Dear Editor,We read with a great interest the recently published systematic review by Shamsikhani and Hosseini titled,“Foot reflexology on nausea and vomiting:A systematic review.”[1]While the authors provided a com...Dear Editor,We read with a great interest the recently published systematic review by Shamsikhani and Hosseini titled,“Foot reflexology on nausea and vomiting:A systematic review.”[1]While the authors provided a comprehensive qualitative synthesis of six studies meeting their inclusion criteria,we believe that additional quantitative analysis would strengthen the evidence base for foot reflexology in managing nausea and vomiting.We conducted a complementary meta-analysis to provide quantitative evidence supporting the qualitative findings presented in the systematic review.展开更多
Cryptocurrency,a booming decentralised asset designed based on the blockchain architecture,is particularly important to the market at the present time by studying the volatility risk of cryptocurrencies.In this paper,...Cryptocurrency,a booming decentralised asset designed based on the blockchain architecture,is particularly important to the market at the present time by studying the volatility risk of cryptocurrencies.In this paper,we empirically analyse the volatility risk of cryptocurrencies through quantitative analysis models,comprehensively using the Markov state transition GARCH model with skewed distribution(Skew-MSGARCH)and the autoregressive conditional volatility density ARJI model introducing the Poisson jump factor,and selecting the earliest developed and the most mature currency price volatility daily return series,to deeply explore the volatility risk of digital cryptocurrencies.risk.Finally,it can be seen through in-depth analyses that the expectation factor and information inducement are the main reasons leading to the exacerbation of the volatility risk of digital cryptocurrencies.It is recommended that this situation be optimised and improved in terms of the value function of digital cryptocurrencies themselves and the implementation of systematic risk management and regulatory innovation.As an important component of the digital economy,blockchain technology can effectively regulate and improve the volatility of digital cryptocurrencies under macroeconomic policies,thereby maintaining the security and stability of emerging financial markets.展开更多
Objective To quantitatively analyze the policy of centralized drug procurement centralized drug procurement in order to provide reference for the subsequent policy formulation and improvement.Methods Text mining metho...Objective To quantitatively analyze the policy of centralized drug procurement centralized drug procurement in order to provide reference for the subsequent policy formulation and improvement.Methods Text mining method was used to process 15 centralized drugs procurement policies issued at the national level during 2015-2022,and a PMC index evaluation model of centralized drug procurement policies was established.Then,15 centralized drug procurement policies were quantitatively analyzed from the overall and comparative perspective through an evaluation model.Results and Conclusion The average PMC index of 15 centralized drug procurement policies was 6.95,which was acceptable on the whole.Among them,eight were excellent and seven were acceptable.As to the first-order variables,the centralized drugs procurement policy still lacks incentives and constraints.The comparative results show that there are differences in the content and structure of policies,but they are strongly related to each other.Chinese centralized drug procurement policy has been basically formed,which is closely related to medical insurance and medical policies.However,it is still necessary to pay attention to the structure of the policy to ensure the elaboration of the policy content.展开更多
Optimization and simplification of optical systems represent a milestone in advancing the development of handheld and portable laser-induced breakdown spectroscopy(LIBS)systems towards smaller,more integrated forms.Th...Optimization and simplification of optical systems represent a milestone in advancing the development of handheld and portable laser-induced breakdown spectroscopy(LIBS)systems towards smaller,more integrated forms.This research,for the first time,conducted a comprehensive optimization design and comparative analysis of three compact LIBS system optical paths:the paraxial optical path(OP),the off-axis OP,and the reflective OP.The differences in spectral intensity and stability among these paths were revealed,providing a scientific basis for selecting the optimal OP for LIBS systems.The research found that the paraxial OP excels in spectral performance and quantitative analysis accuracy,making it the preferred choice for compact LIBS systems.Specifically,the paraxial OP significantly enhances spectral intensity,achieving a 6 times improvement over the off-axis OP and an even more remarkable 150 times increase compared to the reflective OP,greatly enhancing detection sensitivity.Additionally,the relative standard deviation,spectral stability index,maintains a consistently low level,ranging from 10.9%to 13.4%,significantly outperforming the other two OPs and ensuring the reliability of analytical results.In the field of quantitative analysis,the paraxial OP also demonstrates higher accuracy,precision,and sensitivity,comparing to other OPs.The quantitative analysis models for Si,Cu,and Ti elements exhibit excellent fitting,providing users with high-quality quantitative analysis results that are of great significance for applications in material science,environmental monitoring,industrial inspection,and other fields.In summary,this study not only confirms the enormous application potential of the paraxial OP in compact LIBS systems but also provides valuable practical experience and theoretical support for the miniaturization and integration of LIBS systems.Looking ahead,with continuous technological advancements,the design of the paraxial OP is expected to further propel the widespread adoption of LIBS technology in portable,on-site detection applications.展开更多
Aero engines are key power components that provide thrust for the aircraft.The cerme turbine disc allows the new-generation domestic fighter aircraft to increase the overall thrust of the aero engine.Quantifying coati...Aero engines are key power components that provide thrust for the aircraft.The cerme turbine disc allows the new-generation domestic fighter aircraft to increase the overall thrust of the aero engine.Quantifying coatings and analyzing the stress on the teeth play critical roles in improving the turbine disc’s performance,which are two issues must be solved urgently.First,this work pro poses a quantitative analysis algorithm to conduct the Three-Dimensional(3D)distribution informa tion mining of the extracted coatings.Then,it proposes an Industrial Computed Laminography(ICL)reconstruction algorithm for non-destructively reconstructing the turbine disc’s high-quality3D morphological actual feature.Finally,a Finite Element Analysis(FEA)under the ultimate thrus is conducted on ICL reconstruction to verify the working status of the new-generation aero-engine turbine disc.The results show that the proposed quantitative analysis algorithm digitizes the aggre gated conditions of the coating with a statistically normalized Z_(1)value of–2.15 and a confidence leve higher than 95%.Three image-quality quantitative indicators:Peak Signal-to-Noise Ratio(PSNR)Structural Similarity Index Measure(SSIM),and Normalized Mean Square Distance(NMSD)of the proposed ICL reconstruction algorithm on turbine disc laminographic image are 26.45,0.88,and 0.73respectively,which are better than other algorithms.The mechanical analysis of ICL more realisti cally reflects the stress and deformation than that of 3D modeling.This work provides new ideas for the iterative research of new-generation aero-engine turbine discs.展开更多
