The dependence of Brillouin gain spectrum(BGS)characteristics,including the Brillouin frequency shift(BFS)and the BGS bandwidth,on germanium concentration in large-mode-area Ge-doped passive fibers is investigated the...The dependence of Brillouin gain spectrum(BGS)characteristics,including the Brillouin frequency shift(BFS)and the BGS bandwidth,on germanium concentration in large-mode-area Ge-doped passive fibers is investigated theoretically and experimentally.The simulation results show that the BFS is inversely proportional to GeO_(2)concentration,and the BGS bandwidth initially increases with the augment of GeO_(2)concentration,and then decreases.The BGSs of four fibers with core diameters of 10μm and 20μm for different GeO_(2)concentrations are compared experimentally.Experimental results demonstrate that with the same core diameter,the variations of BFS and BGS bandwidths with GeO_(2)concentration accord with the simulation results.Additionally,the BGS characteristics of three large-mode-area passive fibers with diameters of 10μm,25μm,and 30μm are measured,which confirm that the increasing of the fiber diameters will cause the BGS bandwidth to broaden.We believe that these results can provide valuable references for modulating the high-power narrowlinewidth fiber lasers and Brillouin fiber amplifiers.展开更多
Thermo-poro-mechanical responses along sliding zone/surface have been extensively studied.However,it has not been recognized that the potential contribution of other crucial engineering geological interfaces beyond th...Thermo-poro-mechanical responses along sliding zone/surface have been extensively studied.However,it has not been recognized that the potential contribution of other crucial engineering geological interfaces beyond the slip surface to progressive failure.Here,we aim to investigate the subsurface multiphysics of reservoir landslides under two extreme hydrologic conditions(i.e.wet and dry),particularly within sliding masses.Based on ultra-weak fiber Bragg grating(UWFBG)technology,we employ specialpurpose fiber optic sensing cables that can be implanted into boreholes as“nerves of the Earth”to collect data on soil temperature,water content,pore water pressure,and strain.The Xinpu landslide in the middle reach of the Three Gorges Reservoir Area in China was selected as a case study to establish a paradigm for in situ thermo-hydro-poro-mechanical monitoring.These UWFBG-based sensing cables were vertically buried in a 31 m-deep borehole at the foot of the landslide,with a resolution of 1 m except for the pressure sensor.We reported field measurements covering the period 2021 and 2022 and produced the spatiotemporal profiles throughout the borehole.Results show that wet years are more likely to motivate landslide motions than dry years.The annual thermally active layer of the landslide has a critical depth of roughly 9 m and might move downward in warmer years.The dynamic groundwater table is located at depths of 9e15 m,where the peaked strain undergoes a periodical response of leap and withdrawal to annual hydrometeorological cycles.These interface behaviors may support the interpretation of the contribution of reservoir regulation to slope stability,allowing us to correlate them to local damage events and potential global destabilization.This paper also offers a natural framework for interpreting thermo-hydro-poro-mechanical signatures from creeping reservoir bank slopes,which may form the basis for a landslide monitoring and early warning system.展开更多
A wavelength-interval switchable Brillouin–Raman random fiber laser(BRRFL) based on Brillouin pump(BP) manipulation is proposed in this paper. The proposed wavelength-interval switchable BRRFL has a full-open cavity ...A wavelength-interval switchable Brillouin–Raman random fiber laser(BRRFL) based on Brillouin pump(BP) manipulation is proposed in this paper. The proposed wavelength-interval switchable BRRFL has a full-open cavity configuration, featuring multiwavelength output with wavelength interval of double Brillouin frequency shifts. Through simultaneously injecting the BP light and its first-order stimulated Brillouin-scattered light into the cavity, the laser output exhibits a wavelength interval of single Brillouin frequency shift. The wavelength-interval switching effect can be manipulated by controlling the power of the first-order stimulated Brillouin scattering light. The experimental results show the multiwavelength output can be switched between double Brillouin frequency shift multiwavelength emission with a broad bandwidth of approximately 60 nm and single Brillouin frequency shift multiwavelength emission of 44 nm. The flexible optically controlled random fiber laser with switchable wavelength interval makes it useful for a wide range of applications and holds significant potential in the field of wavelength-division multiplexing optical communication.展开更多
Temperature regulating fibers(TRF_(s)) with high enthalpy and high form stability are the key factors for thermal management. However, the enthalpies of most TRFsare not high, and the preparation methods are still at ...Temperature regulating fibers(TRF_(s)) with high enthalpy and high form stability are the key factors for thermal management. However, the enthalpies of most TRFsare not high, and the preparation methods are still at the laboratory scale. It remains a great challenge to use industrial spinning equipment to achieve continuous processing of TRF_(s) with excellent thermal and mechanical properties. Here, polyamide 6(PA6) based TRF_(s) with a sheath-core structure were prepared by bicomponent melt-spinning. The sheath-core TRF(TRF_(sc)) are composed of PA6 as sheath and functional PA6 as core, which are filled with the shape stable phase change materials(ssPCM),dendritic silica@polyethylene glycol(SiO_(2)@PEG). With the aid of the sheath structure, the filling content of SiO_(2)@PEG can reach 30 %, so that the enthalpy of the TRF_(s) can be as high as 21.3 J/g. The ultra-high enthalpy guarantees the temperature regulation ability during the alternating process of cooling and heating. In hot environment, the temperature regulation time is 6.59 min, and the temperature difference is 12.93℃. In addition, the mechanical strength of the prepared TRF_(sc) reaches 2.26 cN/dtex, which can fully meet its application in the field of thermal management textiles and devices to manage the temperature regulation of the human body or precision equipment, etc.展开更多
