Membrane-less MoO_(3-x)@TiO_(2)-bromine battery with excellent rate capability and cyclic stability

Bromine has attracted significant attention as a cathode material for aqueous batteries due to its high reduction potential of 1.05 V(Br_(3)^(-)+2e~-■3Br~-),impressive theoretical specific capacity of 223 mA h g^(-1),and rapid reaction kinetics in the electrolyte.However,searching for compatible anode materials to match with bromine has posed a challenge due to its highly corrosive nature.In this study,we developed oxygen-deficient MoO_(3) with TiO_(2) coating(referred to as MoO_(3-x)@TiO_(2))as an anode material to pair with a bromine cathode in static full batteries.The oxygen deficiency contributes to enhanced electronic and protonic diffusion within the MoO_(3-x)lattice,while the TiO_(2) coating mitigates structural dissolution and proton trapping during cycling.The MoO_(3-x)@TiO_(2) demonstrates fast charge storage kinetics and excellent resistance to bromine corrosion.The impressive compatibility between MoO_(3-x)@TiO_(2) and bromine enables the construction of membrane-less full batteries with exceptional rate capability and cyclic stability.The MoO_(3-x)@TiO_(2)-bromine battery achieves an energy density of70.8 W h kg^(-1)at a power density of 328.1 W kg^(-1),showcasing an impressive long-term cyclic life of 20,000 cycles.Our study provides valuable insights for the development of high-performance aqueous secondary batteries.

中国式教育现代化背景下体育教师数字能力建设的价值维度与推进路径

本文采用文献资料法、逻辑分析法等研究方法,立足中国式教育现代化发展背景,解析体育教师数字能力建设价值维度,构建优质、高效的数字能力建设推进路径。研究发现,体育教师数字能力包括数字技术能力、数字价值与追求、数字教学能力、数字学习与创新4个层面。体育教师数字能力建设是实施新时代人才强国战略的应然指向、实现体育教育高质量发展的内在要求、推动中国式学校体育现代化的实然需要、促进体育教育创新的必然要素。体育教师数字能力建设推进路径包括:构建人机协同育人模式,助力教师与数字技术互补短板;激发教师内部学习动机,增强数字应用与创新能力;凝聚教师数字价值追求与认同,提高数字能力发展自我效能感;建设复合型数字人才队伍,推动中国式学校体育现代化发展。

社区老年人衰弱、高血压及跌倒风险的关系研究

目的老年人往往同时存在衰弱和高血压,这可能会导致跌倒风险。本研究旨在探讨社区老年人衰弱状态、高血压和跌倒风险之间的关系。方法采用便利抽样选取无锡市社区老年人401名,采用STEADI(Stopping Elderly Accidents,Deaths&Injuries)工具包中的跌倒自评清单评估老年人跌倒风险,采用衰弱筛查量表评估社区老年人衰弱状况,采用自设问卷调查老年人社会人口学资料和慢性病等情况。采用logistic回归分析、广义加性模型和曲线拟合等方法分析社区老年人衰弱、高血压及跌倒风险的相互关系。结果Logistic回归分析发现,衰弱与较高的跌倒风险密切相关(OR 8.52,95%CI 3.21-22.57;P<0.001),高血压显著增加跌倒风险(OR 1.87,95%CI 1.11~3.13;P=0.019)。高血压伴有衰弱的老年人跌倒风险最高(OR 12.24,95%CI 3.51~42.65)。广义加性模型和光滑曲线拟合结果显示,在高血压老年人中,衰弱和跌倒风险之间存在非线性关联;在衰弱前期到衰弱状态的进程中,老年高血压患者具有较高的跌倒倾向。结论衰弱和高血压独立且可共同增加社区老年人跌倒的风险。加强对社区老年人衰弱状况和高血压的管理可能有助于降低这一人群跌倒的风险。

