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A direct measurement method of quantum relaxation time

National science Review 2021年第4期8卷 91-99页

作者： Peng Zhang Haoqi Tang Chuanchuan Gu Hong Wang Guangfu Luo Yalin Lu X.-D.Xiang Department of Materials Science and Engineering & Department of Physics Southern University of Science and Technology Synergetic Innovation Center of Quantum Information and Quantum Physics & Hefei National Laboratory for Physical Sciences at Microscale University of Science and Technology of China Materials Genome Initiative Center and School of Materials Science and Engineering Shanghai Jiao Tong University State Key Laboratory of Green Building Materials China Building Materials Academy Guangdong Provincial Key Laboratory of Computational Science and Material Design Southern University of Science and Technology

The quantum relaxation time of electrons in condensed matters is an important physical property, but its direct measurement has been elusive for a century. Here, we report a breakthrough that allows direct determination of quantum relaxation time at zero and non-zero frequencies using optical *** dielectric loss function, we connect bound electron effects to the physical parameters of plasma resonance and find an extra term of quantum relaxation time from inelastic scattering between bound electrons and conduction electrons at non-zero frequencies. We demonstrate here that the frequency-dependent inelastic polarization effect of bound electrons is the dominant contribution to quantum relaxation time of conduction electrons at optical frequencies, and the elastic polarization effect of bound electrons also dramatically changes the plasma resonance frequency through effective screening to charge carriers.

关键词： quantum relaxation time plasma resonance dielectric loss function

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Vertically aligned cellulose nanofiber/carbon nanotube aerogel-infused epoxy nanocomposites for highly efficient solar-thermal-electric conversion

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材料科学技术（英文版） 2025年第11期214卷 313-321页

作者： Jiali Yan Yu Sun Tao Jia Bin Tao Min Hong Pingan Song Miaojun Xu Key Laboratory of Bio-based Material Science and Technology of Ministry of Education Northeast Forestry UniversityHarbin 150040China Heilongjiang Key Laboratory of Molecular Design and Preparation of Flame Retarded Materials College of ChemistryChemical Engineering and Resource UtilizationNortheast Forestry UniversityHarbin 150040China Heilongjiang Ecological Engineering College Harbin 150025China Heilongjiang Key Laboratory of Molecular Design and Preparation of Flame Retarded Materials College of ChemistryChemical Engineering and Resource UtilizationNortheast Forestry UniversityHarbin 150040China Centre for Future Materials University of Southern QueenslandSpringfield CentralQLD 4300Australia Centre for Future Materials University of Southern QueenslandSpringfield CentralQLD 4300Australia School of Agriculture and Environmental Science University of Southern QueenslandSpringfield 4300Australia

Solar-driven thermo-electric generation(STEG)emerges as a promising solution to mitigate the global en-ergy ***,the practical application of conventional photothermal materials equipped with STEG is limited due to low solar thermal conversion ***,we fabricated an epoxy resin(EP)nanocomposite,EP/CCA80,with excellent photo-thermal-electric conversion properties by embedding a vertically aligned aerogel consisting of cellulose nanofibers(CNF)and carboxylated multi-walled carbon nanotubes(CMWCNTs)into a transparent EP ***/CCA80 composites possessed a broad light ab-sorption range from 200 nm to 2500 nm and excellent photothermal *** illumination of 1.0 kW m-2,EP/CCA80 achieved a notable stable temperature of 93.2 ℃ and a photothermal conversion efficiency of up to 54.35％with only 0.65 wt％CMWCNTs ***,coupled with thermo-electric(TE)devices,the EP/CCA80 composite facilitated a significant temperature difference and voltage output of up to 25.3 ℃ and 160.29 mV(1.0 kW m-2),respectively,which could power a small fan to rotate at a speed of 193 *** materials are poised to offer viable solutions for enhancing energy accessibility in remote regions,thereby contributing to the reduction of energy shortages and environ-mental degradation.

关键词： Solar-thermal-electric conversion Photothermal performance Epoxy resin Cellulose nanofibers Carboxylated multi-walled carbon nanotubes

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Accurate Monocular Pose Measurement for Aircraft Transportation Monitoring

Accurate Monocular Pose Measurement for Aircraft Transportat...

