A Distributed Particle Filter Applied in Single Object Tracking

Visual object-tracking is a fundamental task applied in many applications of computer vision. Particle filter is one of the techniques which has been widely used in object tracking. Due to the virtue of extendability and flexibility on both linear and non-linear environments, various particle filter-based trackers have been proposed in the literature. However, the conventional approach cannot handle very large videos efficiently in the current data intensive information age. In this work, a parallelized particle filter is provided in a distributed framework provided by the Hadoop/Map-Reduce infrastructure to tackle object-tracking tasks. The experiments indicate that the proposed algorithm has a better convergence and accuracy as compared to the traditional particle filter. The computational power and the scalability of the proposed particle filter in single object tracking have been enhanced as well.

Review on laser directed energy deposited aluminum alloys

Lightweight aluminum(Al)alloys have been widely used in frontier fields like aerospace and automotive industries,which attracts great interest in additive manufacturing(AM)to process high-value Al parts.As a mainstream AM technique,laser-directed energy deposition(LDED)shows good scalability to meet the requirements for large-format component manufacturing and repair.However,LDED Al alloys are highly challenging due to their inherent poor printability(e.g.low laser absorption,high oxidation sensitivity and cracking tendency).To further promote the development of LDED high-performance Al alloys,this review offers a deep understanding of the challenges and strategies to improve printability in LDED Al alloys.The porosity,cracking,distortion,inclusions,element evaporation and resultant inferior mechanical properties(worse than laser powder bed fusion)are the key challenges in LDED Al alloys.Processing parameter optimizations,in-situ alloy design,reinforcing particle addition and field assistance are the efficient approaches to improving the printability and performance of LDED Al alloys.The underlying correlations between processes,alloy innovation,characteristic microstructures,and achievable performances in LDED Al alloys are discussed.The benchmark mechanical properties and primary strengthening mechanism of LDED Al alloys are summarized.This review aims to provide a critical and in-depth evaluation of current progress in LDED Al alloys.Future opportunities and perspectives in LDED high-performance Al alloys are also outlined.

In-situ additive manufacturing of high strength yet ductility titanium composites with gradient layered structure using N_(2)

It has always been challenging work to reconcile the contradiction between the strength and plasticity of titanium materials.Laser powder bed fusion(LPBF) is a convenient method to fabricate innovative composites including those inspired by gradient layered materials.In this work,we used LPBF to selectively prepare Ti N/Ti gradient layered structure(GLSTi)composites by using different N_(2)–Ar ratios during the LPBF process.We systematically investigated the mechanisms of in-situ synthesis Ti N,high strength and ductility of GLSTi composites using microscopic analysis,TEM characterization,and tensile testing with digital image correlation.Besides,a digital correspondence was established between the N_(2) concentration and the volume fraction of LPBF in-situ synthesized Ti N.Our results show that the GLSTi composites exhibit superior mechanical properties compared to pure titanium fabricated by LPBF under pure Ar.Specifically,the tensile strength of GLSTi was more than 1.5times higher than that of LPBF-formed pure titanium,reaching up to 1100 MPa,while maintaining a high elongation at fracture of 17%.GLSTi breaks the bottleneck of high strength but low ductility exhibited by conventional nanoceramic particle-strengthened titanium matrix composites,and the hetero-deformation induced strengthening effect formed by the Ti N/Ti layered structure explained its strength-plasticity balanced principle.The microhardness exhibits a jagged variation of the relatively low hardness of 245 HV0.2 for the pure titanium layer and a high hardness of 408 HV0.2 for the N_(2) in-situ synthesis layer.Our study provides a new concept for the structure-performance digital customization of 3D-printed Ti-based composites.