Weakly-coupled mode division multiplexing(MDM)technique is considered a promising candidate to enhance the capacity of an optical transmission system,in which mode multiplexers/demultiplexers(MMUX/MDEMUX)with low inse...Weakly-coupled mode division multiplexing(MDM)technique is considered a promising candidate to enhance the capacity of an optical transmission system,in which mode multiplexers/demultiplexers(MMUX/MDEMUX)with low insertion loss and modal crosstalk are the key components.In this paper,a low-modal-crosstalk 4-mode MMUX/MDEMUX for the weakly-coupled triple-ring-core few-mode fiber(TRC-FMF)is designed and fabricated with side-polishing processing.The measurement results show that a pair of MMUX/MDEMUX and 25 km weakly-coupled TRC-FMF MDM link achieve low modal crosstalk of lower than−17.5 dB and insertion loss of lower than 11.56 dB for all the four modes.Based on the TRC-FMF and all-fiber MMUX/MDEMUX,an experiment for 25 km real-time 4-mode 3-λwavelength division multiplexing(WDM)-MDM transmission is conducted using commercial 400G optical transport network(OTN)transceivers.The experimental results prove weakly-coupled MDM techniques facilitate a smooth upgrade of the optical transmission system.展开更多
Our primary objective is to mitigate the adverse effects of temperature fluctuations on the optical frequency transmission system by reducing the length of the interferometer.Following optimization,the phase-temperatu...Our primary objective is to mitigate the adverse effects of temperature fluctuations on the optical frequency transmission system by reducing the length of the interferometer.Following optimization,the phase-temperature coefficient of the optical system is reduced to approximately 1.35 fs/K.By applying a sophisticated temperature control to the remained“out-of-loop”optics fiber,the noise floor of the system has been effectively lowered to 10−21 level.Based on this performance-enhanced transfer system,we demonstrate coherent transmission of optical frequency through 500-km spooled fiber link.After being actively compensated,the transfer instability of 4.5×10^(−16) at the averaging time of 1 s and 5.6×10^(−21) at 10000 s is demonstrated.The frequency uncertainty of received light at remote site relative to that of the origin light at local site is achieved to be 1.15×10^(−19).This enhanced system configuration is particularly well suited for future long-distance frequency transmission and comparison of the most advanced optical clock signals.展开更多
Images and videos provide a wealth of information for people in production and life.Although most digital information is transmitted via optical fiber,the image acquisition and transmission processes still rely heavil...Images and videos provide a wealth of information for people in production and life.Although most digital information is transmitted via optical fiber,the image acquisition and transmission processes still rely heavily on electronic circuits.The development of all-optical transmission networks and optical computing frameworks has pointed to the direction for the next generation of data transmission and information processing.Here,we propose a high-speed,low-cost,multiplexed parallel and one-piece all-fiber architecture for image acquisition,encoding,and transmission,called the Multicore Fiber Acquisition and Transmission Image System(MFAT).Based on different spatial and modal channels of the multicore fiber,fiber-coupled self-encoding,and digital aperture decoding technology,scenes can be observed directly from up to 1 km away.The expansion of capacity provides the possibility of parallel coded transmission of multimodal high-quality data.MFAT requires no additional signal transmitting and receiving equipment.The all-fiber processing saves the time traditionally spent on signal conversion and image pre-processing(compression,encoding,and modulation).Additionally,it provides an effective solution for 2D information acquisition and transmission tasks in extreme environments such as high temperatures and electromagnetic interference.展开更多
An all-fiber polarization maintaining high-power laser system operating at 1.7 μm based on the Ramaninduced soliton self-frequency shifting effect is demonstrated. The entirely fiberized system is built by erbiumdope...An all-fiber polarization maintaining high-power laser system operating at 1.7 μm based on the Ramaninduced soliton self-frequency shifting effect is demonstrated. The entirely fiberized system is built by erbiumdoped oscillator and two-stage amplifiers with polarization maintaining commercial silica fibers and devices, which can provide robust and stable soliton generation. High-power soliton laser with the average power of 0.28 W,the repetition rate of 42.7 MHz, and pulse duration of 515 fs is generated directly from the main amplifier.Our experiment provides a feasible method for high-power all-fiber polarization maintaining femtosecond laser generation working at 1.7 μm.展开更多
A D-shaped fiber is coated with a new two-dimensional nanomaterial,violet phosphorus(VP),to create a saturable absorber(SA)with a modulation depth of 3.68%.Subsequently,the SA is inserted into a fiber laser,enabling s...A D-shaped fiber is coated with a new two-dimensional nanomaterial,violet phosphorus(VP),to create a saturable absorber(SA)with a modulation depth of 3.68%.Subsequently,the SA is inserted into a fiber laser,enabling successful generation of dark solitons and bright–dark soliton pairs through adjustment of the polarization state within the cavity.Through further study,mode-locked pulses are achieved,proving the existence of polarization-locked vector solitons.The results indicate that VP can be used as a polarization-independent SA.展开更多
An implementation of high-precision time transfer over a 1839-km field fiber loop back link between two provincial capitals of China,Xi’an and Taiyuan,is reported.Time transfer stabilities of 6.5 ps at averaging time...An implementation of high-precision time transfer over a 1839-km field fiber loop back link between two provincial capitals of China,Xi’an and Taiyuan,is reported.Time transfer stabilities of 6.5 ps at averaging time of 1 s and 4.6 ps at 40000 s were achieved.The uncertainty for the time transfer system was evaluated,showing a budget of 56.2 ps.These results stand for a significant milestone in achieving high-precision time transfer over a field fiber link spanning thousands of kilometers,signifying a record-breaking achievement for the real-field time transfer in both stability and distance,which paves the way for constructing the nationwide high-precision time service via fiber network.展开更多
