Substrate topography as a powerful tool to modify glial cell biology and interactions

Traumatic injuries to the central nervous system(CNS) result in disruption of the intricate network of axons which connect functionally related neurons that are widely distributed throughout the brain and spinal cord.Under normal conditions,maintenance of this complex system is structurally and functionally supported by astrocytes (ACs)and other glial cells,the processes of which form a framework surrounding neuronal cell bodies,dendrites,axons,and synapses.

面向未来低碳道路养护的超薄罩面功能性研究综述

Highway maintenance mileage reached 5.25 million kilometers in China by 2021.Ultra-thin overlay is one of the most commonly used maintenance technologies,which can significantly enhance the economic and environmental benefits of pavements.To promote the low-carbon development of ultrathin overlays,this paper mainly studied the mechanism and influencing factors of several ultra-thin overlay functions.Firstly,the skid resistance,noise reduction,rutting resistance,and crack resistance of ultrathin overlays were evaluated.The results indicated that the high-quality aggregates improved the skid and rutting resistance of ultra-thin overlay by 5%-20%.The optimized gradations and modified binders reduced noise of ultra-thin overlay by 0.4-6.0 dB.The high viscosity modified binders improved the rutting resistance of ultra-thin overlay by about 10%-130%.Basalt fiber improved the cracking resistance of ultra-thin overlay by more than 20%.Due to the thinner thickness and better road performance,the performance-based engineering cost of ultra-thin overlay was reduced by about 30%-40%compared with conventional overlays.Secondly,several environmentally friendly functions of ultra-thin overlay were investigated,including snow melting and deicing,exhaust gas purification and pavement cooling.The lower thickness of ultra-thin overlay was conducive to the diffusion of chloride-based materials to the pavement surface.Therefore,the snow melting effect of self-ice-melting was better.In addition,the ultra-thin overlay mixture containing photocatalytic materials could decompose 20%-50%of the exhaust gas.The colored ultra-thin overlay was able to reduce the temperature of the pavement by up to 8.1℃.The temperature difference between the upper and lower surfaces of the ultra-thin overlay containing thermal resistance materials could reach up to 12.8℃.In addition,numerous typical global engineering applications of functional ultra-thin overlay were summarized.This review can help better understand the functionality of ultra-thin overlays and promote the realization of future multi-functional and low-carbon road maintenance.

颗粒材料各向异性弹性波速与微观组构CT试验研究

针对颗粒材料的各向异性力学特征,利用带有两对弯曲元波速传感器的GDS圆柱扭剪仪,从宏观上研究了不同应力条件下聚氯乙烯颗粒试样中不同方向压缩波和剪切波的波速特征及波速各向异性程度的演化规律。同时,结合X射线CT扫描技术重构试样的三维结构模型,提取了接触配位数、接触法向、颗粒长轴方向等微观组构参数,并分析了其随应力状态改变的变化规律,从微观层面揭示了宏观波速各向异性演化的内在机理。研究结果表明:等向固结应力条件下,试样中波速呈现出显著的初始各向异性,即水平向波速大于竖向波速,与颗粒长轴分布对波速的影响程度大于接触法向有关;在水平向应力不变的不等向固结应力条件下,竖向波速随竖向与水平向应力比的增加而增加,水平向波速则随应力比增加先保持不变后减小,波速的减小与接触配位数的降低有关。同时,随应力比增加,应力修正后竖向波速与水平向波速的比值先基本不变后逐渐增加并趋近于1.0,这与颗粒长轴及接触法向各向异性的演化有关。

Dual Additives for Stabilizing Li Deposition and SEI Formation in Anode-Free Li-Metal Batteries

Anode-free Li-metal batteries are of significant interest to energy storage industries due to their intrinsically high energy.However,the accumulative Li dendrites and dead Li continuously consume active Li during cycling.That results in a short lifetime and low Coulombic efficiency of anode-free Li-metal batteries.Introducing effective electrolyte additives can improve the Li deposition homogeneity and solid electrolyte interphase(SEI)stability for anode-free Li-metal batteries.Herein,we reveal that introducing dual additives,composed of LiAsF6 and fluoroethylene carbonate,into a low-cost commercial carbonate electrolyte will boost the cycle life and average Coulombic efficiency of NMC‖Cu anode-free Li-metal batteries.The NMC‖Cu anode-free Li-metal batteries with the dual additives exhibit a capacity retention of about 75%after 50 cycles,much higher than those with bare electrolytes(35%).The average Coulombic efficiency of the NMC‖Cu anode-free Li-metal batteries with additives can maintain 98.3%over 100 cycles.In contrast,the average Coulombic efficiency without additives rapidly decline to 97%after only 50 cycles.In situ Raman measurements reveal that the prepared dual additives facilitate denser and smoother Li morphology during Li deposition.The dual additives significantly suppress the Li dendrite growth,enabling stable SEI formation on anode and cathode surfaces.Our results provide a broad view of developing low-cost and high-effective functional electrolytes for high-energy and long-life anode-free Li-metal batteries.

