A method is presented for determining instant values of Earth’s polar motion(PM)using a set of lunar laser ranging(LLR)measurements acquired simultaneously by tri-static common view(TCV)at three LLR stations in Europ...A method is presented for determining instant values of Earth’s polar motion(PM)using a set of lunar laser ranging(LLR)measurements acquired simultaneously by tri-static common view(TCV)at three LLR stations in Europe.We developed a model of the LLR TCV measurements,then formulated the linear equation for solving PM.Although there was no actual TCV event in the data,we conducted a two-phase study to test our method using actual LLR normal points(NPs)acquired by the European stations during 2012-2022.In the first phase,we simulated TCV events and PM solutions.The robustness of our method was assessed by introducing Universal Time(UT1)errors and per-station range errors in this phase.In the second phase,we augmented the actual LLR NPs with simulated data to generate realistic TCV events and solutions,using the‘1+2’and‘2+1’strategies,which differed in terms of data composition.Results indicated that a UT1 error of 0.1 ms caused PM errors of<18 mas,while a uniform range error of 50 mm resulted in PM errors of<180 mas.In the augmentation phase,the maximum solution errors were 752 and 899 mas,and 88.5% and 91.2% of the solutions were better than the predictions for the‘1+2’and‘2+1’strategies,respectively.The presented approach relies on precise geodetic data,and therefore,it is not intended to replace the traditional method.However,this study demonstrated that instant determination of PM is feasible and robust,although the accuracy requires further enhancement.展开更多
This paper provides a comprehensive overview of the development of Lunar Laser Ranging(LLR),covering key components such as ground observatories,lunar retro-reflectors,and data formats.The paper details the evolution ...This paper provides a comprehensive overview of the development of Lunar Laser Ranging(LLR),covering key components such as ground observatories,lunar retro-reflectors,and data formats.The paper details the evolution of LLR experiments conducted by some major world-class observatories,with a particular focus on addressing critical issues associated with LLR technology.Additionally,the article highlights the latest advancements in the field,elucidating scientific achievements derived from LLR data,including its contributions to gravitational theory,Earth Orientation Parameters,lunar physics exploration,and lunar librations.The review summarizes new challenges in LLR modeling and concludes with prospects for the future development of LLR.展开更多
Pedestrian positioning system(PPS)using wearable inertial sensors has wide applications towards various emerging fields such as smart healthcare,emergency rescue,soldier positioning,etc.The performance of traditional ...Pedestrian positioning system(PPS)using wearable inertial sensors has wide applications towards various emerging fields such as smart healthcare,emergency rescue,soldier positioning,etc.The performance of traditional PPS is limited by the cumulative error of inertial sensors,complex motion modes of pedestrians,and the low robustness of the multi-sensor collaboration structure.This paper presents a hybrid pedestrian positioning system using the combination of wearable inertial sensors and ultrasonic ranging(H-PPS).A robust two nodes integration structure is developed to adaptively combine the motion data acquired from the single waist-mounted and foot-mounted node,and enhanced by a novel ellipsoid constraint model.In addition,a deep-learning-based walking speed estimator is proposed by considering all the motion features provided by different nodes,which effectively reduces the cumulative error originating from inertial sensors.Finally,a comprehensive data and model dual-driven model is presented to effectively combine the motion data provided by different sensor nodes and walking speed estimator,and multi-level constraints are extracted to further improve the performance of the overall system.Experimental results indicate that the proposed H-PPS significantly improves the performance of the single PPS and outperforms existing algorithms in accuracy index under complex indoor scenarios.展开更多
The vehicles and pedestrians ranging is one of the basic functions of advanced driving assistance system.However,most of the ranging systems can only work on workstations with high computing power.To solve this proble...The vehicles and pedestrians ranging is one of the basic functions of advanced driving assistance system.However,most of the ranging systems can only work on workstations with high computing power.To solve this problem,a lightweight algorithm is proposed to be packaged into Android application package,and be installed in Android smartphones for vehicles and pedestrians ranging.The proposed ranging system is based on the images obtained by smartphone’s monocular camera.To achieve real-time ranging,an 8-bit integer(int8)quantization algorithm is proposed to accelerate the inference of convolutional neural networks.To increase the detection precision,a zoom-in algorithm is further proposed to detect small targets in the distance.After having detected the 2D bounding boxes of vehicles and pedestrians,a pinhole ranging method is applied to estimate the distance.In order to verify the proposed algorithm,the mean average precision(mAP)and the frame per second(FPS)are first tested by using COCO dataset on Huawei P40Pro,then,the ranging precision on the real road.The experimental results show that this algorithm can successfully perform real-time ranging(15 FPS)with high precision(34.8 mAP)onto the tested smartphones.Finally,a possible mobile application based on the ranging algorithm,i.e.,distance keeping warning,is also provided.展开更多
Resonant linear and nonlinear properties in terahertz range of 2D materials graphene and silicene placed into a bias magnetic field are investigated theoretically on the base of the quasi-classical kinetic theory. Whe...Resonant linear and nonlinear properties in terahertz range of 2D materials graphene and silicene placed into a bias magnetic field are investigated theoretically on the base of the quasi-classical kinetic theory. When the electromagnetic frequency is close to the cyclotron one, the linear conductivity increases two orders. Under the resonant frequencies nonlinearity becomes essential at low magnitudes of terahertz electric fields. In absence of a bias magnetic field the nonlinear dependences of the surface electric currents on terahertz electric field are practically the same simulated from kinetics and electron hydrodynamics with nonzero “kinetic” electron effective mass. Graphene possesses higher values of nonlinearity of the resonant conductivity, whereas in absence of a bias magnetic field, the electron nonlinearity is higher in silicene.展开更多
