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
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
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
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
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
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
The remodeling of axonal connections following injury is an important feature driving functional recovery.The reticulospinal tract is an interesting descending motor tract that contains both excitatory and inhibitory ...The remodeling of axonal connections following injury is an important feature driving functional recovery.The reticulospinal tract is an interesting descending motor tract that contains both excitatory and inhibitory fibers.While the reticulospinal tract has been shown to be particularly prone to axonal growth and plasticity following injuries of the spinal cord,the differential capacities of excitatory and inhibitory fibers for plasticity remain unclear.As adaptive axonal plasticity involves a sophisticated interplay between excitatory and inhibitory input,we investigated in this study the plastic potential of glutamatergic(vGlut2)and GABAergic(vGat)fibers originating from the gigantocellular nucleus and the lateral paragigantocellular nucleus,two nuclei important for locomotor function.Using a combination of viral tracing,chemogenetic silencing,and AI-based kinematic analysis,we investigated plasticity and its impact on functional recovery within the first 3 weeks following injury,a period prone to neuronal remodeling.We demonstrate that,in this time frame,while vGlut2-positive fibers within the gigantocellular and lateral paragigantocellular nuclei rewire significantly following cervical spinal cord injury,vGat-positive fibers are rather unresponsive to injury.We also show that the acute silencing of excitatory axonal fibers which rewire in response to lesions of the spinal cord triggers a worsening of the functional recovery.Using kinematic analysis,we also pinpoint the locomotion features associated with the gigantocellular nucleus or lateral paragigantocellular nucleus during functional recovery.Overall,our study increases the understanding of the role of the gigantocellular and lateral paragigantocellular nuclei during functional recovery following spinal cord injury.展开更多
We investigate theoretically and experimentally the chaotic dynamics of visible-wavelength all-fiber ring laser.The100-m 630 HP fibers are used to ensure high non-linearity.A 4-m Pr^(3+)/Yb^(3+)-co-doped ZBLAN fiber p...We investigate theoretically and experimentally the chaotic dynamics of visible-wavelength all-fiber ring laser.The100-m 630 HP fibers are used to ensure high non-linearity.A 4-m Pr^(3+)/Yb^(3+)-co-doped ZBLAN fiber provides the gain.The chaotic laser was pumped by the laser diodes with the maximum power of 150 mW at the wavelength of 850 nm.The peak fluorescence spectrum of Pr^(3+)/Yb^(3+)-co-doped ZBLAN fiber at the wavelength of 635 nm shows that the visiblewavelength fiber laser can be achieved by synergistic energy transfer between Pr~(3+)and Yb^(3+)ions.The chaotic fiber laser is generated by adjusting the pump power,polarization controller and the auto-correlation,permutation entropy,skewness,and kurtosis were used to analyze the characteristics of chaotic laser.The noise-like time series and delta-like auto-correlation curve indicate the chaotic output.The complexity and randomness of time series are analyzed by the permutation entropy,skewness,and kurtosis.The result shows that chaotic dynamics is stable when the pump power exceeds a certain value.The visible chaotic all-fiber laser has high stability and can be applied for real-time monitoring and sensing.We believe that this approach may also be feasible for other materials for emission in the visible range.展开更多