The effect of Laves phases and nano-precipitates on the electrochemical corrosion resistance of Mg-Al-Ca alloys under alkaline conditions

The electrochemical corrosion mechanisms of Mg alloys were extensively studied in previous investigations of different chemical com-positions,modified surface states and various electrolyte conditions.However,recent research focused on the active state of Mg dissolution,leading to unresolved effects of secondary phases adjacent to a stableα-solid solution passive layer.The present study investigates the fundamental electrochemical corrosion mechanisms of three different Laves phases with varying phase morphologies and phase fractions in the passive state of Mg-Al-Ca alloys.The microstructure was characterized by(transmission-)electron microscopy and synchrotron-based transmission X-ray microscopy.The electrochemical corrosion resistance was determined with a standard three-electrode setup and advanced in-situ flow cell measurements.A new electrochemical activity sequence(C15>C36>α-Mg>C14)was obtained,as a result of a stable passive layer formation on theα-solid solution.Furthermore,nm-scale Mg-rich precipitates were identified within the Laves phases,which tend to inhibit the corrosion kinetics.

Closure Effect ofⅠ+ⅡMixed-mode Crack for EA4T Axle Steel

The crack-closure effect is a crucial factor that affects the crack growth rate and should be considered in simulation analysis and testing.A mixed-mode I+II loading fatigue crack growth test was performed using EA4T axle steel specimens.The variation of the plastic-induced crack closure(PICC)effect and the roughness-induced crack closure(RICC)effect during crack deflection in the mixed-mode is examined in this study.The results show that the load perpendicular to the crack propagation direction hinders the slip effect caused by the load parallel to the crack propagation direction under mixed-mode loading,and the crack deflection is an intuitive manifestation of the interaction between the PICC and RICC.The proportion of the RA value change on the crack side caused by contact friction was reduced by the interaction between PICC and RICC.The roughness of the crack surface before and after the crack deflection is different,and the spatial torsion crack surface is formed during the crack propagation process.With the increase of the crack length,the roughness of the fracture surface increases.During the crack deflection process,the PICC value fluctuates around 0.2,and the RICC value is increased to 0.15.

Review on the plastic instability of medium -Mn steels for identifying the formation mechanisms of Lüders and Portevin -Le Chatelier bands

Plastic instability,including both the discontinuous yielding and stress serrations,has been frequently observed during the tensile deformation of medium-Mn steels(MMnS)and has been intensively studied in recent years.Unfortunately,research results are controversial,and no consensus has been achieved regarding the topic.Here,we first summarize all the possible factors that affect the yielding and flow stress serrations in MMnS,including the morphology and stability of austenite,the feature of the phase interface,and the deformation parameters.Then,we propose a universal mechanism to explain the conflicting experimental results.We conclude that the discontinuous yielding can be attributed to the lack of mobile dislocation before deformation and the rapid dislocation multiplication at the beginning of plastic deformation.Meanwhile,the results show that the stress serrations are formed due to the pinning and depinning between dislocations and interstitial atoms in austenite.Strain-induced martensitic transformation,influenced by the mechanical stability of austenite grain and deformation parameters,should not be the intrinsic cause of plastic instability.However,it can intensify or weaken the discontinuous yielding and the stress serrations by affecting the mobility and density of dislocations,as well as the interaction between the interstitial atoms and dislocations in austenite grains.

High temperature deformation and recrystallization behavior of magnesium bicrystals with 90°<1010>and 90°<1120>tilt grain boundaries

