The new energy power generation is becoming increasingly important in the power system.Such as photovoltaic power generation has become a research hotspot,however,due to the characteristics of light radiation changes,...The new energy power generation is becoming increasingly important in the power system.Such as photovoltaic power generation has become a research hotspot,however,due to the characteristics of light radiation changes,photovoltaic power generation is unstable and random,resulting in a low utilization rate and directly affecting the stability of the power grid.To solve this problem,this paper proposes a coordinated control strategy for a newenergy power generation system with a hybrid energy storage unit based on the lithium iron phosphate-supercapacitor hybrid energy storage unit.Firstly,the variational mode decomposition algorithm is used to separate the high and low frequencies of the power signal,which is conducive to the rapid and accurate suppression of the power fluctuation of the energy storage system.Secondly,the fuzzy control algorithm is introduced to balance the power between energy storage.In this paper,the actual data is used for simulation,and the simulation results show that the strategy realizes the effective suppression of the bus voltage fluctuation and the accurate control of the internal state of the energy storage unit,effectively avoiding problems such as overshoot and over-discharge,and can significantly improve the stability of the photovoltaic power generation systemand the stability of the Direct Current bus.It is of great significance to promote the development of collaborative control technology for photovoltaic hybrid energy storage units.展开更多
In this work,the combined addition of strontium/indium(Sr/In)to the magnesium anode for Mg-Air Cells is investigated to improve discharge performance by modifying the anode/electrolyte interface.Indium exists as solid...In this work,the combined addition of strontium/indium(Sr/In)to the magnesium anode for Mg-Air Cells is investigated to improve discharge performance by modifying the anode/electrolyte interface.Indium exists as solid solution atoms in theα-Mg matrix without its second-phase generation,and at the same time facilitates grain refinement,dendritic segregation and Mg17Sr2-phases precipitation.During discharge operation,Sr modifies the film composition via its compounds and promoted the redeposition of In at the substrate/film interface;their co-deposition behavior on the anodic reaction surface enhances anode reaction kinetics,suppresses the negative difference effect(NDE)and mitigates the“chunk effect”(CE),which is contributed to uniform dissolution and low self-corrosion hydrogen evolution rate(HER).Therefore,Mg-Sr-xIn alloy anodes show excellent discharge performance,e.g.,0.5Sr-1.0In shows an average discharge voltage of 1.4234 V and a specific energy density of 1990.71 Wh kg^(-1)at 10 mA cm^(-2).Furthermore,the decisive factor(CE and self-discharge HE)for anodic efficiency are quantitively analyzed,the self-discharge is the main factor of cell efficiency loss.Surprisingly,all Mg-Sr-xIn anodes show anodic efficiency greater than 60%at high current density(≥10 mA cm^(-2)),making them excellent candidate anodes for Mg-Air cells at high-power output.展开更多
The reaction rate constant is a crucial kinetic parameter that governs the charge and discharge performance of batteries,particularly in high-rate and thick-electrode applications.However,conventional estimation or fi...The reaction rate constant is a crucial kinetic parameter that governs the charge and discharge performance of batteries,particularly in high-rate and thick-electrode applications.However,conventional estimation or fitting methods often overestimate the charge transfer overpotential,leading to substantial errors in reaction rate constant measurements.These inaccuracies hinder the accurate prediction of voltage profiles and overall cell performance.In this study,we propose the characteristic time-decomposed overpotential(CTDO)method,which employs a single-layer particle electrode(SLPE)structure to eliminate interference overpotentials.By leveraging the distribution of relaxation times(DRT),our method effectively isolates the characteristic time of the charge transfer process,enabling a more precise determination of the reaction rate constant.Simulation results indicate that our approach reduces measurement errors to below 2%,closely aligning with theoretical values.Furthermore,experimental validation demonstrates an 80% reduction in error compared to the conventional galvanostatic intermittent titration technique(GITT)method.Overall,this study provides a novel voltage-based approach for determining the reaction rate constant,enhancing the applicability of theoretical analysis in electrode structural design and facilitating rapid battery optimization.展开更多
Constructing silicon(Si)-based composite electrodes that possess high energy density,long cycle life,and fast charging capability simultaneously is critical for the development of high performance lithium-ion batterie...Constructing silicon(Si)-based composite electrodes that possess high energy density,long cycle life,and fast charging capability simultaneously is critical for the development of high performance lithium-ion batteries for mitigating range anxiety and slow charging issues in new energy vehicles.Herein,a thick silicon/carbon composite electrode with vertically aligned channels in the thickness direction(VC-SC)is constructed by employing a bubble formation method.Both experimental characterizations and theoretical simulations confirm that the obtained vertical channel structure can effectively address the problem of sluggish ion transport caused by high tortuosity in conventional thick electrodes,conspicuously enhance reaction kinetics,reduce polarization and side reactions,mitigate stress,increase the utilization of active materials,and promote cycling stability of the thick electrode.Consequently,when paired with LiNi_(0.6)Co_(0.2)Mn_(0.2)O_(2)(NCM622),the VC-SC||NCM622 pouch type full cell(~6.0 mAh cm^(-2))exhibits significantly improved rate performance and capacity retention compared with the SC||NCM622 full cell with the conventional silicon/carbon composite electrode without channels(SC)as the anode.The assembled VC-SC||NCM622 pouch full cell with a high energy density of 490.3 Wh kg^(-1)also reveals a remarkable fast charging capability at a high current density of 2.0 mA cm^(-2),with a capacity retention of 72.0%after 500 cycles.展开更多
This study analyzes the potential impact of EU carbon border regulation mechanism(CBAM)on the export of China’s carbon-intensive products.First,we summarized the main content of the CBAM.Next,based on the input-outpu...This study analyzes the potential impact of EU carbon border regulation mechanism(CBAM)on the export of China’s carbon-intensive products.First,we summarized the main content of the CBAM.Next,based on the input-output theory,this study proposes a calculation model for the implicit carbon emissions and indirect carbon emissions from electricity consumption in export products and presents the corresponding calculation results.Based on the scenario analysis method,six carbon tariffscenarios were designed to evaluate the impact of the CBAM on the major export sectors under each scenario.The results showed that in 2021,the implicit carbon emissions in all products exported to Europe from China were approximately 375 million tons,of which the indirect carbon emissions from electricity were approximately 41.8 million tons,accounting for more than 10%.According to the current levy plan,China is expected to be subject to carbon tariffs of approximately USD 1.4 billion,accounting for 0.3%of its total export value to Europe in 2021.Finally,to reduce the adverse effects of CBAM,four measures were proposed from the perspective of the power industry.展开更多
