Black phosphorus(BP)is recognized as a promising anode for sodium-ion batteries(SIBs)due to its high safety and theoretical capacity.However,traditional ball milling methodologies for fabricating BP composite anodes h...Black phosphorus(BP)is recognized as a promising anode for sodium-ion batteries(SIBs)due to its high safety and theoretical capacity.However,traditional ball milling methodologies for fabricating BP composite anodes have not satisfactorily addressed the challenges of poor rate performance and short cycle life.To fill this scientific gap,we herein pioneer incorporating the sodium fast ionic conductorβ"-Al_(2)O_(3)into ball-milled BP with carbon,which facilitates the formation of three-dimensional mass transfer channels in the resulting composite.To stabilize these channels,we develop a novel and environmentally friendly functional binder that outperforms traditional binders in thermal stability,wettability,and mechanical properties.The newly established binder is capable of remarkably mitigating volume expansion and interfacial side reactions in the BP/β"-Al_(2)O_(3)/C composite anode.Additionally,we identify synergistic effects of the binder interacting with the BP/β"-Al_(2)O_(3)/C composite during cycling,characterized by the in-situ formation of P-O-C bonds,which is the first instance of a strong,durable chemical bond between the binder and the active material to the best of our knowledge.These advancements allow the composite electrode to exhibit exceptional sodium storage,including high initial Coulombic efficiency and long-term cycling stability,which surpasses most previous phosphorus-based anodes fabricated via traditional approaches.Notably,when paired with a Na_(4)Fe_(3)(PO_(4))_(2)P_(2)O_7(NFPP)cathode,the full cell exhibits unexpectedly high energy and power densities,highlighting the BP potential in SIBs.The findings presented in the present work contribute to the promotion of economical and efficient applications of phosphorus-based anode materials.展开更多
1.Objective The Songpan-Ganze terrane is a key region for understanding the tectonic evolution of the Tibetan Plateau and the Yangtze Craton.The Songpan-Ganzi complex comprises a thick succession of deformed Ladinian-...1.Objective The Songpan-Ganze terrane is a key region for understanding the tectonic evolution of the Tibetan Plateau and the Yangtze Craton.The Songpan-Ganzi complex comprises a thick succession of deformed Ladinian-Norian turbidites(ca.230-203 Ma),covering about 200000 km^(2)of the eastern Tibet Plateau with a volume of approximately 2.0×10^(6)km^(3)(Fig.1a).Furthermore,this complex has over 100 Permian-Cenozoic felsic plutons.展开更多
Urban rainwater runoff is an important source of nonpoint source pollution due to its transport of diverse contaminants,including polycyclic aromatic hydrocarbons(PAHs)and chlorinated derivatives.Importantly,these chl...Urban rainwater runoff is an important source of nonpoint source pollution due to its transport of diverse contaminants,including polycyclic aromatic hydrocarbons(PAHs)and chlorinated derivatives.Importantly,these chlorinated polycyclic aromatic hydrocarbons(Cl-PAHs)exhibit elevated toxicological potential compared to their non-halogenated parent compounds.In this study,we proposed an approach that combined multivariate receptor model with integration of SHapley Additive exPlanations and Random Forest model.This method identifies the possible sources and reveals the impact of source apportionment results and environmental driving factors(such as geographical and meteorological data)on pollutant concentrations.Sixteen PAHs and nine ClPAHs were detected in 79 runoff samples from all three sites.TheΣ_(16)PAHs average concentration(2923.93 to 6071.83 ng/L)was significantly higher than theΣ_(9)Cl-PAHs(384.34 to 1314.73 ng/L).The source apportionment was conducted by positive matrix factorization(PMF),and six potential pollution sources for PAHs and three for Cl-PAHs were quantified.PAHs primarily originate from the combustion of fossil fuels such as traffic,industrial emissions and coal tar,while Cl-PAHs are mainly derived from atmospheric deposition and industrial emissions.Meanwhile,the self‑organizing map classified PAHs and Cl-PAHs into 2 and 3 groups,respectively.The k-means algorithm yielded 4 clusters for runoff samples.Among machine learning models,Random Forest(RF)demonstrated optimal predictive performance and integrated with SHapley Additive exPlanations(RF-SHAP)revealed the effects of driving factors on the predicted concentration of PAHs and Cl-PAHs in urban runoff samples.展开更多
Background:Repetitive mild traumatic brain injury(rmTBI)is a significant risk factor for neurodegeneration,characterized by pathological protein deposition and persistent neuroinflammation.Research has observed increa...Background:Repetitive mild traumatic brain injury(rmTBI)is a significant risk factor for neurodegeneration,characterized by pathological protein deposition and persistent neuroinflammation.Research has observed increased interleukin-33(IL-33)levels in the peripheral blood of patients with rmTBI,suggesting IL-33 may participate in regulating the pathological development of rmTBI.The study aims to elucidate the impact and mechanism of IL-33 in the progression of neuropathology following rmTBI,and to explore its potential as a therapeutic target to improve the neurological outcome.Methods:The study employed an rmTBI mouse model using the wild-type(WT)and IL-33 knockout mice.Cognitive function was assessed via the Y-maze and Barnes tests.The main cell type expressing IL-33 and its receptor,suppression of tumorigenicity 2(ST2),was then investigated in the mouse brain through immunofluorescence colocalization.As the primary neural cell responsible for ST2 expression,microglia were studied in vitro using the BV2 cell line.The effects of lipid droplets(LDs)accumulation and amyloid-beta(Aβ)phagocytosis were measured to elucidate the impact of IL-33 on BV2 cells'phagocytosis.Additionally,HT22 neuronal apoptosis was assessed by flow cytometry.Finally,the cognitive effects of intranasal administration of IL-33 were evaluated in mice.Results:IL-33 KO mice exhibited pronounced cognitive impairment after rmTBI.In the mouse brain,astrocytes were identified as the primary source of IL-33 secretion,while microglia predominantly expressed ST2.Transcriptome sequencing revealed that IL-33 significantly influenced phagocytosis function.IL-33 mitigated LDs accumulation in BV2 cells and enhanced Aβphagocytosis in vitro.In addition,the culture medium of BV2 cells with activated IL-33/ST2 signaling reduced HT22 neuronal apoptosis and axonal damage.Furthermore,intranasal administration of IL-33 was observed to be effective in alleviating neurodegeneration and cognitive outcome of rmTBI mice.Conclusions:Dysfunction of the IL-33/ST2 axis following rmTBI leads to cognitive dysfunction via impairing microglial phagocytosis capacity and promoting neuronal damage.IL-33 would be a promising therapeutic target for alleviating neurodegeneration following rmTBI.展开更多
The optical tweezer experiment with neutral atoms is widely used for quantum information research.Here,we present a compact dual magneto-optical trap(MOT)setup for a two-species optical tweezer.Rubidium(Rb)atoms are d...The optical tweezer experiment with neutral atoms is widely used for quantum information research.Here,we present a compact dual magneto-optical trap(MOT)setup for a two-species optical tweezer.Rubidium(Rb)atoms are directly captured using a vapor MOT,while potassium(K)atoms are collected via a 2-stage MOT.Both the quadratic and gradient magnetic fields required for the MOT and Zeeman slower are created by permanent magnets.With the help of the Zeeman slower,the K MOT loading efficiency is enhanced by a factor of three.After the MOT stage,we apply D_(1) gray molasses to reduce the temperature of the K atoms to 9μK.Using this apparatus,both Rb and K are loaded into the optical tweezer.展开更多