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2024 IEEE International Conference on Unmanned Systems, ICUS 2024

作者： Sun, Xiaoliang Zhang, Zhuo Bi, Daoming Guo, Liangchao Wang, Qiufu Chen, Lin College of Aerospace Science and Engineering National University of Defense Technology Changsha China Hunan Provincial Key Laboratory of Image Measurement and Vision Navigation Changsha China AVIC Shenyang Aircraft Design & Research Institute Shenyang China

ISBN: (纸本)9798350384185

Comprehensive statue monitoring is of great significance for aircraft safety and efficient transportation. This paper proposes an accurate and efficient monocular pose measurement method for aircraft transportation monitoring. The proposed method firstly models the aircraft using a sparse keypoint set for simplicity. Then, based on the simple representation, a trained neural network model is adapted to detect the keypoints from the input monocular image to build 2D-3D correspondences for pose measurement. Coarse pose estimation is got by solving a Perspective-n-Point problem based on the 2D-3D correspondences. For accurate pose measurement, this paper uses the contour feature to refine the pose measurement. The refinement is achieved via gradient orientation based template matching. Experimental results indicate that the proposed method achieves accurate and efficient monocular pose measurement for aircraft transportation monitoring. © 2024 IEEE.

关键词： Template matching

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Comparison of dominant frequency attenuation of blasting vibration for different charge structures

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Journal of Rock Mechanics and Geotechnical Engineering 2022年第2期14卷 448-459页

作者： Pengchang Sun Wenbo Lu Junru Zhou Xincheng Huang Ming Chen Qi Li State Key Laboratory of Water Resources and Hydropower Engineering Science Wuhan UniversityWuhan430072China School of Resource and Environmental Engineering Wuhan University of Science and TechnologyWuhan430081China Changjiang Institute of Survey PlanningDesign and ResearchWuhan430010China

Dominant frequency attenuation is a significant concern for frequency-based criteria of blasting vibration *** is necessary to develop a concise and practical prediction equation describing dominant frequency *** this paper,a prediction equation of dominant frequency that accounts for primary parameters influencing the dominant frequency was proposed based on theoretical and dimensional *** blasting experiments were carried out in the Chiwan parking lot for collecting blasting vibration data used to conduct regression analysis of the proposed prediction *** fitting equations were further adopted to compare the reliability of three different types of dominant frequencies in the proposed equation and to explore the effects of different charge structures on the dominant frequency *** apparent frequency proved to be more reliable to express the attenuation law of the dominant *** reliability and superiority of the proposed equation employing the apparent frequency were verified by comparison with the other five prediction *** smaller blasthole diameter or decoupling ratio leads to the higher initial value and corresponding faster attenuation of the dominant *** blasthole diameter has a greater influence on the dominant frequency attenuation than the decoupling ratio *** the charge structures applied in the experiments,the charge structure with decoupling ratio of 1.5 and blasthole diameter of 48 mm results in the greatest initial value and corresponding fastest attenuation of the dominant frequency.

关键词： Dominant frequency Blasting vibration Attenuation law Prediction equation Charge structures

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Oxidation State as a Descriptor in Oxygen Reduction Electrocatalysis

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CCS Chemistry 2022年第11期4卷 3587-3598页

作者： Ning Qin Sicen Yu Zongwei Ji Yanfang Wang Yingzhi Li Shuai Gu Qingmeng Gan Zhenyu Wang Zhiqiang Li Guangfu Luo Kaili Zhang Zhouguang Lu Department of Materials Science and Engineering Shenzhen Key Laboratory of Interfacial Science and Engineering of MaterialsSouthern University of Science and TechnologyShenzhen 518055 Department of Mechanical Engineering City University of Hong KongKowloonHong Kong 999077 Guangdong Provincial Key Laboratory of Computational Science and Material Design Southern University of Science and TechnologyShenzhen 518055

Electrocatalysts for the oxygen reduction reaction(ORR)are critically important in the development of fuel cells and metal-air *** research interests have been devoted to improving the electrocatalytic performance by tuning the morphology and defect-active ***,we demonstrate that the oxidation state can also serve as an effective strategy for designingORR *** of silver with gradient chemical valence from zero valence to trivalence were successfully *** oxidation states were evaluated by cryo-X-ray photoelectron spectroscopy,X-ray absorptionfinestructure,and electron paramagnetic resonance *** the first time,our results demonstrated that the electrocatalytic activities of silver species can be improved by increasing their valence,conforming the orderofAgdesigning efficient ORR electrocatalysts.

