Optical tweezers technology has the characteristics of noncontact manipulation in three dimensions and steerable separation in solutions,and could be applied to obtain a separated sperm with high quality for intracyto...Optical tweezers technology has the characteristics of noncontact manipulation in three dimensions and steerable separation in solutions,and could be applied to obtain a separated sperm with high quality for intracytoplasmic sperm injection(ICSI).However,the effects of optical tweezers on sperm motility are still unclear.To elucidate the effects on sperm motility for optical tweezers,we systematically investigated the correlation between motility parameters and the parameters of optical tweezers(wavelength,power,trapping duration,and trapping orientation).Under three systems of optical tweezers with different laser wavelengths(1064,850,and 785 nm),the nine motility parameters of free swimming were mainly affected by trapping orientation(vertical/horizontal)and trapping duration.When 850 nm laser and 1064 nm laser are used,vertical trapping significantly reduces sperm free-swimming capability with prolonged exposure time,whereas horizontal trapping exhibits relatively minor interference on sperm motility.Notably,the 785 nm laser does not induce statistically significant changes in key parameters of sperm motility under any experimental conditions(trapping orientation and duration).For the rolling frequency of trapped sperm,horizontal trapping for three wavelengths has a negligible effect compared with vertical trapping,especially for the 785 nm laser.In conclusion,horizontal trapping can preserve sperm motility under low power(below 140mW at 1064 nm,below 100mW at 850nm,below 60mW at 785 nm)and short duration(below 4 min).This trapping duration is suffcient for the separation procedure of single live sperm in ICSI.This study provides critical parameter optimization guidelines for the safe application of optical tweezers technology in reproductive medicine.展开更多
Currently,challenges such as small object size and occlusion lead to a lack of accuracy and robustness in small object detection.Since small objects occupy only a few pixels in an image,the extracted features are limi...Currently,challenges such as small object size and occlusion lead to a lack of accuracy and robustness in small object detection.Since small objects occupy only a few pixels in an image,the extracted features are limited,and mainstream downsampling convolution operations further exacerbate feature loss.Additionally,due to the occlusionprone nature of small objects and their higher sensitivity to localization deviations,conventional Intersection over Union(IoU)loss functions struggle to achieve stable convergence.To address these limitations,LR-Net is proposed for small object detection.Specifically,the proposed Lossless Feature Fusion(LFF)method transfers spatial features into the channel domain while leveraging a hybrid attentionmechanism to focus on critical features,mitigating feature loss caused by downsampling.Furthermore,RSIoU is proposed to enhance the convergence performance of IoU-based losses for small objects.RSIoU corrects the inherent convergence direction issues in SIoU and proposes a penalty term as a Dynamic Focusing Mechanism parameter,enabling it to dynamically emphasize the loss contribution of small object samples.Ultimately,RSIoU significantly improves the convergence performance of the loss function for small objects,particularly under occlusion scenarios.Experiments demonstrate that LR-Net achieves significant improvements across variousmetrics onmultiple datasets compared with YOLOv8n,achieving a 3.7% increase in mean Average Precision(AP)on the VisDrone2019 dataset,along with improvements of 3.3% on the AI-TOD dataset and 1.2% on the COCO dataset.展开更多
Although conventional object detection methods achieve high accuracy through extensively annotated datasets,acquiring such large-scale labeled data remains challenging and cost-prohibitive in numerous real-world appli...Although conventional object detection methods achieve high accuracy through extensively annotated datasets,acquiring such large-scale labeled data remains challenging and cost-prohibitive in numerous real-world applications.Few-shot object detection presents a new research idea that aims to localize and classify objects in images using only limited annotated examples.However,the inherent challenge in few-shot object detection lies in the insufficient sample diversity to fully characterize the sample feature distribution,which consequently impacts model performance.Inspired by contrastive learning principles,we propose an Implicit Feature Contrastive Learning(IFCL)module to address this limitation and augment feature diversity for more robust representational learning.This module generates augmented support sample features in a mixed feature space and implicitly contrasts them with query Region of Interest(RoI)features.This approach facilitates more comprehensive learning of both intra-class feature similarity and inter-class feature diversity,thereby enhancing the model’s object classification and localization capabilities.Extensive experiments on PASCAL VOC show that our method achieves a respective improvement of 3.2%,1.8%,and 2.3%on 10-shot of three Novel Sets compared to the baseline model FPD.展开更多
Blockchain-enabled Internet of Medical Things (BIoMT) has attracted significant attention from academia and healthcare organizations. However, the large amount of medical data involved in BIoMT has also raised concern...Blockchain-enabled Internet of Medical Things (BIoMT) has attracted significant attention from academia and healthcare organizations. However, the large amount of medical data involved in BIoMT has also raised concerns about data security and personal privacy protection. To alleviate these concerns, blind signature technology has emerged as an effective method to solve blindness and unforgeability. Unfortunately, most existing blind signature schemes suffer from the security risk of key leakage. In addition, traditional blind signature schemes are also vulnerable to quantum computing attacks. Therefore, it remains a crucial and ongoing challenge to explore the construction of key-secure, quantum-resistant blind signatures. In this paper, we introduce lattice-based forward-secure blind signature (LFSBS), a lattice-based forward-secure blind signature scheme for medical privacy preservation in BIoMT. LFSBS achieves forward security by constructing a key evolution mechanism using a binary tree structure. This mechanism ensures that even if future encryption keys are leaked, past data can still remain secure. Meanwhile, LFSBS realizes post-quantum security based on the hardness assumption of small integer solution (SIS), making it resistant to potential quantum computing attacks. In addition, we formally define and prove the security of LFSBS in a random oracle model, including blindness and forward-secure unforgeability. Comprehensive performance evaluation shows that LFSBS performs well in terms of computational overhead, with a reduction of 22%–73% compared to previous schemes.展开更多