Expert consensus on pediatric orthodontic therapies of malocclusions in children

Malocclusion,identified by the World Health Organization(WHO)as one of three major oral diseases,profoundly impacts the dental-maxillofacial functions,facial esthetics,and long-term development of~260 million children in China.Beyond its physical manifestations,malocclusion also significantly influences the psycho-social well-being of these children.Timely intervention in malocclusion can foster an environment conducive to dental-maxillofacial development and substantially decrease the incidence of malocclusion or reduce the severity and complexity of malocclusion in the permanent dentition,by mitigating the negative impact of abnormal environmental influences on the growth.Early orthodontic treatment encompasses accurate identification and treatment of dental and maxillofacial morphological and functional abnormalities during various stages of dental-maxillofacial development,ranging from fetal stages to the early permanent dentition phase.From an economic and societal standpoint,the urgency for effective early orthodontic treatments for malocclusions in childhood cannot be overstated,underlining its profound practical and social importance.This consensus paper discusses the characteristics and the detrimental effects of malocclusion in children,emphasizing critical need for early treatment.It elaborates on corresponding core principles and fundamental approaches in early orthodontics,proposing comprehensive guidance for preventive and interceptive orthodontic treatment,serving as a reference for clinicians engaged in early orthodontic treatment.

Binding SnO_(2)Nanoparticles with MoS_(2)Nanosheets Toward Highly Reversible and Cycle-Stable Lithium/Sodium Storage

SnO_(2),with its high theoretical capacity,abundant resources,and environmental friendliness,is widely regarded as a potential anode material for lithium-ion batteries(LIBs).Nevertheless,the coarsening of the Sn nanoparticles impedes the reconversion back to SnO_(2),resulting in low coulombic efficiency and rapid capacity decay.In this study,we fabricated a heterostructure by combining SnO_(2)nanoparticles with MoS_(2)nanosheets via plasma-assisted milling.The heterostructure consists of in-situ exfoliated MoS_(2)nanosheets predominantly in 1 T phase,which tightly encase the SnO_(2)nanoparticles through strong bonding.This configuration effectively mitigates the volume change and particle aggregation upon cycling.Moreover,the strong affinity of Mo,which is the lithiation product of MoS_(2),toward Sn plays a pivotal role in inhibiting the coarsening of Sn nanograins,thus enhancing the reversibility of Sn to SnO_(2)upon cycling.Consequently,the SnO_(2)/MoS_(2)heterostructure exhibits superb performance as an anode material for LIBs,demonstrating high capacity,rapid rate capability,and extended lifespan.Specifically,discharged/charged at a rate of 0.2 A g^(-1)for 300 cycles,it achieves a remarkable reversible capacity of 1173.4 mAh g^(-1).Even cycled at high rates of 1.0 and 5.0 A g^(-1)for 800 cycles,it still retains high reversible capacities of 1005.3 and 768.8 mAh g^(-1),respectively.Moreover,the heterostructure exhibits outstanding electrochemical performance in both full LIBs and sodium-ion batteries.

A Novel High-Efficiency Transaction Verification Scheme for Blockchain Systems

Blockchain can realize the reliable storage of a large amount of data that is chronologically related and verifiable within the system.This technology has been widely used and has developed rapidly in big data systems across various fields.An increasing number of users are participating in application systems that use blockchain as their underlying architecture.As the number of transactions and the capital involved in blockchain grow,ensuring information security becomes imperative.Addressing the verification of transactional information security and privacy has emerged as a critical challenge.Blockchain-based verification methods can effectively eliminate the need for centralized third-party organizations.However,the efficiency of nodes in storing and verifying blockchain data faces unprecedented challenges.To address this issue,this paper introduces an efficient verification scheme for transaction security.Initially,it presents a node evaluation module to estimate the activity level of user nodes participating in transactions,accompanied by a probabilistic analysis for all transactions.Subsequently,this paper optimizes the conventional transaction organization form,introduces a heterogeneous Merkle tree storage structure,and designs algorithms for constructing these heterogeneous trees.Theoretical analyses and simulation experiments conclusively demonstrate the superior performance of this scheme.When verifying the same number of transactions,the heterogeneous Merkle tree transmits less data and is more efficient than traditional methods.The findings indicate that the heterogeneous Merkle tree structure is suitable for various blockchain applications,including the Internet of Things.This scheme can markedly enhance the efficiency of information verification and bolster the security of distributed systems.