As the speeds of trains increase,higher demands are placed on brake materials.In order to overcome the thermal degradation phenomenon of brake pads during high-speed braking,we prepared copper fiber reinforced alkali-...As the speeds of trains increase,higher demands are placed on brake materials.In order to overcome the thermal degradation phenomenon of brake pads during high-speed braking,we prepared copper fiber reinforced alkali-activated slag composite(AASC)friction materials by hot-pressing method,using slag as matrix,Na_(2)SiO_(3)·9H_(2)O as alkali excitant,copper fiber as reinforcement,and graphite as friction modifier.The results show that the AASC prepared by hot-pressing method has undergone alkali-activated reaction and has geopolymer amorphous characteristics as the conventional cast molding AASC by XRD analysis.The addition of copper fibers can improve the mechanical strength and toughness of the composites substantially,and the AASC has the highest flexural strength,compressive strength and impact toughness when the volume fraction of copper fibers reaches 25 vol%.Toughening mechanisms such as drawing,bridging and crack deflection of copper fibers in composites were analyzed by SEM morphology.Addition of appropriate amount of graphite to AASC can effectively reduce the wear rate and improve the stability of the material friction coefficient.The coefficient of friction also remains stable in the high-speed friction experiments without thermal degradation.Therefore,copper fiber reinforced AASC friction materials prepared by hot-pressing method has good mechanical and friction properties.展开更多
To develop a suitable production process for fiber reinforced investment casting shell mold,three methods were studied:the traditional method(M_(1)),the method of adding fiber into silica sol with mechanical stirring ...To develop a suitable production process for fiber reinforced investment casting shell mold,three methods were studied:the traditional method(M_(1)),the method of adding fiber into silica sol with mechanical stirring and ultrasonic agitation(M_(2)),and the method of adding fiber into slurry with mechanical stirring and ultrasonic agitation for durations of 3,15,30,and 45 min(M_(3)).The bending strength,high-temperature self-load deformation,and thermal conductivity of the shell molds were investigated.The results reveal that the enhancement of fiber dispersion through ultrasonic agitation improves the comprehensive performance of the shell molds.The maximum green bending strength of the shell mold by M_(2) reaches 3.29 MPa,which is 29% higher than that of the shell mold prepared by M_(1).Moreover,the high-temperature self-load deformation of the shell mold is reduced from 0.62% to 0.44%.In addition,simultaneous ultrasonic agitation and mechanical stirring effectively shorten the slurry preparation time while maintaining comparable levels of fiber dispersion.With the process M_(3)-45 min,the fillers are uniformly dispersed in the slurry,and the fired bending strength and the high-temperature self-load deformation reach 6.25 MPa and 0.41%,respectively.Therefore,the proposed ultrasonic agitation route is promising for the fabrication of fiber-reinforced shell molds with excellent fibers dispersion.展开更多
This review draws attention to the innovative use of arrowroot(Maranta arundinacea)fiber as a unique and underutilized biomass source for nanocrystalline cellulose(NCC)-based nanocomposites,presenting a noteworthy alt...This review draws attention to the innovative use of arrowroot(Maranta arundinacea)fiber as a unique and underutilized biomass source for nanocrystalline cellulose(NCC)-based nanocomposites,presenting a noteworthy alternative to extensively researched materials like wood pulp,bacterial cellulose,and chemically modified NCCs.In contrast to traditional sources,arrowroot possesses a naturally elevated cellulose and diminished lignin content,facilitating more effective NCC extraction requiring reduced chemical input and enabling environmentally friendly processing techniques.The review evaluates the performance of arrowroot-derived nanocomposites against systems documented in the literature,including NCC-based shape memory composites and nanoparticle-reinforced films,demonstrating enhanced tensile strength,improved moisture barrier properties,and thermal stability,as well as potential piezoelectric response.This study recognizes arrowroot as a viable option in the biomass-based nanocellulose sector,providing ecological and functional benefits while tackling significant issues such as process scalability and feedstock variability,thereby offering important insights for the advancement of sustainable materials.展开更多