Optical frequency comb with evenly spaced lines over a broad bandwidth has revolutionized the fields of optical metrology and spectroscopy.Here,we propose a fast interleaved dual-comb spectroscopy with sub-femtometer-...Optical frequency comb with evenly spaced lines over a broad bandwidth has revolutionized the fields of optical metrology and spectroscopy.Here,we propose a fast interleaved dual-comb spectroscopy with sub-femtometer-resolution and absolute frequency,in which two electro-optic frequency combs are swept.Electrically-modulated stabilized laser enables ultrahigh resolution of 0.16 fm(or 20 k Hz in optical frequency)and single-shot measurement in 90 ms.Total 20 million points are recorded spanning 3.2 nm(or 400 GHz)bandwidth,corresponding to a spectral sampling rate of 2.5×10^(8)points/s under Nyquist-limitation.Besides,considering the trade-off between the measurement time and spectral resolution,a fast single-shot measurement is also realized in 1.6 ms with 8 fm(or 1 MHz)resolution.We demonstrate the 25-averaged result with 30.6 d B spectral measurement signal-to-noise ratio(SNR)by reducing the filter bandwidth in demodulation.The results show great prospect for precise measurement with flexibly fast refresh time,high spectral resolution,and high SNR.展开更多
Terminal devices deployed in outdoor environments are facing a thorny problem of power supply.Data and energy integrated network(DEIN)is a promising technology to solve the problem,which simultaneously transfers data ...Terminal devices deployed in outdoor environments are facing a thorny problem of power supply.Data and energy integrated network(DEIN)is a promising technology to solve the problem,which simultaneously transfers data and energy through radio frequency signals.State-of-the-art researches mostly focus on theoretical aspects.By contrast,we provide a complete design and implementation of a fully functioning DEIN system with the support of an unmanned aerial vehicle(UAV).The UAV can be dispatched to areas of interest to remotely recharge batteryless terminals,while collecting essential information from them.Then,the UAV uploads the information to remote base stations.Our system verifies the feasibility of the DEIN in practical applications.展开更多
As an energy converter,electromagnetic linear actuators(EMLAs)have been widely used in industries.Multidisciplinary methodology is a preferred tool for the design and optimization of EMLA.In this paper,a multidiscipli...As an energy converter,electromagnetic linear actuators(EMLAs)have been widely used in industries.Multidisciplinary methodology is a preferred tool for the design and optimization of EMLA.In this paper,a multidisciplinary method was proposed for revealing the influence mechanism of load on EMLA’s loss.The motion trajectory of EMLA is planned through tracking differentiator,an adaptive robust control was adopted to compensate the influence of load on motion trajectory.A control-electromagnetic-mechanical coupling model was established and verified experimentally.The influence laws of load change on EMLA’s loss,loss composition and loss distribution were analyzed quantitatively.The results show that the data error of experiment,and simulation result of input energy,mechanical work,and iron loss is less than 3%.The iron loss accounts for less than 54.9%of the total loss under no-load condition,while the iron loss increases with the increase of load.For iron loss distribution,only the percentage of inner yoke keeps increasing with the increase of load.The composition and distribution of loss are the basis of thermal analysis and design.展开更多
In this research, a modeling and experimental study was conducted to explore the effects of nanoparticle type (aluminum nanoparticles and carbon nanotubes), filler concentration and interactions between the nanopartic...In this research, a modeling and experimental study was conducted to explore the effects of nanoparticle type (aluminum nanoparticles and carbon nanotubes), filler concentration and interactions between the nanoparticle and reinforcing fibers on through-thickness conductivity of nanoparticle/epoxy nanocomposites and nanoparticle/fiber-reinforced multiscale composites. Multiple, notable micromechanical models were evaluated to predict through-thickness thermal conductivity of both composite systems, and then compared to the experimental results. The results showed that filler volume fraction ranges and thermal conductivity differences of the constituent materials for the thermal conductivity ratio (km/kf or kf/km) used in the models can affect the resulting predictions. Certain models were found to be suitable for varying conditions on the thermal conductivity ratio. Finite element models (FEM) were developed to reveal heat transport mechanisms of the resultant nanocomposites and multiscale composites. The nanocomposite design for finite element analysis (FEA) provided close predictions and performed better than the micromechanical models. On the multiscale composite system, predictions were concluded to be dependent upon the FEM design where the interactions between nanoparticles and fibers are critical to accurately determine the through-thickness thermal conductivity.展开更多
