We investigate the flow patterns of irregular sand particles under avalanching mode in a rotating drum by using the spatial filtering velocimetry technique.By exploring the variations of velocity distribution of granu...We investigate the flow patterns of irregular sand particles under avalanching mode in a rotating drum by using the spatial filtering velocimetry technique.By exploring the variations of velocity distribution of granular flow,we find a type of avalanching pattern of irregular sand particles which is similar to that of spherical particles flow.Due to the fact that the initial position of avalanche in this pattern locates at the middle of the drum and the avalanche propagates toward the edge area gradually,we named it as mid-to-edge avalanching pattern.Furthermore,we find another avalanching pattern which slumps from the edge and propagates toward the opposite edge of the flow surface,named as edge-to-edge pattern.By analyzing the temporal and spatial characteristics of these two types of avalanching patterns,we discover that these two types of avalanche patterns are caused by that the avalanching particles constantly perturb the axial adjacent particles.Thus,the particles on the flow surface are involved in avalanching sequentially in order of the axial distance from the initial position.展开更多
Photon avalanche (PA) is a nonlinear optical phenomenon characterized by steep up conversion emission growth with excitation power.Since the first demonstration of PA on nanoscale and at room temperature (RT) in 2021 ...Photon avalanche (PA) is a nonlinear optical phenomenon characterized by steep up conversion emission growth with excitation power.Since the first demonstration of PA on nanoscale and at room temperature (RT) in 2021 [1], PA luminescence of lanthanides has received considerable attention in the communities of nano-and bio-photonics [2,3].Hitherto,PA of Tm^(3+),Yb^(3+)-Pr^(3+),and Nd^(3+) has been achieved in several fluoride and bromide nanoparticles (NPs),enabling large nonlinearities (N> 10) for applications in areas such as superresolution imaging [4],optical data storage and processing [5],lithographic microfabrication [6], and optical sensing [7].展开更多
A 32-channel charge-sensitive amplifier(CSA)is designed for fast timing in the delay-line readout of a parallel plate avalanche counter(PPAC)array.It is realized on a PCB with operational amplifiers and other discrete...A 32-channel charge-sensitive amplifier(CSA)is designed for fast timing in the delay-line readout of a parallel plate avalanche counter(PPAC)array.It is realized on a PCB with operational amplifiers and other discrete components.Each channel consists of an integrator,a pole-zero cancellation net,and a linear amplification stage,which can be adapted to accommodate either positive or negative input signals.The RMS equivalent input noise charges are 3.3 fC,the conversion gains are approximately±2 mV∕fC,and the intrinsic time resolution reaches 32 ps.In the prototype PPAC application,the CSA performs as well as the commercial FTA820A amplifier,providing a position resolution as good as 0.17 mm,and exhibiting reliable stability during several hours of continuous data acquisition.展开更多
This study represents a pioneering effort to analyze the impact of avalanches descending into Morskie Oko from Marchwiczny Gully,the most active avalanche path around the lake.It focuses on catastrophic avalanches tha...This study represents a pioneering effort to analyze the impact of avalanches descending into Morskie Oko from Marchwiczny Gully,the most active avalanche path around the lake.It focuses on catastrophic avalanches that descended from the analyzed gully,as reported in the literature from the 1900s until now.However,only the data collected in recent years,our field studies,combined with modern LIDAR data and GIS-based modeling,allowed us to perform a detailed analysis.The GIS-based approach effectively uses spatial data to address snow avalanche modeling challenges.Although the study area lies within Tatra National Park,no official services carry out systematic avalanche monitoring or measurements.The impact of hazardous events,such as snow avalanches,on the most famous Polish mountain lake,Morskie Oko,has been poorly described in the literature and has yet to be discovered.Therefore,to analyze the selected avalanche parameters,we mainly used our ground and additional aerial photographs taken by local mountain services and related field measurements.Our analysis resulted in figurative estimates of the extent and volume of avalanche snow and its weight,both on the surface of the ice sheet and the part of the avalanche that did not reach the lake's shore and remained on the slope of Marchwiczny Gully.For example,the values for the mighty avalanche on February 3,2023,are 23,500 m~3 and 4,700 tons on the ice surface and 20,000 m~3 and 4,000 tons on the slope.It was determined that avalanches that descend onto the studied lake's surface result in its shallowing.This process occurs because of sedimentation of slope material carried by avalanches,especially during the final phase of ice cover melting.When openings appear in the solid ice cover in spring,floating ice can migrate,driven by wind pressure,and deposit avalanche material in various parts of the lake bottom.Thus,avalanches contributed to the gradual disappearance of the lake.展开更多
The dynamic avalanche effect is a critical factor influencing the performance and reliability of the field-stop insulated gate bipolar transistors(FS-IGBT).Unclamped inductive switching(UIS)is the primary method for t...The dynamic avalanche effect is a critical factor influencing the performance and reliability of the field-stop insulated gate bipolar transistors(FS-IGBT).Unclamped inductive switching(UIS)is the primary method for testing the dynamic avalanche capability of FS-IGBTs.Numerous studies have demonstrated that factors such as device structure,avalanche-generating current filaments,and electrical parameters influence the dynamic avalanche effect of the FS-IGBT.However,few studies have focused on enhancing the avalanche reliability of the FS-IGBT by adjusting circuit parameters during operation.In this paper,the dynamic avalanche effect of the FS-IGBT under UIS conditions is comprehensively investigated through a series of comparative experiments with varying circuit parameters,including bus voltage V_(DC),gate voltage V_(G),gate resistance R_(g),load inductance L,and temperature TC.Furthermore,a method to enhance the dynamic avalanche reliability of the FS-IGBT under UIS by optimizing circuit parameters is proposed.In practical applications,reducing gate voltage,increasing load inductance,and lowering temperature can effectively improve the dynamic avalanche capability of the FS-IGBT.展开更多
The precise mathematical method was adopted to simulate the breakdown process of 5 mm rod and plate electrode gap,which was filled with supercritical nitrogen at the condition of 127 K,4 MPa and seed electron density ...The precise mathematical method was adopted to simulate the breakdown process of 5 mm rod and plate electrode gap,which was filled with supercritical nitrogen at the condition of 127 K,4 MPa and seed electron density 1×10^(6) m^(-3) under 29 kV DC voltage.The result shows that the discharge process was completed within 11.8 ns from seed electron triggering,avalanche bulking to streamer extending until gap eventually breakdown.The entire gap breakdown process was divided into three discharge stages,namely,the initial discharge triggered(0-4 ns),avalanche(4-7 ns)and streamer phase(7-11.8 ns).At the same time,the facts were also revealed that the discharge evolution,electric field distribution,and electron density had different values,and also showed different temporal and spatial distribution characteristics along the axis of the discharge gap.Specifically,the discharge characteristics of SCN2 under 1,2,3,4,4.5,and 5 MPa at 127 K were theoretically analyzed respectively,and the microscopic mechanisms of the breakdown process were also detailed.The results indicate that the gas discharge law remained applicable within the 1-3 MPa range.However,the discharge characteristics of supercritical nitrogen at 3.4-5 MPa differed significantly from those at lower pressures,likely attributable to the unique state of matter exhibited by supercritical nitrogen.This study contributes to understanding the discharge mechanism of supercritical nitrogen and offers theoretical guidance for its practical application in the power industry.展开更多