The Fringe Projection Profilometry(FPP)system with a single exposure time or a single projection intensity is limited by the dynamic range of the camera,which can lead to overexposure and underexposure of the image,re...The Fringe Projection Profilometry(FPP)system with a single exposure time or a single projection intensity is limited by the dynamic range of the camera,which can lead to overexposure and underexposure of the image,resulting in point cloud loss or reduced accuracy.To address this issue,unlike the pixel modulation method of projectors,we utilize the characteristics of color projectors where the intensity of the three-channel LED can be controlled independently.We propose a method for separating the projector's three-channel light intensity,combined with a color camera,to achieve single exposure and multi-intensity image acquisition.Further,the crosstalk coefficient is applied to predict the three-channel reflectance of the measured object.By integrating clustering and channel mapping,we establish a pixel-level mapping model between the projector's three-channel current and the camera's three-channel image intensity,which realizes the optimal projection current prediction and the high dynamic range(HDR)image acquisition.The proposed method allows for high-precision three-dimensional(3D)data acquisition of HDR scenes with a single exposure.The effectiveness of this method has been validated through experiments with standard planes and standard steps,showing a significant reduction in mean absolute error(44.6%)compared to existing singleexposure HDR methods.Additionally,the number of images required for acquisition is significantly reduced(by 70.8%)compared to multi-exposure fusion methods.This proposed method has great potential in various FPP-related fields.展开更多
PLP City Range项目坐落在曼谷通罗地区一个宁静的高档社区内,是一座为尖端高尔夫模拟中心建造的创新性混合用途建筑。引人注目的建筑立面,采用曲面预制混凝土板正反向拼贴组合而成,兼具美学和功能性。这些造型独特的混凝土模块在自然...PLP City Range项目坐落在曼谷通罗地区一个宁静的高档社区内,是一座为尖端高尔夫模拟中心建造的创新性混合用途建筑。引人注目的建筑立面,采用曲面预制混凝土板正反向拼贴组合而成,兼具美学和功能性。这些造型独特的混凝土模块在自然光下形成光影交织的效果,巧妙地呼应了高尔夫运动挥杆时的优雅弧线,在视觉上呈现这项运动独特的魅力。展开更多
Vibration detection using sensors with both wide working frequency range,good sensitivity,and other good performances is a topic of great interest in fields such as inertial navigation,deep-sea fishing boat engines co...Vibration detection using sensors with both wide working frequency range,good sensitivity,and other good performances is a topic of great interest in fields such as inertial navigation,deep-sea fishing boat engines condition monitoring,seismic monitoring,attitude,and heading reference system,etc.This paper investigates two 6H-SIC MEMS diaphragms,one triangular and the other square,used in a fiber optic Fabry–Perot(FP)accelerometer in an experimental scenario.The triangular chip shows a wide working frequency range of 630 Hz–5300 Hz,a natural frequency of 44.3 k Hz,and a mechanical sensitivity of 0.154 nm/g.An optimal structure of the square chip used in a probe such as a fiber optic FP accelerometer also shows a wide working frequency range of 120 Hz–2300 Hz;a good sensitivity of 31.5 m V/g,a resonance frequency of7873 Hz,an accuracy of 0.96%F.S.,a frequency measurement error of 1.15%,and an excellent linearity of 0.9995.展开更多
Two-dimensional(2D)organic-inorganic hybrid perovskites(OIHPs)have been developed as promising candidates for photodetection,owing to their excellent semiconducting features and structural tunability.However,as an imp...Two-dimensional(2D)organic-inorganic hybrid perovskites(OIHPs)have been developed as promising candidates for photodetection,owing to their excellent semiconducting features and structural tunability.However,as an important parameter for photodetection,the photoresponsive range of 2D OIHPs is usually modulated by finite metal-halide combinations,constraining their further development.The emerging aromatic amine-based alternating-cations-interlayered(A-ACI)hybrid perovskites that exhibit excellent charge transport and additional interlayered structural designability,provide an extra solution for achieving ideal photoresponsive range.Herein,for the first time,the photoresponsive range is successfully broadened in A-ACI hybrid perovskites(NMA)_(4)(FA)_(2)Pb_(3)Br_(12)(2)remolding from(NMA)_(4)(MA)_(2)Pb_(3)Br_(12)(1)(NMA=N-methylbenzylaminium,FA=formamidinium and MA=methylammonium).Particularly,1 and 2adopt an unprecedented configuration that NMA and MA/FA are alternately arranged in the interlayer in a 4:2 manner.Importantly,2 exhibits a narrower bandgap than 1,which can be ascribed to the lowlying conduct band composed of intercalation FAπ*orbitals.Meanwhile,2 possesses a shorter interlayer distance and flatter inorganic skeleton,synergistically facilitating the wider photo-absorption range and further endowing a broadening photoresponsive range(70 nm).This research not only enriches the perovskite family but also provides insights into structure-property relationships.展开更多
Ammonium level in body fluids serves as one of the critical biomarkers for healthcare,especially those relative to liver diseases.The continuous and real-time monitoring in both invasive and noninvasive manners is hig...Ammonium level in body fluids serves as one of the critical biomarkers for healthcare,especially those relative to liver diseases.The continuous and real-time monitoring in both invasive and noninvasive manners is highly desired,while the ammonium concentrations vary largely in different body fluids.Besides,the sensing reliability based on ion-selective biosensors can be significantly interfered by potassium ions.To tackle these challenges,a flexible and biocompatible sensing patch for wireless ammonium level sensing was reported with an ultrawide linear range for universal body fluids including blood,tears,saliva,sweat and urine.The as-prepared biocompatible sensors deliver a reliable sensitivity of 58.7 mV decade-1 in the range of 1-100 mM and a desirable selectivity coefficient of 0.11 in the interference of potassium ions,attributed to the cross-calibration within the sensors array.The sensor’s biocompatibility was validated by the cell growth on the sensor surface(>80%),hemolysis rates(<5%),negligible cellular inflammatory responses and weight changes of the mice with implanted sensors.Such biocompatible sensors with ultrawide linear range and desirable selectivity open up new possibility of highly compatible biomarker analysis via different body fluids in versatile approaches.展开更多
Mueller matrix polarimetry(MMP)has been proven to be a powerful tool for characterizing the microstructural features of biological samples in biomedical research and clinical diagnostics.However,the traditional Muelle...Mueller matrix polarimetry(MMP)has been proven to be a powerful tool for characterizing the microstructural features of biological samples in biomedical research and clinical diagnostics.However,the traditional Mueller matrix(MM)imaging technique based on single exposure has a limited dynamic range,leading to poor polarization image quality for biological samples with signi-cant contrast variations.In this study,we propose a novel method to generate high dynamic range(HDR)MM images based on a multi-exposure fusion algorithm.By employing an optimal exposure selection strategy for transmission imaging and a multi-exposure weighted averaging strategy for backscattering imaging,the method expands the dynamic range while accurately preserving the polarization information of the samples.Experiments of sliced and bulk tissues demonstrate that the proposed method signi¯cantly suppresses the scattering noise and improves the quality of extracted polarization parameter images,especially in accurate distinction of di®erent pathological areas.These results highlight the potential of HDR MM imaging technology in extracting polarization information from complex biological samples with high resolution and contrast.展开更多