BACKGROUND In December 2019,an ongoing outbreak of coronavirus disease 2019(COVID-19)was first identified in Wuhan,China.The characteristics of COVID-19 patients treated in local hospitals in Wuhan are not fully repre...BACKGROUND In December 2019,an ongoing outbreak of coronavirus disease 2019(COVID-19)was first identified in Wuhan,China.The characteristics of COVID-19 patients treated in local hospitals in Wuhan are not fully representative of patients outside Wuhan.Therefore,it is highly essential to analyze the epidemiological and clinical characteristics of COVID-19 in areas outside Wuhan or Hubei Province.To date,a limited number of studies have concentrated on the epidemiological and clinical characteristics of COVID-19 patients with different genders,clinical classification,and with or without basic diseases.AIM To study the epidemiological and clinical characteristics of COVID-19 patients in Hengyang(China)and provide a reliable reference for the prevention and control of COVID-19.METHODS From January 16 to March 2,2020,a total of 48 confirmed cases of COVID-19 were reported in Hengyang,and those cases were included in this study.The diagnostic criteria,clinical classification,and discharge standard related to COVID-19 were in line with the Diagnosis and Treatment Protocol for Novel Coronavirus Pneumonia(Trial Version 7)released by National Health Commission and National Administration of Traditional Chinese Medicine.The presence of SARS-CoV-2 in pharyngeal swab specimens was detected by quantitative reverse transcription polymerase chain reaction.All the data were imported into the excel worksheet and statistically analyzed by using SPSS 25.0 software.RESULTS A total of 48 cases of COVID-19 were collected,of which 1 was mild,38 were moderate,and 9 were severe.It was unveiled that there were 31(64.6%)male patients and 17(35.4%)female patients,with a female-to-male ratio of 1.82:1.The range of age of patients with COVID-19 was dominantly 30-49 years old[25(52.1%)of 48],followed by those aged over 60 years old[11(22.9%)].Besides,29.2%(14 of 48)of patients had basic diseases,and 57.2%(8 of 14)of patients with basic diseases were aged over 60 years old.The occupations of 48 COVID-19 patients were mainly farmers working in agricultural production[15(31.5%)of 48],rural migrant workers from Hengyang to Wuhan[15(31.5%)],and service workers operating in the service sector[8(16.7%)].The mean latent period was 6.86±3.57 d,and the median was 7[interquartile range(IQR):4-9]d.The mean time from onset of symptoms to the first physician visit was 3.38±2.98(95%CI:2.58-9.18)d,with a median of 2(IQR:1-5)d,and the mean time from hospital admission to confirmed diagnosis was 2.29±2.11(95%CI:1.18-6.42)d,with a median of 2(IQR:1-3)d.The main symptoms were fever[43(89.6%)of 48],cough and expectoration[41(85.4%)],fatigue[22(45.8%)],and chills[22(45.8%)].Other symptoms included poor appetite[13(27.1%)],sore throat[9(18.8%)],dyspnea[9(18.8%)],diarrhea[7(14.6%)],dizziness[5(10.4%)],headache[5(10.4%)],muscle pain[5(10.4%)],nausea and vomiting[4(8.3%)],hemoptysis[4(8.3%)],and runny nose[1(2.1%)].The numbers of peripheral blood leukocytes,lymphocytes,and eosinophils were significantly reduced in the majority of the patients.The levels of C-reactive protein,fibrinogen,blood glucose,lactate dehydrogenase,Ddimer,alanine aminotransferase(ALT),aspartate aminotransferase(AST),gamma-glutamyl transferase(γ-GT),myoglobin(MB),and creatine kinase(CK)were increased in 64.6%,44.7%,43.2%,37.0%,29.5%,22.9%,20.8%,21.6%,13.6%,and 12.8%of patients,respectively.The incidence of ALT elevation in male patients was remarkably higher than that in females(P<0.01),while the incidences of AST,CK,and blood glucose elevations in severe patients were remarkably higher than those in moderate patients(P<0.05,respectively).Except for the mild patients,chest computed tomography showed characteristic pulmonary lesions.All the patients received antiviral drugs,38(79.2%)accepted traditional Chinese medicine,and 2(4.2%)received treatment of human umbilical-cord mesenchymal stem cells.On March 2,2020,48 patients with COVID-19 were all cured and discharged.CONCLUSION Based on our results,patients with COVID-19 often have multiple organ dysfunction or damage.The incidences of ALT elevation in males,and AST,CK,and blood glucose elevations in severe patients are remarkably higher.展开更多
The Pinghu slope belt in the Xihu sag of the East China Sea Shelf Basin(ECSSB) is a crucial hydrocarbon production area in eastern China. However, due to the complex geological conditions, publications have lacked com...The Pinghu slope belt in the Xihu sag of the East China Sea Shelf Basin(ECSSB) is a crucial hydrocarbon production area in eastern China. However, due to the complex geological conditions, publications have lacked comprehensive research on the spatial-temporal coupling relationships of primary factors that impact hydrocarbon accumulation in the Pinghu slope belt. Furthermore, the hydrocarbon distribution patterns and the controlling factors across different study areas within the same slope belt are not yet fully understood. This study extensively utilized three-dimensional seismic data, well logging data,geochemical analysis, fluorescence analysis, and oil testing and production data to address these issues.Following a “stratification and differentiation” approach, the study identified seven distinct hydrocarbon migration and accumulation units(HMAU) in the Pinghu slope area based on the structural morphology characteristics, hydrocarbon source-reservoir-cap rock patterns, hydrocarbon migration pathways, and hydrocarbon supply range. Detailed analysis was conducted to examine the hydrocarbon distribution patterns and controlling factors within each migration and accumulation unit across different structural units, including high, medium, and low structural components. All data sources support a “southern-northern sub-area division, eastern-western sub-belt division, and variations in hydrocarbon accumulation” pattern in the Pinghu slope belt. The degree of hydrocarbon accumulation is controlled by the factors of structural morphology, hydrocarbon generation potential of source rocks, the spatial position of source slopes, fault sealing capacity, and sand body distribution. Furthermore, different coupling patterns of faults and sand bodies play a pivotal role in governing hydrocarbon enrichment systems across various migration and accumulation units. These observations indicate that three hydrocarbon accumulation patterns have been established within the slope belt, including near-source to far-source gentle slope with multiple hydrocarbon kitchens in the XP1-XP4 zones, near-source to middle-source gentle slope with dual-hydrocarbon kitchens in the XP5 zone, and near-source steep slope with a single hydrocarbon kitchen in the XP6-XP7 zones. These findings contribute to enhancing the theoretical system of hydrocarbon accumulation in the slope belt.展开更多
We investigate experimentally multi-orbital effects in high-order harmonic generation(HHG) from aligned CO2 and N2O molecules by intense femtosecond laser fields with linear and elliptical polarizations.For either of ...We investigate experimentally multi-orbital effects in high-order harmonic generation(HHG) from aligned CO2 and N2O molecules by intense femtosecond laser fields with linear and elliptical polarizations.For either of the aligned molecules, a minimum in the harmonic spectrum is observed, the position of which shifts to lower-order harmonics when decreasing the intensity or increasing the ellipticity of the driving laser.This indicates that the minimum originates from the dynamic interference of different channels, of which the tunneling ionization and recombination are contributed via different molecular orbitals.The results show that both the highest occupied molecular orbital(HOMO) and low-lying HOMO-2 in CO2(or HOMO-1 in N2O) contribute to the molecular HHG in both linearly and elliptically polarized strong laser fields.Our study would pave a way for understanding multi-electron dynamics from polyatomic molecules irradiated by strong laser fields.展开更多
