Self-trapped excitons(STEs),known for their unique radiative properties,have been harnessed in diverse photonic devices;however,their comprehensive understanding and manipulation remain elusive.In this study,we presen...Self-trapped excitons(STEs),known for their unique radiative properties,have been harnessed in diverse photonic devices;however,their comprehensive understanding and manipulation remain elusive.In this study,we present novel experimental and theoretical evidence revealing the hybrid nature and optical tunability of STE state in Cs_(2)Ag_(0.4)Na_(0.6)InCl_(6).The detection of the Fano resonance in laser energy-dependent Raman and photoluminescence spectra indicates the emergence of an exciton-phonon hybrid state,arising from robust quantum interference between the discrete phonon and continuum exciton states.Moreover,we demonstrate continuous tuning of this hybrid state with the energy and intensity of the laser field.These findings lay the foundation for a comprehensive understanding of the nature of STE and their potential for state control.展开更多
In this paper,a practical method named linear active disturbance rejection control(LADRC)with adaptive tuning is proposed for attitude control of small-scale unmanned helicopter.The proposed method accounts for both e...In this paper,a practical method named linear active disturbance rejection control(LADRC)with adaptive tuning is proposed for attitude control of small-scale unmanned helicopter.The proposed method accounts for both external disturbances and internal dynamic uncertainties,as well as parameter deviations arising from parameter uncertainty,while maintaining a relatively small number of adjustable parameters.Furthermore,it addresses the limitation that conventional active disturbance rejection control methods cannot be rigorously analyzed for stability.The total disturbance of unmanned helicopter is estimated and compensated by designed LADRC.The introduction of adaptive control realizes online parameter tuning,which eliminates parameter deviation and further improves control precision.Moreover,it also provides a novel idea to prove the stability of controller,so that it can be analyzed by Lyapunov function.Finally,the anti-disturbance performance and effectiveness of proposed method are verified by numerical simulation.展开更多
In this paper,a fast step heterodyne light-induced thermoelastic spectroscopy(SH-LITES)sensor using a high-frequency quartz tuning fork(QTF)with resonant frequency of~100 kHz is reported for the first time.The theoret...In this paper,a fast step heterodyne light-induced thermoelastic spectroscopy(SH-LITES)sensor using a high-frequency quartz tuning fork(QTF)with resonant frequency of~100 kHz is reported for the first time.The theoretical principle of heterodyne LITES(H-LITES)signal generation is analyzed firstly,and an acetylene(C_(2)H_(2))H-LITES sensor is established to verify its performance.Experimental comparisons between the high-frequency QTF and a standard commercial QTF with resonant frequency of~32.768 kHz reveal that the high-frequency QTF exhibits a tenfold faster response time.Specifically,the H-LITES sensor with this QTF achieves a 33 ms measurement cycle,90%shorter than commercial counterparts.Furthermore,The SH-LITES technique is proposed to further shorten the scanning time to 15 ms,which achieves the shortest LITES measurement time known to date.To demonstrate its advantages in dynamic gas detection,an H_(2)O-LITES system integrating both QTF types is constructed for real-time monitoring of H_(2)O concentration during different respiration patterns.Comparative measurements show that the SH-LITES more accurately captures dynamic H_(2)O concentration fluctuations during respiration,outperforming the commercial QTF-based H-LITES sensor in rapid response scenarios.展开更多
We present a gain adaptive tuning method for fiber Raman amplifier(FRA) using two-stage neural networks(NNs) and double weights updates. After training the connection weights of two-stage NNs separately in training ph...We present a gain adaptive tuning method for fiber Raman amplifier(FRA) using two-stage neural networks(NNs) and double weights updates. After training the connection weights of two-stage NNs separately in training phase, the connection weights of the unified NN are updated again in verification phase according to error between the predicted and target gains to eliminate the inherent error of the NNs. The simulation results show that the mean of root mean square error(RMSE) and maximum error of gains are 0.131 d B and 0.281 d B, respectively. It shows that the method can realize adaptive adjustment function of FRA gain with high accuracy.展开更多
In this paper,a novel four-prong quartz tuning fork(QTF)was designed with enlarged deformation area,large prong gap,and low resonant frequency to improve its performance in laser spectroscopy sensing.A theoretical sim...In this paper,a novel four-prong quartz tuning fork(QTF)was designed with enlarged deformation area,large prong gap,and low resonant frequency to improve its performance in laser spectroscopy sensing.A theoretical simulation model was established to optimize the design of the QTF structure.In the simulation of quartz-enhanced photoacoustic spectroscopy(QEPAS)technology,the maximum stress and the surface charge density of the four-prong QTF demonstrated increases of 11.1-fold and 15.9-fold,respectively,compared to that of the standard two-prong QTF.In the simulation of light-induced thermoelastic spectroscopy(LITES)technology,the surface temperature difference of the four-prong QTF was found to be 11.4 times greater than that of the standard QTF.Experimental results indicated that the C_(2)H_(2)-QEPAS system based on this innovative design improved the signal-to-noise-ratio(SNR)by 4.67 times compared with the standard QTF-based system,and the SNR could increase up to 147.72 times when the four-prong QTF was equipped with its optimal acoustic micro-resonator(AmR).When the average time of the system reached 370 s,the system achieved a MDL as low as 21 ppb.The four-prong QTF-based C_(2)H_(2)-LITES system exhibited a SNR improvement by a factor of 4.52,and a MDL of 96 ppb was obtained when the average time of the system reached 100 s.The theoretical and experimental results effectively demonstrated the superiority of the four-prong QTF in the field of laser spectroscopy sensing.展开更多