Chalcogenide Ovonic Threshold Switching Selector

Today’s explosion of data urgently requires memory technologies capable of storing large volumes of data in shorter time frames,a feat unattain-able with Flash or DRAM.Intel Optane,commonly referred to as three-dimensional phase change memory,stands out as one of the most promising candidates.The Optane with cross-point architecture is constructed through layering a storage element and a selector known as the ovonic threshold switch(OTS).The OTS device,which employs chalcogenide film,has thereby gathered increased attention in recent years.In this paper,we begin by providing a brief introduction to the discovery process of the OTS phenomenon.Subsequently,we summarize the key elec-trical parameters of OTS devices and delve into recent explorations of OTS materials,which are categorized as Se-based,Te-based,and S-based material systems.Furthermore,we discuss various models for the OTS switching mechanism,including field-induced nucleation model,as well as several carrier injection models.Additionally,we review the progress and innovations in OTS mechanism research.Finally,we highlight the successful application of OTS devices in three-dimensional high-density memory and offer insights into their promising performance and extensive prospects in emerging applications,such as self-selecting memory and neuromorphic computing.

3D Road Network Modeling and Road Structure Recognition in Internet of Vehicles

Internet of Vehicles (IoV) is a new system that enables individual vehicles to connect with nearby vehicles,people, transportation infrastructure, and networks, thereby realizing amore intelligent and efficient transportationsystem. The movement of vehicles and the three-dimensional (3D) nature of the road network cause the topologicalstructure of IoV to have the high space and time complexity.Network modeling and structure recognition for 3Droads can benefit the description of topological changes for IoV. This paper proposes a 3Dgeneral roadmodel basedon discrete points of roads obtained from GIS. First, the constraints imposed by 3D roads on moving vehicles areanalyzed. Then the effects of road curvature radius (Ra), longitudinal slope (Slo), and length (Len) on speed andacceleration are studied. Finally, a general 3D road network model based on road section features is established.This paper also presents intersection and road section recognition methods based on the structural features ofthe 3D road network model and the road features. Real GIS data from a specific region of Beijing is adopted tocreate the simulation scenario, and the simulation results validate the general 3D road network model and therecognitionmethod. Therefore, thiswork makes contributions to the field of intelligent transportation by providinga comprehensive approach tomodeling the 3Droad network and its topological changes in achieving efficient trafficflowand improved road safety.

Discharge and mass transfer characteristics of atmospheric pressure gas-solid two-phase gliding arc

In this work,a gas-solid two-phase gliding arc discharge(GS-GAD)reactor was built.Gliding arc was formed in the gap between the blade electrodes,and solid powder was deposited on the sieve plate positioned beneath the blade electrodes.A range of experimental parameters,including the inter-electrode spacing,gas flow rate,applied voltage,and the type of the powder,were systematically varied to elucidate the influence of solid powder matter on the dynamics of gliding arc discharge(GAD).The discharge images were captured by ICCD and digital camera to investigate the mass transfer characteristics of GS-GAD,and the electrical parameters,such as the effective values of voltage,current,and discharge power were record to reveal the discharge characteristics of GS-GAD.The results demonstrate that powder undergoes spontaneous movement towards the upper region of the gliding arc due to the influence of electric field force.Increasing the discharge voltage,decreasing relative dielectric constant of the powder and reducing the electrode-to-sieve-plate distance all contribute to a greater involvement of powder in the GAD process,subsequently resulting in an enhanced powder concentration within the GAD region.Additionally,powder located beneath the gliding arc experiences downward resistance caused by the opposing gas flow and arc.Excessive gas flow rate notably hampers the powder concentration within the discharge region,and the velocity of powder motion in the upper part of the GAD region is reduced.Under the condition of electrode-to-sieve-plate distance of 30 mm,gas flow rate of 1.5 L/min,and peak-to-peak voltage of 31 kV,the best combination of arc gliding and powder spark discharge phenomena can be achieved with the addition of Al_(2)O_(3) powder.