Snow avalanches present a significant threat to infrastructure,affecting buildings,roads,railways,and power lines,and frequently leading to massive economic losses in livelihoods and production.With the increase in re...Snow avalanches present a significant threat to infrastructure,affecting buildings,roads,railways,and power lines,and frequently leading to massive economic losses in livelihoods and production.With the increase in regional temperatures and the occurrence of extreme snowfall events,the frequency and intensity of avalanches have escalated,resulting in more severe incidents and higher casualty rates.As natural archives of environmental changes,tree rings offer valuable proxies for avalanche hazard assessments in regions where direct observation data is scarce,particularly in high-altitude regions.The dendrogeomorphology has been gradually being applied in avalanche hazard evaluation,however,it remains limited in China.To address this gap,this study systematically investigates the principles and methodologies for reconstructing avalanche histories and evaluates their applications in avalanche hazard assessments through a literature review and field observations.It provides a comprehensive overview of recent advancements in key areas,including the impact of avalanches on forest ecosystems,the reconstruction of avalanches,and the analysis of avalanche events(i.e.,the spatiotemporal distribution,the historical recurrence intervals,magnitudes,and triggering conditions of avalanches).Considering the current limitations in avalanche hazard assessments and the urgent need for such research in China,we outline key priorities and future directions,including refining reconstruction methodologies,developing a comprehensive tree-ring-based avalanche database for high-altitude regions,and establishing an advanced hazard assessment framework based on dendrochronological evidence.展开更多
This research presents a numerical simulation methodology for optimizing circular composite overlays’dimensions and pressure characteristics with orthotropic mechanical properties,specifically,for metal conduits with...This research presents a numerical simulation methodology for optimizing circular composite overlays’dimensions and pressure characteristics with orthotropic mechanical properties,specifically,for metal conduits with temperature-dependent elastoplastic behavior.The primary objective of the proposed method is to prevent crack propagation during pressure surges from operational to critical levels.This study examines the“Beineu-Bozoy-Shymkent”steel gas conduit,examining its performance across a temperature range of−40 to+50℃.This work builds on prior research on extended avalanche destruction in steel gas conduits and crack propagation prevention techniques.Theanalysis was conducted using a dynamic finite-element approach with the ANSYS-19.2/ExplicitDynamics software.Simulations of unprotected conduits revealed that increasing gas-dynamic pressure can convert a partial-depth crack into a through-crack,extending longitudinally to approximately seven times its initial length.Notably,at T=+50℃,the developed crack length was 1.2%longer than that at T=−40℃,highlighting the temperature sensitivity of crack progression.The modeling results indicate that crack propagation can be effectively controlled using a circular composite overlay with a thickness between 37.5%and 50%of the crack depth and a length approximately five times that of the initial crack,centered symmetrically over the crack.In addition,preliminary stress analysis indicated that limiting the overlay-induced pressure to 5%of the operational pressure effectively arrested crack growth without generating significant stress concentrations near the overlay boundaries,thereby preventing conduit integrity.展开更多
The impact of cross-sectional topographic variability on the kinetic properties of granular flows has been underexplored,which hinders the understanding of the kinematics of rock avalanches.In this study,the throat co...The impact of cross-sectional topographic variability on the kinetic properties of granular flows has been underexplored,which hinders the understanding of the kinematics of rock avalanches.In this study,the throat contraction index(T)is introduced to quantify variations in throat topography,and 96 numerical simulation experiments with varying T and slope angles(δ)are conducted.The findings indicate that granular flows experience transient obstructions when traversing throat topographies,primarily due to the periodic formation and breaking of the arch structure.Observations suggest that the acceleration of velocity in the tails of granular flows is restrained by the throat region,potentially altering the dynamics of related geohazards.In this study,the impact of throat topography is quantitatively assessed,demonstrating a reduction in peak flowrates of granular materials by 20%-80% and extending the flowduration up to six times.The present study proposes the throat-induced hazard index(Φ)to evaluate the influenceof throat topography on the risk of rockslides and avalanches characterized by granular flows,which may provide insights for the design of mitigation structures in topographic regions.展开更多
In this study,avalanches in the Aerxiangou section of the Duku Expressway in the Tianshan Mountain area of Xinjiang were taken as the research object,and 92 avalanches were accurately identified through onsite researc...In this study,avalanches in the Aerxiangou section of the Duku Expressway in the Tianshan Mountain area of Xinjiang were taken as the research object,and 92 avalanches were accurately identified through onsite research.A high-resolution three-dimensional model was established by collecting images from unmanned aerial vehicles for an in-depth understanding of the avalanche danger of the region,according to the sample set selection of different uses of machine learning support vector machines to establish the S1-RBFKSVM,S1-PKSVM,S2-RBFKSVM,and S2-PKSVM avalanche susceptibility coupling models.On the basis of the avalanche point susceptibility,the impact velocity,impact force,avalanche volume,and throw distance constitute the hazard evaluation system.The study results revealed that slopes in the range of 26.6°–46.9°are more prone to avalanches,and sample set 2 improved the accuracy by approximately 30%compared with sample set 1 trained in the avalanche susceptibility model.Principal component analysis revealed a total of 16 high-risk avalanches,which were distributed mainly on the southern side of the route.This study provides data support for avalanche simulations as well as early warning and prevention and provides theoretical and methodological guidance for the construction and operation of the Duku Expressway.展开更多