The transition towards renewable energy in the marine sector has garnered increasing international focus,with PEMFC(Proton Exchange Membrane Fuel Cell)emerging as a viable low-carbon solution for maritime vessels.This...The transition towards renewable energy in the marine sector has garnered increasing international focus,with PEMFC(Proton Exchange Membrane Fuel Cell)emerging as a viable low-carbon solution for maritime vessels.This technology is not only limited to small vessels,but also is applicable to the auxiliary power systems of larger ships.In this paper,a hybrid control scheme based on optimization algorithms and observer are presented.This strategy is designed to enhance the safety and efficiency of stack’s operation during navigation.Within the control system,a sliding mode observer monitors system perturbations,ensuring optimal controller performance.The control strategy employs a non-singular fast terminal sliding surface for the controller,integrating a fuzzy logic and particle swarm optimization to tune the sliding mode gain and dynamically regulate output,thereby enhancing system efficiency and minimizing energy consumption.Results indicate that the newly developed control methodology significantly boosts both the efficiency and dependability of marine PEMFC stack.展开更多
We demonstrate a high-resolution mid-infrared(MIR)dual-comb interferometer(DCI)using spectral interleaving.By generating electro-optic frequency combs(EOFCs)at 1550 nm via a dual-drive Mach-Zehnder modulator(DD-MZM)an...We demonstrate a high-resolution mid-infrared(MIR)dual-comb interferometer(DCI)using spectral interleaving.By generating electro-optic frequency combs(EOFCs)at 1550 nm via a dual-drive Mach-Zehnder modulator(DD-MZM)and employing injection locking to create a linearly swept lightwave spanning 18 GHz,we achieve gapless spectral interleaving.This swept lightwave serves as the seed for dual EOFCs with a 1 MHz repetition rate difference,which are subsequently converted to the MIR region(3.3μm)via difference frequency generation(DFG).Experimental results demonstrate a dual-comb spectrum spanning 486 GHz with a 100 MHz resolution,validated by direct detection and demodulation.展开更多
Dual-comb hyperspectral digital holography(DC-HSDH)is an emerging technique employing two optical frequency combs with slightly different repetition frequencies for hyperspectral holographic imaging.Leveraging the uni...Dual-comb hyperspectral digital holography(DC-HSDH)is an emerging technique employing two optical frequency combs with slightly different repetition frequencies for hyperspectral holographic imaging.Leveraging the unique capabilities of dual-comb interferometry(DCI),DC-HSDH enables the acquisition of phase maps and amplitude maps for multiple wavelengths in parallel,showcasing advantages in imaging speed and robustness.This study introduces a simplified DC-HSDH system based on spatial heterodyne DCI.It reduces the number of required optical devices in comparison to conventional DC-HSDH systems,leading to a streamlined system structure,reduced electric power consumption,and enhanced optical power efficiency.Additionally,it effectively improves the space-time bandwidth product by doubling the temporal bandwidth efficiency.Experiments were performed to validate the system.The proposed system successfully retrieved the three-dimensional profile of a stepped reflector without ambiguity,and the transmission spectrum of an absorbing gas was obtained simultaneously.展开更多
We propose a method for reconstructing the distributed forward state of polarization(SOP)in single-mode fibers(SMFs)to solve the problem of an unpredictable blind box of SOP evolution in many applications such as fibe...We propose a method for reconstructing the distributed forward state of polarization(SOP)in single-mode fibers(SMFs)to solve the problem of an unpredictable blind box of SOP evolution in many applications such as fiber-optic parametric amplification systems.Using polarization-sensitive optical frequency domain reflectometry(POFDR)and a quaternion-based model to describe polarization changes,our approach achieves high spatial resolution and precision.By an improved iterative fitting algorithm,the mean square error(MSE)of forward SOP reconstruction for approximately 100 consecutive measurement points was reduced to below 0.1%.This method enables visualization of SOP dynamics along the fiber,offering critical insights for polarization-dependent systems.展开更多
The surfaces of brittle materials are susceptible to defects such as scratches,cracks,and chipping during con-ventional grinding processes,which significantly compromise surface quality and service performance.A flexi...The surfaces of brittle materials are susceptible to defects such as scratches,cracks,and chipping during con-ventional grinding processes,which significantly compromise surface quality and service performance.A flexible ball-end body-armor-like abrasive tool(BAAT)can effectively remove micro-convex peaks from the surfaces of brittle materials by employing a high tangential grinding force and a low normal grinding force,thereby achieving nano-level surface roughness and ultra-smooth mirror finishes.However,the surface contact me-chanism,pressure distribution pattern,and grinding force behavior between BAAT and workpiece remain in-adequately understood.This study examines the mechanism of liquid film formation and the distribution pattern of elastohydrodynamic pressure in high-shear and low-pressure grinding areas,drawing on the theories of elastohydrodynamic lubrication,non-Newtonian fluid dynamics,and material mechanics.A high-shear low-pressure grinding force model,which incorporates elastohydrodynamic liquid film thickness and abrasive grain size,was developed.The effects of the main grinding parameters(normal load,spindle rotational speed,and abrasive grain size)on the tangential grinding force were investigated through the processing of lithium niobate crystals using an intelligent precision-grinding system.The experimental results indicated that the relative error between the predicted and experimental values was 10.74%,thereby confirming the accuracy of the grinding force model.This study advances the understanding of elastohydrodynamic lubrication mechanisms in abrasive machining and provides a crucial theoretical foundation for the application of flexible ball-end BAAT.展开更多