Analysis of quality-related proteins in golden pompano(Trachinotus ovatus)fillets with modified atmosphere packaging under superchilling storage

Here,we aimed to study the changes in proteome of golden pompano fillets during post-mortem storage.Tandem mass tags(TMT)-labeled quantitative proteomic strategy was applied to investigate the relationships between protein changes and quality characteristics of modified atmosphere packaging(MAP)fillets during superchilling(-3°C)storage.Scanning electron microscopy was used to show that the muscle histology microstructure of fillets was damaged to varying degrees,and low-field nuclear magnetic resonance was used to find that the immobilized water and free water in the muscle of fillets changed significantly.Total sulfhydryl content,TCA-soluble peptides and Ca2+-ATPase activity also showed that the fillet protein had a deterioration by oxidation and denaturation.The Fresh(FS),MAP,and air packaging(AP)groups were set.Total of 150 proteins were identified as differential abundant proteins(DAPs)in MAP/FS,while 209 DAPs were in AP/FS group.The KEGG pathway analysis indicated that most DAPs were involved in binding proteins and protein turnover.Correlation analysis found that 52 DAPs were correlated with quality traits.Among them,8 highly correlated DAPs are expected to be used as potential quality markers for protein oxidation and water-holding capacity.These results provide a further understanding of the muscle deterioration mechanism of packaging golden pompano fillets during superchilling.

Alanine aminotransferase as a risk marker for new-onset metabolic dysfunction-associated fatty liver disease

In this editorial,we comment on the article by Chen et al.Metabolic dysfunction-associated fatty liver disease(MAFLD)is a global public health burden whose incidence has risen concurrently with overweight and obesity.Given its detri-mental health impact,early identification of at-risk individuals is crucial.MAFLD diagnosis is based on evidence of hepatic steatosis indicated by liver biopsy,imaging,or blood biomarkers,and one of the following conditions:Overweight/obesity,type 2 diabetes mellitus,or metabolic dysregulation.However,in large-scale epidemiological studies,liver biopsies are not feasible.The application of techniques such as ultrasonography,computed tomography,magnetic resonance imaging,and magnetic resonance spectroscopy is restricted by their limited sensitivity,low effectiveness,high costs,and need for specialized software.Blood biomarkers offer several advantages,particularly in large-scale epidemiological studies or clinical scenarios where traditional imaging techniques are impractical.Analysis of cumulative effects of excess high-normal blood alanine aminotrans-ferase(ALT)levels of blood ALT levels could facilitate identification of at-risk patients who might not be detected through conventional imaging methods.Accordingly,investigating the utility of blood biomarkers in MAFLD should enhance early detection and monitoring,enabling timely inter-vention and management and improving patient outcomes.

Influence of High-Density Bedding Plane Characteristics on Hydraulic Fracture Propagation in Shale Oil Reservoir

The existence of high-density bedding planes is a typical characteristic of shale oil reservoirs.Understanding the behavior of hydraulic fracturing in high-density laminated rocks is significant for promoting shale oil production.In this study,a hydraulic fracturing model considering tensile failure and frictional slip of the bedding planes is established within the framework of the unified pipe-interface element method(UP-IEM).The model developed for simulating the interaction between the hydraulic fracture and the bedding plane is validated by comparison with experimental results.The hydraulic fracturing patterns in sealed and unsealed bedding planes are compared.Additionally,the effects of differential stress,bedding plane permeability,spacing,and the friction coefficient of the bedding plane are investigated.The results showed that a single main fracture crossing the bedding planes is more likely to form in sealed bedding planes under high differential stress.The decrease in bedding plane permeability and the increase in the friction coefficient also promote the fracture propagating perpendicular to the bedding planes.Shale with high-density bedding planes has a poorer fracturing effect than that with low-density bedding planes,as the hydraulic fracture is prone to initiate and propagate along the bedding planes.Moreover,higher injection pressure is needed to maintain fracture propagation along the bedding.An increase in bedding density will lead to a smaller fracturing area.Fracturing fluid seepage into the bedding planes slows shale fracturing.It is recommended that increasing the injection flow rate,selecting alternative fracturing fluids,and employing multi-well/multi-cluster fracturing may be efficient methods to improve energy production in shale oil reservoirs.