Air blasts induced by rock-ice avalanches are common natural phenomena known for their far-field destructive impact.In this study,remote sensing images,eyewitness videos and numerical modelling were comprehensively ap...Air blasts induced by rock-ice avalanches are common natural phenomena known for their far-field destructive impact.In this study,remote sensing images,eyewitness videos and numerical modelling were comprehensively applied to analyze the initiation and propagation of the 2021 Chamoli avalancheinduced air blast.Our findings indicate that air blasts are observed from the avalanche source area to the Rishiganga valley,but nearly disappear in the Dhauliganga valley.The most intense air blast is concentrated on the left side of Ronti Gad valley,with maximum velocity and pressure estimated at over 70 m/s and 20 kPa,respectively.Such high pressure results in widespread tree breakage in the area.Based on the analysis of the Chamoli event,we further discussed the potential contribution of the avalanche flow regime,avalanche dynamics and geomorphology to the destructive potential of air blasts.Rapidly moved sliding mass can impart the air blast a high initial momentum,and this process will be exaggerated when the avalanche impacts valley walls at bends.However,when the rock-ice avalanche transforms into a debris-enriched flash flood,free water within the flowing mass can displace air,inhibiting the generation of air blasts.Our work offers new insights into the generation and propagation of rock-ice avalanche-induced air blasts,underscoring the importance of including this type of hazard during avalanche risk assessment in high-altitude glacial regions.展开更多
Massive granitic rock avalanches are extensively developed in the middle section of the northern Qinling Mountains(NQM),China.The current consensus is that their formation could have been connected with seismic events...Massive granitic rock avalanches are extensively developed in the middle section of the northern Qinling Mountains(NQM),China.The current consensus is that their formation could have been connected with seismic events that occurred in the NQM.However,there is a lack of systematic discussion on the genetic dynamics of these rock avalanches.Hence,taking Earth system scientific research as a starting point,this paper systematically summarizes and discusses development characteristics,formation times and genetic dynamic mechanisms of granitic rock avalanches in the NQM based on geological investigations,high-precision remote sensing interpretations,geomorphological dating,geophysical exploration,and a large-scale shaking table model test.We identified 53 granitic rock avalanches in this area,with a single collapse area ranging from 0.01×10~6 to 1.71×10~6 m^(2).Their development time can be divided into six stages,namely,107000 years BP,11870–11950 years BP,11000 years BP,2300 years BP,1800 years BP,and 1500 years BP,which were closely related to multiple prehistoric or ancient earthquakes.We suggest that long-term coupling of internal and external earth dynamics was responsible for the granitic rock avalanches in the NQM;the internal dynamics were mainly related to subduction,collision and extrusion of different plates under the Qinling terrane,leading to the formation and tectonic uplift of the Qinling orogenic belt;and the external dynamics were closely associated with climate changes resulting in mountain denudation,freeze-thaw cycles and isostatic balance uplift.In this process,the formation and evolution of the Qinling orogenic belt play a geohazard-pregnant role,structural planes,including faults and joints,play a geohazard-controlled role,and earthquakes play a geohazard-induced role,which jointly results in the occurrence of large-scale granitic rock avalanches in the NQM.This research can not only decipher the genetic dynamic mechanism of large hard granitic rock avalanches but also reveal temporal and spatial patterns of the evolution of breeding and the generation of large-scale rock avalanches in the margins of orogenic belts.展开更多
Avalanche photodiode(APD)is a kind of photodetector with important applications in optical communication,light detection and ranging(LIDAR)and other fields.APDs fabricated using the recently developed AlGaAsSb as the ...Avalanche photodiode(APD)is a kind of photodetector with important applications in optical communication,light detection and ranging(LIDAR)and other fields.APDs fabricated using the recently developed AlGaAsSb as the multiplication material exhibit excellent noise performance.In this work,we report a low-noise separate absorption,grading,charge,and multi-plication(SAGCM)InGaAs/AlGaAsSb APD operating at 1550 nm.A double-mesa structure was fabricated to reduce the dark cur-rent.Numerical simulations were conducted to compare two different mesa-structured APDs.By analyzing the electric field distri-bution,it was found that the electric field at the edge of the multiplication region in the double-mesa APD is nearly 100 kV/cm lower than that of the single-mesa structure.Experimental results demonstrate that after device punch-through,the double-mesa APD’s dark current can be reduced by up to four times compared to the single-mesa APD.Quantitative analysis of the dark current components in the AlGaAsSb APD further confirms that the low sidewall electric field in the double-mesa struc-ture effectively suppresses the trap-assisted tunneling.Additionally,noise measurements indicate a k-value of approximately 0.014,which is significantly lower than that of traditional multiplication materials.This work provides preliminary validation for further performance improvements in low noise and low dark current AlGaAsSb APDs.展开更多
Quantum key distribution(QKD)achieves information-theoretic security based on quantum mechanics principles,where single-photon detectors(SPDs)serve as critical components.This study focuses on the sinusoidal gated SPD...Quantum key distribution(QKD)achieves information-theoretic security based on quantum mechanics principles,where single-photon detectors(SPDs)serve as critical components.This study focuses on the sinusoidal gated SPDs widely used in high-speed QKD systems.We investigate the mechanisms underlying the rising-edge jitter in detection signals,identifying contributions from factors such as the temporal width of injected optical pulses,avalanche generation processes,avalanche signal extraction,and pulse discrimination.To address the issue of excessive jitter-induced bit errors,we propose a retiming scheme that utilizes coincidence signals synchronized with the sinusoidal gating signal.This approach effectively suppresses detection signal jitter and reduces the after-pulse probability of the detector.Experimental validation using a high-precision time-to-digital converter(TDC)demonstrates a significant reduction in the rising-edge jitter distribution after applying the suppression scheme.The proposed method features clear principles and straightforward engineering implementation,avoiding direct interference with the detector’s operational processes.The designed high-speed sinusoidal gated InGaAs/InP SPD operates at 1.25 GHz,achieving a remarkable reduction in after-pulse probability from 10.7%(without jitter suppression)to 0.72%,thereby enhancing the overall performance of QKD systems.展开更多
