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A real-time calibration method based on time-to-digital converter for accelerator timing system

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Nuclear Science and Techniques 2024年第9期35卷 127-140页

作者： Qi-hao Duan Liang Ge Yan-hao jia Jie-Yu Zhu Wei Zhang Institute of modern physics Chinese Academy of SciencesLanzhou 730000China University of Chinese Academy of Sciences Beijing 100049China

The high-intensity heavy-ion accelerator facility(HIAF)is a scientific research facility complex composed of multiple cas-cade accelerators of different types,which pose a scheduling problem for devices distributed over a certain range of 2 km,involving over a hundred *** white rabbit,a technology-enhancing Gigabit Ethernet,has shown the capability of scheduling distributed timing devices but still faces the challenge of obtaining real-time synchronization calibration param-eters with high *** study presents a calibration system based on a time-to-digital converter implemented on an ARM-based System-on-Chip(SoC).The system consists of four multi-sample delay lines,a bubble-proof encoder,an edge controller for managing data from different channels,and a highly effective calibration module that benefits from the SoC *** performance was evaluated with an average RMS precision of 5.51 ps by measuring the time intervals from 0 to 24,000 ps with 120,000 data for every *** design presented in this study refines the calibration precision of the HIAF timing *** eliminates the errors caused by manual calibration without efficiency loss and provides data support for fault *** can also be easily tailored or ported to other devices for specific applications and provides more space for developing timing systems for particle accelerators,such as white rabbits on HIAF.

关键词： HIAF White rabbit Calibration system Time-to-digital converter(TDC)

Limits on sequential sharing of nonlocal advantage of quantum coherence

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Science China(Physics,Mechanics & Astronomy) 2022年第6期65卷 26-35页

作者： Ming-Liang hu jia-Ru Wang Heng Fan School of Science Xi’an University of Posts and TelecommunicationsXi’an 710121China Institute of Physics Chinese Academy of SciencesBeijing 100190China CAS Center for Excellence in Topological Quantum Computation University of Chinese Academy of SciencesBeijing 100190China Songshan Lake Materials Laboratory Dongguan 523808China

Sequential sharing of nonlocal correlation is inherently related to its *** address the question as to how many observers can share the nonlocal advantage of quantum coherence(NAQC)in a(d×d)-dimensional state,where d is a prime or a power of a *** first analyze the trade-off between disturbance and information gain of the general d-dimensional unsharp *** in a scenario where multiple Alices perform unsharp measurements on one party of the state sequentially and independently and a single Bob measures coherence of the conditional states on the other party,we show that at most one Alice can demonstrate NAQC with *** limit holds even when considering the weak measurements with optimal pointer *** results may shed light on the interplay between nonlocal correlations and quantum measurements on high-dimensional systems and the hierarchy of different quantum correlations.

关键词： quantum coherence quantum correlation unsharp measurement

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A Comprehensive Study on the Theory of Graphene Solution-Gated Field Effect Transistor: Simulations and Experiments

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Chinese Journal of Electronics 2022年第4期31卷 652-657页

作者： hu Shihui ZHANG Jizhao WANG Zhongrong jia Yunfang College of Electron and Information Engineering Hebei University College of Electronic Information and Optical Engineering Nankai University