Electronic skin has showcased superior sensing capabilities inspired from human skin.However,most preceding studies focused on the dermis of the skin rather than the epidermis.In particular,the pseudo-porous structura...Electronic skin has showcased superior sensing capabilities inspired from human skin.However,most preceding studies focused on the dermis of the skin rather than the epidermis.In particular,the pseudo-porous structural domain of the epidermis increases the skin's tolerance while ensuring its susceptibility to touch.Yet,most endeavors on the porous structures failed to replicate the superior sensing performance of skin-like counterparts in terms of sensitivity and/or detection range.Stimulated by the strategy that the epidermis of the skin absorbs energy while producing ionic conduction to the nerves,this work initiatively introduced an easy-to-produce,and low-cost pressure sensor based on ionic-gel foam,and achieved a high sensitivity(2893 kPa^(-1))within a wide pressure range(up to~1 MPa),which ranked among the best cases thus far.Moreover,the factors affecting the sensor performance were explored while the sensing principles were enriched.Inspiringly,the plantar pressure measurement by harnessing the as-prepared sensor unveiled an ultra-broad detection range(100 Pa-1 MPa),thus delivering a huge application potential in the field of robot and health monitoring.展开更多
To determine the geological age,petrogenesis,and tectonic setting of Mesozoic volcanic rocks in the Ningyuancun Formation in Xunke area,Lesser Hinggan Range,the zircon U-Pb geochronology,petrographic observations,and ...To determine the geological age,petrogenesis,and tectonic setting of Mesozoic volcanic rocks in the Ningyuancun Formation in Xunke area,Lesser Hinggan Range,the zircon U-Pb geochronology,petrographic observations,and geochemical analyses of major and trace elements were conducted in this study.Zircon U-Pb dating showed that the volcanic rocks of the Ningyuancun Formation were formed in the Early Cretaceous(112.97±0.90 Ma).Major element analyses revealed that the content of SiO_(2)weighted from 74.14%to 76.54%,indicating the volcanic rocks to be high-silica and felsic.The content of Al_(2)O_(3)varies from 12.48%to 13.65%.A total alkali content of the volcanic rocks range between 8.46%and 9.56%,with Na_(2)O/K_(2)O ratios from 0.69 to 0.89.This indicated that the volcanic rocks belonged to a highly differentiated calc-alkaline series.Additionally,A/CNK values range from 0.950 to 1.015,and A/NK values vary between 0.999 and 1.127,suggesting a peraluminous characteristic.Trace element analysis showed a right-sloping“V-shaped”REE pattern,with the enrichment in light REEs and a prominent negative anomaly of Eu.The volcanic rocks are enriched in Rb,Th,U,La,and Ce,while Ba,Sr,and Ti are depleted.Rb/Sr ratio ranges from 10.01 to 12.46,Ti/Y ratio is from 51.14 to 95.72,and Ti/Zr ratio is from 5.78 to 6.41.It is suggested that the magma was derived from the partial melting of crustal rocks.This evidenced that the Early Cretaceous high-silica rhyolites were formed in an intracontinental extension in eastern Northeast China during the northwestward subduction of the Pacific Plate.The crustal extension,asthenospheric mantle upwelling and underplating of mantle-derived magmas resulted in the residual crystalline mush in Early Cretaceous mafic magma chambers to erupt.展开更多
Geodetic observations over the past several decades identify the Tien Shan as a prominent and active intracontinental mountain belt,characterized by a meridional shortening rate of up to 20 mm/a.The region has experie...Geodetic observations over the past several decades identify the Tien Shan as a prominent and active intracontinental mountain belt,characterized by a meridional shortening rate of up to 20 mm/a.The region has experienced significant seismic events,particularly along its northern boundary,highlighting the recurrent seismic activity in the Kyrgyz Republic.The Issyk-Ata fault,stretching 120 km from west to east in the northern Tien Shan,bounds from the north a young,growing anticline demarcating the foothills of the Kyrgyz Range and the Chui depression.This region is susceptible to strong earthquakes,posing a significant threat to the Chui region and Bishkek,the capital city with over a million residents.The youngest fault in the area is the Issyk-Ata fault,traversing the southern part of Bishkek,where modern construction has obscured its features.This study integrates remote sensing,detailed fieldwork,and paleoseismological investigations to map and analyze surface ruptures,quantify vertical displacements,and assess seismic hazards along the Issyk-Ata fault.Using optically stimulated luminescence and radiocarbon dating,we determined ages for documented paleoseismic events,placing two ancient earthquakes in the Holocene.Magnitude estimates suggest seismic events with magnitudes ranging from 6.6 to 7.1.In the Dzhal area,geological and geomorphological analysis yielded a longterm fault-slip rate of 1.15 mm/a.The Issyk-Ata fault shows variable rupture behavior,with distinct segments demonstrating different seismic characteristics and histories of activity.This variability necessitates comprehensive seismic hazard modeling to better understand and mitigate potential risks in the region.展开更多
High-voltage dual-ion batteries(DIBs)face significant challenges,including graphite cathode degradation,cathode-electrolyte interphase(CEI)instability,and the thermodynamic instability of conventional carbonate-based ...High-voltage dual-ion batteries(DIBs)face significant challenges,including graphite cathode degradation,cathode-electrolyte interphase(CEI)instability,and the thermodynamic instability of conventional carbonate-based electrolytes,particularly at extreme temperatures.In this study,we develop a stable electrolyte incorporating lithium difluorophosphate(LiDFP)as an additive to enhance the electrochemical performance of DIBs over a wide temperature range.LiDFP preferentially decomposes to form a rapid anion-transporting,mechanically robust CEI layer on graphite,which provides better protection by suppressing graphite's volume expansion,preventing electrolyte oxidative decomposition,and enhancing reaction kinetics.As a result,Li||graphite half cells using LiDFP electrolyte exhibit outstanding rate performance(90.8% capacity retention at 30 C)and excellent cycle stability(82.2% capacity retention after 5000 cycles)at room temperature.Moreover,graphite||graphite full cells with LiDFP electrolyte demonstrate stable discharge capacity across a temperature range of-20 to 40℃,expanding the potential applications of LiDFP.This work establishes a novel strategy for optimizing the interphase through electrolyte design,paving the way for all-climate DIBs with improved performance and stability.展开更多
