Ceramic-reinforced metal matrix composites(MMCs)display beneficial properties owing to their combination of ceramic and metal phases.However,the properties are highly dependent on the reinforcing phase composition,vol...Ceramic-reinforced metal matrix composites(MMCs)display beneficial properties owing to their combination of ceramic and metal phases.However,the properties are highly dependent on the reinforcing phase composition,volume fraction and morphology.Continuous fiber or network reinforcement morphologies are difficult and expensive to manufacture,and the often-used discontinuous particle or whisker reinforcement morphologies result in less effective properties.Here,we demonstrate the formation of a co-continuous ceramic-reinforced metal matrix composite using solid-state processing.Binder jet additive manufacturing(BJAM)was used to print a nickel superalloy part followed by post-processing via reactive sintering to form a continuous carbide reinforcing phase at the particle boundaries.The kinetics of reinforcement formation are investigated in order to develop a relationship between reactive sintering time,temperature and powder composition on the reinforcing phase thickness and volume fraction.To evaluate performance,the wear resistance of the reinforced BJAM alloy 625 MMC was compared to unreinforced BJAM alloy 625,demonstrating a 64%decrease in the specific wear rate under abrasive wear conditions.展开更多
In this paper,we consider the maximal positive definite solution of the nonlinear matrix equation.By using the idea of Algorithm 2.1 in ZHANG(2013),a new inversion-free method with a stepsize parameter is proposed to ...In this paper,we consider the maximal positive definite solution of the nonlinear matrix equation.By using the idea of Algorithm 2.1 in ZHANG(2013),a new inversion-free method with a stepsize parameter is proposed to obtain the maximal positive definite solution of nonlinear matrix equation X+A^(*)X|^(-α)A=Q with the case 0<α≤1.Based on this method,a new iterative algorithm is developed,and its convergence proof is given.Finally,two numerical examples are provided to show the effectiveness of the proposed method.展开更多
Driven by advancements in mobile internet technology,images have become a crucial data medium.Ensuring the security of image information during transmission has thus emerged as an urgent challenge.This study proposes ...Driven by advancements in mobile internet technology,images have become a crucial data medium.Ensuring the security of image information during transmission has thus emerged as an urgent challenge.This study proposes a novel image encryption algorithm specifically designed for grayscale image security.This research introduces a new Cantor diagonal matrix permutation method.The proposed permutation method uses row and column index sequences to control the Cantor diagonal matrix,where the row and column index sequences are generated by a spatiotemporal chaotic system named coupled map lattice(CML).The high initial value sensitivity of the CML system makes the permutation method highly sensitive and secure.Additionally,leveraging fractal theory,this study introduces a chaotic fractal matrix and applies this matrix in the diffusion process.This chaotic fractal matrix exhibits selfsimilarity and irregularity.Using the Cantor diagonal matrix and chaotic fractal matrix,this paper introduces a fast image encryption algorithm involving two diffusion steps and one permutation step.Moreover,the algorithm achieves robust security with only a single encryption round,ensuring high operational efficiency.Experimental results show that the proposed algorithm features an expansive key space,robust security,high sensitivity,high efficiency,and superior statistical properties for the ciphered images.Thus,the proposed algorithm not only provides a practical solution for secure image transmission but also bridges fractal theory with image encryption techniques,thereby opening new research avenues in chaotic cryptography and advancing the development of information security technology.展开更多
We read with the great interest the study by Ababneh et al in which inducedmesenchymal stem cell-derived exosomes were shown to exhibit a stronger andmore sustained anti-proliferative effect by inducing a senescence-l...We read with the great interest the study by Ababneh et al in which inducedmesenchymal stem cell-derived exosomes were shown to exhibit a stronger andmore sustained anti-proliferative effect by inducing a senescence-like state withoutapoptosis.The results obtained by the authors highlight the features of theeffects of senescent drift induction in surrounding tissues.In the light of thesefindings,the role of the properties of extracellular matrix and cellular glycocalyxin responses of human tumors to therapy remain uninvestigated.These extracellularbarriers appear to be significant obstacles to effective cancer therapy,especiallyin relation to the use of unique properties of tumor microenvironment forthe immunotherapy-resistant cancer treatment.展开更多
The effect of adding hydroxycinnamic acids(caffeic acid,sinapic acid,p-coumaric acid and chlorogenic acid)in Cabernet Sauvignon dry red wine before and after fermentation was investigated,taking into account the color...The effect of adding hydroxycinnamic acids(caffeic acid,sinapic acid,p-coumaric acid and chlorogenic acid)in Cabernet Sauvignon dry red wine before and after fermentation was investigated,taking into account the color parameters,anthocyanin content,and overall polyphenol levels in the wine samples.The copigmentation effect of malvidin-3-Oglucoside and sinapic acid was further explored in model solution and through theoretical calculations.The results indicated that the addition of hydroxycinnamic acids significantly enhanced the wine's color with sinapic acid(before the fermentation)showing the most pronounced color protection effect.Compared to control samples,the addition of hydroxycinnamic acids resulted in a 36%increase in total phenolic content and a 28% increase in total anthocyanin content.Thermodynamic analysis revealed that the interaction between sinapic acid and malvidin-3-O-glucoside was spontaneous and exothermic.Theoretical studies identified hydrogen bonding(HB)and dispersion forces as the main primary stabilizing forces,with the carboxyl group of sinapic acid playing a critical role while the anthocyanin backbone also influenced the interaction.展开更多
The fast solution of linear equations has always been one of the hot spots in scientific computing.A kind of the diagonal matrix splitting iteration methods are provided,which is different from the classical matrix sp...The fast solution of linear equations has always been one of the hot spots in scientific computing.A kind of the diagonal matrix splitting iteration methods are provided,which is different from the classical matrix splitting methods.Taking the decomposition of the diagonal elements for coefficient matrix as the key point,some new preconditioners are constructed.Taking the tri-diagonal coefficient matrix as an example,the convergence domains and optimal relaxation factor of the new method are analyzed theoretically.The presented new iteration methods are applied to solve linear algebraic equations,even 2D and 3D diffusion problems with the fully implicit discretization.The results of numerical experiments are matched with the theoretical analysis,and show that the iteration numbers are reduced greatly.The superiorities of presented iteration methods exceed some classical iteration methods dramatically.展开更多