Graphene solution-gated field effect transistors(G-Sg FETs) have been widely developed in the field of biosensors, but deficiencies in their theories still exist. A theoretical model for G-Sg FET, including the three-terminal equivalent circuit model and the numerically calculating method, is proposed by the comprehensive analyses of the graphene-liquid interface and the FET principle. Not only the applied voltages on the electrodepairs of gate-source and drain-source, but also the nature of graphene and its derivatives are considered by analysing their influences on the Fermi level, the carriers’ concentration and mobility, which may consequently affect the output drain-source current. To verify whether it is available for G-Sg FETs based on different method prepared graphene, three kinds of graphene materials which are liquid-phase exfoliated graphene, reduced graphene oxide(r GO), and tetra(4-aminophenyl) porphyrin hybridized r GO are used as examples. The coincidences of calculated output and transfer feature curves with the measured ones are obtained to confirm its adaptivity for simulating the basic G-Sg FETs’ electric features, by modulating Fermi level and mobility. Furthermore, the model is exploited to simulate G-Sg FETs’ current responding to the biological functionalization with aptamer and the detections for circulating tumor cells, as a *** calculated current changes are compared with the experimental results, to verify the proposed G-Sg FETs’ model is also suitable for mimicking the bio-electronic responding, which may give a preview of some conceived GSg FETs’ biosensors and improve the design efficiency.

关键词： field effect transistors output drain-source Chemical sensors graphene materials graphene-liquid interface gate-source basic G-SgFETs' electric features graphene numerically calculating method Other field effect devices molecular biophysics liquid-phase exfoliated graphene biosensors Biosensors nanofabrication Electrochemistry and electrophoresis G-SgFETs' model Insulated gate field effect transistors conceived G-SgFETs' biosensors three-terminal equivalent circuit model Fermi level graphene solution-gated field effect transistor equivalent circuits G-SgFET

Fluvial sediments in the Alagxa Plateau as a dust source: iron mineralogical and geochemical evidence

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Journal of Arid Land 2019年第2期11卷 217-227页

作者： WANG Youjun jia jia LU hao LU Caichen XIA Dunsheng College of Tourism and Environmental Resource Zaozhuang University College of Geography and Environmental Sciences Zhejiang Normal University College of Earth and Environmental Sciences Lanzhou University

The Alagxa Plateau, in the margin of the northeastern Tibetan Plateau, is one of the most important dust source areas in East Asia, and the widespread sandy desert in the area is important both as a reservoir and a source of eolian silty. The northeastern margin of the Tibetan Plateau is one of the most actively-growing mountain belt on earth, and has large amounts of debris, with masses of fine grained material, which were continuously mobilized and deposited in the Alagxa Plateau by rivers, forming broad alluvial fans. It is possible that the role of fluvial sediments as a source of silty dust in the Alagxa Plateau has been underestimated. In this study, we test this hypothesis by investigating the iron mineralogical and geochemical characteristics of the fluvial sediments and the surface material of the sandy desert in the Alagxa Plateau, and comparing them with paleo-eolian dust deposits(loess) in the adjacent Chinese Loess Plateau(CLP) to investigate the possible linkages among the fluvial sediments, sandy desert and the last glacial loess of the CLP. The results show that sandy desert typically have high contents of goethite, and high ratios of goethite to hematite, similar to the fluvial sediments in the Alagxa Plateau. Based on the major element characteristics, field investigations and the results of previous studies, we found a genetic link between the silt component of the fluvial sediments and the sandy desert in the Alagxa Plateau with high value of Gt(goethite) and similarity of the Gt/(Hm(hematite)+Gt) ratio. But the silt component of the sandy desert main come from the adjacent fluvial sediments. The iron mineralogical characteristics(χ(magnetic susceptibility), χARM(anhysteretic susceptibility), SIRM(saturation isothermal remanent magnetization) and SIRM_(AF100 mT)(SIRM demagnetized at 100 mT)) of the CLP samples overlap with those of the fluvial sediments in the Alagxa Plateau, but there is a mismatch with the sandy desert samples. This suggests th

关键词： fluvial sediments silty dust sandy dust iron mineralogical and geochemical characteristic Alagxa Plateau

Ultra-low lattice thermal conductivity and promising thermoelectric figure of merit in borophene via chlorination

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Nano Research 2022年第4期15卷 3804-3811页

作者： jia He Yanxiao hu Dengfeng Li Jie Chen Center for Phononics and Thermal Energy Science China–EU Joint Lab for NanophononicsSchool of Physics Science and EngineeringTongji UniversityShanghai 200092China School of Science Chongqing University of Posts and TelecommunicationsChongqing 400065China