Identification of Early Warning Signals of Infectious Diseases in Hospitals by Integrating Clinical Treatment and Disease Prevention

The global incidence of infectious diseases has increased in recent years,posing a significant threat to human health.Hospitals typically serve as frontline institutions for detecting infectious diseases.However,accurately identifying warning signals of infectious diseases in a timely manner,especially emerging infectious diseases,can be challenging.Consequently,there is a pressing need to integrate treatment and disease prevention data to conduct comprehensive analyses aimed at preventing and controlling infectious diseases within hospitals.This paper examines the role of medical data in the early identification of infectious diseases,explores early warning technologies for infectious disease recognition,and assesses monitoring and early warning mechanisms for infectious diseases.We propose that hospitals adopt novel multidimensional early warning technologies to mine and analyze medical data from various systems,in compliance with national strategies to integrate clinical treatment and disease prevention.Furthermore,hospitals should establish institution-specific,clinical-based early warning models for infectious diseases to actively monitor early signals and enhance preparedness for infectious disease prevention and control.

TRPC6 Knockout Alleviates Renal Fibrosis through PI3K/AKT/GSK3B Pathway

Objective Renal fibrosis is the ultimate pathway of various forms of acute and chronic kidney damage.Notably,the knockout of transient receptor potential channel 6(TRPC6)has shown promise in alleviating renal fibrosis.However,the regulatory impact of TRPC6 on renal fibrosis remains unclear.Methods In vivo,TRPC6 knockout(TRPC6−/−)mice and age-matched 129 SvEv(WT)mice underwent unilateral renal ischemia-reperfusion(uIR)injury surgery on the left renal pedicle or sham operation.Kidneys and serum were collected on days 7,14,21,and 28 after euthanasia.In vitro,primary tubular epithelial cells(PTECs)were isolated from TRPC6−/−and WT mice,followed by treatment with transforming growth factorβ1(TGFβ1)for 72 h.The anti-fibrotic effect of TRPC6−/−and the underlying mechanisms were assessed through hematoxylin-eosin staining,Masson staining,immunostaining,qRT-PCR,and Western blotting.Results Increased TRPC6 expression was observed in uIR mice and PTECs treated with TGFβ1.TRPC6−/−alleviated renal fibrosis by reducing the expression of fibrotic markers(Col-1,α-SMA,and vimentin),as well as decreasing the apoptosis and inflammation of PTECs during fibrotic progression both in vivo and in vitro.Additionally,we found that the phosphatidylinositol 3-kinase(PI3K)/protein kinase B(AKT)/glycogen synthase kinase 3 beta(GSK3β)signaling pathway,a pivotal player in renal fibrosis,was down-regulated following TRPC6 deletion.Conclusion These results suggest that the ablation of TRPC6 may mitigate renal fibrosis by inhibiting the apoptosis and inflammation of PTECs through down-regulation of the PI3K/AKT/GSK3βpathway.Targeting TRPC6 could be a novel therapeutic strategy for preventing chronic kidney disease.