n-Hexane is widely used in industrial production as an organic solvent. As an industrial exhaust gas, the contribution of n-hexane to air pollution and damage to human health are attracting increasing attention. In th...n-Hexane is widely used in industrial production as an organic solvent. As an industrial exhaust gas, the contribution of n-hexane to air pollution and damage to human health are attracting increasing attention. In the present study, aqueous solutions of two fluorocarbon surfactants（FSN100 and FSO100） were investigated for their properties of solubilization and dynamic absorption of n-hexane, as well as their capacity for regeneration and n-hexane recovery by thermal distillation. The results show that the two fluorocarbon surfactants enhance dissolution and absorption of n-hexane, and their effectiveness is closely related to their concentrations in solution. For low concentration solutions（0.01%–0.30%）, the partition coefficient decreases dramatically and the saturation capacity increases significantly with increasing concentration, but the changes for both are more modest when the concentration is over 0.30%. The FSO100 solution presents a smaller partition coefficient and a greater saturation capacity than the FSN100 solution at the same concentration,indicating a stronger solubilization for n-hexane. Thermal distillation is a feasible method to recover n-hexane from these absorption solutions, and to regenerate them. With 90 sec heating at 80–85°C, the recovery of n-hexane ranges between 81% and 85%, and the regenerated absorption solution maintains its original performance during reuse. This study provides basic information on two fluorocarbon surfactants for application in the treatment of industrial n-hexane waste gases.展开更多
Cerebral edema caused by blood-brain barrier injury after intracerebral hemorrhage is an important factor leading to poor prognosis.Human-induced pluripotent stem cell-derived neural stem cell exosomes(hiPSC-NSC-Exos)...Cerebral edema caused by blood-brain barrier injury after intracerebral hemorrhage is an important factor leading to poor prognosis.Human-induced pluripotent stem cell-derived neural stem cell exosomes(hiPSC-NSC-Exos)have shown potential for brain injury repair in central nervous system diseases.In this study,we explored the impact of hiPSC-NSC-Exos on blood-brain barrier preservation and the underlying mechanism.Our results indicated that intranasal delivery of hiPSC-NSC-Exos mitigated neurological deficits,enhanced blood-brain barrier integrity,and reduced leukocyte infiltration in a mouse model of intracerebral hemorrhage.Additionally,hiPSC-NSC-Exos decreased immune cell infiltration,activated astrocytes,and decreased the secretion of inflammatory cytokines like monocyte chemoattractant protein-1,macrophage inflammatory protein-1α,and tumor necrosis factor-αpost-intracerebral hemorrhage,thereby improving the inflammatory microenvironment.RNA sequencing indicated that hiPSC-NSC-Exo activated the PI3K/AKT signaling pathway in astrocytes and decreased monocyte chemoattractant protein-1 secretion,thereby improving blood-brain barrier integrity.Treatment with the PI3K/AKT inhibitor LY294002 or the monocyte chemoattractant protein-1 neutralizing agent C1142 abolished these effects.In summary,our findings suggest that hiPSC-NSC-Exos maintains blood-brain barrier integrity,in part by downregulating monocyte chemoattractant protein-1 secretion through activation of the PI3K/AKT signaling pathway in astrocytes.展开更多
Diamond coatings possess numerous excellent properties,making them desirable materials for high-performance surface applications.However,without a revolutionary surface modification method,the surface roughness and fr...Diamond coatings possess numerous excellent properties,making them desirable materials for high-performance surface applications.However,without a revolutionary surface modification method,the surface roughness and friction behavior of diamond coatings can impede their ability to meet the demanding requirements of advanced engineering surfaces.This study proposed the thermal stress control at coating interfaces and demonstrated a novel process of precise graphenization on conventional diamond coatings surface through laser induction and mechanical cleavage,without causing damage to the metal substrate.Through experiments and simulations,the influence mechanism of surface graphitization and interfacial thermal stress was elucidated,ultimately enabling rapid conversion of the diamond coating surface to graphene while controlling the coating’s thickness and roughness.Compared to the original diamond coatings,the obtained surfaces exhibited a 63%-72%reduction in friction coefficients,all of which were below 0.1,with a minimum of 0.06,and a 59%-67%decrease in specific wear rates.Moreover,adhesive wear in the friction counterpart was significantly inhibited,resulting in a reduction in wear by 49%-83%.This demonstrated a significant improvement in lubrication and inhibition of mechanochemical wear properties.This study provides an effective and cost-efficient avenue to overcome the application bottleneck of engineered diamond surfaces,with the potential to significantly enhance the performance and expand the application range of diamond-coated components.展开更多
Quantitative measurement of Soot Volume Fraction (SVF) is an essential prerequisite for controlling soot particle emissions from aero-engine combustors. As an in-situ and non-intrusive optical diagnostic technique, La...Quantitative measurement of Soot Volume Fraction (SVF) is an essential prerequisite for controlling soot particle emissions from aero-engine combustors. As an in-situ and non-intrusive optical diagnostic technique, Laser-Induced Incandescence (LII) has been increasingly applied for soot concentration quantification in various combustion environments such as laminar flame, vehicle exhaust, internal combustion chamber as well as aero-engine combustor. In this work, we experimentally measured the spatial and temporal distribution of SVF using two-color LII technique at the outlet of a single-sector dual-swirl aero-engine model combustor. The effect of inlet pressure and air preheat temperature on the SVF distribution was separately investigated within a pressure range of 241–425 kPa and a temperature range of 292–500 K. The results show that soot production increases with the inlet pressure but generally decreases with the air preheat temperature. Qualitative analysis was provided to explain the above results of parametric studies. The LII experiments were also conducted under 3 designed conditions to evaluate soot emission under practical operations. Particularly, weak soot emission was detected at the outlet under the idle condition. Our experimental results provide a valuable benchmark for evaluating soot emission in the exhaust plume of this aero-engine combustor during practical operations.展开更多