Monolayer boron-based materials are of current interests due to its ***,motivated by the recent experimental synthesis of semiconducting hydrogenatedαʹ-borophene and the regulation of the physical properties in layered materials by surface functionalization,we study the thermal and electronic properties ofαʹ-borophene with three different types of gas functional groups(H,F,and Cl)based on first-principles and Boltzmann transport *** is found thatαʹ-borophene can be well stabilized by fluorination and chlorination and maintain the semiconductor *** interestingly,when hydrogen is replaced with fluorine or chlorine,the lattice thermal conductivity changes from 24.3 to 5.2 or 0.73 W/(m·K)along armchair direction at 300 K,exhibiting a huge reduction by two orders of *** main reason is the decrease of both phonon group velocities and acoustic phonon relaxation time resulting from the strong phonon mode softening due to the weaken B-B bond strength and heavier atomic mass of fluorine and ***,the chlorinatedαʹ-borophene exhibits a high thermoelectric figure of merit~2 at 300 K along armchair *** study illustrates the importance of the modulation of transport properties by gas functional groups,which may promote the thermoelectric application of boron-based materials.

关键词： borophene thermal transport thermoelectric figure of merit density functional theory gas atom functionalization

NAS-HR:Neural architecture search for heart rate estimation from face videos

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Virtual Reality & Intelligent Hardware 2021年第1期3卷 33-42页

作者： hao LU hu HAN School of Artificial Intelligence University of Chinese Academy of SciencesBeijing 100049China Key Laboratory of Intelligent Information Processing Chinese Academy of Sciences(CAS)Institute of Computing TechnologyBeijing 100080China Peng Cheng Laboratory Shenzhen 518000China

Background In anticipation of its great potential application to natural human-computer interaction and health monitoring,heart-rate(HR)estimation based on remote photoplethysmography has recently attracted increasing research *** the recent deep-learning-based HR estimation methods have achieved promising performance,their computational costs remain high,particularly in mobile-computing *** We propose a neural architecture search approach for HR estimation to automatically search a lightweight network that can achieve even higher accuracy than a complex network while reducing the computational ***,we define the regions of interests based on face landmarks and then extract the raw temporal pulse signals from the R,G,and B channels in each ***,pulse-related signals are extracted using a plane-orthogonal-to-skin algorithm,which are combined with the R and G channel signals to create a spatial-temporal ***,a differentiable architecture search approach is used for the network-structure *** Compared with the state-of-the-art methods on the public-domain VIPL-HR and PURE databases,our method achieves better HR estimation performance in terms of several evaluation metrics while requiring a much lower computational cost1.

关键词： Heart-rate estimation Plane-orthogonal-to-skin STMap Differentiable architecture search

Morphological Heredity of Intermetallic Nb_(5)Si_(3)Dendrites in Hypereutectic Nb-Si Based Alloys via Non-Equilibrium Solidification

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Chinese Journal of Mechanical Engineering 2022年第5期35卷 393-400页

作者： Yueling Guo Lina jia Wenjun Lu hu Zhang School of Mechanical Engineering Beijing Institute of TechnologyBeijing 100081China Research Center of Light‑alloy Materials Frontier Institute of Science and Technology InnovationBeihang UniversityBeijing 100191China Max-Planck-Institut für Eisenforschung Max‑Planck‑Straße 140237 DüsseldorfGermany

