Rechargeable sodium/potassium‐ion batteries (SIBs/PIBs) with abundant reserves of Na/K and low cost have been a promising substitution to commercial lithium‐ion batteries. As for pivotal anode ...materials, metal sulfides (MSx) exhibit an inspiring potential due to the multitudinous redox storage mechanisms for SIBs/PIBs applications. Nevertheless, they still confront several bottlenecks, such as the low electrical conductivity, poor ionic diffusivity, sluggish interfacial/surface reaction kinetics, and severe volume expansion, which distinctly restrain the battery performance. Meanwhile, the systematic insights into the design strategies of MSx for SIBs/PIBs have been seldom elaborated. In this review, the energy storage mechanism, challenge, and design strategies of MSx for SIBs/PIBs are expounded to address the above predicaments. In particular, design strategies of MSx are highlighted from the aspects of morphology modifications involving 1D/2D/3D configurations, atomic‐level engineering containing heteroatom doping, vacancy creation, and interlayer spacing expansion, and MSx composites with other MSx, metal oxides, carbonaceous, and graphite materials to boost the comprehensive electrochemical performance of SIBs/PIBs. Furthermore, prospects are presented for the further advance of MSx to surmount imminent challenges, hoping to forecast feasible future orientations in this field.
Design strategies of metal sulfides are proposed from the aspects of morphology modifications involving 1D/2D/3D configurations, atomic‐level engineering containing heteroatom doping, vacancy creation, and interlayer spacing expansion, and MSx composites with other MSx, metal oxides, carbonaceous and graphite materials to boost the comprehensive electrochemical performance of sodium/potassium‐ion batteries.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Redox‐active organics are investigation hotspots for metal ion storage due to their structural diversity and redox reversibility. However, they are plagued by limited storage capacity, sluggish ion ...diffusion kinetics, and weak structural stability, especially for K+ ion storage. Herein, we firstly reported the lamellar tetrapotassium pyromellitic (K4PM) with four active sites and large interlayer distance for K+ ion storage based on a design strategy, where organics are constructed with the small molecular mass, multiple active sites, fast ion diffusion channels, and rigid conjugated π bonds. The K4PM electrode delivers a high capacity up to 292 mAh g−1 at 50 mA g−1, among the best reported organics for K+ ion storage. Especially, it achieves an excellent rate capacity and long‐term cycling stability with a capacity retention of ≈83 % after 1000 cycles. Incorporating in situ and ex‐situ techniques, the K+ ion storage mechanism is revealed, where conjugated carboxyls are reversibly rearranged into enolates to stably store K+ ions. This work sheds light on the rational design and optimization of organic electrodes for efficient metal ion storage.
The lamellar tetrapotassium pyromellitic (K4PM) for a K‐organic battery delivers a high capacity and excellent cycling robustness due to its four K+ ion storage sites and large layer distance with reversible rearrangement of conjugated carboxyls into enolates.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Laser shock peening is one of the most effective surface strengthening techniques, which uses laser shock-induced plastic deformation to optimize surface stress state and microstructures of target ...material. In this paper, dislocation dynamics simulation was used to investigate laser shock induced ultra-high strain rate plastic deformation of face-centered cubic (FCC) nickel and body-centered cubic (BCC) iron. Molecular dynamics was employed to calculate dislocation mobility. Based on the obtained dislocation mobility coefficient, dislocation dynamics models of nickel and iron were established. Results show that the velocity of dislocation motion increases as temperature decreases. Under ultra-high strain rate deformation, dislocation density of nickel increases while dislocation density of iron decreases as temperature rises. Moreover, iron exhibits thermal softening while nickel exhibits thermal hardening under laser shock loading. Plastic deformation dominated by dislocations is sensitive to loading direction, depending on the Schmidt factor of the slip system. The ultra-high strain rate induced by laser shock can effectively increase dislocation density by promoting dislocation multiplication and suppressing dislocation annihilation.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, SIK, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
•LSP improves the fatigue property of Ti-6Al-4V alloy after FOD.•The improvement of fatigue property is strengthened by TSLSP-I.•TSLSP-I makes a “soft and hard” alternating energy absorption ...structure.
