Let RP（k） denote the k-dimensional real projective space. This article determines which cobordism classes are represented by the total space of a fibering with prescribed base space RP（3）× RP（1）, RP（2） &#...Let RP（k） denote the k-dimensional real projective space. This article determines which cobordism classes are represented by the total space of a fibering with prescribed base space RP（3）× RP（1）, RP（2） × RP（1）, RP（2）× RP（1）× RP（1） or RP（3）× RP（2）.展开更多
UHMWPE fibers exhibit impressive modulus and strength,but they have not reached their theoretical limits.Researchers focus on molecular weight,orientation,and crystallinity of UHMWPE,yet their contributions to mechani...UHMWPE fibers exhibit impressive modulus and strength,but they have not reached their theoretical limits.Researchers focus on molecular weight,orientation,and crystallinity of UHMWPE,yet their contributions to mechanical properties are unclear.Molecular dynamics simulations are valuable but often limited by computational constraints.Our aim is to simulate higher molecular weights to better represent real UHMWPE fibers.We used Packmol and Polyply methodologies to construct PE systems,with Polyply reproducing more reasonable properties of UHMWPE fibers.Additionally,tensile simulations showed that orientation and crystallinity greatly impact Young's modulus more than molecular weight.Energy decomposition indicated that higher molecular weights lead to covalent bonds that can withstand more energy during stretching,thus increasing breaking strength.Combining simulations with machine learning,we found that orientation has the most significant impact on Young's modulus,contributing 60%,and molecular weight plays the most crucial role in determining the breaking strength,accounting for 65%.This study provides a theoretical basis and guidelines for enhancing UHMWPE's modulus and strength.展开更多
The global energy landscape is undergoing a profound transformation,with wind energy,especially wind power,gaining increasing prominence due to its clean,renewable nature.However,as the installed capacity of wind powe...The global energy landscape is undergoing a profound transformation,with wind energy,especially wind power,gaining increasing prominence due to its clean,renewable nature.However,as the installed capacity of wind power continues to expand,the disposal of waste wind turbine blades(WWTB)has emerged as a significant challenge.These blades are predominantly composed of epoxy resin(EP)polymers,carbon fibers(CFs),and glass fibers(GFs).Improper disposal not only exacerbates environmental concerns but also leads to the loss of valuable resources,particularly carbon-based materials.Pyrolysis technology,a versatile and environmentally sustainable method for resource recovery,has garnered considerable attention in the context of WWTB disposal.This work presents a comprehensive review of the pyrolytic recycling of WWTB,focusing on the principles and classifications of pyrolysis technology,key factors influencing the pyrolysis process,as well as the pyrolysis methods,equipment,products,and their applications.Through an in-depth analysis of the current research on the pyrolytic recycling of WWTB,this review identifies critical unresolved issues in the field and provides a forward-looking perspective on emerging research trends.展开更多
We designed and investigated a passive synchronized mode-locked fiber laser.The device utilizes a dual-cavity structure driven by the nonlinear polarization rotation(NPR)mechanism.Stable mode-locking is attained by sy...We designed and investigated a passive synchronized mode-locked fiber laser.The device utilizes a dual-cavity structure driven by the nonlinear polarization rotation(NPR)mechanism.Stable mode-locking is attained by synergistically controlling gain,polarization state,and optical path length in two symmetric sub-cavities.Experiments proved that repetition rate of the sub-cavities can be adjusted via the time delay line(TDL)to achieve synchronized mode-locking.The system stably generates multi-wavelength pulses at a single repetition frequency,evidenced by multiple spectral peaks and equidistant pulse sequences.These findings facilitate the development of high-performance multi-wavelength ultrashort pulse sources,crucial for optical communications,spectral analysis,and remote sensing.展开更多
We report a method for increasing the mechanical strength of carbon nanotube(CNT)fibers while enabling the uniform adhesion of cerium oxide(CeO_(2))abrasive particles to them using polyethyleneimine(PEI).Results show ...We report a method for increasing the mechanical strength of carbon nanotube(CNT)fibers while enabling the uniform adhesion of cerium oxide(CeO_(2))abrasive particles to them using polyethyleneimine(PEI).Results show that 5%of PEI increases the tensile strength of CNT fibers by approximately 175%.CeO_(2) particles were uniformly deposited on the reinforced CNT fibers by electrophoretic deposition.A flexible polishing tool was fabricated by weaving the CeO_(2)-CNT fibers into a non-woven fabric substrate.When used to polish potassium dihydrogen phosphate crystals,the tool reduced the surface roughness from 200 to 7.6 nm within 10 min.This approach has potential use for the development of new precision processing tools.展开更多
To address the challenges of complex metallic film coating processes and low integration in single-parameter detection for existing photonic crystal fiber surface plasmon resonance(PCF-SPR)sensors,a dual-parameter sen...To address the challenges of complex metallic film coating processes and low integration in single-parameter detection for existing photonic crystal fiber surface plasmon resonance(PCF-SPR)sensors,a dual-parameter sensor based on gold nanowire-integrated bias-core PCF-SPR is proposed.Unlike conventional in-hole coatings or metallic film structures,the gold nanowires are directly attached to the fiber cladding via chemical vapor deposition(CVD),eliminating uneven coating issues and significantly simplifying fabrica-tion.By optimizing the asymmetric bias-core fiber structure and leveraging the strong localized field en-hancement of gold nanowires,the sensor achieves high-sensitivity synchronous detection of temperature(25−60℃)and refractive index(1.31−1.40)in dual-polarization modes.The simulation results demonstrate that the x-polarization mode can achieve 1.31−1.40 refractive index detection with maximum wavelength sensitivity and amplitude sensitivity of 14800 nm/RIU and−1724.25 RIU^(−1),and maximum refractive index resolution of 6.75×10^(−6)RIU.The y-polarization mode achieves refractive index detection range of 1.34−1.40,and the maximum wavelength sensitivity and amplitude sensitivity are 28400 nm/RIU and−1298.93 RIU^(−1),and the maximum refractive index resolution is 3.52×10^(−6)RIU.For temperature sensing,the sensor exhibits a wavelength sensitivity of 7.8 nm/℃and a high resolution of 1.38×10^(−6)℃over the range of 25−60℃.This design synergizes gold nanowires and the bias-core architecture to simplify fabrication while enabling multi-parameter detection.The proposed sensor offers new insights for integrated applications in biochemical mon-itoring,environmental sensing,and related fields.展开更多