Precise and quantitative measurement of soot particle emission plays an essential role in accurately assessing the combustion performance of aero-engine combustors and infrared signature levels in aircraft exhausts.Am...Precise and quantitative measurement of soot particle emission plays an essential role in accurately assessing the combustion performance of aero-engine combustors and infrared signature levels in aircraft exhausts.Among various intrusive or non-intrusive approaches for soot diagnostics,Laser-Induced Incandescence(LⅡ)technique has been increasingly applied for soot concentration measurement in various combustion environments such as laminar flames and internal combustion engines due to its high spatial resolution and sensitivity.As for LⅡmeasurement in aero-engine combustors,however,it normally suffers from very limited optical accesses and often faces mandatory requirements of oblique imaging from a small backward angle.In this work,we demonstrate a Two-Color(2C)LⅡsystem that simultaneously captures LⅡsignal images at two distinct wavelengths using a Scheimpflug imaging configuration.A projective transformation algorithm and image overlapping procedures were employed to spatially correct the raw Scheimpflug LⅡimages.Performance validation of the developed 2C-Scheimpflug LⅡsystem was first conducted under specified conditions in a laminar C_(2)H_(4)/air McKenna flame.The obtained Soot Volume Fraction(SVF)level and its spatial distribution are in consistent with previous studies under identical flame conditions reported by other research groups.Finally,as a demonstration of engineering benchmark application,we applied the developed 2C-Scheimpflug LⅡsystem to measure SVF distribution in the cross-section plane perpendicular to the direction of flame propagation at the exhaust of a single-sector dual-swirl aero-engine model combustor.Transient soot production events were observed and characteristics of the SVF distribution were investigated.These experimental results suggest the feasibility of the 2C-Scheimpflug LⅡtechnique developed in this work for precise and quantitative measurements of soot concentration in practical environments.展开更多
Near-Earth Asteroids posed a threat to human civilization,making their monitoring crucial.As the demand for asteroid detection technology increased,precise detection of these celestial bodies became an urgent task to ...Near-Earth Asteroids posed a threat to human civilization,making their monitoring crucial.As the demand for asteroid detection technology increased,precise detection of these celestial bodies became an urgent task to understand their characteristics and assess potential impact risks.To improve asteroid detection accuracy and efficiency,we proposed an advanced image processing method and a deep learning network for automatic asteroid detection.Specifically,we aligned star clusters and overlaid images to exploit asteroid motion rates,transforming them into object-like trajectories and improving the signal-to-noise ratio.This approach created the Asteroid Trajectory Image Data set under various conditions.We modified CenterNet2 network to develop AstroCenterNet by integrating Multi-channel Histogram Truncation for feature enhancement,using the SimAM attention mechanism to expand contextual information and suppress noise,and refining Feature Pyramid Network to improve low-level feature detection.Our results demonstrated a detection accuracy of 98.4%,a recall of 97.6%,a mean Average Precision of 94.01%,a false alarm rate of 1.6%,and a processing speed of approximately 17.86 frames per second,indicating that our method achieves high precision and efficiency.展开更多
Harnessing solar energy to enhance the rechargeable zinc-air batteries(RZABs)performance is a promising avenue toward sustainable energy storage and conversion.Simultaneously enhancing light-absorption capacity and ca...Harnessing solar energy to enhance the rechargeable zinc-air batteries(RZABs)performance is a promising avenue toward sustainable energy storage and conversion.Simultaneously enhancing light-absorption capacity and carrier separation efficiency in nanomaterials,as well as improving electrical conductivity and configuration for electrocatalysis,presents a formidable challenge due to inherent trade-offs and interdependencies.Here,we have developed a Janus dual-atom catalyst(JDAC)with bifunctional centers for efficient charge separation and electrocatalytic performance through a bipolar doping strategy.The in situ X-ray absorption near-edge structure and Raman spectroscopy analyses demonstrated that the Ni and Fe centers in JDAC not only function as effective sites for oxygen evolution reaction and oxygen reduction reaction,respectively,but also serve as efficient hole and electron enrichment sites,effectively suppressing photoelectron recombination while enhancing photocurrent generation.As a result,the assembled JDAC-based lightassisted RZABs exhibited extraordinary stability at large current densities.This work delivers pivotal insight to design Janus dual-atom catalysts that efficiently convert solar energy into electric and chemical energy.展开更多
Tracking control of tendon-driven manipulators has become a prevalent research area.However,the existence of flexible elastic tendons generates substantial residual vibrations,resulting in difficulties for trajectory ...Tracking control of tendon-driven manipulators has become a prevalent research area.However,the existence of flexible elastic tendons generates substantial residual vibrations,resulting in difficulties for trajectory tracking control of the manipulator.This paper proposes the radial basis function neural network adaptive hierarchical sliding mode control(RBFNNA-HSMC)method,which combines the dynamic model of the elastic tendon-driven manipulator(ETDM)with radial basis neural network adaptive control and hierarchical sliding mode control technology.The aim is to achieve trajectory tracking control of ETDM even under conditions of model inaccuracy and disturbance.The Lyapunov stability theory demonstrates the stability of the proposed RBFNNA-HSM controller.In order to assess the effectiveness and adaptability of the proposed control method,simulations and experiments were performed on a two-DOF ETDM.The RBFNNA-HSM method shows superior tracking accuracy compared to traditional modelbased HSM control.The experiment shows that the maximum tracking error for ETDM double-joint trajectory tracking is below 2.593×10-3rad and 1.624×10-3rad,respectively.展开更多
基金supported by the National Key R&D Program of China(2022YFB3807700)the National Natural Science Foundation of China(52072217,22179071,51772169,and 52104313)+3 种基金the Hubei Provincial Natural Science Foundation of China(2023AFB618 and 2024AFB993)the Hubei Natural Science Foundation Innovation Group Project(2022CFA020)the Joint Funds of the Hubei Natural Science Foundation Innovation and Development(2022CFD034)the Major Technological Innovation Project of Hubei Science and Technology Department(2019AAA164)。
文摘Black phosphorus(BP)is recognized as a promising anode for sodium-ion batteries(SIBs)due to its high safety and theoretical capacity.However,traditional ball milling methodologies for fabricating BP composite anodes have not satisfactorily addressed the challenges of poor rate performance and short cycle life.To fill this scientific gap,we herein pioneer incorporating the sodium fast ionic conductorβ"-Al_(2)O_(3)into ball-milled BP with carbon,which facilitates the formation of three-dimensional mass transfer channels in the resulting composite.To stabilize these channels,we develop a novel and environmentally friendly functional binder that outperforms traditional binders in thermal stability,wettability,and mechanical properties.The newly established binder is capable of remarkably mitigating volume expansion and interfacial side reactions in the BP/β"-Al_(2)O_(3)/C composite anode.Additionally,we identify synergistic effects of the binder interacting with the BP/β"-Al_(2)O_(3)/C composite during cycling,characterized by the in-situ formation of P-O-C bonds,which is the first instance of a strong,durable chemical bond between the binder and the active material to the best of our knowledge.These advancements allow the composite electrode to exhibit exceptional sodium storage,including high initial Coulombic efficiency and long-term cycling stability,which surpasses most previous phosphorus-based anodes fabricated via traditional approaches.Notably,when paired with a Na_(4)Fe_(3)(PO_(4))_(2)P_(2)O_7(NFPP)cathode,the full cell exhibits unexpectedly high energy and power densities,highlighting the BP potential in SIBs.The findings presented in the present work contribute to the promotion of economical and efficient applications of phosphorus-based anode materials.