The integration of high-speed optical communication and distributed sensing could bring intelligent functionalities to ubiquitous optical fibre networks,such as urban structure imaging,ocean seismic detection,and safe...The integration of high-speed optical communication and distributed sensing could bring intelligent functionalities to ubiquitous optical fibre networks,such as urban structure imaging,ocean seismic detection,and safety monitoring of underground embedded pipelines.This work demonstrates a scheme of integrated sensing and communication in an optical fibre(ISAC-OF)using the same wavelength channel for simultaneous data transmission and distributed vibration sensing.The scheme not only extends the intelligent functionality for optical fibre communication system,but also improves its transmission performance.A periodic linear frequency modulation(LFM)light is generated to act as the optical carrier and sensing probe in PAM4 signal transmission and phase-sensitive optical time-domain reflectometry(Φ-OTDR),respectively.After a 24.5 km fibre transmission,the forward PAM4 signal and the carriercorrespondence Rayleigh backscattering signal are detected and demodulated.Experimental results show that the integrated solution achieves better transmission performance(~1.3 dB improvement)and a larger launching power(7 dB enhancement)at a 56 Gbit/s bit rate compared to a conventional PAM4 signal transmission.Meanwhile,a 4m spatial resolution,4.32-nε/√Hz strain resolution,and over 21 kHz frequency response for the vibration sensing are obtained.The proposed solution offers a new path to further explore the potential of existing or future fibre-optic networks by the convergence of data transmission and status sensing.In addition,such a scheme of using shared spectrum in communication and distributed optical fibre sensing may be used to measure non-linear parameters in coherent optical communications,offering possible benefits for data transmission.展开更多
Accurate spectral measurement and wavelength determination are fundamental and vital for many fields.A compact spectrum analyzer with high performance is expected to meet the growing requirements,and speckle-based spe...Accurate spectral measurement and wavelength determination are fundamental and vital for many fields.A compact spectrum analyzer with high performance is expected to meet the growing requirements,and speckle-based spectrum analyzer is a potential solution.The basic principle is based on using the random medium to establish a speckle-to-wavelength mapping relationship for spectrum reconstruction.This article introduces current speckle-based spectrum analyzers with different schemes and reviews recent advances in this field.Besides,some applications by using speckle-based spectrum analyzers are also introduced.Finally,the existing challenges and the future prospects of using speckle for spectrum recovery are discussed.展开更多
Backscattered lightwaves from an optical fibre are used to realise distributed fibre optic sensing(DFOS)systems for measuring various parameters.Rayleigh,Brillouin,and Raman backscattering provide different sensitivit...Backscattered lightwaves from an optical fibre are used to realise distributed fibre optic sensing(DFOS)systems for measuring various parameters.Rayleigh,Brillouin,and Raman backscattering provide different sensitivities to different measurands and have garnered the attention of researchers.A system combining the three principles above can effectively separate the measured strain and temperature completely as well as provide measurements of both dynamic and static parameters.However,the combined system is extremely complicated if the three systems are independent of each other.Hence,we propose a single-end hybrid DFOS system that uses two successive pulses to realise the Brillouin amplification of Rayleigh backscattering lightwaves for combining Rayleigh and Brillouin systems.A 3-bit pulse-coding method is employed to demodulate the Raman scattering of the two pulses to integrate Raman optical time-domain reflectometry into the hybrid system.Using this hybrid scheme,a simultaneous measurement of multiple parameters is realised,and a favourable measurement accuracy is achieved.展开更多
Physically vitrifying amorphous single-element metal requires ultrahigh cooling rates,which are still unachievable for most of the closest-packed metals.Here,we report a facile chemical synthetic strategy for single-e...Physically vitrifying amorphous single-element metal requires ultrahigh cooling rates,which are still unachievable for most of the closest-packed metals.Here,we report a facile chemical synthetic strategy for single-element amorphous palladium nanoparticles with a purity of 99.35 at.%±0.23 at.%from palladium–silicon liquid droplets.In-situ transmission electron microscopy directly detected the solidification of palladium and the separation of silicon.Further hydrogen absorption experiment showed that the amorphous palladium expanded little upon hydrogen uptake,exhibiting a great potential application for hydrogen separation.Our results provide insight into the formation of amorphous metal at nanoscale.展开更多
Current therapies for systemic lupus erythematosus that target a particular factor or cell type exhibit limited effectiveness.To address this limitation,our focus was on CD132,a subunit common to six inflammatory fact...Current therapies for systemic lupus erythematosus that target a particular factor or cell type exhibit limited effectiveness.To address this limitation,our focus was on CD132,a subunit common to six inflammatory factor receptors implicated in SLE.Our study revealed heightened CD132 expression in SLE patients’lymphocytes,contributing to the production of pro-inflammatory cytokines and immunoglobulins.We developed a novel humanized anti-CD132 monoclonal antibody,named as 2D4.2D4 efficiently blocked IL-21 and IL-15,with limited effectiveness against IL-2,thereby suppressing T and B cells without disrupting immune tolerance.In the mouse immunization model,2D4 virtually inhibited T cell-dependent,antigen-specific B-cell response.In lupus murine models,2D4 mitigated inflammation by suppressing multiple pro-inflammatory cytokines and anti-dsDNA antibody titers,also diminishing proteinuria and glomerulonephritis.Compared to Belimumab,2D4 exhibited superior efficacy in ameliorating the inflammatory state and preserving renal function.Moreover,2D4 exhibited the ability to inhibit the production of pro-inflammatory factors and autoantibodies in PBMCs from individuals with SLE,highlighting its therapeutic potential for SLE individuals.Potent,2D4 has the potential to significantly improve clinical outcomes in SLE and other complex autoimmune disorders.展开更多
基金supported by the Natural Science Foundation of Anhui Province in China(2508085MF166)Research Fund of Anhui Institute of Translational Medicine(2024zh-03)+2 种基金Key Scientific Research Foundation of Education Department of Anhui Province(2023AH040083)National Natural Science Foundation of China(12404353)Cultivation Project of Training Young and Middle-aged Teachers in Universities of Anhui Province(DTR2023013).