Mitochondria are vital organelles whose impairment leads to numerous metabolic disorders.Mitochondrial transplantation serves as a promising clinical therapy.However,its widespread application is hindered by the limit...Mitochondria are vital organelles whose impairment leads to numerous metabolic disorders.Mitochondrial transplantation serves as a promising clinical therapy.However,its widespread application is hindered by the limited availability of healthy mitochondria,with the dose required reaching up to 109 mitochondria per injection/patient.This necessitates sustainable and tractable approaches for producing high-quality human mitochondria.In this study,we demonstrated a highly efficient mitochondriaproducing strategy by manipulating mitobiogenesis and tuning organelle balance in human mesenchymal stem cells(MSCs).Utilizing an optimized culture medium(mito-condition)developed from our established formula,we achieved an 854-fold increase in mitochondria production compared to normal MSC culture within 15 days.These mitochondria were not only significantly expanded but also exhibited superior function both before and after isolation,with ATP production levels reaching 5.71 times that of normal mitochondria.Mechanistically,we revealed activation of the AMPK pathway and the establishment of a novel cellular state ideal for mitochondrial fabrication,characterized by enhanced proliferation and mitobiogenesis while suppressing other energy-consuming activities.Furthermore,the in vivo function of these mitochondria was validated in the mitotherapy in a mouse osteoarthritis model,resulting in significant cartilage regeneration over a 12-week period.Overall,this study presented a new strategy for the off-the-shelf fabrication of human mitochondria and provided insights into the molecular mechanisms governing organelle synthesis.展开更多
Fire can cause significant damage to the environment,economy,and human lives.If fire can be detected early,the damage can be minimized.Advances in technology,particularly in computer vision powered by deep learning,ha...Fire can cause significant damage to the environment,economy,and human lives.If fire can be detected early,the damage can be minimized.Advances in technology,particularly in computer vision powered by deep learning,have enabled automated fire detection in images and videos.Several deep learning models have been developed for object detection,including applications in fire and smoke detection.This study focuses on optimizing the training hyperparameters of YOLOv8 andYOLOv10models usingBayesianTuning(BT).Experimental results on the large-scale D-Fire dataset demonstrate that this approach enhances detection performance.Specifically,the proposed approach improves the mean average precision at an Intersection over Union(IoU)threshold of 0.5(mAP50)of the YOLOv8s,YOLOv10s,YOLOv8l,and YOLOv10lmodels by 0.26,0.21,0.84,and 0.63,respectively,compared tomodels trainedwith the default hyperparameters.The performance gains are more pronounced in larger models,YOLOv8l and YOLOv10l,than in their smaller counterparts,YOLOv8s and YOLOv10s.Furthermore,YOLOv8 models consistently outperform YOLOv10,with mAP50 improvements of 0.26 for YOLOv8s over YOLOv10s and 0.65 for YOLOv8l over YOLOv10l when trained with BT.These results establish YOLOv8 as the preferred model for fire detection applications where detection performance is prioritized.展开更多
Lanthanide-sensitized upconverting nanoparticles(UCNPs)are widely studied because of their unusual optical characteristics,such as large antenna-generated anti-Stokes shifts,high photostability,and narrow emission ban...Lanthanide-sensitized upconverting nanoparticles(UCNPs)are widely studied because of their unusual optical characteristics,such as large antenna-generated anti-Stokes shifts,high photostability,and narrow emission bandwidths,which can be harnessed for a variety of applications including bioimaging,sensing,information security and high-level anticounterfeiting.The diverse requirements of these applications typically require precise control over upconversion luminescence(UCL).Recently,the concept of energy migration upconversion has emerged as an effective approach to modulate UCL for various lanthanide ions.Moreover,it provides valuable insights into the fundamental comprehension of energy transfer mechanisms on the nanoscale,thereby contributing to the design of efficient lanthanide-sensitized UCNPs and their practical applications.Here we present a comprehensive overview of the latest developments in energy migration upconversion in lanthanide-sensitized nanoparticles for photon upconversion tuning,encompassing design strategies,mechanistic investigations and applications.Additionally,some future prospects in the field of energy migration upconversion are also discussed.展开更多
P2-type layered oxide Na_(2/3)Ni_(1/3)Mn_(2/3)O_(2)(NM)is a promising cathode material for sodium-ion batteries(SIBs).However,the severe irreversible phase transition,sluggish Na+diffusion kinetics,and interfacial sid...P2-type layered oxide Na_(2/3)Ni_(1/3)Mn_(2/3)O_(2)(NM)is a promising cathode material for sodium-ion batteries(SIBs).However,the severe irreversible phase transition,sluggish Na+diffusion kinetics,and interfacial side reactions at high-voltage result in grievous capacity degradation and inferior electrochemical performance.Herein,a dual-function strategy of entropy tuning and artificial cathode electrolyte interface(CEI)layer construction is reported to generate a novel P2-type medium-entropy Na_(0.75)Li_(0.1)Mg_(0.05)Ni_(0.18)Mn_(0.66)Ta_(0.01)O_(2)with NaTaO_(3)surface modification(LMNMT)to address the aforementioned issues.In situ X-ray diffraction reveals that LMNMT exhibits a near zero-strain phase transition with a volume change of only 1.4%,which is significantly lower than that of NM(20.9%),indicating that entropy tuning effectively suppresses irreversible phase transitions and enhances ion diffusion.Kinetic analysis and post-cycling interfacial characterization further confirm that the artificial CEI layer promotes the formation of a stable,thin NaF-rich CEI and reduces interfacial side reactions,thereby further enhancing ion transport kinetics and surface/interface stability.Consequently,the LMNMT electrode exhibits outstanding rate capability(46 mA h g^(−1)at 20 C)and cycling stability(89.5%capacity retention after 200 cycles at 2 C)within the voltage range of 2–4.35 V.The LMNMT also exhibits superior all-climate performance and air stability.This study provides a novel path for the design of high-voltage cathode materials for SIBs.展开更多