Silicon carbide fibers are considered ideal reinforcing materials for ceramic matrix composites due to their excellent mechanical properties and high-temperature performance.Different types of fibers necessitate indiv...Silicon carbide fibers are considered ideal reinforcing materials for ceramic matrix composites due to their excellent mechanical properties and high-temperature performance.Different types of fibers necessitate individual investigation due to variations in their composition and fabrication processes.This study presents a comprehensive investigation into evolution of the mechanical properties,surface microstructure,and composition of Shicolon-Ⅱ fibers subjected to argon heat treatment at temperatures ranging from 1300℃to 1700℃.The Shicolon-Ⅱ fibers are composed of small-sized β-SiC grains,SiC_(x)O_(y) amorphous phase,and a minor amount of graphite microcrystals.Following treatment in an argon atmosphere at 1300℃,the fibers maintain a monofilament tensile strength of 3.620 GPa,corresponding to a retention of 98.32%.This strength diminishes to 2.875 GPa,equating to a retention of 78.08%,after treatment at 1500℃.The reduction in mechanical properties of the fibers can be ascribed to the decomposition of the amorphous phase and the growth of β-SiC grains.Furthermore,creep resistance is an essential factor influencing the long-term performance of composite materials.After treatment at temperatures above 1400℃,the high-temperature creep resistance of the fibers is significantly enhanced due to growth of β-SiC grains.This study offers valuable theoretical insights into high-temperature applications of second-generation fibers,contributing to an enhanced understanding of their performance under extreme conditions.展开更多
An alternative elliptical and circle air-hole-assisted Al_(0.24)Ga_(0.76)As photonic crystal fiber(PCF)was proposed for generating broadband high-coherence mid-infrared supercontinuum,and the dispersion,effect-ive mod...An alternative elliptical and circle air-hole-assisted Al_(0.24)Ga_(0.76)As photonic crystal fiber(PCF)was proposed for generating broadband high-coherence mid-infrared supercontinuum,and the dispersion,effect-ive mode area and nonlinear coefficient were investigated by using finite element method(FEM),the evolu-tion of optical pulses propagating along the fiber was simulated,and the supercontinuum and the coherence were analyzed and evaluated under different pumping conditions.The results show that a supercontinuum spectrum with a spectral width of 4.852μm can be obtained in the proposed fiber with d_(1)/Λof 0.125,d_(2)/Λof 0.583 and the zero-dispersion wavelength of 3.228μm by pumping with a Gaussian pulse with a peak power of 800 W and a full width at half maximum(FWHM)of 20 fs at wavelength of 3.3μm.When the fiber is pumped by the pulse with the peak power of 2000 W,the FWHM of 80 fs at the wavelength of 4.0μm in the in the anomalous dispersion region,the modulation instability is obviously suppressed,and the high-coher-ence supercontinuum spectrum spanning from 1.1μm to 8.99μm is observed.A part of the pulse energy is transferred to the anomalous dispersion region when pumped at the wavelength of 2.8μm in the normal dis-persion region and a broadband high-coherence supercontinuum spectrum extending from 0.8μm to 9.8μm is generated in the 10 mm proposed fiber.This paper introduces elliptical air holes in the Al_(0.24)Ga_(0.76)As photonic crystal fiber,which enhances flexibility for tailoring the performance of supercontinuum,ultimately achieving the broadest supercontinuum spectrum with the shortest fiber length to date.展开更多
Noise interference critically impairs the stability and data accuracy of sensing systems.However,current suppression strategies fail to concurrently mitigate intrinsic system noise and extrinsic environmental noise.Th...Noise interference critically impairs the stability and data accuracy of sensing systems.However,current suppression strategies fail to concurrently mitigate intrinsic system noise and extrinsic environmental noise.This study introduces a composite denoising approach to address this challenge.This method is based on the ameliorated ellipse fitting algorithm(AEFA)and adaptive successive variational mode decomposition(ASVMD).This algorithm employs AEFA to eliminate system noise tightly coupled with direct-current and alternating-current components in the interference signal,thereby obtaining a phase signal containing only environmental noise.The ASVMD technique adaptively extracts environmental noise components predominantly present in the phase signal.To achieve optimal decomposition results automatically,the permutation entropy criterion is employed to refine decomposition parameters.The correlation coefficient is utilized to differentiate effective components from noise components in the decomposition results.Experimental results indicate that the combined AEFA and ASVMD algorithm effectively suppresses both system and environmental noises.When applied to 50 Hz vibration signal processing,the proposed approach achieves a noise reduction of 17.81 dB and a phase resolution of 35.14μrad/√Hz.Given the excellent performance of the noise suppression,the proposed approach holds great application potential in high-performance interferometric sensing systems.展开更多