文摘Optical tweezers technology has the characteristics of noncontact manipulation in three dimensions and steerable separation in solutions,and could be applied to obtain a separated sperm with high quality for intracytoplasmic sperm injection(ICSI).However,the effects of optical tweezers on sperm motility are still unclear.To elucidate the effects on sperm motility for optical tweezers,we systematically investigated the correlation between motility parameters and the parameters of optical tweezers(wavelength,power,trapping duration,and trapping orientation).Under three systems of optical tweezers with different laser wavelengths(1064,850,and 785 nm),the nine motility parameters of free swimming were mainly affected by trapping orientation(vertical/horizontal)and trapping duration.When 850 nm laser and 1064 nm laser are used,vertical trapping significantly reduces sperm free-swimming capability with prolonged exposure time,whereas horizontal trapping exhibits relatively minor interference on sperm motility.Notably,the 785 nm laser does not induce statistically significant changes in key parameters of sperm motility under any experimental conditions(trapping orientation and duration).For the rolling frequency of trapped sperm,horizontal trapping for three wavelengths has a negligible effect compared with vertical trapping,especially for the 785 nm laser.In conclusion,horizontal trapping can preserve sperm motility under low power(below 140mW at 1064 nm,below 100mW at 850nm,below 60mW at 785 nm)and short duration(below 4 min).This trapping duration is suffcient for the separation procedure of single live sperm in ICSI.This study provides critical parameter optimization guidelines for the safe application of optical tweezers technology in reproductive medicine.
基金supported by Chongqing Municipal Commission of Housing and Urban-Rural Development(Grant No.CKZ2024-87)China Chongqing Municipal Science and Technology Bureau(Grant No.2024TIAD-CYKJCXX0121).
文摘Currently,challenges such as small object size and occlusion lead to a lack of accuracy and robustness in small object detection.Since small objects occupy only a few pixels in an image,the extracted features are limited,and mainstream downsampling convolution operations further exacerbate feature loss.Additionally,due to the occlusionprone nature of small objects and their higher sensitivity to localization deviations,conventional Intersection over Union(IoU)loss functions struggle to achieve stable convergence.To address these limitations,LR-Net is proposed for small object detection.Specifically,the proposed Lossless Feature Fusion(LFF)method transfers spatial features into the channel domain while leveraging a hybrid attentionmechanism to focus on critical features,mitigating feature loss caused by downsampling.Furthermore,RSIoU is proposed to enhance the convergence performance of IoU-based losses for small objects.RSIoU corrects the inherent convergence direction issues in SIoU and proposes a penalty term as a Dynamic Focusing Mechanism parameter,enabling it to dynamically emphasize the loss contribution of small object samples.Ultimately,RSIoU significantly improves the convergence performance of the loss function for small objects,particularly under occlusion scenarios.Experiments demonstrate that LR-Net achieves significant improvements across variousmetrics onmultiple datasets compared with YOLOv8n,achieving a 3.7% increase in mean Average Precision(AP)on the VisDrone2019 dataset,along with improvements of 3.3% on the AI-TOD dataset and 1.2% on the COCO dataset.
基金funded by the China Chongqing Municipal Science and Technology Bureau,grant numbers CSTB2024TIAD-CYKJCXX0009,CSTB2024NSCQ-LZX0043,CSTB2022NSCQ-MSX0288Chongqing Municipal Commission of Housing and Urban-Rural Development,grant number CKZ2024-87+3 种基金the Chongqing University of Technology Graduate Education High-Quality Development Project,grant number gzlsz202401the Chongqing University of Technology—Chongqing LINGLUE Technology Co.,Ltd.Electronic Information(Artificial Intelligence)Graduate Joint Training Basethe Postgraduate Education and Teaching Reform Research Project in Chongqing,grant number yjg213116the Chongqing University of Technology-CISDI Chongqing Information Technology Co.,Ltd.Computer Technology Graduate Joint Training Base.
文摘Although conventional object detection methods achieve high accuracy through extensively annotated datasets,acquiring such large-scale labeled data remains challenging and cost-prohibitive in numerous real-world applications.Few-shot object detection presents a new research idea that aims to localize and classify objects in images using only limited annotated examples.However,the inherent challenge in few-shot object detection lies in the insufficient sample diversity to fully characterize the sample feature distribution,which consequently impacts model performance.Inspired by contrastive learning principles,we propose an Implicit Feature Contrastive Learning(IFCL)module to address this limitation and augment feature diversity for more robust representational learning.This module generates augmented support sample features in a mixed feature space and implicitly contrasts them with query Region of Interest(RoI)features.This approach facilitates more comprehensive learning of both intra-class feature similarity and inter-class feature diversity,thereby enhancing the model’s object classification and localization capabilities.Extensive experiments on PASCAL VOC show that our method achieves a respective improvement of 3.2%,1.8%,and 2.3%on 10-shot of three Novel Sets compared to the baseline model FPD.
基金funded by the Yunnan Key Laboratory of Blockchain Application Technology(202105AG070005,202305AG340008)&YNB202301,NSFC(Grant Nos.72293583,72293580,62476007,62176273,62271234)the Open Foundation of State Key Laboratory of Networking and Switching Technology(Beijing University of Posts and Telecommunications)(SKLNST-2024-1-06)+2 种基金the Project of Science and Technology Major Project of Yunnan Province(202302AF080006)Open Foundation of State Key Laboratory of Public Big Data(Guizhou University)under Grant No.PBD2022-16Double First-Class Project for Collaborative Innovation Achievements inDisciplines Construction in Heilongjiang Province under Grant No.GXCG2022-054.