How Does Social Media Usage Intensity Influence Adolescents’Social Anxiety:The Chain Mediating Role of Imaginary Audience and Appearance Self-Esteem

Background:To reduce adolescents’social anxiety,the study integrates external factors(social media usage)with internal factors(imaginary audience and appearance-based self-esteem)to internal mechanisms of adolescents’social anxiety in the Internet age based on objective self-awareness theory and self-esteem importance weighting model.Methods:Utilizing the Social Media Usage Intensity Scale,Social Anxiety Scale,imaginary Audience Scale,and Physical Self Questionnaire,we surveyed 400 junior high school students from three schools in Hubei province,China.Results:A significantly positive correlation is revealed between the intensity of social media usage and both social anxiety and imaginary audience(p<0.001).Conversely,social media usage intensity and appearance self-esteem are significantly negatively correlated(p<0.001).Additionally,the perception of an imaginary audience was negatively correlated with appearance self-esteem(p<0.001).Furthermore,we found that imaginary audience(indirect effect of 0.14,95%CI=[0.02,0.07])and appearance self-esteem(indirect effect of 0.14,95%CI=[0.02,0.07])can respectively act as independent mediators between social networking site use intensity and social anxiety,Additionally,the relationship between imaginary audience and appearance self-esteem can also be chain-mediated(indirect effect of 0.03,95%CI=[0.00,0.02])separately affect the relationship between the two.Conclusion:The imaginary audience serves as an independent mediator that links social media usage intensity to social anxiety among adolescents.Additionally,the observed chain mediation effect involving both the imaginary audience and appearance self-esteem provides novel insights for developing strategies aimed at addressing adolescent social anxiety.

肝素酶、碱性成纤维细胞生长因子在非小细胞肺癌中的表达及与预后的关系

目的研究非小细胞肺癌(NSCLC)组织中肝素酶、碱性成纤维细胞生长因子(bFGF)的表达情况,分析其与肺癌转移和预后的关系。方法选取2012年6月—2014年6月河南省人民医院收治的48例NSCLC患者作为研究对象,所有患者均行手术治疗,术中取肺癌组织样本作为观察组,取癌旁组织样本作为对照组。观察肝素酶、b FGF在两组样本中的表达情况,分析肝素酶、b FGF表达与临床病理因素的关系。采用Logistic回归方程进行计算,探究NSCLC患者肝素酶、b FGF表达与转移和生存的关系。结果观察组中肝素酶阳性例数38例(79.17%),b FGF阳性例数37例(77.08%)。对照组中肝素酶、b FGF均为阴性表达,观察组肝素酶、b FGF阳性表达率与对照组比较差异有统计学意义(P <0.05)。肝素酶表达与NSCLC患者病理分期、血管浸润以及淋巴结转移有关;而b FGF表达则与NSCLC患者病理分期、分化程度、血管浸润及淋巴结转移有关。随访NSCLC患者3年,生存患者26例,生存率54.17%。死亡患者22例,病死率45.83%。NSCLC生存和死亡患者在分化程度、血管浸润、淋巴结转移及b FGF表达上差异有统计学意义(P <0.05)。将上述有差异因素带入Logistic回归方程分析发现,分化程度、血管浸润、淋巴结转移及b FGF表达均是NSCLC患者预后的影响因素。结论肝素酶、bFGF与NSCLC的转移、血管浸润等密切相关,与NSCLC的预后也有明显关系。