Natural colored cotton(NCC)offers a sustainable,dye-free,and eco-friendly alternative for producing colored textiles.Carotenoids,a group of important natural liposoluble pigments,are known for their diverse color spec...Natural colored cotton(NCC)offers a sustainable,dye-free,and eco-friendly alternative for producing colored textiles.Carotenoids,a group of important natural liposoluble pigments,are known for their diverse color spectrum.In this study,we successfully engineered the carotenoid biosynthesis pathway specifically in cotton fibers by utilizing a fiber-specific GbEXPA2 promoter and a CaMV 35S promoter to drive the expression of two key carotenoid biosynthesis genes,CrtB and CrtI,respectively.This approach resulted in the development of a golden fiber cotton germplasm enriched withβ-carotene.Notably,the pigmentation was predominantly observed during the early developmental stages of the fiber(5–20 d post-anthesis).While the presence of carotenoids had no significant effect on plant architecture and growth,it positively influenced the fiber elongation rate,albeit with a slight reduction in fiber length and strength.This study represents a pioneering strategy for the future development of NCCs through carotenoid biofortification.展开更多
Okara is produced in large quantities annually in China,but much of it is discarded due to its high content of indigestible dietary fiber(DF),contributing to significant environmental challenges.Recognizing the undere...Okara is produced in large quantities annually in China,but much of it is discarded due to its high content of indigestible dietary fiber(DF),contributing to significant environmental challenges.Recognizing the underexplored medicinal potential of DF,we developed an efficient fermentation method to enhance the bioavailability of okara fiber.In this study,Pediococcus acidilactici IFJ-1,which has strong enzymatic production capabilities and beneficial effects on gastrointestinal flora modulation,was selected to ferment okara.Results showed decreases in viscosity and particle size,optimized surface structure,improved thermal stability and hydration properties,and a significant increase in soluble DF content from 1.85%to 3.91%.To evaluate the physiological effects,hyperlipidemic mouse models were established and subjected to dietary interventions utilizing okara and fermented okara to measure changes in physicochemical parameters,gut microbiota composition,and lipid metabolism.The dietary intervention was effective,particularly in the fermented okara group,showing a 7.3%weight loss,improved blood lipids(triglycerides:‒39.8%,total cholesterol:‒12.8%,low-density lipoprotein cholesterol:‒34.2%,high-density lipoprotein cholesterol:+26.2%),and a 22.2%lower liver index.Gut microbiota analysis revealed that fermented okara positively modulated the microbial community by increasing the abundance of beneficial bacteria(e.g.,Bacteroidota)and reducing the abundance of obesity-associated bacteria(e.g.,Bacillota).Lipid metabolism profiling further demonstrated that fermented okara downregulated harmful lipids(e.g.,(O-acyl)-ω-hydroxy fatty acids,ceramides,and diacylglycerols)while upregulating beneficial phospholipids(e.g.,phosphatidylinositol,phosphatidylserine,phosphatidylethanolamine,lysophosphatidylinositol and lysophosphatidic acid).This study highlights a novel approach for enhancing DF utilization through fermentation,providing valuable insights into strategies for preventing obesity and metabolic diseases.展开更多
High-fat diets(HFD)disrupt lipid homeostasis,posing major public health risks.This study investigated the effect of ACA-DK,an insoluble dietary fiber derived from Antrodia camphorata,on HFD-induced dyslipidemia.We dem...High-fat diets(HFD)disrupt lipid homeostasis,posing major public health risks.This study investigated the effect of ACA-DK,an insoluble dietary fiber derived from Antrodia camphorata,on HFD-induced dyslipidemia.We demonstrate that ACA-DK effectively alleviates HFD-induced dyslipidemia in mice,counteracting metabolic disorders,aberrant blood lipids,and weight gain.Mechanistically,ACA-DK modulates triglycerides,phosphatidylcholine,and phosphatidylethanolamine via glycerophospholipid/choline/linoleic acid metabolism pathways,while rectifying gut dysbiosis through selective reduction of pro-inflammatory genera(Oscillibacter,Ruminiclostridium,Negativibacillus,Ruminococcaceae and Helicobacter).Integrated analysis identifies Ruminococcaceae and Helicobacter as key mediators of ACA-DK's lipid-regulatory effects,establishing microbiota-directed therapy as a strategy against dyslipidemia.We thus propose ACA-DK as a microbiota-directed dual-target therapy,simultaneously reprogramming host lipid metabolism and gut ecology to combat diet-induced metabolic diseases.These findings suggest that ACA-DK is a promising prebiotic dietary fiber for ameliorating HFD-induced lipid metabolic disorders,with potential for future development into functional foods or supplements.展开更多