Simplified liver imaging reporting and data system for the diagnosis of hepatocellular carcinoma on gadoxetic acid-enhanced magnetic resonance imaging

BACKGROUND The liver imaging reporting and data system(LI-RADS)diagnostic table has 15 cells and is too complex.The diagnostic performance of LI-RADS for hepatocellular carcinoma(HCC)is not satisfactory on gadoxetic acid-enhanced magnetic resonance imaging(EOB-MRI).AIM To evaluate the ability of the simplified LI-RADS(sLI-RADS)to diagnose HCC on EOB-MRI.METHODS A total of 331 patients with 356 hepatic observations were retrospectively analysed.The diagnostic performance of sLI-RADS A-D using a single threshold was evaluated and compared with LI-RADS v2018 to determine the optimal sLIRADS.The algorithms of sLI-RADS A-D are as follows:The single threshold for sLI-RADS A and B was 10 mm,that is,classified observations≥10mm using an algorithm of 10-19 mm observations(sLI-RADS A)and≥20 mm observations(sLI-RADS B)in the diagnosis table of LI-RADS v2018,respectively,while the classification algorithm remained unchanged for observations<10 mm;the single threshold for sLI-RADS C and D was 20 mm,that is,for<20 mm observations,the algorithms for<10 mm observations(sLI-RADS C)and 10-19 mm observations(sLI-RADS D)were used,respectively,while the algorithm remained unchanged for observations≥20 mm.With hepatobiliary phase(HBP)hypointensity as a major feature(MF),the final sLI-RADS(F-sLI-RADS)was formed according to the optimal sLI-RADS,and its diagnostic performance was evaluated.The times needed to classify the observations according to F-sLIRADS and LI-RADS v2018 were compared.RESULTS The optimal sLI-RADS was sLI-RADS D(with a single threshold of 20 mm),because its sensitivity was greater than that of LI-RADS v2018(89.8%vs 87.0%,P=0.031),and its specificity was not lower(89.4%vs 90.1%,P>0.999).With HBP hypointensity as an MF,the sensitivity of F-sLI-RADS was greater than that of LI-RADS v2018(93.0%vs 87.0%,P<0.001)and sLI-RADS D(93.0%vs 89.8%,P=0.016),without a lower specificity(86.5%vs 90.1%,P=0.062;86.5%vs 89.4%,P=0.125).Compared with that of LI-RADS v2018,the time to classify lesions according to FsLI-RADS was shorter(51±21 s vs 73±24 s,P<0.001).CONCLUSION The use of sLI-RADS with HBP hypointensity as an MF may improve the sensitivity of HCC diagnosis and reduce lesion classification time.

Self-Catalyzed Rechargeable Lithium-Air Battery by in situ Metal Ion Doping of Discharge Products: A Combined Theoretical and Experimental Study

Lithium-air battery has emerged as a viable electrochemical energy technology;yet a substantial overpotential is typically observed,due to the insulating nature of the discharge product Li_(2)O_(2) that hinders the reaction kinetics and device performance.Furthermore,finite solid–solid/-liquid interfaces are formed between Li_(2)O_(2) and catalysts and limit the activity of the electrocatalysts in battery reactions,leading to inadequate electrolytic efficiency.Herein,in-situ doping of Li_(2)O_(2) by select metal ions is found to significantly enhance the lithium-air battery performance,and Co^(2+)stands out as the most effective dopant among the series.This is ascribed to the unique catalytic activity of the resulting Co-O_(x) sites towards oxygen electrocatalysis,rendering the lithium-air battery self-catalytically active.Theoretical studies based on density functional theory calculations show that structural compression occurs upon Co^(2+)doping,which lowers the energy barrier of Li_(2)O_(2) decomposition.Results from this study highlight the significance of in situ electrochemical doping of the discharge product in enhancing the performance of lithium-air battery.

