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Cellulose nanofibers (CNF) have a wide range of applications in daily life, yet their inherent flammability poses potential fire hazards and risks. Enhancing the flame resistance of CNF is a challenging task. Inspired by the layered "brick-and-mortar" architecture of nacre, a novel flame-retardant material was prepared in this work. The process involved modification of cellulose-rich pulp paper with a solution containing phytic acid and urea, creating phytic acid-modified cellulose nanofibers (PA-CNF) through a mechanical shearing technique. Subsequently, PA-CNF and graphene oxide (GO) were utilized as assembly units, with calcium chloride (CaCl2) serving as a crosslinking agent. A nacre-mimetic film was fabricated via layer-by-layer coating and hot pressing, with GO as "bricks" and PA-CNF as the "mortar". The flame retardancy of PA-CNF was significantly enhanced following phytic acid modification, and the resultant nacre-mimetic material demonstrated remarkable flame retardancy and mechanical properties, achieving a state of complete non-flammability. The nacre-mimetic structure provides superior insulation against heat, oxygen, and smoke, thereby enhancing safety measures. Moreover, the mixed solution of PA-CNF and GO has potential applications as flame retardant and thermal insulation coatings. [ABSTRACT FROM AUTHOR]

The foundation for ecological protection and high-quality development in the Yellow River Basin lies in the rational development of industry. This study systematically analyzes the current state of industrial development in the Yellow River Basin, examining traditional industries, strategic emerging industries, and future industries. Based on this analysis, it identifies key issues and development directions. The study reveals that the industrial structure in the Yellow River Basin is unreasonable; traditional industries have short chains and high energy consumption; the cultivation of strategic emerging industries is inadequate and poorly aligned; and comprehensive planning for future industries is inadequate. Therefore, it is imperative to systematically optimize the industrial structure in the Yellow River Basin, promote the transformation and upgrading of traditional industries, accelerate the cultivation of strategic emerging industries through technological innovation, and plan the development of future industries from a holistic perspective. This approach will enhance the momentum and vitality necessary for advancing ecological protection and high-quality development in the Yellow River Basin, contributing to a new chapter in the western development. [ABSTRACT FROM AUTHOR]

Electrocatalytic urea synthesis from CO2 and nitrogenous substances represents an essential advance for the chemical industry, enabling the efficient utilization of resources and promoting sustainable development. However, the development of electrocatalytic urea synthesis has been severely limited by weak chemisorption, poor activation and difficulties in C–N coupling reactions. In this review, catalysts and corresponding reaction mechanisms in the emerging fields of bimetallic catalysts, MXenes, frustrated Lewis acid–base pairs and heterostructures are summarized in terms of the two central mechanisms of molecule–catalyst interactions as well as chemical bond cleavage and directional coupling, which provide new perspectives for improving the efficiency of electrocatalytic synthesis of urea. This review provides valuable insights to elucidate potential electrocatalytic mechanisms. [ABSTRACT FROM AUTHOR]

High-velocity atomic clouds in the Galactic centre have attracted significant attention due to their enigmatic formation process, which is potentially linked to the starburst or supermassive black hole activities in the region. Further, the discovery of high-velocity molecular clouds (HVMCs) presents a greater puzzle, because they are much denser and more massive. If the HVMCs were accelerated by the strong activities in the Galactic centre, they are expected to be destroyed before they reach such a high velocity. To shed light on this phenomenon, we perform 3D numerical simulations to investigate the origin and hydrodynamic evolution of HVMCs during a starburst in the Galactic centre. We find that the presence of a magnetic field provides effective protection and acceleration to molecular clouds (MCs) within the galactic winds. Consequently, the MCs can attain latitudes of approximately 1 kpc with velocities around 200 km s−1, consistent with the observed characteristics of HVMCs. The consistency of our findings across a wide parameter space supports the conclusion that HVMCs can indeed withstand the starburst environment in the Galactic centre, providing valuable insights into their survival mechanisms. [ABSTRACT FROM AUTHOR]

To enhance the simulation efficiency of the EDEM discrete element numerical simulation software for coal powder mineral particles, experimental data on the rest angle of coal powder particles were collected as the response variable. Five parameters related to coal powder particles within the Hertz-Mindlin no-slip contact model were selected for investigation. Initially, the Plackett-Burman experiment identified three parameters: collision restitution coefficient, static friction coefficient, and rolling friction coefficient, significantly influencing the resting angle. Subsequently, the steepest ascent experiment determined the significant parameter ranges as follows: the collision restitution coefficient ranged from 0.20 to 0.40, the particle-particle static friction coefficient ranged from 0.30 to 0.50, and the particle-particle dynamic friction coefficient ranged from 0.06 to 0.10. Finally, the second-order regression model for the angle of repose and the saliency parameters was developed and optimized using the Box-Behnken experimental design. The following parameter combination was obtained: the collision recovery coefficient was 0.30, the particle-particle static friction coefficient was 0.49, and the particle-particle dynamic friction coefficient was 0.09. This study aimed to compare the angle of repose between the simulation experiment and the actual experiment. The relative error was only 1.02%, indicating that the simulation experiment achieved the optimal parameter combination. [ABSTRACT FROM AUTHOR]

Low temperature ionic conducting materials such as OH - and H + ionic conductors are important electrolytes for electrochemical devices. Here we show the discovery of mixed OH - /H + conduction in ceramic materials. SrZr 0.8 Y 0.2 O 3-δ exhibits a high ionic conductivity of approximately 0.01 S cm -1 at 90 °C in both water and wet air, which has been demonstrated by direct ammonia fuel cells. Neutron diffraction confirms the presence of OD bonds in the lattice of deuterated SrZr 0.8 Y 0.2 O 3-δ . The OH - ionic conduction of CaZr 0.8 Y 0.2 O 3-δ in water was demonstrated by electrolysis of both H 2 18 O and D 2 O. The ionic conductivity of CaZr 0.8 Y 0.2 O 3-δ in 6 M KOH solution is around 0.1 S cm -1 at 90 °C, 100 times higher than that in pure water, indicating increased OH - ionic conductivity with a higher concentration of feed OH - ions. Density functional theory calculations suggest the diffusion of OH - ions relies on oxygen vacancies and temporarily formed hydrogen bonds. This opens a window to discovering new ceramic ionic conducting materials for near ambient temperature fuel cells, electrolysers and other electrochemical devices., (© 2024. The Author(s).)