文摘Blockchain-enabled Internet of Medical Things (BIoMT) has attracted significant attention from academia and healthcare organizations. However, the large amount of medical data involved in BIoMT has also raised concerns about data security and personal privacy protection. To alleviate these concerns, blind signature technology has emerged as an effective method to solve blindness and unforgeability. Unfortunately, most existing blind signature schemes suffer from the security risk of key leakage. In addition, traditional blind signature schemes are also vulnerable to quantum computing attacks. Therefore, it remains a crucial and ongoing challenge to explore the construction of key-secure, quantum-resistant blind signatures. In this paper, we introduce lattice-based forward-secure blind signature (LFSBS), a lattice-based forward-secure blind signature scheme for medical privacy preservation in BIoMT. LFSBS achieves forward security by constructing a key evolution mechanism using a binary tree structure. This mechanism ensures that even if future encryption keys are leaked, past data can still remain secure. Meanwhile, LFSBS realizes post-quantum security based on the hardness assumption of small integer solution (SIS), making it resistant to potential quantum computing attacks. In addition, we formally define and prove the security of LFSBS in a random oracle model, including blindness and forward-secure unforgeability. Comprehensive performance evaluation shows that LFSBS performs well in terms of computational overhead, with a reduction of 22%–73% compared to previous schemes.
基金funding from National Natural Science Foundation of China(NSFC)under Grant Nos.61775132,61735015,61620106015supported by the Major Key Project of Peng Cheng Laboratory(PCL)。
文摘Optical frequency comb with evenly spaced lines over a broad bandwidth has revolutionized the fields of optical metrology and spectroscopy.Here,we propose a fast interleaved dual-comb spectroscopy with sub-femtometer-resolution and absolute frequency,in which two electro-optic frequency combs are swept.Electrically-modulated stabilized laser enables ultrahigh resolution of 0.16 fm(or 20 k Hz in optical frequency)and single-shot measurement in 90 ms.Total 20 million points are recorded spanning 3.2 nm(or 400 GHz)bandwidth,corresponding to a spectral sampling rate of 2.5×10^(8)points/s under Nyquist-limitation.Besides,considering the trade-off between the measurement time and spectral resolution,a fast single-shot measurement is also realized in 1.6 ms with 8 fm(or 1 MHz)resolution.We demonstrate the 25-averaged result with 30.6 d B spectral measurement signal-to-noise ratio(SNR)by reducing the filter bandwidth in demodulation.The results show great prospect for precise measurement with flexibly fast refresh time,high spectral resolution,and high SNR.
基金partly funded by Natural Science Foundation of China(No.61971102 and 62132004)Sichuan Science and Technology Program(No.22QYCX0168)the Municipal Government of Quzhou(Grant No.2021D003)。
文摘Terminal devices deployed in outdoor environments are facing a thorny problem of power supply.Data and energy integrated network(DEIN)is a promising technology to solve the problem,which simultaneously transfers data and energy through radio frequency signals.State-of-the-art researches mostly focus on theoretical aspects.By contrast,we provide a complete design and implementation of a fully functioning DEIN system with the support of an unmanned aerial vehicle(UAV).The UAV can be dispatched to areas of interest to remotely recharge batteryless terminals,while collecting essential information from them.Then,the UAV uploads the information to remote base stations.Our system verifies the feasibility of the DEIN in practical applications.
基金funded by the National Natural Science Foundation of China,Grant Nos.51905319,51975341,51875326the National Key Research and Development Project,China under Grant 2017YFB0102004the Shandong Provincial Natural Science Foundation,China under Grant ZR2019MEE049.
文摘As an energy converter,electromagnetic linear actuators(EMLAs)have been widely used in industries.Multidisciplinary methodology is a preferred tool for the design and optimization of EMLA.In this paper,a multidisciplinary method was proposed for revealing the influence mechanism of load on EMLA’s loss.The motion trajectory of EMLA is planned through tracking differentiator,an adaptive robust control was adopted to compensate the influence of load on motion trajectory.A control-electromagnetic-mechanical coupling model was established and verified experimentally.The influence laws of load change on EMLA’s loss,loss composition and loss distribution were analyzed quantitatively.The results show that the data error of experiment,and simulation result of input energy,mechanical work,and iron loss is less than 3%.The iron loss accounts for less than 54.9%of the total loss under no-load condition,while the iron loss increases with the increase of load.For iron loss distribution,only the percentage of inner yoke keeps increasing with the increase of load.The composition and distribution of loss are the basis of thermal analysis and design.
文摘In this research, a modeling and experimental study was conducted to explore the effects of nanoparticle type (aluminum nanoparticles and carbon nanotubes), filler concentration and interactions between the nanoparticle and reinforcing fibers on through-thickness conductivity of nanoparticle/epoxy nanocomposites and nanoparticle/fiber-reinforced multiscale composites. Multiple, notable micromechanical models were evaluated to predict through-thickness thermal conductivity of both composite systems, and then compared to the experimental results. The results showed that filler volume fraction ranges and thermal conductivity differences of the constituent materials for the thermal conductivity ratio (km/kf or kf/km) used in the models can affect the resulting predictions. Certain models were found to be suitable for varying conditions on the thermal conductivity ratio. Finite element models (FEM) were developed to reveal heat transport mechanisms of the resultant nanocomposites and multiscale composites. The nanocomposite design for finite element analysis (FEA) provided close predictions and performed better than the micromechanical models. On the multiscale composite system, predictions were concluded to be dependent upon the FEM design where the interactions between nanoparticles and fibers are critical to accurately determine the through-thickness thermal conductivity.
基金support from the National Natural Science Foundation of China(22179054)Ministry of Science and Technology of the People’s Republic of China(G2022014065L)the Innovation Support Program of Science and Technology Program of Jiangsu Province(SBZ2023080107).
