Long-period fiber gratings have the advantages of small size,corrosion resistance,anti-electro-magnetic interference,and high sensitivity,making them widely used in biomedicine,the power industry,and aerospace.This pa...Long-period fiber gratings have the advantages of small size,corrosion resistance,anti-electro-magnetic interference,and high sensitivity,making them widely used in biomedicine,the power industry,and aerospace.This paper develops a long-period fiber grating sensor based on periodic microchannels.First,a series of linear structures were etched in the cladding of a single-mode fiber by femtosecond laser microma-chining.Then,the laser-modified region was selectively eroded by selective chemical etching to obtain the periodic microchannel structure.Finally,the channels were filled with polydimethylsiloxane(PDMS)to im-prove the spectral quality.The experimental results show that the sensor has good sensitivity in the measure-ment of various parameters such as temperature,stress,refractive index(RI),and bending.It has a temperat-ure sensitivity of−55.19 pm/℃,a strain sensitivity of−3.19 pm/με,a maximum refractive index sensitivity of 540.28 nm/RIU,and a bending sensitivity of 2.65 dB/m^(-1).All of the measurement parameters show good lin-ear responses.The sensor has strong application prospects in the field of precision measurement and sensing.展开更多
This paper examines the design and optimization of optical fibers for high-speed data transmission, emphasizing advancements that maximize efficiency in modern communication networks. Optical fibers, core components o...This paper examines the design and optimization of optical fibers for high-speed data transmission, emphasizing advancements that maximize efficiency in modern communication networks. Optical fibers, core components of global communication infrastructure, are capable of transmitting data over long distances with minimal loss through principles like total internal reflection. This study explores single-mode and multi-mode fiber designs, providing an overview of key parameters such as core diameter, refractive index profile, and numerical aperture. Mathematical modeling using Maxwell’s equations plays a central role in optimizing fiber performance, helping engineers mitigate challenges like attenuation and dispersion. The paper also discusses advanced techniques, including dense wavelength division multiplexing (DWDM), which enables terabit-per-second data rates. Case studies in practical applications, such as fiber-to-the-home (FTTH) networks and transoceanic cables, highlight the impact of optimized designs on network performance. Looking forward, innovations in photonic crystal fibers and hollow-core fibers are expected to drive further improvements, enabling ultra-high-speed data transmission. The paper concludes by underscoring the significance of continuous research and development to address challenges in optical fiber technology and support the increasing demands of global communication systems.展开更多
Road construction in Africa is faced with a shortage of quality materials, leading to delays and increased costs. Traditional materials, such as clay soils of the bar soil type, have inadequate properties for pavement...Road construction in Africa is faced with a shortage of quality materials, leading to delays and increased costs. Traditional materials, such as clay soils of the bar soil type, have inadequate properties for pavement sub-base layers, particularly in terms of bearing capacity. This study explores a composite material combining bar soil and bamboo fibers to improve the mechanical performance of bar soil, offering a sustainable and cost-effective solution. The Tori-Bossito bar soil was characterised by particle size analysis, Atterberg limits, Proctor compaction tests and the California Bearing Ratio (CBR). The results show that this material is a class A2 sandy-clay soil with a CBR of 18, which is insufficient for foundation layers requiring a CBR of over 30. To improve its performance, Sèmè-Kpodji bamboo fibers, 30 to 100 microns in diameter and 3 to 5 cm long, were incorporated at rates of 0.9% to 2.7%. The optimum mix, with 2.4% fiber, has a CBR of 35, a dry density of 1.92 t/m3 and a moisture content of 12.4%. This reinforced material is suitable as a base course for low-traffic roadways.展开更多
Concrete buildings used in cold regions are prone to freeze-thaw damage, leading to internal cracking and surface peeling of the concrete. Therefore, improving the freeze-thaw resistance of concrete is of great signif...Concrete buildings used in cold regions are prone to freeze-thaw damage, leading to internal cracking and surface peeling of the concrete. Therefore, improving the freeze-thaw resistance of concrete is of great significance for the safety of hydraulic engineering. This paper explores the effect of basalt fibers on improving the frost resistance index of concrete through a series of experiments, and analyzes the influencing mechanism. The results show that adding an appropriate amount of basalt fibers can significantly improve the frost resistance of concrete and reduce the freeze-thaw damage phenomenon indicated by concrete specimens. Adding 0.1% basalt fiber can maintain the relative dynamic modulus of concrete specimens at 98% after 150 freeze-thaw cycles, while adding 0.3% basalt fiber can control the quality loss rate of concrete specimens after 150 freeze-thaw cycles at 0.87%. Taking into account both the frost resistance effect and economic factors, it is recommended that the basalt fiber content in frost resistant concrete be 0.1%. The research results can provide reference and guidance for the optimization design of the mix proportion of hydraulic concrete in cold regions.展开更多
Jute is the golden fiber crop of Bangladesh. Viral and Nemic diseases are the major threats to fiber crops, and the fiber yield decreases drastically as the disease infection increases. An experiment was conducted to ...Jute is the golden fiber crop of Bangladesh. Viral and Nemic diseases are the major threats to fiber crops, and the fiber yield decreases drastically as the disease infection increases. An experiment was conducted to screen and evaluate ten Jute and allied fiber varieties i.e. BJRI Kenaf-4, BJRI Kenaf-3, HS-95 (Kenaf), HS-24 (Mesta pat), HC-2 (Kenaf), BJRI Deshi pat-8, BJRI Deshi pat-7, BJRI Deshi pat-5, BJRI Deshi pat-6 and CVL-1 against mosaic virus and root-knot nematode disease. It was done in RCBD design with three replications at Sher-e-Bangla Agricultural University (SAU) central farm, Dhaka-1207, from June 2018 to March 2019. In the case of viral infection, variety 4 (HS-24 (Mesta pat)) showed maximum virus incidence (23.11%), whereas variety 2 (BJRI Kenaf-3) had no virus evidence. The most susceptible nematode-infected variety was found in varieties 5 (HC-2 (Kenaf)) and 9 (BJRI Deshi pat-6), which showed 80% incidence, whereas variety 2 (BJRI Kenaf-3) was highly resistance. The growth and yield results showed a significant (0.05%) reduction of plant height (cm) and fiber weight (t/ha) with an increase in the percentage of virus and nematode incidence against all varieties. The highest fiber weight (1.47 t/ha) and the lowest viral (0%) and nemic infection (0%) were found in variety 2 (BJRI Kenaf-3), which showed better performance compared to other varieties. These results revealed that variety 2 (BJRI Kenaf-3) had the best variety in the present study.展开更多