Evaluating the adversarial robustness of classification algorithms in machine learning is a crucial domain.However,current methods lack measurable and interpretable metrics.To address this issue,this paper introduces ...Evaluating the adversarial robustness of classification algorithms in machine learning is a crucial domain.However,current methods lack measurable and interpretable metrics.To address this issue,this paper introduces a visual evaluation index named confidence centroid skewing quadrilateral,which is based on a classification confidence-based confusion matrix,offering a quantitative and visual comparison of the adversarial robustness among different classification algorithms,and enhances intuitiveness and interpretability of attack impacts.We first conduct a validity test and sensitive analysis of the method.Then,prove its effectiveness through the experiments of five classification algorithms including artificial neural network(ANN),logistic regression(LR),support vector machine(SVM),convolutional neural network(CNN)and transformer against three adversarial attacks such as fast gradient sign method(FGSM),DeepFool,and projected gradient descent(PGD)attack.展开更多
This study investigates the anisotropic thermal conductivity of aluminum matrix composites reinforced with graphene nano-plates(GNPs)and in situ ZrB_(2) nanoparticles,while simultaneously maintaining high strength and...This study investigates the anisotropic thermal conductivity of aluminum matrix composites reinforced with graphene nano-plates(GNPs)and in situ ZrB_(2) nanoparticles,while simultaneously maintaining high strength and toughness.A discontinuous layered GNPs-ZrB_(2)/AA6111 composite was prepared using in situ melt reactions and semi-solid stirring casting technology,combined with hot rolling deformation processing.Microstructural analysis revealed that the GNPs were aligned parallel to the rolling direction-transverse direction(RD-TD)plane,whereas the ZrB_(2) nanoparticles aggregated into cluster strips,collectively forming a discontinuous layered structure.This multilayer arrangement maximized the in-plane thermal conductivity of the GNPs.The tightly bonded GNP/Al interfaces with the locking of CuAl_(2) nanoparticles ensured that the GNPs fully exploited their high thermal conductivity.Therefore,the GNPs-ZrB_(2)/AA6111 composite achieved high in-plane thermal conductivity(230 W/(m·K)),which is higher than that of the matrix(206 W/(m·K)).The improved in-plane thermal conductivity is primarily attributed to the exceptionally high intrinsic in-plane thermal conductivity of the GNPs and their two-dimensional layered structure.However,the composite exhibited pronounced thermal conductivity anisotropy in the in-plane and through-plane directions.The reduced through-plane thermal conductivity is predominantly caused by the intrinsically low through-plane thermal conductivity of the GNPs and the increased interfacial thermal resistance from the additional grain boundaries.展开更多
Polymer matrix composites with high dielectric constants and low dielectric losses are in high demand for flexible electronics.However,simultaneously satisfying these requirements poses a significant scientific challe...Polymer matrix composites with high dielectric constants and low dielectric losses are in high demand for flexible electronics.However,simultaneously satisfying these requirements poses a significant scientific challenge owing to the intrinsic trade-off relationship.Herein,we utilized the in situ controllable reduction of graphene oxide(GO)within a poly(vinylidene fluoride-trifluoroethylene-chlorofluoroethylene)(P(VDF-Tr FE-CFE))matrix to regulate the dielectric properties.The as-obtained composite exhibited a high relative dielectric constant of 1415coupled with a low loss tangent of 0.380 at 100 Hz.Experimental and theoretical studies indicate that the increased degree of electron conjugation and conductivity of the reduced GO(RGO)are responsible for the high-k.The constrained reduction degree of GO,combined with its homogeneous dispersion in the polymer matrix,effectively suppresses long-range charge carrier migration,thereby minimizing dielectric loss.This novel strategy could be successfully applied to both organic and aqueous systems.Furthermore,a high-performance flexible capacitive proximity sensor was exemplified by the optimization of both the dielectric layer and electrode pattern,exhibiting excellent sensitivity and stability.The fundamental mechanisms elucidated in this study provide crucial design principles for developing dielectric PMCs with tailored properties,thereby opening new avenues for advanced flexible electronic applications.展开更多
Peripheral nerve injury causes severe neuroinflammation and has become a global medical challenge.Previous research has demonstrated that porcine decellularized nerve matrix hydrogel exhibits excellent biological prop...Peripheral nerve injury causes severe neuroinflammation and has become a global medical challenge.Previous research has demonstrated that porcine decellularized nerve matrix hydrogel exhibits excellent biological properties and tissue specificity,highlighting its potential as a biomedical material for the repair of severe peripheral nerve injury;however,its role in modulating neuroinflammation post-peripheral nerve injury remains unknown.Here,we aimed to characterize the anti-inflammatory properties of porcine decellularized nerve matrix hydrogel and their underlying molecular mechanisms.Using peripheral nerve injury model rats treated with porcine decellularized nerve matrix hydrogel,we evaluated structural and functional recovery,macrophage phenotype alteration,specific cytokine expression,and changes in related signaling molecules in vivo.Similar parameters were evaluated in vitro using monocyte/macrophage cell lines stimulated with lipopolysaccharide and cultured on porcine decellularized nerve matrix hydrogel-coated plates in complete medium.These comprehensive analyses revealed that porcine decellularized nerve matrix hydrogel attenuated the activation of excessive inflammation at the early stage of peripheral nerve injury and increased the proportion of the M2 subtype in monocytes/macrophages.Additionally,porcine decellularized nerve matrix hydrogel negatively regulated the Toll-like receptor 4/myeloid differentiation factor 88/nuclear factor-κB axis both in vivo and in vitro.Our findings suggest that the efficacious anti-inflammatory properties of porcine decellularized nerve matrix hydrogel induce M2 macrophage polarization via suppression of the Toll-like receptor 4/myeloid differentiation factor 88/nuclear factor-κB pathway,providing new insights into the therapeutic mechanism of porcine decellularized nerve matrix hydrogel in peripheral nerve injury.展开更多