Let κ be non-negative integer. The unoriented bordism classes, which can be represented as [RP（ξ^κ）] where ξ^κ is a k-plane bundle, form an ideal of the unoriented bordism ring MO.. A group of generators of thi...Let κ be non-negative integer. The unoriented bordism classes, which can be represented as [RP（ξ^κ）] where ξ^κ is a k-plane bundle, form an ideal of the unoriented bordism ring MO.. A group of generators of this ideal expressed by a base of MO. and a necessary and sufficient condition for a bordism class to belong to this ideal are given.展开更多
We discuss recent progress in using machine-learning(ML)-enabled inverse design techniques applied to photonic devices and components.Specifically,we highlight the design of optical sources,including fiber and semicon...We discuss recent progress in using machine-learning(ML)-enabled inverse design techniques applied to photonic devices and components.Specifically,we highlight the design of optical sources,including fiber and semiconductor lasers,as well as Raman and semiconductor optical amplifiers.Although inverse design approaches for optical detectors remain relatively underexplored,we examine optical layers,particularly metamaterial absorbers,as promising candidates for high-performance optical detection.In addition,we underscore advancements in inverse designing passive optical components,including beam splitters,gratings,and optical fibers.These optical blocks are fundamental in developing next-generation standalone optical communication systems and optical sensing networks,including integrated sensing and communication technologies.While categorizing various reported deep learning architectures across five paradigms,we offer a paradigm-based perspective that reveals how different ML techniques function within modern inverse design methods and enable fast,data-driven solutions that significantly reduce design time and computational demands compared with traditional optimization methods.展开更多
PKU:The super fibers combine strength and toughness In impact protection applications such as ballistic armor,vehicle shielding,and aerospace,the dynamic strength and dynamic toughness of fiber materials are critical ...PKU:The super fibers combine strength and toughness In impact protection applications such as ballistic armor,vehicle shielding,and aerospace,the dynamic strength and dynamic toughness of fiber materials are critical performance indicators determining protective efficacy.However,widely used polymeric fibers still face significant challenges preventing full utilization of the material’s intrinsic strength and toughness.展开更多
Oil palm fiber is a natural fiber derived from agricultural biomass and has gained significant attention as an alternative reinforcement material in composite materials due to its abundance,renewability,and environmen...Oil palm fiber is a natural fiber derived from agricultural biomass and has gained significant attention as an alternative reinforcement material in composite materials due to its abundance,renewability,and environmental benefits.This review explores the various enhancement techniques applied to oil palm fiber to improve its properties for composite material development.Key areas of focus include chemical treatments,physical modifications,and hybridization with other fibers to improve fiber-matrix bonding,mechanical strength,and thermal stability.Integration of nanomaterials and bio-based resins to enhance the performance and sustainability of oil palm fiber composites is also discussed.Applications in industries such as automotive,construction,packaging,and consumer goods highlighted the potential for these composites to replace traditional,non-renewable materials.Challenges such as fiber variability,production scalability,and market adoption were examined,along with future directions in advancing oil palm fiber-based composites.展开更多
Background Heat shock proteins(HSPs)are key molecular chaperones that help maintain protein homeostasis by stabilizing or removing damaged proteins during cellular stress.Aging weakens these stress–response systems,d...Background Heat shock proteins(HSPs)are key molecular chaperones that help maintain protein homeostasis by stabilizing or removing damaged proteins during cellular stress.Aging weakens these stress–response systems,disrupting proteostasis and increasing vulnerability to sarcopenia.High-intensity training(HIT)can counteract these declines by activating protective pathways such as the HSP response.HSPs are highly responsive to stress,examining their regulation during aging is important,as altered HSP activity is linked to the progressive loss of muscle mass.Methods This study investigated the abundance and phosphorylation of HSPs in skeletal muscle from healthy,active young and older adults(n=7 per group),assessed at baseline and again in the older group following 12 weeks of HIT.Using calibrated Western blotting on both whole-muscle homogenates and pooled single muscle fibres,we quantified HSP content and phosphorylation to determine how aging and exercise influence stress–responsive protein regulation at both the tissue and cellular levels.Results In whole muscle homogenates,HSPs(HSP72,HSP27,andαB-crystallin)did not differ between young and older adults,while higher phosphorylation of small HSPs(sHSPs):phospho-HSP27 at Serine15(pHSP27 Ser15)and phospho-αB-crystallin at Serine59(pαB-crystallin Ser59)(∼1.8-fold and∼2.9-fold,respectively)were found in muscle from older adults,indicating higher cellular stress associated with aging.A 12-week HIT intervention in older adults reduced homogenate pHSP27 Ser15 and pαB-crystallin Ser59 abundances to similar levels found in young adults.Total HSPs typically displayed a distinct fiber-type profile in both age groups,with more in type I compared to type II fibers,distinguished by the presence of myosin heavy chain I(MHCI)or MHCII.Phosphorylation at pHSP27 Ser15 and pαB-crystallin Ser59 was not different between type I and type II fibers.The HIT in older adults decreased total and phosphorylated sHSPs in both type I and type II fibers but increased HSP72 in type I fibers.Conclusion HIT has the potential to mitigate age-related cellular stress and modulate protein expression patterns in aging skeletal muscle and,perhaps,has the potential to delay age-related muscle decline,thereby improving muscle health in older adults.展开更多