Rapid climate warming is leading to a notable increase in glacier recession and the formation of glacial lakes,which are becoming increasingly characteristic of high mountain regions globally.These severe cryospheric ...Rapid climate warming is leading to a notable increase in glacier recession and the formation of glacial lakes,which are becoming increasingly characteristic of high mountain regions globally.These severe cryospheric changes critically affect regional water supply,increase geohazards,and threaten lives and livelihoods.This study records regional glaciers and glacial lake dynamics for the period 1990 to 2024,considers the implications of these changes for glacial lake outburst floods(GLOFs)and assesses the potential future flood hazard.Several remotely sensed and reanalysis datasets from 1990 to 2024 are employed to investigate changes in glacier and lake areas.The results highlight a significant reduction in the Manaslu(-0.72±0.20 km^(2)/a)and adjoining glaciers,which led to an increase in the Birendra glacial lake(0.23±0.04 km^(2)/a).Additionally,surface elevation and ice movement data reveal significant thinning of glaciers in the region,averaging-1.52±0.26 m/a,often associated with avalanches near the glacier terminus and triggering GLOFs.Using an HEC-RAS(Hydrologic Engineering Center’s River Analysis System)model,a total extension of 19.3 km of flow channels was revealed,coupled with potential increases in depth,discharge,and velocity,potentially causing massive damage downstream.Regional hazard intensity assessment indicates that five bridges,31 houses,and 1.2 km^(2)of agricultural land may be flooded,with the more populated areas near Samagaun and Banjam being the most affected.Regional climate condition,including significant rising air temperature(0.02℃/a,p<0.05)and declining precipitation(-0.24 mm/a,p<0.05),during recent decades play a crucial role in glacier dynamics and exhibit a significant spatial relation with increased temperature(R^(2)=0.62,α<0.05).Understanding regional cryospheric dynamics and associated risks is therefore essential in designing adaptive mitigation strategies.展开更多
The prompt fission neutron spectrum(PFNS)is a key nuclear data quantity that is of particular interest and plays a crucial role in understanding and modeling fission processes.An array comprising 48 liquid scintillati...The prompt fission neutron spectrum(PFNS)is a key nuclear data quantity that is of particular interest and plays a crucial role in understanding and modeling fission processes.An array comprising 48 liquid scintillation detectors and a parallelplate avalanche counter(PPAC)was developed at the China Institute of Atomic Energy(CIAE)to measure the PFNS of actinide nuclei.Efficiency and energy calibrations were performed for all the liquid scintillators,and their efficiencies were consistently found to be better than 5%.The time resolutions of the PPAC and liquid scintillators were measured to be 1.08 ns and 1.16 ns using~(252)Cf and~(207)Bi sources,respectively.The pulse shape discrimination of the liquid scintillator was utilized to identify neutron andγsignals on an event-by-event basis,and the figure of merit was deduced as 1.12 at a 200 ke Vee threshold.The contribution to the PFNS from multiple scattered neutrons was evaluated via Geant4 simulations,and those originating from the environment were found to be comparable to the crosstalk between the detectors.The neutron efficiency of the entire detection array was calibrated using a~(252)Cf spontaneous fission source and was demonstrated to be consistent with the Geant4 simulation results,which verified the reliability of the detection array.展开更多
A near-infrared(NIR) enhanced silicon single-photon avalanche diode(SPAD) detector is proposed using 0.18 μm bipolar-CMOS-DMOS technology. It is based on a deep multiplication region, formed by a junction between the...A near-infrared(NIR) enhanced silicon single-photon avalanche diode(SPAD) detector is proposed using 0.18 μm bipolar-CMOS-DMOS technology. It is based on a deep multiplication region, formed by a junction between the highvoltage P-well(HVPW) and high-voltage buried N+ layer, to enhance the NIR photon detection probability(PDP). Thanks to the lightly doped P-type epitaxial layer, the electric field in the guard ring is reduced and premature breakdown is prevented. In particular, an extra P-type implantation layer(PIL) is added to the HVPW to reduce the breakdown voltage and enhance the device's sensitivity. Further research on the impact of different PIL sizes on the device performance is carried out. It is experimentally shown that at an excess bias voltage of 5 V, the optimized SPAD achieves a dark count rate of 0.64 cps/μm^(2), peak PDP of 54.8% at 555 nm and PDP of 10.53% at 905 nm. The full width at half-maximum of the timing jitter is 285 ps, and the afterpulsing probability is lower than 1.17%. This novel device provides a practical, low-cost solution for high-performance NIR time-of-flight detectors and 3D imaging sensors.展开更多
Disordered ferromagnets with a domain structure that exhibit a hysteresis loop when driven by the external magnetic field are essential materials for modern technological applications.Therefore,the understanding and p...Disordered ferromagnets with a domain structure that exhibit a hysteresis loop when driven by the external magnetic field are essential materials for modern technological applications.Therefore,the understanding and potential for controlling the hysteresis phenomenon in thesematerials,especially concerning the disorder-induced critical behavior on the hysteresis loop,have attracted significant experimental,theoretical,and numerical research efforts.We review the challenges of the numerical modeling of physical phenomena behind the hysteresis loop critical behavior in disordered ferromagnetic systems related to the non-equilibriumstochastic dynamics of domain walls driven by external fields.Specifically,using the extended Random Field Ising Model,we present different simulation approaches and advanced numerical techniques that adequately describe the hysteresis loop shapes and the collective nature of the magnetization fluctuations associated with the criticality of the hysteresis loop for different sample shapes and varied parameters of disorder and rate of change of the external field,as well as the influence of thermal fluctuations and demagnetizing fields.The studied examples demonstrate how these numerical approaches reveal newphysical insights,providing quantitativemeasures of pertinent variables extracted from the systems’simulated or experimentally measured Barkhausen noise signals.The described computational techniques using inherent scale-invariance can be applied to the analysis of various complex systems,both quantum and classical,exhibiting non-equilibrium dynamical critical point or self-organized criticality.展开更多
Based on an avalanche photodiode（ APD） detecting array working in Geiger mode（ GM-APD）, a high-performance infrared sensor readout integrated circuit（ ROIC） used for infrared 3D（ three-dimensional） imaging is ...Based on an avalanche photodiode（ APD） detecting array working in Geiger mode（ GM-APD）, a high-performance infrared sensor readout integrated circuit（ ROIC） used for infrared 3D（ three-dimensional） imaging is proposed. The system mainly consists of three functional modules, including active quenching circuit（ AQC）, time-to-digital converter（ TDC） circuit and other timing controller circuit. Each AQC and TDC circuit together constitutes the pixel circuit. Under the cooperation with other modules, the current signal generated by the GM-APD sensor is detected by the AQC, and the photon time-of-flight（ TOF） is measured and converted to a digital signal output to achieve a better noise suppression and a higher detection sensitivity by the TDC. The ROIC circuit is fabricated by the CSMC 0. 5 μm standard CMOS technology. The array size is 8 × 8, and the center distance of two adjacent cells is 100μm. The measurement results of the chip showthat the performance of the circuit is good, and the chip can achieve 1 ns time resolution with a 250 MHz reference clock, and the circuit can be used in the array structure of the infrared detection system or focal plane array（ FPA）.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11572201,91634202,and 11902190).