Bangladesh’s thriving okra cultivation sector annually yields substantial harvests, yet a significant portion of the plant remains underutilized after harvesting, posing as agricultural waste. This oversight neglects...Bangladesh’s thriving okra cultivation sector annually yields substantial harvests, yet a significant portion of the plant remains underutilized after harvesting, posing as agricultural waste. This oversight neglects the economic potential of okra fiber, which is versatile and valuable across various industries. This paper explores this untapped potential by investigating the physico-mechanical properties, chemical treatments, and fabrication techniques of okra fiber, drawing from a wealth of research. Comparative analyses with established natural fibers like jute and sisal shed light on okra fiber’s transformative role in Bangladesh’s economic landscape. Along with the applications in the fashion world, meticulous investigation into its mechanical, thermal, and morphological characteristics uncovers inherent strengths and integration pathways into industrial applications. Strategies for optimizing yield and quality, including novel approaches like photo-grafting and protein extraction, are explored. Considerations for cytotoxicity and environmental sustainability ensure its viability as a green resource. This research aims to unlock okra fiber’s full potential, positioning Bangladesh for sustainable economic development and innovation.展开更多
Niobates are promising all-climate Li^(+)-storage anode material due to their fast charge transport,large specific capacities,and resistance to electrolyte reaction.However,their moderate unit-cellvolume expansion(gen...Niobates are promising all-climate Li^(+)-storage anode material due to their fast charge transport,large specific capacities,and resistance to electrolyte reaction.However,their moderate unit-cellvolume expansion(generally 5%–10%)during Li^(+)storage causes unsatisfactory long-term cyclability.Here,“zero-strain”NiNb_(2)O_(6) fibers are explored as a new anode material with comprehensively good electrochemical properties.During Li^(+)storage,the expansion of electrochemical inactive NiO_(6) octahedra almost fully offsets the shrinkage of active NbO_(6) octahedra through reversible O movement.Such superior volume-accommodation capability of the NiO_(6) layers guarantees the“zero-strain”behavior of NiNb_(2)O_(6) in a broad temperature range(0.53%//0.51%//0.74%at 25//−10//60℃),leading to the excellent cyclability of the NiNb_(2)O_(6) fibers(92.8%//99.2%//91.1%capacity retention after 1000//2000//1000 cycles at 10C and 25//−10//60℃).This NiNb_(2)O_(6) material further exhibits a large reversible capacity(300//184//318 mAh g−1 at 0.1C and 25//−10//60℃)and outstanding rate performance(10 to 0.5C capacity percentage of 64.3%//50.0%//65.4%at 25//−10//60℃).Therefore,the NiNb_(2)O_(6) fibers are especially suitable for large-capacity,fast-charging,long-life,and all-climate lithium-ion batteries.展开更多
Silica fibers were modified by a specific ratio of SiB6 mixed with silica sol through vacuum impregnation method.The modified fibers were then incorporated into a phenolic resin matrix to prepare fiber-reinforced resi...Silica fibers were modified by a specific ratio of SiB6 mixed with silica sol through vacuum impregnation method.The modified fibers were then incorporated into a phenolic resin matrix to prepare fiber-reinforced resin composites.The influences of the SiB_(6)/SiO_(2)mixed modification on silica fiber properties were analyzed through thermogravimetric analysis(TGA),differential scanning calorimetry(DSC),scanning electron microscopy(SEM),and X-ray diffraction(XRD),respectively.Additionally,the influence of the SiB_(6)/SiO_(2)mixed modification on the mechanical properties of phenolic resin matrix composites was evaluated through mechanical testing.The experimeatal results indicate that the SiB_(6)/SiO_(2)mixed surface modification shows significant improvement in strength at room temperature and high temperatures,and crystallization temperature of silica fiber increases.The SiB_(6)/Silica sol co-modified silica fiber shows potential for future application in thermal protection and other high-temperature conditions.展开更多
This study focuses on the thermophysical characterizations of composite materials made from polypropylene reinforced with residues and fibers from Borassus wood from Chad. These properties are experimentally determine...This study focuses on the thermophysical characterizations of composite materials made from polypropylene reinforced with residues and fibers from Borassus wood from Chad. These properties are experimentally determined at different temperatures using the hot wire method of the “FP2C” machine, where the hot wire probe is inserted between two specimens. The values of the thermal conductivity in powdered Borassus wood range from 0.170 W/mK to 0.182 W/mK for female wood (FNTF) and from 0.169 W/mK to 0.173 W/mK for male wood. For the female and male fibers, the thermal conductivity values range from 0.137 W/mK to 0.157 W/mK for the female and from 0.138 W/mK to 0.168 W/mK for the male. The thermal effusivity of the residues and fibers of Borassus wood varies from: 509.6 Ws1/2/m2K to 543 Ws1/2/m2K for the powder of female wood and from 524.6 Ws1/2/m2K to 547 Ws1/2/m2K for the powder of male wood. For the fibers of Borassus wood, the values range from 410.6 Ws1/2/m2K to 523.6 Ws1/2/m2K for the female wood fibers and from 420.3 Ws1/2/m2K to 480.3 Ws1/2/m2K for the male wood fibers. These results are important for the applications of Borassus wood residues and fibers in construction works regarding the thermal insulation of habitats.展开更多
This study investigates the compressive and tensile properties of basalt fiber-reinforced concrete (BFRC) after ultra-low-temperature freeze-thaw cycles. Scanning electron microscope (SEM) analysis was conducted to ex...This study investigates the compressive and tensile properties of basalt fiber-reinforced concrete (BFRC) after ultra-low-temperature freeze-thaw cycles. Scanning electron microscope (SEM) analysis was conducted to examine the deterioration mechanisms caused by freeze-thaw cycles and sulfate erosion. The results show that compressive and tensile strengths increase with basalt fiber dosage. The optimal dosage is 0.2%. With longer exposure to sulfate erosion, both strengths decline significantly. Basalt fibers effectively bridge cracks, control expansion, enhance compactness, and improve concrete performance. Ultra-low-temperature freeze-thaw cycles and sulfate erosion cause rapid crack growth. Sulfate erosion produces crystallization products and expansive substances. These fill cracks, create pressure, and damage the internal structure. Freezing and expansion forces further enlarge voids and cracks. This provides space for expansive substances, worsening concrete deterioration and reducing its performance.展开更多