Materials exhibiting broadband nonlinear optical responses are critically important for ultrafast photonics applications,particularly as saturable absorbers(SAs)that facilitate broadband optical pulse generation.In th...Materials exhibiting broadband nonlinear optical responses are critically important for ultrafast photonics applications,particularly as saturable absorbers(SAs)that facilitate broadband optical pulse generation.In this study,tea polyphenolpolyvinyl alcohol(TP-PVA)composite films are synthesized via a polymer embedding method and employed as SAs to initiate ultrafast pulse operation in fiber lasers.The TP-PVA SA film exhibits excellent broadband saturable absorption performance at wavelengths of 1.0μm,1.5μm,and 2.0μm,with modulation depths of 54.21%,41.41%,and 51.16%,respectively.Stable passively mode-locked pulses with pulse widths of 588 fs,419 fs,and 743 fs are generated in Yb-,Er-,and Tm-doped fiber lasers,respectively.This work confirms the effective performance of TP-PVA as a broadband SA,and establishes a foundation for the integration of novel and sustainable materials within ultrafast photonic systems.The approach paves the way for developing compact broadband ultrafast laser systems operating in the near-infrared spectral region.展开更多
We achieved an ultra-flat broad spectrum output with a 20-dB bandwidth of 77.85 nm in a double-clad Yb-doped fiber laser.The intensity difference between the highest and lowest points of the spectrum indicates a flatn...We achieved an ultra-flat broad spectrum output with a 20-dB bandwidth of 77.85 nm in a double-clad Yb-doped fiber laser.The intensity difference between the highest and lowest points of the spectrum indicates a flatness better than4 dB.More notably,this ultra-flat broad spectrum maintains a stable single-pulse mode-locking state.With the increase of pump power,an ultra-wide spectrum with a 20-dB bandwidth approaching 100 nm was formed at a pump power of 2.25 W.Additionally,we obtained a 9-pulse mode-locked state at another PC station with the same pump,which is the highest number of stable mode-locked pulse bursts observed so far with a first-order Raman frequency shift.This fiber laser shows its benefits of ultra-flat broad spectrum,high stability,and ease of fabrication,which provides a new method of obtaining the broadband light source for multiple practical applications.展开更多
The planar force model of prepreg,initially established based on the principle of minimum potential energy and the Rayleigh-Ritz method,was improved by considering the difference between the tensile and compressive mo...The planar force model of prepreg,initially established based on the principle of minimum potential energy and the Rayleigh-Ritz method,was improved by considering the difference between the tensile and compressive moduli in the direction of the prepreg fibers.Compressivetensile stress distribution coefficients were also established.Combined with tests on the effect of process parameters on interlayer tack,a theoretical prediction model for the turning radius related to process parameters was developed,and the impact of prepreg interlayer tack force on the minimum turning radius was analyzed.A finite element simulation model for prepreg curve placement was created to study the size and distribution patterns of folds generated during the prepreg turning process.A minimum turning radius test was conducted to establish evaluation criteria for surface defects in curve placement and verify the accuracy of the minimum turning radius prediction model.Based on this,a prediction method for the minimum turning radius of prepreg related to process parameters was established,providing constraints for the trajectory design of variable-stiffness placement composites.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.
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.
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.
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.
