The laboratory established an efficient reversed-phase ultra-high-performance liquid chromatographyquadrupole time-of-flight mass spectrometry(UPLC-Q-TOF-MS)qualitative method for screening more than 2000 kinds of ris...The laboratory established an efficient reversed-phase ultra-high-performance liquid chromatographyquadrupole time-of-flight mass spectrometry(UPLC-Q-TOF-MS)qualitative method for screening more than 2000 kinds of risk substances(including local anesthetics,LAs)in cosmetics,which has been successfully applied in the analysis of actual samples.This work aims to develop a more convenient high performance liquid chromatography triple quadrupole mass spectrometry(HPLC-QQQ-MS/MS)method for the quantitative determination of LAs.Samples were ultrasonically extracted with methanol,separated on an Agilent Poroshell 120 EC-C18 column(2.1 mm×100 mm,2.7μm),and eluted with a gradient mobile phase consisting of 0.1%formic acid aqueous solution and methanol.Quantification was performed using the external standard method.The results show that all 23 LAs are effectively separated within 12 minutes,with good linearity in the corresponding concentration ranges and the correlation coefficients all greater than 0.99.The limits of detection(LOD)range from 0.0025 to 0.05μg/g,and the limits of quantification(LOQ)range from 0.01 to 0.1μg/g.The average recoveries of the 23 LAs in 5 blank cosmetic matrices are 80.68%-117.57%,with the relative standard deviations(RSDs)less than 5.98%.This method has good precision and high accuracy,and is suitable for the determination of LAs in 5 cosmetic matrices.展开更多
BEIJING,Feb.25(Xinhua)-In a territory more than twice the size of the European Union and where per capita GDP varies up to fourfold across provincia level regions,the challenge of modernizing China with the right solu...BEIJING,Feb.25(Xinhua)-In a territory more than twice the size of the European Union and where per capita GDP varies up to fourfold across provincia level regions,the challenge of modernizing China with the right solutions for diverse localities has become a test of governance wisdom.展开更多
This paper provides a systematic review of the histochemical localization,content characteristics,and influencing factors of saponins in Pseudostellaria heterophylla based on an extensive literature survey.It provides...This paper provides a systematic review of the histochemical localization,content characteristics,and influencing factors of saponins in Pseudostellaria heterophylla based on an extensive literature survey.It provides an in-depth analysis and summary of the effects of biological factors,environmental conditions,agronomic practices,processing methods,and continuous cropping obstacles on the synthesis of P.heterophylla saponins,as well as their underlying mechanisms.Based on identified gaps in the current literature,future research directions and prospects are proposed.The findings of this review offer valuable insights for advancing the understanding of the saponin biosynthesis mechanisms in P.heterophylla and for enhancing its quality.展开更多
In this paper,a theoretical model is established for locally resonant plates with general resonators,and the corresponding governing equation is derived.The model provides a mathematical demonstration of the locally r...In this paper,a theoretical model is established for locally resonant plates with general resonators,and the corresponding governing equation is derived.The model provides a mathematical demonstration of the locally resonant effect,which contains two parts:the first part is induced by translation coupling,and the second part is induced by rotation coupling.The second part cannot be reflected by most existing theoretical models.The analytical solutions of the dynamic response are compared with the direct numerical simulation(DNS)results for two locally resonant plates with different resonator types,thereby validating the general applicability of the present model.The rotation coupling effect leads to the frequency-dependent effective rotational inertia density and anisotropic dispersion relation of the locally resonant plate,as well as the enhancement of the structural vibration suppression ability.展开更多
The multi-pass intermittent local loading process,which features a more flexible processing path,can further enhance the second material distribution during local loading,improve the formability of components,and redu...The multi-pass intermittent local loading process,which features a more flexible processing path,can further enhance the second material distribution during local loading,improve the formability of components,and reduce forming loads.However,the absence of compatible forming equipment makes it difficult to control the constraint in the unloaded zones during the forming process.This difficulty complicates coordination and control of deformation,particularly for asymmetric rib-web components.Additionally,the current implementation involves multi-fire heating,a long process flow,and high energy consumption,which limits the popularization and application of the local loading process.In this study,a new multi-pass local loading hydraulic forming apparatus that can quickly and reliably switch between heavy-load deformation and low-load constraint for different local loading sub-dies was developed.A 10-tonne laboratory prototype was developed,and the forming characteristics during the forming process as well as the response characteristics of the hydraulic system during the multi-pass intermittent local loading of rib-web component were investigated using numerical simulations and physical experiments.Results indicated that,compared to a whole loading process with the same initial geometry of billet,the total forming load(i.e.,the sum of loaded and restrained loads)is reduced by more than 40%with the local loading process,and by nearly 50%with multi-pass local loading.The multi-pass local loading process allows for more effective control of material flow compared to single-pass local loading,leading to improved cavity filling and reduced flow line disturbance.For a large-scale,complex titanium alloy bulkhead,the cavity filling problem was addressed by optimizing the multi-pass local loading path with an unequal thickness billet.The dynamic performance of the multi-pass local loading hydraulic system was found to be robust,with stable pressure transitions during motion and load switching for the sub-die(s).The dynamic characteristic of the hydraulic cylinder when switching from non-moving/unloaded state to a moving/loading state are consistent whether a load is present or not.However,the dynamic characteristics differ when switching from a moving/loading state to non-moving/unloaded state,showing opposite behavior.The developed hydraulic drive mechanism provides a way for implementation of multi-pass local loading without auxiliary operation and extra heating.The results of the study provide a foundation for the industrial production of large-scale,complex components with reduced force requirement and low-energy consumption.展开更多