Integral imaging-based tabletop light field 3D display with large viewing angle

Light field 3D display technology is considered a revolutionary technology to address the critical visual fatigue issues in the existing 3D displays.Tabletop light field 3D display provides a brand-new display form that satisfies multi-user shared viewing and collaborative works,and it is poised to become a potential alternative to the traditional wall and portable display forms.However,a large radial viewing angle and correct radial perspective and parallax are still out of reach for most current tabletop light field 3D displays due to the limited amount of spatial information.To address the viewing angle and perspective issues,a novel integral imaging-based tabletop light field 3D display with a simple flat-panel structure is proposed and developed by applying a compound lens array,two spliced 8K liquid crystal display panels,and a light shaping diffuser screen.The compound lens array is designed to be composed of multiple three-piece compound lens units by employing a reverse design scheme,which greatly extends the radial viewing angle in the case of a limited amount of spatial information and balances other important 3D display parameters.The proposed display has a radial viewing angle of 68.7°in a large display size of 43.5 inches,which is larger than the conventional tabletop light field 3D displays.The radial perspective and parallax are correct,and high-resolution 3D images can be reproduced in large radial viewing positions.We envision that this proposed display opens up possibility for redefining the display forms of consumer electronics.

Proton induced radiation effect of SiC MOSFET under different bias

Radiation effects of silicon carbide metal–oxide–semiconductor field-effect transistors(SiC MOSFETs)induced by 20 MeV proton under drain bias(V_(D)=800 V,V_(G)=0 V),gate bias(V_(D)=0 V,V_(G)=10 V),turn-on bias(V_(D)=0.5 V,V_(G)=4 V)and static bias(V_(D)=0 V,V_(G)=0 V)are investigated.The drain current of SiC MOSFET under turn-on bias increases linearly with the increase of proton fluence during the proton irradiation.When the cumulative proton fluence reaches 2×10^(11)p·cm^(-2),the threshold voltage of SiC MOSFETs with four bias conditions shifts to the left,and the degradation of electrical characteristics of SiC MOSFETs with gate bias is the most serious.In the deep level transient spectrum test,it is found that the defect energy level of SiC MOSFET is mainly the ON2(E_(c)-1.1 eV)defect center,and the defect concentration and defect capture cross section of SiC MOSFET with proton radiation under gate bias increase most.By comparing the degradation of SiC MOSFET under proton cumulative irradiation,equivalent 1 MeV neutron irradiation and gamma irradiation,and combining with the defect change of SiC MOSFET under gamma irradiation and the non-ionizing energy loss induced by equivalent 1 MeV neutron in SiC MOSFET,the degradation of SiC MOSFET induced by proton is mainly caused by ionizing radiation damage.The results of TCAD analysis show that the ionizing radiation damage of SiC MOSFET is affected by the intensity and direction of the electric field in the oxide layer and epitaxial layer.

Neuroprotective effects of curculigoside against Alzheimer’s disease via regulation oxidative stress mediated mitochondrial dysfunction in L-Glu-exposed HT22 cells and APP/PS1 mice

Curculigoside(CCG)is a phenolic glycoside compound extracted from the root of a natural plant called Curculigo orchioides Gaertn.In this study,the neuroprotective effect of CCG through oxidative stress mediated mitochondrial dysfunction on L-glutamate(L-Glu)-damaged hippocampal neuron cell line(HT22)and APPswe/PSEN1dE9 transgenic(APP/PS1)mice were investigated.Observably,CCG in L-Glu-damaged HT22 cells suppressed apoptosis,reduced the accumulation of reactive oxygen species,balanced the mitochondrial membrane potential and prevented the over-influx of calcium.In APP/PS1 mice,4-week CCG administration significantly improved their memory and behavioral impairments,enhanced the function of cholinergic system,reduced the deposition of Aβand neurofibrillary fiber tangles caused by tau phosphorylation,and suppressed the development and progression of oxidative stress in brains of APP/PS1 mice.Based on the screening of proteomic analysis on hippocampus,CCG were confirmed that it could regulate the expression levels of proteins related to mitochondrial dysfunction,mainly through activating on AMPK/Nrf2 signaling,in APP/PS1 mice and L-Glu-exposed HT22 cells.CCG has a prominent neuroprotective effect on regulate the AMPK/Nrf2-mediated mitochondrial dysfunction in cells APP/PS1 mice support CCG is a potentially potent drug for AD treatment and merits further investigation.