Hydrogenation catalysts frequently impose a compromise between activity and selectivity,where maximizing one property inevitably diminishes the other.Researchers from the Dalian Institute of Chemical Physics(DICP)of t...Hydrogenation catalysts frequently impose a compromise between activity and selectivity,where maximizing one property inevitably diminishes the other.Researchers from the Dalian Institute of Chemical Physics(DICP)of the Chinese Academy of Sciences,in collaboration with scholars from University of Science and Technology of China and the Karlsruhe Institute of Technology in Germany,cracked this dilemma by engineering bimetallic catalysts with atomic precision-a breakthrough that boosts hydrogenation efficiency by 35-fold while maintaining pinpoint accuracy,resolving the stubborn activity-selectivity paradox.展开更多
Separation of ternary C_(4) olefins(n-butene,iso-butene and 1,3-butadiene)is very challenging but crucial in the petrol-chemical industry due to their similar molecular sizes and properties.Herein,to optimize the sepa...Separation of ternary C_(4) olefins(n-butene,iso-butene and 1,3-butadiene)is very challenging but crucial in the petrol-chemical industry due to their similar molecular sizes and properties.Herein,to optimize the separation efficiency for separation of C_(4) olefins,a new Hofmann-type MOF,[Ni(piz)Ni(CN)_(4)](piz=piperazine)-isostructural to the typical one[Ni(pyz)Ni(CN)_(4)](pyz=pyrazine),has been synthesized by a facile method from aqueous solution.The pore size reduction of[Ni(piz)Ni(CN)_(4)](3.62A,in contrast to 3.85A in[Ni(pyz)Ni(CN)_(4)])results in negligible iso-butene(i-C_(4)H_(8))uptake(from 2.92 to 0.04 mmol g^(-1))whereas retaining significant uptake for 1,3-butadiene(1,3-C_(4)H_(6),1.96 mmol g^(-1))and n-butene(n-C_(4)H_(8),1.47 mmol g^(-1)),showing much higher uptake ratios of 1,3-C_(4)H_(6)/i-C_(4)H_(8)(47)and n-C_(4)H_(8)/i-C_(4)H_(8)(35)that outperform most of the benchmark porous materials for separating C_(4) olefins.Breakthrough experiments demonstrate successful separation of high-purity(99.9999%)i-C_(4)H_(8) and 1,3-C_(4)H_(6) from equimolar 1,3-C_(4)H_(6)/i-C_(4)H_(8),n-C_(4)H_(8)/i-C_(4)H_(8) and 1,3-C_(4)H_(6)/n-C_(4)H_(8)/i-C_(4)H_(8) mixtures.展开更多
Revealing the factors that affect the vibrational frequency of Stark probe at interface is a pre-requirement for evaluating the absolute interfacial electric field.Here using surface-enhanced infrared absorption(SEIRA...Revealing the factors that affect the vibrational frequency of Stark probe at interface is a pre-requirement for evaluating the absolute interfacial electric field.Here using surface-enhanced infrared absorption(SEIRA)spectroscopy,attenuated total reflection(ATR)spectroscopy and molecular dynamics(MD),we reveal the assembled C≡N at gold nanofilm exhibits a reduced Stark tuning rate(STR)referring to the vibrational frequency shift in response to electric field comparing with the bulk which was regulated by the electron transfer between S and Au.These findings lead to a deeper understanding of the vibrational Stark effect at the interface and provide guidance for improving the interface electric field theory.展开更多
Grooved tuning forks with hierarchical structures have become some of the most widely used piezoelectric quartz microelectromechanical system devices;however,fabricating these devices requires multi-step processes due...Grooved tuning forks with hierarchical structures have become some of the most widely used piezoelectric quartz microelectromechanical system devices;however,fabricating these devices requires multi-step processes due to the complexity of etching of quartz,particularly in specific orientations of the crystal lattice.This paper proposes a one-step fabrication strategy that can form a complete hierarchical structure with only a single etching process using novel lithography patterns.The core principle of this strategy is based on the effect of the size of the groove patterns on quartz etching,whereby trenches of varying depths can be created in a fixed etching time by adjusting the width of the hard mask.Specifically,the device outline and grooved structure can be completed using a seamlessly designed etching pattern and optimized time.Furthermore,the etching structure itself influences the etching results.It was found that dividing a wide trench by including a wall to separate it into two narrow trenches significantly reduces the etching rate,allowing for predictable tuning of the etching rate for wider grooves.This effectively increases the usability and flexibility of the one-step strategy.This was applied to the manufacture of an ultra-small quartz grooved tuning fork resonator with a frequency of 32.768 kHz in a single step,increasing production efficiency by almost 45%and reducing costs by almost 30%compared to current methods.This has great potential for improving the productivity of grooved tuning fork devices.It can also be extended to the fabrication of other quartz crystal devices requiring hierarchical structures.展开更多
Optically detected magnetic resonance(ODMR)has emerged as a powerful technique for quantum sensing,enabling high-sensitivity detection of physical quantities even at room temperature.Solid-state defects,such as nitrog...Optically detected magnetic resonance(ODMR)has emerged as a powerful technique for quantum sensing,enabling high-sensitivity detection of physical quantities even at room temperature.Solid-state defects,such as nitrogen-vacancy(NV)centers in diamond,have demonstrated remarkable capabilities in this domain[1–4].However,these systems are limited by their rigid lattice structures and lack tunability.展开更多
We present a compact optical delay line(ODL)with wide-range continuous tunability on thin-film lithium niobate platform.The proposed device integrates an unbalanced Mach-Zehnder interferometer(MZI)architecture with du...We present a compact optical delay line(ODL)with wide-range continuous tunability on thin-film lithium niobate platform.The proposed device integrates an unbalanced Mach-Zehnder interferometer(MZI)architecture with dual tunable couplers,where each coupler comprises two 2×2 multimode interferometers and a MZI phase-tuning section.Experimental results demonstrate continuous delay tuning from 0 to 293 ps through synchronized control of coupling coefficients,corresponding to a 4 cm path difference between interferometer arms.The measured delay range exhibits excellent agreement with theoretical predictions derived from ODL waveguide parameters.This result addresses critical challenges in integrated photonic systems that require precise temporal control,particularly for applications in optical communications and quantum information processing,where a wide tuning range is paramount.展开更多