Anthropogenic climate change is altering species distributions globally.While species distributions are expected to shift to higher latitudes and elevations under global warming,empirical evidence on distribution shif...Anthropogenic climate change is altering species distributions globally.While species distributions are expected to shift to higher latitudes and elevations under global warming,empirical evidence on distribution shifts is mixed,and factors mediating the direction and magnitude of range shifts remain unclear.Using a dataset of 132new provincial records for 96 resident bird species from 2000 to 2023,we measured geographic distance,latitudinal shift,and temperature shift from each new record to the historical range for each species to test for poleward shifts.We assessed taxonomic variation in the magnitude of range shifts and used phylogenetic generalized linear mixed models to quantify relationships between species traits and the extent of range shifts.Our results revealed that new records occurred at a mean geographic distance of 420 km from historical ranges,with mean latitudinal shifts of+1.68°(poleward)and temperature shifts of-1.33℃(toward colder climates).The magnitude of geographic range shifts was strongly constrained by phylogenetic relatedness.Habitat breadth,habitat openness,and centroid latitude of historical ranges emerged as significant predictors of range shifts.Our results suggest that resident bird species'geographic ranges in China are shifting poleward,but the magnitude of these shifts is non-random across lineages.Species with broader habitat preferences and those from warmer climates are more likely to shift farther from their historical ranges and toward higher latitudes.This study emphasizes taxonomic variation in species range shifts and highlights the need for species-and site-specific conservation strategies under global warming.展开更多
The high-speed reentry vehicle operates across a broad range of speeds and spatial domains,where optimal aerodynamic shapes for different speeds are contradictory.This makes it challenging for a single-Mach optimizati...The high-speed reentry vehicle operates across a broad range of speeds and spatial domains,where optimal aerodynamic shapes for different speeds are contradictory.This makes it challenging for a single-Mach optimization design to meet aerodynamic performance requirements throughout the vehicle’s flight envelope.Additionally,the strong coupling between aerodynamics and control adds complexity,as fluctuations in aerodynamic parameters due to speed variations complicate control system design.To address these challenges,this study proposes an aerodynamic/control coupling optimization design approach.This method,based on aerodynamic optimization principles,incorporates active control technology,treating aerodynamic layout and control system design as primary components during the conceptual design phase.By integrating the design and evaluation of aerodynamics and control,the approach aims to reduce design iterations and enhance overall flight performance.The comprehensive design of the rotary reentry vehicle,using this optimization strategy,effectively balances performance at supersonic and hypersonic speeds.The results show that the integrated design model meets aerodynamic and control performance requirements over a broader range of Mach numbers,preventing performance degradation due to deviations from the design Mach number,and providing a practical solution for high-speed reentry vehicle design.展开更多
Large dynamic range and ultra-wideband receiving abilities are significant for many receivers. With these abilities, receivers can obtain signals with different power in ultra-wideband frequency space without informat...Large dynamic range and ultra-wideband receiving abilities are significant for many receivers. With these abilities, receivers can obtain signals with different power in ultra-wideband frequency space without information loss. However, conventional receiving scheme is hard to have large dynamic range and ultra-wideband receiving simultaneously because of the analog-to-digital converter(ADC) dynamic range and sample rate limitations. In this paper, based on the modulated sampling and unlimited sampling, a novel receiving scheme is proposed to achieve large dynamic range and ultra-wideband receiving. Focusing on the single carrier signals, the proposed scheme only uses a single self-rest ADC(SR-ADC) with low sample rate, and it achieves large dynamic range and ultra-wideband receiving simultaneously. Two receiving scenarios are considered, and they are cooperative strong signal receiving and non-cooperative strong/weak signals receiving. In the cooperative receiving scenario, an improved fast recovery method is proposed to obtain the modulated sampling output. In the non-cooperative receiving scenario, the strong and weak signals with different carrier frequencies are considered, and the signal processing method can recover and estimate each signal. Simulation results show that the proposed scheme can realize large dynamic range and ultra-wideband receiving simultaneously when the input signal-to-noise(SNR) ratio is high.展开更多
High-performance flexible pressure sensors have garnered significant attention in fields such as wearable electronics and human-machine interfaces.However,the development of flexible pressure sensors that simultaneous...High-performance flexible pressure sensors have garnered significant attention in fields such as wearable electronics and human-machine interfaces.However,the development of flexible pressure sensors that simultaneously achieve high sensitivity,a wide detection range,and good mechanical stability remains a challenge.In this paper,we propose a flexible piezoresistive pressure sensor based on a Ti_(3)C_(2)Tx(MXene)/polyethylene oxide(PEO)composite nanofiber membrane(CNM).The sensor,utilizing MXene(0.4 wt%)/PEO(5 wt%),exhibits high sensitivity(44.34 kPa^(−1)at 0−50 kPa,12.99 kPa^(−1)at 50−500 kPa)and can reliably monitor physiological signals and other subtle cues.Moreover,the sensor features a wide detection range(0−500 kPa),fast response and recovery time(~150/45 ms),and excellent mechanical stability(over 10000 pressure cycles at maximum load).Through an MXene/PEO sensor array,we demonstrate its applications in human physiological signal monitoring,providing a reliable way to expand the application of MXene-based flexible pressure sensors.展开更多
基金supported by the National Natural Science Foundation of China(NSFC)(11673082 and 11903059).