Three-dimensional printing(3DP)offers valuable insight into the characterization of natural rocks and the verification of theoretical models due to its high reproducibility and accurate replication of complex defects ...Three-dimensional printing(3DP)offers valuable insight into the characterization of natural rocks and the verification of theoretical models due to its high reproducibility and accurate replication of complex defects such as cracks and pores.In this study,3DP gypsum samples with different printing directions were subjected to a series of uniaxial compression tests with in situ micro-computed tomography(micro-CT)scanning to quantitatively investigate their mechanical anisotropic properties and damage evolution characteristics.Based on the two-dimensional(2D)CT images obtained at different scanning steps,a novel void ratio variable was derived using the mean value and variance of CT intensity.Additionally,a constitutive model was formulated incorporating the proposed damage variable,utilizing the void ratio variable.The crack evolution and crack morphology of 3DP gypsum samples were obtained and analyzed using the 3D models reconstructed from the CT images.The results indicate that 3DP gypsum samples exhibit mechanical anisotropic characteristics similar to those found in naturally sedimentary rocks.The mechanical anisotropy is attributed to the bedding planes formed between adjacent layers and pillar-like structures along the printing direction formed by CaSO_(4)·2H_(2)O crystals of needle-like morphology.The mean gray intensity of the voids has a positive linear relationship with the threshold value,while the CT variance and void ratio have concave and convex relationships,respectively.The constitutive model can effectively match the stress–strain curves obtained from uniaxial compression experiments.This study provides comprehensive explanations of the failure modes and anisotropic mechanisms of 3DP gypsum samples,which is important for characterizing and understanding the failure mechanism and microstructural evolution of 3DP rocks when modeling natural rock behavior.展开更多
3-Nitro-1,2,4-triazol-5-one(NTO)is a typical high-energy,low-sensitivity explosive,and accurate concentration monitoring is critical for crystallization process control.In this study,a high-precision quantitative anal...3-Nitro-1,2,4-triazol-5-one(NTO)is a typical high-energy,low-sensitivity explosive,and accurate concentration monitoring is critical for crystallization process control.In this study,a high-precision quantitative analytical model for NTO concentration in ethanol solutions was developed by integrating real-time ATR-FTIR spectroscopy with chemometric and machine learning techniques.Dynamic spectral data were obtained by designing multi-concentration gradient heating-cooling cycle experiments,abnormal samples were eliminated using the isolation forest algorithm,and the effects of various preprocessing methods on model performance were systematically evaluated.The results show that partial least squares regression(PLSR)exhibits superior generalization ability compared to other models.Vibrational bands corresponding to C=O and–NO_(2)were identified as key predictors for concentration estimation.This work provides an efficient and reliable solution for real-time concentration monitoring during NTO crystallization and holds significant potential for process analytical applications in energetic material manufacturing.展开更多
Laser-induced breakdown spectroscopy(LIBS)has become a widely used atomic spectroscopic technique for rapid coal analysis.However,the vast amount of spectral information in LIBS contains signal uncertainty,which can a...Laser-induced breakdown spectroscopy(LIBS)has become a widely used atomic spectroscopic technique for rapid coal analysis.However,the vast amount of spectral information in LIBS contains signal uncertainty,which can affect its quantification performance.In this work,we propose a hybrid variable selection method to improve the performance of LIBS quantification.Important variables are first identified using Pearson's correlation coefficient,mutual information,least absolute shrinkage and selection operator(LASSO)and random forest,and then filtered and combined with empirical variables related to fingerprint elements of coal ash content.Subsequently,these variables are fed into a partial least squares regression(PLSR).Additionally,in some models,certain variables unrelated to ash content are removed manually to study the impact of variable deselection on model performance.The proposed hybrid strategy was tested on three LIBS datasets for quantitative analysis of coal ash content and compared with the corresponding data-driven baseline method.It is significantly better than the variable selection only method based on empirical knowledge and in most cases outperforms the baseline method.The results showed that on all three datasets the hybrid strategy for variable selection combining empirical knowledge and data-driven algorithms achieved the lowest root mean square error of prediction(RMSEP)values of 1.605,3.478 and 1.647,respectively,which were significantly lower than those obtained from multiple linear regression using only 12 empirical variables,which are 1.959,3.718 and 2.181,respectively.The LASSO-PLSR model with empirical support and 20 selected variables exhibited a significantly improved performance after variable deselection,with RMSEP values dropping from 1.635,3.962 and 1.647 to 1.483,3.086 and 1.567,respectively.Such results demonstrate that using empirical knowledge as a support for datadriven variable selection can be a viable approach to improve the accuracy and reliability of LIBS quantification.展开更多
Liquid chromatography-electrospray ionization tandem mass spectrometry(LC-ESI-MS)is a widely utilized technique for in vivo pharmaceutical analysis.Ionization interference within electrospray ion source,occurring betw...Liquid chromatography-electrospray ionization tandem mass spectrometry(LC-ESI-MS)is a widely utilized technique for in vivo pharmaceutical analysis.Ionization interference within electrospray ion source,occurring between drugs and metabolites,can lead to signal variations,potentially compromising quantitative accuracy.Currently,method validation often overlooks this type of signal interference,which may result in systematic errors in quantitative results without matrix-matched calibration.In this study,we conducted an investigation using ten different groups of drugs and their corresponding metabolites across three LC-ESI-MS systems to assess the prevalence of signal interference.Such interferences can potentially cause or enhance nonlinearity in the calibration curves of drugs and metabolites,thereby altering the relationship between analyte response and concentration for quantification.Finally,we established an evaluation scheme through a step-by-step dilution assay and employed three resolution methods:chromatographic separation,dilution,and stable labeled isotope internal standards correction.The above strategies were integrated into the method establishment process to improve quantitative accuracy.展开更多