Iced transmission line galloping poses a significant threat to the safety and reliability of power systems,leading directly to line tripping,disconnections,and power outages.Existing early warning methods of iced tran...Iced transmission line galloping poses a significant threat to the safety and reliability of power systems,leading directly to line tripping,disconnections,and power outages.Existing early warning methods of iced transmission line galloping suffer from issues such as reliance on a single data source,neglect of irregular time series,and lack of attention-based closed-loop feedback,resulting in high rates of missed and false alarms.To address these challenges,we propose an Internet of Things(IoT)empowered early warning method of transmission line galloping that integrates time series data from optical fiber sensing and weather forecast.Initially,the method applies a primary adaptive weighted fusion to the IoT empowered optical fiber real-time sensing data and weather forecast data,followed by a secondary fusion based on a Back Propagation(BP)neural network,and uses the K-medoids algorithm for clustering the fused data.Furthermore,an adaptive irregular time series perception adjustment module is introduced into the traditional Gated Recurrent Unit(GRU)network,and closed-loop feedback based on attentionmechanism is employed to update network parameters through gradient feedback of the loss function,enabling closed-loop training and time series data prediction of the GRU network model.Subsequently,considering various types of prediction data and the duration of icing,an iced transmission line galloping risk coefficient is established,and warnings are categorized based on this coefficient.Finally,using an IoT-driven realistic dataset of iced transmission line galloping,the effectiveness of the proposed method is validated through multi-dimensional simulation scenarios.展开更多
The life-history strategies of organisms are shaped by trade-offs among traits that influence survival,development,reproduction,and ultimately fitness.However,the specific physiological and environmental mechanisms dr...The life-history strategies of organisms are shaped by trade-offs among traits that influence survival,development,reproduction,and ultimately fitness.However,the specific physiological and environmental mechanisms driving population-level variation in phenotypic traits,particularly in relation to migratory adaptations,remain poorly understood.Elevational migration represents an adaptive behavior for mountain birds that offers a unique model to investigate adaptive phenotypes because of the diverse migratory strategies that have been observed within and between species.Flight muscles,as multifunctional organs,exhibit phenotypic variation that aligns with locomotor and thermoregulatory demands.Linking flight muscle phenotypes to migratory strategies can provide insights into inter-and intraspecific variation in migratory adaptations.In this study,we examined spring arrival dates at high-altitude breeding sites for three closely related high-altitude breeding birds in the mountains of Asia:Blue-fronted Redstart(Phoenicurus frontalis),Himalayan Bluetail(Tarsiger rufilatus),and Rufous-gorgeted Flycatcher(Ficedula strophiata).We analyzed relationships between arrival dates and phenotypic traits,including flight muscle physiology,morphology,and internal organ mass,alongside environmental effects on these traits.Our findings indicate that species arriving earlier encountered lower temperatures and exhibited reduced fiber cross-sectional areas coupled with higher fast oxidative glycolytic(FOG)fibers densities.Males displayed pronounced protandry and higher fast glycolytic(FG)fibers densities.Ambient temperature significantly influenced flight muscle phenotypes,highlighting intraspecific variation and the potential plasticity of flight muscle fibers as crucial mechanisms for adapting to migration strategies and environmental conditions.Additionally,this study underscores the potential role of sexual selection in shaping functional phenotypic variation,further advancing our understanding of adaptive strategies in high-altitude migratory birds.展开更多
Vibration-induced bias deviation,which is generated by intensity fluctuations and additional phase differences,is one of the vital errors for fiber optic gyroscopes(FOGs)operating in vibration environment and has seve...Vibration-induced bias deviation,which is generated by intensity fluctuations and additional phase differences,is one of the vital errors for fiber optic gyroscopes(FOGs)operating in vibration environment and has severely restricted the applications of high-precision FOGs.The conventional methods for suppressing vibration-induced errors mostly concentrate on reinforcing the mechanical structure and optical path as well as the compensation under some specific operation parameters,which have very limited effects for high-precision FOGs maintaining performances under vibration.In this work,a technique of suppressing the vibration-induced bias deviation through removing the part related to the varying gain from the rotation-rate output is put forward.Particularly,the loop gain is extracted out by adding a gain-monitoring wave.By demodulating the loop gain and the rotation rate simultaneously under distinct frequencies and investigating their quantitative relationship,the vibrationinduced bias error is compensated without limiting the operating parameters or environments,like the applied modulation depth.The experimental results show that the proposed method has achieved the reduction of bias error from about 0.149°/h to0.014°/h during the random vibration with frequencies from20 Hz to 2000 Hz.This technique provides a feasible route for enhancing the performances of high-precision FOGs heading towards high environmental adaptability.展开更多
Introducing the inherent genetic diversity of wild species into cultivars has become one of the hot topics in crop genetic breeding and genetic resource research.Fiber-and seed-related traits,which are critical to the...Introducing the inherent genetic diversity of wild species into cultivars has become one of the hot topics in crop genetic breeding and genetic resource research.Fiber-and seed-related traits,which are critical to the global economy and people's livelihoods,are the principal focus of cotton breeding.Here,the wild cotton species Gossypium tomentosum was used to broaden the genetic basis of G.hirsutum and identify QTLs for fiber-and seed-related traits.A population of 559 chromosome segment substitution lines(CSSLs)was established with various chromosome segments from G.tomentosum in a G.hirsutum cultivar background.Totals of 72,89,and 76 QTLs were identified for three yield traits,five fiber quality traits,and six cottonseed nutrient quality traits,respectively.Favorable alleles of 104 QTLs were contributed by G.tomentosum.Sixty-four QTLs were identified in two or more environments,and candidate genes for three of them were further identified.The results of this study contribute to further studies on the genetic basis of the morphogenesis of these economic traits,and indicate the great breeding potential of G.tomentosum for improving the fiber-and seed-related traits in G.hirsutum.展开更多