文摘The transition towards renewable energy in the marine sector has garnered increasing international focus,with PEMFC(Proton Exchange Membrane Fuel Cell)emerging as a viable low-carbon solution for maritime vessels.This technology is not only limited to small vessels,but also is applicable to the auxiliary power systems of larger ships.In this paper,a hybrid control scheme based on optimization algorithms and observer are presented.This strategy is designed to enhance the safety and efficiency of stack’s operation during navigation.Within the control system,a sliding mode observer monitors system perturbations,ensuring optimal controller performance.The control strategy employs a non-singular fast terminal sliding surface for the controller,integrating a fuzzy logic and particle swarm optimization to tune the sliding mode gain and dynamically regulate output,thereby enhancing system efficiency and minimizing energy consumption.Results indicate that the newly developed control methodology significantly boosts both the efficiency and dependability of marine PEMFC stack.
基金supported by the National Natural Science Foundation of China(No.62275151)。
文摘We demonstrate a high-resolution mid-infrared(MIR)dual-comb interferometer(DCI)using spectral interleaving.By generating electro-optic frequency combs(EOFCs)at 1550 nm via a dual-drive Mach-Zehnder modulator(DD-MZM)and employing injection locking to create a linearly swept lightwave spanning 18 GHz,we achieve gapless spectral interleaving.This swept lightwave serves as the seed for dual EOFCs with a 1 MHz repetition rate difference,which are subsequently converted to the MIR region(3.3μm)via difference frequency generation(DFG).Experimental results demonstrate a dual-comb spectrum spanning 486 GHz with a 100 MHz resolution,validated by direct detection and demodulation.
基金supported by the National Natural Science Foundation of China(No.62275151)。
文摘Dual-comb hyperspectral digital holography(DC-HSDH)is an emerging technique employing two optical frequency combs with slightly different repetition frequencies for hyperspectral holographic imaging.Leveraging the unique capabilities of dual-comb interferometry(DCI),DC-HSDH enables the acquisition of phase maps and amplitude maps for multiple wavelengths in parallel,showcasing advantages in imaging speed and robustness.This study introduces a simplified DC-HSDH system based on spatial heterodyne DCI.It reduces the number of required optical devices in comparison to conventional DC-HSDH systems,leading to a streamlined system structure,reduced electric power consumption,and enhanced optical power efficiency.Additionally,it effectively improves the space-time bandwidth product by doubling the temporal bandwidth efficiency.Experiments were performed to validate the system.The proposed system successfully retrieved the three-dimensional profile of a stepped reflector without ambiguity,and the transmission spectrum of an absorbing gas was obtained simultaneously.
基金supported by the National Key R&D Program of China(No.2023YFB2804900)the National Natural Science Foundation of China(Nos.62275151 and 62405178)。
文摘We propose a method for reconstructing the distributed forward state of polarization(SOP)in single-mode fibers(SMFs)to solve the problem of an unpredictable blind box of SOP evolution in many applications such as fiber-optic parametric amplification systems.Using polarization-sensitive optical frequency domain reflectometry(POFDR)and a quaternion-based model to describe polarization changes,our approach achieves high spatial resolution and precision.By an improved iterative fitting algorithm,the mean square error(MSE)of forward SOP reconstruction for approximately 100 consecutive measurement points was reduced to below 0.1%.This method enables visualization of SOP dynamics along the fiber,offering critical insights for polarization-dependent systems.
基金Supported by National Natural Science Foundation of China(Grant Nos.52575516,51875329)Taishan Scholar Special Foundation of Shandong Province(Grant Nos.tstp20240826,tsqn201812064)+2 种基金Shandong Provincial Natural Science Foundation(Grant No.ZR2023ME112)Key Research and Development Project of the Ningxia Hui Autonomous Region(Grant No.2024BEE02019)Innovation Capacity Improvement Programme for High-tech SMEs of Shandong Province(Grant Nos.2022TSGC1333,2022TSGC1261).
文摘The surfaces of brittle materials are susceptible to defects such as scratches,cracks,and chipping during con-ventional grinding processes,which significantly compromise surface quality and service performance.A flexible ball-end body-armor-like abrasive tool(BAAT)can effectively remove micro-convex peaks from the surfaces of brittle materials by employing a high tangential grinding force and a low normal grinding force,thereby achieving nano-level surface roughness and ultra-smooth mirror finishes.However,the surface contact me-chanism,pressure distribution pattern,and grinding force behavior between BAAT and workpiece remain in-adequately understood.This study examines the mechanism of liquid film formation and the distribution pattern of elastohydrodynamic pressure in high-shear and low-pressure grinding areas,drawing on the theories of elastohydrodynamic lubrication,non-Newtonian fluid dynamics,and material mechanics.A high-shear low-pressure grinding force model,which incorporates elastohydrodynamic liquid film thickness and abrasive grain size,was developed.The effects of the main grinding parameters(normal load,spindle rotational speed,and abrasive grain size)on the tangential grinding force were investigated through the processing of lithium niobate crystals using an intelligent precision-grinding system.The experimental results indicated that the relative error between the predicted and experimental values was 10.74%,thereby confirming the accuracy of the grinding force model.This study advances the understanding of elastohydrodynamic lubrication mechanisms in abrasive machining and provides a crucial theoretical foundation for the application of flexible ball-end BAAT.
基金supported by the National Key Research and Development Program of China(2019YFB1803500)the National Natural Science Foundation of China(NSFC)(61735015,61860206006,62205275,62005228).