文摘A method is presented for determining instant values of Earth’s polar motion(PM)using a set of lunar laser ranging(LLR)measurements acquired simultaneously by tri-static common view(TCV)at three LLR stations in Europe.We developed a model of the LLR TCV measurements,then formulated the linear equation for solving PM.Although there was no actual TCV event in the data,we conducted a two-phase study to test our method using actual LLR normal points(NPs)acquired by the European stations during 2012-2022.In the first phase,we simulated TCV events and PM solutions.The robustness of our method was assessed by introducing Universal Time(UT1)errors and per-station range errors in this phase.In the second phase,we augmented the actual LLR NPs with simulated data to generate realistic TCV events and solutions,using the‘1+2’and‘2+1’strategies,which differed in terms of data composition.Results indicated that a UT1 error of 0.1 ms caused PM errors of<18 mas,while a uniform range error of 50 mm resulted in PM errors of<180 mas.In the augmentation phase,the maximum solution errors were 752 and 899 mas,and 88.5% and 91.2% of the solutions were better than the predictions for the‘1+2’and‘2+1’strategies,respectively.The presented approach relies on precise geodetic data,and therefore,it is not intended to replace the traditional method.However,this study demonstrated that instant determination of PM is feasible and robust,although the accuracy requires further enhancement.
基金supported by the National Key Research and Development Program of China (2021YFA0715101)the National Natural Science Foundation of China (12033009, 12103087)+4 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences (XDA0350300)the International Partnership Program of Chinese Academy of Sciences (020GJHZ2022034FN)the Yunnan Fundamental Research Projects (202201AU070225, 202301AT070328, 202401AT070141)the Young Talent Project of Yunnan Revitalization Talent Support Programsupported by ESA (European Space Agency) under the ESA-INFN contract n. 4000133721/21/NL/CR and by ASI (Agenzia Spaziale Italiana) under the Research Agreement n. 2019-15-HH.0
文摘This paper provides a comprehensive overview of the development of Lunar Laser Ranging(LLR),covering key components such as ground observatories,lunar retro-reflectors,and data formats.The paper details the evolution of LLR experiments conducted by some major world-class observatories,with a particular focus on addressing critical issues associated with LLR technology.Additionally,the article highlights the latest advancements in the field,elucidating scientific achievements derived from LLR data,including its contributions to gravitational theory,Earth Orientation Parameters,lunar physics exploration,and lunar librations.The review summarizes new challenges in LLR modeling and concludes with prospects for the future development of LLR.
基金supported by the National Natural Science Foundation of China under(Grant No.52175531)in part by the Science and Technology Research Program of Chongqing Municipal Education Commission under Grant(Grant Nos.KJQN202000605 and KJZD-M202000602)。
文摘Pedestrian positioning system(PPS)using wearable inertial sensors has wide applications towards various emerging fields such as smart healthcare,emergency rescue,soldier positioning,etc.The performance of traditional PPS is limited by the cumulative error of inertial sensors,complex motion modes of pedestrians,and the low robustness of the multi-sensor collaboration structure.This paper presents a hybrid pedestrian positioning system using the combination of wearable inertial sensors and ultrasonic ranging(H-PPS).A robust two nodes integration structure is developed to adaptively combine the motion data acquired from the single waist-mounted and foot-mounted node,and enhanced by a novel ellipsoid constraint model.In addition,a deep-learning-based walking speed estimator is proposed by considering all the motion features provided by different nodes,which effectively reduces the cumulative error originating from inertial sensors.Finally,a comprehensive data and model dual-driven model is presented to effectively combine the motion data provided by different sensor nodes and walking speed estimator,and multi-level constraints are extracted to further improve the performance of the overall system.Experimental results indicate that the proposed H-PPS significantly improves the performance of the single PPS and outperforms existing algorithms in accuracy index under complex indoor scenarios.
基金the RoboCar Project for Internationalization of RTI Projects within the Frame of the Austrian Research Promotion Agency(No.861000)。
文摘The vehicles and pedestrians ranging is one of the basic functions of advanced driving assistance system.However,most of the ranging systems can only work on workstations with high computing power.To solve this problem,a lightweight algorithm is proposed to be packaged into Android application package,and be installed in Android smartphones for vehicles and pedestrians ranging.The proposed ranging system is based on the images obtained by smartphone’s monocular camera.To achieve real-time ranging,an 8-bit integer(int8)quantization algorithm is proposed to accelerate the inference of convolutional neural networks.To increase the detection precision,a zoom-in algorithm is further proposed to detect small targets in the distance.After having detected the 2D bounding boxes of vehicles and pedestrians,a pinhole ranging method is applied to estimate the distance.In order to verify the proposed algorithm,the mean average precision(mAP)and the frame per second(FPS)are first tested by using COCO dataset on Huawei P40Pro,then,the ranging precision on the real road.The experimental results show that this algorithm can successfully perform real-time ranging(15 FPS)with high precision(34.8 mAP)onto the tested smartphones.Finally,a possible mobile application based on the ranging algorithm,i.e.,distance keeping warning,is also provided.
文摘Resonant linear and nonlinear properties in terahertz range of 2D materials graphene and silicene placed into a bias magnetic field are investigated theoretically on the base of the quasi-classical kinetic theory. When the electromagnetic frequency is close to the cyclotron one, the linear conductivity increases two orders. Under the resonant frequencies nonlinearity becomes essential at low magnitudes of terahertz electric fields. In absence of a bias magnetic field the nonlinear dependences of the surface electric currents on terahertz electric field are practically the same simulated from kinetics and electron hydrodynamics with nonzero “kinetic” electron effective mass. Graphene possesses higher values of nonlinearity of the resonant conductivity, whereas in absence of a bias magnetic field, the electron nonlinearity is higher in silicene.