The carbon black(CB)is introduced to manufacture CB/graphene oxide(GO)composite material to mitigate limitations of GO as a saturable absorber with the excellent performance in ultrafast fiber lasers.At a central wave...The carbon black(CB)is introduced to manufacture CB/graphene oxide(GO)composite material to mitigate limitations of GO as a saturable absorber with the excellent performance in ultrafast fiber lasers.At a central wavelength of 1555.5 nm,the stable mode-locked pulse with width of 656 fs,repetition rate of 20.16 MHz,and high signal-to-noise ratio of 82.07 dB is experimentally obtained.Additionally,experimental observations for pulsation phenomena of vector biperiodic solitons combining period-1 and period-17,period-2 and period-32,period-3 and period-36 are verified via simulations.展开更多
Nyquist pulses have wide applications in many areas,from electronics to optics.Mode-locked lasers are ideal platforms to generate such pulses.However,how to generate high-quality Nyquist pulses in mode-locked lasers r...Nyquist pulses have wide applications in many areas,from electronics to optics.Mode-locked lasers are ideal platforms to generate such pulses.However,how to generate high-quality Nyquist pulses in mode-locked lasers remains elusive.We address this problem by managing different physical effects in mode-locked fiber lasers through extensive numerical simulations.We find that net dispersion,linear loss,gain and filter shaping can affect the quality of Nyquist pulses significantly.We also demonstrate that Nyquist pulses experience similariton shaping due to the nonlinear attractor effect in the gain medium.Our work may contribute to the design of Nyquist pulse sources and enrich the understanding of pulse shaping dynamics in mode-locked lasers.展开更多
Lack of dietary fiber contributes to many health issues, particularly chronic vascular diseases. Mixed linkage β-1.3 - 1.4 beta-glucan (beta-glucan, in this paper) is a confirmed beneficial ingredient for the human d...Lack of dietary fiber contributes to many health issues, particularly chronic vascular diseases. Mixed linkage β-1.3 - 1.4 beta-glucan (beta-glucan, in this paper) is a confirmed beneficial ingredient for the human diet through reduction of cholesterol and the glycemic index. Barley contains the highest beta-glucan content of all the grains, and in this study, a percentage of flour from two high beta glucan lines was, each, added to an array of wheat-based food products to measure how it impacted total dietary fiber. Results showed that beta-glucan content was higher in all the products containing the added high beta-glucan flour, along with increased total dietary fiber content. Protein content in the food products is also increased with the higher protein in the barley flours added. Beta-glucan content in the barley-added products increased to 1.2% - 4.0% versus 0.2% - 0.5% in the pure wheat products, while the dietary fibers increased to 3.5% - 24.4% versus 2.1% - 9.1% in pure wheat product controls. This research provided experimental evidence that using a high beta-glucan barley ingredient in food can increase dietary fiber to benefit health.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
Increasing data indicate that cancer cell migration is regulated by extracellular matrixes and their surrounding biochemical microenvironment,playing a crucial role in pathological processes such as tumor invasion and...Increasing data indicate that cancer cell migration is regulated by extracellular matrixes and their surrounding biochemical microenvironment,playing a crucial role in pathological processes such as tumor invasion and metastasis.However,conventional two-dimensional cell culture and animal models have limitations in studying the influence of tumor microenvironment on cancer cell migration.Fortunately,the further development of microfluidic technology has provided solutions for the study of such questions.We utilize microfluidic chip to build a random collagen fiber microenvironment(RFM)model and an oriented collagen fiber microenvironment(OFM)model that resemble early stage and late stage breast cancer microenvironments,respectively.By combining cell culture,biochemical concentration gradient construction,and microscopic imaging techniques,we investigate the impact of different collagen fiber biochemical microenvironments on the migration of breast cancer MDA-MB-231-RFP cells.The results show that MDA-MB-231-RFP cells migrate further in the OFM model compared to the RFM model,with significant differences observed.Furthermore,we establish concentration gradients of the anticancer drug paclitaxel in both the RFM and OFM models and find that paclitaxel significantly inhibits the migration of MDA-MB-231-RFP cells in the RFM model,with stronger inhibition on the high concentration side compared to the low concentration side.However,the inhibitory effect of paclitaxel on the migration of MDA-MB-231-RFP cells in the OFM model is weak.These findings suggest that the oriented collagen fiber microenvironment resembling the late-stage tumor microenvironment is more favorable for cancer cell migration and that the effectiveness of anticancer drugs is diminished.The RFM and OFM models constructed in this study not only provide a platform for studying the mechanism of cancer development,but also serve as a tool for the initial measurement of drug screening.展开更多
In this work,we theoretically unlock the potential of Ho^(3+)-doped InF3 fiber for efficient~3.2μm laser generation(from the 5F4,5S2→5F5 transition),by employing a novel dual-wavelength pumping scheme at 1150 nm and...In this work,we theoretically unlock the potential of Ho^(3+)-doped InF3 fiber for efficient~3.2μm laser generation(from the 5F4,5S2→5F5 transition),by employing a novel dual-wavelength pumping scheme at 1150 nm and 980 nm,for the first time.Under clad-coupled 1150 nm pumping of 5 W,~3.2μm power of 3.6 W has been predicted with the optical-to-optical efficiency of 14.4%.Further efficient power scaling,however,is blocked by the output saturation with 980 nm pumping.To alleviate this behavior,the cascaded 5I5→5I6 transition,targeting~3.9μm,has been activated simultaneously,therefore accelerating the population circulation between the laser upper level 5F4,5S2 and long-lived 5I6 level under 980 nm pumping.As a result,enhanced~3.2μm power of 4.68 W has been obtained with optical-to-optical efficiency of 15.6%.Meanwhile the~3.9μm laser,yielding power of 2.76 W with optical-to-optical efficiency of 9.2%,is theoretically achievable as well with a moderate heat load,of which the performance is even better than the prior experimentally and theoretically reported Ho^(3+)-doped InF3 fiber lasers emitting at~3.9μm alone.This work demonstrates a versatile platform for laser generation at~3.2μm and~3.9μm,thus providing the new opportunities for many potential applications,e.g.,polymer processing,infrared countermeasures,and free-space communications.展开更多