基金supported by the Deutsche Forschungsgemeinschaft(DFG),TRR274(Project ID 408885537,Sy Nergy,EXC 2145/ID 390857198,to FMB)。
文摘The remodeling of axonal connections following injury is an important feature driving functional recovery.The reticulospinal tract is an interesting descending motor tract that contains both excitatory and inhibitory fibers.While the reticulospinal tract has been shown to be particularly prone to axonal growth and plasticity following injuries of the spinal cord,the differential capacities of excitatory and inhibitory fibers for plasticity remain unclear.As adaptive axonal plasticity involves a sophisticated interplay between excitatory and inhibitory input,we investigated in this study the plastic potential of glutamatergic(vGlut2)and GABAergic(vGat)fibers originating from the gigantocellular nucleus and the lateral paragigantocellular nucleus,two nuclei important for locomotor function.Using a combination of viral tracing,chemogenetic silencing,and AI-based kinematic analysis,we investigated plasticity and its impact on functional recovery within the first 3 weeks following injury,a period prone to neuronal remodeling.We demonstrate that,in this time frame,while vGlut2-positive fibers within the gigantocellular and lateral paragigantocellular nuclei rewire significantly following cervical spinal cord injury,vGat-positive fibers are rather unresponsive to injury.We also show that the acute silencing of excitatory axonal fibers which rewire in response to lesions of the spinal cord triggers a worsening of the functional recovery.Using kinematic analysis,we also pinpoint the locomotion features associated with the gigantocellular nucleus or lateral paragigantocellular nucleus during functional recovery.Overall,our study increases the understanding of the role of the gigantocellular and lateral paragigantocellular nuclei during functional recovery following spinal cord injury.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61975141,61575137,and61675144)。
文摘We investigate theoretically and experimentally the chaotic dynamics of visible-wavelength all-fiber ring laser.The100-m 630 HP fibers are used to ensure high non-linearity.A 4-m Pr^(3+)/Yb^(3+)-co-doped ZBLAN fiber provides the gain.The chaotic laser was pumped by the laser diodes with the maximum power of 150 mW at the wavelength of 850 nm.The peak fluorescence spectrum of Pr^(3+)/Yb^(3+)-co-doped ZBLAN fiber at the wavelength of 635 nm shows that the visiblewavelength fiber laser can be achieved by synergistic energy transfer between Pr~(3+)and Yb^(3+)ions.The chaotic fiber laser is generated by adjusting the pump power,polarization controller and the auto-correlation,permutation entropy,skewness,and kurtosis were used to analyze the characteristics of chaotic laser.The noise-like time series and delta-like auto-correlation curve indicate the chaotic output.The complexity and randomness of time series are analyzed by the permutation entropy,skewness,and kurtosis.The result shows that chaotic dynamics is stable when the pump power exceeds a certain value.The visible chaotic all-fiber laser has high stability and can be applied for real-time monitoring and sensing.We believe that this approach may also be feasible for other materials for emission in the visible range.
基金Funded by the National Natural Science Foundation of China(No.51236003)the Natural Science Foundation of Gansu Province(No.1506RJZA076)。
文摘As the speeds of trains increase,higher demands are placed on brake materials.In order to overcome the thermal degradation phenomenon of brake pads during high-speed braking,we prepared copper fiber reinforced alkali-activated slag composite(AASC)friction materials by hot-pressing method,using slag as matrix,Na_(2)SiO_(3)·9H_(2)O as alkali excitant,copper fiber as reinforcement,and graphite as friction modifier.The results show that the AASC prepared by hot-pressing method has undergone alkali-activated reaction and has geopolymer amorphous characteristics as the conventional cast molding AASC by XRD analysis.The addition of copper fibers can improve the mechanical strength and toughness of the composites substantially,and the AASC has the highest flexural strength,compressive strength and impact toughness when the volume fraction of copper fibers reaches 25 vol%.Toughening mechanisms such as drawing,bridging and crack deflection of copper fibers in composites were analyzed by SEM morphology.Addition of appropriate amount of graphite to AASC can effectively reduce the wear rate and improve the stability of the material friction coefficient.The coefficient of friction also remains stable in the high-speed friction experiments without thermal degradation.Therefore,copper fiber reinforced AASC friction materials prepared by hot-pressing method has good mechanical and friction properties.