Copper-based azide(Cu(N_(3))2 or CuN_(3),CA)chips synthesized by in-situ azide reaction and utilized in miniaturized explosive systems has become a hot research topic in recent years.However,the advantages of in-situ ...Copper-based azide(Cu(N_(3))2 or CuN_(3),CA)chips synthesized by in-situ azide reaction and utilized in miniaturized explosive systems has become a hot research topic in recent years.However,the advantages of in-situ synthesis method,including small size and low dosage,bring about difficulties in quantitative analysis and differences in ignition capabilities of CA chips.The aim of present work is to develop a simplified quantitative analysis method for accurate and safe analysis of components in CA chips to evaluate and investigate the corresponding ignition ability.In this work,Cu(N_(3))2 and CuN_(3)components in CA chips were separated through dissolution and distillation by utilizing the difference in solubility and corresponding content was obtained by measuring N_(3)-concentration through spectrophotometry.The spectrophotometry method was optimized by studying influencing factors and the recovery rate of different separation methods was studied,ensuring the accuracy and reproducibility of test results.The optimized method is linear in range from 1.0-25.0 mg/L,with a correlation coefficient R^(2)=0.9998,which meets the requirements of CA chips with a milligram-level content test.Compared with the existing ICP method,component analysis results of CA chips obtained by spectrophotometry are closer to real component content in samples and have satisfactory accuracy.Moreover,as its application in miniaturized explosive systems,the ignition ability of CA chips with different component contents for direct ink writing CL-20 and the corresponding mechanism was studied.This study provided a basis and idea for the design and performance evaluation of CA chips in miniaturized explosive systems.展开更多
To obtain more stable spectral data for accurate quantitative analysis of multi-element,especially for the large-area in-situ elements detection of soils, we propose a method for a multielement quantitative analysis o...To obtain more stable spectral data for accurate quantitative analysis of multi-element,especially for the large-area in-situ elements detection of soils, we propose a method for a multielement quantitative analysis of soils using calibration-free laser-induced breakdown spectroscopy(CF-LIBS) based on data filtering. In this study, we analyze a standard soil sample doped with two heavy metal elements, Cu and Cd, with a specific focus on the line of Cu I324.75 nm for filtering the experimental data of multiple sample sets. Pre-and post-data filtering,the relative standard deviation for Cu decreased from 30% to 10%, The limits of detection(LOD)values for Cu and Cd decreased by 5% and 4%, respectively. Through CF-LIBS, a quantitative analysis was conducted to determine the relative content of elements in soils. Using Cu as a reference, the concentration of Cd was accurately calculated. The results show that post-data filtering, the average relative error of the Cd decreases from 11% to 5%, indicating the effectiveness of data filtering in improving the accuracy of quantitative analysis. Moreover, the content of Si, Fe and other elements can be accurately calculated using this method. To further correct the calculation, the results for Cd was used to provide a more precise calculation. This approach is of great importance for the large-area in-situ heavy metals and trace elements detection in soil, as well as for rapid and accurate quantitative analysis.展开更多
The stable sub-angstrom resolution of the aberration-corrected scanning transmission electron microscope(ACSTEM)makes it an advanced and practical characterization technique for all materials.Owing to the prosperous a...The stable sub-angstrom resolution of the aberration-corrected scanning transmission electron microscope(ACSTEM)makes it an advanced and practical characterization technique for all materials.Owing to the prosperous advancement in computational technology,specialized software and programs have emerged as potent facilitators across the entirety of electron microscopy characterization process.Utilizing advanced image processing algorithms promotes the rectification of image distortions,concurrently elevating the overall image quality to superior standards.Extracting high-resolution,pixel-level discrete information and converting it into atomic-scale,followed by performing statistical calculations on the physical matters of interest through quantitative analysis,represent an effective strategy to maximize the value of electron microscope images.The efficacious utilization of quantitative analysis of electron microscope images has become a progressively prominent consideration for materials scientists and electron microscopy researchers.This article offers a concise overview of the pivotal procedures in quantitative analysis and summarizes the computational methodologies involved from three perspectives:contrast,lattice and strain,as well as atomic displacements and polarization.It further elaborates on practical applications of these methods in electronic functional materials,notably in piezoelectrics/ferroelectrics and thermoelectrics.It emphasizes the indispensable role of quantitative analysis in fundamental theoretical research,elucidating the structure–property correlations in high-performance systems,and guiding synthesis strategies.展开更多
Rapid and sensitive detection of dissolved gases in seawater is quite essential for the investigation of the global carbon cycle.Large quantities of in situ optical detection techniques showed restricted measurement e...Rapid and sensitive detection of dissolved gases in seawater is quite essential for the investigation of the global carbon cycle.Large quantities of in situ optical detection techniques showed restricted measurement efficiency,owing to the single gas sensor without the identification ability of multiple gases.In this work,a novel gas-liquid Raman detection method of monitoring the multi-component dissolved gases was proposed based on a continuous gas-liquid separator under a large difference of partial pressure.The limit of detection(LOD)of the gas Raman spectrometer could arrive at about 14 μl·L^(-1)for N_(2)gas.Moreover,based on the continuous gas-liquid separation process,the detection time of the dissolved gases could be largely decreased to about 200 s compared with that of the traditional detection method(30 min).Effect of equilibrium time on gas-liquid separation process indicated that the extracted efficiency and decay time of these dissolved gases was CO_(2)>O_(2)>N_(2).In addition,the analysis of the relationship between equilibrium time and flow speed indicated that the decay time decreased with the increase of the flow speed.The validation and application of the developed system presented its great potential for studying the components and spatiotemporal distribution of dissolved gases in seawater.展开更多
This study proposes a batch rapid quantitative analysis method for multiple elements by combining the advantages of standard curve(SC)and calibration-free laser-induced breakdown spectroscopy(CF-LIBS)technology to ach...This study proposes a batch rapid quantitative analysis method for multiple elements by combining the advantages of standard curve(SC)and calibration-free laser-induced breakdown spectroscopy(CF-LIBS)technology to achieve synchronous,rapid,and accurate measurement of elements in a large number of samples,namely,SC-assisted CF-LIBS.Al alloy standard samples,divided into calibration and test samples,were applied to validate the proposed method.SC was built based on the characteristic line of Pb and Cr in the calibration sample,and the contents of Pb and Cr in the test sample were calculated with relative errors of 6%and 4%,respectively.SC built using Cr with multiple characteristic lines yielded better calculation results.The relative contents of ten elements in the test sample were calculated using CF-LIBS.Subsequently,the SC-assisted CF-LIBS was executed,with the majority of the calculation relative errors falling within the range of 2%-5%.Finally,the Al and Na contents of the Al alloy were predicted.The results demonstrate that it effectively enables the rapid and accurate quantitative analysis of multiple elements after a single-element SC analysis of the tested samples.Furthermore,this quantitative analysis method was successfully applied to soil and Astragalus samples,realizing an accurate calculation of the contents of multiple elements.Thus,it is important to advance the LIBS quantitative analysis and its related applications.展开更多