Because inferior mechanical strength of granite polymer composite(GPC)has become the main drawback limiting its application and popularization,Mo fibers were added into(GPC)to improve its mechanical strength.Mechanica...Because inferior mechanical strength of granite polymer composite(GPC)has become the main drawback limiting its application and popularization,Mo fibers were added into(GPC)to improve its mechanical strength.Mechanical properties of matrix materials with different mass ratio of resin and stabilizer(MRRS)were investigated systematically.The influences of MRRS on interface bonding strength of Mo fiber-matrix,wettability and mechanical strength of GPC were discussed,respectively,and the theoretical calculation result of MRRS k was obtained,with the optimal value of k=4.When k=4,tensile strength,tensile strain and fracture stress of the cured resin achieve the maximum values.But for k=7,the corresponding values reach the minimum.With the increase of MRRS k,surface free energy of the cured resin first increases and then decreases,while contact angles between Mo sample and matrix have displayed the opposite trend.Wettability of resin to Mo fiber is the best at k=4.Pulling load of Mo fiber and interface bonding strength appear the maximum at k=4,followed by k=5,k=3 the third,and k=7 the minimum.When k=4,mechanical properties of Mo fiber-reinforced GPC are optimal,which is consistent with the result of theoretical calculation.This study is of great significance to get better component formulas of Mo fiber reinforced GPC and to improve its application in machine tools.展开更多
Bi-activated photonic materials are promising for various applications in high-capacity telecommunication,tunable laser,and advanced bioimaging and sensing.Although various Bi-doped material candidates have been explo...Bi-activated photonic materials are promising for various applications in high-capacity telecommunication,tunable laser,and advanced bioimaging and sensing.Although various Bi-doped material candidates have been explored,manufacturing of Bi heavily doped fiber with excellent optical activity remains a long-standing challenge.Herein,a novel viscosity evolutional behavior mediated strategy for manufacturing of Bi-doped active fiber with high dopant solubility is proposed.The intrinsic relation among the evolution of Bi,reaction temperature and viscosity of the glass system is established.Importantly,the effective avenue to prevent the undesired deactivation of Bi during fiber drawing by tuning the temperature dependent viscosity evolution is built.By applying the strategy,for the first time we demonstrate the success in fabrication of heavily doped Bi active fiber.Furthermore,the principal fiber amplifier device is constructed and broadband optical signal amplification is realized.Our findings indicate the effectiveness of the proposed temperature dependent viscosity mediated strategy for developing novel photonic active fiber,and they also demonstrate the great potential for application in the next-generation high-capacity telecommunication system.展开更多
The self-powered tissue engineering scaffold with good biocompatibility is of great significance for stimulating nerve cell growth.In this study,silk fibroin(SF)-based fibers with regulatable structure and piezoelectr...The self-powered tissue engineering scaffold with good biocompatibility is of great significance for stimulating nerve cell growth.In this study,silk fibroin(SF)-based fibers with regulatable structure and piezoelectric performance are fabricated by dry-spinning and post-treatment.The concentration of SF and calcium ion in spinning dope and the post-treatment affect the conformation transition and crystallinity of SF.As a result,the SF fibers exhibit high piezoelectric coefficient d_(33)(3.24 pm/V)and output voltage(~27 V).Furthermore,these piezoelectric fibers promote the growth of PC-12 cells,demonstrating the promising potential for nerve repair and other energy harvester.展开更多
A method for in-situ stress measurement via fiber optics was proposed. The method utilizes the relationship between rock mass elastic parameters and in-situ stress. The approach offers the advantage of long-term stres...A method for in-situ stress measurement via fiber optics was proposed. The method utilizes the relationship between rock mass elastic parameters and in-situ stress. The approach offers the advantage of long-term stress measurements with high spatial resolution and frequency, significantly enhancing the ability to measure in-situ stress. The sensing casing, spirally wrapped with fiber optic, is cemented into the formation to establish a formation sensing nerve. Injecting fluid into the casing generates strain disturbance, establishing the relationship between rock mass properties and treatment pressure.Moreover, an optimization algorithm is established to invert the elastic parameters of formation via fiber optic strains. In the first part of this paper series, we established the theoretical basis for the inverse differential strain analysis method for in-situ stress measurement, which was subsequently verified using an analytical model. This paper is the fundamental basis for the inverse differential strain analysis method.展开更多
基金Project supported by the Key-Area Research and Development Program of Guangdong Province,China(Grant No.2018B090904001)the National Natural Science Foundation of China(Grant Nos.61805261,61405202,and 61705243)the Youth Innovation Promotion Association,Chinese Academy of Sciences(Grant No.2020252)。
文摘The dependence of Brillouin gain spectrum(BGS)characteristics,including the Brillouin frequency shift(BFS)and the BGS bandwidth,on germanium concentration in large-mode-area Ge-doped passive fibers is investigated theoretically and experimentally.The simulation results show that the BFS is inversely proportional to GeO_(2)concentration,and the BGS bandwidth initially increases with the augment of GeO_(2)concentration,and then decreases.The BGSs of four fibers with core diameters of 10μm and 20μm for different GeO_(2)concentrations are compared experimentally.Experimental results demonstrate that with the same core diameter,the variations of BFS and BGS bandwidths with GeO_(2)concentration accord with the simulation results.Additionally,the BGS characteristics of three large-mode-area passive fibers with diameters of 10μm,25μm,and 30μm are measured,which confirm that the increasing of the fiber diameters will cause the BGS bandwidth to broaden.We believe that these results can provide valuable references for modulating the high-power narrowlinewidth fiber lasers and Brillouin fiber amplifiers.
