Decreasing mode coupling coefficient(κ) is an effective approach to suppress the inter-core crosstalk. Therefore, we deploy a low index rod and rectangle trench in the middle of two neighboring cores to reduce κ so ...Decreasing mode coupling coefficient(κ) is an effective approach to suppress the inter-core crosstalk. Therefore, we deploy a low index rod and rectangle trench in the middle of two neighboring cores to reduce κ so that the overlap of electric field distribution can be suppressed. We also propose approximate analytical solution(AAS) for κ of two crosstalk suppression models, which are two cores with one low index rod deployed in the middle and two cores with one low index rectangle trench deployed in the middle. We then do some modification for the results obtained by AAS and the modified results are proved to agree well with that obtained by finite element method(FEM). Therefore, we can use the modified AAS to get inter-core crosstalk for abovementioned two models quickly.展开更多
Quantum key distribution(QKD)is a secure communication method for sharing symmetric cryptographic keys based on the principles of quantum physics.Its integration into the fiber-optic network infrastructure is importan...Quantum key distribution(QKD)is a secure communication method for sharing symmetric cryptographic keys based on the principles of quantum physics.Its integration into the fiber-optic network infrastructure is important for ensuring privacy in optical communications.Multi-core fibers(MCFs),the likely building blocks of future high-capacity optical networks,offer new opportunities for such integration.Here,we experimentally demonstrate,for the first time,the coexistence of discrete-variable QKD and high-throughput classical communication in the C-band over a fielddeployed MCF with industry standard cladding diameter of 125μm.Specifically,we demonstrate successful secure-key establishment in one core of a 25.2-km uncoupled-core MCF,while simultaneously loading the remaining three cores with full C-band counter-propagating classical traffic at an aggregate net rate of 110.8 Tb/s.By proposing and experimentally validating an improved analytical model for inter-core spontaneous Raman scattering noise,we find that this configuration is optimal for our deployed MCF link as it is immune to four-wave mixing,that becomes relevant when the quantum and classical signals are propagating in the same direction.Our findings make an important step forward in demonstrating the integration of QKD and classical transmission in uncoupled-core multicore fibers for next-generation optical communication networks.展开更多
In this Letter, we propose two crosstalk-aware routing, core, and spectrum assignment （CA-RCSA） algorithms for spatial division multiplexing enabled elastic optical networks （SDM-EONs） with multi-core fibers. Firs...In this Letter, we propose two crosstalk-aware routing, core, and spectrum assignment （CA-RCSA） algorithms for spatial division multiplexing enabled elastic optical networks （SDM-EONs） with multi-core fibers. First, the RCSA problem is modeled, and then a metric, i.e., CA spectrum compactness （CASC）, is designed to measure the spectrum status in SDM-EONs. Based on CASC, we propose two CA-RCSA algorithms, the first-fit （FF） CASC algorithm and the random-fit （RF） CASC algorithm. Simulation results show that our proposed algorithms can achieve better performance than the baseline algorithm in terms of blocking probability and spectrum utilization, with FF-CASC providing the best performance.展开更多
Space-division multiplexing based on few-mode multi-core fiber(FM-MCF)technology is expected to break the Shannon limit of a single-mode fiber.However,an FM-MCF is compact,and it is difficult to couple the beam to eac...Space-division multiplexing based on few-mode multi-core fiber(FM-MCF)technology is expected to break the Shannon limit of a single-mode fiber.However,an FM-MCF is compact,and it is difficult to couple the beam to each fiber core.3D waveguide devices have the advantages of low insertion loss and low cross talk in separating various spatial paths of multi-core fibers.Designing a 3D waveguide device for an FM-MCF requires considering not only higher-order modes transmission,but also waveguide bending.We propose and demonstrate a 3D waveguide device fabricated by femtosecond laser direct writing for various spatial path separations in an FM-MCF.The 3D waveguide device couples the LP01 and LP11a modes to the FM-MCF with an insertion loss below 3 dB and cross talk between waveguides below-36 dB.To test the performance of the 3D waveguide device,we demonstrate four-channel multiplexing communication with two LP modes and two cores in a 1-km few-mode sevencore fiber.The bit error rate curves show that the different degrees of bending of the waveguides result in a difference of approximately 1 dB in the power penalty.Femtosecond laser direct writing fabrication enables 3D waveguide devices to support high-order LP modes transmission and further improves FM-MCF communication.展开更多
