Research progress of alkaline earth metal iron-based oxides as anodes for lithium-ion batteries

Anode materials are an essential part of lithium-ion batteries(LIBs),which determine the performance and safety of LIBs.Currently,graphite,as the anode material of commercial LIBs,is limited by its low theoretical capacity of 372 mA·h·g^(−1),thus hindering further development toward high-capacity and large-scale applications.Alkaline earth metal iron-based oxides are considered a promising candidate to replace graphite because of their low preparation cost,good thermal stability,superior stability,and high electrochemical performance.Nonetheless,many issues and challenges remain to be addressed.Herein,we systematically summarize the research progress of alkaline earth metal iron-based oxides as LIB anodes.Meanwhile,the material and structural properties,synthesis methods,electrochemical reaction mechanisms,and improvement strategies are introduced.Finally,existing challenges and future research directions are discussed to accelerate their practical application in commercial LIBs.

Research progress on vanadium oxides for potassium-ion batteries

Potassium-ion batteries(PIBs)have been considered as promising candidates in the post-lithium-ion battery era.Till now,a large number of materials have been used as electrode materials for PIBs,among which vanadium oxides exhibit great potentiality.Vanadium oxides can provide multiple electron transfers during electrochemical reactions because vanadium possesses a variety of oxidation states.Meanwhile,their relatively low cost and superior material,structural,and physicochemical properties endow them with strong competitiveness.Although some inspiring research results have been achieved,many issues and challenges remain to be further addressed.Herein,we systematically summarize the research progress of vanadium oxides for PIBs.Then,feasible improvement strategies for the material properties and electrochemical performance are introduced.Finally,the existing challenges and perspectives are discussed with a view to promoting the development of vanadium oxides and accelerating their practical applications.

Tuning dual-atom mediator toward high-rate bidirectional polysulfide conversion in Li-S batteries

An emerging practice in the realm of Li-S batteries lies in the employment of single-atom catalysts(SACs)as effective mediators to promote polysulfide conversion,but monometallic SACs affording isolated geometric dispersion and sole electronic configuration limit the catalytic benefits and curtail the cell performance.Here,we propose a class of dual-atom catalytic moieties comprising hetero-or homo-atomic pairs anchored on N-doped graphene(NG)to unlock the liquid–solid redox puzzle of sulfur,readily realizing Li-S full cell under high-rate-charging conditions.As for Fe-Ni-NG,in-depth experimental and theoretical analysis reveal that the hetero-atomic orbital coupling leads to altered energy levels,unique electronic structures,and varied Fe oxidation states in comparison with homo-atomic structures(FeFe-NG or Ni-Ni-NG).This would weaken the bonding energy of polysulfide intermediates and thus enable facile electrochemical kinetics to gain rapid liquid-solid Li_(2)S_(4)?Li_(2)S conversion.Encouragingly,a Li-S battery based on the S@Fe-Ni-NG cathode demonstrates unprecedented fast-charging capability,documenting impressive rate performance(542.7 mA h g^(-1)at 10.0 C)and favorable cyclic stability(a capacity decay of 0.016%per cycle over 3000 cycles at 10.0 C).This finding offers insights to the rational design and application of dual-atom mediators for Li-S batteries.

Double-Layer-Optimizing Method of Hybrid Energy Storage Microgrid Based on Improved Grey Wolf Optimization

To reduce the comprehensive costs of the construction and operation of microgrids and to minimize the power fluctuations caused by randomness and intermittency in distributed generation,a double-layer optimizing configuration method of hybrid energy storage microgrid based on improved grey wolf optimization(IGWO)is proposed.Firstly,building a microgrid system containing a wind-solar power station and electric-hydrogen coupling hybrid energy storage system.Secondly,the minimum comprehensive cost of the construction and operation of the microgrid is taken as the outer objective function,and the minimum peak-to-valley of the microgrid’s daily output is taken as the inner objective function.By iterating through the outer and inner layers,the system improves operational stability while achieving economic configuration.Then,using the energy-self-smoothness of the microgrid as the evaluation index,a double-layer optimizing configuration method of the microgrid is constructed.Finally,to improve the disadvantages of grey wolf optimization(GWO),such as slow convergence in the later period and easy falling into local optima,by introducing the convergence factor nonlinear adjustment strategy and Cauchy mutation operator,an IGWO with excellent global performance is proposed.After testing with the typical test functions,the superiority of IGWO is verified.Next,using IGWO to solve the double-layer model.The case analysis shows that compared to GWO and particle swarm optimization(PSO),the IGWO reduced the comprehensive cost by 15.6%and 18.8%,respectively.Therefore,the proposed double-layer optimizationmethod of capacity configuration ofmicrogrid with wind-solar-hybrid energy storage based on IGWO could effectively improve the independence and stability of the microgrid and significantly reduce the comprehensive cost.