This paper presents a quantitative risk analysis of liquefied petroleum gas(LPG)transportation.An accident that happened on June 13,2020,on the highway near Wenling,China is studied as a case.In this accident,LPG carr...This paper presents a quantitative risk analysis of liquefied petroleum gas(LPG)transportation.An accident that happened on June 13,2020,on the highway near Wenling,China is studied as a case.In this accident,LPG carried by a tank truck on the highway leaked and caused a large explosion,which led to 20 deaths.Different methods are combined to calculate the consequence of the accident.Multi-energy model and rupture of vessel model are employed to calculate the overpressure;the simulation result of the multi-energy model is closer to the damage caused by the accident.The safety distances in accidents of LPG transport storage tanks of different capacities are calculated in this study;the results show that the damage of explosion will increase with the filling degree of the tank.Even though the filling degree is 90%(value required by law),the 99%fatality rate range will reach 42 m,which is higher than regulated distance between road and building.The social risk of the tank truck has also been calculated and the results show that the risk is not acceptable.The calculating method used in this study could evaluate the risk of LPG tanker more accurately,which may contribute to the establishment of transportation regulation so that losses from similar accidents in the future could be reduced.展开更多
This paper extends the quantitative stability results to a more general class of two-stage stochastic variational inequality problems(TSVIP).The existence of solutions to the TSVIP is discussed,and the quantitative re...This paper extends the quantitative stability results to a more general class of two-stage stochastic variational inequality problems(TSVIP).The existence of solutions to the TSVIP is discussed,and the quantitative relationship between the TSVIP and its distribution perturbed problem is derived.展开更多
The broad-crested weir is convenient to construct and has a small amount of ex-cavation,widely used in practical engineering.Discharge computing has been the focus of research on this structure,thus developing general...The broad-crested weir is convenient to construct and has a small amount of ex-cavation,widely used in practical engineering.Discharge computing has been the focus of research on this structure,thus developing generalized regression neural network(GRNN),genetic programming(GP),and extreme learning machine(ELM)are used to predict the discharge coefficient(Cd)of the triangular broad-crested weir.The comprehensive analysis shows that the ELM model has high stability,predictive ability,and computational speed.The coefficient of determination(R^2)is 0.99982,the mean absolute percentage error(MAPE)is 0.000261,the Nash-Sutcliffe coefficient(NSE)is 0.99977,and the root means square error(RMSE)is 4.17E-05 in the testing phase.The apex angleθis the most critical parameter affecting the Cd,and the contribution to the Cd is 52.45%.A new computational formula is proposed and compared with the accuracy of empirical formulas,showing that the intelligent method has higher accuracy and efficiency.展开更多
Huang-Lian-Jie-Du-Decoction (HLJDD) has been widely used for the treatment of Alzheimer's disease (AD) in clinic. However, the relationship between its chemical profile and neuroprotective bioactivity was not cle...Huang-Lian-Jie-Du-Decoction (HLJDD) has been widely used for the treatment of Alzheimer's disease (AD) in clinic. However, the relationship between its chemical profile and neuroprotective bioactivity was not clearly clarified yet. In present study, the water extract of HLJDD and subsequent three polarity fractions divided by different reagents were investigated. A total of 17 chromatographic peaks were confirmed by comparison with standards and their UV, MS spectra. Among them, 11 major compounds were determined by HPLC-DAD method with good linear regression relationship (r2, 0.9994-0.9999), precisions (inter-day precision RSD, 0.79%-1.07%; intra-day precision RSD, 1.59%-2.10%), repeatability (RSD, 1.66%-3.67%), stability (RSD, 1.26%-4.77%) and recovery (95.24%-105.41%, RSD, 0.29%-2.69%). Furthermore, PC12 cells and primary neurons cells were used for the neuroprotective effective assessment of aforementioned four samples from HLJDD. 3"he total aqueous extract and n-butanol extract of HLJDD presented more significant effects than the other two parts. According to their quality and quantity determination results, iridoids and alkaloids have a positive correlation with the neuroprotective effectiveness of HLJDD.展开更多
A reliable and accurate HPLC/UV method was developed for the quantitative determination of astragaloside IV in 'Huang-Qi-Si-Wu' Capsules, a widely used prescription of traditional Chinese medicines (TCM). The chro...A reliable and accurate HPLC/UV method was developed for the quantitative determination of astragaloside IV in 'Huang-Qi-Si-Wu' Capsules, a widely used prescription of traditional Chinese medicines (TCM). The chromatographic separation conditions employed for HPLC/UV were optimized using a Hypersil-ODS column (250 mm^4.6 mm, 5.0 pm) with isocratic elution. Acetonitrile-water (32:68, v/v) were used as the mobile phase pumped at a flow rate of 1.0 mL/min and a detection wavelength at 203 nm was used. The method was fully validated with respect to linearity, precision, accuracy, specificity and robustness. The validated method was applied successfully to the quantification of astragaloside IV in the extract of 'Huang-Qi- Si-Wu' Capsules from different production batches. The results indicate that the established HPLC/UV method is suitable for the quantitative analysis and quality control of 'Huang-Qi-Si-Wu' Capsules and other related botanical drugs.展开更多
All-vanadium flow batteries(VFBs)are one of the most promising large-scale energy storage technologies.Conducting an operando quantitative analysis of the polarizations in VFBs under different conditions is essential ...All-vanadium flow batteries(VFBs)are one of the most promising large-scale energy storage technologies.Conducting an operando quantitative analysis of the polarizations in VFBs under different conditions is essential for developing high power density batteries.Here,we employ an operando decoupling method to quantitatively analyze the polarizations in each electrochemical and chemical reaction of VFBs under different catalytic conditions.Results show that the reduction reaction of V^(3+)presents the largest activation polarization,while the reduction reaction of VO_(2)^(+)primarily contributes to concentration polarizations due to the formation of the intermediate product V_(2)O_(3)^(3+).Additionally,it is found that the widely used electrode catalytic methods,incorporating oxygen functional groups and electrodepositing Bi,not only enhance the reaction kinetics but also exacerbate concentration polarizations simultaneously,especially during the discharge process.Specifically,in the battery with the high oxygen-containing electrodes,the negative side still accounts for the majority of activation loss(75.3%)at 200 mA cm^(-2),but it comes down to 36,9% after catalyzing the negative reactions with bismuth.This work provides an effective way to probe the limiting steps in flow batteries under various working conditions and offers insights for effectively enhancing battery performance for future developments.展开更多
文摘Dear Editor,We read with a great interest the recently published systematic review by Shamsikhani and Hosseini titled,“Foot reflexology on nausea and vomiting:A systematic review.”[1]While the authors provided a comprehensive qualitative synthesis of six studies meeting their inclusion criteria,we believe that additional quantitative analysis would strengthen the evidence base for foot reflexology in managing nausea and vomiting.We conducted a complementary meta-analysis to provide quantitative evidence supporting the qualitative findings presented in the systematic review.