Naturally degradable capsule provides a platform for sustained fragrance release.However,practical challenges such as low encapsulation efficiency and difficulty in sustained release are still limited in using fragran...Naturally degradable capsule provides a platform for sustained fragrance release.However,practical challenges such as low encapsulation efficiency and difficulty in sustained release are still limited in using fragranceloaded capsules.In this work,the natural materials sodium alginate and gelatine are dissolved and act as the aqueous phase,lavender is dissolved in caprylic/capric triglyceride(GTCC)as the oil phase,and SiO_(2) nanoparticles with neutralwettability as a solid emulsifier to form O/W Pickering emulsions simultaneously.Finally,multi-core capsules are prepared using the drop injection method with emulsions as templates.The results show that the capsules have been successfully prepared with a spherical morphology and multi-core structure,and the encapsulation rate of multi-core capsules can reach up to 99.6%.In addition,the multi-core capsules possess desirable sustained release performance,the cumulative sustained release rate of fragrance at 25℃over 49 days is only 32.5%.It is attributed to the significant protection of multi-core structure,Pickering emulsion nanoparticle membranes,and hydrogel network shell for encapsulated fragrance.This study is designed to deliver a new strategy for using sustained-release technology with fragrance in food,cosmetics,textiles,and other fields.展开更多
In this paper, the influencing factors that affect few-mode and multi core optical fiber channel are analyzed in a comprehensive way. The theoretical modeling and computer simulation of the information channel are car...In this paper, the influencing factors that affect few-mode and multi core optical fiber channel are analyzed in a comprehensive way. The theoretical modeling and computer simulation of the information channel are carried out and then the modeling scheme of few-mode multicore optical fiber channel based on non-uniform mode field distribution is put forward. The proposed modeling scheme can not only exponentially increases the system capacity through fewmode multi-core optical fiber channel, but has better transmission performance compared to the channel of the same type to the uniform channel revealing from the simulation results.展开更多
A large mode area multi-core orbital angular momentum(OAM)transmission fiber is designed and optimized by neural network and optimization algorithms.The neural network model has been established first to predict the o...A large mode area multi-core orbital angular momentum(OAM)transmission fiber is designed and optimized by neural network and optimization algorithms.The neural network model has been established first to predict the optical properties of multi-core OAM transmission fibers with high accuracy and speed,including mode area,nonlinear coefficient,purity,dispersion,and effective index difference.Then the trained neural network model is combined with different particle swarm optimization(PSO)algorithms for automatic iterative optimization of multi-core structures respectively.Due to the structural advantages of multi-core fiber and the automatic optimization process,we designed a number of multi-core structures with high OAM mode purity(>95%)and ultra-large mode area(>3000µm^(2)),which is larger by more than an order of magnitude compared to the conventional ring-core OAM transmission fibers.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
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
The thermal properties of photonic crystal fiber(PCF) laser with 18 circularly distributed cores are investigated by using full-vector finite element method(FEM).The results show that the 18-core PCF has a more effect...The thermal properties of photonic crystal fiber(PCF) laser with 18 circularly distributed cores are investigated by using full-vector finite element method(FEM).The results show that the 18-core PCF has a more effective thermal dispersion construction compared with the single core PCF and 19-core PCF.In addition,the temperature distribution of 18-core PCF laser with different thermal loads is simulated.The results show that the core temperature approaches the fiber drawing value of 1800 K approximately when the thermal load is above 80 W/m which corresponds to the pumping power of 600 W approximately,while the coating temperature approaches the damage value of about 550 K when the thermal load is above 15 W/m which corresponds to the pumping power of 110 W approximately.Therefore the fiber cooling is necessary to achieve power scaling.Compared with other different cooling systems,the copper cooling scheme is found to be an effective method to reduce the thermal effects.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
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
Fiber photodetectors(FPDs)with high deformability,flexible designability,and seamless integrability with everyday textiles hold tremendous potential for the nextgeneration wearable optoelectronics.Inorganic semiconduc...Fiber photodetectors(FPDs)with high deformability,flexible designability,and seamless integrability with everyday textiles hold tremendous potential for the nextgeneration wearable optoelectronics.Inorganic semiconductors(ISCs)are considered the ideal building block to design and govern the functions of FPDs owing to their superior electrical and optical properties.Recent developments in wearable technology of ISCs,especially in fiber form factor,have driven the creation of various FPDs with smart capabilities,from light sensing,information interfacing,to sophisticated logic operating,revolutionizing human-machine interaction paradigms in many emerging fields.Herein,we present a comprehensive review of the recent progress of ISCbased FPDs.Firstly,key design principles for ISC-based FPDs are explored,encompassing material selection,fabrication technologies,device architectures,and textile integration strategies.Then,how defect engineering,alignment engineering,and heterojunction engineering of ISCs can control the optoelectronic performance of FPDs is examined.Following this,potential wearable applications of ISC-based FPDs in optical communication,image sensing,and health monitoring are analyzed.Finally,the challenges and perspectives for the design of high-performance ISC-based FPDs are outlined.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