The development of shape-customizable and bulk flexible electrochemical devices through processing technologies as versatile as those used for plastics promises to revolutionize the future of battery technology.Howeve...The development of shape-customizable and bulk flexible electrochemical devices through processing technologies as versatile as those used for plastics promises to revolutionize the future of battery technology.However,this pursuit has been fundamentally hindered by the absence of transformative battery materials capable of delivering the necessary electrochemical functions,robust interface adhesion,and,crucially,the suitable rheological properties required for on-demand shaping.In this work,we introduce a concept of a multifunctional plasticine electrode matrix(PEM)featuring nano-interpenetrating networks(nano-IPN)to address this challenge.Utilizing the nonflammable liquid-electrolyte hydration combined with conductive nanomaterials,we have realized a PEM in the form of a multifunctional nanocomposite that integrates ion and electron conduction,component binding,non-flammability,and plasticine-like moldability.With this PEM,we have successfully fabricated a variety of bulk-flexible electrodes with high mass loading of active material(AM)(>70 wt%)using industry-friendly extrusion and compression molding techniques.Moreover,these high AM-loading composite electrodes achieve an unparalleled bulk conformability and flexibility,remaining structurally intact even under severe mechanical stress.Ultimately,we have successfully produced shape-patternable and flexible batteries via extrusion molding.This study underscores the potential of the PEM to revolutionize battery microstructures,interfaces,manufacturing processes,and performance characteristics.展开更多
Objective:Osteoarthritis(OA)is a degenerative joint disease characterized by extracellular matrix(ECM)degradation,chondrocyte apoptosis,and chronic inflammation.Cartilage destruction and ECM degeneration contribute to...Objective:Osteoarthritis(OA)is a degenerative joint disease characterized by extracellular matrix(ECM)degradation,chondrocyte apoptosis,and chronic inflammation.Cartilage destruction and ECM degeneration contribute to joint function loss and disability.Signal transducer and activator of transcription 3(STAT3)up-regulates the expression of MMP-13,which degrades collagen Ⅱ.Our previous study found that 5,7,3',4'-tetramethoxyflavone(TMF)exhibited protective effects on OA chondrocytes.This study aims to investigate the protective role of TMF in inhibiting ECM degradation by mediating the Sirt1/STAT3 signaling pathway.Methods:Rat OA models were established by the injection of monosodium iodoacetate(MIA).Hematoxylin&eosin(HE)staining and immunohistochemistry(IHC)analysis were performed.IL-1β stimulated C28/I2 cells were used as OA-like chondrocyte cell model.Western blotting assays were used to determine the protein expression.Results:The expression of MMP-13 was upregulated while type Ⅱ collagen expression is downregulated,and the phosphorylation level of STAT3 is increased in rat OA models.TMF reverses the STAT3-mediated expression of MMP-13 and type v collagen.Activation of STAT3 or inhibition of Sirt1 function attenuates the inhibitory effect of TMF on ECM degradation.Conclusion:TMF can inhibit ECM degradation mediated by the STAT3 signal pathway by activating Sirt1 expression in OA cell and animal models.展开更多
Objectives:High-grade serous ovarian cancer(HGSOC),the most common subtype of epithelial ovarian cancer(EOC),exhibits a mesenchymal phenotype characterized by fibrotic stroma and poor prognosis.Human epididymis protei...Objectives:High-grade serous ovarian cancer(HGSOC),the most common subtype of epithelial ovarian cancer(EOC),exhibits a mesenchymal phenotype characterized by fibrotic stroma and poor prognosis.Human epididymis protein 4(HE4),a key diagnostic biomarker for ovarian cancer,is involved in fibrotic processes in several non-malignant diseases.Given the clinical significance of stromal fibrosis in HGSOC and the potential link between HE4 and fibrosis,this study aimed to investigate the role of HE4 in the formation of stromal fibrosis in HGSOC.Methods:A total of 126 patients with gynecological conditions were included and divided into normal,benign,and EOC groups.Tissue stiffness was quantitatively measured and analyzed for its correlation with clinicopathological features.We further investigated the correlation between tumor stiffness and the expression levels of HE4 and fibroblast activation markers(α-smooth muscle actin(α-SMA)and fibroblast activation protein(FAP))in tumor tissues from 22 HGSOC patients.In vitro,primary fibroblasts were treated with recombinant HE4(rHE4)or conditioned media from HE4-knockdown ovarian cancer cells to assess fibroblasts activation and matrix contractility(Collagen gel contraction assays).In vivo,a subcutaneous xenograft model using HE4-knockdown cells was established to evaluate the effects of HE4 suppression on tumor growth and extensive extracellular matrix(ECM)remodeling.Results:Ovarian cancer tissues showed significantly increased stiffness compared to benign/normal groups,showing positive correlation with serum HE4 levels.High-stiffness HGSOC tumors exhibited upregulated expression of HE4,α-SMA,FAP,and collagen I.rHE4 stimulated fibroblast activation and enhanced matrix contractility,whereas HE4 knockdown in cancer cells abrogated these pro-fibrotic effects.In vivo,HE4-silenced xenografts displayed restricted tumor growth accompanied by reduced stromal expression ofα-SMA,FAP,and collagen I.Conclusion:Our findings suggest that HE4 may facilitate ECM remodeling in HGSOC through promoting fibroblast activation and increasing collagen deposition.展开更多
The mass of high-speed trains can be reduced using the brake disk prepared with SiC network ceramic frame reinforced 6061 aluminum alloy composite （SiCn/Al）. The thermal and stress analyses of SiCn/Al brake disk dur...The mass of high-speed trains can be reduced using the brake disk prepared with SiC network ceramic frame reinforced 6061 aluminum alloy composite （SiCn/Al）. The thermal and stress analyses of SiCn/Al brake disk during emergency braking at a speed of 300 km/h considering airflow cooling were investigated using finite element （FE） and computational fluid dynamics （CFD） methods. All three modes of heat transfer （conduction, convection and radiation） were analyzed along with the design features of the brake assembly and their interfaces. The results suggested that the higher convection coefficients achieved with airflow cooling will not only reduce the maximum temperature in the braking but also reduce the thermal gradients, since heat will be removed faster from hotter parts of the disk. Airflow cooling should be effective to reduce the risk of hot spot formation and disc thermal distortion. The highest temperature after emergency braking was 461 °C and 359 °C without and with considering airflow cooling, respectively. The equivalent stress could reach 269 MPa and 164 MPa without and with considering airflow cooling, respectively. However, the maximum surface stress may exceed the material yield strength during an emergency braking, which may cause a plastic damage accumulation in a brake disk without cooling. The simulation results are consistent with the experimental results well.展开更多