In this paper,a double-effect DNN-based Digital Back-Propagation(DBP)scheme is proposed and studied to achieve the Integrated Communication and Sensing(ICS)ability,which can not only realize nonlinear damage mitigatio...In this paper,a double-effect DNN-based Digital Back-Propagation(DBP)scheme is proposed and studied to achieve the Integrated Communication and Sensing(ICS)ability,which can not only realize nonlinear damage mitigation but also monitor the optical power and dispersion profile over multi-span links.The link status information can be extracted by the characteristics of the learned optical fiber parameters without any other measuring instruments.The efficiency and feasibility of this method have been investigated in different fiber link conditions,including various launch power,transmission distance,and the location and the amount of the abnormal losses.A good monitoring performance can be obtained while the launch optical power is 2 dBm which does not affect the normal operation of the optical communication system and the step size of DBP is 20 km which can provide a better distance resolution.This scheme successfully detects the location of single or multiple optical attenuators in long-distance multi-span fiber links,including different abnormal losses of 2 dB,4 dB,and 6 dB in 360 km and serval combinations of abnormal losses of(1 dB,5 dB),(3 dB,3 dB),(5 dB,1 dB)in 360 km and 760 km.Meanwhile,the transfer relationship of the estimated coefficient values with different step sizes is further investigated to reduce the complexity of the fiber nonlinear damage compensation.These results provide an attractive approach for precisely sensing the optical fiber link status information and making correct strategies timely to ensure optical communication system operations.展开更多
Objective:To observe the changes of peripapillary vascular density(VD)and its correlation with retinal nerve fiber layer(RNFL)thickness in patients with unilateral retinal vein occlusion(RVO)by optical coherence tomog...Objective:To observe the changes of peripapillary vascular density(VD)and its correlation with retinal nerve fiber layer(RNFL)thickness in patients with unilateral retinal vein occlusion(RVO)by optical coherence tomography angiography(OCTA).Methods:Prospective case-control study.Thirty-two patients(32 eyes)with RVO diagnosed at the Eye Hospital of China Academy of Chinese Medical Sciences from September 2020 to June 2021 were selected.Another 32 outpatients(32 eyes)with normal ocular examination were selected as the normal control group.Optic disc blood flow imaging was performed in all subjects using the OCTA to measure peripapillary RNFL thickness,peripapillary vessel density,optic disc area,and disc rim area.The correlation between peripapillary vascular density and RNFL,optic disc area and disc rim area in eyes with unilateral RVO was analyzed.Results:Compared with the normal control group,the prevalence of hypertension was higher in the unilateral RVO group,and the difference was statistically significant(P<0.05).Compared with the normal control group,the overall,inferior and temporal RNFL thickness around the optic disc was thinner in patients with unilateral RVO,and the difference was statistically significant(P<005).Compared with the normal control group,the overall VD,internal ring,external ring and inferior VD around the optic disc were slightly decreased in patients with unilateral RVO,and the differences were statistically significant(P<0.05).The results of Pearson correlation analysis indicated that RNFL thickness was positively correlated with peripapillary global VD(r=0.648,P<0.001),RNFL thickness was positively correlated with intrapapillary ring VD(r=0.427,P=0.015),and RNFL thickness was positively correlated with peripapillary VD(r=0.666,P<0.001).Conclusion:The results showed that the RNFL thickness around the optic disc was thinner in patients with unilateral RVO,especially in the inferior and temporal area,and the full area VD around the optic disc was decreased,especially in the internal ring,external ring and inferior area.In patients with unilateral RVO,peripapillary RNFL was positively correlated with peripapillary global,internal ring and external ring VD.展开更多
Cotton is one of the most important economic crops in the world,and it is a major source of fiber in the textile industry.Strigolactones(SLs)are a class of carotenoid-derived plant hormones involved in many processes ...Cotton is one of the most important economic crops in the world,and it is a major source of fiber in the textile industry.Strigolactones(SLs)are a class of carotenoid-derived plant hormones involved in many processes of plant growth and development,although the functions of SL in fiber development remain largely unknown.Here,we found that the endogenous SLs were significantly higher in fibers at 20 days post-anthesis(DPA).Exogenous SLs significantly increased fiber length and cell wall thickness.Furthermore,we cloned three key SL biosynthetic genes,namely GhD27,GhMAX3,and GhMAX4,which were highly expressed in fibers,and subcellular localization analyses revealed that GhD27,GhMAX3,and GhMAX4 were localized in the chloroplast.The exogenous expression of GhD27,GhMAX3,and GhMAX4 complemented the physiological phenotypes of d27,max3,and max4 mutations in Arabidopsis,respectively.Knockdown of GhD27,GhMAX3,and GhMAX4 in cotton resulted in increased numbers of axillary buds and leaves,reduced fiber length,and significantly reduced fiber thickness.These findings revealed that SLs participate in plant growth,fiber elongation,and secondary cell wall formation in cotton.These results provide new and effective genetic resources for improving cotton fiber yield and plant architecture.展开更多
BACKGROUND Type 2 diabetes is a chronic,non-communicable disease with a substantial global impact,affecting a significant number of individuals.Its etiology is closely tied to imbalanced dietary practices and sedentar...BACKGROUND Type 2 diabetes is a chronic,non-communicable disease with a substantial global impact,affecting a significant number of individuals.Its etiology is closely tied to imbalanced dietary practices and sedentary lifestyles.Conversely,increasing die-tary fiber(DF)intake has consistently demonstrated health benefits in numerous studies,including improvements in glycemic control and weight management.AIM To investigate the efficacy of DF interventions in the management of type 2 diabetes mellitus(T2DM).METHODS A systematic literature review was conducted to explore the association between DF intake and the management of T2DM.Following the inclusion and exclusion criteria,a total of 26 studies were included in this review.RESULTS The main strategies implied to increased DF intake were:High DF diet plus acarbose(2 studies);DF supplements(14 studies);and high DF diets(10 studies).Overall,most studies indicated that increased DF intake resulted in im-provements in glycemic control and weight management in T2DM patients.CONCLUSION DF represents a valuable strategy in the treatment of type 2 diabetes,improving health outcomes.DF intake offers the potential to improve quality of life and reduce complications and mortality associated with diabetes.Likewise,through supplements or enriched foods,DF contributes significantly to the control of several markers such as HbA1c,blood glucose,triglycerides,low-density lipoprotein,and body weight.展开更多