In this paper,a novel self-designed inverted-triangular lithium niobate tuning fork(LiNTF)was used to construct gas sensing system for the first time.The optimal ratio of the upper and lower boundaries of the inverted...In this paper,a novel self-designed inverted-triangular lithium niobate tuning fork(LiNTF)was used to construct gas sensing system for the first time.The optimal ratio of the upper and lower boundaries of the inverted-triangular LiNTF is found by scanning through finite element analysis(FEA).The surface charge density and stress value of the inverted-triangular LiNTF are both higher than those of the standard quartz tuning fork(QTF).In the lithium niobate-enhanced photoacoustic spectroscopy(LiNPAS)sensing system,the 2f peak and signal-to-noise ratio(SNR)of the inverted-triangular LiNTF are 7.41 times and 5.89 times those of the standard QTF,respectively.After forming acoustic standing wave field with the acoustic micro-resonator(AmR),the LiNPAS system achieves an SNR 56.16 times higher than without the AmR.Based on Allan variance analysis,the system achieves a minimum detection limit(MDL)of 7.25 ppb with an averaging time of 800 seconds.In the light-induced thermoelastic spectroscopy(LITES)sensing system,the 2f peak and SNR of the inverted-triangular LiNTF are 7.82 times and 6.03 times those of the standard QTF,respectively.When the averaging time reaches 100 s,the MDL of the system is found to be 25.78 ppb.展开更多
In order to study the effect of weak noise on the sound signal extraction of mouse (Mus musculus Km) inferior collicular (IC) neurons from environments,we examined the changes in frequency tuning curves (FTCs) of 32 n...In order to study the effect of weak noise on the sound signal extraction of mouse (Mus musculus Km) inferior collicular (IC) neurons from environments,we examined the changes in frequency tuning curves (FTCs) of 32 neurons induced by a weak noise relative to 5 dB below minimum threshold of tone (reMT-5 dB) under free field stimulation conditions.The results were as follows:① There were three types of variations in FTCs,sharpened (34.4%),broadened (18.8%),and unaffected (46.9%),nevertheless,only the alteration of sharpened FTCs was statistically different.② Sharpness of frequency tuning induced by a reMT-5 dB noise was very strong.Q 10 and Q 30 of FTCs were increased by (34.42±17.04)% (P=0.026,n=11) and (46.34±22.88)% (P=0.009,n=7).③ The changes of inverse-slopes (ISs,kHz/dB) between high (IS high) and low (IS low) limbs of FTCs were dissymmetry.The IS high of FTCs decreased markedly (P=0.046,n=7),however,there was little change (P=0.947,n=7) in IS low.Our data revealed for the first time that the weak noise could sharpen frequency tuning and increase the sensitivity on the high frequency of sound signal in IC neurons of mouse.展开更多
The next generation of synchrotron radiation light sources features extremely low emittance,enabling the generation of synchrotron radiation with significantly higher brilliance,which facilitates the exploration of ma...The next generation of synchrotron radiation light sources features extremely low emittance,enabling the generation of synchrotron radiation with significantly higher brilliance,which facilitates the exploration of matter at smaller scales.However,the extremely low emittance results in stronger sextupole magnet strengths,leading to high natural chromaticity.This necessitates the use of sextupole magnets to correct the natural chromaticity.For the Shanghai Synchrotron Radiation Facility Upgrade(SSRF-U),a lattice was designed for the storage ring that can achieve an ultra-low natural emittance of 72.2 pm·rad at the beam energy of 3.5 GeV.However,the significant detuning effects,driven by high second-order resonant driving terms due to strong sextupoles,will degrade the performance of the facility.To resolve this issue,installation of octupoles in the SSRF-U storage ring has been planned.This paper presents the study results on configuration selection and optimization method for the octupoles.An optimal solution for the SSRF-U storage ring was obtained to effectively mitigate the amplitude-dependent tune shift and the second-order chromaticity,consequently leading to an increased dynamic aperture(DA),momentum acceptance(MA),and reduced sensitivity to magnetic field errors.展开更多
The micro quartz crystal tuning fork gyroscope is a new type of vibratory gyroscope. The gyroscope should be analyzed and simulated early in the design stage in order to offer reliable basis for design and to shorten ...The micro quartz crystal tuning fork gyroscope is a new type of vibratory gyroscope. The gyroscope should be analyzed and simulated early in the design stage in order to offer reliable basis for design and to shorten the period of development. Thus the vibratory characteristics of the gyroscope is simulated with the finite element method of coupled field. The optimum exciting frequency and the factors which influence the gyroscope sensitivity are determined. The method for adjusting the frequency deviation between driving and detecting modes is also proposed.展开更多
基金funding support from the National Natural Science Foundation of China(Grant No.12525405)funding support from the National Natural Science Foundation of China(Grant No.12393831)the CAS Project for Young Scientists in Basic Research(Grant No.YSBR-120)。
文摘Self-trapped excitons(STEs),known for their unique radiative properties,have been harnessed in diverse photonic devices;however,their comprehensive understanding and manipulation remain elusive.In this study,we present novel experimental and theoretical evidence revealing the hybrid nature and optical tunability of STE state in Cs_(2)Ag_(0.4)Na_(0.6)InCl_(6).The detection of the Fano resonance in laser energy-dependent Raman and photoluminescence spectra indicates the emergence of an exciton-phonon hybrid state,arising from robust quantum interference between the discrete phonon and continuum exciton states.Moreover,we demonstrate continuous tuning of this hybrid state with the energy and intensity of the laser field.These findings lay the foundation for a comprehensive understanding of the nature of STE and their potential for state control.