The dry friction and wear behaviors of co-continuous composites SiC/Fe–40Cr against SiC/Al 2618 alloy were investigated on a ring-on-ring friction and wear tester at sliding speed of 30-105 m/s under the load of 1.0-...The dry friction and wear behaviors of co-continuous composites SiC/Fe–40Cr against SiC/Al 2618 alloy were investigated on a ring-on-ring friction and wear tester at sliding speed of 30-105 m/s under the load of 1.0-2.5 MPa. The experimental result reveals that the characteristic of two body abrasive wear and oxidation wear mechanisms are present for SiCn/2618 Al composite under higher load and sliding speed. SiC ceramic continuous network as the reinforcement can avoid composite from the third body wear that usually occurs in traditional particle reinforced composite. The mechanically mixed layer (MML) controls greatly the wear rate and friction coefficient of the composites. The composites tested at higher sliding speed exhibit higher value of friction coefficient and fluctuation, which is associated with the intermittent formation and removal of the MML. The wear and stress—strain behaviors of SiCn/Fe–40Cr against SiCn/Al 2168 at 30-105 m/s under 1.0-2.5 MPa were analyzed by finite element method with the software Solidwork2012 Simulation, respectively. The wear and stress–strain behavior of the composite predicted by the FEM correlated well with the experimental results.展开更多
Magnesium composites reinforced by N-deficient Ti_(2)AlN MAX phase were first fabricated by non-pressure infiltration of Mg into three-dimensional(3D)co-continuous porous Ti_(2)AlN_(x)(x=0.9,1.0)preforms.The relations...Magnesium composites reinforced by N-deficient Ti_(2)AlN MAX phase were first fabricated by non-pressure infiltration of Mg into three-dimensional(3D)co-continuous porous Ti_(2)AlN_(x)(x=0.9,1.0)preforms.The relationship between their mechanical properties and micro-structure is discussed with the assessment of 2D and 3D characterization.X-ray diffraction(XRD)and scanning electron microscopy detected no impurities.The 3D reconstruction shows that the uniformly distributed pores in Ti_(2)AlN_(x) preforms are interconnected,which act as infiltra-tion tunnels for the melt Mg.The compressive yield strength and microhardness of Ti_(2)AlN_(0.9)/Mg are 353 MPa and 1.12 GPa,respectively,which are 8.55%and 6.67%lower than those of Ti_(2)AlN/Mg,respectively.The typical delamination and kink band occurred in Ti_(2)AlN_(x) under compressive and Vickers hardness(V_(H))tests.Owing to the continuous skeleton structure and strong interfacial bonding strength,the crack ini-tiated in Ti_(2)AlN_(x) was blocked by the plastic Mg matrix.This suggests the possibility of regulating the mechanical performance of Ti_(2)AlN/Mg composites by controlling the N vacancy and the hierarchical structure of Ti_(2)AlN skeleton.展开更多
Ti_(2)AlC/TiAl composites with different volume fractions were prepared by hot pressing technology,and their reinforced structural characteristics and mechanical properties were evaluated.The results showed that when ...Ti_(2)AlC/TiAl composites with different volume fractions were prepared by hot pressing technology,and their reinforced structural characteristics and mechanical properties were evaluated.The results showed that when the reinforced phase volume fraction of Ti_(2)AlC was 20%,three-dimensional interpenetrating network structures were formed in the composites.Above 20%,Ti_(2)AlC phase in the composites accumulated and grew to form thick skeletal networks.The microplastic deformation behavior of Ti_(2)AlC phase,such as kink band and delamination,improved the fracture toughness of the composites.Comparative analysis indicated that the uniform and small interconnecting network structures could further reinforce the composites.The bending strengths of composites prepared with 20 vol.%Ti_(2)AlC reached(900.9±45.0)MPa,which was 25.5% higher than that of TiAl matrix.In general,the co-continuous Ti_(2)AlC/TiAl composite with excellent mechanical properties can be prepared by powder metallurgy method.展开更多
Investigation has been made on the process of synthesizing SiC/Al co-continuous composite by spontaneous melt infiltration. It is found that nitrogen atmosphere is an indispensable factor for spontaneous infiltration ...Investigation has been made on the process of synthesizing SiC/Al co-continuous composite by spontaneous melt infiltration. It is found that nitrogen atmosphere is an indispensable factor for spontaneous infiltration of melt Al into SiC preform with continuous porosity. The critical temperature for spontaneous infiltration occurrence can be lowered and spontaneous infiltration rate increased by doping a small amount of Mg into the Al alloy. Adding fine SiO2 powders into the ceramic preform can play the similar role as Mg-doping by increasing wetting through the chemical reaction of 3SiO2+4AI=2Al2O3+3Si at the infiltration front. Infiltration rate can also be increased by Si-doping to lower the viscosity of the molten Al alloy. In addition, sufficient Si content in the molten Al is also indispensable to avoid the formation of Al4C in the synthesized composite.展开更多
基金funding support from the Natural Sciences and Engineering Research Council of Canada(NSERC)the Canada Research Chairs(CRC)Program+1 种基金Huys Industries and the CWB Welding Foundationthe Centre for Advanced Materials Joining and the Multi-Scale Additive Manufacturing Lab at the University of Waterloo。
文摘Ceramic-reinforced metal matrix composites(MMCs)display beneficial properties owing to their combination of ceramic and metal phases.However,the properties are highly dependent on the reinforcing phase composition,volume fraction and morphology.Continuous fiber or network reinforcement morphologies are difficult and expensive to manufacture,and the often-used discontinuous particle or whisker reinforcement morphologies result in less effective properties.Here,we demonstrate the formation of a co-continuous ceramic-reinforced metal matrix composite using solid-state processing.Binder jet additive manufacturing(BJAM)was used to print a nickel superalloy part followed by post-processing via reactive sintering to form a continuous carbide reinforcing phase at the particle boundaries.The kinetics of reinforcement formation are investigated in order to develop a relationship between reactive sintering time,temperature and powder composition on the reinforcing phase thickness and volume fraction.To evaluate performance,the wear resistance of the reinforced BJAM alloy 625 MMC was compared to unreinforced BJAM alloy 625,demonstrating a 64%decrease in the specific wear rate under abrasive wear conditions.