尼古丁的“口供”

以口供的形式介绍了尼古丁的分子结构和部分生理功能,通过真实案件揭示尼古丁对人体的毒性。结合医学知识,阐述了尼古丁中毒的过程、吸烟上瘾的机理和尼古丁对人体的损害,并对人类健康生活提出禁烟建议。

Bio-templated formation of defect-abundant VS2 as a bifunctional material toward high-performance hydrogen evolution reactions and lithium-sulfur batteries

Transition metal chalcogenides have nowadays garnered burgeoning interest owing to their fascinating electronic and catalytic properties,thus possessing great implications for energy conversion and storage applications.In this regard,their controllable synthesis in a large scale at low cost has readily become a focus of research.Herein we report diatomite-template generic and scalable production of VS2 and other transition metal sulfides targeting emerging energy conversion and storage applications.The conformal growth of VS2over diatomite template would endow them with defect-abundant features.Throughout detailed experimental investigation in combination with theoretical simulation,we reveal that the enriched active sites/sulfur vacancies of thus-derived VS2 architectures would pose positive impacts on the catalytic performance such in electrocatalytic hydrogen evolution reactions.We further show that the favorable electrical conductivity and highly exposed sites of VS2 hold promise for serving as sulfur host in the realm of Li-S batteries.Our work offers new insights into the templated and customized synthesis of defect-rich sulfides in a scalable fashion to benefit multifunctional energy applications.

Non-precious metal electrocatalysts for two-electron oxygen electrochemistry: Mechanisms, progress, and outlooks

Hydrogen peroxide (H_(2)O_(2)) is a valuable chemical for a wide variety of applications. The environmentally friendly production route of the electrochemical reduction of O_(2)to H_(2)O_(2) has become an attractive alternative to the traditional anthraquinone process. The efficiency of electrosynthesis process depends considerably on the availability of cost-effective catalysts with high selectivity, activity, and stability.Currently, there are many outstanding issues in the preparation of highly selective catalysts, the exploration of the interface electrolysis environment, and the construction of electrolysis devices, which have led to extensive research efforts. Distinct from the existing few comprehensive review articles on H_(2)O_(2) production by two-electron oxygen reduction, the present review first explains the principle of the oxygen reduction reaction and then highlights recent advances in the regulation and control strategies of different types of catalysts. Key factors of electrode structure and device design are discussed. In addition,we highlight the promising co-production combination of this system with renewable energy or energy storage systems. This review can help introduce the potential of oxygen reduction electrochemical production of high-flux H_(2)O_(2) to the commercial market.

Morphological Correlates of the Phonatory Organ in an Ultrasonically Phonating Frog

The concave-eared torrent frog(Odorrana tormota) is the first species of tailless amphibian that was evidenced to phonate and detect ultrasounds. We employed anatomic and histological methods to examine the phonatory organs, including the floor of the buccal cavity, vocal cords and glottis, of O. tormota and its sympatric species including O. graminea, O. schmackeri, and Amolops wuyiensis with different fundamental frequencies, and Pelophylax nigromaculatus as a control. Our results reveal that O. tormota possesses specialized phonatory organ structures, with thinner vocal cords modulated by a moderately stronger muscular mastoideus between the medial vocal cords and the lateral cricoid cartilages, and more elastic mouth floor to likely supply faster air stream which could make the vocal cords vibrate at higher frequencies, larger relative distance between the two muscles m. intermandibulares(RDMI), and higher nucleus density of m. intermandibularis(NDMI) and m. geniohyoideus(NDMG). The results of Pearson's correlation tests between the mean values of the above measurements and the fundamental frequencies from the five species imply that all the specialized phonatory organ structures mentioned above might be favored by higher frequency of phonation of O. tormota.