文摘We investigate the flow patterns of irregular sand particles under avalanching mode in a rotating drum by using the spatial filtering velocimetry technique.By exploring the variations of velocity distribution of granular flow,we find a type of avalanching pattern of irregular sand particles which is similar to that of spherical particles flow.Due to the fact that the initial position of avalanche in this pattern locates at the middle of the drum and the avalanche propagates toward the edge area gradually,we named it as mid-to-edge avalanching pattern.Furthermore,we find another avalanching pattern which slumps from the edge and propagates toward the opposite edge of the flow surface,named as edge-to-edge pattern.By analyzing the temporal and spatial characteristics of these two types of avalanching patterns,we discover that these two types of avalanche patterns are caused by that the avalanching particles constantly perturb the axial adjacent particles.Thus,the particles on the flow surface are involved in avalanching sequentially in order of the axial distance from the initial position.
文摘Photon avalanche (PA) is a nonlinear optical phenomenon characterized by steep up conversion emission growth with excitation power.Since the first demonstration of PA on nanoscale and at room temperature (RT) in 2021 [1], PA luminescence of lanthanides has received considerable attention in the communities of nano-and bio-photonics [2,3].Hitherto,PA of Tm^(3+),Yb^(3+)-Pr^(3+),and Nd^(3+) has been achieved in several fluoride and bromide nanoparticles (NPs),enabling large nonlinearities (N> 10) for applications in areas such as superresolution imaging [4],optical data storage and processing [5],lithographic microfabrication [6], and optical sensing [7].
基金supported by the National Natural Science Foundation of China(Nos.U2167202,12225504,12005276)the Natural Science Foundation of Shandong Province(No.ZR2024QA172)the Fundamental Research Funds of Shandong University.
文摘A 32-channel charge-sensitive amplifier(CSA)is designed for fast timing in the delay-line readout of a parallel plate avalanche counter(PPAC)array.It is realized on a PCB with operational amplifiers and other discrete components.Each channel consists of an integrator,a pole-zero cancellation net,and a linear amplification stage,which can be adapted to accommodate either positive or negative input signals.The RMS equivalent input noise charges are 3.3 fC,the conversion gains are approximately±2 mV∕fC,and the intrinsic time resolution reaches 32 ps.In the prototype PPAC application,the CSA performs as well as the commercial FTA820A amplifier,providing a position resolution as good as 0.17 mm,and exhibiting reliable stability during several hours of continuous data acquisition.
文摘This study represents a pioneering effort to analyze the impact of avalanches descending into Morskie Oko from Marchwiczny Gully,the most active avalanche path around the lake.It focuses on catastrophic avalanches that descended from the analyzed gully,as reported in the literature from the 1900s until now.However,only the data collected in recent years,our field studies,combined with modern LIDAR data and GIS-based modeling,allowed us to perform a detailed analysis.The GIS-based approach effectively uses spatial data to address snow avalanche modeling challenges.Although the study area lies within Tatra National Park,no official services carry out systematic avalanche monitoring or measurements.The impact of hazardous events,such as snow avalanches,on the most famous Polish mountain lake,Morskie Oko,has been poorly described in the literature and has yet to be discovered.Therefore,to analyze the selected avalanche parameters,we mainly used our ground and additional aerial photographs taken by local mountain services and related field measurements.Our analysis resulted in figurative estimates of the extent and volume of avalanche snow and its weight,both on the surface of the ice sheet and the part of the avalanche that did not reach the lake's shore and remained on the slope of Marchwiczny Gully.For example,the values for the mighty avalanche on February 3,2023,are 23,500 m~3 and 4,700 tons on the ice surface and 20,000 m~3 and 4,000 tons on the slope.It was determined that avalanches that descend onto the studied lake's surface result in its shallowing.This process occurs because of sedimentation of slope material carried by avalanches,especially during the final phase of ice cover melting.When openings appear in the solid ice cover in spring,floating ice can migrate,driven by wind pressure,and deposit avalanche material in various parts of the lake bottom.Thus,avalanches contributed to the gradual disappearance of the lake.
基金supported in part by the National Natural Science Foundation of China under Grant 62071073in part by the Fundamental Research Funds for Central Universities under Grant 2023CDJXY-041in part by the Foundation from Guangxi Key Laboratory of Optoelectronic Information Processing under Grant GD20201.
文摘The dynamic avalanche effect is a critical factor influencing the performance and reliability of the field-stop insulated gate bipolar transistors(FS-IGBT).Unclamped inductive switching(UIS)is the primary method for testing the dynamic avalanche capability of FS-IGBTs.Numerous studies have demonstrated that factors such as device structure,avalanche-generating current filaments,and electrical parameters influence the dynamic avalanche effect of the FS-IGBT.However,few studies have focused on enhancing the avalanche reliability of the FS-IGBT by adjusting circuit parameters during operation.In this paper,the dynamic avalanche effect of the FS-IGBT under UIS conditions is comprehensively investigated through a series of comparative experiments with varying circuit parameters,including bus voltage V_(DC),gate voltage V_(G),gate resistance R_(g),load inductance L,and temperature TC.Furthermore,a method to enhance the dynamic avalanche reliability of the FS-IGBT under UIS by optimizing circuit parameters is proposed.In practical applications,reducing gate voltage,increasing load inductance,and lowering temperature can effectively improve the dynamic avalanche capability of the FS-IGBT.
基金Sponsored by the National Natural Science Foundation of China(Grant No.51077032).
文摘The precise mathematical method was adopted to simulate the breakdown process of 5 mm rod and plate electrode gap,which was filled with supercritical nitrogen at the condition of 127 K,4 MPa and seed electron density 1×10^(6) m^(-3) under 29 kV DC voltage.The result shows that the discharge process was completed within 11.8 ns from seed electron triggering,avalanche bulking to streamer extending until gap eventually breakdown.The entire gap breakdown process was divided into three discharge stages,namely,the initial discharge triggered(0-4 ns),avalanche(4-7 ns)and streamer phase(7-11.8 ns).At the same time,the facts were also revealed that the discharge evolution,electric field distribution,and electron density had different values,and also showed different temporal and spatial distribution characteristics along the axis of the discharge gap.Specifically,the discharge characteristics of SCN2 under 1,2,3,4,4.5,and 5 MPa at 127 K were theoretically analyzed respectively,and the microscopic mechanisms of the breakdown process were also detailed.The results indicate that the gas discharge law remained applicable within the 1-3 MPa range.However,the discharge characteristics of supercritical nitrogen at 3.4-5 MPa differed significantly from those at lower pressures,likely attributable to the unique state of matter exhibited by supercritical nitrogen.This study contributes to understanding the discharge mechanism of supercritical nitrogen and offers theoretical guidance for its practical application in the power industry.