Single Image Desnow Based on Vision Transformer and Conditional Generative Adversarial Network for Internet of Vehicles

With the increasing popularity of artificial intelligence applications,machine learning is also playing an increasingly important role in the Internet of Things(IoT)and the Internet of Vehicles(IoV).As an essential part of the IoV,smart transportation relies heavily on information obtained from images.However,inclement weather,such as snowy weather,negatively impacts the process and can hinder the regular operation of imaging equipment and the acquisition of conventional image information.Not only that,but the snow also makes intelligent transportation systems make the wrong judgment of road conditions and the entire system of the Internet of Vehicles adverse.This paper describes the single image snowremoval task and the use of a vision transformer to generate adversarial networks.The residual structure is used in the algorithm,and the Transformer structure is used in the network structure of the generator in the generative adversarial networks,which improves the accuracy of the snow removal task.Moreover,the vision transformer has good scalability and versatility for larger models and has a more vital fitting ability than the previously popular convolutional neural networks.The Snow100K dataset is used for training,testing and comparison,and the peak signal-to-noise ratio and structural similarity are used as evaluation indicators.The experimental results show that the improved snow removal algorithm performs well and can obtain high-quality snow removal images.

Effects of resistant starchⅢon the serum lipids levels and gut microbiota of Kunming mice under high-fat diet

Resistant starch III(RS3),as a prebiotic,provides health benefits.This study aimed to investigate the role of RS3 in lowering serum lipids and regulating gut microbiota by administering Novelose 330 to Kunming(KM)mice.The results demonstrated that RS3 intervention significantly decreased body weight,food intake,levels of serum total cholesterol(TC),triglyceride(TG),low-density lipoprotein cholesterol(LDL-C),and liver fat.RS3 could remarkably improve the quality of the entire cecum,quality of the cecal wall,and wall surface area of mice;enhance the moisture content;and reduce the p H value.Moreover,the decrease in the liver TC content and the increase in the fecal TC content were related to RS3 intervention.The concentrations of total short-chain fatty acids(SCFAs)in the colon and individual levels of acetate,propionate,and butyrate increased with RS3 supplementation.An Illumina-based sequencing approach showed that RS3 notably increased the Bacteroides/Firmicutes ratio in the mice fed a high-fat diet.At the genus level,the relative abundance of Bacteroides,Ruminococcus,and Bifidobacterium and the number of main SCFA producers increased in the mice fed an RS3 diet.These findings provided insights into specific gut microbiota shifts to the hypolipidemic effect of RS3.

Effect of modified MgAl-LDH coating on corrosion resistance and friction properties of aluminum alloy

The in-situ growing approach was utilized in this article to construct the magnesium–aluminum layered double hydroxide(MgAl-LDH)film on the surface of a 1060 aluminum anodized film.To improve the corrosion resistance and friction qualities of aluminum alloy,the MgAl-LDH coating was treated using stearic acid(SA)and thiourea(TU).The aluminum substrate and anodized aluminum film layer corroded to varying degrees after 24 h of immersion in 3.5%(mass)NaCl solution,while the modified hydrotalcite film layer continued to exhibit the same microscopic morphology even after being immersed for 7 d.The results show that the synergistic action of thiourea and stearic acid can effectively improve the corrosion resistance of the MgAl-LDH substrate.The tribological testing reveals that the hydrotalcite film layer and the modified film layer lowered the friction coefficient of the anodized aluminum surface substantially.The results of the simulations and experiments demonstrate that SA forms the dense LDH-TU interlayer film layer by exchanging NO_(3)^(-)ions between TU layers on the one hand and the LDH-SA film layer by adsorption on the surface of LDH on the other.Together,these two processes create LDH-TUSA,which can significantly increase the substrate’s corrosion resistance.This synergistically modified superhydrophobic and retardant hydrotalcite film layer offers a novel approach to the investigation of wear reduction and corrosion protection on the surface of aluminum and its alloys.