Engineered Cementitious Composites(ECC)represent an advanced class of fiber-reinforced cementbased materials developed over the past three decades,characterized by remarkable tensile strain-hardening and multiple-crac...Engineered Cementitious Composites(ECC)represent an advanced class of fiber-reinforced cementbased materials developed over the past three decades,characterized by remarkable tensile strain-hardening and multiple-cracking behavior.By incorporating hybrid fibers,Hybrid Fiber engineered cementitious composites(HFECC)can be tailored tomeet specific engineering demands in terms of strength,deformation,dynamicmechanical performance,and cost-effectiveness.This paper provides a comprehensive review of the critical fiber volume theory,experimental investigations into quasi-static and dynamic mechanical properties,and the structural performance of HFECC.Furthermore,current research gaps and future directions for the development and application of HFECC are discussed,aiming to facilitate its broader engineering adoption.In addition,this review emphasizes the micromechanical design principles governing fiber–matrix interactions,highlighting how hybridization strategies optimize the synergy between different fiber types to balance ductility and strength.The practical implications of HFECC in seismicresistant,impact-resistant,and repair applications are also analyzed.Through an integrated discussion of theoretical and experimental findings,this study seeks to provide a systematic understanding of HFECC behavior and promote its advancement toward sustainable and high-performance infrastructure applications.展开更多
The two distinct types of composite materials(5%to 10%)were developed using recycled polyvinyl alcohol fiber(RPA),silicon nitride fiber(SN),and reduced carbon nanoparticles(RCN).Enhanced microstructural properties and...The two distinct types of composite materials(5%to 10%)were developed using recycled polyvinyl alcohol fiber(RPA),silicon nitride fiber(SN),and reduced carbon nanoparticles(RCN).Enhanced microstructural properties and mechanical strength were attained through the application of the 3-glycidoxypropyltrimethoxysilane coupling method.The combination of the resin-like properties of RPA-SN fiber resulted in the formation of robust outer strength and a high bonding structure.RPA-RCN composite materials with a weight percentage of 10%exhibited a tensile strength of 42 MPa.In contrast,RPA-SN-RCN composite materials containing 5%to 10%demonstrated enhanced tensile,bending,and hardness properties.Pyramid structures,solid structures,and crystal phases were formed using RCN particles.The resin and silane properties on hardness were gradually 14%increasing the outside region,whereas RPA-SN-RCN(10 wt%)on average hardness were attained at 86(Shore-D).The microstructures on RPA-RCN(5%to 10%)samples were observed solid structure,twin boundary’s structure and lattice structure.The tensile strength of RPA-SN-RCN(10%)was 67.3MPa,whereas the impact strength of RPA-RCN(10 wt%)was 53 J/mm2.The scanning electron microscopies(SEM)were used to investigate the microstructure of the RPA-SN-RCN(5%)and RPA-SN-RCN(10%)composite materials,respectively.展开更多
The rapid evolution of the autonomous driving industry has led to a surge in electronic units and applications,resulting in increased in-vehicle data traffic and higher demands for communication efficiency and securit...The rapid evolution of the autonomous driving industry has led to a surge in electronic units and applications,resulting in increased in-vehicle data traffic and higher demands for communication efficiency and security.Meanwhile,safe driving necessitates further development of in-vehicle thermal management systems,as traditional point-type sensors face deployment challenges due to their limited monitoring range.All-glass multimode fibers(AG-MMFs)emerge as an ideal solution for sensing and transmission.An integrated sensing and communication(ISAC)system based on AG-MMFs has been proposed and experimentally validated for stable and efficient operation across a broad temperature range from-18°C to 122°C,while maintaining strong tolerance to typical vehicle vibrations and connector misalignments.Utilizing a single commercial OM4 fiber,we achieve error-free PAM-4 transmission up to 100 Gb∕s with the aid of forward error correction and precise real-time temperature monitoring over 100 m at the same time.Furthermore,by adopting a looped link structure and a neural network-based denoising algorithm,temperature measuring maintains an average uncertainty and a spatial resolution of 0.1°C and 0.5 m,respectively,even under extreme conditions.Exhibiting such outstanding performance in both transmission and sensing,the ISAC architecture successfully addresses the growing demands for high-capacity in-vehicle networks and distributed thermal monitoring of critical components,while paving the theoretical foundation for“fiber to vehicle.”展开更多
As the global textile industry has accelerated its transition to a circular economy,iterative innovation in regenerated cellulose fibers has become a key industry focus.With viscose fiber having been industrialized fo...As the global textile industry has accelerated its transition to a circular economy,iterative innovation in regenerated cellulose fibers has become a key industry focus.With viscose fiber having been industrialized for over a century and lyocell fiber gaining market recognition because of its environmentally friendly process,which is the next regenerated cellulose fiber.Herein,ionic liquids with low vapor pressure,nonflammability,relatively simple recovery,and high dissolution efficiency were used to fabricate regenerated cellulose fibers.The viscose and lyocell properties of the fibers were systematically compared,including microscopic morphology,dyeing behavior,fibrillation resistance,mechanical properties,yarn-forming capacity,and fabric performance.The ionic liquid(IL)fiber exhibited a smooth surface and circular cross-section,with the highest tensile strength,moderate dyeing and fibrillation properties,and similar spinning and weaving performance.This work can provide a reference for the commercial application of regenerated cellulose fibers fabricated from ionic liquid.展开更多
基金Project Supported by NSFC (10371029),HNSF (103144)and SRF for ROCS, SEM
文摘Let RP（k） denote the k-dimensional real projective space. This article determines which cobordism classes are represented by the total space of a fibering with prescribed base space RP（3）× RP（1）, RP（2） × RP（1）, RP（2）× RP（1）× RP（1） or RP（3）× RP（2）.