文摘The Fringe Projection Profilometry(FPP)system with a single exposure time or a single projection intensity is limited by the dynamic range of the camera,which can lead to overexposure and underexposure of the image,resulting in point cloud loss or reduced accuracy.To address this issue,unlike the pixel modulation method of projectors,we utilize the characteristics of color projectors where the intensity of the three-channel LED can be controlled independently.We propose a method for separating the projector's three-channel light intensity,combined with a color camera,to achieve single exposure and multi-intensity image acquisition.Further,the crosstalk coefficient is applied to predict the three-channel reflectance of the measured object.By integrating clustering and channel mapping,we establish a pixel-level mapping model between the projector's three-channel current and the camera's three-channel image intensity,which realizes the optimal projection current prediction and the high dynamic range(HDR)image acquisition.The proposed method allows for high-precision three-dimensional(3D)data acquisition of HDR scenes with a single exposure.The effectiveness of this method has been validated through experiments with standard planes and standard steps,showing a significant reduction in mean absolute error(44.6%)compared to existing singleexposure HDR methods.Additionally,the number of images required for acquisition is significantly reduced(by 70.8%)compared to multi-exposure fusion methods.This proposed method has great potential in various FPP-related fields.
文摘PLP City Range项目坐落在曼谷通罗地区一个宁静的高档社区内,是一座为尖端高尔夫模拟中心建造的创新性混合用途建筑。引人注目的建筑立面,采用曲面预制混凝土板正反向拼贴组合而成,兼具美学和功能性。这些造型独特的混凝土模块在自然光下形成光影交织的效果,巧妙地呼应了高尔夫运动挥杆时的优雅弧线,在视觉上呈现这项运动独特的魅力。
基金Project supported by the National Natural Science Foundation of China(Grant No.32473216)Ningbo Youth Science and Technology Innovation Leading Talent Project(Grant No.2023QL004)。
文摘Vibration detection using sensors with both wide working frequency range,good sensitivity,and other good performances is a topic of great interest in fields such as inertial navigation,deep-sea fishing boat engines condition monitoring,seismic monitoring,attitude,and heading reference system,etc.This paper investigates two 6H-SIC MEMS diaphragms,one triangular and the other square,used in a fiber optic Fabry–Perot(FP)accelerometer in an experimental scenario.The triangular chip shows a wide working frequency range of 630 Hz–5300 Hz,a natural frequency of 44.3 k Hz,and a mechanical sensitivity of 0.154 nm/g.An optimal structure of the square chip used in a probe such as a fiber optic FP accelerometer also shows a wide working frequency range of 120 Hz–2300 Hz;a good sensitivity of 31.5 m V/g,a resonance frequency of7873 Hz,an accuracy of 0.96%F.S.,a frequency measurement error of 1.15%,and an excellent linearity of 0.9995.
基金financially supported by the National Natural Science Foundation of China(Nos.22435005,22193042,21921001,52202194,22305105,22201284)the Key Research Program of Frontier Sciences of the Chinese Academy of Sciences(No.ZDBSLY-SLH024)。
文摘Two-dimensional(2D)organic-inorganic hybrid perovskites(OIHPs)have been developed as promising candidates for photodetection,owing to their excellent semiconducting features and structural tunability.However,as an important parameter for photodetection,the photoresponsive range of 2D OIHPs is usually modulated by finite metal-halide combinations,constraining their further development.The emerging aromatic amine-based alternating-cations-interlayered(A-ACI)hybrid perovskites that exhibit excellent charge transport and additional interlayered structural designability,provide an extra solution for achieving ideal photoresponsive range.Herein,for the first time,the photoresponsive range is successfully broadened in A-ACI hybrid perovskites(NMA)_(4)(FA)_(2)Pb_(3)Br_(12)(2)remolding from(NMA)_(4)(MA)_(2)Pb_(3)Br_(12)(1)(NMA=N-methylbenzylaminium,FA=formamidinium and MA=methylammonium).Particularly,1 and 2adopt an unprecedented configuration that NMA and MA/FA are alternately arranged in the interlayer in a 4:2 manner.Importantly,2 exhibits a narrower bandgap than 1,which can be ascribed to the lowlying conduct band composed of intercalation FAπ*orbitals.Meanwhile,2 possesses a shorter interlayer distance and flatter inorganic skeleton,synergistically facilitating the wider photo-absorption range and further endowing a broadening photoresponsive range(70 nm).This research not only enriches the perovskite family but also provides insights into structure-property relationships.
基金supported by the National Natural Science Foundation of China(62201243)Natural Science Foundation of Guangdong Province(2022A1515011928)+2 种基金Shenzhen Science and Technology Program(Grant No.RCYX20231211090432060,JSGGZD20220822095600001)Postgraduate Scientific Research Innovation Project of Hunan Province(CX20231306)the technical support from the Southern University of Science and Technology Core Research Facilities(SUSTech CRF)。
文摘Ammonium level in body fluids serves as one of the critical biomarkers for healthcare,especially those relative to liver diseases.The continuous and real-time monitoring in both invasive and noninvasive manners is highly desired,while the ammonium concentrations vary largely in different body fluids.Besides,the sensing reliability based on ion-selective biosensors can be significantly interfered by potassium ions.To tackle these challenges,a flexible and biocompatible sensing patch for wireless ammonium level sensing was reported with an ultrawide linear range for universal body fluids including blood,tears,saliva,sweat and urine.The as-prepared biocompatible sensors deliver a reliable sensitivity of 58.7 mV decade-1 in the range of 1-100 mM and a desirable selectivity coefficient of 0.11 in the interference of potassium ions,attributed to the cross-calibration within the sensors array.The sensor’s biocompatibility was validated by the cell growth on the sensor surface(>80%),hemolysis rates(<5%),negligible cellular inflammatory responses and weight changes of the mice with implanted sensors.Such biocompatible sensors with ultrawide linear range and desirable selectivity open up new possibility of highly compatible biomarker analysis via different body fluids in versatile approaches.
基金supported by the Cross-research Innovation Fund of the International Graduate School at Shenzhen,Tsinghua University(JC2021002).
文摘Mueller matrix polarimetry(MMP)has been proven to be a powerful tool for characterizing the microstructural features of biological samples in biomedical research and clinical diagnostics.However,the traditional Mueller matrix(MM)imaging technique based on single exposure has a limited dynamic range,leading to poor polarization image quality for biological samples with signi-cant contrast variations.In this study,we propose a novel method to generate high dynamic range(HDR)MM images based on a multi-exposure fusion algorithm.By employing an optimal exposure selection strategy for transmission imaging and a multi-exposure weighted averaging strategy for backscattering imaging,the method expands the dynamic range while accurately preserving the polarization information of the samples.Experiments of sliced and bulk tissues demonstrate that the proposed method signi¯cantly suppresses the scattering noise and improves the quality of extracted polarization parameter images,especially in accurate distinction of di®erent pathological areas.These results highlight the potential of HDR MM imaging technology in extracting polarization information from complex biological samples with high resolution and contrast.