This paper investigates the following mixed local and nonlocal elliptic problem fea-turing concave-convex nonlinearities and a discontinuous right-hand side:{L(u)=H(u−μ)|u|^(p−2)u+λ|u|^(q−2)u,x∈Ω,u≥0,x∈Ω,u=0,x...This paper investigates the following mixed local and nonlocal elliptic problem fea-turing concave-convex nonlinearities and a discontinuous right-hand side:{L(u)=H(u−μ)|u|^(p−2)u+λ|u|^(q−2)u,x∈Ω,u≥0,x∈Ω,u=0,x∈R^(N)\Ω,where Ω ⊂R^(N)(N>2)is a bounded domain,μ≥0 and λ>0 are real parameters,H denotes the Heaviside function(H(t)=0 for t<0,H(t)=1 for t>0),and the mixed local and nolocal operator is defined as L(u)=−Δu+(−Δ)^(s)u with(−Δ)^(s) being the restricted fractional Laplace(0<s<1).The exponents satisfy 1<q<2<p.By employing a novel non-smooth variational principle,we establish the existence of an M-solution for this problem and identify a range for the exponent p.展开更多
Reconfigurable intelligent surfaces(RISs)not only assist communication but also help the localization of user equipment(UE).This study focuses on indoor localization of UE with a single access point(AP)and multiple RI...Reconfigurable intelligent surfaces(RISs)not only assist communication but also help the localization of user equipment(UE).This study focuses on indoor localization of UE with a single access point(AP)and multiple RISs.First,we propose a two-stage channel estimation scheme where RIS phase shifts are tuned to obtain multiple channel soundings.In the first stage,the newtonized orthogonal matching pursuit algorithm extracts the parameters of multiple paths from the received signals.Then,the LOS path and RISreflected paths are identified.In the second stage,the estimated path gains of RIS-reflected paths with different phase shifts are utilized to determine the angle of arrival(AOA)at the RIS by obtaining the angular pseudo spectrum.Consequently,by taking the AP and RISs as reference points,the linear least squares estimator can locate UE with the estimated AOAs.Simulation results show that the proposed algorithm can realize centimeter-level localization accuracy in the discussed scenarios.Moreover,the higher accuracy of pseudo spectrum,a larger number of channel soundings,and a larger number of reference points can realize higher localization accuracy of UE.展开更多
Background:The long-term outcomes of robotic-assisted surgery and the prognostic significance of the pretreatment neutrophil-to-lymphocyte ratio(NLR)in locally advanced rectal cancer(LARC)remain uncertain.This study a...Background:The long-term outcomes of robotic-assisted surgery and the prognostic significance of the pretreatment neutrophil-to-lymphocyte ratio(NLR)in locally advanced rectal cancer(LARC)remain uncertain.This study aimed to assess the long-term outcomes of patients with LARC undergoing robotic-assisted surgery and to determine the prognostic value of pretreatment NLR.Methods:We retrospectively reviewed 252 patients with LARC who were treated at a single medical center in Taiwan between January 2012 and January 2023.All patients underwent neoadjuvant concurrent chemoradiotherapy(CRT)followed by robotic-assisted surgery with total mesorectal excision(TME).Patients were stratified into four groups on the basis of pretreatment NLRs and carcinoembryonic antigen(CEA)levels.Univariate and multivariate analyses were conducted to identify prognostic indicators for overall survival(OS)and disease-free survival(DFS).Results:Patients with a pretreatment NLR of≥3.2 exhibited significantly worse OS and DFS compared with those with an NLR of<3.2(OS:94.4 vs.116.5 months,p=0.001;DFS:78.8 vs.101.7 months,p=0.003).Group A exhibited the poorest prognosis,whereas Group D had the most favorable outcomes.Multivariate analysis revealed NLR≥3.2 as an independent predictor of poor OS(hazard ratio[HR]=2.306,95%CI:1.149-3.747;p=0.001)and DFS(HR=2.055,95%CI:1.341-3.148;p=0.001).Conclusion:Neoadjuvant concurrent CRT followed by robotic-assisted TME is an effective treatment strategy for LARC.A higher pretreatment NLR(≥3.2)independently predicted worse OS and DFS.Stratification using the NLR in combination with CEA levels may enhance prognostic accuracy for patients undergoing robotic-assisted surgery for LARC.展开更多
The promotion of rural revitalization within the ecological conservation areas(“ECAs”) requires a careful balance between ecological protection and economic development and should be guided by the principle of ecolo...The promotion of rural revitalization within the ecological conservation areas(“ECAs”) requires a careful balance between ecological protection and economic development and should be guided by the principle of ecological priority. The cultivation of rural “Local Specialty Products”(“LSPs”) under a green-development framework aligns with the functional positioning of these areas, drives the revitalization of rural industries, and constitutes a fundamental strategy for addressing the unique challenges they face. Although ECAs possess inherent advantages in terms of developing LSPs, they are also confronted by multiple constraints. Accordingly, we propose development objectives that emphasize(a) driving rural industrial prosperity,(b) enhancing the appeal of agricultural heritage, and(c) ensuring inclusive prosperity in the farming communities. In selecting pathways for growth, priority should be given to improving the quality of products, fostering distinctiveness of the technologies, nurturing cultural identities, and upholding the principle of common prosperity. From a policy standpoint, the development of rural LSPs should be recognized as a key lever for advancing the comprehensiveness of rural revitalization in the ECAs. We recommend a set of supportive measures—namely, reinforcing the guidance for spatial planning, integrating the consolidation of factor inputs, and ensuring the robustness of organizational guarantees—to facilitate the high-quality development of LSPs in these areas.展开更多
In ultrasonic non-destructive testing of high-temperature industrial equipment,sound velocity drift induced by non-uniform temperature fields can severely compromise defect localization accuracy.Conventional approache...In ultrasonic non-destructive testing of high-temperature industrial equipment,sound velocity drift induced by non-uniform temperature fields can severely compromise defect localization accuracy.Conventional approaches that rely on room-temperature sound velocities introduce systematic errors,potentially leading to misjudgment of safety-critical components.Two primary challenges hinder current methods:first,it is difficult to monitor real-time changes in sound velocity distribution within a thermal gradient;second,traditional uniform-temperature correction models fail to capture the nonlinear dependence of material properties on temperature and their effect on ultrasonic velocity fields.Here,we propose a defect localization correction method based on multiphysics coupling.A two-dimensional coupled heat transfer–wave propagation model is established in COMSOL,and a one-dimensional steady-state heat transfer condition is used to design a numerical pulse–echo experiment in 1020 steel.Temperature-dependent material properties are incorporated,and the intrinsic relationship between sound velocity and temperature is derived,confirming consistency with classical theories.To account for gradient temperature fields,a micro-element integration algorithm discretizes the propagation path into segments,each associated with a locally computed temperature from the steady-state heat conduction solution.Defect positions are dynamically corrected through cumulative displacement along the propagation path.By integrating heat conduction and elastic wave propagation in a multiphysics framework,this method overcomes the limitations of uniform-temperature assumptions.The micro-element integration approach enables dynamic tracking of spatially varying sound velocities,offering a robust strategy to enhance ultrasonic testing accuracy in high-temperature industrial environments.展开更多