基金We acknowledge the funding support from the National Science Fund for Distinguished Young Scholars of National Natural Science Foundation of China(Grant No.42225702)the National Natural Science Foundation of China(Grant No.42077235).
文摘Thermo-poro-mechanical responses along sliding zone/surface have been extensively studied.However,it has not been recognized that the potential contribution of other crucial engineering geological interfaces beyond the slip surface to progressive failure.Here,we aim to investigate the subsurface multiphysics of reservoir landslides under two extreme hydrologic conditions(i.e.wet and dry),particularly within sliding masses.Based on ultra-weak fiber Bragg grating(UWFBG)technology,we employ specialpurpose fiber optic sensing cables that can be implanted into boreholes as“nerves of the Earth”to collect data on soil temperature,water content,pore water pressure,and strain.The Xinpu landslide in the middle reach of the Three Gorges Reservoir Area in China was selected as a case study to establish a paradigm for in situ thermo-hydro-poro-mechanical monitoring.These UWFBG-based sensing cables were vertically buried in a 31 m-deep borehole at the foot of the landslide,with a resolution of 1 m except for the pressure sensor.We reported field measurements covering the period 2021 and 2022 and produced the spatiotemporal profiles throughout the borehole.Results show that wet years are more likely to motivate landslide motions than dry years.The annual thermally active layer of the landslide has a critical depth of roughly 9 m and might move downward in warmer years.The dynamic groundwater table is located at depths of 9e15 m,where the peaked strain undergoes a periodical response of leap and withdrawal to annual hydrometeorological cycles.These interface behaviors may support the interpretation of the contribution of reservoir regulation to slope stability,allowing us to correlate them to local damage events and potential global destabilization.This paper also offers a natural framework for interpreting thermo-hydro-poro-mechanical signatures from creeping reservoir bank slopes,which may form the basis for a landslide monitoring and early warning system.
基金Poject supported by the National Natural Science Foundation of China(Grant Nos.62175116 and 62311530343)the Postgraduate Research Innovation Program of Jiangsu Province,China(Grant No.KYCX22_0913)。
文摘A wavelength-interval switchable Brillouin–Raman random fiber laser(BRRFL) based on Brillouin pump(BP) manipulation is proposed in this paper. The proposed wavelength-interval switchable BRRFL has a full-open cavity configuration, featuring multiwavelength output with wavelength interval of double Brillouin frequency shifts. Through simultaneously injecting the BP light and its first-order stimulated Brillouin-scattered light into the cavity, the laser output exhibits a wavelength interval of single Brillouin frequency shift. The wavelength-interval switching effect can be manipulated by controlling the power of the first-order stimulated Brillouin scattering light. The experimental results show the multiwavelength output can be switched between double Brillouin frequency shift multiwavelength emission with a broad bandwidth of approximately 60 nm and single Brillouin frequency shift multiwavelength emission of 44 nm. The flexible optically controlled random fiber laser with switchable wavelength interval makes it useful for a wide range of applications and holds significant potential in the field of wavelength-division multiplexing optical communication.
基金financially supported by the National Natural Science Foundation of China (52073047)the Science and Technology Commission of Shanghai Municipality (20JC1414900)+1 种基金the Program of Shanghai Technology Research Leader (20XD1433700)the INTERNATIONAL COOPERATION Fund of the Science and Technology Commission of Shanghai Municipality (20520740800)。
文摘Temperature regulating fibers(TRF_(s)) with high enthalpy and high form stability are the key factors for thermal management. However, the enthalpies of most TRFsare not high, and the preparation methods are still at the laboratory scale. It remains a great challenge to use industrial spinning equipment to achieve continuous processing of TRF_(s) with excellent thermal and mechanical properties. Here, polyamide 6(PA6) based TRF_(s) with a sheath-core structure were prepared by bicomponent melt-spinning. The sheath-core TRF(TRF_(sc)) are composed of PA6 as sheath and functional PA6 as core, which are filled with the shape stable phase change materials(ssPCM),dendritic silica@polyethylene glycol(SiO_(2)@PEG). With the aid of the sheath structure, the filling content of SiO_(2)@PEG can reach 30 %, so that the enthalpy of the TRF_(s) can be as high as 21.3 J/g. The ultra-high enthalpy guarantees the temperature regulation ability during the alternating process of cooling and heating. In hot environment, the temperature regulation time is 6.59 min, and the temperature difference is 12.93℃. In addition, the mechanical strength of the prepared TRF_(sc) reaches 2.26 cN/dtex, which can fully meet its application in the field of thermal management textiles and devices to manage the temperature regulation of the human body or precision equipment, etc.
基金supported in part by the ZTE Industry-University-Institute Cooperation Funds.