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
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
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
The development of high-performance bifunctional electrocatalysts is crucial for advancing zinc-air batteries.However,the fundamentally distinct mechanisms of the oxygen reduction and evolution reactions(ORR/OER)hinde...The development of high-performance bifunctional electrocatalysts is crucial for advancing zinc-air batteries.However,the fundamentally distinct mechanisms of the oxygen reduction and evolution reactions(ORR/OER)hinder the simultaneous realization of high activity within a single catalyst.Herein,we propose a spatial decoupling strategy to overcome this limitation by engineering isolated Fe singleatoms and Fe-Ir dual-atom pairs on a nitrogen-doped carbon matrix(Fe/FeIr-NC).In this architecture,Fe single atoms serve as ORR centers,while Fe-Ir pairs with tunable spacing are tailored for OER,enabling complete functional separation and independent optimization of the reactions.As a result,the catalyst delivers an ORR half-wave potential of 0.91 V and an OER overpotential of 250 mV at 10 mA cm^(-2),yielding a record-low bifunctional gap(ΔE=0.57 V)that outperforms all reported single-and dual-atom catalysts.A flexible fiber zincair battery was developed based on this catalyst,delivering a peak power density of 3920 W kg^(-1),along with a 1.4-fold increase in energy efficiency and a 2.6-fold extension in cycle life compared to the commercial Pt/C+IrO_(2)benchmark.This work not only breaks the traditional activity trade-off in bifunctional catalysis but also offers a promising route toward high-performance power sources for wearable electronics.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
A multi-stage stress relaxation test was performed on a granodiorite sample to understand the deformation process prior to the macroscopic failure of brittle rocks,as well as the transient response during stress relax...A multi-stage stress relaxation test was performed on a granodiorite sample to understand the deformation process prior to the macroscopic failure of brittle rocks,as well as the transient response during stress relaxation.Distributed optical fiber sensing was used to measure strains across the sample surface by helically wrapping the single-mode fiber around the cylindrical sample.Close agreement was observed between the circumferential strains obtained from the optical fibers and the extensometer.The reconstructed full-field strain contours show strain heterogeneity from the crack closure phase,and the strains in the later deformation phase are dominantly localized within the former high-strain zone.The Gini coefficient was used to quantify the degree of strain localization and shows an initial increase during the crack closure phase,a decrease during the linear elastic phase,and a subsequent increase during the post-yielding phase.This behavior corresponds to a process of initial localization from an imperfect boundary condition,homogenization,and eventual relocalization prior to the macroscopic failure of the sample.The transient strain rate decay during the stress relaxation phase was quantified using the p-value in the“Omori-like"power law function.A higher initial stress at the onset of relaxation results in a lower p-value,indicating a slower strain rate decay.As the sample approaches macroscopic failure,the lowest p-value shifts from the most damaged zone to adjacent areas,suggesting stress redistribution or crack propagation in deformed crystalline rocks under stress relaxation conditions.展开更多
基金supported by National B a-sic Research Program of China(Grant No.2012CB315905)National Natural Science Foundation of China(Grant No.61501027)+1 种基金China Postdoctoral Science Foundation(Grant No.2015M570934)Fundamental Research Funds for the Central Universities(Grant No.FRF-TP-15-031A1)
文摘Decreasing mode coupling coefficient(κ) is an effective approach to suppress the inter-core crosstalk. Therefore, we deploy a low index rod and rectangle trench in the middle of two neighboring cores to reduce κ so that the overlap of electric field distribution can be suppressed. We also propose approximate analytical solution(AAS) for κ of two crosstalk suppression models, which are two cores with one low index rod deployed in the middle and two cores with one low index rectangle trench deployed in the middle. We then do some modification for the results obtained by AAS and the modified results are proved to agree well with that obtained by finite element method(FEM). Therefore, we can use the modified AAS to get inter-core crosstalk for abovementioned two models quickly.