基金supported by the Aeronautical Science Foundation of China(Nos.20220058052002,20240007052001)。
文摘In this paper,a practical method named linear active disturbance rejection control(LADRC)with adaptive tuning is proposed for attitude control of small-scale unmanned helicopter.The proposed method accounts for both external disturbances and internal dynamic uncertainties,as well as parameter deviations arising from parameter uncertainty,while maintaining a relatively small number of adjustable parameters.Furthermore,it addresses the limitation that conventional active disturbance rejection control methods cannot be rigorously analyzed for stability.The total disturbance of unmanned helicopter is estimated and compensated by designed LADRC.The introduction of adaptive control realizes online parameter tuning,which eliminates parameter deviation and further improves control precision.Moreover,it also provides a novel idea to prove the stability of controller,so that it can be analyzed by Lyapunov function.Finally,the anti-disturbance performance and effectiveness of proposed method are verified by numerical simulation.
基金financial supports from the National Natural Science Foundation of China(Grant No.62335006,62275065,624B2050,62022032,and 62405078)Open Subject of Hebei Key Laboratory of Advanced Laser Technology and Equipment(HBKL-ALTE2025001)+2 种基金Heilongjiang Postdoctoral Fund(Grant No.LBH-Z23144 and LBH-Z24155)Natural Science Foundation of Heilongjiang Province(Grant No.LH2024F031)China Postdoctoral Science Foundation(Grant No.2024M764172).
文摘In this paper,a fast step heterodyne light-induced thermoelastic spectroscopy(SH-LITES)sensor using a high-frequency quartz tuning fork(QTF)with resonant frequency of~100 kHz is reported for the first time.The theoretical principle of heterodyne LITES(H-LITES)signal generation is analyzed firstly,and an acetylene(C_(2)H_(2))H-LITES sensor is established to verify its performance.Experimental comparisons between the high-frequency QTF and a standard commercial QTF with resonant frequency of~32.768 kHz reveal that the high-frequency QTF exhibits a tenfold faster response time.Specifically,the H-LITES sensor with this QTF achieves a 33 ms measurement cycle,90%shorter than commercial counterparts.Furthermore,The SH-LITES technique is proposed to further shorten the scanning time to 15 ms,which achieves the shortest LITES measurement time known to date.To demonstrate its advantages in dynamic gas detection,an H_(2)O-LITES system integrating both QTF types is constructed for real-time monitoring of H_(2)O concentration during different respiration patterns.Comparative measurements show that the SH-LITES more accurately captures dynamic H_(2)O concentration fluctuations during respiration,outperforming the commercial QTF-based H-LITES sensor in rapid response scenarios.
基金supported by the Natural Science Research Project of Colleges and Universities in Anhui Province (No.KJ2021A0479)the Science Research Program of Anhui University of Finance and Economics (No.ACKYC22082)。
文摘We present a gain adaptive tuning method for fiber Raman amplifier(FRA) using two-stage neural networks(NNs) and double weights updates. After training the connection weights of two-stage NNs separately in training phase, the connection weights of the unified NN are updated again in verification phase according to error between the predicted and target gains to eliminate the inherent error of the NNs. The simulation results show that the mean of root mean square error(RMSE) and maximum error of gains are 0.131 d B and 0.281 d B, respectively. It shows that the method can realize adaptive adjustment function of FRA gain with high accuracy.
基金supports from the National Natural Science Foundation of China(Grant Nos.62335006,62022032,62275065,and 62405078)Key Laboratory of Opto-Electronic Information Acquisition and Manipulation(Anhui University),Ministry of Education(Grant No.OEIAM202202)+2 种基金Fundamental Research Funds for the Central Universities(Grant No.HIT.OCEF.2023011)China Postdoctoral Science Foundation(Grant No.2024M764172)Heilongjiang Postdoctoral Fund(Grant No.LBH-Z23144).
文摘In this paper,a novel four-prong quartz tuning fork(QTF)was designed with enlarged deformation area,large prong gap,and low resonant frequency to improve its performance in laser spectroscopy sensing.A theoretical simulation model was established to optimize the design of the QTF structure.In the simulation of quartz-enhanced photoacoustic spectroscopy(QEPAS)technology,the maximum stress and the surface charge density of the four-prong QTF demonstrated increases of 11.1-fold and 15.9-fold,respectively,compared to that of the standard two-prong QTF.In the simulation of light-induced thermoelastic spectroscopy(LITES)technology,the surface temperature difference of the four-prong QTF was found to be 11.4 times greater than that of the standard QTF.Experimental results indicated that the C_(2)H_(2)-QEPAS system based on this innovative design improved the signal-to-noise-ratio(SNR)by 4.67 times compared with the standard QTF-based system,and the SNR could increase up to 147.72 times when the four-prong QTF was equipped with its optimal acoustic micro-resonator(AmR).When the average time of the system reached 370 s,the system achieved a MDL as low as 21 ppb.The four-prong QTF-based C_(2)H_(2)-LITES system exhibited a SNR improvement by a factor of 4.52,and a MDL of 96 ppb was obtained when the average time of the system reached 100 s.The theoretical and experimental results effectively demonstrated the superiority of the four-prong QTF in the field of laser spectroscopy sensing.