基金financially supported by the National Natural Science Foundation of China(Nos.52303298 and 52233002)。
文摘UHMWPE fibers exhibit impressive modulus and strength,but they have not reached their theoretical limits.Researchers focus on molecular weight,orientation,and crystallinity of UHMWPE,yet their contributions to mechanical properties are unclear.Molecular dynamics simulations are valuable but often limited by computational constraints.Our aim is to simulate higher molecular weights to better represent real UHMWPE fibers.We used Packmol and Polyply methodologies to construct PE systems,with Polyply reproducing more reasonable properties of UHMWPE fibers.Additionally,tensile simulations showed that orientation and crystallinity greatly impact Young's modulus more than molecular weight.Energy decomposition indicated that higher molecular weights lead to covalent bonds that can withstand more energy during stretching,thus increasing breaking strength.Combining simulations with machine learning,we found that orientation has the most significant impact on Young's modulus,contributing 60%,and molecular weight plays the most crucial role in determining the breaking strength,accounting for 65%.This study provides a theoretical basis and guidelines for enhancing UHMWPE's modulus and strength.
基金Supported by the National Natural Science Foundation of China(22468035,22468036,22368038,22308048)the Natural Science Foundation of Inner Mongolia(2024QN02018,2025MS02030)+2 种基金First-class Discipline Research Special Project of Inner Mongolia(YLXKZX-NGD-045)Inner Mongolia Autonomous Region Postgraduate Research Innovation Project(KC2024047B)Research Foundation for Introducing High-level Talents in Inner Mongolia Autonomous Region。
文摘The global energy landscape is undergoing a profound transformation,with wind energy,especially wind power,gaining increasing prominence due to its clean,renewable nature.However,as the installed capacity of wind power continues to expand,the disposal of waste wind turbine blades(WWTB)has emerged as a significant challenge.These blades are predominantly composed of epoxy resin(EP)polymers,carbon fibers(CFs),and glass fibers(GFs).Improper disposal not only exacerbates environmental concerns but also leads to the loss of valuable resources,particularly carbon-based materials.Pyrolysis technology,a versatile and environmentally sustainable method for resource recovery,has garnered considerable attention in the context of WWTB disposal.This work presents a comprehensive review of the pyrolytic recycling of WWTB,focusing on the principles and classifications of pyrolysis technology,key factors influencing the pyrolysis process,as well as the pyrolysis methods,equipment,products,and their applications.Through an in-depth analysis of the current research on the pyrolytic recycling of WWTB,this review identifies critical unresolved issues in the field and provides a forward-looking perspective on emerging research trends.
文摘We designed and investigated a passive synchronized mode-locked fiber laser.The device utilizes a dual-cavity structure driven by the nonlinear polarization rotation(NPR)mechanism.Stable mode-locking is attained by synergistically controlling gain,polarization state,and optical path length in two symmetric sub-cavities.Experiments proved that repetition rate of the sub-cavities can be adjusted via the time delay line(TDL)to achieve synchronized mode-locking.The system stably generates multi-wavelength pulses at a single repetition frequency,evidenced by multiple spectral peaks and equidistant pulse sequences.These findings facilitate the development of high-performance multi-wavelength ultrashort pulse sources,crucial for optical communications,spectral analysis,and remote sensing.
文摘We report a method for increasing the mechanical strength of carbon nanotube(CNT)fibers while enabling the uniform adhesion of cerium oxide(CeO_(2))abrasive particles to them using polyethyleneimine(PEI).Results show that 5%of PEI increases the tensile strength of CNT fibers by approximately 175%.CeO_(2) particles were uniformly deposited on the reinforced CNT fibers by electrophoretic deposition.A flexible polishing tool was fabricated by weaving the CeO_(2)-CNT fibers into a non-woven fabric substrate.When used to polish potassium dihydrogen phosphate crystals,the tool reduced the surface roughness from 200 to 7.6 nm within 10 min.This approach has potential use for the development of new precision processing tools.