Side-by-side bicomponent fibers have a spring-like three-dimensional spiral crimp structure and are widely used in elastic fabric.The difference in thermal shrinkage between different polymers can produce an unbalance...Side-by-side bicomponent fibers have a spring-like three-dimensional spiral crimp structure and are widely used in elastic fabric.The difference in thermal shrinkage between different polymers can produce an unbalanced stress during the cooling process,and this unbalanced stress can be exploited to prepare naturally crimped fibers by spinning design.In this work,different types of polyamides(PAs)were selected for fabrication of the PA-based side-by-side bicomponent elastic fibers using melt spinning,and the structure development and performance of such bicomponent elastic fibers were studied.Meanwhile,thermoplastic PA elastomer(TPAE)with intrinsic elasticity was also used as one of the comparative materials.The block structure of the PA segment and the polyether segment in the TPAE molecule is the key to providing thermal shrinkage differences and forming a good interface structure.As a result,the crimp ratio of PA6/TPAE bicomponent elastic fiber is 7.23%,which is better than that of the currently commercialized T400 fiber(6.72%).The excellent crimp performance of PA6/TPAE bicomponent elastic fibers comes from the asymmetric distribution of the stress along the radial direction of the fibers during the cooling process,which is caused by the difference in thermal shrinkage between PA6 and TPAE.In addition,the crimp formability of the PA-based bicomponent elastic fibers could be improved by expanding the shrinkage stress through wet-heat treatment.The crimp ratio of PA6/TPAE bicomponent elastic fibers reaches the maximum(33.08%)after treatment at 100℃.At the same time,the fabric made of PA6/TPAE bicomponent elastic fibers has the excellent air and water vapor permeability,with an air permeability of 272.76 mm/s and a water vapor transmission rate of 406.71 g/(m^(2)·h).展开更多
文摘Long-period fiber gratings have the advantages of small size,corrosion resistance,anti-electro-magnetic interference,and high sensitivity,making them widely used in biomedicine,the power industry,and aerospace.This paper develops a long-period fiber grating sensor based on periodic microchannels.First,a series of linear structures were etched in the cladding of a single-mode fiber by femtosecond laser microma-chining.Then,the laser-modified region was selectively eroded by selective chemical etching to obtain the periodic microchannel structure.Finally,the channels were filled with polydimethylsiloxane(PDMS)to im-prove the spectral quality.The experimental results show that the sensor has good sensitivity in the measure-ment of various parameters such as temperature,stress,refractive index(RI),and bending.It has a temperat-ure sensitivity of−55.19 pm/℃,a strain sensitivity of−3.19 pm/με,a maximum refractive index sensitivity of 540.28 nm/RIU,and a bending sensitivity of 2.65 dB/m^(-1).All of the measurement parameters show good lin-ear responses.The sensor has strong application prospects in the field of precision measurement and sensing.
文摘This paper examines the design and optimization of optical fibers for high-speed data transmission, emphasizing advancements that maximize efficiency in modern communication networks. Optical fibers, core components of global communication infrastructure, are capable of transmitting data over long distances with minimal loss through principles like total internal reflection. This study explores single-mode and multi-mode fiber designs, providing an overview of key parameters such as core diameter, refractive index profile, and numerical aperture. Mathematical modeling using Maxwell’s equations plays a central role in optimizing fiber performance, helping engineers mitigate challenges like attenuation and dispersion. The paper also discusses advanced techniques, including dense wavelength division multiplexing (DWDM), which enables terabit-per-second data rates. Case studies in practical applications, such as fiber-to-the-home (FTTH) networks and transoceanic cables, highlight the impact of optimized designs on network performance. Looking forward, innovations in photonic crystal fibers and hollow-core fibers are expected to drive further improvements, enabling ultra-high-speed data transmission. The paper concludes by underscoring the significance of continuous research and development to address challenges in optical fiber technology and support the increasing demands of global communication systems.
文摘Road construction in Africa is faced with a shortage of quality materials, leading to delays and increased costs. Traditional materials, such as clay soils of the bar soil type, have inadequate properties for pavement sub-base layers, particularly in terms of bearing capacity. This study explores a composite material combining bar soil and bamboo fibers to improve the mechanical performance of bar soil, offering a sustainable and cost-effective solution. The Tori-Bossito bar soil was characterised by particle size analysis, Atterberg limits, Proctor compaction tests and the California Bearing Ratio (CBR). The results show that this material is a class A2 sandy-clay soil with a CBR of 18, which is insufficient for foundation layers requiring a CBR of over 30. To improve its performance, Sèmè-Kpodji bamboo fibers, 30 to 100 microns in diameter and 3 to 5 cm long, were incorporated at rates of 0.9% to 2.7%. The optimum mix, with 2.4% fiber, has a CBR of 35, a dry density of 1.92 t/m3 and a moisture content of 12.4%. This reinforced material is suitable as a base course for low-traffic roadways.
文摘Concrete buildings used in cold regions are prone to freeze-thaw damage, leading to internal cracking and surface peeling of the concrete. Therefore, improving the freeze-thaw resistance of concrete is of great significance for the safety of hydraulic engineering. This paper explores the effect of basalt fibers on improving the frost resistance index of concrete through a series of experiments, and analyzes the influencing mechanism. The results show that adding an appropriate amount of basalt fibers can significantly improve the frost resistance of concrete and reduce the freeze-thaw damage phenomenon indicated by concrete specimens. Adding 0.1% basalt fiber can maintain the relative dynamic modulus of concrete specimens at 98% after 150 freeze-thaw cycles, while adding 0.3% basalt fiber can control the quality loss rate of concrete specimens after 150 freeze-thaw cycles at 0.87%. Taking into account both the frost resistance effect and economic factors, it is recommended that the basalt fiber content in frost resistant concrete be 0.1%. The research results can provide reference and guidance for the optimization design of the mix proportion of hydraulic concrete in cold regions.
文摘Jute is the golden fiber crop of Bangladesh. Viral and Nemic diseases are the major threats to fiber crops, and the fiber yield decreases drastically as the disease infection increases. An experiment was conducted to screen and evaluate ten Jute and allied fiber varieties i.e. BJRI Kenaf-4, BJRI Kenaf-3, HS-95 (Kenaf), HS-24 (Mesta pat), HC-2 (Kenaf), BJRI Deshi pat-8, BJRI Deshi pat-7, BJRI Deshi pat-5, BJRI Deshi pat-6 and CVL-1 against mosaic virus and root-knot nematode disease. It was done in RCBD design with three replications at Sher-e-Bangla Agricultural University (SAU) central farm, Dhaka-1207, from June 2018 to March 2019. In the case of viral infection, variety 4 (HS-24 (Mesta pat)) showed maximum virus incidence (23.11%), whereas variety 2 (BJRI Kenaf-3) had no virus evidence. The most susceptible nematode-infected variety was found in varieties 5 (HC-2 (Kenaf)) and 9 (BJRI Deshi pat-6), which showed 80% incidence, whereas variety 2 (BJRI Kenaf-3) was highly resistance. The growth and yield results showed a significant (0.05%) reduction of plant height (cm) and fiber weight (t/ha) with an increase in the percentage of virus and nematode incidence against all varieties. The highest fiber weight (1.47 t/ha) and the lowest viral (0%) and nemic infection (0%) were found in variety 2 (BJRI Kenaf-3), which showed better performance compared to other varieties. These results revealed that variety 2 (BJRI Kenaf-3) had the best variety in the present study.