基金supported by the National Key Research and Development Program of China(2022YFA1106800)the National Natural Science Foundation of China(T2121004,82394441,92268203).
文摘Mitochondria are vital organelles whose impairment leads to numerous metabolic disorders.Mitochondrial transplantation serves as a promising clinical therapy.However,its widespread application is hindered by the limited availability of healthy mitochondria,with the dose required reaching up to 109 mitochondria per injection/patient.This necessitates sustainable and tractable approaches for producing high-quality human mitochondria.In this study,we demonstrated a highly efficient mitochondriaproducing strategy by manipulating mitobiogenesis and tuning organelle balance in human mesenchymal stem cells(MSCs).Utilizing an optimized culture medium(mito-condition)developed from our established formula,we achieved an 854-fold increase in mitochondria production compared to normal MSC culture within 15 days.These mitochondria were not only significantly expanded but also exhibited superior function both before and after isolation,with ATP production levels reaching 5.71 times that of normal mitochondria.Mechanistically,we revealed activation of the AMPK pathway and the establishment of a novel cellular state ideal for mitochondrial fabrication,characterized by enhanced proliferation and mitobiogenesis while suppressing other energy-consuming activities.Furthermore,the in vivo function of these mitochondria was validated in the mitotherapy in a mouse osteoarthritis model,resulting in significant cartilage regeneration over a 12-week period.Overall,this study presented a new strategy for the off-the-shelf fabrication of human mitochondria and provided insights into the molecular mechanisms governing organelle synthesis.
基金supported by the MSIT(Ministry of Science and ICT),Republic of Korea,under the ITRC(Information Technology Research Center)Support Program(IITP-2024-RS-2022-00156354)supervised by the IITP(Institute for Information&Communications Technology Planning&Evaluation)supported by the Technology Development Program(RS-2023-00264489)funded by the Ministry of SMEs and Startups(MSS,Republic of Korea).
文摘Fire can cause significant damage to the environment,economy,and human lives.If fire can be detected early,the damage can be minimized.Advances in technology,particularly in computer vision powered by deep learning,have enabled automated fire detection in images and videos.Several deep learning models have been developed for object detection,including applications in fire and smoke detection.This study focuses on optimizing the training hyperparameters of YOLOv8 andYOLOv10models usingBayesianTuning(BT).Experimental results on the large-scale D-Fire dataset demonstrate that this approach enhances detection performance.Specifically,the proposed approach improves the mean average precision at an Intersection over Union(IoU)threshold of 0.5(mAP50)of the YOLOv8s,YOLOv10s,YOLOv8l,and YOLOv10lmodels by 0.26,0.21,0.84,and 0.63,respectively,compared tomodels trainedwith the default hyperparameters.The performance gains are more pronounced in larger models,YOLOv8l and YOLOv10l,than in their smaller counterparts,YOLOv8s and YOLOv10s.Furthermore,YOLOv8 models consistently outperform YOLOv10,with mAP50 improvements of 0.26 for YOLOv8s over YOLOv10s and 0.65 for YOLOv8l over YOLOv10l when trained with BT.These results establish YOLOv8 as the preferred model for fire detection applications where detection performance is prioritized.
基金supported by Senior Talent Fund of Jiangsu University(No.5501310021)China Postdoctoral Science Foundation(No.2023M741419)+1 种基金the Young Elite Scientist Sponsorship Program by ZJAST(No.G301310002)Research Fund for International Scientists(No.22350710187).
文摘Lanthanide-sensitized upconverting nanoparticles(UCNPs)are widely studied because of their unusual optical characteristics,such as large antenna-generated anti-Stokes shifts,high photostability,and narrow emission bandwidths,which can be harnessed for a variety of applications including bioimaging,sensing,information security and high-level anticounterfeiting.The diverse requirements of these applications typically require precise control over upconversion luminescence(UCL).Recently,the concept of energy migration upconversion has emerged as an effective approach to modulate UCL for various lanthanide ions.Moreover,it provides valuable insights into the fundamental comprehension of energy transfer mechanisms on the nanoscale,thereby contributing to the design of efficient lanthanide-sensitized UCNPs and their practical applications.Here we present a comprehensive overview of the latest developments in energy migration upconversion in lanthanide-sensitized nanoparticles for photon upconversion tuning,encompassing design strategies,mechanistic investigations and applications.Additionally,some future prospects in the field of energy migration upconversion are also discussed.
基金supported by the National Natural Science Foundation of China(52272295,52071137,51977071,51802040,and 21802020)the Science and Technology Innovation Program of Hunan Province(2021RC3066 and 2021RC3067)+2 种基金the Natural Science Foundation of Hunan Province(2020JJ3004 and 2020JJ4192)Graduate Research Innovation Project of Hunan Province(CX20240456 and CX20240405)N.Zhang and X.Xie also acknowledge the financial support of the Fundamental Research Funds for the Central。
文摘P2-type layered oxide Na_(2/3)Ni_(1/3)Mn_(2/3)O_(2)(NM)is a promising cathode material for sodium-ion batteries(SIBs).However,the severe irreversible phase transition,sluggish Na+diffusion kinetics,and interfacial side reactions at high-voltage result in grievous capacity degradation and inferior electrochemical performance.Herein,a dual-function strategy of entropy tuning and artificial cathode electrolyte interface(CEI)layer construction is reported to generate a novel P2-type medium-entropy Na_(0.75)Li_(0.1)Mg_(0.05)Ni_(0.18)Mn_(0.66)Ta_(0.01)O_(2)with NaTaO_(3)surface modification(LMNMT)to address the aforementioned issues.In situ X-ray diffraction reveals that LMNMT exhibits a near zero-strain phase transition with a volume change of only 1.4%,which is significantly lower than that of NM(20.9%),indicating that entropy tuning effectively suppresses irreversible phase transitions and enhances ion diffusion.Kinetic analysis and post-cycling interfacial characterization further confirm that the artificial CEI layer promotes the formation of a stable,thin NaF-rich CEI and reduces interfacial side reactions,thereby further enhancing ion transport kinetics and surface/interface stability.Consequently,the LMNMT electrode exhibits outstanding rate capability(46 mA h g^(−1)at 20 C)and cycling stability(89.5%capacity retention after 200 cycles at 2 C)within the voltage range of 2–4.35 V.The LMNMT also exhibits superior all-climate performance and air stability.This study provides a novel path for the design of high-voltage cathode materials for SIBs.
