Unsaturated bi-heterometal clusters in metal-vacancy sites of 2D MoS2 for efficient hydrogen evolution

The valence states and coordination structures of doped heterometal atoms in two-dimensional(2D)nanomaterials lack predictable regulation strategies.Hence,a robust method is proposed to form unsaturated heteroatom clusters via the metal-vacancy restraint mechanism,which can precisely regulate the bonding and valence state of heterometal atoms doped in 2D molybdenum disulfide.The unsaturated valence state of heterometal Pt and Ru cluster atoms form a spatial coordination structure with Pt–S and Ru–O–S as catalytically active sites.Among them,the strong binding energy of negatively charged suspended S and O sites for H+,as well as the weak adsorption of positively charged unsaturated heterometal atoms for H*,reduces the energy barrier of the hydrogen evolution reaction proved by theoretical calculation.Whereupon,the electrocatalytic hydrogen evolution performance is markedly improved by the ensemble effect of unsaturated heterometal atoms and highlighted with an overpotential of 84 mV and Tafel slope of 68.5 mV dec^(−1).In brief,this metal vacancy-induced valence state regulation of heterometal can manipulate the coordination structure and catalytic activity of heterometal atoms doped in the 2D atomic lattice but not limited to 2D nanomaterials.

Engineering electrolyte additives for stable zinc-based aqueous batteries:Insights and prospects

Zn-based aqueous batteries(ZABs) are gaining widespread popularity due to their low cost and high safety profile. However, the application of ZABs faces significant challenges, such as dendrite growth and parasitic reactions of metallic Zn anodes. Therefore, achieving high-energy–density ZABs necessitates addressing the fundamental thermodynamics and kinetics of Zn anodes. Various strategies are available to mitigate these challenges, with electrolyte additive engineering emerging as one of the most efficient and promising approaches. Despite considerable research in this field, a comprehensive understanding of the intrinsic mechanisms behind the high performance of electrolyte additives remains limited. This review aims to provide a detailed introduction to functional electrolyte additives and thoroughly explore their underlying mechanisms. Additionally, it discusses potential directions and perspectives in additive engineering for ZABs, offering insights into future development and guidelines for achieving high-performance ZABs.

A leap by the rise of solid-state electrolytes for Li-air batteries

Li-air batteries have attracted extensive attention because of their ultrahigh theoretical energy density. However, the potential safety hazard of flammable organic liquid electrolytes hinders their practical applications. Replacing liquid electrolytes with solidstate electrolytes(SSEs) is expected to fundamentally overcome the safety issues. In this work, we focus on the development and challenge of solid-state Li-air batteries(SSLABs). The rise of different types of SSEs, interfacial compatibility and verifiability in SSLABs are presented. The corresponding strategies and prospects of SSLABs are also proposed. In particular, combining machine learning method with experiment and in situ(or operando)techniques is imperative to accelerate the development of SSLABs.

Analyzing and relieving the thermal issues caused by fabrication details of a deuterium cryogenic target

In inertial confinement fusion experiments,fuel quality is determined mainly by the thermal environment of the capsule in the layering procedure.Owing to the absence of a radial thermal gradient,formed deuterium–deuterium(DD)ice shells in the capsule are thermally instable.To obtain a solid DD layer with good quality and long lifetime,stringent demands must be placed on the thermal performance of cryogenic targets.In DD cryogenic target preparation,two issues arise,even after the capsule’s temperature uniformity has been improved by the use of thick aluminized films.The first is the inconsistent ice shape,which is related to the capsule’s thermal field.In this article,some typical fabrication details are investigated,including adhesive penetration during assembly,the presence of the fill tube,the optical properties of the hohlraum and film surfaces,the jacket–hohlraum connection,deviations in capsule location,and asymmetrical contact at the arm–jacket interfaces.Detailed comparisons of the thermal effects of these factors provide guidance for target optimization.The second issue is the instability of seeding crystals in the fill tube due to unsteadiness of the direction of the thermal gradient in the fill tube assembly.An additional thermal controller is proposed,analyzed,and optimized to provide robust controllability of tube temperature.The analysis results and optimization methods presented in this article should not only help in dealing with thermal issues associated with DD cryogenic targets,but also provide important references for engineering design of other cryogenic targets.