基金supported by the Science and Technology Major Project of the Sichuan Institute of Geological Survey(SCIGS-CZDXM-2023003)the National Natural Science Foundation of China(41603034).
文摘1.Objective The Songpan-Ganze terrane is a key region for understanding the tectonic evolution of the Tibetan Plateau and the Yangtze Craton.The Songpan-Ganzi complex comprises a thick succession of deformed Ladinian-Norian turbidites(ca.230-203 Ma),covering about 200000 km^(2)of the eastern Tibet Plateau with a volume of approximately 2.0×10^(6)km^(3)(Fig.1a).Furthermore,this complex has over 100 Permian-Cenozoic felsic plutons.
基金supported by Guangdong Basic and Applied Basic Research Foundation(Nos.2021B1515120055 and 2022A1515010499).
文摘Urban rainwater runoff is an important source of nonpoint source pollution due to its transport of diverse contaminants,including polycyclic aromatic hydrocarbons(PAHs)and chlorinated derivatives.Importantly,these chlorinated polycyclic aromatic hydrocarbons(Cl-PAHs)exhibit elevated toxicological potential compared to their non-halogenated parent compounds.In this study,we proposed an approach that combined multivariate receptor model with integration of SHapley Additive exPlanations and Random Forest model.This method identifies the possible sources and reveals the impact of source apportionment results and environmental driving factors(such as geographical and meteorological data)on pollutant concentrations.Sixteen PAHs and nine ClPAHs were detected in 79 runoff samples from all three sites.TheΣ_(16)PAHs average concentration(2923.93 to 6071.83 ng/L)was significantly higher than theΣ_(9)Cl-PAHs(384.34 to 1314.73 ng/L).The source apportionment was conducted by positive matrix factorization(PMF),and six potential pollution sources for PAHs and three for Cl-PAHs were quantified.PAHs primarily originate from the combustion of fossil fuels such as traffic,industrial emissions and coal tar,while Cl-PAHs are mainly derived from atmospheric deposition and industrial emissions.Meanwhile,the self‑organizing map classified PAHs and Cl-PAHs into 2 and 3 groups,respectively.The k-means algorithm yielded 4 clusters for runoff samples.Among machine learning models,Random Forest(RF)demonstrated optimal predictive performance and integrated with SHapley Additive exPlanations(RF-SHAP)revealed the effects of driving factors on the predicted concentration of PAHs and Cl-PAHs in urban runoff samples.
基金supported by the National Natural Science Foundation of China(82271401,82071394)the Tianjin Health Research Project(TJWJ2024RC002)。
文摘Background:Repetitive mild traumatic brain injury(rmTBI)is a significant risk factor for neurodegeneration,characterized by pathological protein deposition and persistent neuroinflammation.Research has observed increased interleukin-33(IL-33)levels in the peripheral blood of patients with rmTBI,suggesting IL-33 may participate in regulating the pathological development of rmTBI.The study aims to elucidate the impact and mechanism of IL-33 in the progression of neuropathology following rmTBI,and to explore its potential as a therapeutic target to improve the neurological outcome.Methods:The study employed an rmTBI mouse model using the wild-type(WT)and IL-33 knockout mice.Cognitive function was assessed via the Y-maze and Barnes tests.The main cell type expressing IL-33 and its receptor,suppression of tumorigenicity 2(ST2),was then investigated in the mouse brain through immunofluorescence colocalization.As the primary neural cell responsible for ST2 expression,microglia were studied in vitro using the BV2 cell line.The effects of lipid droplets(LDs)accumulation and amyloid-beta(Aβ)phagocytosis were measured to elucidate the impact of IL-33 on BV2 cells'phagocytosis.Additionally,HT22 neuronal apoptosis was assessed by flow cytometry.Finally,the cognitive effects of intranasal administration of IL-33 were evaluated in mice.Results:IL-33 KO mice exhibited pronounced cognitive impairment after rmTBI.In the mouse brain,astrocytes were identified as the primary source of IL-33 secretion,while microglia predominantly expressed ST2.Transcriptome sequencing revealed that IL-33 significantly influenced phagocytosis function.IL-33 mitigated LDs accumulation in BV2 cells and enhanced Aβphagocytosis in vitro.In addition,the culture medium of BV2 cells with activated IL-33/ST2 signaling reduced HT22 neuronal apoptosis and axonal damage.Furthermore,intranasal administration of IL-33 was observed to be effective in alleviating neurodegeneration and cognitive outcome of rmTBI mice.Conclusions:Dysfunction of the IL-33/ST2 axis following rmTBI leads to cognitive dysfunction via impairing microglial phagocytosis capacity and promoting neuronal damage.IL-33 would be a promising therapeutic target for alleviating neurodegeneration following rmTBI.
基金Project supported by the National Key Research and Development Program of China(Grant Nos.2023YFA1406703 and 2022YFA1404203)the National Natural Science Foundation of China(Grant Nos.12425408,U21A20437 and 12074337)+1 种基金the Natural Science Foundation of Zhejiang Province,China(Grant No.LR21A040002)the Fundamental Research Funds for the Central Universities(Grant No.226-2023-00131)。
文摘The optical tweezer experiment with neutral atoms is widely used for quantum information research.Here,we present a compact dual magneto-optical trap(MOT)setup for a two-species optical tweezer.Rubidium(Rb)atoms are directly captured using a vapor MOT,while potassium(K)atoms are collected via a 2-stage MOT.Both the quadratic and gradient magnetic fields required for the MOT and Zeeman slower are created by permanent magnets.With the help of the Zeeman slower,the K MOT loading efficiency is enhanced by a factor of three.After the MOT stage,we apply D_(1) gray molasses to reduce the temperature of the K atoms to 9μK.Using this apparatus,both Rb and K are loaded into the optical tweezer.