文摘The integration of high-speed optical communication and distributed sensing could bring intelligent functionalities to ubiquitous optical fibre networks,such as urban structure imaging,ocean seismic detection,and safety monitoring of underground embedded pipelines.This work demonstrates a scheme of integrated sensing and communication in an optical fibre(ISAC-OF)using the same wavelength channel for simultaneous data transmission and distributed vibration sensing.The scheme not only extends the intelligent functionality for optical fibre communication system,but also improves its transmission performance.A periodic linear frequency modulation(LFM)light is generated to act as the optical carrier and sensing probe in PAM4 signal transmission and phase-sensitive optical time-domain reflectometry(Φ-OTDR),respectively.After a 24.5 km fibre transmission,the forward PAM4 signal and the carriercorrespondence Rayleigh backscattering signal are detected and demodulated.Experimental results show that the integrated solution achieves better transmission performance(~1.3 dB improvement)and a larger launching power(7 dB enhancement)at a 56 Gbit/s bit rate compared to a conventional PAM4 signal transmission.Meanwhile,a 4m spatial resolution,4.32-nε/√Hz strain resolution,and over 21 kHz frequency response for the vibration sensing are obtained.The proposed solution offers a new path to further explore the potential of existing or future fibre-optic networks by the convergence of data transmission and status sensing.In addition,such a scheme of using shared spectrum in communication and distributed optical fibre sensing may be used to measure non-linear parameters in coherent optical communications,offering possible benefits for data transmission.
基金supported by the National Natural Science Foundation of China(NSFC)(Grant Nos.61775132,61735015,and 61620106015).
文摘Accurate spectral measurement and wavelength determination are fundamental and vital for many fields.A compact spectrum analyzer with high performance is expected to meet the growing requirements,and speckle-based spectrum analyzer is a potential solution.The basic principle is based on using the random medium to establish a speckle-to-wavelength mapping relationship for spectrum reconstruction.This article introduces current speckle-based spectrum analyzers with different schemes and reviews recent advances in this field.Besides,some applications by using speckle-based spectrum analyzers are also introduced.Finally,the existing challenges and the future prospects of using speckle for spectrum recovery are discussed.
基金funding from the National Natural Science Foundation of China(NSFC)under grant numbers 61735015,62275151the Major Key Project of PCL.
文摘Backscattered lightwaves from an optical fibre are used to realise distributed fibre optic sensing(DFOS)systems for measuring various parameters.Rayleigh,Brillouin,and Raman backscattering provide different sensitivities to different measurands and have garnered the attention of researchers.A system combining the three principles above can effectively separate the measured strain and temperature completely as well as provide measurements of both dynamic and static parameters.However,the combined system is extremely complicated if the three systems are independent of each other.Hence,we propose a single-end hybrid DFOS system that uses two successive pulses to realise the Brillouin amplification of Rayleigh backscattering lightwaves for combining Rayleigh and Brillouin systems.A 3-bit pulse-coding method is employed to demodulate the Raman scattering of the two pulses to integrate Raman optical time-domain reflectometry into the hybrid system.Using this hybrid scheme,a simultaneous measurement of multiple parameters is realised,and a favourable measurement accuracy is achieved.
基金supported by the National Natural Science Foundation of China(Nos.51602143,51702150,11874194,11774142,and 11874194)the Science and Technology Innovation Committee Foundation of Shenzhen(Nos.KQTD2016022619565991,JCYJ20200109141205978,and ZDSYS20141118160434515)+1 种基金the Natural Science Foundation of Guangdong Province(No.2015A030308001)the Leading Talents of Guangdong Province Program(No.00201517)。
文摘Physically vitrifying amorphous single-element metal requires ultrahigh cooling rates,which are still unachievable for most of the closest-packed metals.Here,we report a facile chemical synthetic strategy for single-element amorphous palladium nanoparticles with a purity of 99.35 at.%±0.23 at.%from palladium–silicon liquid droplets.In-situ transmission electron microscopy directly detected the solidification of palladium and the separation of silicon.Further hydrogen absorption experiment showed that the amorphous palladium expanded little upon hydrogen uptake,exhibiting a great potential application for hydrogen separation.Our results provide insight into the formation of amorphous metal at nanoscale.
基金supported by following fundings:the National Key R&D Program of China(No.2022YFC3601800)the CAMS Innovation Fund for Medical Sciences(No.2021-I2M-1-059)+4 种基金non-profit Central Research Institute Fund of Chinese Academy of Medical Sciences(No.2021-RC320-001,No.2020-RC320-003)the Special Program of National Natural Science Foundation of China(NO.32141004)the Special Research Fund for Central Universities,Peking Union Medical College(No.3332023075)Natural Science Foundation of Jiangsu Province(No.BK20230130)National Natural Science Foundation of China(No.82302982).
文摘Current therapies for systemic lupus erythematosus that target a particular factor or cell type exhibit limited effectiveness.To address this limitation,our focus was on CD132,a subunit common to six inflammatory factor receptors implicated in SLE.Our study revealed heightened CD132 expression in SLE patients’lymphocytes,contributing to the production of pro-inflammatory cytokines and immunoglobulins.We developed a novel humanized anti-CD132 monoclonal antibody,named as 2D4.2D4 efficiently blocked IL-21 and IL-15,with limited effectiveness against IL-2,thereby suppressing T and B cells without disrupting immune tolerance.In the mouse immunization model,2D4 virtually inhibited T cell-dependent,antigen-specific B-cell response.In lupus murine models,2D4 mitigated inflammation by suppressing multiple pro-inflammatory cytokines and anti-dsDNA antibody titers,also diminishing proteinuria and glomerulonephritis.Compared to Belimumab,2D4 exhibited superior efficacy in ameliorating the inflammatory state and preserving renal function.Moreover,2D4 exhibited the ability to inhibit the production of pro-inflammatory factors and autoantibodies in PBMCs from individuals with SLE,highlighting its therapeutic potential for SLE individuals.Potent,2D4 has the potential to significantly improve clinical outcomes in SLE and other complex autoimmune disorders.