To investigate the damage evolution caused by stress-driven and sub-critical crack propagation within the Beishan granite under multi-creep triaxial compressive conditions,the distributed optical fiber sensing and X-r...To investigate the damage evolution caused by stress-driven and sub-critical crack propagation within the Beishan granite under multi-creep triaxial compressive conditions,the distributed optical fiber sensing and X-ray computed tomography were combined to obtain the strain distribution over the sample surface and internal fractures of the samples.The Gini and skewness(G-S)coefficients were used to quantify strain localization during tests,where the Gini coefficient reflects the degree of clustering of elements with high strain values,i.e.,strain localization/delocalization.The strain localization-induced asymmetry of data distribution is quantified by the skewness coefficient.A precursor to granite failure is defined by the rapid and simultaneous increase of the G-S coefficients,which are calculated from strain increment,giving an earlier warning of failure by about 8%peak stress than those from absolute strain values.Moreover,the process of damage accumulation due to stress-driven crack propagation in Beishan granite is different at various confining pressures as the stress exceeds the crack initiation stress.Concretely,strain localization is continuous until brittle failure at higher confining pressure,while both strain localization and delocalization occur at lower confining pressure.Despite the different stress conditions,a similar statistical characteristic of strain localization during the creep stage is observed.The Gini coefficient increases,and the skewness coefficient decreases slightly as the creep stress is below 95%peak stress.When the accelerated strain localization begins,the Gini and skewness coefficients increase rapidly and simultaneously.展开更多
The practical application of lithium metal batteries(LMBs)requires electrolytes that simultaneously ensure high safety and interfacial stability.Although locally concentrated ionic liquid electrolytes(LCILEs)exhibit e...The practical application of lithium metal batteries(LMBs)requires electrolytes that simultaneously ensure high safety and interfacial stability.Although locally concentrated ionic liquid electrolytes(LCILEs)exhibit exceptional electrochemical stability and compatibility with electrode electrolyte interfaces(EEIs),two major challenges persist:(i)safety risks caused by excessive low-flash-point diluents,and(ii)insufficient understanding of how diluents modulate solvation structures.Herein,we introduce a low-diluent-content LCILE system composed of lithium bis(fluorosulfonyl)imide(LiFSI)salt,N-methyl-N-propyl-pyrrolidinium bis(fluorosulfonyl)imide(Pyr_(13)FSI)ionic liquid,and trifluoromethanesulfonate(TFS)diluent.The TFS diluent strengthens ion-ion interactions by lowering the dielectric constant of the electrolyte,resulting in the formation of a unique nanometric anion aggregates(N-AGGs)reinforced solvation structure.These large anionic clusters exhibit accelerated redox decomposition kinetics,facilitating the rapid formation of a thin,dense,and low-impedance EEI.Consequently,the Li/LiNi_(0.6)Co_(0.2)Mn_(0.2)O_(2)coin cell achieves 87.8%capacity retention over 300 cycles at 4.3 V,while a practical 1.4 Ah Li/NCM622 pouch cell retains 84.5%capacity after 80 cycles at 4.5 V.Furthermore,the electrolyte demonstrates exceptional safety,and 2 Ah Li metal pouch cells successfully pass rigorous nail penetration tests without any ignition or explosion.This work not only provides a design strategy for intrinsically safe and high-performance electrolytes but also highlights the critical role of anion cluster decomposition kinetics in shaping EEI formation.展开更多
It is well known that the inhomogeneous Calderón-Zygmund convolution operators are bounded on the local Hardy spaces.In this paper,we prove that these operators are bounded on the local product Hardy spaces and t...It is well known that the inhomogeneous Calderón-Zygmund convolution operators are bounded on the local Hardy spaces.In this paper,we prove that these operators are bounded on the local product Hardy spaces and the Lipschitz spaces.The key ideas used here are the discrete local Calderón identity and a density argument for the inhomogeneous product Lipschitz spaces in the weak sense.展开更多
In this paper,we present local functional law of the iterated logarithm for Cs?rg?-Révész type increments of fractional Brownian motion.The results obtained extend works of Gantert[Ann.Probab.,1993,21(2):104...In this paper,we present local functional law of the iterated logarithm for Cs?rg?-Révész type increments of fractional Brownian motion.The results obtained extend works of Gantert[Ann.Probab.,1993,21(2):1045-1049]and Monrad and Rootzén[Probab.Theory Related Fields,1995,101(2):173-192].展开更多
Laser-welded Ti-6Al-4 V is prone to severe residual stresses,microstructural variation,and structural de-fects which are known detrimental to the mechanical properties of weld joints.Residual stress removal is typical...Laser-welded Ti-6Al-4 V is prone to severe residual stresses,microstructural variation,and structural de-fects which are known detrimental to the mechanical properties of weld joints.Residual stress removal is typically applied to weld joints for engineering purposes via heat treatment,in order to avoid prema-ture failure and performance degradation.In the present work,we found that proper welding residual stresses in laser-welded Ti-6Al-4 V sheets can maintain better ductility during uniaxial tension,as op-posed to the stress-relieved counterparts.A detailed experimental investigation has been performed on the deformation behaviours of Ti-6Al-4 V butt welds,including residual stress distribution characteriza-tions by focused ion beam ring-coring coupled with digital image correlation(FIB-DIC),X-ray comput-erized tomography(CT)for internal voids,and in-situ DIC analysis of the subregional strain evolutions.It was found that the pores preferentially distributed near the fusion zone(FZ)boundary,where the compressive residual stress was up to-330 MPa.The removal of residual stress resulted in a changed failure initiation site from the base material to the FZ boundary,the former with ductile and the latter with brittle fracture characteristics under tensile deformation.The combined effects of residual stresses,microstructures,and internal pores on the mechanical responses are discussed in detail.This work high-lights the importance of inevitable residual stress and pores in laser weld pieces,leading to key insights for post-welding treatment and service performance evaluations.展开更多