Two-sided and simultaneous laser shock peening (TSLSP) was used to strengthen the Ti-6Al-4V titanium alloy. The fatigue crack growth rate of the specimens was investigated by fatigue test. The results show that both direct TSLSP (TSLSP-D) and indirect TSLSP (TSLSP-I) can reduce the fatigue crack growth rate by producing high magnitude compressive residual stress. The maximum fatigue life increases by 94% (TSLSP-D) and 169% (TSLSP-I) compared with the original specimens. Moreover, the TSLSP-D results show decreased resistance to foreign object damage because of decreased plasticity while the TSLSP-I simultaneously achieves superior foreign object damage resistance and fatigue performance.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
•The functional gradient from primary to transmodal networks was disrupted in ARHL.•The DMN and VN may play a key role in auditory brain associated with cognition.•The aberrant gradient among triple ...networks was linked to cognitive decline in ARHL.
Age-related hearing loss (ARHL), one of the most common sensory deficits in elderly individuals, is a risk factor for dementia; however, it is unclear how ARHL affects the decline in cognitive function. To address this issue, a connectome gradient framework was used to identify critical features of information integration between sensory and cognitive processing centers using resting-state functional magnetic resonance imaging (rs-fMRI) data from 40 individuals with ARHL and 36 healthy controls (HCs). The first three functional gradient alterations associated with ARHL were investigated at the global, network and regional levels. Using a support vector machine (SVM) model, our analysis distinguished individuals with ARHL with normal cognitive function from those with cognitive decline. Compared to HCs, individuals with ARHL had a contracted principal primary-to-transmodal gradient axis, especially in the visual and default mode networks, with an altered gradient explained ratio and variance. Among individuals with ARHL, cognitive decline was detected in the visual network in the principal gradient as well as in the limbic, salience and default mode networks in the third gradient (salience to frontoparietal/default mode). These results suggest that ARHL is associated with disrupted information processing from the primary sensory networks to higher-order cognitive networks and highlight the key nodes closely associated with cognitive decline during cognitive processing in ARHL, providing new insights into the mechanism of cognitive impairment and suggesting potential treatments related to ARHL.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
In this study, a post-treatment method combining annealing and laser shock peening (LSP) is used to tailor the microstructure and mechanical properties of CrMnFeCoNi high-entropy alloy (HEA) prepared ...by laser directed energy deposition (LDED). The microstructure, microhardness, residual stress and tensile property of the as-built, annealed, LSP and annealed + LSP specimens are compared. Results indicate that LSP produces greater plastic deformation on the surface of annealed specimen compared to the pristine as-built specimen, as manifested by a thicker plastically-affected layer. Recrystallization, dislocation network annihilation and thermal stress relaxation caused by annealing contribute to an increase in the plasticity of LDED-prepared specimens, which provides great strengthening conditions for LSP. Gradient strain hardening and compressive residual stress are gained in the surface layer of the annealed specimen subjected to LSP. Moreover, plastic deformation induces a gradient microstructure consisting of ultra-fine grains, high-density mechanical twins and slip bands in order. An excellent strength–ductility synergy is achieved in LDED-prepared CrMnFeCoNi HEA after combined post-treatment of annealing and subsequent LSP.
•Combined post-treatment of annealing and LSP is employed to modify LDED-prepared CrMnFeCoNi HEA.•The microstructural evolution of LDED-prepared CrMnFeCoNi HEA subjected to annealing and LSP in turn is summarized.•An excellent strength–ductility synergy is achieved in LDED-prepared CrMnFeCoNi HEA after combined post-treatment.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Although drilling open holes in fibre metal laminates reduces weight, it brings potential crack initiation sites. This paper investigates the effect of laser shock peening (LSP) on fatigue ...performance of open-hole titanium-based carbon-fibre/epoxy laminates (Ti-CF FMLs). A method based on multi-step simulation was proposed for the reconstruction of LSP induced residual stress field in open-hole Ti-CF FMLs. The results show that the fatigue initiation life of open-hole Ti-CF FMLs is improved by 22.1 %–81.0 % after LSP, depending on the structure of FMLs and the applied fatigue load. The improved fatigue crack initiation life attributes to compressive residual stress generated throughout the entire depth of the hole wall in outer titanium layer in Ti-CF FMLs after LSP. However, LSP leads to the formation of tensile residual stress far from the hole edge, resulting in accelerated propagation of fatigue crack. The fatigue initiation lives of open-hole Ti-CF FMLs before and after LSP were calculated by finite element simulation and theoretical method, showing good consistency.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The neural bases in acute tinnitus remains largely undetected. The objective of this study was to identify the alteration of the brain network involved in patients with acute tinnitus and hearing ...loss.