基金Supported by the Novel Coronavirus Pneumonia Emergency Project of University of South China,No.2020-15 and No.2020-25the Hengyang Science and Technology Plan Project-Basic Research Project of Prevention and Treatment of the Novel Coronavirus Pneumonia,No.202010031577+2 种基金the Scientific Research Project of Hunan Provincial Health and Family Planning Commission,No.A2017015the Natural Science Foundation of Hunan Province,China,No.2016JJ5010the National Natural Science Foundation of China,No.81373465.
文摘BACKGROUND In December 2019,an ongoing outbreak of coronavirus disease 2019(COVID-19)was first identified in Wuhan,China.The characteristics of COVID-19 patients treated in local hospitals in Wuhan are not fully representative of patients outside Wuhan.Therefore,it is highly essential to analyze the epidemiological and clinical characteristics of COVID-19 in areas outside Wuhan or Hubei Province.To date,a limited number of studies have concentrated on the epidemiological and clinical characteristics of COVID-19 patients with different genders,clinical classification,and with or without basic diseases.AIM To study the epidemiological and clinical characteristics of COVID-19 patients in Hengyang(China)and provide a reliable reference for the prevention and control of COVID-19.METHODS From January 16 to March 2,2020,a total of 48 confirmed cases of COVID-19 were reported in Hengyang,and those cases were included in this study.The diagnostic criteria,clinical classification,and discharge standard related to COVID-19 were in line with the Diagnosis and Treatment Protocol for Novel Coronavirus Pneumonia(Trial Version 7)released by National Health Commission and National Administration of Traditional Chinese Medicine.The presence of SARS-CoV-2 in pharyngeal swab specimens was detected by quantitative reverse transcription polymerase chain reaction.All the data were imported into the excel worksheet and statistically analyzed by using SPSS 25.0 software.RESULTS A total of 48 cases of COVID-19 were collected,of which 1 was mild,38 were moderate,and 9 were severe.It was unveiled that there were 31(64.6%)male patients and 17(35.4%)female patients,with a female-to-male ratio of 1.82:1.The range of age of patients with COVID-19 was dominantly 30-49 years old[25(52.1%)of 48],followed by those aged over 60 years old[11(22.9%)].Besides,29.2%(14 of 48)of patients had basic diseases,and 57.2%(8 of 14)of patients with basic diseases were aged over 60 years old.The occupations of 48 COVID-19 patients were mainly farmers working in agricultural production[15(31.5%)of 48],rural migrant workers from Hengyang to Wuhan[15(31.5%)],and service workers operating in the service sector[8(16.7%)].The mean latent period was 6.86±3.57 d,and the median was 7[interquartile range(IQR):4-9]d.The mean time from onset of symptoms to the first physician visit was 3.38±2.98(95%CI:2.58-9.18)d,with a median of 2(IQR:1-5)d,and the mean time from hospital admission to confirmed diagnosis was 2.29±2.11(95%CI:1.18-6.42)d,with a median of 2(IQR:1-3)d.The main symptoms were fever[43(89.6%)of 48],cough and expectoration[41(85.4%)],fatigue[22(45.8%)],and chills[22(45.8%)].Other symptoms included poor appetite[13(27.1%)],sore throat[9(18.8%)],dyspnea[9(18.8%)],diarrhea[7(14.6%)],dizziness[5(10.4%)],headache[5(10.4%)],muscle pain[5(10.4%)],nausea and vomiting[4(8.3%)],hemoptysis[4(8.3%)],and runny nose[1(2.1%)].The numbers of peripheral blood leukocytes,lymphocytes,and eosinophils were significantly reduced in the majority of the patients.The levels of C-reactive protein,fibrinogen,blood glucose,lactate dehydrogenase,Ddimer,alanine aminotransferase(ALT),aspartate aminotransferase(AST),gamma-glutamyl transferase(γ-GT),myoglobin(MB),and creatine kinase(CK)were increased in 64.6%,44.7%,43.2%,37.0%,29.5%,22.9%,20.8%,21.6%,13.6%,and 12.8%of patients,respectively.The incidence of ALT elevation in male patients was remarkably higher than that in females(P<0.01),while the incidences of AST,CK,and blood glucose elevations in severe patients were remarkably higher than those in moderate patients(P<0.05,respectively).Except for the mild patients,chest computed tomography showed characteristic pulmonary lesions.All the patients received antiviral drugs,38(79.2%)accepted traditional Chinese medicine,and 2(4.2%)received treatment of human umbilical-cord mesenchymal stem cells.On March 2,2020,48 patients with COVID-19 were all cured and discharged.CONCLUSION Based on our results,patients with COVID-19 often have multiple organ dysfunction or damage.The incidences of ALT elevation in males,and AST,CK,and blood glucose elevations in severe patients are remarkably higher.
基金funded by the Natural Science Foundation of Heilongjiang Province (LH 2022D013)supported by the Central Support Program for Young Talents in Local Universities in Heilongjiang Province (14011202101)Key Research and Development Plan Project of Heilongjiang Province (JD22A022)。
文摘The Pinghu slope belt in the Xihu sag of the East China Sea Shelf Basin(ECSSB) is a crucial hydrocarbon production area in eastern China. However, due to the complex geological conditions, publications have lacked comprehensive research on the spatial-temporal coupling relationships of primary factors that impact hydrocarbon accumulation in the Pinghu slope belt. Furthermore, the hydrocarbon distribution patterns and the controlling factors across different study areas within the same slope belt are not yet fully understood. This study extensively utilized three-dimensional seismic data, well logging data,geochemical analysis, fluorescence analysis, and oil testing and production data to address these issues.Following a “stratification and differentiation” approach, the study identified seven distinct hydrocarbon migration and accumulation units(HMAU) in the Pinghu slope area based on the structural morphology characteristics, hydrocarbon source-reservoir-cap rock patterns, hydrocarbon migration pathways, and hydrocarbon supply range. Detailed analysis was conducted to examine the hydrocarbon distribution patterns and controlling factors within each migration and accumulation unit across different structural units, including high, medium, and low structural components. All data sources support a “southern-northern sub-area division, eastern-western sub-belt division, and variations in hydrocarbon accumulation” pattern in the Pinghu slope belt. The degree of hydrocarbon accumulation is controlled by the factors of structural morphology, hydrocarbon generation potential of source rocks, the spatial position of source slopes, fault sealing capacity, and sand body distribution. Furthermore, different coupling patterns of faults and sand bodies play a pivotal role in governing hydrocarbon enrichment systems across various migration and accumulation units. These observations indicate that three hydrocarbon accumulation patterns have been established within the slope belt, including near-source to far-source gentle slope with multiple hydrocarbon kitchens in the XP1-XP4 zones, near-source to middle-source gentle slope with dual-hydrocarbon kitchens in the XP5 zone, and near-source steep slope with a single hydrocarbon kitchen in the XP6-XP7 zones. These findings contribute to enhancing the theoretical system of hydrocarbon accumulation in the slope belt.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.91750104,11534004,11874179,11127403,11474130)the Natural Science Foundation of Jilin Province,China(Grant No.20180101289JC)
文摘We investigate experimentally multi-orbital effects in high-order harmonic generation(HHG) from aligned CO2 and N2O molecules by intense femtosecond laser fields with linear and elliptical polarizations.For either of the aligned molecules, a minimum in the harmonic spectrum is observed, the position of which shifts to lower-order harmonics when decreasing the intensity or increasing the ellipticity of the driving laser.This indicates that the minimum originates from the dynamic interference of different channels, of which the tunneling ionization and recombination are contributed via different molecular orbitals.The results show that both the highest occupied molecular orbital(HOMO) and low-lying HOMO-2 in CO2(or HOMO-1 in N2O) contribute to the molecular HHG in both linearly and elliptically polarized strong laser fields.Our study would pave a way for understanding multi-electron dynamics from polyatomic molecules irradiated by strong laser fields.