基金Supported in part by Natural Science Foundation of Guangxi(2023GXNSFAA026246)in part by the Central Government's Guide to Local Science and Technology Development Fund(GuikeZY23055044)in part by the National Natural Science Foundation of China(62363003)。
文摘In this paper,we consider the maximal positive definite solution of the nonlinear matrix equation.By using the idea of Algorithm 2.1 in ZHANG(2013),a new inversion-free method with a stepsize parameter is proposed to obtain the maximal positive definite solution of nonlinear matrix equation X+A^(*)X|^(-α)A=Q with the case 0<α≤1.Based on this method,a new iterative algorithm is developed,and its convergence proof is given.Finally,two numerical examples are provided to show the effectiveness of the proposed method.
基金supported by the National Natural Science Foundation of China(62376106)The Science and Technology Development Plan of Jilin Province(20250102212JC).
文摘Driven by advancements in mobile internet technology,images have become a crucial data medium.Ensuring the security of image information during transmission has thus emerged as an urgent challenge.This study proposes a novel image encryption algorithm specifically designed for grayscale image security.This research introduces a new Cantor diagonal matrix permutation method.The proposed permutation method uses row and column index sequences to control the Cantor diagonal matrix,where the row and column index sequences are generated by a spatiotemporal chaotic system named coupled map lattice(CML).The high initial value sensitivity of the CML system makes the permutation method highly sensitive and secure.Additionally,leveraging fractal theory,this study introduces a chaotic fractal matrix and applies this matrix in the diffusion process.This chaotic fractal matrix exhibits selfsimilarity and irregularity.Using the Cantor diagonal matrix and chaotic fractal matrix,this paper introduces a fast image encryption algorithm involving two diffusion steps and one permutation step.Moreover,the algorithm achieves robust security with only a single encryption round,ensuring high operational efficiency.Experimental results show that the proposed algorithm features an expansive key space,robust security,high sensitivity,high efficiency,and superior statistical properties for the ciphered images.Thus,the proposed algorithm not only provides a practical solution for secure image transmission but also bridges fractal theory with image encryption techniques,thereby opening new research avenues in chaotic cryptography and advancing the development of information security technology.
文摘We read with the great interest the study by Ababneh et al in which inducedmesenchymal stem cell-derived exosomes were shown to exhibit a stronger andmore sustained anti-proliferative effect by inducing a senescence-like state withoutapoptosis.The results obtained by the authors highlight the features of theeffects of senescent drift induction in surrounding tissues.In the light of thesefindings,the role of the properties of extracellular matrix and cellular glycocalyxin responses of human tumors to therapy remain uninvestigated.These extracellularbarriers appear to be significant obstacles to effective cancer therapy,especiallyin relation to the use of unique properties of tumor microenvironment forthe immunotherapy-resistant cancer treatment.
基金supported by the Key R&D Program of Shaanxi Province,China(2024NC-YBXM-146)the Xi’an Agricultural Technology Research and Development Project,China(24NYGG0048)+1 种基金the Key R&D Program of Xianyang,China(L2024-ZDYF-ZDYF-NY-0028)the National Foreign Expert Project of China(G2023172002L)。
文摘The effect of adding hydroxycinnamic acids(caffeic acid,sinapic acid,p-coumaric acid and chlorogenic acid)in Cabernet Sauvignon dry red wine before and after fermentation was investigated,taking into account the color parameters,anthocyanin content,and overall polyphenol levels in the wine samples.The copigmentation effect of malvidin-3-Oglucoside and sinapic acid was further explored in model solution and through theoretical calculations.The results indicated that the addition of hydroxycinnamic acids significantly enhanced the wine's color with sinapic acid(before the fermentation)showing the most pronounced color protection effect.Compared to control samples,the addition of hydroxycinnamic acids resulted in a 36%increase in total phenolic content and a 28% increase in total anthocyanin content.Thermodynamic analysis revealed that the interaction between sinapic acid and malvidin-3-O-glucoside was spontaneous and exothermic.Theoretical studies identified hydrogen bonding(HB)and dispersion forces as the main primary stabilizing forces,with the carboxyl group of sinapic acid playing a critical role while the anthocyanin backbone also influenced the interaction.
基金The National Natural Science Foundations of China (12202219)the Natural Science Foundations of Ningxia (2024AAC02009, 2023AAC05001)the Ningxia Youth Top Talents Training Project。
文摘The fast solution of linear equations has always been one of the hot spots in scientific computing.A kind of the diagonal matrix splitting iteration methods are provided,which is different from the classical matrix splitting methods.Taking the decomposition of the diagonal elements for coefficient matrix as the key point,some new preconditioners are constructed.Taking the tri-diagonal coefficient matrix as an example,the convergence domains and optimal relaxation factor of the new method are analyzed theoretically.The presented new iteration methods are applied to solve linear algebraic equations,even 2D and 3D diffusion problems with the fully implicit discretization.The results of numerical experiments are matched with the theoretical analysis,and show that the iteration numbers are reduced greatly.The superiorities of presented iteration methods exceed some classical iteration methods dramatically.