文摘Bangladesh’s thriving okra cultivation sector annually yields substantial harvests, yet a significant portion of the plant remains underutilized after harvesting, posing as agricultural waste. This oversight neglects the economic potential of okra fiber, which is versatile and valuable across various industries. This paper explores this untapped potential by investigating the physico-mechanical properties, chemical treatments, and fabrication techniques of okra fiber, drawing from a wealth of research. Comparative analyses with established natural fibers like jute and sisal shed light on okra fiber’s transformative role in Bangladesh’s economic landscape. Along with the applications in the fashion world, meticulous investigation into its mechanical, thermal, and morphological characteristics uncovers inherent strengths and integration pathways into industrial applications. Strategies for optimizing yield and quality, including novel approaches like photo-grafting and protein extraction, are explored. Considerations for cytotoxicity and environmental sustainability ensure its viability as a green resource. This research aims to unlock okra fiber’s full potential, positioning Bangladesh for sustainable economic development and innovation.
基金supported by the National Natural Science Foundation of China(51762014,52231007,12327804,T2321003,22088101)in part by the National Key Research Program of China under Grant 2021YFA1200600.
文摘Niobates are promising all-climate Li^(+)-storage anode material due to their fast charge transport,large specific capacities,and resistance to electrolyte reaction.However,their moderate unit-cellvolume expansion(generally 5%–10%)during Li^(+)storage causes unsatisfactory long-term cyclability.Here,“zero-strain”NiNb_(2)O_(6) fibers are explored as a new anode material with comprehensively good electrochemical properties.During Li^(+)storage,the expansion of electrochemical inactive NiO_(6) octahedra almost fully offsets the shrinkage of active NbO_(6) octahedra through reversible O movement.Such superior volume-accommodation capability of the NiO_(6) layers guarantees the“zero-strain”behavior of NiNb_(2)O_(6) in a broad temperature range(0.53%//0.51%//0.74%at 25//−10//60℃),leading to the excellent cyclability of the NiNb_(2)O_(6) fibers(92.8%//99.2%//91.1%capacity retention after 1000//2000//1000 cycles at 10C and 25//−10//60℃).This NiNb_(2)O_(6) material further exhibits a large reversible capacity(300//184//318 mAh g−1 at 0.1C and 25//−10//60℃)and outstanding rate performance(10 to 0.5C capacity percentage of 64.3%//50.0%//65.4%at 25//−10//60℃).Therefore,the NiNb_(2)O_(6) fibers are especially suitable for large-capacity,fast-charging,long-life,and all-climate lithium-ion batteries.
基金Funded by the Natural Science Foundation of Hubei Province(No.2024AFB833)。
文摘Silica fibers were modified by a specific ratio of SiB6 mixed with silica sol through vacuum impregnation method.The modified fibers were then incorporated into a phenolic resin matrix to prepare fiber-reinforced resin composites.The influences of the SiB_(6)/SiO_(2)mixed modification on silica fiber properties were analyzed through thermogravimetric analysis(TGA),differential scanning calorimetry(DSC),scanning electron microscopy(SEM),and X-ray diffraction(XRD),respectively.Additionally,the influence of the SiB_(6)/SiO_(2)mixed modification on the mechanical properties of phenolic resin matrix composites was evaluated through mechanical testing.The experimeatal results indicate that the SiB_(6)/SiO_(2)mixed surface modification shows significant improvement in strength at room temperature and high temperatures,and crystallization temperature of silica fiber increases.The SiB_(6)/Silica sol co-modified silica fiber shows potential for future application in thermal protection and other high-temperature conditions.
文摘This study focuses on the thermophysical characterizations of composite materials made from polypropylene reinforced with residues and fibers from Borassus wood from Chad. These properties are experimentally determined at different temperatures using the hot wire method of the “FP2C” machine, where the hot wire probe is inserted between two specimens. The values of the thermal conductivity in powdered Borassus wood range from 0.170 W/mK to 0.182 W/mK for female wood (FNTF) and from 0.169 W/mK to 0.173 W/mK for male wood. For the female and male fibers, the thermal conductivity values range from 0.137 W/mK to 0.157 W/mK for the female and from 0.138 W/mK to 0.168 W/mK for the male. The thermal effusivity of the residues and fibers of Borassus wood varies from: 509.6 Ws1/2/m2K to 543 Ws1/2/m2K for the powder of female wood and from 524.6 Ws1/2/m2K to 547 Ws1/2/m2K for the powder of male wood. For the fibers of Borassus wood, the values range from 410.6 Ws1/2/m2K to 523.6 Ws1/2/m2K for the female wood fibers and from 420.3 Ws1/2/m2K to 480.3 Ws1/2/m2K for the male wood fibers. These results are important for the applications of Borassus wood residues and fibers in construction works regarding the thermal insulation of habitats.
文摘This study investigates the compressive and tensile properties of basalt fiber-reinforced concrete (BFRC) after ultra-low-temperature freeze-thaw cycles. Scanning electron microscope (SEM) analysis was conducted to examine the deterioration mechanisms caused by freeze-thaw cycles and sulfate erosion. The results show that compressive and tensile strengths increase with basalt fiber dosage. The optimal dosage is 0.2%. With longer exposure to sulfate erosion, both strengths decline significantly. Basalt fibers effectively bridge cracks, control expansion, enhance compactness, and improve concrete performance. Ultra-low-temperature freeze-thaw cycles and sulfate erosion cause rapid crack growth. Sulfate erosion produces crystallization products and expansive substances. These fill cracks, create pressure, and damage the internal structure. Freezing and expansion forces further enlarge voids and cracks. This provides space for expansive substances, worsening concrete deterioration and reducing its performance.
基金research was funded by Science and Technology Project of State Grid Corporation of China under grant number 5200-202319382A-2-3-XG.