It is increasingly relevant to study the effects of climate change on species habitats. Using a maximum entropy model, 22 environmental factors with significant effects on sorghum habitat distribution in China were se...It is increasingly relevant to study the effects of climate change on species habitats. Using a maximum entropy model, 22 environmental factors with significant effects on sorghum habitat distribution in China were selected to predict the potential habitat distribution of sorghum in China. The potential distribution of sorghum under baseline climate conditions and future climate conditions (2050s and 2070s) under two climate change scenarios, RCP4.5 and RCP8.5, were simulated, and the receiver operating curve under the accuracy of the model was evaluated using the area under the receiver operating curve (AUC). The results showed that the maximum entropy model predicted the potential sorghum habitat distribution with high accuracy, with Bio2 (monthly mean diurnal temperature difference), Bio6 (minimum temperature in the coldest month), and Bio13 (rainfall in the wettest month) as the main climatic factors affecting sorghum distribution among the 22 environmental factors. Under the baseline climate conditions, potential sorghum habitats are mainly distributed in the southwest, central, and east China. Over time, the potential sorghum habitat expanded into northern and southern China, with significant additions and negligible decreases in potential sorghum habitat in the study area, and a significant increase in total area, with the RCP8.5 scenario adding much more area than the RCP4.5 scenario.展开更多
Recent clinical trials have demonstrated a protective effect in using traditional Chinese medicine Tongxinluo(TXL)capsule to treat atherosclerosis.However,clinical evidence of the effects of TXL treatment on coronary ...Recent clinical trials have demonstrated a protective effect in using traditional Chinese medicine Tongxinluo(TXL)capsule to treat atherosclerosis.However,clinical evidence of the effects of TXL treatment on coronary plaque vulnerability is unavailable.In response,we developed this study to investigate the hypothesis that on the basis of statin therapy,treatment with TXL capsule may stabilize coronary lesions in patients with acute coronary syndrome(ACS).The TXL-CAP study was an investigator-initiated,randomized,double-blind clinical trial conducted across 18 medical centers in China.Patients with ACS aging from 18 to 80 years old who had a non-intervened coronary target lesion with a fibrous cap thickness(FCT)<100μm and lipid arc>90°as defined by optical coherence tomography(OCT)were recruited.A total of 220 patients who met the selection criteria but did not meet the exclusion criteria will be finally recruited and randomized to receive treatment with TXL(n=110)or placebo(n=110)for a duration of 12 months.The primary endpoint was the difference in the minimum FCT of the coronary target lesion between TXL and placebo groups at the end of the 12-month follow-up.Secondary endpoints included:(1)changes of the maximum lipid arc and length of the target plaque,and the percentage of lipid,fibrous,and calcified plaques at the end of the12-month period;(2)the incidence of composite cardiovascular events and coronary revascularization within the 12 months;(3)changes in the grade and scores of the angina pectoris as assessed using the Canadian Cardiovascular Society(CCS)grading system and Seattle angina questionnaire(SAQ)score,respectively;and(4)changes in hs-CRP serum levels.The results of the TXLCAP trial will provide additional clinical data for revealing whether TXL capsules stabilizes coronary vulnerable plaques in Chinese ACS patients.展开更多
BACKGROUND Colon adenocarcinoma(COAD)ranks second in terms of cancer-related deaths.We found that fatty acid-binding protein 4(FABP4),which is related to cell adhesion and immunity,affects the occurrence and developme...BACKGROUND Colon adenocarcinoma(COAD)ranks second in terms of cancer-related deaths.We found that fatty acid-binding protein 4(FABP4),which is related to cell adhesion and immunity,affects the occurrence and development of COAD.This study focused on the possibility of using FABP4 as a biomarker for COAD and constructed a nomogram for predicting the survival of COAD patients.AIM To verify the possibility of using FABP4 as a biomarker for COAD.METHODS A total of 453 COAD tissue samples,along with 41 normal tissue samples,were obtained from The Cancer Genome Atlas database.The difference in FABP4 expression between COAD tissues and normal tissues was analyzed,and the results were verified by immunohistochemistry.The WGCNA algorithm links FABP4 expression with an enrichment analysis and with immune cell infiltration pathways.The biological functions of FABP4 and its coexpressed genes were explored through enrichment analyses.The ESTIMATE,CIBERSORT and ssGSEA methods were used for the immune infiltration analysis.Finally,risk scores were calculated by a Cox analysis.A nomogram was constructed by combining risk scores with routine clinicopathological factors.We assessed the accuracy of survival predictions based on the C-index.The C-index ranges from 0.5 to 1.0,and in general,a C-index value greater than 0.65 indicates a reasonable estimate.The results were validated using the Gene Expression Omnibus(GEO)database.RESULTS FABP4 was significantly differentially expressed in COAD.It is a promising auxiliary biomarker for screening and diagnosis.Enrichment analyses suggested that FABP4 may influence the invasion and progression of COAD through cell adhesion.The immunological analysis revealed that FABP4 expression in COAD was significantly positively correlated with immune cell infiltration.Moreover,a nomogram to predict the survival of COAD patients was successfully constructed by integrating the calculated risk scores of 15 candidate genes and routine clinicopathological factors.This nomogram could effectively predict 1-year,3-year,and 5-year survival(C-index=0.786)and was verified(C-index=0.73).CONCLUSION This study established FABP4 as an effective biomarker for screening,assisting in the diagnosis and determining the prognosis.展开更多
This paper investigates the impact of the model top and damping layer on the numerical simulation of tropical cyclones(TCs)and reveals the significant role of stratospheric gravity waves(SGWs).TCs can generate SGWs,wh...This paper investigates the impact of the model top and damping layer on the numerical simulation of tropical cyclones(TCs)and reveals the significant role of stratospheric gravity waves(SGWs).TCs can generate SGWs,which propagate upward and outward into the stratosphere.These SGWs can reach the damping layer,which is a consequence of the numerical scheme employed,where they can affect the tangential circulation through the dragging and forcing processes.In models with a higher top boundary,this tangential circulation develops far from the TC and has minimal direct impact on TC intensity.By comparison,in models with a lower top(e.g.,20 km),the damping layer is located just above the top of the TC.The SGW dragging in the damping layer and the consequent tangential force can thus induce ascent outside the eyewall,promote latent heat release,tilt the eyewall,and enlarge the inner-core radius.This process will reduce inner-core vorticity advection within the boundary layer,and eventually inhibits the intensification of the TC.This suggests that when the thickness of the damping layer is 5 km,the TC numerical model top height should be at least higher than 20 km to generate more accurate simulations.展开更多