基金supported the Chongqing Natural Science Foundation(CSTB2023NSCQ-MSX0459&CSTB2023NSCQ-MSX0231)the Graduate Research and Innovation Foundation of Chongqing,China(CYB23048)+1 种基金the Fundamental Research Program under Grant(JCKY2022603C017)National Natural Science Foundation of China(NSFC 52175281).
文摘Electronic skin has showcased superior sensing capabilities inspired from human skin.However,most preceding studies focused on the dermis of the skin rather than the epidermis.In particular,the pseudo-porous structural domain of the epidermis increases the skin's tolerance while ensuring its susceptibility to touch.Yet,most endeavors on the porous structures failed to replicate the superior sensing performance of skin-like counterparts in terms of sensitivity and/or detection range.Stimulated by the strategy that the epidermis of the skin absorbs energy while producing ionic conduction to the nerves,this work initiatively introduced an easy-to-produce,and low-cost pressure sensor based on ionic-gel foam,and achieved a high sensitivity(2893 kPa^(-1))within a wide pressure range(up to~1 MPa),which ranked among the best cases thus far.Moreover,the factors affecting the sensor performance were explored while the sensing principles were enriched.Inspiringly,the plantar pressure measurement by harnessing the as-prepared sensor unveiled an ultra-broad detection range(100 Pa-1 MPa),thus delivering a huge application potential in the field of robot and health monitoring.
基金Supported by Finance Project of heilongjiang Province(No.HLJKD2015-11)Ministry of Natural Resources Scientific and Technological Achievements(No.20220654)National Natural Science Foundation of China(No.42261134535).
文摘To determine the geological age,petrogenesis,and tectonic setting of Mesozoic volcanic rocks in the Ningyuancun Formation in Xunke area,Lesser Hinggan Range,the zircon U-Pb geochronology,petrographic observations,and geochemical analyses of major and trace elements were conducted in this study.Zircon U-Pb dating showed that the volcanic rocks of the Ningyuancun Formation were formed in the Early Cretaceous(112.97±0.90 Ma).Major element analyses revealed that the content of SiO_(2)weighted from 74.14%to 76.54%,indicating the volcanic rocks to be high-silica and felsic.The content of Al_(2)O_(3)varies from 12.48%to 13.65%.A total alkali content of the volcanic rocks range between 8.46%and 9.56%,with Na_(2)O/K_(2)O ratios from 0.69 to 0.89.This indicated that the volcanic rocks belonged to a highly differentiated calc-alkaline series.Additionally,A/CNK values range from 0.950 to 1.015,and A/NK values vary between 0.999 and 1.127,suggesting a peraluminous characteristic.Trace element analysis showed a right-sloping“V-shaped”REE pattern,with the enrichment in light REEs and a prominent negative anomaly of Eu.The volcanic rocks are enriched in Rb,Th,U,La,and Ce,while Ba,Sr,and Ti are depleted.Rb/Sr ratio ranges from 10.01 to 12.46,Ti/Y ratio is from 51.14 to 95.72,and Ti/Zr ratio is from 5.78 to 6.41.It is suggested that the magma was derived from the partial melting of crustal rocks.This evidenced that the Early Cretaceous high-silica rhyolites were formed in an intracontinental extension in eastern Northeast China during the northwestward subduction of the Pacific Plate.The crustal extension,asthenospheric mantle upwelling and underplating of mantle-derived magmas resulted in the residual crystalline mush in Early Cretaceous mafic magma chambers to erupt.
基金financial support of the Faculty Research Grant project of the American University of Central Asia(AUCA)supported by the Ministry of Education of the Republic of Korea and the National Research Foundation of Korea(NRF-2023S1A5B5A16080131)。
文摘Geodetic observations over the past several decades identify the Tien Shan as a prominent and active intracontinental mountain belt,characterized by a meridional shortening rate of up to 20 mm/a.The region has experienced significant seismic events,particularly along its northern boundary,highlighting the recurrent seismic activity in the Kyrgyz Republic.The Issyk-Ata fault,stretching 120 km from west to east in the northern Tien Shan,bounds from the north a young,growing anticline demarcating the foothills of the Kyrgyz Range and the Chui depression.This region is susceptible to strong earthquakes,posing a significant threat to the Chui region and Bishkek,the capital city with over a million residents.The youngest fault in the area is the Issyk-Ata fault,traversing the southern part of Bishkek,where modern construction has obscured its features.This study integrates remote sensing,detailed fieldwork,and paleoseismological investigations to map and analyze surface ruptures,quantify vertical displacements,and assess seismic hazards along the Issyk-Ata fault.Using optically stimulated luminescence and radiocarbon dating,we determined ages for documented paleoseismic events,placing two ancient earthquakes in the Holocene.Magnitude estimates suggest seismic events with magnitudes ranging from 6.6 to 7.1.In the Dzhal area,geological and geomorphological analysis yielded a longterm fault-slip rate of 1.15 mm/a.The Issyk-Ata fault shows variable rupture behavior,with distinct segments demonstrating different seismic characteristics and histories of activity.This variability necessitates comprehensive seismic hazard modeling to better understand and mitigate potential risks in the region.