基金supported by National Natural Science Foundation of China(NO.42371085)the Tibet Science and Technology Program(XZ202201ZY0011G)the Second Tibetan Plateau Scientific Expedition and Research Program(2019QZKK0906).
文摘Snow avalanches present a significant threat to infrastructure,affecting buildings,roads,railways,and power lines,and frequently leading to massive economic losses in livelihoods and production.With the increase in regional temperatures and the occurrence of extreme snowfall events,the frequency and intensity of avalanches have escalated,resulting in more severe incidents and higher casualty rates.As natural archives of environmental changes,tree rings offer valuable proxies for avalanche hazard assessments in regions where direct observation data is scarce,particularly in high-altitude regions.The dendrogeomorphology has been gradually being applied in avalanche hazard evaluation,however,it remains limited in China.To address this gap,this study systematically investigates the principles and methodologies for reconstructing avalanche histories and evaluates their applications in avalanche hazard assessments through a literature review and field observations.It provides a comprehensive overview of recent advancements in key areas,including the impact of avalanches on forest ecosystems,the reconstruction of avalanches,and the analysis of avalanche events(i.e.,the spatiotemporal distribution,the historical recurrence intervals,magnitudes,and triggering conditions of avalanches).Considering the current limitations in avalanche hazard assessments and the urgent need for such research in China,we outline key priorities and future directions,including refining reconstruction methodologies,developing a comprehensive tree-ring-based avalanche database for high-altitude regions,and establishing an advanced hazard assessment framework based on dendrochronological evidence.
基金supported by the Science Committee of the Ministry of Science and Higher Education of the Republic of Kazakhstan(Grant No.AP19680589).
文摘This research presents a numerical simulation methodology for optimizing circular composite overlays’dimensions and pressure characteristics with orthotropic mechanical properties,specifically,for metal conduits with temperature-dependent elastoplastic behavior.The primary objective of the proposed method is to prevent crack propagation during pressure surges from operational to critical levels.This study examines the“Beineu-Bozoy-Shymkent”steel gas conduit,examining its performance across a temperature range of−40 to+50℃.This work builds on prior research on extended avalanche destruction in steel gas conduits and crack propagation prevention techniques.Theanalysis was conducted using a dynamic finite-element approach with the ANSYS-19.2/ExplicitDynamics software.Simulations of unprotected conduits revealed that increasing gas-dynamic pressure can convert a partial-depth crack into a through-crack,extending longitudinally to approximately seven times its initial length.Notably,at T=+50℃,the developed crack length was 1.2%longer than that at T=−40℃,highlighting the temperature sensitivity of crack progression.The modeling results indicate that crack propagation can be effectively controlled using a circular composite overlay with a thickness between 37.5%and 50%of the crack depth and a length approximately five times that of the initial crack,centered symmetrically over the crack.In addition,preliminary stress analysis indicated that limiting the overlay-induced pressure to 5%of the operational pressure effectively arrested crack growth without generating significant stress concentrations near the overlay boundaries,thereby preventing conduit integrity.
基金supported by the National Natural Science Foundation of China(Grant Nos.42307194 and 42120104002)the Young Elite Scientists Sponsorship Program by CAST(Grant No.2024QNRC001).
文摘The impact of cross-sectional topographic variability on the kinetic properties of granular flows has been underexplored,which hinders the understanding of the kinematics of rock avalanches.In this study,the throat contraction index(T)is introduced to quantify variations in throat topography,and 96 numerical simulation experiments with varying T and slope angles(δ)are conducted.The findings indicate that granular flows experience transient obstructions when traversing throat topographies,primarily due to the periodic formation and breaking of the arch structure.Observations suggest that the acceleration of velocity in the tails of granular flows is restrained by the throat region,potentially altering the dynamics of related geohazards.In this study,the impact of throat topography is quantitatively assessed,demonstrating a reduction in peak flowrates of granular materials by 20%-80% and extending the flowduration up to six times.The present study proposes the throat-induced hazard index(Φ)to evaluate the influenceof throat topography on the risk of rockslides and avalanches characterized by granular flows,which may provide insights for the design of mitigation structures in topographic regions.
基金funded by the Key Science and Technology Project of Transportation Industry(2022-ZD6-090)Xinjiang Transportation Science and Technology Project(2022-ZD-006)+1 种基金Xinjiang Transportation Investment 2021"Unveiling the List of Commander-in-Chief"Science and Technology Project(ZKXFWCG2022060004)the Science and Technology Research and Development Project(KY2022021501)of Xinjiang Transportation Design Institute。
文摘In this study,avalanches in the Aerxiangou section of the Duku Expressway in the Tianshan Mountain area of Xinjiang were taken as the research object,and 92 avalanches were accurately identified through onsite research.A high-resolution three-dimensional model was established by collecting images from unmanned aerial vehicles for an in-depth understanding of the avalanche danger of the region,according to the sample set selection of different uses of machine learning support vector machines to establish the S1-RBFKSVM,S1-PKSVM,S2-RBFKSVM,and S2-PKSVM avalanche susceptibility coupling models.On the basis of the avalanche point susceptibility,the impact velocity,impact force,avalanche volume,and throw distance constitute the hazard evaluation system.The study results revealed that slopes in the range of 26.6°–46.9°are more prone to avalanches,and sample set 2 improved the accuracy by approximately 30%compared with sample set 1 trained in the avalanche susceptibility model.Principal component analysis revealed a total of 16 high-risk avalanches,which were distributed mainly on the southern side of the route.This study provides data support for avalanche simulations as well as early warning and prevention and provides theoretical and methodological guidance for the construction and operation of the Duku Expressway.
基金supported by the National Natural Science Foundation of China(Grant Nos.U2244227,42277126 and 41977215).