The excellent strength-ductility combination of hetero-grained Mg alloys has been reported to stem from pronounced hetero-deformation induced(HDI)stress.This stress alters the internal stress state of various slip sys...The excellent strength-ductility combination of hetero-grained Mg alloys has been reported to stem from pronounced hetero-deformation induced(HDI)stress.This stress alters the internal stress state of various slip systems and triggers significant activity of non-basal slips.However,the HDI stress state of different slip systems,and the mechanisms underlying the selective activation between basal and non-basal slips remain unclear to date.This study develops a novel HDI stress partitioning framework that in-situ calculates the crystallographic parameters and geometrical information of each datapoint within grains,aiming to reveal the correlation between HDI stress partitioning on individual slip systems and localized deformation model in the case of bimodal-grained ZK60 alloy.The framework demonstrates that HDI stress shows a strong dependence on the density of geometrically necessary dislocations(GNDs)and slip-system-level grain size,while exhibiting a relatively weaker correlation with equivalent-circle size of the hetero-grains.Given the close relation between the stress partitioning and the physical parameters,the framework can accurately predict the single and multiple slip activity fields obtained from highresolution digital image correlation(HR-DIC).This holds even for slip systems with low Schmid factors,which are theoretically difficult to activate.Using this framework,it is found that HDI stress plays a more prominent role in diminishing the effective resolved shear stress(RSS)of basaland prismatic(i.e.,component)dislocations,while having a negligible effect on pyramidal<c+a>slips.Benefiting from the increased ratio of RSS_(<c+a>)/RSS_(),pyramidal<c+a>dislocations are extensively activated,leading to excellent strength-ductility combination in the bimodal-grained ZK60 alloy.展开更多
To enhance the efficiency of stochastic vibration analysis for the Train-Track-Bridge(TTB)coupled system,this paper proposes a prediction method based on a Genetic Algorithm-optimized Backpropagation(GA-BP)neural netw...To enhance the efficiency of stochastic vibration analysis for the Train-Track-Bridge(TTB)coupled system,this paper proposes a prediction method based on a Genetic Algorithm-optimized Backpropagation(GA-BP)neural network.First,initial track irregularity samples and random parameter sets of the Vehicle-Bridge System(VBS)are generated using the stochastic harmonic function method.Then,the stochastic dynamic responses corresponding to the sample sets are calculated using a developed stochastic vibration analysis model of the TTB system.The track irregularity data and vehicle-bridge random parameters are used as input variables,while the corresponding stochastic responses serve as output variables for training the BP neural network to construct the prediction model.Subsequently,the Genetic Algorithm(GA)is applied to optimize the BP neural network by considering the randomness in excitation and parameters of the TTB system,improving model accuracy.After optimization,the trained GA-BP model enables rapid and accurate prediction of vehicle-bridge responses.To validate the proposed method,predictions of vehicle-bridge responses under varying train speeds are compared with numerical simulation results.The findings demonstrate that the proposed method offers notable advantages in predicting the stochastic vibration response of high-speed railway TTB coupled systems.展开更多
Colon-targeted oral drug delivery systems are one of the most promising therapeutic strategies for alleviating and curing inflammatory bowel disease(IBD),but they still face challenges in successfully passing through ...Colon-targeted oral drug delivery systems are one of the most promising therapeutic strategies for alleviating and curing inflammatory bowel disease(IBD),but they still face challenges in successfully passing through the harsh gastrointestinal environment and intestinal mucus barrier.To overcome the gastrointestinal barriers for oral drug delivery mentioned above,a“spore-like”oral nanodrug delivery platform(Cur/COS/SC NPs)has been developed.Firstly,chitooligosaccharides(COS)are encapsulated on the surface of Curcumin nanoparticles(Cur NPs)to form carrier-free nanoparticles(Cur/COS NPs).Subsequently,inspired by the natural high resistance of spore coat(SC),SC is chosen as the“protective umbrella”to encapsulate Cur/COS NPs for precision targeted therapy of IBD.After oral administration,SC can effectively protect NPs through the rugged gastrointestinal environment and exhibit excellent intestinal mucus penetration characteristics.Moreover,the negatively-charged Cur/COS/SC NPs specifically target positivelycharged inflamed colon via electrostatic interactions.It is demonstrated that Cur/COS/SC NPs can promote the expression of tight junction proteins,inhibit aberrant activation of the Toll-like receptor 4/myeloid differentiation primary response gene 88/nuclear factor-κB(TLR4/MyD88/NF-κB)signaling pathway,and downregulate the levels of pro-inflammatory factors,exhibiting excellent anti-inflammatory effects.Notably,it is found that Cur/COS/SC NPs can significantly increase the richness and diversity of gut microbiota,and restore the homeostasis of gut microbiota by inhibiting pathogenic bacteria and promoting probiotics.Hence,Cur/COS/SC NPs provide a safe,efficient,and feasible new strategy for IBD treatment.展开更多
Based on the experimental data of Mn_(1)Co_(0.5)Cr_(0.5)O_(x)catalysts and the component transport model in computational fluid dynamics(CFD),a kinetic model for the standard NH_(3)-SCR(NH_(3)selective catalytic reduc...Based on the experimental data of Mn_(1)Co_(0.5)Cr_(0.5)O_(x)catalysts and the component transport model in computational fluid dynamics(CFD),a kinetic model for the standard NH_(3)-SCR(NH_(3)selective catalytic reduction)process was effectively established.The objective of the model development was to predict the denitrification reaction rate of the catalyst,which incorporates various factors such as the Arrhenius parameters(pre-exponential factor and activation energy),inertial resistance,viscous resistance,and surface-to-volume ratio.To verify the practicability of the model,simulation results were compared with actual experimental data.The effects of NH_(3),NO,O_(2)concentrations,and gas hourly space velocity(GHSV)on NO conversion were simulated and analyzed.Subsequently,the NO conversion prediction model was trained and established using a combination of numerical simulation results,backpropagation neural network,and genetic algorithm(BP-GA).Furthermore,the significance of the impact that various factors had on the denitrification activity of the catalyst was determined.展开更多