文摘Cryptocurrency,a booming decentralised asset designed based on the blockchain architecture,is particularly important to the market at the present time by studying the volatility risk of cryptocurrencies.In this paper,we empirically analyse the volatility risk of cryptocurrencies through quantitative analysis models,comprehensively using the Markov state transition GARCH model with skewed distribution(Skew-MSGARCH)and the autoregressive conditional volatility density ARJI model introducing the Poisson jump factor,and selecting the earliest developed and the most mature currency price volatility daily return series,to deeply explore the volatility risk of digital cryptocurrencies.risk.Finally,it can be seen through in-depth analyses that the expectation factor and information inducement are the main reasons leading to the exacerbation of the volatility risk of digital cryptocurrencies.It is recommended that this situation be optimised and improved in terms of the value function of digital cryptocurrencies themselves and the implementation of systematic risk management and regulatory innovation.As an important component of the digital economy,blockchain technology can effectively regulate and improve the volatility of digital cryptocurrencies under macroeconomic policies,thereby maintaining the security and stability of emerging financial markets.
文摘Objective To quantitatively analyze the policy of centralized drug procurement centralized drug procurement in order to provide reference for the subsequent policy formulation and improvement.Methods Text mining method was used to process 15 centralized drugs procurement policies issued at the national level during 2015-2022,and a PMC index evaluation model of centralized drug procurement policies was established.Then,15 centralized drug procurement policies were quantitatively analyzed from the overall and comparative perspective through an evaluation model.Results and Conclusion The average PMC index of 15 centralized drug procurement policies was 6.95,which was acceptable on the whole.Among them,eight were excellent and seven were acceptable.As to the first-order variables,the centralized drugs procurement policy still lacks incentives and constraints.The comparative results show that there are differences in the content and structure of policies,but they are strongly related to each other.Chinese centralized drug procurement policy has been basically formed,which is closely related to medical insurance and medical policies.However,it is still necessary to pay attention to the structure of the policy to ensure the elaboration of the policy content.
基金financially supported by National Natural Science Foundation of China (Nos.62305392 and 62305123)Independent Research and Development Project of Naval Engineering University (No.2023504050)the Nursery Plan Project of Navel University of Engineering (2022)。
文摘Optimization and simplification of optical systems represent a milestone in advancing the development of handheld and portable laser-induced breakdown spectroscopy(LIBS)systems towards smaller,more integrated forms.This research,for the first time,conducted a comprehensive optimization design and comparative analysis of three compact LIBS system optical paths:the paraxial optical path(OP),the off-axis OP,and the reflective OP.The differences in spectral intensity and stability among these paths were revealed,providing a scientific basis for selecting the optimal OP for LIBS systems.The research found that the paraxial OP excels in spectral performance and quantitative analysis accuracy,making it the preferred choice for compact LIBS systems.Specifically,the paraxial OP significantly enhances spectral intensity,achieving a 6 times improvement over the off-axis OP and an even more remarkable 150 times increase compared to the reflective OP,greatly enhancing detection sensitivity.Additionally,the relative standard deviation,spectral stability index,maintains a consistently low level,ranging from 10.9%to 13.4%,significantly outperforming the other two OPs and ensuring the reliability of analytical results.In the field of quantitative analysis,the paraxial OP also demonstrates higher accuracy,precision,and sensitivity,comparing to other OPs.The quantitative analysis models for Si,Cu,and Ti elements exhibit excellent fitting,providing users with high-quality quantitative analysis results that are of great significance for applications in material science,environmental monitoring,industrial inspection,and other fields.In summary,this study not only confirms the enormous application potential of the paraxial OP in compact LIBS systems but also provides valuable practical experience and theoretical support for the miniaturization and integration of LIBS systems.Looking ahead,with continuous technological advancements,the design of the paraxial OP is expected to further propel the widespread adoption of LIBS technology in portable,on-site detection applications.
基金supported by the National Natural Science Foundation of China(No.51975026)。
文摘Aero engines are key power components that provide thrust for the aircraft.The cerme turbine disc allows the new-generation domestic fighter aircraft to increase the overall thrust of the aero engine.Quantifying coatings and analyzing the stress on the teeth play critical roles in improving the turbine disc’s performance,which are two issues must be solved urgently.First,this work pro poses a quantitative analysis algorithm to conduct the Three-Dimensional(3D)distribution informa tion mining of the extracted coatings.Then,it proposes an Industrial Computed Laminography(ICL)reconstruction algorithm for non-destructively reconstructing the turbine disc’s high-quality3D morphological actual feature.Finally,a Finite Element Analysis(FEA)under the ultimate thrus is conducted on ICL reconstruction to verify the working status of the new-generation aero-engine turbine disc.The results show that the proposed quantitative analysis algorithm digitizes the aggre gated conditions of the coating with a statistically normalized Z_(1)value of–2.15 and a confidence leve higher than 95%.Three image-quality quantitative indicators:Peak Signal-to-Noise Ratio(PSNR)Structural Similarity Index Measure(SSIM),and Normalized Mean Square Distance(NMSD)of the proposed ICL reconstruction algorithm on turbine disc laminographic image are 26.45,0.88,and 0.73respectively,which are better than other algorithms.The mechanical analysis of ICL more realisti cally reflects the stress and deformation than that of 3D modeling.This work provides new ideas for the iterative research of new-generation aero-engine turbine discs.
基金supported by grants from the Human Resources Development program(Grant No.20204010600250)the Training Program of CCUS for the Green Growth(Grant No.20214000000500)by the Korea Institute of Energy Technology Evaluation and Planning(KETEP)funded by the Ministry of Trade,Industry,and Energy of the Korean Government(MOTIE).