基金supported by the National Natural Science Foundation of China (Grant No. 5186504)the University Science Foundation for Young Science and Technology Talents in Inner Mongolia Autonomous Region of China (Grant No. NJYT22078)+2 种基金the Basic Scientific Research Expenses Program of Universities directly under Inner Mongolia Autonomous Region (Grant No. JY20220059)the Inner Mongolia Autonomous Region ‘Grassland Talent’ project Young Innovative Talent Training Program Level ⅠBasic Research Expenses of Universities directly under the Inner Mongolia Autonomous Region (Grant No. ZTY2023040)。
文摘To develop a suitable production process for fiber reinforced investment casting shell mold,three methods were studied:the traditional method(M_(1)),the method of adding fiber into silica sol with mechanical stirring and ultrasonic agitation(M_(2)),and the method of adding fiber into slurry with mechanical stirring and ultrasonic agitation for durations of 3,15,30,and 45 min(M_(3)).The bending strength,high-temperature self-load deformation,and thermal conductivity of the shell molds were investigated.The results reveal that the enhancement of fiber dispersion through ultrasonic agitation improves the comprehensive performance of the shell molds.The maximum green bending strength of the shell mold by M_(2) reaches 3.29 MPa,which is 29% higher than that of the shell mold prepared by M_(1).Moreover,the high-temperature self-load deformation of the shell mold is reduced from 0.62% to 0.44%.In addition,simultaneous ultrasonic agitation and mechanical stirring effectively shorten the slurry preparation time while maintaining comparable levels of fiber dispersion.With the process M_(3)-45 min,the fillers are uniformly dispersed in the slurry,and the fired bending strength and the high-temperature self-load deformation reach 6.25 MPa and 0.41%,respectively.Therefore,the proposed ultrasonic agitation route is promising for the fabrication of fiber-reinforced shell molds with excellent fibers dispersion.
基金the financial support provided by Universiti Putra Malaysiasupported by the Matching Grant(9300489).
文摘This review draws attention to the innovative use of arrowroot(Maranta arundinacea)fiber as a unique and underutilized biomass source for nanocrystalline cellulose(NCC)-based nanocomposites,presenting a noteworthy alternative to extensively researched materials like wood pulp,bacterial cellulose,and chemically modified NCCs.In contrast to traditional sources,arrowroot possesses a naturally elevated cellulose and diminished lignin content,facilitating more effective NCC extraction requiring reduced chemical input and enabling environmentally friendly processing techniques.The review evaluates the performance of arrowroot-derived nanocomposites against systems documented in the literature,including NCC-based shape memory composites and nanoparticle-reinforced films,demonstrating enhanced tensile strength,improved moisture barrier properties,and thermal stability,as well as potential piezoelectric response.This study recognizes arrowroot as a viable option in the biomass-based nanocellulose sector,providing ecological and functional benefits while tackling significant issues such as process scalability and feedstock variability,thereby offering important insights for the advancement of sustainable materials.
基金supported by grants from the National Natural Science Foundation of China(32170271,32470277)the Natural Science Foundation of Henan Province(222300420024).
文摘Natural colored cotton(NCC)offers a sustainable,dye-free,and eco-friendly alternative for producing colored textiles.Carotenoids,a group of important natural liposoluble pigments,are known for their diverse color spectrum.In this study,we successfully engineered the carotenoid biosynthesis pathway specifically in cotton fibers by utilizing a fiber-specific GbEXPA2 promoter and a CaMV 35S promoter to drive the expression of two key carotenoid biosynthesis genes,CrtB and CrtI,respectively.This approach resulted in the development of a golden fiber cotton germplasm enriched withβ-carotene.Notably,the pigmentation was predominantly observed during the early developmental stages of the fiber(5–20 d post-anthesis).While the presence of carotenoids had no significant effect on plant architecture and growth,it positively influenced the fiber elongation rate,albeit with a slight reduction in fiber length and strength.This study represents a pioneering strategy for the future development of NCCs through carotenoid biofortification.