Industrial robot application(IRA)provides an opportunity for the low-carbon development of trade.This study focuses on the green revolution of manufacturing export trade,analyzes the mechanism by which IRA affects CO_...Industrial robot application(IRA)provides an opportunity for the low-carbon development of trade.This study focuses on the green revolution of manufacturing export trade,analyzes the mechanism by which IRA affects CO_(2) emissions embodied in manufacturing exports(CIE),and conducts an empirical test based on panel data from 37 countries from 2000 to 2019.This study found that first,IRA can significantly reduce CIE,but there is a U-shaped nexus between the two,which shows a rebound effect.Second,the heterogeneity test demonstrates that in com-parison to both the low-tech and high-tech sectors,IRA in the medium-tech industry can significantly reduce CIE;compared with the low-IRA sectors,the high-IRA sectors exhibit a more obvious reduction.In addition,IRA has a stronger effect on high-carbon-intensity areas.Third,the mechanism test shows that IRA mainly affects CIE through low-carbon technology and productivity effects.Moreover,environmental regulations and the manufacturing in-telligence process positively moderate the nexus between IRA and CIE.Finally,these conclusions provide possible empirical evidence for the smart evolution of the manufacturing industry and the green development of trade.展开更多
The absence of efficient ion transport pathways in composite solid-state electrolytes(CSEs)usually results in low ionic conductivity,which remains a great challenge for developing solid-state lithiummetal batteries(SL...The absence of efficient ion transport pathways in composite solid-state electrolytes(CSEs)usually results in low ionic conductivity,which remains a great challenge for developing solid-state lithiummetal batteries(SLMBs).Herein,we report achieving accelerated Li^(+)conduction in CSEs by a novel activation of the interfacial dipole layer.Polycationic ionic liquids and polyacrylonitrile with highly polar functional groups(-C≡N)are utilized to modulate the interfacial dipole layer in MOF-based CSEs,facilitating long-range pathways for the connectivity of Li^(+)conduction and enhancing rapid transport kinetics.The as-synthesized CSEs exhibit a high ionic conductivity of 0.59 mS cm^(-1)and a lithium transfer number of 0.85.The assembled SLMBs(Li/CSE/LiNi_(0.9)Co_(0.05)Mn_(0.05)O_(2))delivered a high-capacity retention of 88.7%with a minimal discharge voltage attenuation of 17.1 mV after 500 cycles(0.03 mV per cycle)at0.5 C.This work offers an effective approach to creating interpenetrating lithium-ion transport pathways with rapid ion transport kinetics for solid-state electrolytes,thereby advancing the development of solidstate lithium metal batteries.展开更多
The CNC machine tool is the fundamental equipment of the manufacturing industry,particularly in sectors where achieving high levels of accuracy is crucial.Geometric accuracy design is an important step in machine tool...The CNC machine tool is the fundamental equipment of the manufacturing industry,particularly in sectors where achieving high levels of accuracy is crucial.Geometric accuracy design is an important step in machine tool design and plays an essential role in determining the machining accuracy of the workpiece.Researchers have extensively studied methods to model,extract,optimize,and measure the geometric errors that affect the geometric accuracy of machine tools.This paper provides a comprehensive review of the state-of-the-art approaches and an overview of the latest research progress associated with geometric accuracy design in CNC machine tools.This paper explores the interrelated aspects of CNC machine tool accuracy design:modeling,analysis and optimization.Accuracy analysis,which includes geometric error modeling and sensitivity analysis,determines a machine tool’s output accuracy through its volumetric error model,given the known accuracy of its individual components.Conversely,accuracy allocation designs the accuracy of the machine tool components according to given output accuracy requirements to achieve optimization between the objectives of manufacturing cost,quality,reliability,and environmental impact.In addition to discussing design factors and evaluation methods,this paper outlines methods for verifying the accuracy of design results,aiming to provide a practical basis for ensuring that the designed accuracy is achieved.Finally,the challenges and future research directions in geometric accuracy design are highlighted.展开更多
To meet the evolving demands of aeroengine development,the structural and performance requirements for ceramic cores have become increasingly stringent.Vat photopolymerization 3D printing,owing to its moldless,fiexibl...To meet the evolving demands of aeroengine development,the structural and performance requirements for ceramic cores have become increasingly stringent.Vat photopolymerization 3D printing,owing to its moldless,fiexible manufacturing,and other advantages,demonstrates significant potential in the preparation of ceramic cores with intricate structures.However,its practical application still faces multiple challenges,including layered structures and property anisotropy,defects such as cracks and collapse during printing and sintering,forming inaccuracies,and difficulties in controlling surface roughness.Recent advances have focused on optimizing slurry formulation and rheology,improving curing behavior,introducing auxiliary powders and additives,tailoring forming parameters,and optimizing the sintering process.Nevertheless,effectively suppressing lamellar defects,achieving superior dimensional accuracy,and maintaining high surface quality in complex structures remain the core scientific and technical issues to be solved.Future research should concentrate on refining curing mechanisms,advancing powder design and organic system optimization,and regulating the coupled processes of forming,debinding,and sintering to accelerate the application of VPP 3D printed ceramic cores in aerospace manufacturing.展开更多
Devices in Industrial Internet of Things are vulnerable to voice adversarial attacks.Studying adversarial speech samples is crucial for enhancing the security of automatic speech recognition systems in Industrial Inte...Devices in Industrial Internet of Things are vulnerable to voice adversarial attacks.Studying adversarial speech samples is crucial for enhancing the security of automatic speech recognition systems in Industrial Internet of Things devices.Current black-box attack methods often face challenges such as complex search processes and excessive perturbation generation.To address these issues,this paper proposes a black-box voice adversarial attack method based on enhanced neural predictors.This method searches for minimal perturbations in the perturbation space,employing an optimization process guided by a self-attention neural predictor to identify the optimal perturbation direction.This direction is then applied to the original sample to generate adversarial samples.To improve search efficiency,a pruning strategy is designed to discard samples below a threshold in the early search stages,reducing the number of searches.Additionally,a dynamic factor based on feedback from querying the automatic speech recognition system is introduced to adaptively adjust the search step size,further accelerating the search process.To validate the performance of the proposed method,experiments are conducted on the LibriSpeech dataset.Compared with the mainstream methods,the proposed method improves the signal-to-noise ratio by 0.8 dB,increases sample similarity by 0.43%,and reduces the average number of queries by 7%.Experimental results demonstrate that the proposed method offers better attack effectiveness and stealthiness.展开更多
基金supported by the State Grid Corporation of China Science and Technology Project,grant number 52270723000900K.