文摘Evaluating the adversarial robustness of classification algorithms in machine learning is a crucial domain.However,current methods lack measurable and interpretable metrics.To address this issue,this paper introduces a visual evaluation index named confidence centroid skewing quadrilateral,which is based on a classification confidence-based confusion matrix,offering a quantitative and visual comparison of the adversarial robustness among different classification algorithms,and enhances intuitiveness and interpretability of attack impacts.We first conduct a validity test and sensitive analysis of the method.Then,prove its effectiveness through the experiments of five classification algorithms including artificial neural network(ANN),logistic regression(LR),support vector machine(SVM),convolutional neural network(CNN)and transformer against three adversarial attacks such as fast gradient sign method(FGSM),DeepFool,and projected gradient descent(PGD)attack.
基金supported by the National Natural Science Foundation of China(Nos.52471156,U20A20274,and 52071158)the China Postdoctoral Science Foundation(Nos.2024M751173 and 2024M752703)+1 种基金the Jiangsu Funding Program for Excellent Postdoctoral Talent,China(No.2024ZB229)the Natural Science Foundation of Jiangsu Higher Education Institutions,China(No.24KJB430012).
文摘This study investigates the anisotropic thermal conductivity of aluminum matrix composites reinforced with graphene nano-plates(GNPs)and in situ ZrB_(2) nanoparticles,while simultaneously maintaining high strength and toughness.A discontinuous layered GNPs-ZrB_(2)/AA6111 composite was prepared using in situ melt reactions and semi-solid stirring casting technology,combined with hot rolling deformation processing.Microstructural analysis revealed that the GNPs were aligned parallel to the rolling direction-transverse direction(RD-TD)plane,whereas the ZrB_(2) nanoparticles aggregated into cluster strips,collectively forming a discontinuous layered structure.This multilayer arrangement maximized the in-plane thermal conductivity of the GNPs.The tightly bonded GNP/Al interfaces with the locking of CuAl_(2) nanoparticles ensured that the GNPs fully exploited their high thermal conductivity.Therefore,the GNPs-ZrB_(2)/AA6111 composite achieved high in-plane thermal conductivity(230 W/(m·K)),which is higher than that of the matrix(206 W/(m·K)).The improved in-plane thermal conductivity is primarily attributed to the exceptionally high intrinsic in-plane thermal conductivity of the GNPs and their two-dimensional layered structure.However,the composite exhibited pronounced thermal conductivity anisotropy in the in-plane and through-plane directions.The reduced through-plane thermal conductivity is predominantly caused by the intrinsically low through-plane thermal conductivity of the GNPs and the increased interfacial thermal resistance from the additional grain boundaries.
基金financially supported by the Innovation and Technology Commission of the Hong Kong SAR Government(No.MRP/020/21)Hong Kong Polytechnic University(No.847A)+1 种基金RI-Wear Seed Fund of Poly U(1-CD8J)Start-up Fund of Poly U(1-BD49)。
文摘Polymer matrix composites with high dielectric constants and low dielectric losses are in high demand for flexible electronics.However,simultaneously satisfying these requirements poses a significant scientific challenge owing to the intrinsic trade-off relationship.Herein,we utilized the in situ controllable reduction of graphene oxide(GO)within a poly(vinylidene fluoride-trifluoroethylene-chlorofluoroethylene)(P(VDF-Tr FE-CFE))matrix to regulate the dielectric properties.The as-obtained composite exhibited a high relative dielectric constant of 1415coupled with a low loss tangent of 0.380 at 100 Hz.Experimental and theoretical studies indicate that the increased degree of electron conjugation and conductivity of the reduced GO(RGO)are responsible for the high-k.The constrained reduction degree of GO,combined with its homogeneous dispersion in the polymer matrix,effectively suppresses long-range charge carrier migration,thereby minimizing dielectric loss.This novel strategy could be successfully applied to both organic and aqueous systems.Furthermore,a high-performance flexible capacitive proximity sensor was exemplified by the optimization of both the dielectric layer and electrode pattern,exhibiting excellent sensitivity and stability.The fundamental mechanisms elucidated in this study provide crucial design principles for developing dielectric PMCs with tailored properties,thereby opening new avenues for advanced flexible electronic applications.
基金supported by the Shenzhen Hong Kong Joint Funding Project,No.SGDX20230116093645007(to LY)the Shenzhen Science and Technology Innovation Committee International Cooperation Project,No.GJHZ20200731095608025(to LY)+7 种基金Shenzhen Development and Reform Commission’s Intelligent Diagnosis,Treatment and Prevention of Adolescent Spinal Health Public Service Platform,No.S2002Q84500835(to LY)Shenzhen Medical Research Fund,No.B2303005(to LY)Team-based Medical Science Research Program,No.2024YZZ02(to LY)Zhejiang Provincial Natural Science Foundation of China,No.LWQ20H170001(to RL)Basic Research Project of Shenzhen Science and Technology from Shenzhen Science and Technology Innovation Commission,No.JCYJ20210324103010029(to BY)Shenzhen Second People’s Hospital Clinical Research Fund of Guangdong Province High-level Hospital Construction Project,Nos.2023yjlcyj029(to BY),2023yjlcyj021(to LL)Guangdong Basic and Applied Basic Research Foundation,No.2022A1515110679(to LL)China Postdoctoral Science Foundation,No.2022M722203(to GL).
文摘Peripheral nerve injury causes severe neuroinflammation and has become a global medical challenge.Previous research has demonstrated that porcine decellularized nerve matrix hydrogel exhibits excellent biological properties and tissue specificity,highlighting its potential as a biomedical material for the repair of severe peripheral nerve injury;however,its role in modulating neuroinflammation post-peripheral nerve injury remains unknown.Here,we aimed to characterize the anti-inflammatory properties of porcine decellularized nerve matrix hydrogel and their underlying molecular mechanisms.Using peripheral nerve injury model rats treated with porcine decellularized nerve matrix hydrogel,we evaluated structural and functional recovery,macrophage phenotype alteration,specific cytokine expression,and changes in related signaling molecules in vivo.Similar parameters were evaluated in vitro using monocyte/macrophage cell lines stimulated with lipopolysaccharide and cultured on porcine decellularized nerve matrix hydrogel-coated plates in complete medium.These comprehensive analyses revealed that porcine decellularized nerve matrix hydrogel attenuated the activation of excessive inflammation at the early stage of peripheral nerve injury and increased the proportion of the M2 subtype in monocytes/macrophages.Additionally,porcine decellularized nerve matrix hydrogel negatively regulated the Toll-like receptor 4/myeloid differentiation factor 88/nuclear factor-κB axis both in vivo and in vitro.Our findings suggest that the efficacious anti-inflammatory properties of porcine decellularized nerve matrix hydrogel induce M2 macrophage polarization via suppression of the Toll-like receptor 4/myeloid differentiation factor 88/nuclear factor-κB pathway,providing new insights into the therapeutic mechanism of porcine decellularized nerve matrix hydrogel in peripheral nerve injury.