The proposed hybrid optimization algorithm integrates particle swarm optimizatio(PSO)with Ant Colony Optimization(ACO)to improve a number of pitfalls within PSO methods traditionally considered and/or applied to indus...The proposed hybrid optimization algorithm integrates particle swarm optimizatio(PSO)with Ant Colony Optimization(ACO)to improve a number of pitfalls within PSO methods traditionally considered and/or applied to industrial robots.Particle Swarm Optimization may frequently suffer from local optima and inaccuracies in identifying the geometric parameters,which are necessary for applications requiring high-accuracy performances.The proposed approach integrates pheromone-based learning of ACO with the D-H method of developing an error model;hence,the global search effectiveness together with the convergence accuracy is further improved.Comparison studies of the hybrid PSO-ACO algorithm show higher precision and effectiveness in the optimization of geometric error parameters compared to the traditional methods.This is a remarkable reduction of localization errors,thus yielding accuracy and reliability in industrial robotic systems,as the results show.This approach improves performance in those applications that demand high geometric calibration by reducing the geometric error.The paper provides an overview of input for developing robotics and automation,giving importance to precision in industrial engineering.The proposed hybrid methodology is a good way to enhance the working accuracy and effectiveness of industrial robots and shall enable their wide application to complex tasks that require a high degree of accuracy.展开更多
A multi-phase heterogeneous FeCoNi-based high-entropy alloy is developed to overcome the trade-off between strength and ductility.By alloying with a small amount of Cu and employing a rapid recrystalliza-tion process,...A multi-phase heterogeneous FeCoNi-based high-entropy alloy is developed to overcome the trade-off between strength and ductility.By alloying with a small amount of Cu and employing a rapid recrystalliza-tion process,it exhibits a good combination of yield strength(roughly 1300 MPa)and ductility(approach-ing 20%).Firstly,a multi-phase heterogeneous structure is tailored ranging from nano to micron.Cu is efficiently precipitated as nanoscale clusters(4.2 nm),high-density cuboidal L1_(2) particles(20-40 nm)and L2_(1) particles(500-800 nm)are found to be embedded in the matrix and a bimodal heterogeneous grain structure(1-40μm)is constructed.Secondly,the introduction of Cu effectively suppresses the pre-cipitation of coarse L21 phase at grain boundaries,reducing its volume fraction by 80%and replaced by smaller-scale continuous precipitations within the grains.Thirdly,the high mixing enthalpy gap of Cu and the matrix leads to the formation of local chemical fluctuation and the consequential rugged topog-raphy in the matrix,which result in retarded dislocation motion and promotes dislocation plugging and interlocking during strain,enhancing yield stress and work hardening rate.This study provides a valuable perspective to enhance strength and ductility via enlarged local chemical fluctuation-tailored multi-phase heterogeneous structures.展开更多
Spectrum-based fault localization (SBFL) generates a ranked list of suspicious elements by using the program execution spectrum, but the excessive number of elements ranked in parallel results in low localization accu...Spectrum-based fault localization (SBFL) generates a ranked list of suspicious elements by using the program execution spectrum, but the excessive number of elements ranked in parallel results in low localization accuracy. Most researchers consider intra-class dependencies to improve localization accuracy. However, some studies show that inter-class method call type faults account for more than 20%, which means such methods still have certain limitations. To solve the above problems, this paper proposes a two-phase software fault localization based on relational graph convolutional neural networks (Two-RGCNFL). Firstly, in Phase 1, the method call dependence graph (MCDG) of the program is constructed, the intra-class and inter-class dependencies in MCDG are extracted by using the relational graph convolutional neural network, and the classifier is used to identify the faulty methods. Then, the GraphSMOTE algorithm is improved to alleviate the impact of class imbalance on classification accuracy. Aiming at the problem of parallel ranking of element suspicious values in traditional SBFL technology, in Phase 2, Doc2Vec is used to learn static features, while spectrum information serves as dynamic features. A RankNet model based on siamese multi-layer perceptron is constructed to score and rank statements in the faulty method. This work conducts experiments on 5 real projects of Defects4J benchmark. Experimental results show that, compared with the traditional SBFL technique and two baseline methods, our approach improves the Top-1 accuracy by 262.86%, 29.59% and 53.01%, respectively, which verifies the effectiveness of Two-RGCNFL. Furthermore, this work verifies the importance of inter-class dependencies through ablation experiments.展开更多
Under the combination of currents and waves, seabed scour occurs around offshore wind turbine foundations, which affects the stability and safe operation of offshore wind turbines. In this study, physical model experi...Under the combination of currents and waves, seabed scour occurs around offshore wind turbine foundations, which affects the stability and safe operation of offshore wind turbines. In this study, physical model experiments under unidirectional flow, bidirectional flow, and wave-current interactions with different flow directions around the pile group foundation were first conducted to investigate the development of scour around the pile group foundation.Additionally, a three-dimensional scour numerical model was established via the open-source software REEF3D to simulate the flow field and scour around the prototype-scale foundation. The impact of flow on scour was discussed.Under unidirectional flow, scour equilibrium was reached more quickly, with the maximum scour depth reaching approximately 1.2 times the pile diameter and the extent of the scour hole spanning about 4.9 times the pile diameter.Compared with those under unidirectional flow, the scour depths under combinations of currents and waves, as well as bidirectional flow, were slightly smaller. However, the morphology of scour holes was more uniform and symmetrical. The numerical simulation results show good agreement with the experimental data, demonstrating the impact of varying flow directions on the velocity distribution around the foundation, the morphology of scour holes, and the location of the maximum scour depth.展开更多
文摘The laboratory established an efficient reversed-phase ultra-high-performance liquid chromatographyquadrupole time-of-flight mass spectrometry(UPLC-Q-TOF-MS)qualitative method for screening more than 2000 kinds of risk substances(including local anesthetics,LAs)in cosmetics,which has been successfully applied in the analysis of actual samples.This work aims to develop a more convenient high performance liquid chromatography triple quadrupole mass spectrometry(HPLC-QQQ-MS/MS)method for the quantitative determination of LAs.Samples were ultrasonically extracted with methanol,separated on an Agilent Poroshell 120 EC-C18 column(2.1 mm×100 mm,2.7μm),and eluted with a gradient mobile phase consisting of 0.1%formic acid aqueous solution and methanol.Quantification was performed using the external standard method.The results show that all 23 LAs are effectively separated within 12 minutes,with good linearity in the corresponding concentration ranges and the correlation coefficients all greater than 0.99.The limits of detection(LOD)range from 0.0025 to 0.05μg/g,and the limits of quantification(LOQ)range from 0.01 to 0.1μg/g.The average recoveries of the 23 LAs in 5 blank cosmetic matrices are 80.68%-117.57%,with the relative standard deviations(RSDs)less than 5.98%.This method has good precision and high accuracy,and is suitable for the determination of LAs in 5 cosmetic matrices.