文摘Three-dimensional printing(3DP)offers valuable insight into the characterization of natural rocks and the verification of theoretical models due to its high reproducibility and accurate replication of complex defects such as cracks and pores.In this study,3DP gypsum samples with different printing directions were subjected to a series of uniaxial compression tests with in situ micro-computed tomography(micro-CT)scanning to quantitatively investigate their mechanical anisotropic properties and damage evolution characteristics.Based on the two-dimensional(2D)CT images obtained at different scanning steps,a novel void ratio variable was derived using the mean value and variance of CT intensity.Additionally,a constitutive model was formulated incorporating the proposed damage variable,utilizing the void ratio variable.The crack evolution and crack morphology of 3DP gypsum samples were obtained and analyzed using the 3D models reconstructed from the CT images.The results indicate that 3DP gypsum samples exhibit mechanical anisotropic characteristics similar to those found in naturally sedimentary rocks.The mechanical anisotropy is attributed to the bedding planes formed between adjacent layers and pillar-like structures along the printing direction formed by CaSO_(4)·2H_(2)O crystals of needle-like morphology.The mean gray intensity of the voids has a positive linear relationship with the threshold value,while the CT variance and void ratio have concave and convex relationships,respectively.The constitutive model can effectively match the stress–strain curves obtained from uniaxial compression experiments.This study provides comprehensive explanations of the failure modes and anisotropic mechanisms of 3DP gypsum samples,which is important for characterizing and understanding the failure mechanism and microstructural evolution of 3DP rocks when modeling natural rock behavior.
基金supported by the Aeronautical Science Foundation of China(Grant No.20230018072011)。
文摘3-Nitro-1,2,4-triazol-5-one(NTO)is a typical high-energy,low-sensitivity explosive,and accurate concentration monitoring is critical for crystallization process control.In this study,a high-precision quantitative analytical model for NTO concentration in ethanol solutions was developed by integrating real-time ATR-FTIR spectroscopy with chemometric and machine learning techniques.Dynamic spectral data were obtained by designing multi-concentration gradient heating-cooling cycle experiments,abnormal samples were eliminated using the isolation forest algorithm,and the effects of various preprocessing methods on model performance were systematically evaluated.The results show that partial least squares regression(PLSR)exhibits superior generalization ability compared to other models.Vibrational bands corresponding to C=O and–NO_(2)were identified as key predictors for concentration estimation.This work provides an efficient and reliable solution for real-time concentration monitoring during NTO crystallization and holds significant potential for process analytical applications in energetic material manufacturing.
基金financial supports from National Natural Science Foundation of China(No.62205172)Huaneng Group Science and Technology Research Project(No.HNKJ22-H105)Tsinghua University Initiative Scientific Research Program and the International Joint Mission on Climate Change and Carbon Neutrality。
文摘Laser-induced breakdown spectroscopy(LIBS)has become a widely used atomic spectroscopic technique for rapid coal analysis.However,the vast amount of spectral information in LIBS contains signal uncertainty,which can affect its quantification performance.In this work,we propose a hybrid variable selection method to improve the performance of LIBS quantification.Important variables are first identified using Pearson's correlation coefficient,mutual information,least absolute shrinkage and selection operator(LASSO)and random forest,and then filtered and combined with empirical variables related to fingerprint elements of coal ash content.Subsequently,these variables are fed into a partial least squares regression(PLSR).Additionally,in some models,certain variables unrelated to ash content are removed manually to study the impact of variable deselection on model performance.The proposed hybrid strategy was tested on three LIBS datasets for quantitative analysis of coal ash content and compared with the corresponding data-driven baseline method.It is significantly better than the variable selection only method based on empirical knowledge and in most cases outperforms the baseline method.The results showed that on all three datasets the hybrid strategy for variable selection combining empirical knowledge and data-driven algorithms achieved the lowest root mean square error of prediction(RMSEP)values of 1.605,3.478 and 1.647,respectively,which were significantly lower than those obtained from multiple linear regression using only 12 empirical variables,which are 1.959,3.718 and 2.181,respectively.The LASSO-PLSR model with empirical support and 20 selected variables exhibited a significantly improved performance after variable deselection,with RMSEP values dropping from 1.635,3.962 and 1.647 to 1.483,3.086 and 1.567,respectively.Such results demonstrate that using empirical knowledge as a support for datadriven variable selection can be a viable approach to improve the accuracy and reliability of LIBS quantification.
基金support provided by the National Natural Science Foundation of China(Grant No.:82173776)Natural Science Foundation of Guangdong Province,China(Grant No.:2021A1515010574)Guangdong Basic and Applied Basic Research Foundation,China(Grant No.:2021A1515110346).
文摘Liquid chromatography-electrospray ionization tandem mass spectrometry(LC-ESI-MS)is a widely utilized technique for in vivo pharmaceutical analysis.Ionization interference within electrospray ion source,occurring between drugs and metabolites,can lead to signal variations,potentially compromising quantitative accuracy.Currently,method validation often overlooks this type of signal interference,which may result in systematic errors in quantitative results without matrix-matched calibration.In this study,we conducted an investigation using ten different groups of drugs and their corresponding metabolites across three LC-ESI-MS systems to assess the prevalence of signal interference.Such interferences can potentially cause or enhance nonlinearity in the calibration curves of drugs and metabolites,thereby altering the relationship between analyte response and concentration for quantification.Finally,we established an evaluation scheme through a step-by-step dilution assay and employed three resolution methods:chromatographic separation,dilution,and stable labeled isotope internal standards correction.The above strategies were integrated into the method establishment process to improve quantitative accuracy.
基金the financial support provided by the National Natural Science Foundation of China(Grant No.11872013).
文摘Copper-based azide(Cu(N_(3))2 or CuN_(3),CA)chips synthesized by in-situ azide reaction and utilized in miniaturized explosive systems has become a hot research topic in recent years.However,the advantages of in-situ synthesis method,including small size and low dosage,bring about difficulties in quantitative analysis and differences in ignition capabilities of CA chips.The aim of present work is to develop a simplified quantitative analysis method for accurate and safe analysis of components in CA chips to evaluate and investigate the corresponding ignition ability.In this work,Cu(N_(3))2 and CuN_(3)components in CA chips were separated through dissolution and distillation by utilizing the difference in solubility and corresponding content was obtained by measuring N_(3)-concentration through spectrophotometry.The spectrophotometry method was optimized by studying influencing factors and the recovery rate of different separation methods was studied,ensuring the accuracy and reproducibility of test results.The optimized method is linear in range from 1.0-25.0 mg/L,with a correlation coefficient R^(2)=0.9998,which meets the requirements of CA chips with a milligram-level content test.Compared with the existing ICP method,component analysis results of CA chips obtained by spectrophotometry are closer to real component content in samples and have satisfactory accuracy.Moreover,as its application in miniaturized explosive systems,the ignition ability of CA chips with different component contents for direct ink writing CL-20 and the corresponding mechanism was studied.This study provided a basis and idea for the design and performance evaluation of CA chips in miniaturized explosive systems.