The deformation mechanisms and dynamic recrystallization(DRX)behavior of specifically grown bicrystals with a symmetric 90°<1010>and 90°<1120>tilt grain boundary,respectively,were investigated under deformation in plane strain compression at 200℃and 400℃.The microstructures were analyzed by panoramic optical microscopy and large-area electron backscatter diffraction(EBSD)orientation mapping.The analysis employed a meticulous approach utilizing hundreds of individual,small EBSD maps with a small step size that were stitched together to provide comprehensive access to orientation and misorientation data on a macroscopic scale.Basal slip primarily governed the early stages of deformation at the two temperatures,and the resulting shear induced lattice rotation around the transverse direction(TD)of the sample.The existence of the grain boundary gave rise to dislocation pile-up in its vicinity,leading to much larger TD-lattice rotations within the boundary region compared to the bulk.With increasing temperature,the deformation was generally more uniform towards the bulk due to enhanced dislocation mobility and more uniform stress distribution.Dynamic recrystallization at 200℃was initiated in{1011}-compression twins at strains of 40%and higher.At 400℃,DRX consumed the entire grain boundary region and gradually replaced the deformed microstructure with progressing deformation.The recrystallized grains displayed characteristic orientations,such that their c-axes were perpendicular to the TD and additionally scattered between 0°and 60°from the loading axis.These recrystallized grains displayed mutual rotations of up to 30°around the c-axes of the initial grains,forming a discernible basal fiber texture component,prominently visible in the{1120}pole figure.It is noteworthy that the deformation and DRX behaviors of the two analyzed bicrystals exhibited marginal variations in response to strain and deformation temperature.

State-of-health estimation for fast-charging lithium-ion batteries based on a short charge curve using graph convolutional and long short-term memory networks

A fast-charging policy is widely employed to alleviate the inconvenience caused by the extended charging time of electric vehicles. However, fast charging exacerbates battery degradation and shortens battery lifespan. In addition, there is still a lack of tailored health estimations for fast-charging batteries;most existing methods are applicable at lower charging rates. This paper proposes a novel method for estimating the health of lithium-ion batteries, which is tailored for multi-stage constant current-constant voltage fast-charging policies. Initially, short charging segments are extracted by monitoring current switches,followed by deriving voltage sequences using interpolation techniques. Subsequently, a graph generation layer is used to transform the voltage sequence into graphical data. Furthermore, the integration of a graph convolution network with a long short-term memory network enables the extraction of information related to inter-node message transmission, capturing the key local and temporal features during the battery degradation process. Finally, this method is confirmed by utilizing aging data from 185 cells and 81 distinct fast-charging policies. The 4-minute charging duration achieves a balance between high accuracy in estimating battery state of health and low data requirements, with mean absolute errors and root mean square errors of 0.34% and 0.66%, respectively.

Toughening ultrastrong low-density steel by textured δ-ferrite lamellas

By both the Charpy V-notched impact and the projectile tests, we here investigated the dynamic fracture behavior of a recently developed ultrastrong lightweight steel comprising a hierarchical martensitic matrix, dispersed ultra-fine-retained austenite grains and oriented δ-ferrite lamellas, the latter being due to high Al and Si contents employed for low-density design. This steel shows a superior combination of specific ultimate tensile strength and impact toughness to other ultrastrong steels and has successfully arrested a real steel-cored bullet shot. These are attributed to the densely textured δ-ferrite lamellas that can deflect the propagating cracks until they are trapped and enclosed besides austenite-to-martensite transformation crack closure, leading to more energy consumed before failure. These results suggest a new pathway for toughening ultrastrong lightweight steels.

PML nuclear bodies:new players in familial amyotrophic lateral sclerosis-frontotemporal dementia?

Amyotrophi c lateral s c lerosis(ALS)and frontotemporal dementia(FTD)are two closely related disorders with overlapping clinical,genetic,and neuropathological features,forming a continuous disease spectrum(Ling et al.,2013).The major pathological hallmark of ALS and FTD are the depletion from the nucleus of the RNA-binding proteins TAR DNA‐binding protein 43(TDP-43)and FUsed in Sarcoma(FUS)and their abnormal accumulation in ubiquitin-positive cytoplasmic inclusions(Ling et al.,2013).

Low-temperature replacement construction of three-dimensional corrosion-resistant interface for deeply rechargeable Zn metal batteries

Aqueous Zn batteries are promising candidates for grid-scale renewable energy storage.Foil electrodes have been widely investigated and applied as anode materials for aqueous Zn batteries,however,they suffer from limited surface area and severe interfacial issues including metallic dendrites and corrosion side reactions,limiting the depth of discharge(DOD)of the foil electrode materials.Herein,a low-temperature replacement reaction is utilized to in-situ construct a three-dimensional(3D)corrosion-resistant interface for deeply rechargeable Zn foil electrodes.Specifically,the deliberate low-temperature environment controlled the replacement rate between polycrystalline Zn metal and oxalic acid,producing a Zn foil electrode with distinct 3D corrosion-resistant interface(3DCI-Zn),which differed from conventional two-dimensional(2D)protective structure and showed an order of magnitude higher surface area.Consequently,the 3DCI-Zn electrode exhibited dendrite-free and anticorrosion properties,and achieved stable plating/stripping performance for 1000 h at 10 mA cm^(-2)and 10 mAh cm^(-2)with a remarkable DOD of 79%.After pairing with a MnO2cathode with a high areal capacity of 4.2 mAh cm^(-2),the pouch cells delivered 168 Wh L^(-1)and a capacity retention of 89.7%after 100 cycles with a low negative/positive(N/P)ratio of 3:1.