文摘BEIJING,Feb.25(Xinhua)-In a territory more than twice the size of the European Union and where per capita GDP varies up to fourfold across provincia level regions,the challenge of modernizing China with the right solutions for diverse localities has become a test of governance wisdom.
基金Supported by Open Fund Project of the Engineering Technology Research Center of Characteristic Medicinal Plants of Fujian(PP202003).
文摘This paper provides a systematic review of the histochemical localization,content characteristics,and influencing factors of saponins in Pseudostellaria heterophylla based on an extensive literature survey.It provides an in-depth analysis and summary of the effects of biological factors,environmental conditions,agronomic practices,processing methods,and continuous cropping obstacles on the synthesis of P.heterophylla saponins,as well as their underlying mechanisms.Based on identified gaps in the current literature,future research directions and prospects are proposed.The findings of this review offer valuable insights for advancing the understanding of the saponin biosynthesis mechanisms in P.heterophylla and for enhancing its quality.
基金Project supported by the National Natural Science Foundation of China(No.12472062)。
文摘In this paper,a theoretical model is established for locally resonant plates with general resonators,and the corresponding governing equation is derived.The model provides a mathematical demonstration of the locally resonant effect,which contains two parts:the first part is induced by translation coupling,and the second part is induced by rotation coupling.The second part cannot be reflected by most existing theoretical models.The analytical solutions of the dynamic response are compared with the direct numerical simulation(DNS)results for two locally resonant plates with different resonator types,thereby validating the general applicability of the present model.The rotation coupling effect leads to the frequency-dependent effective rotational inertia density and anisotropic dispersion relation of the locally resonant plate,as well as the enhancement of the structural vibration suppression ability.
基金the supports of the National Natural Science Foundation of China(Grant No.52375378)。
文摘The multi-pass intermittent local loading process,which features a more flexible processing path,can further enhance the second material distribution during local loading,improve the formability of components,and reduce forming loads.However,the absence of compatible forming equipment makes it difficult to control the constraint in the unloaded zones during the forming process.This difficulty complicates coordination and control of deformation,particularly for asymmetric rib-web components.Additionally,the current implementation involves multi-fire heating,a long process flow,and high energy consumption,which limits the popularization and application of the local loading process.In this study,a new multi-pass local loading hydraulic forming apparatus that can quickly and reliably switch between heavy-load deformation and low-load constraint for different local loading sub-dies was developed.A 10-tonne laboratory prototype was developed,and the forming characteristics during the forming process as well as the response characteristics of the hydraulic system during the multi-pass intermittent local loading of rib-web component were investigated using numerical simulations and physical experiments.Results indicated that,compared to a whole loading process with the same initial geometry of billet,the total forming load(i.e.,the sum of loaded and restrained loads)is reduced by more than 40%with the local loading process,and by nearly 50%with multi-pass local loading.The multi-pass local loading process allows for more effective control of material flow compared to single-pass local loading,leading to improved cavity filling and reduced flow line disturbance.For a large-scale,complex titanium alloy bulkhead,the cavity filling problem was addressed by optimizing the multi-pass local loading path with an unequal thickness billet.The dynamic performance of the multi-pass local loading hydraulic system was found to be robust,with stable pressure transitions during motion and load switching for the sub-die(s).The dynamic characteristic of the hydraulic cylinder when switching from non-moving/unloaded state to a moving/loading state are consistent whether a load is present or not.However,the dynamic characteristics differ when switching from a moving/loading state to non-moving/unloaded state,showing opposite behavior.The developed hydraulic drive mechanism provides a way for implementation of multi-pass local loading without auxiliary operation and extra heating.The results of the study provide a foundation for the industrial production of large-scale,complex components with reduced force requirement and low-energy consumption.
基金Supported by the National Natural Science Foundation of China(Grant No.12361026)the Discipline Construction Fund Project of Northwest Minzu University.
文摘This paper investigates the following mixed local and nonlocal elliptic problem fea-turing concave-convex nonlinearities and a discontinuous right-hand side:{L(u)=H(u−μ)|u|^(p−2)u+λ|u|^(q−2)u,x∈Ω,u≥0,x∈Ω,u=0,x∈R^(N)\Ω,where Ω ⊂R^(N)(N>2)is a bounded domain,μ≥0 and λ>0 are real parameters,H denotes the Heaviside function(H(t)=0 for t<0,H(t)=1 for t>0),and the mixed local and nolocal operator is defined as L(u)=−Δu+(−Δ)^(s)u with(−Δ)^(s) being the restricted fractional Laplace(0<s<1).The exponents satisfy 1<q<2<p.By employing a novel non-smooth variational principle,we establish the existence of an M-solution for this problem and identify a range for the exponent p.
基金supported in part by the Fundamental Research Funds for the Central Universities under Grant 2242022k60004in part by the National Natural Science Foundation of China(NSFC)under Grants 62261160576,624B2036,W2421087,62422105+1 种基金in part by the Young Elite Scientists Sponsorship Program by CAST 2022QNRC001,and the“Zhishan”Scholars Programs of Southeast Universityin part by the Key Technologies R&D Program of Jiangsu(Prospective and Key Technologies for Industry)under Grants BE2023022,BE2023022-1 and BE2023022-2.
文摘Reconfigurable intelligent surfaces(RISs)not only assist communication but also help the localization of user equipment(UE).This study focuses on indoor localization of UE with a single access point(AP)and multiple RISs.First,we propose a two-stage channel estimation scheme where RIS phase shifts are tuned to obtain multiple channel soundings.In the first stage,the newtonized orthogonal matching pursuit algorithm extracts the parameters of multiple paths from the received signals.Then,the LOS path and RISreflected paths are identified.In the second stage,the estimated path gains of RIS-reflected paths with different phase shifts are utilized to determine the angle of arrival(AOA)at the RIS by obtaining the angular pseudo spectrum.Consequently,by taking the AP and RISs as reference points,the linear least squares estimator can locate UE with the estimated AOAs.Simulation results show that the proposed algorithm can realize centimeter-level localization accuracy in the discussed scenarios.Moreover,the higher accuracy of pseudo spectrum,a larger number of channel soundings,and a larger number of reference points can realize higher localization accuracy of UE.