栀子苷抗肾间质纤维化的作用机制研究

目的通过转化生长因子-β1(TGF-β1)/Smad-2信号通路探讨栀子苷对肾间质纤维化的影响。方法将SD大鼠随机分为对照组、正常大鼠灌胃组、模型组、30 mg/kg及15 mg/kg栀子苷组,每组8只。复制大鼠单侧输尿管结扎(UUO)肾间质纤维化模型,栀子苷组连续给予栀子苷14 d,对照组和模型组灌胃同体积的生理盐水;实验结束后,取大鼠结扎侧的肾脏,用HE染色观察肾间质纤维化病理情况;全自动生化仪检测血肌酐和尿素氮;ELISA检测大鼠血清中白细胞介素-1β(IL-1β)、肿瘤坏死因子-α(TNF-α)、超氧化物歧化酶(SOD)活力和丙二醛(MDA)含量,Western blotting检测TGF-β1和Smad-2蛋白含量。结果与模型组比较,30 mg/kg和15 mg/kg栀子苷组大鼠血清中炎症因子TNF-α和IL-1β含量均降低(P <0.05),且呈剂量依赖性降低,MDA含量降低(P <0.05),SOD活性升高(P <0.05),且随着栀子苷浓度的增加而升高。与对照组比较,模型组肾脏组织中TGF-β1和Smad-2蛋白的表达增加(P <0.05);给予30和15 mg/kg的栀子苷后大鼠肾脏组织中TGF-β1和Smad-2蛋白表达降低(P <0.05)。结论栀子苷具有抗肾间质纤维化作用,其机制可能与通过抑制TGF-β1/Smad信号通路,降低炎症反应及氧化应激损伤有关。

中国顶尖三人篮球运动员训期睡眠状况分析研究

目的:该研究主要通过客观监测来了解我国顶尖三人篮球运动员在9周集训中的睡眠状况,为其合理安排作息训练及预防运动损伤提供一定的参考。方法:集训前,采用匹兹堡睡眠质量问卷(PSQI)对被测运动员睡眠状况进行筛查;集训中,通过实验测量法对男、女两队不同监测日睡眠状况及男队损伤指标进行对比分析。结果:集训前,睡眠质量问卷(PSQI)的7个维度中只有总睡眠时间得分男队非常明显高于女队(P<0.01),其他维度并无差异(P>0.05)。集训中,男队第2监测日及第3监测日的睡眠总时间都明显低于同时期的女队(P<0.05);并且男队第3日夜间觉醒次数明显高于女队(P<0.05),同时觉醒总时间也非常明显高于女队第3监测日(P<0.01)。男队纵向比较发现,第3监测日及第4监测日的夜间觉醒次数及觉醒总时间都明显高于其集训前(P<0.05),其中第4监测日的觉醒次数非常明显高于集训前(P<0.01)。男队纵向对比还发现,第4监测日的血液CK活性及IL-6含量都明显高于第3监测日(P<0.05)。结论:(1)被测运动员在集训前无睡眠障碍。(2)男队训期睡眠状况较女队差并不断恶化。(3)男队在训期恢复状况不佳,运动损伤加重。

基于超分子自组装策略定性和定量检测奶粉中的三聚氰胺

三聚氰胺是一种应用广泛的化工原料,但在摄入人体后会形成结石,对肾功能造成极大损伤。由于其含氮量高,常被不法商家添加在奶粉中以提高奶粉含氮量,因此在食品工业中三聚氰胺的定性定量检测十分重要。本研究利用超分子自组装的策略,以三聚氰胺与氰尿酸自组装作用为基础,利用亚甲基蓝作为反应指示剂,使用操作便捷的分光光度法对奶粉中的三聚氰胺进行定性和定量检测。本方法反应条件温和、颜色变化明显、检出限低、灵敏度高,也可拆分成多个环节实验,应用于不同学时的实验教学,是一个适合本科教学环境的新颖实验。

Catalytic Reduction of CO2 to CO via Reverse Water Gas Shift Reaction:Recent Advances in the Design of Active and Selective Supported Metal Catalysts

The catalytic conversion of CO2 to CO via a reverse water gas shift(RWGS)reaction followed by well-established synthesis gas conversion technologies may provide a potential approach to convert CO2 to valuable chemicals and fuels.However,this reaction is mildly endothermic and competed by a strongly exothermic CO2 methanation reaction at low temperatures.Therefore,the improvement in the low-temperature activities and selectivity of the RWGS reaction is a key challenge for catalyst designs.We reviewed recent advances in the design strategies of supported metal catalysts for enhancing the activity of CO2 conversion and its selectivity to CO.These strategies include varying support,tuning metal–support interactions,adding reducible transition metal oxide promoters,forming bimetallic alloys,adding alkali metals,and enveloping metal particles.These advances suggest that enhancing CO2 adsorption and facilitating CO desorption are key factors to enhance CO2 conversion and CO selectivity.This short review may provide insights into future RWGS catalyst designs and optimization.