A zincophilic molecular brush for a dendrite-free,corrosionresistant,zinc metal anode with a long life cycle

Zinc-based aqueous rechargeable batteries have attracted extensive attention due to their low cost,safety,and environmental friendliness.However,dendrite growth and hydrogen evolution of Zn anodes limit their large-scale application.A new strategy to produce a polyacrylamide/reduced graphene oxide(PAM@rGO)molecular nanobrush coating and control Zn electrolyte interface engineering is proposed for use in highly reversible Zn plating/stripping.Hydrogen evolution is inhibited,and Zn deposition is consolidated using the rich zincophilic functional groups of the branched polyacrylamide chain and the high conductivity of rGO.Due to the synergistic effects of corrosion resistance and dendrite-free growth,PAM@rGO/Zn provides prolonged and reversible Zn plating/stripping.Density functional theory(DFT)calculations expand on homogenized nucleation.The PAM@rGO/Zn||activated carbon(AC)capacitor exhibits long cyclic stability,fast ion transfer,and minimal interfacial impedance.This study provides experimental and theoretical bases for the structural design of Zn anode.

A mathematical model to assess the impact of testing and isolation compliance on the transmission of COVID-19

The COVID-19 pandemic has ravaged global health and national economies worldwide.Testing and isolation are effective control strategies to mitigate the transmission of COVID-19,especially in the early stage of the disease outbreak.In this paper,we develop a deterministic model to investigate the impact of testing and compliance with isolation on the transmission of COVID-19.We derive the control reproduction number R_(C),which gives the threshold for disease elimination or prevalence.Using data from New York State in the early stage of the disease outbreak,we estimate R_(C)=7:989.Both elasticity and sensitivity analyses show that testing and compliance with isolation are significant in reducing R_(C) and disease prevalence.Simulation reveals that only high testing volume combined with a large proportion of individuals complying with isolation have great impact on mitigating the transmission.The testing starting date is also crucial:the earlier testing is implemented,the more impact it has on reducing the infection.The results obtained here would also be helpful in developing guidelines of early control strategies for pandemics similar to COVID-19.

The Dynamics of Dopamine D_(2) Receptor-Expressing Striatal Neurons and the Downstream Circuit Underlying L-Dopa-Induced Dyskinesia in Rats

L-dopa(l-3,4-dihydroxyphenylalanine)-induced dyskinesia(LID)is a debilitating complication of dopamine replacement therapy for Parkinson’s disease.The potential contribution of striatal D_(2) receptor(D2R)-positive neurons and downstream circuits in the pathophysiology of LID remains unclear.In this study,we investigated the role of striatal D_(2)R+neurons and downstream globus pallidus externa(GPe)neurons in a rat model of LID.Intrastriatal administration of raclopride,a D_(2)R antagonist,significantly inhibited dyskinetic behavior,while intrastriatal administration of pramipexole,a D_(2)-like receptor agonist,yielded aggravation of dyskinesia in LID rats.Fiber photometry revealed the overinhibition of striatal D_(2)R+neurons and hyperactivity of downstream GPe neurons during the dyskinetic phase of LID rats.In contrast,the striatal D2R+neurons showed intermittent synchronized overactivity in the decay phase of dyskinesia.Consistent with the above findings,optogenetic activation of striatal D_(2)R+neurons or their projections in the GPe was adequate to suppress most of the dyskinetic behaviors of LID rats.Our data demonstrate that the aberrant activity of striatal D_(2)R+neurons and downstream GPe neurons is a decisive mechanism mediating dyskinetic symptoms in LID rats.