文摘The new energy power generation is becoming increasingly important in the power system.Such as photovoltaic power generation has become a research hotspot,however,due to the characteristics of light radiation changes,photovoltaic power generation is unstable and random,resulting in a low utilization rate and directly affecting the stability of the power grid.To solve this problem,this paper proposes a coordinated control strategy for a newenergy power generation system with a hybrid energy storage unit based on the lithium iron phosphate-supercapacitor hybrid energy storage unit.Firstly,the variational mode decomposition algorithm is used to separate the high and low frequencies of the power signal,which is conducive to the rapid and accurate suppression of the power fluctuation of the energy storage system.Secondly,the fuzzy control algorithm is introduced to balance the power between energy storage.In this paper,the actual data is used for simulation,and the simulation results show that the strategy realizes the effective suppression of the bus voltage fluctuation and the accurate control of the internal state of the energy storage unit,effectively avoiding problems such as overshoot and over-discharge,and can significantly improve the stability of the photovoltaic power generation systemand the stability of the Direct Current bus.It is of great significance to promote the development of collaborative control technology for photovoltaic hybrid energy storage units.
文摘In this work,the combined addition of strontium/indium(Sr/In)to the magnesium anode for Mg-Air Cells is investigated to improve discharge performance by modifying the anode/electrolyte interface.Indium exists as solid solution atoms in theα-Mg matrix without its second-phase generation,and at the same time facilitates grain refinement,dendritic segregation and Mg17Sr2-phases precipitation.During discharge operation,Sr modifies the film composition via its compounds and promoted the redeposition of In at the substrate/film interface;their co-deposition behavior on the anodic reaction surface enhances anode reaction kinetics,suppresses the negative difference effect(NDE)and mitigates the“chunk effect”(CE),which is contributed to uniform dissolution and low self-corrosion hydrogen evolution rate(HER).Therefore,Mg-Sr-xIn alloy anodes show excellent discharge performance,e.g.,0.5Sr-1.0In shows an average discharge voltage of 1.4234 V and a specific energy density of 1990.71 Wh kg^(-1)at 10 mA cm^(-2).Furthermore,the decisive factor(CE and self-discharge HE)for anodic efficiency are quantitively analyzed,the self-discharge is the main factor of cell efficiency loss.Surprisingly,all Mg-Sr-xIn anodes show anodic efficiency greater than 60%at high current density(≥10 mA cm^(-2)),making them excellent candidate anodes for Mg-Air cells at high-power output.
基金supported by the National Key R&D Program of China 2022YFB2404300the National Natural Science Foundation of China U22B2069the China Postdoctoral Science Foundation 2024M761006。
文摘The reaction rate constant is a crucial kinetic parameter that governs the charge and discharge performance of batteries,particularly in high-rate and thick-electrode applications.However,conventional estimation or fitting methods often overestimate the charge transfer overpotential,leading to substantial errors in reaction rate constant measurements.These inaccuracies hinder the accurate prediction of voltage profiles and overall cell performance.In this study,we propose the characteristic time-decomposed overpotential(CTDO)method,which employs a single-layer particle electrode(SLPE)structure to eliminate interference overpotentials.By leveraging the distribution of relaxation times(DRT),our method effectively isolates the characteristic time of the charge transfer process,enabling a more precise determination of the reaction rate constant.Simulation results indicate that our approach reduces measurement errors to below 2%,closely aligning with theoretical values.Furthermore,experimental validation demonstrates an 80% reduction in error compared to the conventional galvanostatic intermittent titration technique(GITT)method.Overall,this study provides a novel voltage-based approach for determining the reaction rate constant,enhancing the applicability of theoretical analysis in electrode structural design and facilitating rapid battery optimization.
基金National Key R&D Program of China,Grant/Award Number:2023YFB2503900National Natural Science Foundation of China,Grant/Award Number:12172143Shenzhen Science and Technology Program,Grant/Award Numbers:JCYJ20220818100418040,JCYJ20220530160816038。
文摘Constructing silicon(Si)-based composite electrodes that possess high energy density,long cycle life,and fast charging capability simultaneously is critical for the development of high performance lithium-ion batteries for mitigating range anxiety and slow charging issues in new energy vehicles.Herein,a thick silicon/carbon composite electrode with vertically aligned channels in the thickness direction(VC-SC)is constructed by employing a bubble formation method.Both experimental characterizations and theoretical simulations confirm that the obtained vertical channel structure can effectively address the problem of sluggish ion transport caused by high tortuosity in conventional thick electrodes,conspicuously enhance reaction kinetics,reduce polarization and side reactions,mitigate stress,increase the utilization of active materials,and promote cycling stability of the thick electrode.Consequently,when paired with LiNi_(0.6)Co_(0.2)Mn_(0.2)O_(2)(NCM622),the VC-SC||NCM622 pouch type full cell(~6.0 mAh cm^(-2))exhibits significantly improved rate performance and capacity retention compared with the SC||NCM622 full cell with the conventional silicon/carbon composite electrode without channels(SC)as the anode.The assembled VC-SC||NCM622 pouch full cell with a high energy density of 490.3 Wh kg^(-1)also reveals a remarkable fast charging capability at a high current density of 2.0 mA cm^(-2),with a capacity retention of 72.0%after 500 cycles.
文摘This study analyzes the potential impact of EU carbon border regulation mechanism(CBAM)on the export of China’s carbon-intensive products.First,we summarized the main content of the CBAM.Next,based on the input-output theory,this study proposes a calculation model for the implicit carbon emissions and indirect carbon emissions from electricity consumption in export products and presents the corresponding calculation results.Based on the scenario analysis method,six carbon tariffscenarios were designed to evaluate the impact of the CBAM on the major export sectors under each scenario.The results showed that in 2021,the implicit carbon emissions in all products exported to Europe from China were approximately 375 million tons,of which the indirect carbon emissions from electricity were approximately 41.8 million tons,accounting for more than 10%.According to the current levy plan,China is expected to be subject to carbon tariffs of approximately USD 1.4 billion,accounting for 0.3%of its total export value to Europe in 2021.Finally,to reduce the adverse effects of CBAM,four measures were proposed from the perspective of the power industry.
文摘It is increasingly relevant to study the effects of climate change on species habitats. Using a maximum entropy model, 22 environmental factors with significant effects on sorghum habitat distribution in China were selected to predict the potential habitat distribution of sorghum in China. The potential distribution of sorghum under baseline climate conditions and future climate conditions (2050s and 2070s) under two climate change scenarios, RCP4.5 and RCP8.5, were simulated, and the receiver operating curve under the accuracy of the model was evaluated using the area under the receiver operating curve (AUC). The results showed that the maximum entropy model predicted the potential sorghum habitat distribution with high accuracy, with Bio2 (monthly mean diurnal temperature difference), Bio6 (minimum temperature in the coldest month), and Bio13 (rainfall in the wettest month) as the main climatic factors affecting sorghum distribution among the 22 environmental factors. Under the baseline climate conditions, potential sorghum habitats are mainly distributed in the southwest, central, and east China. Over time, the potential sorghum habitat expanded into northern and southern China, with significant additions and negligible decreases in potential sorghum habitat in the study area, and a significant increase in total area, with the RCP8.5 scenario adding much more area than the RCP4.5 scenario.
