g−1 after 200 cycles at 8000 mA g−1). The enhanced electrochemical performance of TSAC nanosheets is mainly a result of their fast Li-ion transport, large surface area and small charge transfer resistance. The discovery in this work highlights the uniqueness of a family of 2D layered MAX materials, such as Ti3GeC2, Ti3SnC2 and Ti2SC, which will likely be the promising choices as anode materials for lithium-ion batteries (LIBs).

Numerical simulation of hydraulic performance with free overfall flow

Recently, free overfall flows have attracted attention of many researchers in the world. It is because the free overfall can be used as a tool in measuring the discharges and flows in any open channel systems or water collection systems for various flow regime at different shape of channels. In this study, the hydraulic performances of free overfall flow were explored using numerical simulation for three shapes of open channels including uniform rectangular, rectangular circumscribed, and rectangular inscribed steps. The hydraulic performances discussed in this study are including the flow regime, the maximum pressure, drop length and the energy dissipation rate. Numerical simulations were performed under different discharges Q (between 0.0005 m3/s and 0.0015 m3/s) and excise repair densities (y/H) for 1:2, 1:3 and 1:4. Visual observations identified various flow regimes with largely identical flow patterns in different discharges and configurations. Comparisons of properties indicated that there is a better depressurization and energy dissipation performances at the open channel with the shape of rectangular inscribed steps compare to the uniform rectangular in the small charge. Comparative study also revealed that the large excise repair densities of rectangular circumscribed steps might be optimal in terms of energy dissipation performances.

Tracks on films and multi-charged clusters

When conducting experiments on the electric explosion of titanium foil in water, a “strange” radiation was detected, leaving dotted traces on the film. The velocity of the carriers of this radiation was estimated as 20–40 m/s, and their energy, estimated by the Coulomb drag mechanism, turned out to be equal to 700 MeV. Subsequently, it was found that similar traces are formed at various types of high-current arc discharges, both of artificial and natural origin. Many solutions have been proposed to explain the nature of “strange” radiation, but none of them describes the details of the process of formation of dotted traces. We believe that these traces on the film could appear due to the action of charged micron-sized clusters. The possibility of the existence of clusters in the form of a nucleus from a certain number of similarly charged ions enclosed in a spherical shell of water molecules is shown. The force of the Coulomb repulsion of ions is compensated by the compression force of the shell polarized by the inhomogeneous electric field created by the nuclear charge. As the cluster approaches the surface of the film, a cluster with a small charge separates from it. It is accelerated in the electric field of a “large” cluster to energy of about 1 GeV. Having received a recoil momentum, a large cluster moves away from the film, braking in an inhomogeneous electric field, and then “falls” onto it again, and the process is repeated.

Existence of exponentially growing finite energy solutions for the charged Klein–Gordon equation on the de Sitter–Kerr–Newman metric

We show the existence of exponentially growing finite energy solutions for the charged Klein–Gordon equation on the De Sitter–Kerr–Newman metric for small charge and mass of the field and small angular momentum of the black hole. The mechanism behind is that the zero resonance that exists for zero charge, mass and angular momentum moves into the upper half plane.

Demonstration of a Remotely Piloted Atmospheric Measurement and Charge Release Platform for Geoengineering

Electric charge is always present in the lower atmosphere. If droplets or aerosols become charged, their behavior changes, influencing collision, evaporation, and deposition. Artificial charge release is an unexplored potential geoengineering technique for modifying fogs, clouds, and rainfall. Central to evaluating these processes experimentally in the atmosphere is establishing an effective method for charge delivery. A small charge-delivering remotely piloted aircraft has been specially developed for this, which is electrically propelled. It carries controllable bipolar charge emitters (nominal emission current ±5 μA) beneath each wing, with optical cloud and meteorological sensors integrated into the airframe. Meteorological and droplet measurements are demonstrated to 2 km altitude by comparison with a radiosonde, including within cloud, and successful charge emission aloft verified by using programmed flight paths above an upward-facing surface electric field mill. This technological approach is readily scalable to provide nonpolluting fleets of charge-releasing aircraft, identifying and targeting droplet regions with their own sensors. Beyond geoengineering, agricultural, and biological aerosol applications, safe ionic propulsion of future electric aircraft also requires detailed investigation of charge effects on natural atmospheric droplet systems.

Gravitational and Coulomb Potentials Interference in Heliosphere

Interference of gravitational and Coulomb potentials in the entire heliosphere is considered, it is being manifested in generation of two opposite flows of charged particles: 1) that are neutral or with a small charge to the Sun, and 2) in the form of a solar wind from the Sun. According to the Einstein --- Smoluchowski relation Te(R) = eDe / µe ~ (E/N)0.75 based on the N experimental values (heavy particles number density --- the ne electron concentration), the Te electron temperature in the entire heliosphere was for the first time analytically calculated depending on the charge of the Sun and distance to it R. Calculated values of the registered ion parameters in the solar wind were compared with experimental observations. Reasons for generating the ring current in inhomogeneous heliosphere and inapplicability of the Debye theory in describing processes in the solar wind (plasma with current) are considered

Fabrication of CoMN2O4 loaded nitrogen-doped graphene as bifunctional electrocatalyst for rechargeable zinc-air batteries

Designing durable and low-cost electrocatalysts for zinc-air batteries is critical, which plays an essential role in oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). In this paper, the CoMn2O4/N-RGO bifunctional electrocatalyst was synthesized by a facile hydrothermal method. The electrocatalytic performance was tested toward ORR and OER under alkaline condition (0.1[Formula: see text]M KOH). The XRD, SEM and other characterization analyses were used to investigate the physicochemical properties of materials. The results showed that the electrochemical activity of CoMn2O4/N-RGO showed high power density (354[Formula: see text]mW[Formula: see text]cm[Formula: see text], small charge/discharge voltage drop (0.70[Formula: see text]V) and excellent stability cycle (200[Formula: see text]h), which are superior to the noble metal Pt/C+IrO2 electrocatalyst (the voltage drop: 0.60[Formula: see text]V at initial and 0.85[Formula: see text]V after 13[Formula: see text]h). This work provided a new method for developing the bifunctional material in zinc-air batteries.

Localization and steric effect of the lone electron pair of the tellurium Te4+ cation and other cations of the p-block elements. A systematic study

A simple method has been developed based on pure geometrical concepts to localize lone pairs (LPs) of cations of the p-block elements and model their steric effect. The method was applied to 1185 structures containing LP cations in 2439 non-equivalent positions. For oxide crystal structures, it is observed that, going from bottom left to top right in the periodic table, LPs move away from the cation core and decrease in size. For a given kind of cation M*, the LP radius increases linearly with the M*–LP distance, the smallest rate being observed for Tl+ and the largest for Cl5+. The influence of the anion type was also studied in the case of the Te4+ cation. Overall, the same trends were observed. The smallest Te–LP distances and LP radii are found for anions of large size and small charge.