基金funded by the European Commission through European Union—Next Generation EU,under the Italian National Recovery and Resilience Plan,Mission 4,Component 2,Investment 1.3,CUP B53C22003970001,partnership on“Telecommunications of the Future”(PE00000001—program“RESTART”)in the Digital Europe Program under project QUID(Quantum Italy Deployment)Grant Agreement 101091408funding from the European Commission through ERC StG,QOMUNE,Grant Agreement 101077917.
文摘Quantum key distribution(QKD)is a secure communication method for sharing symmetric cryptographic keys based on the principles of quantum physics.Its integration into the fiber-optic network infrastructure is important for ensuring privacy in optical communications.Multi-core fibers(MCFs),the likely building blocks of future high-capacity optical networks,offer new opportunities for such integration.Here,we experimentally demonstrate,for the first time,the coexistence of discrete-variable QKD and high-throughput classical communication in the C-band over a fielddeployed MCF with industry standard cladding diameter of 125μm.Specifically,we demonstrate successful secure-key establishment in one core of a 25.2-km uncoupled-core MCF,while simultaneously loading the remaining three cores with full C-band counter-propagating classical traffic at an aggregate net rate of 110.8 Tb/s.By proposing and experimentally validating an improved analytical model for inter-core spontaneous Raman scattering noise,we find that this configuration is optimal for our deployed MCF link as it is immune to four-wave mixing,that becomes relevant when the quantum and classical signals are propagating in the same direction.Our findings make an important step forward in demonstrating the integration of QKD and classical transmission in uncoupled-core multicore fibers for next-generation optical communication networks.
基金supported by the National Natural Science Foundation of China(Nos.61571058 and 61501049)the National 863 Project of China(No.2015AA015503)+2 种基金the State Key Laboratory of Information Photonics and Optical Communications(Nos.IPOC2014ZZ03 and IPOC2015ZT01)the Chinese Scholarship Council(CSC),BUPT Excellent Ph.D.Students Foundation(No.CX2015307)the NSF Project(No.CNS-1302645).
文摘In this Letter, we propose two crosstalk-aware routing, core, and spectrum assignment （CA-RCSA） algorithms for spatial division multiplexing enabled elastic optical networks （SDM-EONs） with multi-core fibers. First, the RCSA problem is modeled, and then a metric, i.e., CA spectrum compactness （CASC）, is designed to measure the spectrum status in SDM-EONs. Based on CASC, we propose two CA-RCSA algorithms, the first-fit （FF） CASC algorithm and the random-fit （RF） CASC algorithm. Simulation results show that our proposed algorithms can achieve better performance than the baseline algorithm in terms of blocking probability and spectrum utilization, with FF-CASC providing the best performance.
基金Guangdong Major Project of Basic Research(2020B0301030009)National Key Research and Development Program of China(2018YFB1801801,2018YFB1800901)+4 种基金National Natural Science Foundation of China(61935013,61975133,62075139,61705135,12047540,61835005,62175162,62105215)Natural Science Foundation of Guangdong Province(2020A1515011185)Science,Technology and Innovation Commission of Shenzhen Municipality(RCJC20200714114435063,KQJSCX20170727100838364,JCYJ20180507182035270,JCYJ20200109114018750)Shenzhen Peacock Plan(KQTD20170330110444030)Shenzhen University(2019075)。
文摘Space-division multiplexing based on few-mode multi-core fiber(FM-MCF)technology is expected to break the Shannon limit of a single-mode fiber.However,an FM-MCF is compact,and it is difficult to couple the beam to each fiber core.3D waveguide devices have the advantages of low insertion loss and low cross talk in separating various spatial paths of multi-core fibers.Designing a 3D waveguide device for an FM-MCF requires considering not only higher-order modes transmission,but also waveguide bending.We propose and demonstrate a 3D waveguide device fabricated by femtosecond laser direct writing for various spatial path separations in an FM-MCF.The 3D waveguide device couples the LP01 and LP11a modes to the FM-MCF with an insertion loss below 3 dB and cross talk between waveguides below-36 dB.To test the performance of the 3D waveguide device,we demonstrate four-channel multiplexing communication with two LP modes and two cores in a 1-km few-mode sevencore fiber.The bit error rate curves show that the different degrees of bending of the waveguides result in a difference of approximately 1 dB in the power penalty.Femtosecond laser direct writing fabrication enables 3D waveguide devices to support high-order LP modes transmission and further improves FM-MCF communication.