基金financial support from the National Natural Science Foundation of China(52473248,52203123,52125301,22279070 and U21A20170)the State Key Laboratory of Polymer Materials Engineering(Grant No:sklpme 2023-1-05 and sklpme 2024-2-04)+3 种基金the Ministry of Science and Technology of China(No.2019YFA0705703)the Sichuan Science and Technology Program(2023NSFSC0991 and 2025ZNSFSC1411)the Fundamental Research Funds for the Central Universitiespartially sponsored by the Double First-Class Construction Funds of Sichuan University.
文摘The development of shape-customizable and bulk flexible electrochemical devices through processing technologies as versatile as those used for plastics promises to revolutionize the future of battery technology.However,this pursuit has been fundamentally hindered by the absence of transformative battery materials capable of delivering the necessary electrochemical functions,robust interface adhesion,and,crucially,the suitable rheological properties required for on-demand shaping.In this work,we introduce a concept of a multifunctional plasticine electrode matrix(PEM)featuring nano-interpenetrating networks(nano-IPN)to address this challenge.Utilizing the nonflammable liquid-electrolyte hydration combined with conductive nanomaterials,we have realized a PEM in the form of a multifunctional nanocomposite that integrates ion and electron conduction,component binding,non-flammability,and plasticine-like moldability.With this PEM,we have successfully fabricated a variety of bulk-flexible electrodes with high mass loading of active material(AM)(>70 wt%)using industry-friendly extrusion and compression molding techniques.Moreover,these high AM-loading composite electrodes achieve an unparalleled bulk conformability and flexibility,remaining structurally intact even under severe mechanical stress.Ultimately,we have successfully produced shape-patternable and flexible batteries via extrusion molding.This study underscores the potential of the PEM to revolutionize battery microstructures,interfaces,manufacturing processes,and performance characteristics.
基金Project Supported by Jiangxi Provincial Natural Science Foundation(20212ACB206002)。
文摘Objective:Osteoarthritis(OA)is a degenerative joint disease characterized by extracellular matrix(ECM)degradation,chondrocyte apoptosis,and chronic inflammation.Cartilage destruction and ECM degeneration contribute to joint function loss and disability.Signal transducer and activator of transcription 3(STAT3)up-regulates the expression of MMP-13,which degrades collagen Ⅱ.Our previous study found that 5,7,3',4'-tetramethoxyflavone(TMF)exhibited protective effects on OA chondrocytes.This study aims to investigate the protective role of TMF in inhibiting ECM degradation by mediating the Sirt1/STAT3 signaling pathway.Methods:Rat OA models were established by the injection of monosodium iodoacetate(MIA).Hematoxylin&eosin(HE)staining and immunohistochemistry(IHC)analysis were performed.IL-1β stimulated C28/I2 cells were used as OA-like chondrocyte cell model.Western blotting assays were used to determine the protein expression.Results:The expression of MMP-13 was upregulated while type Ⅱ collagen expression is downregulated,and the phosphorylation level of STAT3 is increased in rat OA models.TMF reverses the STAT3-mediated expression of MMP-13 and type v collagen.Activation of STAT3 or inhibition of Sirt1 function attenuates the inhibitory effect of TMF on ECM degradation.Conclusion:TMF can inhibit ECM degradation mediated by the STAT3 signal pathway by activating Sirt1 expression in OA cell and animal models.
文摘Objectives:High-grade serous ovarian cancer(HGSOC),the most common subtype of epithelial ovarian cancer(EOC),exhibits a mesenchymal phenotype characterized by fibrotic stroma and poor prognosis.Human epididymis protein 4(HE4),a key diagnostic biomarker for ovarian cancer,is involved in fibrotic processes in several non-malignant diseases.Given the clinical significance of stromal fibrosis in HGSOC and the potential link between HE4 and fibrosis,this study aimed to investigate the role of HE4 in the formation of stromal fibrosis in HGSOC.Methods:A total of 126 patients with gynecological conditions were included and divided into normal,benign,and EOC groups.Tissue stiffness was quantitatively measured and analyzed for its correlation with clinicopathological features.We further investigated the correlation between tumor stiffness and the expression levels of HE4 and fibroblast activation markers(α-smooth muscle actin(α-SMA)and fibroblast activation protein(FAP))in tumor tissues from 22 HGSOC patients.In vitro,primary fibroblasts were treated with recombinant HE4(rHE4)or conditioned media from HE4-knockdown ovarian cancer cells to assess fibroblasts activation and matrix contractility(Collagen gel contraction assays).In vivo,a subcutaneous xenograft model using HE4-knockdown cells was established to evaluate the effects of HE4 suppression on tumor growth and extensive extracellular matrix(ECM)remodeling.Results:Ovarian cancer tissues showed significantly increased stiffness compared to benign/normal groups,showing positive correlation with serum HE4 levels.High-stiffness HGSOC tumors exhibited upregulated expression of HE4,α-SMA,FAP,and collagen I.rHE4 stimulated fibroblast activation and enhanced matrix contractility,whereas HE4 knockdown in cancer cells abrogated these pro-fibrotic effects.In vivo,HE4-silenced xenografts displayed restricted tumor growth accompanied by reduced stromal expression ofα-SMA,FAP,and collagen I.Conclusion:Our findings suggest that HE4 may facilitate ECM remodeling in HGSOC through promoting fibroblast activation and increasing collagen deposition.