文摘Hydrogenation catalysts frequently impose a compromise between activity and selectivity,where maximizing one property inevitably diminishes the other.Researchers from the Dalian Institute of Chemical Physics(DICP)of the Chinese Academy of Sciences,in collaboration with scholars from University of Science and Technology of China and the Karlsruhe Institute of Technology in Germany,cracked this dilemma by engineering bimetallic catalysts with atomic precision-a breakthrough that boosts hydrogenation efficiency by 35-fold while maintaining pinpoint accuracy,resolving the stubborn activity-selectivity paradox.
基金supported by National Natural Science Foundation of China(22090061,22375221)Fundamental Research Program of Shanxi Province(No.202203021223004)+1 种基金Program for Guangdong Introducing Innovative and Entrepreneurial Teams(2017ZT07C069)Hundred Talents Program of Sun Yat-Sen University.
文摘Separation of ternary C_(4) olefins(n-butene,iso-butene and 1,3-butadiene)is very challenging but crucial in the petrol-chemical industry due to their similar molecular sizes and properties.Herein,to optimize the separation efficiency for separation of C_(4) olefins,a new Hofmann-type MOF,[Ni(piz)Ni(CN)_(4)](piz=piperazine)-isostructural to the typical one[Ni(pyz)Ni(CN)_(4)](pyz=pyrazine),has been synthesized by a facile method from aqueous solution.The pore size reduction of[Ni(piz)Ni(CN)_(4)](3.62A,in contrast to 3.85A in[Ni(pyz)Ni(CN)_(4)])results in negligible iso-butene(i-C_(4)H_(8))uptake(from 2.92 to 0.04 mmol g^(-1))whereas retaining significant uptake for 1,3-butadiene(1,3-C_(4)H_(6),1.96 mmol g^(-1))and n-butene(n-C_(4)H_(8),1.47 mmol g^(-1)),showing much higher uptake ratios of 1,3-C_(4)H_(6)/i-C_(4)H_(8)(47)and n-C_(4)H_(8)/i-C_(4)H_(8)(35)that outperform most of the benchmark porous materials for separating C_(4) olefins.Breakthrough experiments demonstrate successful separation of high-purity(99.9999%)i-C_(4)H_(8) and 1,3-C_(4)H_(6) from equimolar 1,3-C_(4)H_(6)/i-C_(4)H_(8),n-C_(4)H_(8)/i-C_(4)H_(8) and 1,3-C_(4)H_(6)/n-C_(4)H_(8)/i-C_(4)H_(8) mixtures.
基金The National Key R&D Program of China(No.2022YFE0113000)the National Science Fund for Distinguished Young Scholars(No.22025406)+1 种基金the National Natural Science Foundation of China(Nos.22074138,12174457)the Youth Innovation Promotion Association of CAS(No.2020233)for financial support。
文摘Revealing the factors that affect the vibrational frequency of Stark probe at interface is a pre-requirement for evaluating the absolute interfacial electric field.Here using surface-enhanced infrared absorption(SEIRA)spectroscopy,attenuated total reflection(ATR)spectroscopy and molecular dynamics(MD),we reveal the assembled C≡N at gold nanofilm exhibits a reduced Stark tuning rate(STR)referring to the vibrational frequency shift in response to electric field comparing with the bulk which was regulated by the electron transfer between S and Au.These findings lead to a deeper understanding of the vibrational Stark effect at the interface and provide guidance for improving the interface electric field theory.
文摘Grooved tuning forks with hierarchical structures have become some of the most widely used piezoelectric quartz microelectromechanical system devices;however,fabricating these devices requires multi-step processes due to the complexity of etching of quartz,particularly in specific orientations of the crystal lattice.This paper proposes a one-step fabrication strategy that can form a complete hierarchical structure with only a single etching process using novel lithography patterns.The core principle of this strategy is based on the effect of the size of the groove patterns on quartz etching,whereby trenches of varying depths can be created in a fixed etching time by adjusting the width of the hard mask.Specifically,the device outline and grooved structure can be completed using a seamlessly designed etching pattern and optimized time.Furthermore,the etching structure itself influences the etching results.It was found that dividing a wide trench by including a wall to separate it into two narrow trenches significantly reduces the etching rate,allowing for predictable tuning of the etching rate for wider grooves.This effectively increases the usability and flexibility of the one-step strategy.This was applied to the manufacture of an ultra-small quartz grooved tuning fork resonator with a frequency of 32.768 kHz in a single step,increasing production efficiency by almost 45%and reducing costs by almost 30%compared to current methods.This has great potential for improving the productivity of grooved tuning fork devices.It can also be extended to the fabrication of other quartz crystal devices requiring hierarchical structures.
文摘Optically detected magnetic resonance(ODMR)has emerged as a powerful technique for quantum sensing,enabling high-sensitivity detection of physical quantities even at room temperature.Solid-state defects,such as nitrogen-vacancy(NV)centers in diamond,have demonstrated remarkable capabilities in this domain[1–4].However,these systems are limited by their rigid lattice structures and lack tunability.