文摘Air blasts induced by rock-ice avalanches are common natural phenomena known for their far-field destructive impact.In this study,remote sensing images,eyewitness videos and numerical modelling were comprehensively applied to analyze the initiation and propagation of the 2021 Chamoli avalancheinduced air blast.Our findings indicate that air blasts are observed from the avalanche source area to the Rishiganga valley,but nearly disappear in the Dhauliganga valley.The most intense air blast is concentrated on the left side of Ronti Gad valley,with maximum velocity and pressure estimated at over 70 m/s and 20 kPa,respectively.Such high pressure results in widespread tree breakage in the area.Based on the analysis of the Chamoli event,we further discussed the potential contribution of the avalanche flow regime,avalanche dynamics and geomorphology to the destructive potential of air blasts.Rapidly moved sliding mass can impart the air blast a high initial momentum,and this process will be exaggerated when the avalanche impacts valley walls at bends.However,when the rock-ice avalanche transforms into a debris-enriched flash flood,free water within the flowing mass can displace air,inhibiting the generation of air blasts.Our work offers new insights into the generation and propagation of rock-ice avalanche-induced air blasts,underscoring the importance of including this type of hazard during avalanche risk assessment in high-altitude glacial regions.
基金financially supported by the National Natural Science Foundation of China(Nos.42207197,42293355,41672285,42293350,42341101)the Fundamental Research Funds for the Central Universities(Nos.300102264917,300102262908,590123008)。
文摘Massive granitic rock avalanches are extensively developed in the middle section of the northern Qinling Mountains(NQM),China.The current consensus is that their formation could have been connected with seismic events that occurred in the NQM.However,there is a lack of systematic discussion on the genetic dynamics of these rock avalanches.Hence,taking Earth system scientific research as a starting point,this paper systematically summarizes and discusses development characteristics,formation times and genetic dynamic mechanisms of granitic rock avalanches in the NQM based on geological investigations,high-precision remote sensing interpretations,geomorphological dating,geophysical exploration,and a large-scale shaking table model test.We identified 53 granitic rock avalanches in this area,with a single collapse area ranging from 0.01×10~6 to 1.71×10~6 m^(2).Their development time can be divided into six stages,namely,107000 years BP,11870–11950 years BP,11000 years BP,2300 years BP,1800 years BP,and 1500 years BP,which were closely related to multiple prehistoric or ancient earthquakes.We suggest that long-term coupling of internal and external earth dynamics was responsible for the granitic rock avalanches in the NQM;the internal dynamics were mainly related to subduction,collision and extrusion of different plates under the Qinling terrane,leading to the formation and tectonic uplift of the Qinling orogenic belt;and the external dynamics were closely associated with climate changes resulting in mountain denudation,freeze-thaw cycles and isostatic balance uplift.In this process,the formation and evolution of the Qinling orogenic belt play a geohazard-pregnant role,structural planes,including faults and joints,play a geohazard-controlled role,and earthquakes play a geohazard-induced role,which jointly results in the occurrence of large-scale granitic rock avalanches in the NQM.This research can not only decipher the genetic dynamic mechanism of large hard granitic rock avalanches but also reveal temporal and spatial patterns of the evolution of breeding and the generation of large-scale rock avalanches in the margins of orogenic belts.
基金supported by the National Natural Science Foundation of China(61774152),which are gratefully acknowledged.
文摘Avalanche photodiode(APD)is a kind of photodetector with important applications in optical communication,light detection and ranging(LIDAR)and other fields.APDs fabricated using the recently developed AlGaAsSb as the multiplication material exhibit excellent noise performance.In this work,we report a low-noise separate absorption,grading,charge,and multi-plication(SAGCM)InGaAs/AlGaAsSb APD operating at 1550 nm.A double-mesa structure was fabricated to reduce the dark cur-rent.Numerical simulations were conducted to compare two different mesa-structured APDs.By analyzing the electric field distri-bution,it was found that the electric field at the edge of the multiplication region in the double-mesa APD is nearly 100 kV/cm lower than that of the single-mesa structure.Experimental results demonstrate that after device punch-through,the double-mesa APD’s dark current can be reduced by up to four times compared to the single-mesa APD.Quantitative analysis of the dark current components in the AlGaAsSb APD further confirms that the low sidewall electric field in the double-mesa struc-ture effectively suppresses the trap-assisted tunneling.Additionally,noise measurements indicate a k-value of approximately 0.014,which is significantly lower than that of traditional multiplication materials.This work provides preliminary validation for further performance improvements in low noise and low dark current AlGaAsSb APDs.
基金supported by the Major Scientific and Technological Special Project of Anhui Province(202103a13010004)the Major Scientific and Technological Special Project of Hefei City(2021DX007)the Manufacturing Industry Project of Attracting Talents and Wisdom of Anhui Province(JB24179).
文摘Quantum key distribution(QKD)achieves information-theoretic security based on quantum mechanics principles,where single-photon detectors(SPDs)serve as critical components.This study focuses on the sinusoidal gated SPDs widely used in high-speed QKD systems.We investigate the mechanisms underlying the rising-edge jitter in detection signals,identifying contributions from factors such as the temporal width of injected optical pulses,avalanche generation processes,avalanche signal extraction,and pulse discrimination.To address the issue of excessive jitter-induced bit errors,we propose a retiming scheme that utilizes coincidence signals synchronized with the sinusoidal gating signal.This approach effectively suppresses detection signal jitter and reduces the after-pulse probability of the detector.Experimental validation using a high-precision time-to-digital converter(TDC)demonstrates a significant reduction in the rising-edge jitter distribution after applying the suppression scheme.The proposed method features clear principles and straightforward engineering implementation,avoiding direct interference with the detector’s operational processes.The designed high-speed sinusoidal gated InGaAs/InP SPD operates at 1.25 GHz,achieving a remarkable reduction in after-pulse probability from 10.7%(without jitter suppression)to 0.72%,thereby enhancing the overall performance of QKD systems.
基金supported by the Gansu Provincial Science and Technology Program(22ZD6FA005)the Gansu Postdoctoral Science Foundation(E339880202).