关键词： silver oxides high valence oxygen reduction oxidation state electrocatalysis

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Physical Layer Security for UAV Communications:A Comprehensive Survey

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China Communications 2022年第9期19卷 77-115页

作者： Jue Wang Xuanxuan Wang Ruifeng Gao Chengleyang Lei Wei Feng Ning Ge Shi Jin Tony Q.S.Quek School of Information Science and Technology Nantong UniversityNantong 226109China Department of Electronic Engineering Tsinghua UniversityBeijing 100084China China Academy of Electronics and Information Technology Beijing 100041China School of Transportation and Civil Engineering Nantong UniversityNantong 226109China National Mobile Communications Research Laboratory Southeast UniversityNanjing 210096China Information Systems Technology and Design Pillar Singapore University of Technology and DesignSingapore 487372Singapore Nantong Research Institute for Advanced Communication Technologies Nantong 226109China

Due to its high mobility and flexible deployment,unmanned aerial vehicle(UAV)is drawing unprecedented interest in both military and civil applications to enable agile and ubiquitous *** operating in an open environment,UAV communications benefit from dominant line-of-sight links;however,this on the other hand renders the communications more vulnerable to malicious ***,physical layer security(PLS)has been introduced to UAV systems as an important complement to the conventional cryptography-based *** this paper,a comprehensive survey on the current achievements of UAV-PLS is *** first introduce the basic concepts including typical static/-mobile UAV deployment scenarios,the unique air-toground channel and aerial nodes distribution models,as well as various roles that a UAV may act when PLS is ***,we start by reviewing the secrecy performance analysis and enhancing techniques for statically deployed UAV systems,and extend the discussion to the more general scenario where the UAVs’mobility is further *** both cases,respectively,we summarize the commonly adopted methodologies,then describe important works in the litera ture in ***,potential research directions and challenges are discussed to provide an outlook for future works in the area of UAV-PLS.

关键词： physical layer security UAV communications static/mobile UAV deployment air-to-ground channel trajectory optimization

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Efficient photoreduction strategy for uranium immobilization based on graphite carbon nitride/activated carbon nanocomposites

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Chinese Chemical Letters 2022年第7期33卷 3581-3584页

作者： Shuyang Li Zhiwei Niu Duoqiang Pan Zhenpeng Cui Hewen Shang Jie Lian Wangsuo Wu Frontiers Science Center for Rare Isotopes Lanzhou UniversityLanzhou 730000China School of Nuclear Science and Technology Lanzhou UniversityLanzhou 730000China Key Laboratory of Special Function Materials and Structure Design Ministry of EducationLanzhou 730000China

Uranium removal from aqueous solutions using environmentally friendly photocatalytic technology is a novel approach for resource ***,carbon nitride/activated carbon composite materials(CN/AC)were investigated for U(Ⅵ)reduction under visible *** exceptional boost in photocatalytic activity was observed for CN/AC composites(up to 70 times over the conventional bulk g-C_(3)N_(4)).The strong interactive conjugatedπ-bond structure between g-C_(3)N_(4) and AC accelerated the migration of carriers and then prolonged the electron ***/AC composites exhibited excellent compatibility with different water substrates and were resilience to a wide range of p H changes and abundant competitive anions/*** experiments and electron microscopy characterization indicated that U(VI)was reduced by photogenerated electrons and deposited on the edge of CN/AC *** low-cost,high-performance carbon-based composite material proposed in this work is a potential candidate for the efficient treatment of radioactive wastewater.

关键词： Uranium removal Photoreduction Graphitic carbon nitride Activated carbon Composite material

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Effects of soil amendment and foliar selenium applications on cadmium immobilization in soil and accumulation in wheat

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Pedosphere 2024年第6期34卷 1123-1135页

作者： Qiqi LIU Tianyi WU Qiugang WU Chen ZHANG Dafu WU Lihao ZHANG Jing ZHOU Huan ZHANG Jun ZHOU School of Resources and Environment Henan Institute of Science and TechnologyXinxiang 453003China Jiangsu Design Institute of Geology for Mineral Resources Xuzhou 221006China Ky Laboratory of Soil Environment and Pollution Remediation Institute of Soil ScienceChinese Academy of SciencesNanjing 210008China University of Chinese Academy of Sciences Beijing 100049China National Engineering and Technology Research Center for Red Soil Improvement Red Soil Ecological Experiment StationChinese Academy of SciencesYingtan 335211China Sino-Japan Friendship Center for Environmental Protection Beijing 100029China

Wheat cadmium(Cd)contamination is one of the environmental and agricultural concerns ***,the effects of applications of foliar selenium(Se)and soil amendments(lime,mixture of biofuel ash and sodium sulfide(DSO),and mixture of iron mine tailing and alkali lignin(MX))on soil Cd fractions and wheat Cd accumulation were studied using laboratory incubation,greenhouse pot,and field plot *** the laboratory incubation experiment,lime and MX applications significantly increased soil pH,DSO application significantly decreased soil p H,while all the three amendments significantly reduced soil bioavailable Cd fractions by 16%–21%compared to the control without any *** Se application significantly increased the growth and yield of the high-Cd-accumulating cultivar(Puxing5).In the greenhouse experiment,lime and MX applications considerably decreased grain Cd concentration by 55%and 47%,respectively,for Puxing5 and by 24%and 26%,respectively,for the low-Cd-accumulating cultivar(Zhoumai30).In the field experiment,grain Cd concentration was significantly reduced by 68%and 72%by lime and MX applications,respectively,for *** of DSO also significantly reduced grain Cd concentration by 58%for Puxing5 and 25%for Zhoumai30 in the greenhouse experiment,but increased grain Cd concentration by 22%for Puxing5 in the field *** results implicate that laboratory incubation and greenhouse experiment results are necessary to be verified in field,and foliar Se application is recommended when considering both financial costs and production safety.