文摘Weakly-coupled mode division multiplexing(MDM)technique is considered a promising candidate to enhance the capacity of an optical transmission system,in which mode multiplexers/demultiplexers(MMUX/MDEMUX)with low insertion loss and modal crosstalk are the key components.In this paper,a low-modal-crosstalk 4-mode MMUX/MDEMUX for the weakly-coupled triple-ring-core few-mode fiber(TRC-FMF)is designed and fabricated with side-polishing processing.The measurement results show that a pair of MMUX/MDEMUX and 25 km weakly-coupled TRC-FMF MDM link achieve low modal crosstalk of lower than−17.5 dB and insertion loss of lower than 11.56 dB for all the four modes.Based on the TRC-FMF and all-fiber MMUX/MDEMUX,an experiment for 25 km real-time 4-mode 3-λwavelength division multiplexing(WDM)-MDM transmission is conducted using commercial 400G optical transport network(OTN)transceivers.The experimental results prove weakly-coupled MDM techniques facilitate a smooth upgrade of the optical transmission system.
基金supported by the National Natural Science Foundation of China(Grant Nos.12303076 and 12303077).
文摘Our primary objective is to mitigate the adverse effects of temperature fluctuations on the optical frequency transmission system by reducing the length of the interferometer.Following optimization,the phase-temperature coefficient of the optical system is reduced to approximately 1.35 fs/K.By applying a sophisticated temperature control to the remained“out-of-loop”optics fiber,the noise floor of the system has been effectively lowered to 10−21 level.Based on this performance-enhanced transfer system,we demonstrate coherent transmission of optical frequency through 500-km spooled fiber link.After being actively compensated,the transfer instability of 4.5×10^(−16) at the averaging time of 1 s and 5.6×10^(−21) at 10000 s is demonstrated.The frequency uncertainty of received light at remote site relative to that of the origin light at local site is achieved to be 1.15×10^(−19).This enhanced system configuration is particularly well suited for future long-distance frequency transmission and comparison of the most advanced optical clock signals.
基金financial supports from the National Key R&D Program of China (2021YFA1401103)the National Natural Science Foundation of China (61925502 and 51772145)
文摘Images and videos provide a wealth of information for people in production and life.Although most digital information is transmitted via optical fiber,the image acquisition and transmission processes still rely heavily on electronic circuits.The development of all-optical transmission networks and optical computing frameworks has pointed to the direction for the next generation of data transmission and information processing.Here,we propose a high-speed,low-cost,multiplexed parallel and one-piece all-fiber architecture for image acquisition,encoding,and transmission,called the Multicore Fiber Acquisition and Transmission Image System(MFAT).Based on different spatial and modal channels of the multicore fiber,fiber-coupled self-encoding,and digital aperture decoding technology,scenes can be observed directly from up to 1 km away.The expansion of capacity provides the possibility of parallel coded transmission of multimodal high-quality data.MFAT requires no additional signal transmitting and receiving equipment.The all-fiber processing saves the time traditionally spent on signal conversion and image pre-processing(compression,encoding,and modulation).Additionally,it provides an effective solution for 2D information acquisition and transmission tasks in extreme environments such as high temperatures and electromagnetic interference.
基金Supported by the National Natural Science Foundation of China (Grant Nos. 10225417 and 61675009)the Natural Science Foundation of Beijing Municipality (Grant Nos. 4204091 and KZ201910005006)the China Postdoctoral Science Foundation (Grant No. 212423)。
文摘An all-fiber polarization maintaining high-power laser system operating at 1.7 μm based on the Ramaninduced soliton self-frequency shifting effect is demonstrated. The entirely fiberized system is built by erbiumdoped oscillator and two-stage amplifiers with polarization maintaining commercial silica fibers and devices, which can provide robust and stable soliton generation. High-power soliton laser with the average power of 0.28 W,the repetition rate of 42.7 MHz, and pulse duration of 515 fs is generated directly from the main amplifier.Our experiment provides a feasible method for high-power all-fiber polarization maintaining femtosecond laser generation working at 1.7 μm.
基金supported by the National Natural Science Foundation of China(Grant Nos.62005212 and 12075190)the Young Talent Fund of University Association for Science and Technology in Shaanxi,China(Grant No.20210112)+2 种基金the New Star Project of Science and Technology of Shaanxi Province(Grant No.2022KJXX-69),the Fund for Outstanding Young Talents of China Academy of Space Technology(Xi’an)(Grant No.Y21-RCFYJQ1-03)the Young Elite Scientists Sponsorship Program by CAST(Grant No.2022QNRC001)the Open Foundation of State Key Laboratory of Transient Optics and Photonics(Grant No.SKLST202207).
文摘A D-shaped fiber is coated with a new two-dimensional nanomaterial,violet phosphorus(VP),to create a saturable absorber(SA)with a modulation depth of 3.68%.Subsequently,the SA is inserted into a fiber laser,enabling successful generation of dark solitons and bright–dark soliton pairs through adjustment of the polarization state within the cavity.Through further study,mode-locked pulses are achieved,proving the existence of polarization-locked vector solitons.The results indicate that VP can be used as a polarization-independent SA.
基金supported by the National Major Science and Technology Infrastructure Project of China,for“High Precision Ground-based Time Service System”(Grant No.2017-000052-73-01-002401)the National Natural Science Foundation of China(Grant No.12033007)。
文摘An implementation of high-precision time transfer over a 1839-km field fiber loop back link between two provincial capitals of China,Xi’an and Taiyuan,is reported.Time transfer stabilities of 6.5 ps at averaging time of 1 s and 4.6 ps at 40000 s were achieved.The uncertainty for the time transfer system was evaluated,showing a budget of 56.2 ps.These results stand for a significant milestone in achieving high-precision time transfer over a field fiber link spanning thousands of kilometers,signifying a record-breaking achievement for the real-field time transfer in both stability and distance,which paves the way for constructing the nationwide high-precision time service via fiber network.
