The naturally fermented Inner Mongolian cheese’s flavor and nutritional value make it a popular choice among customers.In this work,to create multi-functional peptides that have taste and biological activity,peptidom...The naturally fermented Inner Mongolian cheese’s flavor and nutritional value make it a popular choice among customers.In this work,to create multi-functional peptides that have taste and biological activity,peptidomics and bioinformatics were used to screen flavor peptides from Inner Mongolian cheese and further assess their antioxidant and angiotensin I-converting enzyme(ACE)inhibitory properties.According to sensory data,YH8 and IL7 had detectable bitter tastes with low thresholds of 0.03 and 0.06 mmol/L,respectively.With an umami threshold range of 0.24‒0.81 mmol/L,VQ6,FK13,HP13 and QT14 exhibited a range of flavors dominated by umami,including sweet,bitter,salty,sour and kokumi.Antioxidant activity wise,YH8,VQ6,HP13 and QT14 were well represented.The above-mentioned peptides all had some ACE inhibitory effect.The bitter peptide IL7(IC_(50)=0.08 mmol/L)had the highest level of ACE inhibitory activity,followed by YH8(IC_(50)=0.33 mmol/L).These multi-functional peptides,which have been assessed for bioactive and taste features in Inner Mongolian cheese,may have positive impacts on health and harmonize the cheese’s overall flavor.These results suggest that some flavor peptides produced in fermented foods might be with bioactivities while providing a basis for the exploration and application of multi-functional peptides.展开更多
Figure 6(a)in the paper[Chin.Phys.B 33074203(2024)]was incorrect due to editorial oversight.The correct figure is provided.This modification does not affect the result presented in the paper.
This study aims to investigate the responses of a perovskite-based direct-conversion dual-layer flat-panel detector(DL-FPD)numerically.To this end,the X-ray sensitivity,spatial resolution quantified by the modulation ...This study aims to investigate the responses of a perovskite-based direct-conversion dual-layer flat-panel detector(DL-FPD)numerically.To this end,the X-ray sensitivity,spatial resolution quantified by the modulation transfer function(MTF),and detective quantum efficiency(DQE)of the DL-FPD are evaluated numerically using a linear cascade model.In addition,both the single-crystal(SC)and polycrystalline(PC)structures of MAPbI_(3)are investigated,along with various other key parameters such as the material thickness,electric field strength,X-ray beam spectrum,and electronic readout noise.The results demonstrate that SC perovskite consistently exhibits better performance than PC perovskite owing to fewer material defects.Increasing the layer thickness may decrease the MTF,but can also enhance the sensitivity and DQE.Moreover,appropriately increasing the external electric field within the material can improve the sensitivity,MTF,and DQE.Finally,reducing the electronic readout noise can significantly enhance the DQE for low-dose imaging.This study demonstrates the potential of high-quality dual-energy X-ray imaging using direct-conversion perovskite DL-FPDs.展开更多
Traditional digitizers for signal readout of PET detectors are based on commercial analog-to-digital converters(ADC).However,the cost and power consumption of an entire electronic readout system based on digitizers fo...Traditional digitizers for signal readout of PET detectors are based on commercial analog-to-digital converters(ADC).However,the cost and power consumption of an entire electronic readout system based on digitizers for a PET scanner are high.To address this problem,a soft-core ADC based on a field-programmable gate array(FPGA)was proposed.An FPGA-based ADC(FPGA-ADC)combines low loss and high performance.To achieve good performance,the FPGA-ADC requires three calibrations:time-to-digital converter(TDC)length calibration,TDC alignment calibration,and TDC-to-ADC calibration.A prototype front-end electronics based on FPGA-ADC was built to evaluate the performance of time-of-flight positron emission tomography(TOF PET)detectors.Each PET detector consists of a LYSO crystal single-ended coupled to a silicon photomultiplier(SiPM).The experimental results show that the full-width at half-maximum(FWHM)energy resolution for 511 keV gamma photons after saturation correction of the SiPM was 12.3%.The FWHM coincidence timing resolution(CTR)of the TOF PET detector with the readout of the front-end electronic prototype is 385.2 ps.FPGA-ADCbased front-end electronics are very promising for multichannel,low-cost,highly integrated,and power-efficient readout electronic systems for radiation detector applications.展开更多
Detector and event visualization are crucial components of high-energy physics(HEP)experimental software.Virtual reality(VR)technologies and multimedia development platforms,such as Unity,offer enhanced display effect...Detector and event visualization are crucial components of high-energy physics(HEP)experimental software.Virtual reality(VR)technologies and multimedia development platforms,such as Unity,offer enhanced display effects and flexible extensibility for visualization in HEP experiments.In this study,we present a VR-based method for detector and event displays in the Jiangmen Underground Neutrino Observatory(JUNO)experiment.This method shares the same detector geometry descriptions and event data model as those in the offline software and provides the necessary data conversion interfaces.The VR methodology facilitates an immersive exploration of the virtual environment in JUNO,enabling users to investigate the detector geometry,visualize event data,and tune the detector simulation and event reconstruction algorithms.Additionally,this approach supports applications in data monitoring,physics data analysis,and public outreach initiatives.展开更多
We present the preparation and measurement of the radioactive isotope^(37)Ar,which was produced using thermal neutrons from a reactor,as a calibration source for liquid xenon time projection chambers.^(37)Ar is a low-...We present the preparation and measurement of the radioactive isotope^(37)Ar,which was produced using thermal neutrons from a reactor,as a calibration source for liquid xenon time projection chambers.^(37)Ar is a low-energy calibration source with a half-life of 35.01 days,making it suitable for calibration in the low-energy region of liquid xenon dark-matter experiments.Radioactive isotope^(37)Ar was produced by irradiating ^(36)Ar with thermal neutrons.It was subsequently measured in a gaseous xenon time projection chamber(GXe TPC)to validate its radioactivity.Our results demonstrate that^(37)Ar is an effective and viable calibration source that offers precise calibration capabilities in the low-energy domain of xenon-based detectors.展开更多