基金supported by grants through funding from the National Science and Technology Council(NSTC112-2314-B-037-050-MY3,NSTC114-2314-B-037-103-MY3,NSTC114-2321-B-037-003)the Ministry of Health and Welfare(MOHW113-TDU-B-222-134014)+3 种基金funded by the health and welfare surcharge of on tobacco products,and the Kaohsiung Medical University Hospital(KMUH113-3R31,KMUH113-3R32,KMUH113-3R33,KMUH113-3M58,KMUH113-3M59,KMUH-S11412,KMUH-SH11403)Kaohsiung Medical University Research Center Grant(KMU-TC113A04)National Tsing Hua University-Kaohsiung Medical University Joint Research Project(NTHU-KMU-KT114P008)supported by the Grant of Taiwan Precision Medicine Initiative and Taiwan Biobank,Academia Sinica,Taiwan.
文摘Background:The long-term outcomes of robotic-assisted surgery and the prognostic significance of the pretreatment neutrophil-to-lymphocyte ratio(NLR)in locally advanced rectal cancer(LARC)remain uncertain.This study aimed to assess the long-term outcomes of patients with LARC undergoing robotic-assisted surgery and to determine the prognostic value of pretreatment NLR.Methods:We retrospectively reviewed 252 patients with LARC who were treated at a single medical center in Taiwan between January 2012 and January 2023.All patients underwent neoadjuvant concurrent chemoradiotherapy(CRT)followed by robotic-assisted surgery with total mesorectal excision(TME).Patients were stratified into four groups on the basis of pretreatment NLRs and carcinoembryonic antigen(CEA)levels.Univariate and multivariate analyses were conducted to identify prognostic indicators for overall survival(OS)and disease-free survival(DFS).Results:Patients with a pretreatment NLR of≥3.2 exhibited significantly worse OS and DFS compared with those with an NLR of<3.2(OS:94.4 vs.116.5 months,p=0.001;DFS:78.8 vs.101.7 months,p=0.003).Group A exhibited the poorest prognosis,whereas Group D had the most favorable outcomes.Multivariate analysis revealed NLR≥3.2 as an independent predictor of poor OS(hazard ratio[HR]=2.306,95%CI:1.149-3.747;p=0.001)and DFS(HR=2.055,95%CI:1.341-3.148;p=0.001).Conclusion:Neoadjuvant concurrent CRT followed by robotic-assisted TME is an effective treatment strategy for LARC.A higher pretreatment NLR(≥3.2)independently predicted worse OS and DFS.Stratification using the NLR in combination with CEA levels may enhance prognostic accuracy for patients undergoing robotic-assisted surgery for LARC.
基金a phased research outcome report of the Major Innovation Project of the Chinese Academy of Social Sciences,“Research on Major Issues in Improving the Mechanisms and Institutions for Integrated Urban-Rural Development”(Project No. 2024YZD008)。
文摘The promotion of rural revitalization within the ecological conservation areas(“ECAs”) requires a careful balance between ecological protection and economic development and should be guided by the principle of ecological priority. The cultivation of rural “Local Specialty Products”(“LSPs”) under a green-development framework aligns with the functional positioning of these areas, drives the revitalization of rural industries, and constitutes a fundamental strategy for addressing the unique challenges they face. Although ECAs possess inherent advantages in terms of developing LSPs, they are also confronted by multiple constraints. Accordingly, we propose development objectives that emphasize(a) driving rural industrial prosperity,(b) enhancing the appeal of agricultural heritage, and(c) ensuring inclusive prosperity in the farming communities. In selecting pathways for growth, priority should be given to improving the quality of products, fostering distinctiveness of the technologies, nurturing cultural identities, and upholding the principle of common prosperity. From a policy standpoint, the development of rural LSPs should be recognized as a key lever for advancing the comprehensiveness of rural revitalization in the ECAs. We recommend a set of supportive measures—namely, reinforcing the guidance for spatial planning, integrating the consolidation of factor inputs, and ensuring the robustness of organizational guarantees—to facilitate the high-quality development of LSPs in these areas.
基金supported by the following projects:National Natural Science Foundation of China[U24A20135]Science and Technology Program of the State Administration for Market Regulation[2024MK016]+9 种基金Basic Scientific Research Fund Project for Higher Education Institutions of Inner Mongolia(2024YXXS057)Key Project of Natural Science Foundation of Inner Mongolia[2023ZD12]2023 Inner Mongolia Autonomous Region Key R&D and Achievement Transformation Program[2023YFHH0090]Natural Science Foundation of Inner Mongolia[2022MS05006]Talent Development Fund of Inner Mongolia Autonomous RegionFundamental Research Funds for Universities[2023RCTD012]Fundamental Research Funds for Universities[2023QNJS075]Inner Mongolia Autonomous Region Postgraduate Research Innovation Project[KC2024053B]Fundamental Research Funds for Universities[2024YXXS012]Open Project of the National Key Laboratory of Special Vehicle Design and Manufacturing Integration Technology[GZ2023KF012].
文摘In ultrasonic non-destructive testing of high-temperature industrial equipment,sound velocity drift induced by non-uniform temperature fields can severely compromise defect localization accuracy.Conventional approaches that rely on room-temperature sound velocities introduce systematic errors,potentially leading to misjudgment of safety-critical components.Two primary challenges hinder current methods:first,it is difficult to monitor real-time changes in sound velocity distribution within a thermal gradient;second,traditional uniform-temperature correction models fail to capture the nonlinear dependence of material properties on temperature and their effect on ultrasonic velocity fields.Here,we propose a defect localization correction method based on multiphysics coupling.A two-dimensional coupled heat transfer–wave propagation model is established in COMSOL,and a one-dimensional steady-state heat transfer condition is used to design a numerical pulse–echo experiment in 1020 steel.Temperature-dependent material properties are incorporated,and the intrinsic relationship between sound velocity and temperature is derived,confirming consistency with classical theories.To account for gradient temperature fields,a micro-element integration algorithm discretizes the propagation path into segments,each associated with a locally computed temperature from the steady-state heat conduction solution.Defect positions are dynamically corrected through cumulative displacement along the propagation path.By integrating heat conduction and elastic wave propagation in a multiphysics framework,this method overcomes the limitations of uniform-temperature assumptions.The micro-element integration approach enables dynamic tracking of spatially varying sound velocities,offering a robust strategy to enhance ultrasonic testing accuracy in high-temperature industrial environments.