Isoforsythiaside confers neuroprotection against Alzheimer's disease by attenuating ferroptosis and neuroinflammation in vivo and in vitro

Ferroptosis and neuroinflammation contribute to the development of Alzheimer's disease(AD). Isoforsythiaside(IFY)is a phenylethanoid glycoside isolated from the dried fruit of Forsythia suspensa(Thunb.)Vahl that has been confirmed to improve the memory and cognitive abilities of APP/PS1 mice in our previous study. The purpose of this study was to explore the anti-ferroptosis and anti-neuroinflammatory properties of IFY-mediated neuroprotection. In APP/PS1 mice, erastin-damaged HT22 cells, and LPS-exposed BV2 cells, the neuroprotective effects against ferroptosis and neuroinflammation were investigated using immunohistochemistry, label-free proteomics, western blot, ELISA, MTT, fluorescence, and TEM. IFY alleviated the expression levels of NO, IL-6, and IL-1β in LPS-exposed BV2 cells and improved the morphology of mitochondria in erastin-damaged HT22 cells. Additionally, IFY upregulated the expression levels of GPX4, FTH, FTL, p-GSK-3β, Nrf2, and NQO1, and downregulated the expression of TFR1, DMT1, p-Fyn, GFAP, p-IKKα+β, p-IκBα, p-NF-κB, and pro-inflammatory factors in the brains of APP/PS1 mice and erastin-damaged HT22 cells. In conclusion, IFY inhibits ferroptosis and neuroinflammation in erastin-damaged HT22 cells and APP/PS1 mice, at least partially by regulating the activation of Nrf2 and NF-κB signaling. IFY may prevent ferroptosis and neuroinflammation in AD and provide a new treatment strategy for AD.

Sensory nerves directly promote osteoclastogenesis by secreting peptidyl-prolyl cis-trans isomerase D(Cyp40)

Given afferent functions,sensory nerves have recently been found to exert efferent effects and directly alter organ physiology.Additionally,several studies have highlighted the indirect but crucial role of sensory nerves in the regulation of the physiological function of osteoclasts.Nonetheless,evidence regarding the direct sensory nerve efferent influence on osteoclasts is lacking.In the current study,we found that high levels of efferent signals were transported directly from the sensory nerves into osteoclasts.Furthermore,sensory hypersensitivity significantly increased osteoclastic bone resorption,and sensory neurons(SNs)directly promoted osteoclastogenesis in an in vitro coculture system.Moreover,we screened a novel neuropeptide,Cyp40,using an isobaric tag for relative and absolute quantitation(iTRAQ).We observed that Cyp40 is the efferent signal from sensory nerves,and it plays a critical role in osteoclastogenesis via the aryl hydrocarbon receptor(AhR)-Ras/Raf-p-Erk-NFATc1 pathway.These findings revealed a novel mechanism regarding the influence of sensory nerves on bone regulation,i.e.,a direct promoting effect on osteoclastogenesis by the secretion of Cyp40.Therefore,inhibiting Cyp40 could serve as a strategy to improve bone quality in osteoporosis and promote bone repair after bone injury.

Amide proton transfer imaging of Alzheimer's disease and Parkinson's disease

Amide proton transfer (APT) magnetic resonance imaging (MRI) is an important molecularimaging technique at the protein level in tissue. Neurodegenerative diseases have a highlikelihood of causing abnormal protein accumulation in the brain, which can be detectedby APT MRI. This article briefly introduces the principles and image processing technologyof APT MRI, and reviews the current state of research on Alzheimer's disease and Parkinson's disease using this technique. Early applications of this approach in these twoneurodegenerative diseases are encouraging, which also suggests continued technicaldevelopment and larger clinical trials to gauge the value of this technique.