New High-Order Numerical Methods for Hyperbolic Systems of Nonlinear PDEs with Uncertainties

In this paper,we develop new high-order numerical methods for hyperbolic systems of nonlinear partial differential equations(PDEs)with uncertainties.The new approach is realized in the semi-discrete finite-volume framework and is based on fifth-order weighted essentially non-oscillatory(WENO)interpolations in(multidimensional)random space combined with second-order piecewise linear reconstruction in physical space.Compared with spectral approximations in the random space,the presented methods are essentially non-oscillatory as they do not suffer from the Gibbs phenomenon while still achieving high-order accuracy.The new methods are tested on a number of numerical examples for both the Euler equations of gas dynamics and the Saint-Venant system of shallow-water equations.In the latter case,the methods are also proven to be well-balanced and positivity-preserving.

Characterization and quantification of multi-field coupling in lithium-ion batteries under mechanical constraints

The safety and durability of lithium-ion batteries under mechanical constraints depend significantly on electrochemical,thermal,and mechanical fields in applications.Characterizing and quantifying the multi-field coupling behaviors requires interdisciplinary efforts.Here,we design experiments under mechanical constraints and introduce an in-situ analytical framework to clarify the complex interaction mechanisms and coupling degrees among multi-physics fields.The proposed analytical framework integrates the parameterization of equivalent models,in-situ mechanical analysis,and quantitative assessment of coupling behavior.The results indicate that the significant impact of pressure on impedance at low temperatures results from the diffusion-controlled step,enhancing kinetics when external pressure,like 180 to 240 k Pa at 10℃,is applied.The diversity in control steps for the electrochemical reaction accounts for the varying impact of pressure on battery performance across different temperatures.The thermal expansion rate suggests that the swelling force varies by less than 1.60%per unit of elevated temperature during the lithiation process.By introducing a composite metric,we quantify the coupling correlation and intensity between characteristic parameters and physical fields,uncovering the highest coupling degree in electrochemical-thermal fields.These results underscore the potential of analytical approaches in revealing the mechanisms of interaction among multi-fields,with the goal of enhancing battery performance and advancing battery management.

Coactivator-independent vitamin D receptor signaling causes severe rickets in mice,that is not prevented by a diet high in calcium,phosphate,and lactose

The vitamin D receptor(VDR)plays a critical role in the regulation of mineral and bone homeostasis.Upon binding of 1α,25-dihydroxyvitamin D_(3) to the VDR,the activation function 2(AF2)domain repositions and recruits coactivators for the assembly of the transcriptional machinery required for gene transcription.

Recent innovations in laser additive manufacturing of titanium alloys

Titanium(Ti)alloys are widely used in high-tech fields like aerospace and biomedical engineering.Laser additive manufacturing(LAM),as an innovative technology,is the key driver for the development of Ti alloys.Despite the significant advancements in LAM of Ti alloys,there remain challenges that need further research and development efforts.To recap the potential of LAM high-performance Ti alloy,this article systematically reviews LAM Ti alloys with up-to-date information on process,materials,and properties.Several feasible solutions to advance LAM Ti alloys are reviewed,including intelligent process parameters optimization,LAM process innovation with auxiliary fields and novel Ti alloys customization for LAM.The auxiliary energy fields(e.g.thermal,acoustic,mechanical deformation and magnetic fields)can affect the melt pool dynamics and solidification behaviour during LAM of Ti alloys,altering microstructures and mechanical performances.Different kinds of novel Ti alloys customized for LAM,like peritecticα-Ti,eutectoid(α+β)-Ti,hybrid(α+β)-Ti,isomorphousβ-Ti and eutecticβ-Ti alloys are reviewed in detail.Furthermore,machine learning in accelerating the LAM process optimization and new materials development is also outlooked.This review summarizes the material properties and performance envelops and benchmarks the research achievements in LAM of Ti alloys.In addition,the perspectives and further trends in LAM of Ti alloys are also highlighted.