文摘Naturally degradable capsule provides a platform for sustained fragrance release.However,practical challenges such as low encapsulation efficiency and difficulty in sustained release are still limited in using fragranceloaded capsules.In this work,the natural materials sodium alginate and gelatine are dissolved and act as the aqueous phase,lavender is dissolved in caprylic/capric triglyceride(GTCC)as the oil phase,and SiO_(2) nanoparticles with neutralwettability as a solid emulsifier to form O/W Pickering emulsions simultaneously.Finally,multi-core capsules are prepared using the drop injection method with emulsions as templates.The results show that the capsules have been successfully prepared with a spherical morphology and multi-core structure,and the encapsulation rate of multi-core capsules can reach up to 99.6%.In addition,the multi-core capsules possess desirable sustained release performance,the cumulative sustained release rate of fragrance at 25℃over 49 days is only 32.5%.It is attributed to the significant protection of multi-core structure,Pickering emulsion nanoparticle membranes,and hydrogel network shell for encapsulated fragrance.This study is designed to deliver a new strategy for using sustained-release technology with fragrance in food,cosmetics,textiles,and other fields.
基金supports from National High Technology 863 Program of China(No.2013AA013403,2015AA015501,2015AA015502,2015AA015504)National NSFC(No.61425022/61522501/61307086/61475024/61275158/61201151/61275074/61372109)+4 种基金Beijing Nova Program(No.Z141101001814048)Beijing Excellent Ph.D.Thesis Guidance Foundation(No.20121001302)the Universities Ph.D.Special Research Funds(No.20120005110003/20120005120007)Fund of State Key Laboratory of IPOC(BUPT)P.R.China
文摘In this paper, the influencing factors that affect few-mode and multi core optical fiber channel are analyzed in a comprehensive way. The theoretical modeling and computer simulation of the information channel are carried out and then the modeling scheme of few-mode multicore optical fiber channel based on non-uniform mode field distribution is put forward. The proposed modeling scheme can not only exponentially increases the system capacity through fewmode multi-core optical fiber channel, but has better transmission performance compared to the channel of the same type to the uniform channel revealing from the simulation results.
基金supported by the National Natural Science Foundation of China(Nos.92048301,62020106004 and 11704283)in part by the Tianjin Municipal Education Commission(No.2018KJ146)in part by the Opening Foundation of Tianjin Key Laboratory of Optoelectronic Detection Technology and Systems(No.2019LODTS004).
文摘A large mode area multi-core orbital angular momentum(OAM)transmission fiber is designed and optimized by neural network and optimization algorithms.The neural network model has been established first to predict the optical properties of multi-core OAM transmission fibers with high accuracy and speed,including mode area,nonlinear coefficient,purity,dispersion,and effective index difference.Then the trained neural network model is combined with different particle swarm optimization(PSO)algorithms for automatic iterative optimization of multi-core structures respectively.Due to the structural advantages of multi-core fiber and the automatic optimization process,we designed a number of multi-core structures with high OAM mode purity(>95%)and ultra-large mode area(>3000µm^(2)),which is larger by more than an order of magnitude compared to the conventional ring-core OAM transmission fibers.
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.
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.
基金supported by the National Basic Research Program of China(No.2010CB327801)the Key Program of National Natural Science Foundation of China(No.60637010)the Natural Science Research Project in University of Hebei Province(No.Z2010163)
文摘The thermal properties of photonic crystal fiber(PCF) laser with 18 circularly distributed cores are investigated by using full-vector finite element method(FEM).The results show that the 18-core PCF has a more effective thermal dispersion construction compared with the single core PCF and 19-core PCF.In addition,the temperature distribution of 18-core PCF laser with different thermal loads is simulated.The results show that the core temperature approaches the fiber drawing value of 1800 K approximately when the thermal load is above 80 W/m which corresponds to the pumping power of 600 W approximately,while the coating temperature approaches the damage value of about 550 K when the thermal load is above 15 W/m which corresponds to the pumping power of 110 W approximately.Therefore the fiber cooling is necessary to achieve power scaling.Compared with other different cooling systems,the copper cooling scheme is found to be an effective method to reduce the thermal effects.