基金supported by the Major Science and Technology Project of Gansu Province(No.22ZD6FA021-5)the Industrial Support Project of Gansu Province(Nos.2023CYZC-19 and 2021CYZC-22)the Science and Technology Project of Gansu Province(Nos.23YFFA0074,22JR5RA137 and 22JR5RA151).
文摘To obtain more stable spectral data for accurate quantitative analysis of multi-element,especially for the large-area in-situ elements detection of soils, we propose a method for a multielement quantitative analysis of soils using calibration-free laser-induced breakdown spectroscopy(CF-LIBS) based on data filtering. In this study, we analyze a standard soil sample doped with two heavy metal elements, Cu and Cd, with a specific focus on the line of Cu I324.75 nm for filtering the experimental data of multiple sample sets. Pre-and post-data filtering,the relative standard deviation for Cu decreased from 30% to 10%, The limits of detection(LOD)values for Cu and Cd decreased by 5% and 4%, respectively. Through CF-LIBS, a quantitative analysis was conducted to determine the relative content of elements in soils. Using Cu as a reference, the concentration of Cd was accurately calculated. The results show that post-data filtering, the average relative error of the Cd decreases from 11% to 5%, indicating the effectiveness of data filtering in improving the accuracy of quantitative analysis. Moreover, the content of Si, Fe and other elements can be accurately calculated using this method. To further correct the calculation, the results for Cd was used to provide a more precise calculation. This approach is of great importance for the large-area in-situ heavy metals and trace elements detection in soil, as well as for rapid and accurate quantitative analysis.
基金Project supported by the financial support from the National Key R&D Program of China(Grant No.2021YFB3201100)the National Natural Science Foundation of China(Grant No.52172128)the Top Young Talents Programme of Xi’an Jiaotong University.
文摘The stable sub-angstrom resolution of the aberration-corrected scanning transmission electron microscope(ACSTEM)makes it an advanced and practical characterization technique for all materials.Owing to the prosperous advancement in computational technology,specialized software and programs have emerged as potent facilitators across the entirety of electron microscopy characterization process.Utilizing advanced image processing algorithms promotes the rectification of image distortions,concurrently elevating the overall image quality to superior standards.Extracting high-resolution,pixel-level discrete information and converting it into atomic-scale,followed by performing statistical calculations on the physical matters of interest through quantitative analysis,represent an effective strategy to maximize the value of electron microscope images.The efficacious utilization of quantitative analysis of electron microscope images has become a progressively prominent consideration for materials scientists and electron microscopy researchers.This article offers a concise overview of the pivotal procedures in quantitative analysis and summarizes the computational methodologies involved from three perspectives:contrast,lattice and strain,as well as atomic displacements and polarization.It further elaborates on practical applications of these methods in electronic functional materials,notably in piezoelectrics/ferroelectrics and thermoelectrics.It emphasizes the indispensable role of quantitative analysis in fundamental theoretical research,elucidating the structure–property correlations in high-performance systems,and guiding synthesis strategies.
基金the National Natural Science Foundation of China(52304236)the Natural Science Foundation of Shandong Province(ZR2021QE076)for the financial support to this research extracted from the project.
文摘Rapid and sensitive detection of dissolved gases in seawater is quite essential for the investigation of the global carbon cycle.Large quantities of in situ optical detection techniques showed restricted measurement efficiency,owing to the single gas sensor without the identification ability of multiple gases.In this work,a novel gas-liquid Raman detection method of monitoring the multi-component dissolved gases was proposed based on a continuous gas-liquid separator under a large difference of partial pressure.The limit of detection(LOD)of the gas Raman spectrometer could arrive at about 14 μl·L^(-1)for N_(2)gas.Moreover,based on the continuous gas-liquid separation process,the detection time of the dissolved gases could be largely decreased to about 200 s compared with that of the traditional detection method(30 min).Effect of equilibrium time on gas-liquid separation process indicated that the extracted efficiency and decay time of these dissolved gases was CO_(2)>O_(2)>N_(2).In addition,the analysis of the relationship between equilibrium time and flow speed indicated that the decay time decreased with the increase of the flow speed.The validation and application of the developed system presented its great potential for studying the components and spatiotemporal distribution of dissolved gases in seawater.
基金supported by the Major Science and TechnologyTechnol-ogy Projects in Gansu Province(No.22ZD6FA021-5)Industrial Support Project of Gansu Province(Nos.2023CYZC-19 and 2021CYZC-22)+1 种基金Science and Technol-ogy Project of Gansu Province(Nos.23YFFA0074,22JR5RA137,and 22JR5RA151)Central Leading Local Science and Technology Development Fund Projects(No.23ZYQA293).
文摘This study proposes a batch rapid quantitative analysis method for multiple elements by combining the advantages of standard curve(SC)and calibration-free laser-induced breakdown spectroscopy(CF-LIBS)technology to achieve synchronous,rapid,and accurate measurement of elements in a large number of samples,namely,SC-assisted CF-LIBS.Al alloy standard samples,divided into calibration and test samples,were applied to validate the proposed method.SC was built based on the characteristic line of Pb and Cr in the calibration sample,and the contents of Pb and Cr in the test sample were calculated with relative errors of 6%and 4%,respectively.SC built using Cr with multiple characteristic lines yielded better calculation results.The relative contents of ten elements in the test sample were calculated using CF-LIBS.Subsequently,the SC-assisted CF-LIBS was executed,with the majority of the calculation relative errors falling within the range of 2%-5%.Finally,the Al and Na contents of the Al alloy were predicted.The results demonstrate that it effectively enables the rapid and accurate quantitative analysis of multiple elements after a single-element SC analysis of the tested samples.Furthermore,this quantitative analysis method was successfully applied to soil and Astragalus samples,realizing an accurate calculation of the contents of multiple elements.Thus,it is important to advance the LIBS quantitative analysis and its related applications.