We here report a high system detection efficiency(SDE)superconducting single-photon detector(SSPD)at 2μm wavelength.The device integrates a SiO_(2)/Ta_(2)O_(5)distributed Bragg reflector(DBR)and a sandwich-structured...We here report a high system detection efficiency(SDE)superconducting single-photon detector(SSPD)at 2μm wavelength.The device integrates a SiO_(2)/Ta_(2)O_(5)distributed Bragg reflector(DBR)and a sandwich-structured double-layer NbN nanowire to enhance the optical absorption efficiency.A cold development technique is implemented to optimize the superconducting nanowires with sub-40-nm linewidths,thus enhancing the intrinsic detection efficiency(IDE).The fabricated SSPD shows an SDE exceeding 90% at 2μm wavelength.Moreover,the detector allows an operational working temperature of 2.2 K provided by a compact GM cryo-cooler.This detector delivers excellent performance at the 2μm wavelength,and its optimized structural design implies promising potential for extending detection toward longer infrared bands.It thus holds value for advancing high-sensitivity quantum technologies,mid-infrared optical communications,and dark matter detection research.展开更多
The accessibility of urban public transit directly influences residents’quality of life,travel behavior,and social equity.Its correlation with housing prices has garnered significant attention across disciplines such...The accessibility of urban public transit directly influences residents’quality of life,travel behavior,and social equity.Its correlation with housing prices has garnered significant attention across disciplines such as geography,economics,and urban planning.Although much existing research focuses on the impact of individual transportation facilities on housing prices,there is a notable gap in comprehensive analyses that assess the influence of overall urban transit accessibility on housing market dynamics.This study selected the main urban area of Hefei,China,as a case to investigate the spatial distribution of housing prices and evaluate public transit accessibility in 2022.Employing techniques such as the optimized parameter geographical detector and local spatial regression models,the study aimed to elucidate the effects and underlying mechanisms of urban transit accessibility on housing prices.The findings revealed that:1)housing prices in Hefei exhibited a clustered spatial pattern,with high prices concentrated in the city center and lower prices in peripheral areas,forming three distinct high-price hotspots with a‘belt-like’distribution;2)public transit accessibility showed a‘coreperiphery’structure,with accessibility declining in a‘circumferential’pattern around the city center.Based on the‘housing price-accessibility’dimension,four categories were identified:high price-high accessibility(37.25%),high price-low accessibility(19.07%),low price-high accessibility(21.95%),and low price-low accessibility(21.73%);3)the impact of transit accessibility on housing prices was spatially heterogeneous,with bus travel showing the strongest explanatory power(0.692),followed by automobile,subway,and bicycle travel.The interaction of these transportation modes generated a synergistic effect on housing price differentiation,with most influencing factors contributing more than 25%.These findings offer valuable insights for optimizing the spatial distribution of public transit infrastructure and improving both urban housing quality and residents’living standards.展开更多
Formamidinium lead iodide(FAPbI_(3))perovskite exhibits an impressive X-ray absorption coefficient and a large carrier mobility-lifetime product(μτ),making it as a highly promising candidate for X-ray detection appl...Formamidinium lead iodide(FAPbI_(3))perovskite exhibits an impressive X-ray absorption coefficient and a large carrier mobility-lifetime product(μτ),making it as a highly promising candidate for X-ray detection application.However,the presence of larger FA^(+)cation induces to an expansion of the Pb-I octahedral framework,which unfortunately affects both the stability and charge carrier mobility of the corresponding devices.To address this challenge,we develop a novel low-dimensional(HtrzT)PbI_(3) perovskite featuring a conjugated organic cation(1H-1,2,4-Triazole-3-thiol,HtrzT^(+))which matches well with theα-FAPbI_(3) lattices in two-dimensional plane.Benefiting from the matched lattice between(HtrzT)PbI_(3) andα-FAPbI_(3),the anchored lattice enhances the Pb-I bond strength and effectively mitigates the inherent tensile strain of theα-FAPbI_(3) crystal lattice.The X-ray detector based on(HtrzT)PbI_(3)(1.0)/FAPbI_(3) device achieves a remarkable sensitivity up to 1.83×10^(5)μC Gy_(air)^(−1) cm^(−2),along with a low detection limit of 27.6 nGy_(air) s^(−1),attributed to the release of residual stress,and the enhancement in carrier mobility-lifetime product.Furthermore,the detector exhibits outstanding stability under X-ray irradiation with tolerating doses equivalent to nearly 1.17×10^(6) chest imaging doses.展开更多
Soft X-ray detectors play a vital role in materials science,high-energy physics and medical imaging.Cs_(2)AgBiBr_(6),a lead-free double perovskite,has gained attention for its excellent optoelectronic properties,stabi...Soft X-ray detectors play a vital role in materials science,high-energy physics and medical imaging.Cs_(2)AgBiBr_(6),a lead-free double perovskite,has gained attention for its excellent optoelectronic properties,stability,and nontoxicity.However,its fast crystallization and requirement for high-temperature annealing(>250℃)often lead to inferior film quality,limiting its application in flexible devices.This study introduces an alloying strategy that significantly improves the quality of Cs_(2)AgBiBr_(6)thin films annealed at a reduced temperature of 150℃.Devices based on the alloyed thin films exhibit an ultra-low dark current of 0.32 nA·cm^(-2)and a quantum efficiency of 725%.Furthermore,the first successful integration of Cs_(2)AgBiBr_(6)with a thinfilm transistor backplane demonstrates its superior imaging performance,indicating that Cs_(2)AgBiBr_(6)is a promising material for next-generation soft X-ray sensors.展开更多