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financially supported by the National Key R&D Program of China(2023YFE0210800)National Natural Science Foundation of China(U21A2069,22305088)+4 种基金Natural Science Foundation of Hubei Province(JCZRQN202400929)Shenzhen Science and Technology Program(JCYJ20240813153403005,JCYJ20220818102215033)Guangdong Basic and Applied Basic Research Foundation(2023B1515120041)Open Research Fund of Suzhou Laboratory(SZLAB-1508-2024-ZD013)Guangdong HUST Industrial Technology Research Institute,Guangdong Provincial Key Laboratory of Manufacturing Equipment Digitization(2023B1212060012)。
文摘Fiber photodetectors(FPDs)with high deformability,flexible designability,and seamless integrability with everyday textiles hold tremendous potential for the nextgeneration wearable optoelectronics.Inorganic semiconductors(ISCs)are considered the ideal building block to design and govern the functions of FPDs owing to their superior electrical and optical properties.Recent developments in wearable technology of ISCs,especially in fiber form factor,have driven the creation of various FPDs with smart capabilities,from light sensing,information interfacing,to sophisticated logic operating,revolutionizing human-machine interaction paradigms in many emerging fields.Herein,we present a comprehensive review of the recent progress of ISCbased FPDs.Firstly,key design principles for ISC-based FPDs are explored,encompassing material selection,fabrication technologies,device architectures,and textile integration strategies.Then,how defect engineering,alignment engineering,and heterojunction engineering of ISCs can control the optoelectronic performance of FPDs is examined.Following this,potential wearable applications of ISC-based FPDs in optical communication,image sensing,and health monitoring are analyzed.Finally,the challenges and perspectives for the design of high-performance ISC-based FPDs are outlined.
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 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 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financially supported by the Zhejiang Provincial Natural Science Foundation of China(LMS25E030001)the Fundamental Research Funds of Zhejiang Sci-Tech University(25212142-Y and 23212200-Y)。
文摘The development of high-performance bifunctional electrocatalysts is crucial for advancing zinc-air batteries.However,the fundamentally distinct mechanisms of the oxygen reduction and evolution reactions(ORR/OER)hinder the simultaneous realization of high activity within a single catalyst.Herein,we propose a spatial decoupling strategy to overcome this limitation by engineering isolated Fe singleatoms and Fe-Ir dual-atom pairs on a nitrogen-doped carbon matrix(Fe/FeIr-NC).In this architecture,Fe single atoms serve as ORR centers,while Fe-Ir pairs with tunable spacing are tailored for OER,enabling complete functional separation and independent optimization of the reactions.As a result,the catalyst delivers an ORR half-wave potential of 0.91 V and an OER overpotential of 250 mV at 10 mA cm^(-2),yielding a record-low bifunctional gap(ΔE=0.57 V)that outperforms all reported single-and dual-atom catalysts.A flexible fiber zincair battery was developed based on this catalyst,delivering a peak power density of 3920 W kg^(-1),along with a 1.4-fold increase in energy efficiency and a 2.6-fold extension in cycle life compared to the commercial Pt/C+IrO_(2)benchmark.This work not only breaks the traditional activity trade-off in bifunctional catalysis but also offers a promising route toward high-performance power sources for wearable electronics.
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support of her postdoctoral research at the GFZ Helmholtz Centre for Geosciences.P.Pan acknowledges the financial support of the National Natural Science Foundation of China(Grant No.52339001)H.Hofmann and Y.Ji acknowledge the financial support of the Helmholtz Association's Initiative and Networking Fund for the Helmholtz Young Investigator Group ARES(contract number VH-NG-1516).
文摘A multi-stage stress relaxation test was performed on a granodiorite sample to understand the deformation process prior to the macroscopic failure of brittle rocks,as well as the transient response during stress relaxation.Distributed optical fiber sensing was used to measure strains across the sample surface by helically wrapping the single-mode fiber around the cylindrical sample.Close agreement was observed between the circumferential strains obtained from the optical fibers and the extensometer.The reconstructed full-field strain contours show strain heterogeneity from the crack closure phase,and the strains in the later deformation phase are dominantly localized within the former high-strain zone.The Gini coefficient was used to quantify the degree of strain localization and shows an initial increase during the crack closure phase,a decrease during the linear elastic phase,and a subsequent increase during the post-yielding phase.This behavior corresponds to a process of initial localization from an imperfect boundary condition,homogenization,and eventual relocalization prior to the macroscopic failure of the sample.The transient strain rate decay during the stress relaxation phase was quantified using the p-value in the“Omori-like"power law function.A higher initial stress at the onset of relaxation results in a lower p-value,indicating a slower strain rate decay.As the sample approaches macroscopic failure,the lowest p-value shifts from the most damaged zone to adjacent areas,suggesting stress redistribution or crack propagation in deformed crystalline rocks under stress relaxation conditions.