基金supported by Guangdong Natural Science Funds for Distinguished Young Scholar (No. S2013050014122)Guangzhou Institute of Geochemistry, Chinese Academy of Sciences (No. 2012-03) (135 project)No. IS-2062 from GIGGAS
文摘n-Hexane is widely used in industrial production as an organic solvent. As an industrial exhaust gas, the contribution of n-hexane to air pollution and damage to human health are attracting increasing attention. In the present study, aqueous solutions of two fluorocarbon surfactants（FSN100 and FSO100） were investigated for their properties of solubilization and dynamic absorption of n-hexane, as well as their capacity for regeneration and n-hexane recovery by thermal distillation. The results show that the two fluorocarbon surfactants enhance dissolution and absorption of n-hexane, and their effectiveness is closely related to their concentrations in solution. For low concentration solutions（0.01%–0.30%）, the partition coefficient decreases dramatically and the saturation capacity increases significantly with increasing concentration, but the changes for both are more modest when the concentration is over 0.30%. The FSO100 solution presents a smaller partition coefficient and a greater saturation capacity than the FSN100 solution at the same concentration,indicating a stronger solubilization for n-hexane. Thermal distillation is a feasible method to recover n-hexane from these absorption solutions, and to regenerate them. With 90 sec heating at 80–85°C, the recovery of n-hexane ranges between 81% and 85%, and the regenerated absorption solution maintains its original performance during reuse. This study provides basic information on two fluorocarbon surfactants for application in the treatment of industrial n-hexane waste gases.
基金supported by the National Natural Science Foundation of China,No.8227050826(to PL)Tianjin Science and Technology Bureau Foundation,No.20201194(to PL)Tianjin Graduate Research and Innovation Project,No.2022BKY174(to CW).
文摘Cerebral edema caused by blood-brain barrier injury after intracerebral hemorrhage is an important factor leading to poor prognosis.Human-induced pluripotent stem cell-derived neural stem cell exosomes(hiPSC-NSC-Exos)have shown potential for brain injury repair in central nervous system diseases.In this study,we explored the impact of hiPSC-NSC-Exos on blood-brain barrier preservation and the underlying mechanism.Our results indicated that intranasal delivery of hiPSC-NSC-Exos mitigated neurological deficits,enhanced blood-brain barrier integrity,and reduced leukocyte infiltration in a mouse model of intracerebral hemorrhage.Additionally,hiPSC-NSC-Exos decreased immune cell infiltration,activated astrocytes,and decreased the secretion of inflammatory cytokines like monocyte chemoattractant protein-1,macrophage inflammatory protein-1α,and tumor necrosis factor-αpost-intracerebral hemorrhage,thereby improving the inflammatory microenvironment.RNA sequencing indicated that hiPSC-NSC-Exo activated the PI3K/AKT signaling pathway in astrocytes and decreased monocyte chemoattractant protein-1 secretion,thereby improving blood-brain barrier integrity.Treatment with the PI3K/AKT inhibitor LY294002 or the monocyte chemoattractant protein-1 neutralizing agent C1142 abolished these effects.In summary,our findings suggest that hiPSC-NSC-Exos maintains blood-brain barrier integrity,in part by downregulating monocyte chemoattractant protein-1 secretion through activation of the PI3K/AKT signaling pathway in astrocytes.
基金support from the National Natural Science Foundation of China(NSFC)[No.52475464,52475463]National Natural Science Foundation of Jiangsu Province(No.BK20231442)+4 种基金the Fundamental Research Funds for the Central Universities(No.NS2024032)the International Joint Laboratory of Sustainable Manufacturing,Ministry of Education and the Fundamental Research Funds for the Central Universities(No.NG2024007)China Scholarship Council(No.202206830048)the Foundation of the Graduate Innovation Center,Nanjing University of Aeronautics and Astronautics(No.kfjj20200510)Funding for Outstanding Doctoral Dissertation in NUAA(No.BCXJ23-09)。
文摘Diamond coatings possess numerous excellent properties,making them desirable materials for high-performance surface applications.However,without a revolutionary surface modification method,the surface roughness and friction behavior of diamond coatings can impede their ability to meet the demanding requirements of advanced engineering surfaces.This study proposed the thermal stress control at coating interfaces and demonstrated a novel process of precise graphenization on conventional diamond coatings surface through laser induction and mechanical cleavage,without causing damage to the metal substrate.Through experiments and simulations,the influence mechanism of surface graphitization and interfacial thermal stress was elucidated,ultimately enabling rapid conversion of the diamond coating surface to graphene while controlling the coating’s thickness and roughness.Compared to the original diamond coatings,the obtained surfaces exhibited a 63%-72%reduction in friction coefficients,all of which were below 0.1,with a minimum of 0.06,and a 59%-67%decrease in specific wear rates.Moreover,adhesive wear in the friction counterpart was significantly inhibited,resulting in a reduction in wear by 49%-83%.This demonstrated a significant improvement in lubrication and inhibition of mechanochemical wear properties.This study provides an effective and cost-efficient avenue to overcome the application bottleneck of engineered diamond surfaces,with the potential to significantly enhance the performance and expand the application range of diamond-coated components.
基金supported by the National Key Research and Development Program of China(No.2020YFA0405700).
