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Effect of Water Absorption on the Mechanical Property and Failure Mechanism of Hollow Glass Microspheres Composite Epoxy Resin Solid Buoyancy Materials

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China Ocean Engineering 2023年第5期37卷 876-884页

作者： DING Yue ZHAI Gang-jun MA Zhe WEI Zi-hao LI Xin State Key Laboratory of Coastal and Offshore Engineering Dalian University of TechnologyDalian 116024China Faculty of Infrastructure Engineering Dalian University of TechnologyDalian 116024China

To study the water absorption of hollow glass microspheres(HGMs)composite epoxy resin solid buoyancy materials in the marine environment and its effect on the mechanical properties,the water absorption was measured by immersing the material in distilled water for 36 days at ambient temperature and fitted to Fick’s second *** strength of materials before and after water absorption were tested by uniaxial experiments,and the effects of the filling ratio and water absorption on the mechanical properties of the materials were analyzed and ***,the failure modes and mechanism of the hollow glass microspheres composite material were explicated from the microscopic level by scanning electron microscope(SEM).This research will help solve the problems of solid buoyancy materials in ocean engineering applications.

关键词： solid buoyancy material water absorption mechanical property failure mechanism scanning electron microscope

High-operating-temperature mid-infrared photodetectors via quantum dot gradient homojunction

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Light(Science & Applications) 2023年第3期12卷 355-365页

作者： Xiaomeng Xue Menglu Chen Yuning Luo Tianling Qin Xin Tang Qun hao School of Optics and Photonics Beijing Institute of TechnologyNo.5 Zhongguancun South StreetBeijingChina Beijing Key Laboratory for Precision Optoelectronic Measurement Instrument and Technology BeijingChina Yangtze Delta Region Academy of Beijing Institute of Technology BeijingChina

Due to thermal carriers generated by a narrow mid-infrared energy gap,cooling is always necessary to achieve ideal *** quantum dot(QD),the electron thermal generation should be reduced with quantum confinement in all three *** a result,there would be a great potential to realize high-operating-temperature(HOT)QD mid-IR photodetectors,though not yet *** the advantages of colloidal nanocrystals’solution processability and precise doping control by surface dipoles,this work demonstrates a HOT mid-infrared photodetector with a QD gradient *** detector achieves background-limited performance with D^(*)=2.7×1011 Jones on 4.2μm at 80 K,above 10^(11) Jones until 200 K,above 10^(10 )Jones until 280 K,and 7.6×10^(9) Jones on 3.5μm at 300 *** external quantum efficiency also achieves more than 77%with responsivity 2.7 A/W at zero *** applications such as spectrometers,chemical sensors,and thermal cameras,are also approved,which motivate interest in low-cost,solution-processed and high-performance mid-infrared photodetection beyond epitaxial growth bulk photodetectors.

关键词： quantum gradient precise

Lubrication condition monitoring of journal bearings in diesel engine based on thermoelectricity

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Friction 2024年第11期12卷 2532-2547页

作者： Yuhao LV hao LIU Zhigang CHEN Weijie CHANG Hui ZHANG Hulin LI Shanghai Jiao Tong University Shanghai 200240China National Key Laboratory of Marine Engine Science and Technology Shanghai 201108China Shanghai Marine Diesel Engine Research Institute Shanghai 201108China Hunan Aviation Powerplant Research Institute Aero Engine Corporation of ChinaHunan 412002China

There is still a lack of effective lubrication condition monitoring methods in the field of diesel *** paper proposes a novel thermoelectric approach to divide the lubrication state of ***,the generation mechanism of thermoelectric potential on bearings is ***,both experimental and simulation studies are done,and a strong correlation between lubrication and thermoelectric potential is *** film thickness and temperature are further confirmed as significant factors influencing thermoelectric ***,the thermoelectric potential increases with ***,a small film thickness ratio(when the film thickness ratio is less than 4)will suppress the thermoelectric *** typical lubrication states of bearings are distinguished through thermoelectric potential and supported by the Stribeck curve ***,the significant influence of lubrication on the bearing is confirmed through the analysis of surface morphology and composition.

关键词： journal bearing lubrication state,thermoelectric potential condition monitoring

Characterization of time-and size-dependent particle emissions and decay from cooking oil fumes in residence:Impacts of various intervention measures

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Building Simulation 2023年第7期16卷 1149-1158页

作者： Jianbang Xiang Linmin Hu Jiayuan hao Siqing Wu Jianping Cao Edmund Seto School of Public Health(Shenzhen) Sun Yat-sen UniversityShenzhenGuangdong 518107China State Environmental Protection Key Laboratory of Sources and Control of Air Pollution Complex Beijing 100084China Division of Environmental Health University of Southern CaliforniaLos AngelesCA 90032USA School of Medicine Sun Yat-sen UniversityShenzhenGuangdong 518107China School of Environmental Science and Engineering Sun Yat-sen UniversityGuangzhouGuangdong 510006China Department of Environmental and Occupational Health Sciences University of WashingtonSeattleWA 98195USA