文摘Rapid climate warming is leading to a notable increase in glacier recession and the formation of glacial lakes,which are becoming increasingly characteristic of high mountain regions globally.These severe cryospheric changes critically affect regional water supply,increase geohazards,and threaten lives and livelihoods.This study records regional glaciers and glacial lake dynamics for the period 1990 to 2024,considers the implications of these changes for glacial lake outburst floods(GLOFs)and assesses the potential future flood hazard.Several remotely sensed and reanalysis datasets from 1990 to 2024 are employed to investigate changes in glacier and lake areas.The results highlight a significant reduction in the Manaslu(-0.72±0.20 km^(2)/a)and adjoining glaciers,which led to an increase in the Birendra glacial lake(0.23±0.04 km^(2)/a).Additionally,surface elevation and ice movement data reveal significant thinning of glaciers in the region,averaging-1.52±0.26 m/a,often associated with avalanches near the glacier terminus and triggering GLOFs.Using an HEC-RAS(Hydrologic Engineering Center’s River Analysis System)model,a total extension of 19.3 km of flow channels was revealed,coupled with potential increases in depth,discharge,and velocity,potentially causing massive damage downstream.Regional hazard intensity assessment indicates that five bridges,31 houses,and 1.2 km^(2)of agricultural land may be flooded,with the more populated areas near Samagaun and Banjam being the most affected.Regional climate condition,including significant rising air temperature(0.02℃/a,p<0.05)and declining precipitation(-0.24 mm/a,p<0.05),during recent decades play a crucial role in glacier dynamics and exhibit a significant spatial relation with increased temperature(R^(2)=0.62,α<0.05).Understanding regional cryospheric dynamics and associated risks is therefore essential in designing adaptive mitigation strategies.
基金supported by Continuous-Support Basic Scientific Research Project(No.BJ010261223282)the National Natural Science Foundation of China(Nos.U2167201,11975318)+2 种基金the State Key Laboratory of Nuclear Physics and TechnologyPeking University(No.NPT2023KFY01)the Research and Development Project of China National Nuclear Corporation。
文摘The prompt fission neutron spectrum(PFNS)is a key nuclear data quantity that is of particular interest and plays a crucial role in understanding and modeling fission processes.An array comprising 48 liquid scintillation detectors and a parallelplate avalanche counter(PPAC)was developed at the China Institute of Atomic Energy(CIAE)to measure the PFNS of actinide nuclei.Efficiency and energy calibrations were performed for all the liquid scintillators,and their efficiencies were consistently found to be better than 5%.The time resolutions of the PPAC and liquid scintillators were measured to be 1.08 ns and 1.16 ns using~(252)Cf and~(207)Bi sources,respectively.The pulse shape discrimination of the liquid scintillator was utilized to identify neutron andγsignals on an event-by-event basis,and the figure of merit was deduced as 1.12 at a 200 ke Vee threshold.The contribution to the PFNS from multiple scattered neutrons was evaluated via Geant4 simulations,and those originating from the environment were found to be comparable to the crosstalk between the detectors.The neutron efficiency of the entire detection array was calibrated using a~(252)Cf spontaneous fission source and was demonstrated to be consistent with the Geant4 simulation results,which verified the reliability of the detection array.
基金Project supported by the National Natural Science Foundation of China (Grant No. 62171233)the Natural Science Foundation of Jiangsu Province, China (Grant No. BK20241891)the Jiangsu Province Postgraduate Innovation Program (Grant No. KYCX23_0999)。
文摘A near-infrared(NIR) enhanced silicon single-photon avalanche diode(SPAD) detector is proposed using 0.18 μm bipolar-CMOS-DMOS technology. It is based on a deep multiplication region, formed by a junction between the highvoltage P-well(HVPW) and high-voltage buried N+ layer, to enhance the NIR photon detection probability(PDP). Thanks to the lightly doped P-type epitaxial layer, the electric field in the guard ring is reduced and premature breakdown is prevented. In particular, an extra P-type implantation layer(PIL) is added to the HVPW to reduce the breakdown voltage and enhance the device's sensitivity. Further research on the impact of different PIL sizes on the device performance is carried out. It is experimentally shown that at an excess bias voltage of 5 V, the optimized SPAD achieves a dark count rate of 0.64 cps/μm^(2), peak PDP of 54.8% at 555 nm and PDP of 10.53% at 905 nm. The full width at half-maximum of the timing jitter is 285 ps, and the afterpulsing probability is lower than 1.17%. This novel device provides a practical, low-cost solution for high-performance NIR time-of-flight detectors and 3D imaging sensors.
基金Djordje Spasojevic and Svetislav Mijatovic acknowledge the support from the Ministry of Science,TechnologicalDevelopment and Innovation of the Republic of Serbia(Agreement No.451-03-65/2024-03/200162)S.J.ibid.(Agreement No.451-03-65/2024-03/200122)Bosiljka Tadic from the Slovenian Research Agency(program P1-0044).
文摘Disordered ferromagnets with a domain structure that exhibit a hysteresis loop when driven by the external magnetic field are essential materials for modern technological applications.Therefore,the understanding and potential for controlling the hysteresis phenomenon in thesematerials,especially concerning the disorder-induced critical behavior on the hysteresis loop,have attracted significant experimental,theoretical,and numerical research efforts.We review the challenges of the numerical modeling of physical phenomena behind the hysteresis loop critical behavior in disordered ferromagnetic systems related to the non-equilibriumstochastic dynamics of domain walls driven by external fields.Specifically,using the extended Random Field Ising Model,we present different simulation approaches and advanced numerical techniques that adequately describe the hysteresis loop shapes and the collective nature of the magnetization fluctuations associated with the criticality of the hysteresis loop for different sample shapes and varied parameters of disorder and rate of change of the external field,as well as the influence of thermal fluctuations and demagnetizing fields.The studied examples demonstrate how these numerical approaches reveal newphysical insights,providing quantitativemeasures of pertinent variables extracted from the systems’simulated or experimentally measured Barkhausen noise signals.The described computational techniques using inherent scale-invariance can be applied to the analysis of various complex systems,both quantum and classical,exhibiting non-equilibrium dynamical critical point or self-organized criticality.
基金The Natural Science Foundation of Jiangsu Province(No.BK2012559)Qing Lan Project of Jiangsu Province
文摘Based on an avalanche photodiode（ APD） detecting array working in Geiger mode（ GM-APD）, a high-performance infrared sensor readout integrated circuit（ ROIC） used for infrared 3D（ three-dimensional） imaging is proposed. The system mainly consists of three functional modules, including active quenching circuit（ AQC）, time-to-digital converter（ TDC） circuit and other timing controller circuit. Each AQC and TDC circuit together constitutes the pixel circuit. Under the cooperation with other modules, the current signal generated by the GM-APD sensor is detected by the AQC, and the photon time-of-flight（ TOF） is measured and converted to a digital signal output to achieve a better noise suppression and a higher detection sensitivity by the TDC. The ROIC circuit is fabricated by the CSMC 0. 5 μm standard CMOS technology. The array size is 8 × 8, and the center distance of two adjacent cells is 100μm. The measurement results of the chip showthat the performance of the circuit is good, and the chip can achieve 1 ns time resolution with a 250 MHz reference clock, and the circuit can be used in the array structure of the infrared detection system or focal plane array（ FPA）.