Heterointerface engineering in hierarchical assembly of the Co/Co(OH)_(2)@carbon nanosheets composites for wideband microwave absorption

Heterogeneous interface engineering strategy is an effective method to optimize electromagnetic functional materials.However,the mechanism of heterogeneous interfaces on microwave absorption is still unclear.In this study,abundant heterointerfaces were customized in hierarchical structures via a collaborative strategy of lyophilization and hard templates.The impressive electromagnetic heterostructures and strong interfacial polarization were realized on the zero-dimensional(0D)hexagonal close-packed(hcp)-face-centered cubic(fcc)Co/two-dimensional(2D)Co(OH)_(2)nanosheets@three-dimensional(3D)porous carbon nanosheets(Co/Co(OH)_(2)@PCN).By controlling the carbonization temperature,the electromagnetic parameters were further adjusted to broaden the effective absorption bandwidth(EAB).Accordingly,the EAB of these absorbers were almost greater than 6 GHz(covering the entire Ku-band)in the thickness range of 2.0–2.2 mm except the sample S-1.0-800.As far as to the S-0.8-700 achieved an EAB up to 7.1 GHz at 2.2 mm and the minimum reflection loss(RLmin)value was−25.8 dB.Moreover,in the far-field condition,the radar cross section(RCS)of S-0.8-700 can be reduced to 19.6 dB·m^(2).We believe that this work will stimulate interest in interface engineering and provide a direction for achieving efficient absorbing materials.

Controllable heterogeneous interfaces and dielectric regulation of hollow raspberry-shaped Fe_(3)O_(4)@rGO hybrids for high-performance electromagnetic wave absorption

Heterogeneous interface engineering is closely related to the structural design of electromagnetic absorbers;thus,the interface control through structural design is a considerable approach to optimize the electromagnetic wave absorption(EWA)performance.Herein,the 3D hierarchical structure composites composed of two-dimensional reduced graphite oxide(rGO)and hollow raspberry Fe_(3)O_(4) nanoparticles was successfully fabricated by a simple pyrolysis and self-assembly process.This specific structure enriches the characteristics of interface polarization and dipole polarization,which further induces significant EWA behavior.By adjusting the amount of graphite oxide(GO),the complex dielectric constant of the obtained hybrids can be controlled,and the heterointerface can be cleverly adjusted.The minimum reflection loss(RLmin)of the typical products can be up to−73.86 dB at the thickness is only 1.35 mm,and the maximum effective absorption bandwidth(EAB)can reach 5.1 GHz.This work demonstrates that the unique structure and tunable components can fully improve the potential of electromagnetic absorption performance,which provides basic guidance for the heterogeneous interface engineering of efficient electromagnetic functional materials.

Understanding the efficient microwave absorption for Fe Co@ZnO flakes at elevated temperatures a combined experimental and theoretical approach

Considerable microwave absorption performance at elevated temperatures is highly demanded in both civil and military fields.Single dielectric or magnetic absorbers are difficult to attain efficient and broadband microwave absorption at the high temperature range of 373 K-573 K,and the evolution mechanism of the microwave absorption is still unclear especially for the magnetic absorbers.Herein,ZnO coated flaky-FeCo composite is proposed to break through the bottleneck,which possesses microwave absorption(RL<-10 dB)that covering the whole X band(8.2 GHz-12.4 GHz)at the temperature range of 298 K-573 K with a thickness of only~2 mm.Moreover,attenuation mechanism and evolution of the microwave absorption properties for the FeCo@ZnO flaky material at elevated temperature has been clearly disclosed by the composition and microstructure characterizations,electromagnetic performance measurements and first principles calculations for the first time.Moreover,the Poynting vector,volume loss density,magnetic field(H)and electric field(E)are simulated by HFSS to understand the interaction between EM waves and the samples at different temperatures,further elaborating the attenuation mechanism in high-temperature environment.This study provides guidance in designing and developing high-temperature microwave absorbers for the next generation.