基金the Research Project of National Engineering Research Center for Petroleum Refining Technology and Catalyst(RIPP,SINOPEC)the National Key Research and Development Program of China(No.2018YFC0808600)。
文摘This paper presents a quantitative risk analysis of liquefied petroleum gas(LPG)transportation.An accident that happened on June 13,2020,on the highway near Wenling,China is studied as a case.In this accident,LPG carried by a tank truck on the highway leaked and caused a large explosion,which led to 20 deaths.Different methods are combined to calculate the consequence of the accident.Multi-energy model and rupture of vessel model are employed to calculate the overpressure;the simulation result of the multi-energy model is closer to the damage caused by the accident.The safety distances in accidents of LPG transport storage tanks of different capacities are calculated in this study;the results show that the damage of explosion will increase with the filling degree of the tank.Even though the filling degree is 90%(value required by law),the 99%fatality rate range will reach 42 m,which is higher than regulated distance between road and building.The social risk of the tank truck has also been calculated and the results show that the risk is not acceptable.The calculating method used in this study could evaluate the risk of LPG tanker more accurately,which may contribute to the establishment of transportation regulation so that losses from similar accidents in the future could be reduced.
基金Supported by the Guangxi Natural Science Foundation (2024GXNSFBA010345)the Innovation and Entrepreneurship Training Program of Guangxi Minzu University (S202310608001)。
文摘This paper extends the quantitative stability results to a more general class of two-stage stochastic variational inequality problems(TSVIP).The existence of solutions to the TSVIP is discussed,and the quantitative relationship between the TSVIP and its distribution perturbed problem is derived.
基金Xi'an University of Technology Excellent Master Seed Fund,Grant/Award Number:310/252082213。
文摘The broad-crested weir is convenient to construct and has a small amount of ex-cavation,widely used in practical engineering.Discharge computing has been the focus of research on this structure,thus developing generalized regression neural network(GRNN),genetic programming(GP),and extreme learning machine(ELM)are used to predict the discharge coefficient(Cd)of the triangular broad-crested weir.The comprehensive analysis shows that the ELM model has high stability,predictive ability,and computational speed.The coefficient of determination(R^2)is 0.99982,the mean absolute percentage error(MAPE)is 0.000261,the Nash-Sutcliffe coefficient(NSE)is 0.99977,and the root means square error(RMSE)is 4.17E-05 in the testing phase.The apex angleθis the most critical parameter affecting the Cd,and the contribution to the Cd is 52.45%.A new computational formula is proposed and compared with the accuracy of empirical formulas,showing that the intelligent method has higher accuracy and efficiency.
基金Key Projects in the National Science & Technology Pillar Program during the 11thFive-Year Plan Period (Grant No.2008BAI51B02)National Natural Science Fund Project of China (Grant No. 81202904)
文摘Huang-Lian-Jie-Du-Decoction (HLJDD) has been widely used for the treatment of Alzheimer's disease (AD) in clinic. However, the relationship between its chemical profile and neuroprotective bioactivity was not clearly clarified yet. In present study, the water extract of HLJDD and subsequent three polarity fractions divided by different reagents were investigated. A total of 17 chromatographic peaks were confirmed by comparison with standards and their UV, MS spectra. Among them, 11 major compounds were determined by HPLC-DAD method with good linear regression relationship (r2, 0.9994-0.9999), precisions (inter-day precision RSD, 0.79%-1.07%; intra-day precision RSD, 1.59%-2.10%), repeatability (RSD, 1.66%-3.67%), stability (RSD, 1.26%-4.77%) and recovery (95.24%-105.41%, RSD, 0.29%-2.69%). Furthermore, PC12 cells and primary neurons cells were used for the neuroprotective effective assessment of aforementioned four samples from HLJDD. 3"he total aqueous extract and n-butanol extract of HLJDD presented more significant effects than the other two parts. According to their quality and quantity determination results, iridoids and alkaloids have a positive correlation with the neuroprotective effectiveness of HLJDD.
基金Scientific and Technological Innovation Project Foundation of Shanxi,China(Grant No.20090321099)
文摘A reliable and accurate HPLC/UV method was developed for the quantitative determination of astragaloside IV in 'Huang-Qi-Si-Wu' Capsules, a widely used prescription of traditional Chinese medicines (TCM). The chromatographic separation conditions employed for HPLC/UV were optimized using a Hypersil-ODS column (250 mm^4.6 mm, 5.0 pm) with isocratic elution. Acetonitrile-water (32:68, v/v) were used as the mobile phase pumped at a flow rate of 1.0 mL/min and a detection wavelength at 203 nm was used. The method was fully validated with respect to linearity, precision, accuracy, specificity and robustness. The validated method was applied successfully to the quantification of astragaloside IV in the extract of 'Huang-Qi- Si-Wu' Capsules from different production batches. The results indicate that the established HPLC/UV method is suitable for the quantitative analysis and quality control of 'Huang-Qi-Si-Wu' Capsules and other related botanical drugs.
基金supported by the Guangdong Major Project of Basic and Applied Basic Research(2023B0303000002)the National Natural Science Foundation of China(No.52206089)+3 种基金the Guangdong Basic and Applied Basic Research Foundation(2024A1515010288,2023B1515120005)the Natural Science Foundation of Shenzhen(JCYJ20230807093315033)the Shenzhen Engineering Research Center,Southern University of Science and Technology(No.XMHT20230208003)high level of special funds(G03034K001)。
文摘All-vanadium flow batteries(VFBs)are one of the most promising large-scale energy storage technologies.Conducting an operando quantitative analysis of the polarizations in VFBs under different conditions is essential for developing high power density batteries.Here,we employ an operando decoupling method to quantitatively analyze the polarizations in each electrochemical and chemical reaction of VFBs under different catalytic conditions.Results show that the reduction reaction of V^(3+)presents the largest activation polarization,while the reduction reaction of VO_(2)^(+)primarily contributes to concentration polarizations due to the formation of the intermediate product V_(2)O_(3)^(3+).Additionally,it is found that the widely used electrode catalytic methods,incorporating oxygen functional groups and electrodepositing Bi,not only enhance the reaction kinetics but also exacerbate concentration polarizations simultaneously,especially during the discharge process.Specifically,in the battery with the high oxygen-containing electrodes,the negative side still accounts for the majority of activation loss(75.3%)at 200 mA cm^(-2),but it comes down to 36,9% after catalyzing the negative reactions with bismuth.This work provides an effective way to probe the limiting steps in flow batteries under various working conditions and offers insights for effectively enhancing battery performance for future developments.