基金supported by the National Natural Science Foundation of China(Grant No.52339001).
文摘To investigate the damage evolution caused by stress-driven and sub-critical crack propagation within the Beishan granite under multi-creep triaxial compressive conditions,the distributed optical fiber sensing and X-ray computed tomography were combined to obtain the strain distribution over the sample surface and internal fractures of the samples.The Gini and skewness(G-S)coefficients were used to quantify strain localization during tests,where the Gini coefficient reflects the degree of clustering of elements with high strain values,i.e.,strain localization/delocalization.The strain localization-induced asymmetry of data distribution is quantified by the skewness coefficient.A precursor to granite failure is defined by the rapid and simultaneous increase of the G-S coefficients,which are calculated from strain increment,giving an earlier warning of failure by about 8%peak stress than those from absolute strain values.Moreover,the process of damage accumulation due to stress-driven crack propagation in Beishan granite is different at various confining pressures as the stress exceeds the crack initiation stress.Concretely,strain localization is continuous until brittle failure at higher confining pressure,while both strain localization and delocalization occur at lower confining pressure.Despite the different stress conditions,a similar statistical characteristic of strain localization during the creep stage is observed.The Gini coefficient increases,and the skewness coefficient decreases slightly as the creep stress is below 95%peak stress.When the accelerated strain localization begins,the Gini and skewness coefficients increase rapidly and simultaneously.
基金supported by the National Key R&D Program of China(Grant No.2022YFE0207300)the National Natural Science Foundation of China(Grant Nos.22179142 and 22075314)+1 种基金Jiangsu Provincial Science and Technology Program(Grant No.BG 2024020).XPSWAXS and TOF-SIMS characterizations were supported by Nano-X(Vacuum Interconnected Nanotech Workstation,Suzhou Institute of Nano-Tech and Nano-Bionics,Chinese Academy of Sciences(SINANO),Suzhou 215123,China)。
文摘The practical application of lithium metal batteries(LMBs)requires electrolytes that simultaneously ensure high safety and interfacial stability.Although locally concentrated ionic liquid electrolytes(LCILEs)exhibit exceptional electrochemical stability and compatibility with electrode electrolyte interfaces(EEIs),two major challenges persist:(i)safety risks caused by excessive low-flash-point diluents,and(ii)insufficient understanding of how diluents modulate solvation structures.Herein,we introduce a low-diluent-content LCILE system composed of lithium bis(fluorosulfonyl)imide(LiFSI)salt,N-methyl-N-propyl-pyrrolidinium bis(fluorosulfonyl)imide(Pyr_(13)FSI)ionic liquid,and trifluoromethanesulfonate(TFS)diluent.The TFS diluent strengthens ion-ion interactions by lowering the dielectric constant of the electrolyte,resulting in the formation of a unique nanometric anion aggregates(N-AGGs)reinforced solvation structure.These large anionic clusters exhibit accelerated redox decomposition kinetics,facilitating the rapid formation of a thin,dense,and low-impedance EEI.Consequently,the Li/LiNi_(0.6)Co_(0.2)Mn_(0.2)O_(2)coin cell achieves 87.8%capacity retention over 300 cycles at 4.3 V,while a practical 1.4 Ah Li/NCM622 pouch cell retains 84.5%capacity after 80 cycles at 4.5 V.Furthermore,the electrolyte demonstrates exceptional safety,and 2 Ah Li metal pouch cells successfully pass rigorous nail penetration tests without any ignition or explosion.This work not only provides a design strategy for intrinsically safe and high-performance electrolytes but also highlights the critical role of anion cluster decomposition kinetics in shaping EEI formation.
基金supported by the NSFC(12301115)the Natural Science Foundation of Huzhou(2023YZ11,2024YZ37)the second author was supported by the NSFC(12071437).
文摘It is well known that the inhomogeneous Calderón-Zygmund convolution operators are bounded on the local Hardy spaces.In this paper,we prove that these operators are bounded on the local product Hardy spaces and the Lipschitz spaces.The key ideas used here are the discrete local Calderón identity and a density argument for the inhomogeneous product Lipschitz spaces in the weak sense.
基金Supported by NSFC(Nos.11661025,12161024)Natural Science Foundation of Guangxi(Nos.2020GXNSFAA159118,2021GXNSFAA196045)+2 种基金Guangxi Science and Technology Project(No.Guike AD20297006)Training Program for 1000 Young and Middle-aged Cadre Teachers in Universities of GuangxiNational College Student's Innovation and Entrepreneurship Training Program(No.202110595049)。
文摘In this paper,we present local functional law of the iterated logarithm for Cs?rg?-Révész type increments of fractional Brownian motion.The results obtained extend works of Gantert[Ann.Probab.,1993,21(2):1045-1049]and Monrad and Rootzén[Probab.Theory Related Fields,1995,101(2):173-192].
基金supported by the National Key Re-search&Development Plan of China(No.2020YFA0405900)the Major Research Plan of the National Natural Science Foundation of China(No.92263201)Y.P.Xia would like to thank the support by the Jiangsu Funding Program for Excellent Postdoctoral Talent.All authors thank the Advanced Material Research Institute of Jiangsu Industrial Technology Research Institute(JITRI,Suzhou,China)for the experimental support.