For hypereutectic Nb-Si based alloys,primary Nb_(5)Si_(3)phases typically grow in a faceted mode during equilibrium or near-equilibrium solidification,which damages the ductility and *** address this issue,here we artificially manipulate the growth morphology of Nb_(5)Si_(3)using electron beam surface melting(EBSM)and subsequent annealing *** show that such a non-equilibrium solidification pathway enables the transition from faceted growth to non-faceted dendritic growth of Nb_(5)Si_(3),along with evident microstructure refinement,generation of metastableβ-Nb_(5)Si_(3)phases and elimination of chemical *** transformation fromβ-Nb_(5)Si_(3)toα-Nb_(5)Si_(3)and Nb solid solution(Nbss)particles is triggered by the annealing treatment at 1450°C for 5 ***,we find the annealing-mediated formation of inherited Nb_(5)Si_(3)dendrites that maintain the dendritic morphology of the original as-solidifiedβ-Nb_(5)Si_(3)*** work thus provides a feasible routine to obtain thermally stable and refinedα-Nb_(5)Si_(3)dendrites in hypereutectic Nb-Si based alloys.

关键词： Nb-Si alloy Intermetallics Nb_(5)Si_(3) Rapid solidification Dendritic growth

Modeling and Solving a Multi-Period Inventory Fulfilling and Routing Problem for Hazardous Materials

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Journal of Systems Science & Complexity 2020年第3期33卷 760-782页

作者： hu hao LI jian LI Xiang SHANG Changjing School of Economics and Management Shijiazhuang Tiedao UniversityShijiazhuang 050000China College of Information Science and Technology Beijing University of Chemical TechnologyBeijing 100029China Research Base of Beijing Modern Manufacturing Development College of Economics and ManagementBeijing University of TechnologyBeijing 100124China College of Economics and Management Beijing University of Chemical TechnologyBeijing 100029China Department of Computer Science Institute of MathematicsPhysics and Computer ScienceAberystwyth UniversityAberystwyth SY233DBUK

Any potential damage may be severe once an accident occurs involving hazardous *** is therefore important to consider the risk factor concerning hazardous material supply chains,in order to make the best inventory routing *** paper addresses the problem of hazardous material multi-period inventory routing with the assumption of a limited production capacity of a given *** goal is to achieve the manufacturer's production plan,the retailer's supply schedule and the transportation routes within a fixed *** the distribution of hazardous materials over a certain period is essentially a multiple travelling salesmen problem,the authors formulate a loadingdependent risk model for multiple-vehicle transportation and present an integer programming model to maximize the supply chain *** improved genetic algorithm considering two dimensions of chromosomes that cover the aforementioned period and supply quantity is devised to handle the integer programming *** experiments carried out demonstrate that using the proposed multiperiod joint decision-making can significantly increase the overall profit of the supply chain as compared to the use of single period decision repeatedly,while effectively reducing its risk.

关键词： Genetic algorithm integer programming model limited production capacity multi-period inventory routing problem

In situ carbon coating for enhanced chemical stability of copper nanowires

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International Journal of Minerals,Metallurgy and Materials 2022年第3期29卷 557-562页

作者： Xiaolan Tong hao hu Xingzhong Zhao Qidong Tai School of Physics and Technology Wuhan UniversityWuhan 430072China Institute of Technological Sciences Wuhan UniversityWuhan 430072China

Copper nanowires(CuNWs)are promising electrode materials,especially for used in flexible and transparent electrodes,due to their advantages of earth-abundant,low-cost,high conductivity and ***,the poor stability of CuNWs against oxidation and chemic-al corrosion seriously hinders their practical ***,we propose a facile strategy to improve the chemical stability of CuNWs by in situ coating of carbon protective layer on top of them through hydrothermal carbonization *** influential factors on the growth of carbon film including the concentration of the glucose precursor(carbon source),hydrothermal temperature,and hydrothermal time are sys-tematically *** tailoring these factors,carbon layers with thickness of 3-8 nm can be uniformly grown on CuNWs with appropriate glucose concentration around 80 mg·mL−1,hydrothermal temperature of 160-170°C,and hydrothermal time of 1-3 *** as-prepared carbon-coated CuNWs show excellent resistance against corrosion and oxidation,and are of great potential to use broadly in various optoelectronic devices.

关键词： electrode material copper nanowire in situ carbon coating stability