基金supported by the Key Special Projects of the Ministry of Science and Technology(SQ2020YFF0404523)the North Anhui Soybean Advantageous Characteristic Industry Cluster Project(2023CYJQ013)+2 种基金the National Natural Science Foundation of China(32172162)the Key Genetic Technologies Research and Development Program of Hefei(2021GJ075)the Young Talents Program of Anhui Academy of Agricultural Science(QNYC-202122).
文摘Okara is produced in large quantities annually in China,but much of it is discarded due to its high content of indigestible dietary fiber(DF),contributing to significant environmental challenges.Recognizing the underexplored medicinal potential of DF,we developed an efficient fermentation method to enhance the bioavailability of okara fiber.In this study,Pediococcus acidilactici IFJ-1,which has strong enzymatic production capabilities and beneficial effects on gastrointestinal flora modulation,was selected to ferment okara.Results showed decreases in viscosity and particle size,optimized surface structure,improved thermal stability and hydration properties,and a significant increase in soluble DF content from 1.85%to 3.91%.To evaluate the physiological effects,hyperlipidemic mouse models were established and subjected to dietary interventions utilizing okara and fermented okara to measure changes in physicochemical parameters,gut microbiota composition,and lipid metabolism.The dietary intervention was effective,particularly in the fermented okara group,showing a 7.3%weight loss,improved blood lipids(triglycerides:‒39.8%,total cholesterol:‒12.8%,low-density lipoprotein cholesterol:‒34.2%,high-density lipoprotein cholesterol:+26.2%),and a 22.2%lower liver index.Gut microbiota analysis revealed that fermented okara positively modulated the microbial community by increasing the abundance of beneficial bacteria(e.g.,Bacteroidota)and reducing the abundance of obesity-associated bacteria(e.g.,Bacillota).Lipid metabolism profiling further demonstrated that fermented okara downregulated harmful lipids(e.g.,(O-acyl)-ω-hydroxy fatty acids,ceramides,and diacylglycerols)while upregulating beneficial phospholipids(e.g.,phosphatidylinositol,phosphatidylserine,phosphatidylethanolamine,lysophosphatidylinositol and lysophosphatidic acid).This study highlights a novel approach for enhancing DF utilization through fermentation,providing valuable insights into strategies for preventing obesity and metabolic diseases.
基金supported by the National Science Fund for Distinguished Young Scholars(32025029)the Natural Science Foundation of China(32272364)Shanghai Engineering Research Center of food microbiology program(19DZ2281100).
文摘High-fat diets(HFD)disrupt lipid homeostasis,posing major public health risks.This study investigated the effect of ACA-DK,an insoluble dietary fiber derived from Antrodia camphorata,on HFD-induced dyslipidemia.We demonstrate that ACA-DK effectively alleviates HFD-induced dyslipidemia in mice,counteracting metabolic disorders,aberrant blood lipids,and weight gain.Mechanistically,ACA-DK modulates triglycerides,phosphatidylcholine,and phosphatidylethanolamine via glycerophospholipid/choline/linoleic acid metabolism pathways,while rectifying gut dysbiosis through selective reduction of pro-inflammatory genera(Oscillibacter,Ruminiclostridium,Negativibacillus,Ruminococcaceae and Helicobacter).Integrated analysis identifies Ruminococcaceae and Helicobacter as key mediators of ACA-DK's lipid-regulatory effects,establishing microbiota-directed therapy as a strategy against dyslipidemia.We thus propose ACA-DK as a microbiota-directed dual-target therapy,simultaneously reprogramming host lipid metabolism and gut ecology to combat diet-induced metabolic diseases.These findings suggest that ACA-DK is a promising prebiotic dietary fiber for ameliorating HFD-induced lipid metabolic disorders,with potential for future development into functional foods or supplements.