文摘Iced transmission line galloping poses a significant threat to the safety and reliability of power systems,leading directly to line tripping,disconnections,and power outages.Existing early warning methods of iced transmission line galloping suffer from issues such as reliance on a single data source,neglect of irregular time series,and lack of attention-based closed-loop feedback,resulting in high rates of missed and false alarms.To address these challenges,we propose an Internet of Things(IoT)empowered early warning method of transmission line galloping that integrates time series data from optical fiber sensing and weather forecast.Initially,the method applies a primary adaptive weighted fusion to the IoT empowered optical fiber real-time sensing data and weather forecast data,followed by a secondary fusion based on a Back Propagation(BP)neural network,and uses the K-medoids algorithm for clustering the fused data.Furthermore,an adaptive irregular time series perception adjustment module is introduced into the traditional Gated Recurrent Unit(GRU)network,and closed-loop feedback based on attentionmechanism is employed to update network parameters through gradient feedback of the loss function,enabling closed-loop training and time series data prediction of the GRU network model.Subsequently,considering various types of prediction data and the duration of icing,an iced transmission line galloping risk coefficient is established,and warnings are categorized based on this coefficient.Finally,using an IoT-driven realistic dataset of iced transmission line galloping,the effectiveness of the proposed method is validated through multi-dimensional simulation scenarios.
基金financially supported by the National Natural Science Foundation of China (No.32270454)by the Survey of Wildlife Resources in Key Areas of Tibet (ZL202203601)。
文摘The life-history strategies of organisms are shaped by trade-offs among traits that influence survival,development,reproduction,and ultimately fitness.However,the specific physiological and environmental mechanisms driving population-level variation in phenotypic traits,particularly in relation to migratory adaptations,remain poorly understood.Elevational migration represents an adaptive behavior for mountain birds that offers a unique model to investigate adaptive phenotypes because of the diverse migratory strategies that have been observed within and between species.Flight muscles,as multifunctional organs,exhibit phenotypic variation that aligns with locomotor and thermoregulatory demands.Linking flight muscle phenotypes to migratory strategies can provide insights into inter-and intraspecific variation in migratory adaptations.In this study,we examined spring arrival dates at high-altitude breeding sites for three closely related high-altitude breeding birds in the mountains of Asia:Blue-fronted Redstart(Phoenicurus frontalis),Himalayan Bluetail(Tarsiger rufilatus),and Rufous-gorgeted Flycatcher(Ficedula strophiata).We analyzed relationships between arrival dates and phenotypic traits,including flight muscle physiology,morphology,and internal organ mass,alongside environmental effects on these traits.Our findings indicate that species arriving earlier encountered lower temperatures and exhibited reduced fiber cross-sectional areas coupled with higher fast oxidative glycolytic(FOG)fibers densities.Males displayed pronounced protandry and higher fast glycolytic(FG)fibers densities.Ambient temperature significantly influenced flight muscle phenotypes,highlighting intraspecific variation and the potential plasticity of flight muscle fibers as crucial mechanisms for adapting to migration strategies and environmental conditions.Additionally,this study underscores the potential role of sexual selection in shaping functional phenotypic variation,further advancing our understanding of adaptive strategies in high-altitude migratory birds.
基金Fundamental Research Funds for the Central Universities(YWF-23-L-1225)National Natural Science Foundation of China(62201025)Chinese Aeronautical Establishment(2022Z037051001)。
文摘Vibration-induced bias deviation,which is generated by intensity fluctuations and additional phase differences,is one of the vital errors for fiber optic gyroscopes(FOGs)operating in vibration environment and has severely restricted the applications of high-precision FOGs.The conventional methods for suppressing vibration-induced errors mostly concentrate on reinforcing the mechanical structure and optical path as well as the compensation under some specific operation parameters,which have very limited effects for high-precision FOGs maintaining performances under vibration.In this work,a technique of suppressing the vibration-induced bias deviation through removing the part related to the varying gain from the rotation-rate output is put forward.Particularly,the loop gain is extracted out by adding a gain-monitoring wave.By demodulating the loop gain and the rotation rate simultaneously under distinct frequencies and investigating their quantitative relationship,the vibrationinduced bias error is compensated without limiting the operating parameters or environments,like the applied modulation depth.The experimental results show that the proposed method has achieved the reduction of bias error from about 0.149°/h to0.014°/h during the random vibration with frequencies from20 Hz to 2000 Hz.This technique provides a feasible route for enhancing the performances of high-precision FOGs heading towards high environmental adaptability.
基金supported by the National Natural Science Foundation of China(32172064)。
文摘Introducing the inherent genetic diversity of wild species into cultivars has become one of the hot topics in crop genetic breeding and genetic resource research.Fiber-and seed-related traits,which are critical to the global economy and people's livelihoods,are the principal focus of cotton breeding.Here,the wild cotton species Gossypium tomentosum was used to broaden the genetic basis of G.hirsutum and identify QTLs for fiber-and seed-related traits.A population of 559 chromosome segment substitution lines(CSSLs)was established with various chromosome segments from G.tomentosum in a G.hirsutum cultivar background.Totals of 72,89,and 76 QTLs were identified for three yield traits,five fiber quality traits,and six cottonseed nutrient quality traits,respectively.Favorable alleles of 104 QTLs were contributed by G.tomentosum.Sixty-four QTLs were identified in two or more environments,and candidate genes for three of them were further identified.The results of this study contribute to further studies on the genetic basis of the morphogenesis of these economic traits,and indicate the great breeding potential of G.tomentosum for improving the fiber-and seed-related traits in G.hirsutum.
基金supported by the National Key Research and Development Program of China (2019YFB1803905)the National Natural Science Foundation of China (No.62171022)+2 种基金Beijing Natural Science Foundation (4222009)Guangdong Basic and Applied Basic Research Foundation (2021B1515120057)the Scientific and Technological Innovation Foundation of Shunde Graduate School,USTB (No.BK19AF005)。
文摘In this paper,a double-effect DNN-based Digital Back-Propagation(DBP)scheme is proposed and studied to achieve the Integrated Communication and Sensing(ICS)ability,which can not only realize nonlinear damage mitigation but also monitor the optical power and dispersion profile over multi-span links.The link status information can be extracted by the characteristics of the learned optical fiber parameters without any other measuring instruments.The efficiency and feasibility of this method have been investigated in different fiber link conditions,including various launch power,transmission distance,and the location and the amount of the abnormal losses.A good monitoring performance can be obtained while the launch optical power is 2 dBm which does not affect the normal operation of the optical communication system and the step size of DBP is 20 km which can provide a better distance resolution.This scheme successfully detects the location of single or multiple optical attenuators in long-distance multi-span fiber links,including different abnormal losses of 2 dB,4 dB,and 6 dB in 360 km and serval combinations of abnormal losses of(1 dB,5 dB),(3 dB,3 dB),(5 dB,1 dB)in 360 km and 760 km.Meanwhile,the transfer relationship of the estimated coefficient values with different step sizes is further investigated to reduce the complexity of the fiber nonlinear damage compensation.These results provide an attractive approach for precisely sensing the optical fiber link status information and making correct strategies timely to ensure optical communication system operations.