The dynamic characteristics of cooking-related particle size distributions in real-world settings are not fully *** a real-world campaign in a naturally-ventilated apartment in the northwest US,this study investigates the temporal profiles of size-resolved particle number concentrations(PNCs)ranging from 0.3 to 10µm from frying cooking *** cooking scenarios included various combinations of window ventilation,venting range hood(VRH)use,and portable air cleaner(PAC)*** a standardized pan-frying protocol throughout seven scenarios,real-time PNCs of 16-size bins were measured in the *** PNCs were empirically compared among size bins,periods,and *** most abundant size ranges of cooking-related particles were 0.3–0.579µm in number(45%–71%of the total)and 2.685–5.182µm in mass(48%–57%of the total).Compared with the scenario without any cooking-fume mitigating measures,keeping the kitchen windows open reduced the mean PNCs during and within 1-h after cooking for PM_(0.3-2.5),PM_(2.5-10),and PM_(0.3-10)by 78%,92%,and 79%,*** contrast,utilizing a VRH during cooking reduced the corresponding levels by 21%,69%,and 25%,*** with running the VRH,using a PAC in the kitchen led to additional reductions of 84%,88%,and 84%,***,the removal efficiencies of the three strategies generally increased with particle sizes.

关键词： cooking oil fumes size-resolved particles venting range hood window ventilation portable air cleaner

Modelling the viscoplastic behaviour of Callovo-Oxfordian claystone with consideration of damage effect

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第1期16卷 303-316页

作者： hao Wang Yu-Jun Cui Minh Ngoc Vu Jean Talandier Ecole des Ponts ParisTech Laboratoire Navier/CERMES6 et 8 avenue Blaise PascalMarne La Vallée cedex 277455France Andra R&D DepartmentChâtenay-Malabry92290France

In order to evaluate the performance of deep geological disposal of radioactive waste,an underground research laboratory(URL)was constructed by Andra in the Callovo-Oxfordian(COx)claystone formation at the Meuse/Haute-Marne(MHM).The construction of URL induced the excavation damage of host formations,and the ventilation in the galleries desaturated the host formation close to the gallery ***,it is expected that the mechanical behaviour of COx claystone is *** study presents a constitutive model developed to describe the viscoplastic behaviour of unsaturated and damaged COx *** this model,the unsaturation effect is considered by adopting the Bishop effective stress and the van Genuchten(VG)water retention *** terms of the viscoplastic behaviour,the nonstationary flow surface(NSFS)theory for unsaturated soils is used with consideration of the coupled effects of strain rate and suction on the yield stress.A progressive hardening law is ***,a non-associated flow rule is used,which is similar to that in Barcelona basic model(BBM).In addition,to describe the damage effect induced by suction change and viscoplastic loading,a damage function is defined based on the crack volume *** damage function contains two variables:unsaturated effective stress and viscoplastic volumetric strain,with the related parameters determined based on the mercury intrusion porosimetry(MIP)*** the model validation,different tests on COx claystone under different loading paths are *** between experimental and simulated results indicated that the present model is able to well describe the viscoplastic behaviour of damaged COx claystone,including swelling/shrinkage,triaxial extension and compression,and triaxial creep.

关键词： Callovo-Oxfordian(COx)claystone Excavation damage Time-dependent behaviour Suction Viscoplastic model

Stackelberg Game for Wireless Powered and Backscattering Enabled Sensor Networks

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China Communications 2024年第3期21卷 189-204页

作者： Lyu Bin Cao Yi Wang Shuai Guo Haiyan hao Chengyao Key Laboratory of Ministry of Education in Broadband Wireless Communication and Sensor Network Technology Nanjing University of Posts and TelecommunicationsNanjing 210003China Jiangsu Engineering Research Center of Novel Optical Fiber Technology and Communication Network Suzhou 215006China Guangdong-Hong Kong-Macao Joint Laboratory of Human-Machine Intelligence-Synergy Systems Shenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhen 518055China

This paper investigates a wireless powered and backscattering enabled sensor network based on the non-linear energy harvesting model, where the power beacon(PB) delivers energy signals to wireless sensors to enable their passive backscattering and active transmission to the access point(AP). We propose an efficient time scheduling scheme for network performance enhancement, based on which each sensor can always harvest energy from the PB over the entire block except its time slots allocated for passive and active information delivery. Considering the PB and wireless sensors are from two selfish service providers, we use the Stackelberg game to model the energy interaction among them. To address the non-convexity of the leader-level problem, we propose to decompose the original problem into two subproblems and solve them iteratively in an alternating manner. Specifically, the successive convex approximation, semi-definite relaxation(SDR) and variable substitution techniques are applied to find a nearoptimal solution. To evaluate the performance loss caused by the interaction between two providers, we further investigate the social welfare maximization problem. Numerical results demonstrate that compared to the benchmark schemes, the proposed scheme can achieve up to 35.4% and 38.7% utility gain for the leader and the follower, respectively.