Acute tinnitus patients (
= 24) with hearing loss and age-, sex-, education-matched healthy controls (
= 21) participated in the current study and underwent resting-state functional magnetic resonance imaging (fMRI) scanning. Regional homogeneity and amplitude of low-frequency fluctuation were used to investigate the local spontaneous neural activity and functional connectivity (FC), and Granger causality analysis (GCA) was used to analyze the undirected and directed connectivity of brain regions.
Compared with healthy subjects, acute tinnitus patients had a general reduction in FC between auditory and non-auditory brain regions. Based on FC analysis, the superior temporal gyrus (STG) revealed reduced undirected connectivity with non-auditory brain regions including the amygdala (AMYG), nucleus accumbens (NAc), the cerebellum, and postcentral gyrus (PoCG). Using the GCA algorithm, increased effective connectivity from the right AMYG to the right STG, and reduced connectivity from the right PoCG to the left NAc was observed in acute tinnitus patients with hearing loss. The pure-tone threshold was positively correlated with FC between the AMYG and STG, and negatively correlated with FC between the left NAc and the right PoCG. In addition, a negative association between the GCA value from the right PoCG to the left NAc and the THI scores was observed.
Acute tinnitus patients have aberrant FC strength and causal connectivity in both the auditory and non-auditory cortex, especially in the STG, AMYG, and NAc. The current findings will provide a new perspective for understanding the neuropathophysiological mechanism in acute tinnitus.
To investigate resting-state connectivity and further understand directional aspects of implicit alterations in presbycusis patients, we used degree centrality (DC) and Granger causality analysis ...(GCA) to detect functional hubs of the whole-brain network and then analyze directional connectivity. Resting-state functional magnetic resonance imaging (fMRI) scans were performed on 40 presbycusis patients and 40 healthy controls matched for age, gender, and education. We used DC analysis and GCA to characterize abnormal brain networks in presbycusis patients. The associations of network centrality and directed functional connectivity (FC) with clinical measures of presbycusis were also examined according to the above results. We found that the network centrality of left frontal middle gyrus (MFG) was significantly lower than that of healthy control group. Unidirectionally, the left MFG revealed increased directional connectivity to the left superior frontal gyrus (SFG), while the left MFG exhibited decreased directional connectivity to the left middle temporal gyrus (MTG) and right lingual gyrus (LinG). And the decreased directional connectivity was found from the left precentral gyrus (PrCG) to the left MFG. In addition, the Trail-Making Test B (TMT-B) score was negatively correlated with the decreased DC of the left MFG (r = −0.359,
p
= 0.032). Resting-state fMRI provides a novel method for identifying aberrant brain network architecture. These results primarily indicate altered functional hubs and abnormal frontal lobe connectivity patterns that may further reflect executive dysfunction in patients with presbycusis.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, VSZLJ, ZAGLJ
Rapid fabricating and harnessing stimuli-responsive behaviors of microscale bio-compatible hydrogels are of great interest to the emerging micro-mechanics, drug delivery, artificial scaffolds, ...nano-robotics, and lab chips. Herein, we demonstrate a novel femtosecond laser additive manufacturing process with smart materials for soft interactive hydrogel micro-machines. Bio-compatible hyaluronic acid methacryloyl was polymerized with hydrophilic diacrylate into an absorbent hydrogel matrix under a tight topological control through a 532 nm green femtosecond laser beam. The proposed hetero-scanning strategy modifies the hierarchical polymeric degrees inside the hydrogel matrix, leading to a controllable surface tension mismatch. Strikingly, these programmable stimuli-responsive matrices mechanized hydrogels into robotic applications at the micro/nanoscale (<300 × 300 × 100 μm
). Reverse high-freedom shape mutations of diversified microstructures were created from simple initial shapes and identified without evident fatigue. We further confirmed the biocompatibility, cell adhesion, and tunable mechanics of the as-prepared hydrogels. Benefiting from the high-efficiency two-photon polymerization (TPP), nanometer feature size (<200 nm), and flexible digitalized modeling technique, many more micro/nanoscale hydrogel robots or machines have become obtainable in respect of future interdisciplinary applications.
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