Numerous sectors,such as education,the IT sector,and corporate organizations,transitioned to virtual meetings after the COVID-19 crisis.Organizations now seek to assess participants’fatigue levels in online meetings ...Numerous sectors,such as education,the IT sector,and corporate organizations,transitioned to virtual meetings after the COVID-19 crisis.Organizations now seek to assess participants’fatigue levels in online meetings to remain competitive.Instructors cannot effectively monitor every individual in a virtual environment,which raises significant concerns about participant fatigue.Our proposed system monitors fatigue,identifying attentive and drowsy individuals throughout the online session.We leverage Dlib’s pre-trained facial landmark detector and focus on the eye landmarks only,offering a more detailed analysis for predicting eye opening and closing of the eyes,rather than focusing on the entire face.We introduce an Eye Polygon Area(EPA)formula,which computes eye activity from Dlib eye landmarks by measuring the polygonal area of the eye opening.Unlike the Eye Aspect Ratio(EAR),which relies on a single distance ratio,EPA adapts to different eye shapes(round,narrow,or wide),providing a more reliable measure for fatigue detection.The VMFD system issues a warning if a participant remains in a fatigued condition for 36 consecutive frames.The proposed technology is tested under multiple scenarios,including low-to high-lighting conditions(50-1400 lux)and both with and without glasses.This study builds an OpenCV application in Python,evaluated using the iBUG 300-W dataset,achieving 97.5%accuracy in detecting active participants.We compare VMFD with conventional methods relying on the EAR and show that the EPA technique performs significantly better.展开更多
Multi-functional Al-matrix composites with high volume fraction （55%-57%） of SiC particles are produced with the new pressureless infiltration fabrication technology. X-ray detection and microscopic observation disp...Multi-functional Al-matrix composites with high volume fraction （55%-57%） of SiC particles are produced with the new pressureless infiltration fabrication technology. X-ray detection and microscopic observation display the composites which are macroscopically homogeneous without porosity. The investigation further reveals that the SiC/Al composites possess low density （2.94 g/cm^3）, high elastic modulus （220 GPa）, prominent thermal management function as a result of low coefficient of thermal expansion （8 × 10^4 K^-1） and high thermal conductivity （235 W/（m.K）） as well as unique preventability of resonance vibration. By adopting a series of developed techniques, the multi-functional SiC/Al composites have managed to be made into near-net-shape parts. Many kinds of precision components of space-based optomechanical structures and airborne optoelectronic platform have been turned out. Of them, several typical products are being under test in practices.展开更多
Metal-organic frameworks（MOFs） are a unique class of porous crystalline materials that have shown promise for a wide range of applications. MOFs have been explored as a new type of heterogeneous catalytic materials,...Metal-organic frameworks（MOFs） are a unique class of porous crystalline materials that have shown promise for a wide range of applications. MOFs have been explored as a new type of heterogeneous catalytic materials, because of their high surface area, uniform and tunable pores, facile functionalization and incorporation of catalytic active sites. The use of multi-functional sites MOF materials as catalysts for synergistic catalysis and tandem reactions has attracted increasing attention. In this review, we aim to introduce the construction of bi-or multi-functional MOF catalysts with cooperative or cascade functions via post-synthetic modification（PSM）.展开更多
The robust magnesium surfaces with multi-functions are highly desirable,and the simple and scalable methods to construct such surfaces are urgently indispensable.Herein,we conducted a one-step spraying method to facil...The robust magnesium surfaces with multi-functions are highly desirable,and the simple and scalable methods to construct such surfaces are urgently indispensable.Herein,we conducted a one-step spraying method to facilely fabricate the robust coating with multi-functions on magnesium alloys.The as-sprayed magnesium alloys surface is superhydrophobic with a static water contact angle(WCA)of 157.0°and a roll-off angle of 6.0°.Such surface has excellent mechanical,chemical and thermal stabilities,even undergoing various physical and chemical damages,including sand impact(10 gmin^(-1),≥20 min),water impact(2 impacts s^(-1),≥180 min),abrasion(1.00 kPa,≥25 cycles),peeling(≥2.15 kPa),high temperature(200°C,≥24 h),strong acidic/salty/basic media(p H=113)and organic-solvent immersion(ethanol and n-hexane,≥24 h),demonstrating brilliant robustness.Notably,the surface displays multi-functions of corrosion protection,anti-fouling and heat insulation,which will undoubtedly promote the much wider applications of magnesium alloys.展开更多
To fulfill the demands for higher quality,efficiency and flexibility in aviation industry,a multi-functional end effector is designed to automate the drilling and riveting processes in assembling carbon fiber reinforc...To fulfill the demands for higher quality,efficiency and flexibility in aviation industry,a multi-functional end effector is designed to automate the drilling and riveting processes in assembling carbon fiber reinforced polymer(CFRP)and aluminum components for a robotic aircraft assembly system.To meet the specific functional requirements for blind rivet installation on CFRP and aluminum materials,additional modules are incorporated on the end effector aside of the basic processing modules for drilling.And all of these processing modules allow for a onestep-drilling-countersinking process,hole inspection,automatic rivet feed,rivet geometry check,sealant application,rivet insertion and installation.Besides,to guarantee the better quality of the hole drilled and joints riveted,several online detection and adjustment measures are applied to this end effector,including the reference detection and perpendicular calibration,which could effectively ensure the positioning precision and perpendicular accuracy as demanded.Finally,the test result shows that this end effector is capable of producing each hole to a positioning precision within ±0.5 mm,aperpendicular accuracy within 0.3°,a diameter tolerance of H8,and a countersink depth tolerance of±0.01 mm.Moreover,it could drill and rivet up to three joints per minute,with acceptable shearing and tensile strength.展开更多