基金supported by the National Natural Science Foundation of China(Grant Nos.12261131495 and 12475008)the Scientific Research and Developed Fund of Zhejiang A&F University(Grant No.2021FR0009).
文摘The carbon black(CB)is introduced to manufacture CB/graphene oxide(GO)composite material to mitigate limitations of GO as a saturable absorber with the excellent performance in ultrafast fiber lasers.At a central wavelength of 1555.5 nm,the stable mode-locked pulse with width of 656 fs,repetition rate of 20.16 MHz,and high signal-to-noise ratio of 82.07 dB is experimentally obtained.Additionally,experimental observations for pulsation phenomena of vector biperiodic solitons combining period-1 and period-17,period-2 and period-32,period-3 and period-36 are verified via simulations.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11621404,11561121003,11727812,61775059,12074122,62022033,and 11704123)Shanghai Rising-Star Program,the Sustainedly Supported Foundation by the National Key Laboratory of Science and Technology on Space Microwave(Grant No.HTKT2022KL504008)+1 种基金Shanghai Natural Science Foundation(Grant No.23ZR1419000)the National Key Laboratory Foundation of China(Grant No.6142411196307).
文摘Nyquist pulses have wide applications in many areas,from electronics to optics.Mode-locked lasers are ideal platforms to generate such pulses.However,how to generate high-quality Nyquist pulses in mode-locked lasers remains elusive.We address this problem by managing different physical effects in mode-locked fiber lasers through extensive numerical simulations.We find that net dispersion,linear loss,gain and filter shaping can affect the quality of Nyquist pulses significantly.We also demonstrate that Nyquist pulses experience similariton shaping due to the nonlinear attractor effect in the gain medium.Our work may contribute to the design of Nyquist pulse sources and enrich the understanding of pulse shaping dynamics in mode-locked lasers.
文摘Lack of dietary fiber contributes to many health issues, particularly chronic vascular diseases. Mixed linkage β-1.3 - 1.4 beta-glucan (beta-glucan, in this paper) is a confirmed beneficial ingredient for the human diet through reduction of cholesterol and the glycemic index. Barley contains the highest beta-glucan content of all the grains, and in this study, a percentage of flour from two high beta glucan lines was, each, added to an array of wheat-based food products to measure how it impacted total dietary fiber. Results showed that beta-glucan content was higher in all the products containing the added high beta-glucan flour, along with increased total dietary fiber content. Protein content in the food products is also increased with the higher protein in the barley flours added. Beta-glucan content in the barley-added products increased to 1.2% - 4.0% versus 0.2% - 0.5% in the pure wheat products, while the dietary fibers increased to 3.5% - 24.4% versus 2.1% - 9.1% in pure wheat product controls. This research provided experimental evidence that using a high beta-glucan barley ingredient in food can increase dietary fiber to benefit health.
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support from the National Natural Science Foundation of China(Grant Nos.11974066,12174041,12104134,T2350007,and 12347178)the Fundamental and Advanced Research Program of Chongqing(Grant No.cstc2019jcyj-msxm X0477)+3 种基金the Natural Science Foundation of Chongqing(Grant No.CSTB2022NSCQMSX1260)the Science and Technology Research Program of Chongqing Municipal Education Commission(Grant No.KJQN202301333)the Scientific Research Fund of Chongqing University of Arts and Sciences(Grant Nos.R2023HH03 and P2022HH05)College Students’Innovation and Entrepreneurship Training Program of Chongqing Municipal(Grant No.S202310642002)。
文摘Increasing data indicate that cancer cell migration is regulated by extracellular matrixes and their surrounding biochemical microenvironment,playing a crucial role in pathological processes such as tumor invasion and metastasis.However,conventional two-dimensional cell culture and animal models have limitations in studying the influence of tumor microenvironment on cancer cell migration.Fortunately,the further development of microfluidic technology has provided solutions for the study of such questions.We utilize microfluidic chip to build a random collagen fiber microenvironment(RFM)model and an oriented collagen fiber microenvironment(OFM)model that resemble early stage and late stage breast cancer microenvironments,respectively.By combining cell culture,biochemical concentration gradient construction,and microscopic imaging techniques,we investigate the impact of different collagen fiber biochemical microenvironments on the migration of breast cancer MDA-MB-231-RFP cells.The results show that MDA-MB-231-RFP cells migrate further in the OFM model compared to the RFM model,with significant differences observed.Furthermore,we establish concentration gradients of the anticancer drug paclitaxel in both the RFM and OFM models and find that paclitaxel significantly inhibits the migration of MDA-MB-231-RFP cells in the RFM model,with stronger inhibition on the high concentration side compared to the low concentration side.However,the inhibitory effect of paclitaxel on the migration of MDA-MB-231-RFP cells in the OFM model is weak.These findings suggest that the oriented collagen fiber microenvironment resembling the late-stage tumor microenvironment is more favorable for cancer cell migration and that the effectiveness of anticancer drugs is diminished.The RFM and OFM models constructed in this study not only provide a platform for studying the mechanism of cancer development,but also serve as a tool for the initial measurement of drug screening.
基金supported in parts by the National Natural Science Foundation of China under Grants No.62005040 and No.U20A20210.