Joint Allocation of Wireless Resource and Computing Capability in MEC-Enabled Vehicular Network

In MEC-enabled vehicular network with limited wireless resource and computation resource,stringent delay and high reliability requirements are challenging issues.In order to reduce the total delay in the network as well as ensure the reliability of Vehicular UE(VUE),a Joint Allocation of Wireless resource and MEC Computing resource(JAWC)algorithm is proposed.The JAWC algorithm includes two steps:V2X links clustering and MEC computation resource scheduling.In the V2X links clustering,a Spectral Radius based Interference Cancellation scheme(SR-IC)is proposed to obtain the optimal resource allocation matrix.By converting the calculation of SINR into the calculation of matrix maximum row sum,the accumulated interference of VUE can be constrained and the the SINR calculation complexity can be effectively reduced.In the MEC computation resource scheduling,by transforming the original optimization problem into a convex problem,the optimal task offloading proportion of VUE and MEC computation resource allocation can be obtained.The simulation further demonstrates that the JAWC algorithm can significantly reduce the total delay as well as ensure the communication reliability of VUE in the MEC-enabled vehicular network.

Fluorine-substituted O3-type NaNi_(0.4)Mn_(0.25)Ti_(0.3)Co_(0.05)O_(2-x)F_(x) cathode with improved rate capability and cyclic stability for sodium-ion storage at high voltage

O3-type Na NiO_(2)-based cathode materials undergo irreversible phase transition and serious capacity decay at high voltage above 4.0 V in sodium-ion batteries. To address these challenges, effects of Fsubstitution on the structure and electrochemical performance of Na Ni_(0.4)Mn_(0.25)Ti_(0.3)Co_(0.05)O_(2) are investigated in this article. The F-substitution leads to expanding of interlayer, which can enhance the mobility of Na+. NaNi_(0.4)Mn_(0.25)Ti_(0.3)Co_(0.05)O_(1.92)F_(0.08)(NMTC-F_(0.08)) with the optimal F-substitution degree exhibits much improved rate capability and cyclic stability. It delivers reversible capacities of 177 and 97 m Ah g^(-1) at 0.05 and 5 C within 2.0–4.4 V, respectively. Galvanostatic intermittent titration technique verifies faster kinetics of Na+diffusion in NMTC-F_(0.08). And in-situ XRD investigation reveals the phase evolution of NMTC-F_(0.08), indicating enhanced structural stability results from F-substitution. This study may shed light on the development of high performance cathode materials for sodium-ion storage at high voltage.

Effect of microstructure and passive film on corrosion resistance of 2507 super duplex stainless steel prepared by different cooling methods in simulated marine environment

The effect of microstructure and passive film on the corrosion resistance of 2507 super duplex stainless steel(SDSS)in simulated marine environment was investigated by electrochemical measurements,periodic wet–dry cyclic corrosion test,scanning Kelvin probe force microscopy,atomic force microscopy,and X-ray photoelectron spectrometry.The results show that the occupation ratio ofγphase increases with the decrease in cooling rate,whereas the content ofαphase reduces gradually.In addition,theσprecipitated phase only emerges in the annealed steel.The pitting sensitivity and corrosion rate of 2507 SDSS reduce first and then increase as the cooling rate decreases.Theσprecipitated phase drastically reduces the protective ability of the passive film and facilitates micro-galvanic corrosion of the annealed steel.For various microstructures,the pits are preferentially distributed within theσandγphases.The corrosion resistance of 2507 SDSS prepared by different cooling methods is closely related to the microstructure and structure(stability and homogeneity)of the passive film.Normalized steel shows an optimal corrosion resistance,followed by the quenched and annealed steels.