Folate receptor(FR)overexpression occurs in a variety of cancers,including pancreatic cancer.In addition,enhanced macropinocytosis exists in K-Ras mutant pancreatic cancer.Furthermore,the occurrence of intensive desmo...Folate receptor(FR)overexpression occurs in a variety of cancers,including pancreatic cancer.In addition,enhanced macropinocytosis exists in K-Ras mutant pancreatic cancer.Furthermore,the occurrence of intensive desmoplasia causes a hypoxic microenvironment in pancreatic cancer.In this study,a novel FR-directed,macropinocytosis-enhanced,and highly cytotoxic bioconjugate folate(F)-human serum albumin(HSA)-apoprotein of lidamycin(LDP)-active enediyne(AE)derived from lidamycin was designed and prepared.F-HSA-LDP-AE consisted of four moieties:F,HSA,LDP,and AE.F-HSA-LDP presented high binding efficiency with the FR and pancreatic cancer cells.Its uptake in wild-type cells was more extensive than in K-Ras mutant-type cells.By in vivo optical imaging,F-HSA-LDP displayed prominent tumor-specific biodistribution in pancreatic cancer xenograft-bearing mice,showing clear and lasting tumor localization for 360 h.In the MTT assay,F-HSA-LDP-AE demonstrated potent cytotoxicity in three types of pancreatic cancer cell lines.It also induced apoptosis and caused G2/M cell cycle arrest.F-HSALDP-AE markedly suppressed the tumor growth of AsPc-1 pancreatic cancer xenografts in athymic mice.At well-tolerated doses of 0.5 and 1 mg/kg,(i.v.,twice),the inhibition rates were 91.2%and 94.8%,respectively(P<0.01).The results of this study indicate that the F-HSA-LDP multi-functional bioconjugate might be effective for treating K-Ras mutant pancreatic cancer.展开更多
To cope with the problem of emitter identification caused by the radar words＇ uncertainty of measured multi-function radar emitters, this paper proposes a new identification method based on stochastic syntax-directed...To cope with the problem of emitter identification caused by the radar words＇ uncertainty of measured multi-function radar emitters, this paper proposes a new identification method based on stochastic syntax-directed translation schema（SSDTS）. This method, which is deduced from the syntactic modeling of multi-function radars, considers the probabilities of radar phrases appearance in different radar modes as well as the probabilities of radar word errors occurrence in different radar phrases. It concludes that the proposed method can not only correct the defective radar words by using the stochastic translation schema, but also identify the real radar phrases and working modes of measured emitters concurrently. Furthermore, a number of simulations are presented to demonstrate the identification capability and adaptability of the SSDTS algorithm.The results show that even under the condition of the defective radar words distorted by noise,the proposed algorithm can infer the phrases, work modes and types of measured emitters correctly.展开更多
Photonic spin Hall effect(PSHE), as a novel physical effect in light–matter interaction, provides an effective metrological method for characterizing the tiny variation in refractive index(RI). In this work, we propo...Photonic spin Hall effect(PSHE), as a novel physical effect in light–matter interaction, provides an effective metrological method for characterizing the tiny variation in refractive index(RI). In this work, we propose a multi-functional PSHE sensor based on VO_(2), a material that can reveal the phase transition behavior. By applying thermal control, the mutual transformation into different phase states of VO_(2) can be realized, which contributes to the flexible switching between multiple RI sensing tasks. When VO_(2) is insulating, the ultrasensitive detection of glucose concentrations in human blood is achieved. When VO_(2) is in a mixed phase, the structure can be designed to distinguish between the normal cells and cancer cells through no-label and real-time monitoring. When VO_(2) is metallic, the proposed PSHE sensor can act as an RI indicator for gas analytes. Compared with other multi-functional sensing devices with the complex structures, our design consists of only one analyte and two VO_(2) layers, which is very simple and elegant. Therefore, the proposed VO_(2)-based PSHE sensor has outstanding advantages such as small size, high sensitivity, no-label, and real-time detection, providing a new approach for investigating tunable multi-functional sensors.展开更多
Fiber-shaped supercapacitors(FSSCs)show great potential in portable and wearable electronics due to their unique advantages of high safety,environmental friendliness,high performances,outstanding flexibility and integ...Fiber-shaped supercapacitors(FSSCs)show great potential in portable and wearable electronics due to their unique advantages of high safety,environmental friendliness,high performances,outstanding flexibility and integrability.They can directly act as the power sources or be easily integrated with other flexible devices to constitute self-powered and sustainable energy suppliers,providing excellent adaptability to irregular surfaces.This review mainly summarizes the recently reported works of FSSCs including preparation methods of various fiber electrodes,construction strategies of FSSCs and multi-functional device integrations,exploration of reaction mechanisms and strategies to improve the electrochemical performance and provision of suggestions on further designing and optimization of FSSCs.Meanwhile,it shares our perspectives on challenges and opportunities in this field,shedding light on the development of high-performance fiber-shaped supercapacitors with multifunctions.展开更多
基金supported by the central government and guides local funds for science and technology development(2022ZY0109).