基金National Key Research and Development Program of China(2017YFC1700502)Ministry of Science and Technology of China。
文摘Recent clinical trials have demonstrated a protective effect in using traditional Chinese medicine Tongxinluo(TXL)capsule to treat atherosclerosis.However,clinical evidence of the effects of TXL treatment on coronary plaque vulnerability is unavailable.In response,we developed this study to investigate the hypothesis that on the basis of statin therapy,treatment with TXL capsule may stabilize coronary lesions in patients with acute coronary syndrome(ACS).The TXL-CAP study was an investigator-initiated,randomized,double-blind clinical trial conducted across 18 medical centers in China.Patients with ACS aging from 18 to 80 years old who had a non-intervened coronary target lesion with a fibrous cap thickness(FCT)<100μm and lipid arc>90°as defined by optical coherence tomography(OCT)were recruited.A total of 220 patients who met the selection criteria but did not meet the exclusion criteria will be finally recruited and randomized to receive treatment with TXL(n=110)or placebo(n=110)for a duration of 12 months.The primary endpoint was the difference in the minimum FCT of the coronary target lesion between TXL and placebo groups at the end of the 12-month follow-up.Secondary endpoints included:(1)changes of the maximum lipid arc and length of the target plaque,and the percentage of lipid,fibrous,and calcified plaques at the end of the12-month period;(2)the incidence of composite cardiovascular events and coronary revascularization within the 12 months;(3)changes in the grade and scores of the angina pectoris as assessed using the Canadian Cardiovascular Society(CCS)grading system and Seattle angina questionnaire(SAQ)score,respectively;and(4)changes in hs-CRP serum levels.The results of the TXLCAP trial will provide additional clinical data for revealing whether TXL capsules stabilizes coronary vulnerable plaques in Chinese ACS patients.
基金Supported by the University Scientific Research Project of Anhui Province,No.2024AH051916the Quality Engineering Project of Anhui Province,No.2022sx159 and No.2022sdxx031the Key Research and Development Project of Anhui Province,No.2022e07020036.
文摘BACKGROUND Colon adenocarcinoma(COAD)ranks second in terms of cancer-related deaths.We found that fatty acid-binding protein 4(FABP4),which is related to cell adhesion and immunity,affects the occurrence and development of COAD.This study focused on the possibility of using FABP4 as a biomarker for COAD and constructed a nomogram for predicting the survival of COAD patients.AIM To verify the possibility of using FABP4 as a biomarker for COAD.METHODS A total of 453 COAD tissue samples,along with 41 normal tissue samples,were obtained from The Cancer Genome Atlas database.The difference in FABP4 expression between COAD tissues and normal tissues was analyzed,and the results were verified by immunohistochemistry.The WGCNA algorithm links FABP4 expression with an enrichment analysis and with immune cell infiltration pathways.The biological functions of FABP4 and its coexpressed genes were explored through enrichment analyses.The ESTIMATE,CIBERSORT and ssGSEA methods were used for the immune infiltration analysis.Finally,risk scores were calculated by a Cox analysis.A nomogram was constructed by combining risk scores with routine clinicopathological factors.We assessed the accuracy of survival predictions based on the C-index.The C-index ranges from 0.5 to 1.0,and in general,a C-index value greater than 0.65 indicates a reasonable estimate.The results were validated using the Gene Expression Omnibus(GEO)database.RESULTS FABP4 was significantly differentially expressed in COAD.It is a promising auxiliary biomarker for screening and diagnosis.Enrichment analyses suggested that FABP4 may influence the invasion and progression of COAD through cell adhesion.The immunological analysis revealed that FABP4 expression in COAD was significantly positively correlated with immune cell infiltration.Moreover,a nomogram to predict the survival of COAD patients was successfully constructed by integrating the calculated risk scores of 15 candidate genes and routine clinicopathological factors.This nomogram could effectively predict 1-year,3-year,and 5-year survival(C-index=0.786)and was verified(C-index=0.73).CONCLUSION This study established FABP4 as an effective biomarker for screening,assisting in the diagnosis and determining the prognosis.
基金supported by the National Natural Science Foundation of China(Grant Nos.42475016,42192555 and 42305085)the China Postdoctoral Science Foundation(Grant No.2023M741615)the 2023 Graduate Research Innovation Project of Hunan Province(Grant No.CX20230011)。
文摘This paper investigates the impact of the model top and damping layer on the numerical simulation of tropical cyclones(TCs)and reveals the significant role of stratospheric gravity waves(SGWs).TCs can generate SGWs,which propagate upward and outward into the stratosphere.These SGWs can reach the damping layer,which is a consequence of the numerical scheme employed,where they can affect the tangential circulation through the dragging and forcing processes.In models with a higher top boundary,this tangential circulation develops far from the TC and has minimal direct impact on TC intensity.By comparison,in models with a lower top(e.g.,20 km),the damping layer is located just above the top of the TC.The SGW dragging in the damping layer and the consequent tangential force can thus induce ascent outside the eyewall,promote latent heat release,tilt the eyewall,and enlarge the inner-core radius.This process will reduce inner-core vorticity advection within the boundary layer,and eventually inhibits the intensification of the TC.This suggests that when the thickness of the damping layer is 5 km,the TC numerical model top height should be at least higher than 20 km to generate more accurate simulations.
基金the National Natural Science Foundation of China(No.52305385,U23A20541,52471131,52201057)the University Natural Science Research Project of Anhui Province(No.2022AH050316).