基金supported by the Opening Foundation of Hubei Key Laboratory for New Textile Materials and Applications Research(Grant No.FZXCL202410)the Key Project of Science and Technology Research Program of Hubei Provincial Department of Education,China(Grant No.D20231704)+1 种基金Wuhan Textile University(Grant No.523058)the Foundation of Wuhan Textile University(Grant No.K24058)。
文摘Materials exhibiting broadband nonlinear optical responses are critically important for ultrafast photonics applications,particularly as saturable absorbers(SAs)that facilitate broadband optical pulse generation.In this study,tea polyphenolpolyvinyl alcohol(TP-PVA)composite films are synthesized via a polymer embedding method and employed as SAs to initiate ultrafast pulse operation in fiber lasers.The TP-PVA SA film exhibits excellent broadband saturable absorption performance at wavelengths of 1.0μm,1.5μm,and 2.0μm,with modulation depths of 54.21%,41.41%,and 51.16%,respectively.Stable passively mode-locked pulses with pulse widths of 588 fs,419 fs,and 743 fs are generated in Yb-,Er-,and Tm-doped fiber lasers,respectively.This work confirms the effective performance of TP-PVA as a broadband SA,and establishes a foundation for the integration of novel and sustainable materials within ultrafast photonic systems.The approach paves the way for developing compact broadband ultrafast laser systems operating in the near-infrared spectral region.
基金Project supported by the National Natural Science Foundation of China(Grant No.12204132)the Natural Science Foundation of Shandong Province,China(Grant No.ZR2021MF122)+1 种基金Shandong Province TechnologyBased SME Innovation Enhancement Project(Grant No.2024TSGC0715)the Postgraduate Education Reform Project of Shandong Province,China(Grant No.SDYJSJGC2024107)。
文摘We achieved an ultra-flat broad spectrum output with a 20-dB bandwidth of 77.85 nm in a double-clad Yb-doped fiber laser.The intensity difference between the highest and lowest points of the spectrum indicates a flatness better than4 dB.More notably,this ultra-flat broad spectrum maintains a stable single-pulse mode-locking state.With the increase of pump power,an ultra-wide spectrum with a 20-dB bandwidth approaching 100 nm was formed at a pump power of 2.25 W.Additionally,we obtained a 9-pulse mode-locked state at another PC station with the same pump,which is the highest number of stable mode-locked pulse bursts observed so far with a first-order Raman frequency shift.This fiber laser shows its benefits of ultra-flat broad spectrum,high stability,and ease of fabrication,which provides a new method of obtaining the broadband light source for multiple practical applications.
基金co-supported by the National Natural Science Foundation of China(Nos.U24A20118,52175311,52175133,12472131,52405149)the Fundamental Research Funds for the Central Universities,China(Nos.JZ2023HGPB0289,JZ2023HGQA0475,PA2024GDSK0063)the Anhui Provincial Natural Science Foundation,China(No.2408085QE156)。
文摘The planar force model of prepreg,initially established based on the principle of minimum potential energy and the Rayleigh-Ritz method,was improved by considering the difference between the tensile and compressive moduli in the direction of the prepreg fibers.Compressivetensile stress distribution coefficients were also established.Combined with tests on the effect of process parameters on interlayer tack,a theoretical prediction model for the turning radius related to process parameters was developed,and the impact of prepreg interlayer tack force on the minimum turning radius was analyzed.A finite element simulation model for prepreg curve placement was created to study the size and distribution patterns of folds generated during the prepreg turning process.A minimum turning radius test was conducted to establish evaluation criteria for surface defects in curve placement and verify the accuracy of the minimum turning radius prediction model.Based on this,a prediction method for the minimum turning radius of prepreg related to process parameters was established,providing constraints for the trajectory design of variable-stiffness placement composites.