文摘The naturally fermented Inner Mongolian cheese’s flavor and nutritional value make it a popular choice among customers.In this work,to create multi-functional peptides that have taste and biological activity,peptidomics and bioinformatics were used to screen flavor peptides from Inner Mongolian cheese and further assess their antioxidant and angiotensin I-converting enzyme(ACE)inhibitory properties.According to sensory data,YH8 and IL7 had detectable bitter tastes with low thresholds of 0.03 and 0.06 mmol/L,respectively.With an umami threshold range of 0.24‒0.81 mmol/L,VQ6,FK13,HP13 and QT14 exhibited a range of flavors dominated by umami,including sweet,bitter,salty,sour and kokumi.Antioxidant activity wise,YH8,VQ6,HP13 and QT14 were well represented.The above-mentioned peptides all had some ACE inhibitory effect.The bitter peptide IL7(IC_(50)=0.08 mmol/L)had the highest level of ACE inhibitory activity,followed by YH8(IC_(50)=0.33 mmol/L).These multi-functional peptides,which have been assessed for bioactive and taste features in Inner Mongolian cheese,may have positive impacts on health and harmonize the cheese’s overall flavor.These results suggest that some flavor peptides produced in fermented foods might be with bioactivities while providing a basis for the exploration and application of multi-functional peptides.
文摘Figure 6(a)in the paper[Chin.Phys.B 33074203(2024)]was incorrect due to editorial oversight.The correct figure is provided.This modification does not affect the result presented in the paper.
基金supported in part by the National Natural Science Foundation of China(Nos.12305349,12235006,12027812)Shenzhen Science and Technology Program(No.JSGGKQTD20210831174329010)Guangdong Basic and Applied Basic Research Foundation(No.2021TQ06Y108).
文摘This study aims to investigate the responses of a perovskite-based direct-conversion dual-layer flat-panel detector(DL-FPD)numerically.To this end,the X-ray sensitivity,spatial resolution quantified by the modulation transfer function(MTF),and detective quantum efficiency(DQE)of the DL-FPD are evaluated numerically using a linear cascade model.In addition,both the single-crystal(SC)and polycrystalline(PC)structures of MAPbI_(3)are investigated,along with various other key parameters such as the material thickness,electric field strength,X-ray beam spectrum,and electronic readout noise.The results demonstrate that SC perovskite consistently exhibits better performance than PC perovskite owing to fewer material defects.Increasing the layer thickness may decrease the MTF,but can also enhance the sensitivity and DQE.Moreover,appropriately increasing the external electric field within the material can improve the sensitivity,MTF,and DQE.Finally,reducing the electronic readout noise can significantly enhance the DQE for low-dose imaging.This study demonstrates the potential of high-quality dual-energy X-ray imaging using direct-conversion perovskite DL-FPDs.
基金supported by the Key R&D Program of Shandong Province(No.2023SFGC0101)Shandong Excellent Young Scientists Fund Program(Overseas)(No.2023HWYQ-047)+1 种基金the Natural Science Foundation of Shandong Province(No.ZR2022QA039)the National Natural Science Foundation of China(NSFC)(No.U2106202).
文摘Traditional digitizers for signal readout of PET detectors are based on commercial analog-to-digital converters(ADC).However,the cost and power consumption of an entire electronic readout system based on digitizers for a PET scanner are high.To address this problem,a soft-core ADC based on a field-programmable gate array(FPGA)was proposed.An FPGA-based ADC(FPGA-ADC)combines low loss and high performance.To achieve good performance,the FPGA-ADC requires three calibrations:time-to-digital converter(TDC)length calibration,TDC alignment calibration,and TDC-to-ADC calibration.A prototype front-end electronics based on FPGA-ADC was built to evaluate the performance of time-of-flight positron emission tomography(TOF PET)detectors.Each PET detector consists of a LYSO crystal single-ended coupled to a silicon photomultiplier(SiPM).The experimental results show that the full-width at half-maximum(FWHM)energy resolution for 511 keV gamma photons after saturation correction of the SiPM was 12.3%.The FWHM coincidence timing resolution(CTR)of the TOF PET detector with the readout of the front-end electronic prototype is 385.2 ps.FPGA-ADCbased front-end electronics are very promising for multichannel,low-cost,highly integrated,and power-efficient readout electronic systems for radiation detector applications.
基金supported by the National Natural Science Foundation of China(Nos.12175321,W2443004,11975021,11675275,U1932101)Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDA10010900)+2 种基金National Key Research and Development Program of China(Nos.2023YFA1606000 and 2020YFA0406400)National College Students Science and Technology Innovation ProjectUndergraduate Base Scientific Research Project of Sun Yat-sen University。
文摘Detector and event visualization are crucial components of high-energy physics(HEP)experimental software.Virtual reality(VR)technologies and multimedia development platforms,such as Unity,offer enhanced display effects and flexible extensibility for visualization in HEP experiments.In this study,we present a VR-based method for detector and event displays in the Jiangmen Underground Neutrino Observatory(JUNO)experiment.This method shares the same detector geometry descriptions and event data model as those in the offline software and provides the necessary data conversion interfaces.The VR methodology facilitates an immersive exploration of the virtual environment in JUNO,enabling users to investigate the detector geometry,visualize event data,and tune the detector simulation and event reconstruction algorithms.Additionally,this approach supports applications in data monitoring,physics data analysis,and public outreach initiatives.
基金supported by National Key R&D grant from the Ministry of Science and Technology of China(Nos.2021YFA1601600,2023YFA1606200)National Science Foundation of China(Nos.12090062,12105008)the Major State Basic Research Development Program of China.
文摘We present the preparation and measurement of the radioactive isotope^(37)Ar,which was produced using thermal neutrons from a reactor,as a calibration source for liquid xenon time projection chambers.^(37)Ar is a low-energy calibration source with a half-life of 35.01 days,making it suitable for calibration in the low-energy region of liquid xenon dark-matter experiments.Radioactive isotope^(37)Ar was produced by irradiating ^(36)Ar with thermal neutrons.It was subsequently measured in a gaseous xenon time projection chamber(GXe TPC)to validate its radioactivity.Our results demonstrate that^(37)Ar is an effective and viable calibration source that offers precise calibration capabilities in the low-energy domain of xenon-based detectors.