文摘Quantitative measurement of Soot Volume Fraction (SVF) is an essential prerequisite for controlling soot particle emissions from aero-engine combustors. As an in-situ and non-intrusive optical diagnostic technique, Laser-Induced Incandescence (LII) has been increasingly applied for soot concentration quantification in various combustion environments such as laminar flame, vehicle exhaust, internal combustion chamber as well as aero-engine combustor. In this work, we experimentally measured the spatial and temporal distribution of SVF using two-color LII technique at the outlet of a single-sector dual-swirl aero-engine model combustor. The effect of inlet pressure and air preheat temperature on the SVF distribution was separately investigated within a pressure range of 241–425 kPa and a temperature range of 292–500 K. The results show that soot production increases with the inlet pressure but generally decreases with the air preheat temperature. Qualitative analysis was provided to explain the above results of parametric studies. The LII experiments were also conducted under 3 designed conditions to evaluate soot emission under practical operations. Particularly, weak soot emission was detected at the outlet under the idle condition. Our experimental results provide a valuable benchmark for evaluating soot emission in the exhaust plume of this aero-engine combustor during practical operations.
基金supported by the Equipment Test and Evaluation Technology Research Project,China(No.2100070017)the Natural Science Foundation of Gansu Province,China(No.24JRRA415)。
文摘Precise and quantitative measurement of soot particle emission plays an essential role in accurately assessing the combustion performance of aero-engine combustors and infrared signature levels in aircraft exhausts.Among various intrusive or non-intrusive approaches for soot diagnostics,Laser-Induced Incandescence(LⅡ)technique has been increasingly applied for soot concentration measurement in various combustion environments such as laminar flames and internal combustion engines due to its high spatial resolution and sensitivity.As for LⅡmeasurement in aero-engine combustors,however,it normally suffers from very limited optical accesses and often faces mandatory requirements of oblique imaging from a small backward angle.In this work,we demonstrate a Two-Color(2C)LⅡsystem that simultaneously captures LⅡsignal images at two distinct wavelengths using a Scheimpflug imaging configuration.A projective transformation algorithm and image overlapping procedures were employed to spatially correct the raw Scheimpflug LⅡimages.Performance validation of the developed 2C-Scheimpflug LⅡsystem was first conducted under specified conditions in a laminar C_(2)H_(4)/air McKenna flame.The obtained Soot Volume Fraction(SVF)level and its spatial distribution are in consistent with previous studies under identical flame conditions reported by other research groups.Finally,as a demonstration of engineering benchmark application,we applied the developed 2C-Scheimpflug LⅡsystem to measure SVF distribution in the cross-section plane perpendicular to the direction of flame propagation at the exhaust of a single-sector dual-swirl aero-engine model combustor.Transient soot production events were observed and characteristics of the SVF distribution were investigated.These experimental results suggest the feasibility of the 2C-Scheimpflug LⅡtechnique developed in this work for precise and quantitative measurements of soot concentration in practical environments.
基金funded by the National Science and Technology Major Project(2022ZD0117401)the National Defense Science and Technology Innovation Special Zone Project Foundation of China(grant No.19-163-21-TS-001-067-01)support was provided by the Chinese Academy of Sciences(CAS)“Light of West China”Program(No.2020-XBQNXZ-016 and No.2022-XBQNXZ-016).
文摘Near-Earth Asteroids posed a threat to human civilization,making their monitoring crucial.As the demand for asteroid detection technology increased,precise detection of these celestial bodies became an urgent task to understand their characteristics and assess potential impact risks.To improve asteroid detection accuracy and efficiency,we proposed an advanced image processing method and a deep learning network for automatic asteroid detection.Specifically,we aligned star clusters and overlaid images to exploit asteroid motion rates,transforming them into object-like trajectories and improving the signal-to-noise ratio.This approach created the Asteroid Trajectory Image Data set under various conditions.We modified CenterNet2 network to develop AstroCenterNet by integrating Multi-channel Histogram Truncation for feature enhancement,using the SimAM attention mechanism to expand contextual information and suppress noise,and refining Feature Pyramid Network to improve low-level feature detection.Our results demonstrated a detection accuracy of 98.4%,a recall of 97.6%,a mean Average Precision of 94.01%,a false alarm rate of 1.6%,and a processing speed of approximately 17.86 frames per second,indicating that our method achieves high precision and efficiency.
基金supported by the National Key R&D Program of China(2024YFB4607600)National Natural Science Foundation of China(NSFC,Grant No.52303359)+1 种基金Basic and Applied Basic Research Foundation of Guangdong Province(2023A1515011511,2022A1515110848,2023B1515040027,Young Top Talents Program 2021QN02C174)Open program of State Key Laboratory of Optoelectronic Materials and Technologies(OEMT-2024-KF-06).
文摘Harnessing solar energy to enhance the rechargeable zinc-air batteries(RZABs)performance is a promising avenue toward sustainable energy storage and conversion.Simultaneously enhancing light-absorption capacity and carrier separation efficiency in nanomaterials,as well as improving electrical conductivity and configuration for electrocatalysis,presents a formidable challenge due to inherent trade-offs and interdependencies.Here,we have developed a Janus dual-atom catalyst(JDAC)with bifunctional centers for efficient charge separation and electrocatalytic performance through a bipolar doping strategy.The in situ X-ray absorption near-edge structure and Raman spectroscopy analyses demonstrated that the Ni and Fe centers in JDAC not only function as effective sites for oxygen evolution reaction and oxygen reduction reaction,respectively,but also serve as efficient hole and electron enrichment sites,effectively suppressing photoelectron recombination while enhancing photocurrent generation.As a result,the assembled JDAC-based lightassisted RZABs exhibited extraordinary stability at large current densities.This work delivers pivotal insight to design Janus dual-atom catalysts that efficiently convert solar energy into electric and chemical energy.
基金Supported by Key R&D Project of Zhejiang(Grant No.2022C02052)。
文摘Tracking control of tendon-driven manipulators has become a prevalent research area.However,the existence of flexible elastic tendons generates substantial residual vibrations,resulting in difficulties for trajectory tracking control of the manipulator.This paper proposes the radial basis function neural network adaptive hierarchical sliding mode control(RBFNNA-HSMC)method,which combines the dynamic model of the elastic tendon-driven manipulator(ETDM)with radial basis neural network adaptive control and hierarchical sliding mode control technology.The aim is to achieve trajectory tracking control of ETDM even under conditions of model inaccuracy and disturbance.The Lyapunov stability theory demonstrates the stability of the proposed RBFNNA-HSM controller.In order to assess the effectiveness and adaptability of the proposed control method,simulations and experiments were performed on a two-DOF ETDM.The RBFNNA-HSM method shows superior tracking accuracy compared to traditional modelbased HSM control.The experiment shows that the maximum tracking error for ETDM double-joint trajectory tracking is below 2.593×10-3rad and 1.624×10-3rad,respectively.