文摘To address the challenges of complex metallic film coating processes and low integration in single-parameter detection for existing photonic crystal fiber surface plasmon resonance(PCF-SPR)sensors,a dual-parameter sensor based on gold nanowire-integrated bias-core PCF-SPR is proposed.Unlike conventional in-hole coatings or metallic film structures,the gold nanowires are directly attached to the fiber cladding via chemical vapor deposition(CVD),eliminating uneven coating issues and significantly simplifying fabrica-tion.By optimizing the asymmetric bias-core fiber structure and leveraging the strong localized field en-hancement of gold nanowires,the sensor achieves high-sensitivity synchronous detection of temperature(25−60℃)and refractive index(1.31−1.40)in dual-polarization modes.The simulation results demonstrate that the x-polarization mode can achieve 1.31−1.40 refractive index detection with maximum wavelength sensitivity and amplitude sensitivity of 14800 nm/RIU and−1724.25 RIU^(−1),and maximum refractive index resolution of 6.75×10^(−6)RIU.The y-polarization mode achieves refractive index detection range of 1.34−1.40,and the maximum wavelength sensitivity and amplitude sensitivity are 28400 nm/RIU and−1298.93 RIU^(−1),and the maximum refractive index resolution is 3.52×10^(−6)RIU.For temperature sensing,the sensor exhibits a wavelength sensitivity of 7.8 nm/℃and a high resolution of 1.38×10^(−6)℃over the range of 25−60℃.This design synergizes gold nanowires and the bias-core architecture to simplify fabrication while enabling multi-parameter detection.The proposed sensor offers new insights for integrated applications in biochemical mon-itoring,environmental sensing,and related fields.
基金National Natural Science Foundation of China(52172108)National Key R&D Program of China(2022YFB3707700)Strategic Priority Research Program of the Chinese Academy of Sciences(XDC0144005)。
文摘Silicon carbide fibers are considered ideal reinforcing materials for ceramic matrix composites due to their excellent mechanical properties and high-temperature performance.Different types of fibers necessitate individual investigation due to variations in their composition and fabrication processes.This study presents a comprehensive investigation into evolution of the mechanical properties,surface microstructure,and composition of Shicolon-Ⅱ fibers subjected to argon heat treatment at temperatures ranging from 1300℃to 1700℃.The Shicolon-Ⅱ fibers are composed of small-sized β-SiC grains,SiC_(x)O_(y) amorphous phase,and a minor amount of graphite microcrystals.Following treatment in an argon atmosphere at 1300℃,the fibers maintain a monofilament tensile strength of 3.620 GPa,corresponding to a retention of 98.32%.This strength diminishes to 2.875 GPa,equating to a retention of 78.08%,after treatment at 1500℃.The reduction in mechanical properties of the fibers can be ascribed to the decomposition of the amorphous phase and the growth of β-SiC grains.Furthermore,creep resistance is an essential factor influencing the long-term performance of composite materials.After treatment at temperatures above 1400℃,the high-temperature creep resistance of the fibers is significantly enhanced due to growth of β-SiC grains.This study offers valuable theoretical insights into high-temperature applications of second-generation fibers,contributing to an enhanced understanding of their performance under extreme conditions.
文摘An alternative elliptical and circle air-hole-assisted Al_(0.24)Ga_(0.76)As photonic crystal fiber(PCF)was proposed for generating broadband high-coherence mid-infrared supercontinuum,and the dispersion,effect-ive mode area and nonlinear coefficient were investigated by using finite element method(FEM),the evolu-tion of optical pulses propagating along the fiber was simulated,and the supercontinuum and the coherence were analyzed and evaluated under different pumping conditions.The results show that a supercontinuum spectrum with a spectral width of 4.852μm can be obtained in the proposed fiber with d_(1)/Λof 0.125,d_(2)/Λof 0.583 and the zero-dispersion wavelength of 3.228μm by pumping with a Gaussian pulse with a peak power of 800 W and a full width at half maximum(FWHM)of 20 fs at wavelength of 3.3μm.When the fiber is pumped by the pulse with the peak power of 2000 W,the FWHM of 80 fs at the wavelength of 4.0μm in the in the anomalous dispersion region,the modulation instability is obviously suppressed,and the high-coher-ence supercontinuum spectrum spanning from 1.1μm to 8.99μm is observed.A part of the pulse energy is transferred to the anomalous dispersion region when pumped at the wavelength of 2.8μm in the normal dis-persion region and a broadband high-coherence supercontinuum spectrum extending from 0.8μm to 9.8μm is generated in the 10 mm proposed fiber.This paper introduces elliptical air holes in the Al_(0.24)Ga_(0.76)As photonic crystal fiber,which enhances flexibility for tailoring the performance of supercontinuum,ultimately achieving the broadest supercontinuum spectrum with the shortest fiber length to date.
文摘Noise interference critically impairs the stability and data accuracy of sensing systems.However,current suppression strategies fail to concurrently mitigate intrinsic system noise and extrinsic environmental noise.This study introduces a composite denoising approach to address this challenge.This method is based on the ameliorated ellipse fitting algorithm(AEFA)and adaptive successive variational mode decomposition(ASVMD).This algorithm employs AEFA to eliminate system noise tightly coupled with direct-current and alternating-current components in the interference signal,thereby obtaining a phase signal containing only environmental noise.The ASVMD technique adaptively extracts environmental noise components predominantly present in the phase signal.To achieve optimal decomposition results automatically,the permutation entropy criterion is employed to refine decomposition parameters.The correlation coefficient is utilized to differentiate effective components from noise components in the decomposition results.Experimental results indicate that the combined AEFA and ASVMD algorithm effectively suppresses both system and environmental noises.When applied to 50 Hz vibration signal processing,the proposed approach achieves a noise reduction of 17.81 dB and a phase resolution of 35.14μrad/√Hz.Given the excellent performance of the noise suppression,the proposed approach holds great application potential in high-performance interferometric sensing systems.