Evaluation of Magnetic Resonance Imaging Findings and Short-Term Outcome in Brain Metastatic Tumors after CyberKnife Treatment

Objective: To evaluate the treatments’ outcomes in brain metastatic tumors after CyberKnife treatment according to magnetic resonance imaging (MRI) findings and improvement of symptoms. Methods: A retrospective analysis of CyberKnife treatment;63 cases of patients with brain metastases;the use of CyberKnife treatment;short-term outcome evaluation after treatment and the MRI findings and measured before treatment and underwent diffusion-weighted imaging MRI scan of apparent diffusion coefficient (ADC) values. Results: 3 months after CyberKnife treatment and effectiveness were 82.5% and 96.8% respectively;6 months and one year survival rates were 82.5% and 55.6% respectively;the median survival time was 16 months. MRI of 52 patients (67 lesions) ADC values after treatment increased to some extent than before treatment. There are 38 lesions volume to shrink or disappear, no enhancement or slight enhancement in the lesion, no edema zone;27 lesions does not change in volume, no edema (18 lesions significantly weakened the degree of enhancement;6 lesions showed no obvious change enhancement;3 lesions showed ring enhancement, internal cystic);2 lesions volume were larger, heterogeneous enhancement, peripheral edema. Conclusion: CyberKnife is an effective method for treating brain metastatic tumor. MRI can accurately evaluate tumor lesions after treatment.

Role of heterogenous microstructure and deformation behavior in achieving superior strength-ductility synergy in zinc fabricated via laser powder bed fusion

Zinc(Zn)is considered a promising biodegradable metal for implant applications due to its appropriate degradability and favorable osteogenesis properties.In this work,laser powder bed fusion(LPBF)additive manufacturing was employed to fabricate pure Zn with a heterogeneous microstructure and exceptional strength-ductility synergy.An optimized processing window of LPBF was established for printing Zn samples with relative densities greater than 99%using a laser power range of 80∼90 W and a scanning speed of 900 mm s−1.The Zn sample printed with a power of 80 W at a speed of 900 mm s−1 exhibited a hierarchical heterogeneous microstructure consisting of millimeter-scale molten pool boundaries,micrometer-scale bimodal grains,and nanometer-scale pre-existing dislocations,due to rapid cooling rates and significant thermal gradients formed in the molten pools.The printed sample exhibited the highest ductility of∼12.1%among all reported LPBF-printed pure Zn to date with appreciable ultimate tensile strength(∼128.7 MPa).Such superior strength-ductility synergy can be attributed to the presence of multiple deformation mechanisms that are primarily governed by heterogeneous deformation-induced hardening resulting from the alternative arrangement of bimodal Zn grains with pre-existing dislocations.Additionally,continuous strain hardening was facilitated through the interactions between deformation twins,grains and dislocations as strain accumulated,further contributing to the superior strength-ductility synergy.These findings provide valuable insights into the deformation behavior and mechanisms underlying exceptional mechanical properties of LPBF-printed Zn and its alloys for implant applications.

Hierarchical CoFe@N-Doped Carbon Decorated Wood Carbon as Bifunctional Cathode in Wearable Zn-Air Battery

Rechargeable Zn-air batteries(ZAB)have drawn extensive attention due to their eco-friendliness and safety.However,the lack of high-performance and low-cost oxygen redox reactions(OER and ORR)catalysts has become one of the main stumbling blocks in their development.Herein,we successfully fabricate a CoFe nanobubble encapsulated in nitrogen-doped carbon nanocage on wood carbon support(CoFe@NC/WC)via pyrolysis of a novel Prussian blue analog(PBA)/spruce precursor.The hierarchical CoFe@NC/WC catalyst exhibits an excellent potential difference of 0.74 V between the OER potential at 10 mA cm^(-2)and half-wave potential of ORR in 0.1 M KOH,comparable to recently reported preeminent electrocatalysts.Further,CoFe@NC/WC shows outstanding electrochemical performance in liquid ZAB,with a peak power density of 138.9 mW cm^(-2)and a specific capacity of 763.5 mAh g^(-1).More importantly,a bacterial cellulose nanofiber reinforced polyacrylic acid(BC-PAA)hydrogel electrolyte shows ultrahigh tensile-breaking stress of 1.58 MPa.In conjunction with the as-prepared CoFe@NC/WC catalyst,BC-PAA-based wearable ZAB displays impressive rechargeability and foldability,and can power portable electronics,such as electronic timer and mobile phone,in bent states.This work provides a new approach toward high-activity and low-cost catalysts for ZAB.