基金the financial support received from the National Natural Science Foundation of China(22378426,22138013)the Natural Science Foundation of Shandong Province(ZR2022MB088)the Taishan Scholar Project(ts201712020)。
文摘High-voltage dual-ion batteries(DIBs)face significant challenges,including graphite cathode degradation,cathode-electrolyte interphase(CEI)instability,and the thermodynamic instability of conventional carbonate-based electrolytes,particularly at extreme temperatures.In this study,we develop a stable electrolyte incorporating lithium difluorophosphate(LiDFP)as an additive to enhance the electrochemical performance of DIBs over a wide temperature range.LiDFP preferentially decomposes to form a rapid anion-transporting,mechanically robust CEI layer on graphite,which provides better protection by suppressing graphite's volume expansion,preventing electrolyte oxidative decomposition,and enhancing reaction kinetics.As a result,Li||graphite half cells using LiDFP electrolyte exhibit outstanding rate performance(90.8% capacity retention at 30 C)and excellent cycle stability(82.2% capacity retention after 5000 cycles)at room temperature.Moreover,graphite||graphite full cells with LiDFP electrolyte demonstrate stable discharge capacity across a temperature range of-20 to 40℃,expanding the potential applications of LiDFP.This work establishes a novel strategy for optimizing the interphase through electrolyte design,paving the way for all-climate DIBs with improved performance and stability.
基金supported by grants from the National Natural Science Foundation of China(Grant No.32271733)Guangdong Basic and Applied Basic Research Foundation(Grant No.2023A1515011045)+1 种基金Science and Technology Projects in Guangzhou(Grant No.2023A04J0121)SCNU Training Program of Innovation for Undergraduates,China。
文摘Anthropogenic climate change is altering species distributions globally.While species distributions are expected to shift to higher latitudes and elevations under global warming,empirical evidence on distribution shifts is mixed,and factors mediating the direction and magnitude of range shifts remain unclear.Using a dataset of 132new provincial records for 96 resident bird species from 2000 to 2023,we measured geographic distance,latitudinal shift,and temperature shift from each new record to the historical range for each species to test for poleward shifts.We assessed taxonomic variation in the magnitude of range shifts and used phylogenetic generalized linear mixed models to quantify relationships between species traits and the extent of range shifts.Our results revealed that new records occurred at a mean geographic distance of 420 km from historical ranges,with mean latitudinal shifts of+1.68°(poleward)and temperature shifts of-1.33℃(toward colder climates).The magnitude of geographic range shifts was strongly constrained by phylogenetic relatedness.Habitat breadth,habitat openness,and centroid latitude of historical ranges emerged as significant predictors of range shifts.Our results suggest that resident bird species'geographic ranges in China are shifting poleward,but the magnitude of these shifts is non-random across lineages.Species with broader habitat preferences and those from warmer climates are more likely to shift farther from their historical ranges and toward higher latitudes.This study emphasizes taxonomic variation in species range shifts and highlights the need for species-and site-specific conservation strategies under global warming.
基金supported by the National Natural Science Foundation of China(Grant Nos.52192633,92371201,11872293,and 92152301)the Natural Science Foundation of Shaanxi Province(Grant No.2022JC-03).
文摘The high-speed reentry vehicle operates across a broad range of speeds and spatial domains,where optimal aerodynamic shapes for different speeds are contradictory.This makes it challenging for a single-Mach optimization design to meet aerodynamic performance requirements throughout the vehicle’s flight envelope.Additionally,the strong coupling between aerodynamics and control adds complexity,as fluctuations in aerodynamic parameters due to speed variations complicate control system design.To address these challenges,this study proposes an aerodynamic/control coupling optimization design approach.This method,based on aerodynamic optimization principles,incorporates active control technology,treating aerodynamic layout and control system design as primary components during the conceptual design phase.By integrating the design and evaluation of aerodynamics and control,the approach aims to reduce design iterations and enhance overall flight performance.The comprehensive design of the rotary reentry vehicle,using this optimization strategy,effectively balances performance at supersonic and hypersonic speeds.The results show that the integrated design model meets aerodynamic and control performance requirements over a broader range of Mach numbers,preventing performance degradation due to deviations from the design Mach number,and providing a practical solution for high-speed reentry vehicle design.
文摘Large dynamic range and ultra-wideband receiving abilities are significant for many receivers. With these abilities, receivers can obtain signals with different power in ultra-wideband frequency space without information loss. However, conventional receiving scheme is hard to have large dynamic range and ultra-wideband receiving simultaneously because of the analog-to-digital converter(ADC) dynamic range and sample rate limitations. In this paper, based on the modulated sampling and unlimited sampling, a novel receiving scheme is proposed to achieve large dynamic range and ultra-wideband receiving. Focusing on the single carrier signals, the proposed scheme only uses a single self-rest ADC(SR-ADC) with low sample rate, and it achieves large dynamic range and ultra-wideband receiving simultaneously. Two receiving scenarios are considered, and they are cooperative strong signal receiving and non-cooperative strong/weak signals receiving. In the cooperative receiving scenario, an improved fast recovery method is proposed to obtain the modulated sampling output. In the non-cooperative receiving scenario, the strong and weak signals with different carrier frequencies are considered, and the signal processing method can recover and estimate each signal. Simulation results show that the proposed scheme can realize large dynamic range and ultra-wideband receiving simultaneously when the input signal-to-noise(SNR) ratio is high.
基金support from Beijing Natural Science Foundation−Xiaomi Innovation Joint Fund(Grant No.L233009)the National Natural Science Foundation of China(NSFC Grant Nos.62422409,62174152 and 62374159)from the Youth Innovation Promotion Association of Chinese Academy of Sciences(Grant No.2020115).
文摘High-performance flexible pressure sensors have garnered significant attention in fields such as wearable electronics and human-machine interfaces.However,the development of flexible pressure sensors that simultaneously achieve high sensitivity,a wide detection range,and good mechanical stability remains a challenge.In this paper,we propose a flexible piezoresistive pressure sensor based on a Ti_(3)C_(2)Tx(MXene)/polyethylene oxide(PEO)composite nanofiber membrane(CNM).The sensor,utilizing MXene(0.4 wt%)/PEO(5 wt%),exhibits high sensitivity(44.34 kPa^(−1)at 0−50 kPa,12.99 kPa^(−1)at 50−500 kPa)and can reliably monitor physiological signals and other subtle cues.Moreover,the sensor features a wide detection range(0−500 kPa),fast response and recovery time(~150/45 ms),and excellent mechanical stability(over 10000 pressure cycles at maximum load).Through an MXene/PEO sensor array,we demonstrate its applications in human physiological signal monitoring,providing a reliable way to expand the application of MXene-based flexible pressure sensors.