基金This work is supported by HNSF(Grant No:103144) NNSF of China(10371029)
文摘Let κ be non-negative integer. The unoriented bordism classes, which can be represented as [RP（ξ^κ）] where ξ^κ is a k-plane bundle, form an ideal of the unoriented bordism ring MO.. A group of generators of this ideal expressed by a base of MO. and a necessary and sufficient condition for a bordism class to belong to this ideal are given.
基金the School of Engineering and Built Environment at Anglia Ruskin University,UK,for the supportthe support of IRC-CSS and the Electrical Engineering Department,KFUPM,Saudi Arabia。
文摘We discuss recent progress in using machine-learning(ML)-enabled inverse design techniques applied to photonic devices and components.Specifically,we highlight the design of optical sources,including fiber and semiconductor lasers,as well as Raman and semiconductor optical amplifiers.Although inverse design approaches for optical detectors remain relatively underexplored,we examine optical layers,particularly metamaterial absorbers,as promising candidates for high-performance optical detection.In addition,we underscore advancements in inverse designing passive optical components,including beam splitters,gratings,and optical fibers.These optical blocks are fundamental in developing next-generation standalone optical communication systems and optical sensing networks,including integrated sensing and communication technologies.While categorizing various reported deep learning architectures across five paradigms,we offer a paradigm-based perspective that reveals how different ML techniques function within modern inverse design methods and enable fast,data-driven solutions that significantly reduce design time and computational demands compared with traditional optimization methods.
文摘PKU:The super fibers combine strength and toughness In impact protection applications such as ballistic armor,vehicle shielding,and aerospace,the dynamic strength and dynamic toughness of fiber materials are critical performance indicators determining protective efficacy.However,widely used polymeric fibers still face significant challenges preventing full utilization of the material’s intrinsic strength and toughness.
文摘Oil palm fiber is a natural fiber derived from agricultural biomass and has gained significant attention as an alternative reinforcement material in composite materials due to its abundance,renewability,and environmental benefits.This review explores the various enhancement techniques applied to oil palm fiber to improve its properties for composite material development.Key areas of focus include chemical treatments,physical modifications,and hybridization with other fibers to improve fiber-matrix bonding,mechanical strength,and thermal stability.Integration of nanomaterials and bio-based resins to enhance the performance and sustainability of oil palm fiber composites is also discussed.Applications in industries such as automotive,construction,packaging,and consumer goods highlighted the potential for these composites to replace traditional,non-renewable materials.Challenges such as fiber variability,production scalability,and market adoption were examined,along with future directions in advancing oil palm fiber-based composites.
文摘Background Heat shock proteins(HSPs)are key molecular chaperones that help maintain protein homeostasis by stabilizing or removing damaged proteins during cellular stress.Aging weakens these stress–response systems,disrupting proteostasis and increasing vulnerability to sarcopenia.High-intensity training(HIT)can counteract these declines by activating protective pathways such as the HSP response.HSPs are highly responsive to stress,examining their regulation during aging is important,as altered HSP activity is linked to the progressive loss of muscle mass.Methods This study investigated the abundance and phosphorylation of HSPs in skeletal muscle from healthy,active young and older adults(n=7 per group),assessed at baseline and again in the older group following 12 weeks of HIT.Using calibrated Western blotting on both whole-muscle homogenates and pooled single muscle fibres,we quantified HSP content and phosphorylation to determine how aging and exercise influence stress–responsive protein regulation at both the tissue and cellular levels.Results In whole muscle homogenates,HSPs(HSP72,HSP27,andαB-crystallin)did not differ between young and older adults,while higher phosphorylation of small HSPs(sHSPs):phospho-HSP27 at Serine15(pHSP27 Ser15)and phospho-αB-crystallin at Serine59(pαB-crystallin Ser59)(∼1.8-fold and∼2.9-fold,respectively)were found in muscle from older adults,indicating higher cellular stress associated with aging.A 12-week HIT intervention in older adults reduced homogenate pHSP27 Ser15 and pαB-crystallin Ser59 abundances to similar levels found in young adults.Total HSPs typically displayed a distinct fiber-type profile in both age groups,with more in type I compared to type II fibers,distinguished by the presence of myosin heavy chain I(MHCI)or MHCII.Phosphorylation at pHSP27 Ser15 and pαB-crystallin Ser59 was not different between type I and type II fibers.The HIT in older adults decreased total and phosphorylated sHSPs in both type I and type II fibers but increased HSP72 in type I fibers.Conclusion HIT has the potential to mitigate age-related cellular stress and modulate protein expression patterns in aging skeletal muscle and,perhaps,has the potential to delay age-related muscle decline,thereby improving muscle health in older adults.
基金financed by Hainan provincial Science and Tecnology Special Fund(No.ZDY F2025GXJS196)Guangxi Transportation Science and Technology Achievement Promotion Project(GXJT-YFZX-2024-01-01):Intelligent Detection and Data Application R&D Center for Guangxi Transportation Industry.