文摘The excellent strength-ductility combination of hetero-grained Mg alloys has been reported to stem from pronounced hetero-deformation induced(HDI)stress.This stress alters the internal stress state of various slip systems and triggers significant activity of non-basal slips.However,the HDI stress state of different slip systems,and the mechanisms underlying the selective activation between basal and non-basal slips remain unclear to date.This study develops a novel HDI stress partitioning framework that in-situ calculates the crystallographic parameters and geometrical information of each datapoint within grains,aiming to reveal the correlation between HDI stress partitioning on individual slip systems and localized deformation model in the case of bimodal-grained ZK60 alloy.The framework demonstrates that HDI stress shows a strong dependence on the density of geometrically necessary dislocations(GNDs)and slip-system-level grain size,while exhibiting a relatively weaker correlation with equivalent-circle size of the hetero-grains.Given the close relation between the stress partitioning and the physical parameters,the framework can accurately predict the single and multiple slip activity fields obtained from highresolution digital image correlation(HR-DIC).This holds even for slip systems with low Schmid factors,which are theoretically difficult to activate.Using this framework,it is found that HDI stress plays a more prominent role in diminishing the effective resolved shear stress(RSS)of basaland prismatic(i.e.,component)dislocations,while having a negligible effect on pyramidal<c+a>slips.Benefiting from the increased ratio of RSS_(<c+a>)/RSS_(),pyramidal<c+a>dislocations are extensively activated,leading to excellent strength-ductility combination in the bimodal-grained ZK60 alloy.
基金supported by the China State Railway Group Co.,Ltd.Science and Technology Research and Development Program Project(Grant No.L2024G007)the Natural Science Foundation of Hunan Province(Grant No.2024JJ5427)+1 种基金the National Natural Science Foundation of China(Grant No.52478321,52078485)the Science and Technology Research and Development Program Project of China Railway Group Limited(Grant No.2021-Special-08,2022-Key-06&2023-Key-22).
文摘To enhance the efficiency of stochastic vibration analysis for the Train-Track-Bridge(TTB)coupled system,this paper proposes a prediction method based on a Genetic Algorithm-optimized Backpropagation(GA-BP)neural network.First,initial track irregularity samples and random parameter sets of the Vehicle-Bridge System(VBS)are generated using the stochastic harmonic function method.Then,the stochastic dynamic responses corresponding to the sample sets are calculated using a developed stochastic vibration analysis model of the TTB system.The track irregularity data and vehicle-bridge random parameters are used as input variables,while the corresponding stochastic responses serve as output variables for training the BP neural network to construct the prediction model.Subsequently,the Genetic Algorithm(GA)is applied to optimize the BP neural network by considering the randomness in excitation and parameters of the TTB system,improving model accuracy.After optimization,the trained GA-BP model enables rapid and accurate prediction of vehicle-bridge responses.To validate the proposed method,predictions of vehicle-bridge responses under varying train speeds are compared with numerical simulation results.The findings demonstrate that the proposed method offers notable advantages in predicting the stochastic vibration response of high-speed railway TTB coupled systems.
基金supported by the National Natural Science Foundation of China(Nos.82272847,82304417,82303529,82171333)China Postdoctoral Science Foundation(Nos.2023TQ0307,2023M743231,2023M730971)+2 种基金Science and Technology Project of Henan Province(No.242102311204)Postdoctoral Fellowship Program of CPSF(No.GZB20230675)Modern Analysis and Computer Center of Zhengzhou University.
文摘Colon-targeted oral drug delivery systems are one of the most promising therapeutic strategies for alleviating and curing inflammatory bowel disease(IBD),but they still face challenges in successfully passing through the harsh gastrointestinal environment and intestinal mucus barrier.To overcome the gastrointestinal barriers for oral drug delivery mentioned above,a“spore-like”oral nanodrug delivery platform(Cur/COS/SC NPs)has been developed.Firstly,chitooligosaccharides(COS)are encapsulated on the surface of Curcumin nanoparticles(Cur NPs)to form carrier-free nanoparticles(Cur/COS NPs).Subsequently,inspired by the natural high resistance of spore coat(SC),SC is chosen as the“protective umbrella”to encapsulate Cur/COS NPs for precision targeted therapy of IBD.After oral administration,SC can effectively protect NPs through the rugged gastrointestinal environment and exhibit excellent intestinal mucus penetration characteristics.Moreover,the negatively-charged Cur/COS/SC NPs specifically target positivelycharged inflamed colon via electrostatic interactions.It is demonstrated that Cur/COS/SC NPs can promote the expression of tight junction proteins,inhibit aberrant activation of the Toll-like receptor 4/myeloid differentiation primary response gene 88/nuclear factor-κB(TLR4/MyD88/NF-κB)signaling pathway,and downregulate the levels of pro-inflammatory factors,exhibiting excellent anti-inflammatory effects.Notably,it is found that Cur/COS/SC NPs can significantly increase the richness and diversity of gut microbiota,and restore the homeostasis of gut microbiota by inhibiting pathogenic bacteria and promoting probiotics.Hence,Cur/COS/SC NPs provide a safe,efficient,and feasible new strategy for IBD treatment.
基金supported by Science and Technology Research Project of Henan Province(242102230078)Key Research Project of Higher Education Institutions of Henan Province(23A470002)Innovative Research Team of Henan Polytechnic University(T2020-3).
文摘Based on the experimental data of Mn_(1)Co_(0.5)Cr_(0.5)O_(x)catalysts and the component transport model in computational fluid dynamics(CFD),a kinetic model for the standard NH_(3)-SCR(NH_(3)selective catalytic reduction)process was effectively established.The objective of the model development was to predict the denitrification reaction rate of the catalyst,which incorporates various factors such as the Arrhenius parameters(pre-exponential factor and activation energy),inertial resistance,viscous resistance,and surface-to-volume ratio.To verify the practicability of the model,simulation results were compared with actual experimental data.The effects of NH_(3),NO,O_(2)concentrations,and gas hourly space velocity(GHSV)on NO conversion were simulated and analyzed.Subsequently,the NO conversion prediction model was trained and established using a combination of numerical simulation results,backpropagation neural network,and genetic algorithm(BP-GA).Furthermore,the significance of the impact that various factors had on the denitrification activity of the catalyst was determined.
基金the National Social Science Foundation of China(Grant No.23FGLB024)Special Project on“Promoting High-Quality Development through the Integration of the Yangtze River Delta”of Shaoxing University(Grant No.2024CSJYB01)to provide fund for the study。
文摘Industrial robot application(IRA)provides an opportunity for the low-carbon development of trade.This study focuses on the green revolution of manufacturing export trade,analyzes the mechanism by which IRA affects CO_(2) emissions embodied in manufacturing exports(CIE),and conducts an empirical test based on panel data from 37 countries from 2000 to 2019.This study found that first,IRA can significantly reduce CIE,but there is a U-shaped nexus between the two,which shows a rebound effect.Second,the heterogeneity test demonstrates that in com-parison to both the low-tech and high-tech sectors,IRA in the medium-tech industry can significantly reduce CIE;compared with the low-IRA sectors,the high-IRA sectors exhibit a more obvious reduction.In addition,IRA has a stronger effect on high-carbon-intensity areas.Third,the mechanism test shows that IRA mainly affects CIE through low-carbon technology and productivity effects.Moreover,environmental regulations and the manufacturing in-telligence process positively moderate the nexus between IRA and CIE.Finally,these conclusions provide possible empirical evidence for the smart evolution of the manufacturing industry and the green development of trade.