文摘Objective:To observe the changes of peripapillary vascular density(VD)and its correlation with retinal nerve fiber layer(RNFL)thickness in patients with unilateral retinal vein occlusion(RVO)by optical coherence tomography angiography(OCTA).Methods:Prospective case-control study.Thirty-two patients(32 eyes)with RVO diagnosed at the Eye Hospital of China Academy of Chinese Medical Sciences from September 2020 to June 2021 were selected.Another 32 outpatients(32 eyes)with normal ocular examination were selected as the normal control group.Optic disc blood flow imaging was performed in all subjects using the OCTA to measure peripapillary RNFL thickness,peripapillary vessel density,optic disc area,and disc rim area.The correlation between peripapillary vascular density and RNFL,optic disc area and disc rim area in eyes with unilateral RVO was analyzed.Results:Compared with the normal control group,the prevalence of hypertension was higher in the unilateral RVO group,and the difference was statistically significant(P<0.05).Compared with the normal control group,the overall,inferior and temporal RNFL thickness around the optic disc was thinner in patients with unilateral RVO,and the difference was statistically significant(P<005).Compared with the normal control group,the overall VD,internal ring,external ring and inferior VD around the optic disc were slightly decreased in patients with unilateral RVO,and the differences were statistically significant(P<0.05).The results of Pearson correlation analysis indicated that RNFL thickness was positively correlated with peripapillary global VD(r=0.648,P<0.001),RNFL thickness was positively correlated with intrapapillary ring VD(r=0.427,P=0.015),and RNFL thickness was positively correlated with peripapillary VD(r=0.666,P<0.001).Conclusion:The results showed that the RNFL thickness around the optic disc was thinner in patients with unilateral RVO,especially in the inferior and temporal area,and the full area VD around the optic disc was decreased,especially in the internal ring,external ring and inferior area.In patients with unilateral RVO,peripapillary RNFL was positively correlated with peripapillary global,internal ring and external ring VD.
基金supported by the National Natural Science Foundation of China (32170367 and 32000146)the Fundamental Research Funds for the Central Universities, China (2021TS066 and GK202103063)the Excellent Graduate Training Program of Shaanxi Normal University, China (LHRCCX23181).
文摘Cotton is one of the most important economic crops in the world,and it is a major source of fiber in the textile industry.Strigolactones(SLs)are a class of carotenoid-derived plant hormones involved in many processes of plant growth and development,although the functions of SL in fiber development remain largely unknown.Here,we found that the endogenous SLs were significantly higher in fibers at 20 days post-anthesis(DPA).Exogenous SLs significantly increased fiber length and cell wall thickness.Furthermore,we cloned three key SL biosynthetic genes,namely GhD27,GhMAX3,and GhMAX4,which were highly expressed in fibers,and subcellular localization analyses revealed that GhD27,GhMAX3,and GhMAX4 were localized in the chloroplast.The exogenous expression of GhD27,GhMAX3,and GhMAX4 complemented the physiological phenotypes of d27,max3,and max4 mutations in Arabidopsis,respectively.Knockdown of GhD27,GhMAX3,and GhMAX4 in cotton resulted in increased numbers of axillary buds and leaves,reduced fiber length,and significantly reduced fiber thickness.These findings revealed that SLs participate in plant growth,fiber elongation,and secondary cell wall formation in cotton.These results provide new and effective genetic resources for improving cotton fiber yield and plant architecture.
文摘BACKGROUND Type 2 diabetes is a chronic,non-communicable disease with a substantial global impact,affecting a significant number of individuals.Its etiology is closely tied to imbalanced dietary practices and sedentary lifestyles.Conversely,increasing die-tary fiber(DF)intake has consistently demonstrated health benefits in numerous studies,including improvements in glycemic control and weight management.AIM To investigate the efficacy of DF interventions in the management of type 2 diabetes mellitus(T2DM).METHODS A systematic literature review was conducted to explore the association between DF intake and the management of T2DM.Following the inclusion and exclusion criteria,a total of 26 studies were included in this review.RESULTS The main strategies implied to increased DF intake were:High DF diet plus acarbose(2 studies);DF supplements(14 studies);and high DF diets(10 studies).Overall,most studies indicated that increased DF intake resulted in im-provements in glycemic control and weight management in T2DM patients.CONCLUSION DF represents a valuable strategy in the treatment of type 2 diabetes,improving health outcomes.DF intake offers the potential to improve quality of life and reduce complications and mortality associated with diabetes.Likewise,through supplements or enriched foods,DF contributes significantly to the control of several markers such as HbA1c,blood glucose,triglycerides,low-density lipoprotein,and body weight.
基金Fundamental Research Funds for the Central Universities of China(No.2232022D-10)Open Fund of State Key Laboratory of Biobased Fiber Manufacturing Technology,China(No.SKL202306)。
文摘Side-by-side bicomponent fibers have a spring-like three-dimensional spiral crimp structure and are widely used in elastic fabric.The difference in thermal shrinkage between different polymers can produce an unbalanced stress during the cooling process,and this unbalanced stress can be exploited to prepare naturally crimped fibers by spinning design.In this work,different types of polyamides(PAs)were selected for fabrication of the PA-based side-by-side bicomponent elastic fibers using melt spinning,and the structure development and performance of such bicomponent elastic fibers were studied.Meanwhile,thermoplastic PA elastomer(TPAE)with intrinsic elasticity was also used as one of the comparative materials.The block structure of the PA segment and the polyether segment in the TPAE molecule is the key to providing thermal shrinkage differences and forming a good interface structure.As a result,the crimp ratio of PA6/TPAE bicomponent elastic fiber is 7.23%,which is better than that of the currently commercialized T400 fiber(6.72%).The excellent crimp performance of PA6/TPAE bicomponent elastic fibers comes from the asymmetric distribution of the stress along the radial direction of the fibers during the cooling process,which is caused by the difference in thermal shrinkage between PA6 and TPAE.In addition,the crimp formability of the PA-based bicomponent elastic fibers could be improved by expanding the shrinkage stress through wet-heat treatment.The crimp ratio of PA6/TPAE bicomponent elastic fibers reaches the maximum(33.08%)after treatment at 100℃.At the same time,the fabric made of PA6/TPAE bicomponent elastic fibers has the excellent air and water vapor permeability,with an air permeability of 272.76 mm/s and a water vapor transmission rate of 406.71 g/(m^(2)·h).