文摘In this work,we theoretically unlock the potential of Ho^(3+)-doped InF3 fiber for efficient~3.2μm laser generation(from the 5F4,5S2→5F5 transition),by employing a novel dual-wavelength pumping scheme at 1150 nm and 980 nm,for the first time.Under clad-coupled 1150 nm pumping of 5 W,~3.2μm power of 3.6 W has been predicted with the optical-to-optical efficiency of 14.4%.Further efficient power scaling,however,is blocked by the output saturation with 980 nm pumping.To alleviate this behavior,the cascaded 5I5→5I6 transition,targeting~3.9μm,has been activated simultaneously,therefore accelerating the population circulation between the laser upper level 5F4,5S2 and long-lived 5I6 level under 980 nm pumping.As a result,enhanced~3.2μm power of 4.68 W has been obtained with optical-to-optical efficiency of 15.6%.Meanwhile the~3.9μm laser,yielding power of 2.76 W with optical-to-optical efficiency of 9.2%,is theoretically achievable as well with a moderate heat load,of which the performance is even better than the prior experimentally and theoretically reported Ho^(3+)-doped InF3 fiber lasers emitting at~3.9μm alone.This work demonstrates a versatile platform for laser generation at~3.2μm and~3.9μm,thus providing the new opportunities for many potential applications,e.g.,polymer processing,infrared countermeasures,and free-space communications.
基金Fouded by the National Natural Science Foundation of China(No.51175308)the National Science and Technology Major Project of China(No.2012ZX04010032)。
文摘Because inferior mechanical strength of granite polymer composite(GPC)has become the main drawback limiting its application and popularization,Mo fibers were added into(GPC)to improve its mechanical strength.Mechanical properties of matrix materials with different mass ratio of resin and stabilizer(MRRS)were investigated systematically.The influences of MRRS on interface bonding strength of Mo fiber-matrix,wettability and mechanical strength of GPC were discussed,respectively,and the theoretical calculation result of MRRS k was obtained,with the optimal value of k=4.When k=4,tensile strength,tensile strain and fracture stress of the cured resin achieve the maximum values.But for k=7,the corresponding values reach the minimum.With the increase of MRRS k,surface free energy of the cured resin first increases and then decreases,while contact angles between Mo sample and matrix have displayed the opposite trend.Wettability of resin to Mo fiber is the best at k=4.Pulling load of Mo fiber and interface bonding strength appear the maximum at k=4,followed by k=5,k=3 the third,and k=7 the minimum.When k=4,mechanical properties of Mo fiber-reinforced GPC are optimal,which is consistent with the result of theoretical calculation.This study is of great significance to get better component formulas of Mo fiber reinforced GPC and to improve its application in machine tools.
基金support from the National Key R&D Program of China(2020YFB1805901)the National Science Fund for Distinguished Young Scholars(62125502)+7 种基金the National Natural Science Foundation of China(51972113,52302002 and 62305115)the Local Innovative and Research Teams Project of Guangdong Pearl River Talents Program(2017BT01X137)Foshan Science and Technology Innovation Project(1920001000052)the Foundation of State Key Laboratory of Reactor System Design Technologythe Large Scientific Facility Open Subject of Songshan Lake,Dongguan,Guangdongthe Research Project supported by State Key Lab of Luminescent Materials and DevicesSouth China University of Technology(Skllmd2023-07)the Sponsored Research Project of Corning Incorporated。
文摘Bi-activated photonic materials are promising for various applications in high-capacity telecommunication,tunable laser,and advanced bioimaging and sensing.Although various Bi-doped material candidates have been explored,manufacturing of Bi heavily doped fiber with excellent optical activity remains a long-standing challenge.Herein,a novel viscosity evolutional behavior mediated strategy for manufacturing of Bi-doped active fiber with high dopant solubility is proposed.The intrinsic relation among the evolution of Bi,reaction temperature and viscosity of the glass system is established.Importantly,the effective avenue to prevent the undesired deactivation of Bi during fiber drawing by tuning the temperature dependent viscosity evolution is built.By applying the strategy,for the first time we demonstrate the success in fabrication of heavily doped Bi active fiber.Furthermore,the principal fiber amplifier device is constructed and broadband optical signal amplification is realized.Our findings indicate the effectiveness of the proposed temperature dependent viscosity mediated strategy for developing novel photonic active fiber,and they also demonstrate the great potential for application in the next-generation high-capacity telecommunication system.
基金Project sponsored by the Basic Research Project of the Science and Technology Commission of Shanghai Municipality (Grant No.21JC1400100)the Shanghai Rising-Star Program (Grant No.22QA1400400)+1 种基金the National Natural Science Foundation of China (Grant No.52173031)the Oriental Talent Plan (Leading Talent Program,No.152)。
文摘The self-powered tissue engineering scaffold with good biocompatibility is of great significance for stimulating nerve cell growth.In this study,silk fibroin(SF)-based fibers with regulatable structure and piezoelectric performance are fabricated by dry-spinning and post-treatment.The concentration of SF and calcium ion in spinning dope and the post-treatment affect the conformation transition and crystallinity of SF.As a result,the SF fibers exhibit high piezoelectric coefficient d_(33)(3.24 pm/V)and output voltage(~27 V).Furthermore,these piezoelectric fibers promote the growth of PC-12 cells,demonstrating the promising potential for nerve repair and other energy harvester.
基金the Project Support of NSFC(No.U19B6003-05 and No.52074314)。
文摘A method for in-situ stress measurement via fiber optics was proposed. The method utilizes the relationship between rock mass elastic parameters and in-situ stress. The approach offers the advantage of long-term stress measurements with high spatial resolution and frequency, significantly enhancing the ability to measure in-situ stress. The sensing casing, spirally wrapped with fiber optic, is cemented into the formation to establish a formation sensing nerve. Injecting fluid into the casing generates strain disturbance, establishing the relationship between rock mass properties and treatment pressure.Moreover, an optimization algorithm is established to invert the elastic parameters of formation via fiber optic strains. In the first part of this paper series, we established the theoretical basis for the inverse differential strain analysis method for in-situ stress measurement, which was subsequently verified using an analytical model. This paper is the fundamental basis for the inverse differential strain analysis method.