Efficacy of a mineralized collagen bone-grafting material for peri-implant bone defect reconstruction in mini pigs

The mechanism of the mineralization process induced by natural mineralized collagen(MC)has been investigated for decades.The purpose of this study was to investigate the efficacy of selfassembled MC for peri-implant bone defect reconstruction in a mini pig.A standardized peri-implant bone defect model was created using 14 mini pig mandibles.Two materials were evaluated,i.e.a mixture of hydroxyapatite and collagen(Type A,TA),and self-assembled MC(Type B,TB).Bio-Oss(BO)and untreated(blank control,BC)groups were used as controls.After 3-and 6-month healing periods,the mini pigs were sacrificed for histomorphometric and microcomputed tomography analysis.After 3 months of healing,the average alveolar ridge height was 3.2761.57mm for group TA,3.28±2.02mm for group TB and 3.37±1.09mm for group BO,while group BC showed the lowest height of 2.68±0.47mm.After 6 months of healing,the average alveolar ridge height was 2.64±1.13mm for group TA,4.31±1.80mm for group TB and 3.8761.38mm for group BO,while group BC showed the lowest height of 2.48±1.80mm.The experimental groups and control group showed similar bone volume density,bone complexity and histological reaction.The self-assembled MC(Type B)stimulated new bone formation in the reconstruction of deficient alveolar ridges around the dental implant;it also displayed excellent clinical operability compared with bone grafts without collagen.

The tumor suppressor CYLD controls epithelial morphogenesis and homeostasis by regulating mitotic spindle behavior and adherens junction assembly

Epithelial morphogenesis and homeostasis are essential for animal development and tissue regeneration,and epithelial disorganization is associated with developmental disorders and tumorigenesis.However,the molecular mechanisms that contribute to the morphogenesis and homeostasis of the epithelium remain elusive.Herein,we report a novel role for the cylindromatosis(CYLD)tumor suppressor in these events.Our results show that CYLD depletion disrupts epithelial organization in both Drosophila egg chambers and mouse skin and intestinal epithelia.Microscopic analysis of proliferating cells in mouse epithelial tissues and cultured organoids reveals that loss of CYLD synergizes with tumor-promoting agents to cause the misorientation of the mitotic spindle.Mechanistic studies show that CYLD accu?mulates at the cell cortex in epithelial tissues and cultured cells,where it promotes the formation of epithelial adherens junctions through the modulation of microtubule dynamics.These data suggest that CYLD controls epithelial morphogenesis and homeostasis by modulating the assembly of adherens junctions and ensuring proper orientation of the mitotic spindle.Our findings thus provide novel insight into the role of CYLD in development,tissue homeostasis,and tumorigenesis.

Magnetic Ganoderma Lucidum Spores(mGLS):A Novel Regulatable Targeted Drug Delivery System

In the past decades,many materials have been studied as carriers for targeted drug delivery.However,there is a need for utilizable and selective carrier materials with few side effects.Here,the magnetic Ganoderma Lucidum Spores(mGLS)as a highly efficient targeted drug delivery carrier were explored.Then the regulatable targeted drug delivery system was verified by loading and releasing of the 5-Fluorouracil(5-FU).The results showed that the maximum of the loaded 5-FU reached 250.23 mg·g^(−1)in the mGLS.The cumulative release of the 5-FU for the drug delivery system could reach 80.11%and 67.14%in the PBS and HCl after 48 h,respectively.In addition,this system showed the good pharmacokinetic properties in vivo.After 12 h,the blood concentration in the 5-FU@mGLS group kept at 5.3µg·mL^(−1)and was four times higher than that in the 5-FU group.In summary,the GLS as a natural microscale core-shell structures appears the striking application in carrier material for oral drug delivery.

Current knowledge of COVID-19:Advances,challenges and future perspectives

The pandemic of coronavirus disease 2019(COVID-19)has already evoked massive influence.The global pandemic has been ravaging the whole world for a year,with the number of confirmed human infection cases over 150 million and a death toll exceeding 3 million.Although the genomic sequence of the cognate pathogen SARS-CoV-2(severe acute respiratory syndrome coronavirus 2)has been quickly determined,there are still many unknown aspects,including the virus origin and evolution trend,and the effectiveness of current vaccines and drugs against the mutating virus.This review summarizes current knowledge and advances about COVID-19,including virus origin,transmission and infection,with the aim to improve the understanding of COVID-19 and provide a new perspective for future studies.