基金financially supported by the National Natural Science Foundation of China(22408239)the National Natural Science Foundation of China(51904193)+3 种基金the Sichuan Science and Technology Program(2024NSFSC0987)the Fundamental Research Funds for the Central Universities(No.YJ202280)support from the Australian Research Council(ARC)through the ARC Linkage project(LP200200926)ARC Discover project(DP240102176)。
文摘The absence of efficient ion transport pathways in composite solid-state electrolytes(CSEs)usually results in low ionic conductivity,which remains a great challenge for developing solid-state lithiummetal batteries(SLMBs).Herein,we report achieving accelerated Li^(+)conduction in CSEs by a novel activation of the interfacial dipole layer.Polycationic ionic liquids and polyacrylonitrile with highly polar functional groups(-C≡N)are utilized to modulate the interfacial dipole layer in MOF-based CSEs,facilitating long-range pathways for the connectivity of Li^(+)conduction and enhancing rapid transport kinetics.The as-synthesized CSEs exhibit a high ionic conductivity of 0.59 mS cm^(-1)and a lithium transfer number of 0.85.The assembled SLMBs(Li/CSE/LiNi_(0.9)Co_(0.05)Mn_(0.05)O_(2))delivered a high-capacity retention of 88.7%with a minimal discharge voltage attenuation of 17.1 mV after 500 cycles(0.03 mV per cycle)at0.5 C.This work offers an effective approach to creating interpenetrating lithium-ion transport pathways with rapid ion transport kinetics for solid-state electrolytes,thereby advancing the development of solidstate lithium metal batteries.
基金Supported by the National Natural Science Foundation of China(Grant Nos.52375448,52275440).
文摘The CNC machine tool is the fundamental equipment of the manufacturing industry,particularly in sectors where achieving high levels of accuracy is crucial.Geometric accuracy design is an important step in machine tool design and plays an essential role in determining the machining accuracy of the workpiece.Researchers have extensively studied methods to model,extract,optimize,and measure the geometric errors that affect the geometric accuracy of machine tools.This paper provides a comprehensive review of the state-of-the-art approaches and an overview of the latest research progress associated with geometric accuracy design in CNC machine tools.This paper explores the interrelated aspects of CNC machine tool accuracy design:modeling,analysis and optimization.Accuracy analysis,which includes geometric error modeling and sensitivity analysis,determines a machine tool’s output accuracy through its volumetric error model,given the known accuracy of its individual components.Conversely,accuracy allocation designs the accuracy of the machine tool components according to given output accuracy requirements to achieve optimization between the objectives of manufacturing cost,quality,reliability,and environmental impact.In addition to discussing design factors and evaluation methods,this paper outlines methods for verifying the accuracy of design results,aiming to provide a practical basis for ensuring that the designed accuracy is achieved.Finally,the challenges and future research directions in geometric accuracy design are highlighted.
基金supported by the National Key R&D Program of China(Grant Nos.2024YFB3714502,2024YFB3714501,2024YFB3714504)the National Natural Science Foundation of China(Grant Nos.52130204,52174376)+5 种基金the TQ Innovation Foundation(Grant No.23-TQ09-02-ZT-01-005)the Aeronautical Science Foundation of China(Grant No.20220042053001)the Ningbo Science and Technology Plan Project(Grant No.2025Z070)the Key R&D Project of Shaanxi Province(Grant Nos2024GX-YBXM-220,2024CY-GJHX-29,2024GX-ZDCYL-03-03,2024GX-YBXM-400)the National Advanced Rare Metal Materials Innovation Center Project[Grant No.2024 ZG-GCZX-01(1)-01]the Foundation of China Scholarship Council(Grant No.202406290136)。
文摘To meet the evolving demands of aeroengine development,the structural and performance requirements for ceramic cores have become increasingly stringent.Vat photopolymerization 3D printing,owing to its moldless,fiexible manufacturing,and other advantages,demonstrates significant potential in the preparation of ceramic cores with intricate structures.However,its practical application still faces multiple challenges,including layered structures and property anisotropy,defects such as cracks and collapse during printing and sintering,forming inaccuracies,and difficulties in controlling surface roughness.Recent advances have focused on optimizing slurry formulation and rheology,improving curing behavior,introducing auxiliary powders and additives,tailoring forming parameters,and optimizing the sintering process.Nevertheless,effectively suppressing lamellar defects,achieving superior dimensional accuracy,and maintaining high surface quality in complex structures remain the core scientific and technical issues to be solved.Future research should concentrate on refining curing mechanisms,advancing powder design and organic system optimization,and regulating the coupled processes of forming,debinding,and sintering to accelerate the application of VPP 3D printed ceramic cores in aerospace manufacturing.
基金supported in part by the Natural Science Foundation of China under Grant 62273272,Grant 62303375,and Grant 61873277in part by the Key Research and Development Program of Shaanxi Province under Grant 2024CY2-GJHX-49 and Grant 2024CY2-GJHX-43+1 种基金in part by the Youth Innovation Team of Shaanxi Universitiesand in part by the Key Scientific Research Programof Education Department of Shaanxi Province under Grant 24JR111.
文摘Devices in Industrial Internet of Things are vulnerable to voice adversarial attacks.Studying adversarial speech samples is crucial for enhancing the security of automatic speech recognition systems in Industrial Internet of Things devices.Current black-box attack methods often face challenges such as complex search processes and excessive perturbation generation.To address these issues,this paper proposes a black-box voice adversarial attack method based on enhanced neural predictors.This method searches for minimal perturbations in the perturbation space,employing an optimization process guided by a self-attention neural predictor to identify the optimal perturbation direction.This direction is then applied to the original sample to generate adversarial samples.To improve search efficiency,a pruning strategy is designed to discard samples below a threshold in the early search stages,reducing the number of searches.Additionally,a dynamic factor based on feedback from querying the automatic speech recognition system is introduced to adaptively adjust the search step size,further accelerating the search process.To validate the performance of the proposed method,experiments are conducted on the LibriSpeech dataset.Compared with the mainstream methods,the proposed method improves the signal-to-noise ratio by 0.8 dB,increases sample similarity by 0.43%,and reduces the average number of queries by 7%.Experimental results demonstrate that the proposed method offers better attack effectiveness and stealthiness.