基金supported by the Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDA0520403)Shanghai Municipal Science and Technology Major Project(Grant No.2019SHZDZX01)+1 种基金Innovation Program for Quantum Science and Technology(Grant No.2023ZD0300100)the National Natural Science Foundation of China(Grant Nos.U24A20320 and 62401554)。
文摘We here report a high system detection efficiency(SDE)superconducting single-photon detector(SSPD)at 2μm wavelength.The device integrates a SiO_(2)/Ta_(2)O_(5)distributed Bragg reflector(DBR)and a sandwich-structured double-layer NbN nanowire to enhance the optical absorption efficiency.A cold development technique is implemented to optimize the superconducting nanowires with sub-40-nm linewidths,thus enhancing the intrinsic detection efficiency(IDE).The fabricated SSPD shows an SDE exceeding 90% at 2μm wavelength.Moreover,the detector allows an operational working temperature of 2.2 K provided by a compact GM cryo-cooler.This detector delivers excellent performance at the 2μm wavelength,and its optimized structural design implies promising potential for extending detection toward longer infrared bands.It thus holds value for advancing high-sensitivity quantum technologies,mid-infrared optical communications,and dark matter detection research.
基金Under the auspices of the National Natural Science Foundation of China(No.42271224,41901193)Ministry of Edu cation Humanities and Social Sciences Research Planning Fund Project of China(No.24YJAZH190)+1 种基金Anhui Province Excellent Youth Research Project in Universities(No.2022AH030019)Anhui Social Sciences Innovation Development Research Project(No.2024CXQ503)。
文摘The accessibility of urban public transit directly influences residents’quality of life,travel behavior,and social equity.Its correlation with housing prices has garnered significant attention across disciplines such as geography,economics,and urban planning.Although much existing research focuses on the impact of individual transportation facilities on housing prices,there is a notable gap in comprehensive analyses that assess the influence of overall urban transit accessibility on housing market dynamics.This study selected the main urban area of Hefei,China,as a case to investigate the spatial distribution of housing prices and evaluate public transit accessibility in 2022.Employing techniques such as the optimized parameter geographical detector and local spatial regression models,the study aimed to elucidate the effects and underlying mechanisms of urban transit accessibility on housing prices.The findings revealed that:1)housing prices in Hefei exhibited a clustered spatial pattern,with high prices concentrated in the city center and lower prices in peripheral areas,forming three distinct high-price hotspots with a‘belt-like’distribution;2)public transit accessibility showed a‘coreperiphery’structure,with accessibility declining in a‘circumferential’pattern around the city center.Based on the‘housing price-accessibility’dimension,four categories were identified:high price-high accessibility(37.25%),high price-low accessibility(19.07%),low price-high accessibility(21.95%),and low price-low accessibility(21.73%);3)the impact of transit accessibility on housing prices was spatially heterogeneous,with bus travel showing the strongest explanatory power(0.692),followed by automobile,subway,and bicycle travel.The interaction of these transportation modes generated a synergistic effect on housing price differentiation,with most influencing factors contributing more than 25%.These findings offer valuable insights for optimizing the spatial distribution of public transit infrastructure and improving both urban housing quality and residents’living standards.
基金supports from the National Natural Science Foundation of China(22375220,U2001214,22471302)the Guangdong Basic and Applied Basic Research Foundation(2024B1515020101)Open Project Fund from State Key Laboratory of Optoelectronic Materials and Technologies(OEMT-2024-KF-08).
文摘Formamidinium lead iodide(FAPbI_(3))perovskite exhibits an impressive X-ray absorption coefficient and a large carrier mobility-lifetime product(μτ),making it as a highly promising candidate for X-ray detection application.However,the presence of larger FA^(+)cation induces to an expansion of the Pb-I octahedral framework,which unfortunately affects both the stability and charge carrier mobility of the corresponding devices.To address this challenge,we develop a novel low-dimensional(HtrzT)PbI_(3) perovskite featuring a conjugated organic cation(1H-1,2,4-Triazole-3-thiol,HtrzT^(+))which matches well with theα-FAPbI_(3) lattices in two-dimensional plane.Benefiting from the matched lattice between(HtrzT)PbI_(3) andα-FAPbI_(3),the anchored lattice enhances the Pb-I bond strength and effectively mitigates the inherent tensile strain of theα-FAPbI_(3) crystal lattice.The X-ray detector based on(HtrzT)PbI_(3)(1.0)/FAPbI_(3) device achieves a remarkable sensitivity up to 1.83×10^(5)μC Gy_(air)^(−1) cm^(−2),along with a low detection limit of 27.6 nGy_(air) s^(−1),attributed to the release of residual stress,and the enhancement in carrier mobility-lifetime product.Furthermore,the detector exhibits outstanding stability under X-ray irradiation with tolerating doses equivalent to nearly 1.17×10^(6) chest imaging doses.
基金supported by the NSFC under Grant No.62474169the National Key Research and Development Program of China under Grant No.2024YFB3212200the funding from USTC under Grant Nos.WK2100000025,KY2190000003,and KY2190000006。
文摘Soft X-ray detectors play a vital role in materials science,high-energy physics and medical imaging.Cs_(2)AgBiBr_(6),a lead-free double perovskite,has gained attention for its excellent optoelectronic properties,stability,and nontoxicity.However,its fast crystallization and requirement for high-temperature annealing(>250℃)often lead to inferior film quality,limiting its application in flexible devices.This study introduces an alloying strategy that significantly improves the quality of Cs_(2)AgBiBr_(6)thin films annealed at a reduced temperature of 150℃.Devices based on the alloyed thin films exhibit an ultra-low dark current of 0.32 nA·cm^(-2)and a quantum efficiency of 725%.Furthermore,the first successful integration of Cs_(2)AgBiBr_(6)with a thinfilm transistor backplane demonstrates its superior imaging performance,indicating that Cs_(2)AgBiBr_(6)is a promising material for next-generation soft X-ray sensors.