TGF-β1基因多态性与肝炎后肝纤维化的相关性研究

目的:探讨TGF-β1基因多态性与肝炎后肝纤维化的关系。方法:以实时荧光PCR结合熔点曲线分析,建立可高通量检测TGF-β1编码区3个单核苷酸多态性(SNPs)位点的LightCycler方法,这3个位点分别为Leu10Pro(T>C)、Arg25Pro(G>C)、Thr263Ile(C>T),并对亚洲人群中HBV感染导致的肝纤维化患者(90例)及高加索人群中HCV感染导致的肝纤维化患者(210例)进行SNP分析,并分别与104例亚洲人群和50例高加索人群正常献血员进行比较。结果:亚洲人群中病患组与正常对照组TGF-β1编码区第25、263位氨基酸皆无基因多态性,与高加索人群的检测结果有显著差异;而亚洲人群第10位氨基酸基因多态性出现频率相对较高,病患组(T／C=0.444／0.556)较正常对照组(T／C=0.514／0.486)突变频率稍高,但无显著差异。在高加索人群HCV感染导致的肝纤维化患者中第10、25位氨基酸基因多态性出现的频率与肝纤维化发展程度(average METAVIR-Score)密切相关。结论:提示TGF-β1基因多态性与高加索人群肝炎后肝纤维化的发生具有重要相关性;与亚洲人群肝炎后肝纤维化发生的相关性有待进一步研究。

煤及显微组分在超高温开放体系实验中动力学参数确立与天然气形成过程预测

通过对塔里木盆地煤及其显微组分以1K/min升温速率在开放体系下进行热模拟实验(Tmax=1200℃),确定了CH4与N2生成动力学参数。根据化学反应动力学原理,当煤岩生成CH4和N2为25个一级平行反应且具有相同频率因子(Ao=1.0×1013s-1)时,生成CH4与N2每个反应对应的活化能可以通过实验数据与理论计算拟合,获得Gaussian型活化能分布特征为:CH4在活化能为42～90kcal/mol内,煤、镜质组、壳质组、丝质组和半丝质组生成CH4的主频活化能分别为60、52、50、70和66kcal/mol;N2在活化能为60～108kcal/mol内,其主频活化能分别为74、108、100、108和102kcal/mol。根据这些实验动力学参数,推测了煤岩在地质升温速率为5.3K/Ma时CH4的转化率:CH4在地质温度为20℃时开始形成;当地质温度为160℃时,煤岩中CH4已生成总量的80%。镜质组和壳质组CH4转化率要高于煤岩。

等轴球晶凝固多相体系内热溶质对流、补缩流及晶粒运动的数值模拟 Ⅰ．三相流模型

基于Eulerian-Eulerian方法和体积元平均技术,建立了模拟等轴球晶凝固过程的液、固、气三相流模型．液、固两相处理成相互分离、相互扩散的介质,气相与液、固两相只存在热量及动量的相互作用,三相(凝固前)作为自由流体共享一个统一的压力场．分别求解三相的质量、动量、溶质、热焓守恒方程;相间的热量交换和摩擦拖拽以及液／固界面上的溶质再分配和凝固潜热释放,通过定义对应守恒方程的源项和交换项而加以考虑;另外,单独求解一个晶粒密度守恒方程．晶粒的形核生长(相变) 也加以模型化并体现在对应的源项中,模型中所用的密度定义为溶质与温度的函数,因此可综合考虑热溶质对流、晶粒运动及凝固收缩所引起的补缩流动．凝固过程的体积收缩及补缩流动将体现在气／液自由表面的波动上．

塔里木盆地煤及其显微组分超高温开放体系热模拟实验气态产物对比研究

通过对塔里木盆地煤及其显微组分进行以1K/min升温速率的开放体系热模拟实验(最高实验温度为1200℃),获得了煤岩与各显微组分气态产物产率与累计产量变化。对比分析了煤及其显微组分生成气态产物CH4、N2和CO变化特征,其中N2生成温度高于CH4和CO;H2生成时间与CH4相一致(说明了氢为烃类气体形成的关键因素)。煤及其显微组分生烃潜力具有壳质组>镜质组>煤>半丝质组≥丝质组的特征,说明煤岩生烃潜力主要由其显微组分控制;虽然壳质组在煤岩中含量很低,但生烃潜力高于其他显微组分。煤岩生成的N2具有双峰型特征,说明了前后峰N2具有不同来源,前者来源于无机矿物(如含铵粘土)的分解,后者来源于有机质热降解;显微组分生成N2主要为高温阶段,说明了显微组分在分离过程中可能造成部分无机矿物的损失。