基金Projects (50872018, 50902018) supported by the National Natural Science Foundation of ChinaProject (1099043) supported by the Science and Technology in Guangxi Province, ChinaProject (090302005) supported by the Basic Research Fund for Northeastern University, China
文摘The mass of high-speed trains can be reduced using the brake disk prepared with SiC network ceramic frame reinforced 6061 aluminum alloy composite （SiCn/Al）. The thermal and stress analyses of SiCn/Al brake disk during emergency braking at a speed of 300 km/h considering airflow cooling were investigated using finite element （FE） and computational fluid dynamics （CFD） methods. All three modes of heat transfer （conduction, convection and radiation） were analyzed along with the design features of the brake assembly and their interfaces. The results suggested that the higher convection coefficients achieved with airflow cooling will not only reduce the maximum temperature in the braking but also reduce the thermal gradients, since heat will be removed faster from hotter parts of the disk. Airflow cooling should be effective to reduce the risk of hot spot formation and disc thermal distortion. The highest temperature after emergency braking was 461 °C and 359 °C without and with considering airflow cooling, respectively. The equivalent stress could reach 269 MPa and 164 MPa without and with considering airflow cooling, respectively. However, the maximum surface stress may exceed the material yield strength during an emergency braking, which may cause a plastic damage accumulation in a brake disk without cooling. The simulation results are consistent with the experimental results well.
基金Project (2012BAE06B01) supported by the Key Technology R&D Program During the 12th Five-Year Plan Period, ChinaProjects(21201030, 51272039, 51032007) supported by the National Natural Science Foundation of ChinaProject (1099043) supported by the Science and Technology in Guangxi Province, China
文摘The dry friction and wear behaviors of co-continuous composites SiC/Fe–40Cr against SiC/Al 2618 alloy were investigated on a ring-on-ring friction and wear tester at sliding speed of 30-105 m/s under the load of 1.0-2.5 MPa. The experimental result reveals that the characteristic of two body abrasive wear and oxidation wear mechanisms are present for SiCn/2618 Al composite under higher load and sliding speed. SiC ceramic continuous network as the reinforcement can avoid composite from the third body wear that usually occurs in traditional particle reinforced composite. The mechanically mixed layer (MML) controls greatly the wear rate and friction coefficient of the composites. The composites tested at higher sliding speed exhibit higher value of friction coefficient and fluctuation, which is associated with the intermittent formation and removal of the MML. The wear and stress—strain behaviors of SiCn/Fe–40Cr against SiCn/Al 2168 at 30-105 m/s under 1.0-2.5 MPa were analyzed by finite element method with the software Solidwork2012 Simulation, respectively. The wear and stress–strain behavior of the composite predicted by the FEM correlated well with the experimental results.
基金financially supported by the National Natural Science Foundation of China(No.52175284)the State Key Lab of Advanced Metals and Materials(No.2021-ZD08)the Beijing Government Funds for the Cons tructive Project of Central Universities(No.353139535)。
文摘Magnesium composites reinforced by N-deficient Ti_(2)AlN MAX phase were first fabricated by non-pressure infiltration of Mg into three-dimensional(3D)co-continuous porous Ti_(2)AlN_(x)(x=0.9,1.0)preforms.The relationship between their mechanical properties and micro-structure is discussed with the assessment of 2D and 3D characterization.X-ray diffraction(XRD)and scanning electron microscopy detected no impurities.The 3D reconstruction shows that the uniformly distributed pores in Ti_(2)AlN_(x) preforms are interconnected,which act as infiltra-tion tunnels for the melt Mg.The compressive yield strength and microhardness of Ti_(2)AlN_(0.9)/Mg are 353 MPa and 1.12 GPa,respectively,which are 8.55%and 6.67%lower than those of Ti_(2)AlN/Mg,respectively.The typical delamination and kink band occurred in Ti_(2)AlN_(x) under compressive and Vickers hardness(V_(H))tests.Owing to the continuous skeleton structure and strong interfacial bonding strength,the crack ini-tiated in Ti_(2)AlN_(x) was blocked by the plastic Mg matrix.This suggests the possibility of regulating the mechanical performance of Ti_(2)AlN/Mg composites by controlling the N vacancy and the hierarchical structure of Ti_(2)AlN skeleton.
基金the financial supports from the National Natural Science Foundation of China(No.52065009)the Joint Funds of the Science and Technology Foundation of Guizhou Province,China(No.20157219)the Science and Technology Planning Project of Guizhou Province,China(No.20191069).
文摘Ti_(2)AlC/TiAl composites with different volume fractions were prepared by hot pressing technology,and their reinforced structural characteristics and mechanical properties were evaluated.The results showed that when the reinforced phase volume fraction of Ti_(2)AlC was 20%,three-dimensional interpenetrating network structures were formed in the composites.Above 20%,Ti_(2)AlC phase in the composites accumulated and grew to form thick skeletal networks.The microplastic deformation behavior of Ti_(2)AlC phase,such as kink band and delamination,improved the fracture toughness of the composites.Comparative analysis indicated that the uniform and small interconnecting network structures could further reinforce the composites.The bending strengths of composites prepared with 20 vol.%Ti_(2)AlC reached(900.9±45.0)MPa,which was 25.5% higher than that of TiAl matrix.In general,the co-continuous Ti_(2)AlC/TiAl composite with excellent mechanical properties can be prepared by powder metallurgy method.
基金National Natural Sciellce Foundation of China under grant !No. 59601001
文摘Investigation has been made on the process of synthesizing SiC/Al co-continuous composite by spontaneous melt infiltration. It is found that nitrogen atmosphere is an indispensable factor for spontaneous infiltration of melt Al into SiC preform with continuous porosity. The critical temperature for spontaneous infiltration occurrence can be lowered and spontaneous infiltration rate increased by doping a small amount of Mg into the Al alloy. Adding fine SiO2 powders into the ceramic preform can play the similar role as Mg-doping by increasing wetting through the chemical reaction of 3SiO2+4AI=2Al2O3+3Si at the infiltration front. Infiltration rate can also be increased by Si-doping to lower the viscosity of the molten Al alloy. In addition, sufficient Si content in the molten Al is also indispensable to avoid the formation of Al4C in the synthesized composite.