文摘Numerous sectors,such as education,the IT sector,and corporate organizations,transitioned to virtual meetings after the COVID-19 crisis.Organizations now seek to assess participants’fatigue levels in online meetings to remain competitive.Instructors cannot effectively monitor every individual in a virtual environment,which raises significant concerns about participant fatigue.Our proposed system monitors fatigue,identifying attentive and drowsy individuals throughout the online session.We leverage Dlib’s pre-trained facial landmark detector and focus on the eye landmarks only,offering a more detailed analysis for predicting eye opening and closing of the eyes,rather than focusing on the entire face.We introduce an Eye Polygon Area(EPA)formula,which computes eye activity from Dlib eye landmarks by measuring the polygonal area of the eye opening.Unlike the Eye Aspect Ratio(EAR),which relies on a single distance ratio,EPA adapts to different eye shapes(round,narrow,or wide),providing a more reliable measure for fatigue detection.The VMFD system issues a warning if a participant remains in a fatigued condition for 36 consecutive frames.The proposed technology is tested under multiple scenarios,including low-to high-lighting conditions(50-1400 lux)and both with and without glasses.This study builds an OpenCV application in Python,evaluated using the iBUG 300-W dataset,achieving 97.5%accuracy in detecting active participants.We compare VMFD with conventional methods relying on the EAR and show that the EPA technique performs significantly better.
基金Foundation items： High-technology Research and Development Programme of China （2007AA03Z544） Aeronautical Science Foundation of China （20075221001）
文摘Multi-functional Al-matrix composites with high volume fraction （55%-57%） of SiC particles are produced with the new pressureless infiltration fabrication technology. X-ray detection and microscopic observation display the composites which are macroscopically homogeneous without porosity. The investigation further reveals that the SiC/Al composites possess low density （2.94 g/cm^3）, high elastic modulus （220 GPa）, prominent thermal management function as a result of low coefficient of thermal expansion （8 × 10^4 K^-1） and high thermal conductivity （235 W/（m.K）） as well as unique preventability of resonance vibration. By adopting a series of developed techniques, the multi-functional SiC/Al composites have managed to be made into near-net-shape parts. Many kinds of precision components of space-based optomechanical structures and airborne optoelectronic platform have been turned out. Of them, several typical products are being under test in practices.
基金supported by the National Natural Science Foundation of China (Nos. 21371069 and 21621001)
文摘Metal-organic frameworks（MOFs） are a unique class of porous crystalline materials that have shown promise for a wide range of applications. MOFs have been explored as a new type of heterogeneous catalytic materials, because of their high surface area, uniform and tunable pores, facile functionalization and incorporation of catalytic active sites. The use of multi-functional sites MOF materials as catalysts for synergistic catalysis and tandem reactions has attracted increasing attention. In this review, we aim to introduce the construction of bi-or multi-functional MOF catalysts with cooperative or cascade functions via post-synthetic modification（PSM）.
基金supported by the National Natural Science Foundation of China(21773019,21972012)the Graduate Research and Innovation Foundation of Chongqing(CYB18044)the sharing fund of Chongqing University s Large-scale Equipment
文摘The robust magnesium surfaces with multi-functions are highly desirable,and the simple and scalable methods to construct such surfaces are urgently indispensable.Herein,we conducted a one-step spraying method to facilely fabricate the robust coating with multi-functions on magnesium alloys.The as-sprayed magnesium alloys surface is superhydrophobic with a static water contact angle(WCA)of 157.0°and a roll-off angle of 6.0°.Such surface has excellent mechanical,chemical and thermal stabilities,even undergoing various physical and chemical damages,including sand impact(10 gmin^(-1),≥20 min),water impact(2 impacts s^(-1),≥180 min),abrasion(1.00 kPa,≥25 cycles),peeling(≥2.15 kPa),high temperature(200°C,≥24 h),strong acidic/salty/basic media(p H=113)and organic-solvent immersion(ethanol and n-hexane,≥24 h),demonstrating brilliant robustness.Notably,the surface displays multi-functions of corrosion protection,anti-fouling and heat insulation,which will undoubtedly promote the much wider applications of magnesium alloys.
基金supported by the National Natural Science Foundations of China(Nos.5157051626,51475225)
文摘To fulfill the demands for higher quality,efficiency and flexibility in aviation industry,a multi-functional end effector is designed to automate the drilling and riveting processes in assembling carbon fiber reinforced polymer(CFRP)and aluminum components for a robotic aircraft assembly system.To meet the specific functional requirements for blind rivet installation on CFRP and aluminum materials,additional modules are incorporated on the end effector aside of the basic processing modules for drilling.And all of these processing modules allow for a onestep-drilling-countersinking process,hole inspection,automatic rivet feed,rivet geometry check,sealant application,rivet insertion and installation.Besides,to guarantee the better quality of the hole drilled and joints riveted,several online detection and adjustment measures are applied to this end effector,including the reference detection and perpendicular calibration,which could effectively ensure the positioning precision and perpendicular accuracy as demanded.Finally,the test result shows that this end effector is capable of producing each hole to a positioning precision within ±0.5 mm,aperpendicular accuracy within 0.3°,a diameter tolerance of H8,and a countersink depth tolerance of±0.01 mm.Moreover,it could drill and rivet up to three joints per minute,with acceptable shearing and tensile strength.