基金supported by the National Natural Science Foundation of China(Grant Nos.12192251,12334014,12404378,92480001,12134001,12174113,12174107,12474325,12404379,and 12474378)the Innovation Program for Quantum Science and Technology(Grant No.2021ZD0301403)+1 种基金Shanghai Municipal Science and Technology Major Project(Grant No.2019SHZDZX01)Fundamental Research Funds for the Central Universities,the Engineering Research Center for Nanophotonics&Advanced Instrument,Ministry of Education,East China Normal University(Grant No.2023nmc005).
文摘We present a compact optical delay line(ODL)with wide-range continuous tunability on thin-film lithium niobate platform.The proposed device integrates an unbalanced Mach-Zehnder interferometer(MZI)architecture with dual tunable couplers,where each coupler comprises two 2×2 multimode interferometers and a MZI phase-tuning section.Experimental results demonstrate continuous delay tuning from 0 to 293 ps through synchronized control of coupling coefficients,corresponding to a 4 cm path difference between interferometer arms.The measured delay range exhibits excellent agreement with theoretical predictions derived from ODL waveguide parameters.This result addresses critical challenges in integrated photonic systems that require precise temporal control,particularly for applications in optical communications and quantum information processing,where a wide tuning range is paramount.
基金supported by the National Natural Science Foundation of China(Grant Nos.62335006,62275065,62022032,62405078,and 62505066)Open Subject of Hebei Key Laboratory of Advanced Laser Technology and Equipment(Grant No.HBKL-ALTE2025001)+2 种基金Heilongjiang Postdoctoral Fund(Grant No.LBH-Z23144 and LBH-Z24155)Natural Science Foundation of Heilongjiang Province(Grant No.LH2024F031)China Postdoctoral Science Foundation(Grant No.2024M764172).
文摘In this paper,a novel self-designed inverted-triangular lithium niobate tuning fork(LiNTF)was used to construct gas sensing system for the first time.The optimal ratio of the upper and lower boundaries of the inverted-triangular LiNTF is found by scanning through finite element analysis(FEA).The surface charge density and stress value of the inverted-triangular LiNTF are both higher than those of the standard quartz tuning fork(QTF).In the lithium niobate-enhanced photoacoustic spectroscopy(LiNPAS)sensing system,the 2f peak and signal-to-noise ratio(SNR)of the inverted-triangular LiNTF are 7.41 times and 5.89 times those of the standard QTF,respectively.After forming acoustic standing wave field with the acoustic micro-resonator(AmR),the LiNPAS system achieves an SNR 56.16 times higher than without the AmR.Based on Allan variance analysis,the system achieves a minimum detection limit(MDL)of 7.25 ppb with an averaging time of 800 seconds.In the light-induced thermoelastic spectroscopy(LITES)sensing system,the 2f peak and SNR of the inverted-triangular LiNTF are 7.82 times and 6.03 times those of the standard QTF,respectively.When the averaging time reaches 100 s,the MDL of the system is found to be 25.78 ppb.
文摘In order to study the effect of weak noise on the sound signal extraction of mouse (Mus musculus Km) inferior collicular (IC) neurons from environments,we examined the changes in frequency tuning curves (FTCs) of 32 neurons induced by a weak noise relative to 5 dB below minimum threshold of tone (reMT-5 dB) under free field stimulation conditions.The results were as follows:① There were three types of variations in FTCs,sharpened (34.4%),broadened (18.8%),and unaffected (46.9%),nevertheless,only the alteration of sharpened FTCs was statistically different.② Sharpness of frequency tuning induced by a reMT-5 dB noise was very strong.Q 10 and Q 30 of FTCs were increased by (34.42±17.04)% (P=0.026,n=11) and (46.34±22.88)% (P=0.009,n=7).③ The changes of inverse-slopes (ISs,kHz/dB) between high (IS high) and low (IS low) limbs of FTCs were dissymmetry.The IS high of FTCs decreased markedly (P=0.046,n=7),however,there was little change (P=0.947,n=7) in IS low.Our data revealed for the first time that the weak noise could sharpen frequency tuning and increase the sensitivity on the high frequency of sound signal in IC neurons of mouse.
文摘The next generation of synchrotron radiation light sources features extremely low emittance,enabling the generation of synchrotron radiation with significantly higher brilliance,which facilitates the exploration of matter at smaller scales.However,the extremely low emittance results in stronger sextupole magnet strengths,leading to high natural chromaticity.This necessitates the use of sextupole magnets to correct the natural chromaticity.For the Shanghai Synchrotron Radiation Facility Upgrade(SSRF-U),a lattice was designed for the storage ring that can achieve an ultra-low natural emittance of 72.2 pm·rad at the beam energy of 3.5 GeV.However,the significant detuning effects,driven by high second-order resonant driving terms due to strong sextupoles,will degrade the performance of the facility.To resolve this issue,installation of octupoles in the SSRF-U storage ring has been planned.This paper presents the study results on configuration selection and optimization method for the octupoles.An optimal solution for the SSRF-U storage ring was obtained to effectively mitigate the amplitude-dependent tune shift and the second-order chromaticity,consequently leading to an increased dynamic aperture(DA),momentum acceptance(MA),and reduced sensitivity to magnetic field errors.
文摘The micro quartz crystal tuning fork gyroscope is a new type of vibratory gyroscope. The gyroscope should be analyzed and simulated early in the design stage in order to offer reliable basis for design and to shorten the period of development. Thus the vibratory characteristics of the gyroscope is simulated with the finite element method of coupled field. The optimum exciting frequency and the factors which influence the gyroscope sensitivity are determined. The method for adjusting the frequency deviation between driving and detecting modes is also proposed.