文摘Engineered Cementitious Composites(ECC)represent an advanced class of fiber-reinforced cementbased materials developed over the past three decades,characterized by remarkable tensile strain-hardening and multiple-cracking behavior.By incorporating hybrid fibers,Hybrid Fiber engineered cementitious composites(HFECC)can be tailored tomeet specific engineering demands in terms of strength,deformation,dynamicmechanical performance,and cost-effectiveness.This paper provides a comprehensive review of the critical fiber volume theory,experimental investigations into quasi-static and dynamic mechanical properties,and the structural performance of HFECC.Furthermore,current research gaps and future directions for the development and application of HFECC are discussed,aiming to facilitate its broader engineering adoption.In addition,this review emphasizes the micromechanical design principles governing fiber–matrix interactions,highlighting how hybridization strategies optimize the synergy between different fiber types to balance ductility and strength.The practical implications of HFECC in seismicresistant,impact-resistant,and repair applications are also analyzed.Through an integrated discussion of theoretical and experimental findings,this study seeks to provide a systematic understanding of HFECC behavior and promote its advancement toward sustainable and high-performance infrastructure applications.
基金the support provided by the Department of Mechanical Engineering,AAA college of Engineering and Technology,Sivakasi,Tamilnadu,India for facilitating the experimental and characterization facilities required to carry out this research work.
文摘The two distinct types of composite materials(5%to 10%)were developed using recycled polyvinyl alcohol fiber(RPA),silicon nitride fiber(SN),and reduced carbon nanoparticles(RCN).Enhanced microstructural properties and mechanical strength were attained through the application of the 3-glycidoxypropyltrimethoxysilane coupling method.The combination of the resin-like properties of RPA-SN fiber resulted in the formation of robust outer strength and a high bonding structure.RPA-RCN composite materials with a weight percentage of 10%exhibited a tensile strength of 42 MPa.In contrast,RPA-SN-RCN composite materials containing 5%to 10%demonstrated enhanced tensile,bending,and hardness properties.Pyramid structures,solid structures,and crystal phases were formed using RCN particles.The resin and silane properties on hardness were gradually 14%increasing the outside region,whereas RPA-SN-RCN(10 wt%)on average hardness were attained at 86(Shore-D).The microstructures on RPA-RCN(5%to 10%)samples were observed solid structure,twin boundary’s structure and lattice structure.The tensile strength of RPA-SN-RCN(10%)was 67.3MPa,whereas the impact strength of RPA-RCN(10 wt%)was 53 J/mm2.The scanning electron microscopies(SEM)were used to investigate the microstructure of the RPA-SN-RCN(5%)and RPA-SN-RCN(10%)composite materials,respectively.
基金supported by the National Key R&D Program of China(Grant No.2023YFB2906303)the National Natural Science Foundation of China(Grant No.62225110)+1 种基金the JD Project of Hubei Province(Grant No.2023BAA013)the Innovation Fund of WNLO。
文摘The rapid evolution of the autonomous driving industry has led to a surge in electronic units and applications,resulting in increased in-vehicle data traffic and higher demands for communication efficiency and security.Meanwhile,safe driving necessitates further development of in-vehicle thermal management systems,as traditional point-type sensors face deployment challenges due to their limited monitoring range.All-glass multimode fibers(AG-MMFs)emerge as an ideal solution for sensing and transmission.An integrated sensing and communication(ISAC)system based on AG-MMFs has been proposed and experimentally validated for stable and efficient operation across a broad temperature range from-18°C to 122°C,while maintaining strong tolerance to typical vehicle vibrations and connector misalignments.Utilizing a single commercial OM4 fiber,we achieve error-free PAM-4 transmission up to 100 Gb∕s with the aid of forward error correction and precise real-time temperature monitoring over 100 m at the same time.Furthermore,by adopting a looped link structure and a neural network-based denoising algorithm,temperature measuring maintains an average uncertainty and a spatial resolution of 0.1°C and 0.5 m,respectively,even under extreme conditions.Exhibiting such outstanding performance in both transmission and sensing,the ISAC architecture successfully addresses the growing demands for high-capacity in-vehicle networks and distributed thermal monitoring of critical components,while paving the theoretical foundation for“fiber to vehicle.”
基金financially supported by the National Natural Science Foundation of China(Nos.22005226 and 52203124)Center for Carbon Neutral Chemistry,Institute of Chemistry,Chinese Academy of Sciences(No.CCNC-202402)+1 种基金the Basic and Advanced Research Project from Wuhan Science and Technology Bureau(No.2022013988065201)Hubei Integrative Technology and Innovation Center for Advanced Fiberous Materials,project(No.XC2024G3013)。
文摘As the global textile industry has accelerated its transition to a circular economy,iterative innovation in regenerated cellulose fibers has become a key industry focus.With viscose fiber having been industrialized for over a century and lyocell fiber gaining market recognition because of its environmentally friendly process,which is the next regenerated cellulose fiber.Herein,ionic liquids with low vapor pressure,nonflammability,relatively simple recovery,and high dissolution efficiency were used to fabricate regenerated cellulose fibers.The viscose and lyocell properties of the fibers were systematically compared,including microscopic morphology,dyeing behavior,fibrillation resistance,mechanical properties,yarn-forming capacity,and fabric performance.The ionic liquid(IL)fiber exhibited a smooth surface and circular cross-section,with the highest tensile strength,moderate dyeing and fibrillation properties,and similar spinning and weaving performance.This work can provide a reference for the commercial application of regenerated cellulose fibers fabricated from ionic liquid.