基金supported by grants from CAMS Innovation Fund for Medical Sciences(Grant No.:2021-I2M-1-026)Scientific Research Project of Tianjin Education Commission(Grant No.:2020KJ140)Tianjin Health Research Project(Grant No.:KJ20017)。
文摘Folate receptor(FR)overexpression occurs in a variety of cancers,including pancreatic cancer.In addition,enhanced macropinocytosis exists in K-Ras mutant pancreatic cancer.Furthermore,the occurrence of intensive desmoplasia causes a hypoxic microenvironment in pancreatic cancer.In this study,a novel FR-directed,macropinocytosis-enhanced,and highly cytotoxic bioconjugate folate(F)-human serum albumin(HSA)-apoprotein of lidamycin(LDP)-active enediyne(AE)derived from lidamycin was designed and prepared.F-HSA-LDP-AE consisted of four moieties:F,HSA,LDP,and AE.F-HSA-LDP presented high binding efficiency with the FR and pancreatic cancer cells.Its uptake in wild-type cells was more extensive than in K-Ras mutant-type cells.By in vivo optical imaging,F-HSA-LDP displayed prominent tumor-specific biodistribution in pancreatic cancer xenograft-bearing mice,showing clear and lasting tumor localization for 360 h.In the MTT assay,F-HSA-LDP-AE demonstrated potent cytotoxicity in three types of pancreatic cancer cell lines.It also induced apoptosis and caused G2/M cell cycle arrest.F-HSALDP-AE markedly suppressed the tumor growth of AsPc-1 pancreatic cancer xenografts in athymic mice.At well-tolerated doses of 0.5 and 1 mg/kg,(i.v.,twice),the inhibition rates were 91.2%and 94.8%,respectively(P<0.01).The results of this study indicate that the F-HSA-LDP multi-functional bioconjugate might be effective for treating K-Ras mutant pancreatic cancer.
基金supported by the National Natural Science Foundation of China (No. 61002026)
文摘To cope with the problem of emitter identification caused by the radar words＇ uncertainty of measured multi-function radar emitters, this paper proposes a new identification method based on stochastic syntax-directed translation schema（SSDTS）. This method, which is deduced from the syntactic modeling of multi-function radars, considers the probabilities of radar phrases appearance in different radar modes as well as the probabilities of radar word errors occurrence in different radar phrases. It concludes that the proposed method can not only correct the defective radar words by using the stochastic translation schema, but also identify the real radar phrases and working modes of measured emitters concurrently. Furthermore, a number of simulations are presented to demonstrate the identification capability and adaptability of the SSDTS algorithm.The results show that even under the condition of the defective radar words distorted by noise,the proposed algorithm can infer the phrases, work modes and types of measured emitters correctly.
基金Project supported by the National Natural Science Foundation of China(Grant No.NSFC 12175107)the Natural Science Foundation of Nanjing Vocational University of Industry Technology,China(Grant No.YK22-02-08)+3 种基金the Qing Lan Project of Jiangsu Province,Chinathe Postgraduate Research&Practice Innovation Program of Jiangsu Province,China(Grant No.KYCX23_0964)the Natural Science Foundation of Jiangsu Province,China(Grant No.BK20230347)the Fund from the Research Center of Industrial Perception and Intelligent Manufacturing Equipment Engineering of Jiangsu Province,China(Grant No.ZK21-05-09)。
文摘Photonic spin Hall effect(PSHE), as a novel physical effect in light–matter interaction, provides an effective metrological method for characterizing the tiny variation in refractive index(RI). In this work, we propose a multi-functional PSHE sensor based on VO_(2), a material that can reveal the phase transition behavior. By applying thermal control, the mutual transformation into different phase states of VO_(2) can be realized, which contributes to the flexible switching between multiple RI sensing tasks. When VO_(2) is insulating, the ultrasensitive detection of glucose concentrations in human blood is achieved. When VO_(2) is in a mixed phase, the structure can be designed to distinguish between the normal cells and cancer cells through no-label and real-time monitoring. When VO_(2) is metallic, the proposed PSHE sensor can act as an RI indicator for gas analytes. Compared with other multi-functional sensing devices with the complex structures, our design consists of only one analyte and two VO_(2) layers, which is very simple and elegant. Therefore, the proposed VO_(2)-based PSHE sensor has outstanding advantages such as small size, high sensitivity, no-label, and real-time detection, providing a new approach for investigating tunable multi-functional sensors.
基金upported by the National Natural Science Foundation of China(No.21875226)the Science Fund for Distinguished Young Scholars of Sichuan Province(No.2017JQ0036)the Chengdu Rongpiao Talent plan,the Sichuan'Ten-thousand Talents Program",the"QianYingBaiTuan"Plan of China Mianyang Science City,the Science Foundation of Institute of Chemical Materials(No.O11100301)the"Global Experts Recruitment"program.
文摘Fiber-shaped supercapacitors(FSSCs)show great potential in portable and wearable electronics due to their unique advantages of high safety,environmental friendliness,high performances,outstanding flexibility and integrability.They can directly act as the power sources or be easily integrated with other flexible devices to constitute self-powered and sustainable energy suppliers,providing excellent adaptability to irregular surfaces.This review mainly summarizes the recently reported works of FSSCs including preparation methods of various fiber electrodes,construction strategies of FSSCs and multi-functional device integrations,exploration of reaction mechanisms and strategies to improve the electrochemical performance and provision of suggestions on further designing and optimization of FSSCs.Meanwhile,it shares our perspectives on challenges and opportunities in this field,shedding light on the development of high-performance fiber-shaped supercapacitors with multifunctions.