文摘Laser-welded Ti-6Al-4 V is prone to severe residual stresses,microstructural variation,and structural de-fects which are known detrimental to the mechanical properties of weld joints.Residual stress removal is typically applied to weld joints for engineering purposes via heat treatment,in order to avoid prema-ture failure and performance degradation.In the present work,we found that proper welding residual stresses in laser-welded Ti-6Al-4 V sheets can maintain better ductility during uniaxial tension,as op-posed to the stress-relieved counterparts.A detailed experimental investigation has been performed on the deformation behaviours of Ti-6Al-4 V butt welds,including residual stress distribution characteriza-tions by focused ion beam ring-coring coupled with digital image correlation(FIB-DIC),X-ray comput-erized tomography(CT)for internal voids,and in-situ DIC analysis of the subregional strain evolutions.It was found that the pores preferentially distributed near the fusion zone(FZ)boundary,where the compressive residual stress was up to-330 MPa.The removal of residual stress resulted in a changed failure initiation site from the base material to the FZ boundary,the former with ductile and the latter with brittle fracture characteristics under tensile deformation.The combined effects of residual stresses,microstructures,and internal pores on the mechanical responses are discussed in detail.This work high-lights the importance of inevitable residual stress and pores in laser weld pieces,leading to key insights for post-welding treatment and service performance evaluations.
文摘The proposed hybrid optimization algorithm integrates particle swarm optimizatio(PSO)with Ant Colony Optimization(ACO)to improve a number of pitfalls within PSO methods traditionally considered and/or applied to industrial robots.Particle Swarm Optimization may frequently suffer from local optima and inaccuracies in identifying the geometric parameters,which are necessary for applications requiring high-accuracy performances.The proposed approach integrates pheromone-based learning of ACO with the D-H method of developing an error model;hence,the global search effectiveness together with the convergence accuracy is further improved.Comparison studies of the hybrid PSO-ACO algorithm show higher precision and effectiveness in the optimization of geometric error parameters compared to the traditional methods.This is a remarkable reduction of localization errors,thus yielding accuracy and reliability in industrial robotic systems,as the results show.This approach improves performance in those applications that demand high geometric calibration by reducing the geometric error.The paper provides an overview of input for developing robotics and automation,giving importance to precision in industrial engineering.The proposed hybrid methodology is a good way to enhance the working accuracy and effectiveness of industrial robots and shall enable their wide application to complex tasks that require a high degree of accuracy.
基金financial support from the National Natural Science Foundation of China(Nos.52104306,52274301,52334009)the Aeronautical Science Foundation of China(No.2023Z0530S6005)+3 种基金the National Key Research and Development Program of China(No.2023YFB3712401)the Science and Technology Commission of Shanghai Municipality(No.21DZ1208900)the Academician Workstation of Kunming University of Science and Technology(2024),the Ningbo Yongjiang Talent-Introduction Programme(No.2022A-023-C)the Zhejiang Phenomenological Materials Technology Co.,Ltd.,China.
文摘A multi-phase heterogeneous FeCoNi-based high-entropy alloy is developed to overcome the trade-off between strength and ductility.By alloying with a small amount of Cu and employing a rapid recrystalliza-tion process,it exhibits a good combination of yield strength(roughly 1300 MPa)and ductility(approach-ing 20%).Firstly,a multi-phase heterogeneous structure is tailored ranging from nano to micron.Cu is efficiently precipitated as nanoscale clusters(4.2 nm),high-density cuboidal L1_(2) particles(20-40 nm)and L2_(1) particles(500-800 nm)are found to be embedded in the matrix and a bimodal heterogeneous grain structure(1-40μm)is constructed.Secondly,the introduction of Cu effectively suppresses the pre-cipitation of coarse L21 phase at grain boundaries,reducing its volume fraction by 80%and replaced by smaller-scale continuous precipitations within the grains.Thirdly,the high mixing enthalpy gap of Cu and the matrix leads to the formation of local chemical fluctuation and the consequential rugged topog-raphy in the matrix,which result in retarded dislocation motion and promotes dislocation plugging and interlocking during strain,enhancing yield stress and work hardening rate.This study provides a valuable perspective to enhance strength and ductility via enlarged local chemical fluctuation-tailored multi-phase heterogeneous structures.
基金funded by the Youth Fund of the National Natural Science Foundation of China(Grant No.42261070).
文摘Spectrum-based fault localization (SBFL) generates a ranked list of suspicious elements by using the program execution spectrum, but the excessive number of elements ranked in parallel results in low localization accuracy. Most researchers consider intra-class dependencies to improve localization accuracy. However, some studies show that inter-class method call type faults account for more than 20%, which means such methods still have certain limitations. To solve the above problems, this paper proposes a two-phase software fault localization based on relational graph convolutional neural networks (Two-RGCNFL). Firstly, in Phase 1, the method call dependence graph (MCDG) of the program is constructed, the intra-class and inter-class dependencies in MCDG are extracted by using the relational graph convolutional neural network, and the classifier is used to identify the faulty methods. Then, the GraphSMOTE algorithm is improved to alleviate the impact of class imbalance on classification accuracy. Aiming at the problem of parallel ranking of element suspicious values in traditional SBFL technology, in Phase 2, Doc2Vec is used to learn static features, while spectrum information serves as dynamic features. A RankNet model based on siamese multi-layer perceptron is constructed to score and rank statements in the faulty method. This work conducts experiments on 5 real projects of Defects4J benchmark. Experimental results show that, compared with the traditional SBFL technique and two baseline methods, our approach improves the Top-1 accuracy by 262.86%, 29.59% and 53.01%, respectively, which verifies the effectiveness of Two-RGCNFL. Furthermore, this work verifies the importance of inter-class dependencies through ablation experiments.
基金financially supported by the National Key Research and Development Program of China (Grant No. 2021YFB2601100)the National Natural Science Foundation of China (Grant No. 51979190)。
文摘Under the combination of currents and waves, seabed scour occurs around offshore wind turbine foundations, which affects the stability and safe operation of offshore wind turbines. In this study, physical model experiments under unidirectional flow, bidirectional flow, and wave-current interactions with different flow directions around the pile group foundation were first conducted to investigate the development of scour around the pile group foundation.Additionally, a three-dimensional scour numerical model was established via the open-source software REEF3D to simulate the flow field and scour around the prototype-scale foundation. The impact of flow on scour was discussed.Under unidirectional flow, scour equilibrium was reached more quickly, with the maximum scour depth reaching approximately 1.2 times the pile diameter and the extent of the scour hole spanning about 4.9 times the pile diameter.Compared with those under unidirectional flow, the scour depths under combinations of currents and waves, as well as bidirectional flow, were slightly smaller. However, the morphology of scour holes was more uniform and symmetrical. The numerical simulation results show good agreement with the experimental data, demonstrating the impact of varying flow directions on the velocity distribution around the foundation, the morphology of scour holes, and the location of the maximum scour depth.