关键词： backscatter communication energy interaction stackelberg game wireless powered sensor network

Digital signal acquisition system for complex nuclear reaction experiments

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Nuclear Science and Techniques 2024年第1期35卷 124-133页

作者： Wei-Liang Pu Yan-Lin Ye Jian-Ling Lou Jia-hao Chen School of Physics and State Key Laboratory of Nuclear Physics and Technology Peking UniversityBeijing 100871China Institute of Applied Physics and Computational Mathematics Beijing 100094China

A digital data-acquisition system based on XIA LLC products was used in a complex nuclear reaction experiment using radioactive ion beams.A flexible trigger system based on a field-programmable gate array(FPGA)parametrization was developed to adapt to different experimental sizes.A user-friendly interface was implemented,which allows converting script language expressions into FPGA internal control *** proposed digital system can be combined with a conventional analog data acquisition system to provide more *** performance of the combined system was veri-fied using experimental data.

关键词： Digital signal acquisition system Trigger Programmable logic Timestamp

Thermodynamic modeling and phase diagram prediction of salt lake brine systemsⅡ.Aqueous Li^(+)-Na^(+)-K^(+)-SO_(4)^(2-) and its subsystems

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Chinese Journal of Chemical Engineering 2021年第6期34卷 134-149页

作者： Huan Zhou Peng Wu Wenxuan Li Xingfan Wang Kuo Zhou Qing hao College of Chemical Engineering and Materials Science Tianjin Key Laboratory of Brine Resources and Eco-utilizationTianjin University of Science and TechnologyTianjin 300457China College of Marine and Environmental Sciences Tianjin Key Laboratory of Brine Resources and Eco-utilizationTianjin University of Science and TechnologyTianjin 300457China

It is still a challenging task to accurately and temperature-continuously express the thermodynamic properties and phase equilibrium behaviors of the salt-lake brine with multi-component,multitemperature and high *** essential subsystem of sulfate type brine,aqueous Li^(+)-Na^(+)-K^(+)-SO_(4)^(2-) and its subsystems across a temperature range from 250 K to 643 K are investigated with the improved comprehensive thermodynamic *** parameters(Δg_(IJ),Δh_(IJ),and ΔC_(p,IJ))associated with the contributions of Gibbs energy,enthalpy,and heat capacity to the binary interaction parameters,*** temperature coefficients of eNRTL parameters formulated with a Gibbs Helmholtz expression,are determined via multi-objective optimization *** solid constantsΔ_(f)G_(k)°^((298.15))andΔ_(f)H_(k)°^((298.15))of11 solid species occurred in the quaternary system are rebuilt from multi-temperature *** modeling results show the accurate representation of(1)solution properties and binary phase diagram at temperature ranges from eutectic points to 643 K;(2)isothermal phase diagrams for Li_(2)SO_(4)-Na_(2)SO_(4)-H_(2)O,Li_(2)SO_(4)-K_(2)SO_(4)-H_(2)O and Na_(2)SO_(4)-K_(2)SO_(4)-H_(2)O ternary *** predicted results of complete structure and polythermal phase diagram of ternary systems and the isothermal phase diagrams of quaternary system excellently match with the experimental data.

关键词： Aqueous electrolytes Comprehensive thermodynamic model Aqueous Li^(+)-Na^(+)-K^(+)-SO_(4)^(2-) Phase diagram Thermodynamic properties

Anion-derived solid electrolyte interphase realized in usualconcentration electrolyte for Li metal batteries

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Nano Research 2023年第11期16卷 12647-12654页

作者： Zhimeng hao Geng Li Yong Lu Yichao Cai Gaojing Yang Jun Chen Frontiers Science Center for New Organic Matter Haihe Laboratory of Sustainable Chemical TransformationsKey Laboratory of Advanced Energy Materials Chemistry(Ministry of Education)College of ChemistryNankai UniversityTianjin 300071China National Supercomputer Center in Tianjin Tianjin 300457China

Constructing anion-derived solid electrolyte interphase(SEI)by recruiting anions into the solvation sheath of Li+is extremely conducive to restrain the dendrite growth of Li metal ***,the presence of anions in the solvation sheath of Li+is severely hindered by the solvents with strong coordinating ability in conventional ***,we boost the content of anions in the primary solvation sheath of Li+by employing a solvent with low donor number,2-methyltetrahydrofuran,inducing an anion-derived *** a result,the Li||Cu cells show a high average Coulombic efficiency(>99%)over 500 cycles and the Li||LiFePO4 cells under a low negative/positive capacity ratio of 2:1 exhibit an impressive capacity retention of 90%after 100 *** work provides insights on constructing stable anion-derived SEI and offers guidance in designing electrolytes for stable Li metal batteries.

关键词： anion-derived solid electrolyte interphase donor number solvating power electrolyte lithium metal batteries