关键词： bioavailable Cd fraction cadmium contamination field plot experiment grain Cd concentration laboratory incubation pot experiment

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Exploration on learning molecular docking with deep learning models

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Quantitative Biology 2023年第3期11卷 320-331页

作者： Qin Xie Wei Ma Jianhang Zhang Shiliang Li Xiaobing Deng Youjun Xu Weilin Zhang Infinite Intelligence Pharma Beijing 100083China Shanghai Key Laboratory of New Drug Design State Key Laboratory of Bioreactor EngineeringSchool of PharmacyEast China University of Science and TechnologyShanghai 200237China College of Chemistry and Molecular Engineering Peking UniversityBeijing 100871China

Background:Molecular docking-based virtual screening(VS)aims to choose ligands with potential pharmacological activities from millions or even billions of *** process could significantly cut down the number of compounds that need to be experimentally ***,during the docking calculation,many molecules have low affinity for a particular protein target,which waste a lot of computational ***:We implemented a fast and practical molecular screening approach called DL-DockVS(deep learning dock virtual screening)by using deep learning models(regression and classification models)to learn the outcomes of pipelined docking programs ***:In this study,we showed that this approach could successfully weed out compounds with poor docking scores while keeping compounds with potentially high docking scores against 10 DUD-E protein targets.A self-built dataset of about 1.9 million molecules was used to further verify DL-DockVS,yielding good results in terms of recall rate,active compounds enrichment factor and runtime ***:We comprehensively evaluate the practicality and effectiveness of DL-DockVS against 10 protein *** to the improvements of runtime and maintained success rate,it would be a useful and promising approach to screen ultra-large compound libraries in the age of big *** is also very convenient for researchers to make a well-trained model of one specific target for predicting other chemical libraries and high docking-score molecules without docking computation again.

关键词： molecular docking ultra-large virtual screening deep learning

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design,hydrodynamic analysis,and testing of a bioinspired controllable wing mechanism with multi-locomotion modes for hybrid-driven underwater gliders

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science China(Technological sciences) 2021年第12期64卷 2688-2708页

作者： SUN TongShuai WANG YanHui YANG ShaoQiong WANG Cheng ZHANG LianHong Key Laboratory of Mechanism Theory and Equipment Design of Ministry of Education Tianjin UniversityTianjin 300072China Qingdao Pilot National Laboratory for Marine Science and Technology(QNLM) Qingdao 266237China

Hybrid-driven technology,which can improve the sailing performance of underwater gliders(UGs),has been successfully used in ocean ***,a hybrid-driven UG(HUG)with an added tail propeller is still unable to achieve backward and turning motion with a body length radius,and the hydrodynamic pitch moment acting on the HUG that is mainly caused by the fixed-wing makes it difficult to achieve high-precision attitude control during fixed-depth *** solve this problem,a two-degree-of-freedom bioinspired controllable wing mechanism(CWM)is proposed to improve the maneuverability and cruising ability of *** CWM can realize five motion modes:modifying the dihedral angle or anhedral angle,changing the frontal area of the wing,switching the wing from horizontal to be a vertical rudder,flapping the wing as propulsion,and rotating the wing as a vector ***,the design process of the CWM is provided,and hydrodynamic forces in each motion mode of three CWMs with different trailing edge sweepback angles(TESA)and attitude angles are analyzed through computational fluid dynamics *** relationship between hydrodynamics and the attitude angles or TESA of the CWM is ***,experiments are conducted to measure the hydrodynamics of the CWM when it is in a flapping wing mode and rotating the wing as a vector propeller,*** hydrodynamic forces obtained from the simulation are consistent with data measured by a force sensor,proving the credibility of the simulated ***,by applying the results of the hydrodynamic force in this study,the flapping trajectory of the wingtip is planned using the cubic spline interpolation ***,two underwater demo vehicles with a pair of CWMs are developed,and experiments are conducted in a water tank,further validating and demonstrating the feasibility of the proposed CWM.

关键词： controllable wing mechanism hybrid-driven underwater glider bioinspired design multi-locomotion modes

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