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Spacecraft formation-containment flying control with time-varying translational velocity

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Chinese Journal of Aeronautics 2020年第1期33卷 271-281页

作者： Liangming chen Chuanjiang LI yanning GUO Guangfu MA Baolong ZHU Department of Control Science and Engineering Harbin Institute of TechnologyHarbin 150001China School of Electrical Engineering and Automation Qilu University of Technology(Shandong Academy of Sciences)Jinan 250353China

This paper investigates the problem of Spacecraft Formation-Containment Flying Control(SFCFC)when the desired translational velocity is time-varying.In SFCFC problem,there are multiple leader spacecraft and multiple follower spacecraft and SFCFC can be divided into leader spacecraft’s formation control and follower spacecraft’s containment control.First,under the condition that only a part of leader spacecraft can have access to the desired time-varying translational velocity,a velocity estimator is designed for each leader spacecraft.Secondly,based on the estimated translational velocity,a distributed formation control algorithm is designed for leader spacecraft to achieve the desired formation and move with the desired translational velocity simultaneously.Then,to ensure all follower spacecraft converge to the convex hull formed by the leader spacecraft,a distributed containment control algorithm is designed for follower spacecraft.Moreover,to reduce the dependence of the designed control algorithms on the graph information and increase system robustness,the control gains are changing adaptively and the parametric uncertainties are handled,respectively.Finally,simulation results are provided to illustrate the effectiveness of the theoretical results.

关键词： Adaptive gain technique Distributed control Formation-containment Formation control Spacecraft formation flying

Development of metal-organic framework(MOF) decorated graphene oxide/Mg Al-layered double hydroxide coating via microstructural optimization for anti-corrosion micro-arc oxidation coatings of magnesium alloy

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Journal of Materials Science & Technology 2022年第35期130卷 12-26页

作者： Yanning Chen Liang Wu Wenhui Yao Jiahao Wu Jianpeng Xiang Xiaowei Dai Tao Wu Yuan Yuan Jingfeng Wang Bin Jiang Fusheng Pan College of Materials Science and Engineering Chongqing UniversityChongqing 400044China National Engineering Research Center for Magnesium Alloys Chongqing UniversityChongqing 400044China

An efcient and simple in-situ growth strategy has been discovered for the preparation of highly reproducible and continuous symbiotic ZIF-8-based anticorrosion coating by using graphene oxide(GO)/Mg AlNO3layered double hydroxides(G/LDHs) buffer layer as a new type of connecting carrier based on micro-arc oxide(MAO) coating of AZ31 magnesium alloy. The components of ZIF-8 were adsorbed and bounded to the surface of the G/LDHs buffer layer-modified substrates to promote the nucleation of ZIF-8,thus growing a phase-pure, uniform, and good symbiosis ZIF-8 membrane. ZIF-8 particles with different growth times compensate for the grain boundary defects of the G/LDHs coating precursor buffer layer to different degrees. The prepared ZIF-8-based coating has excellent stability and corrosion resistance. The results demonstrate that the G/LDHs buffer layer provides a new channel for the MOF-modified MAO substrate of AZ31 magnesium alloy. It also proves that it is feasible to build high-performance anticorrosive coatings with MOF materials.

关键词： Zeolitic-imidazole framework Layered double hydroxide Graphene oxide Micro-arc oxidation Corrosion protection Magnesium alloy

MgAl-V_(2)O_7 ^(4-)LDHs/(PEI/MXene)_(10) composite film for magnesium alloy corrosion protection

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Journal of Materials Science & Technology 2021年第32期91卷 28-39页

作者： Yulong Wu Liang Wu Mikhail L.Zheludkevich Yanning Chen Maria Serdechnova Wenhui Yao Carsten Blawert Andrej Atrens Fusheng Pan State Key Laboratory of Mechanical Transmission College of Materials Science and EngineeringChongqing UniversityChongqing 400044China National Engineering Research Center for Magnesium Alloys Chongqing UniversityChongqing 400044China Institute of Surface Science Helmholtz-Zentrum HereonMax-Planck Str.121502 GeesthachtGermany School of Mechanical and Mining Engineering The University of QueenslandBrisbaneQld 4072Australia

In this study,MgAl-V_(2) O_7^(4-) LDHs/(poly(ethyleneimine)(PEI)/MXene)_n composite films were synthesized via(ⅰ) in-situ hydrothermal growth of Mg-AL layered double hydroxides(LDHs) on AZ31 alloy followed by vanadate intercalation reactions,and(ⅱ) the as-prepared MgAL-V_(2) O7^(4-) LDHs film was covered by layerby-layer assembly using(PEI/MXene)_n,where n=5,10,and 20.Film characterization revealed that the outer layers(PEI/MXene) were assembled on the surface by electrostatic interaction and provided a good coverage of LDHs nanosheets.But,microcracks appeared gradually on the surface and destroyed the film integrity with increasing number of PEI/MXene layers.The corrosion tests indicated that the MgAl-V_(2) O_7^(4-)LDHs/(PEI/MXene)_(10) composite films provided a better corrosion protection ability than that of n=5 and20.The outer layers(PEI/MXene) had a corrosion inhibition protective effect on MgAl-V_(2) O_7^(4-) LDHs film.This work opened a new perspective of the MXene materials for anticorrosion application via a layer-bylayer assembly method.

关键词： Magnesium alloys Layered double hydroxides Vanadate MXene Layer-by-Layer Corrosion resistance

Effect of remimazolam vs. propofol on hemodynamics during general anesthesia induction in elderly patients: Single-center, randomized controlled trial

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The Journal of Biomedical Research 2024年第1期38卷 66-75页

作者： Mingfeng He Chanjuan Gong Yinan chen Rongting chen yanning Qian Department of Anesthesiology and Perioperative Medicine the First Affiliated Hospital of Nanjing Medical UniversityNanjingJiangsu 210029China

The current study aimed to compare the effects between remimazolam and propofol on hemodynamic stability during the induction of general anesthesia in elderly patients.We used propofol at a rate of 60 mg/(kg·h)in the propofol group(group P)or remimazolam at a rate of 6 mg/(kg·h)in the remimazolam group(group R)for the induction.A processed electroencephalogram was used to determine whether the induction was successful and when to stop the infusion of the study drug.We measured when patients entered the operating room(T_(0)),when the induction was successful(T_(1)),and when before(T_(2))and 5 min after successful endotracheal intubation(T_(3)).We found that mean arterial pressure(MAP)was lower at T_(1–3),compared with T_(0) in both groups,but higher at T_(2) in the group R,whileΔMAP_(T0–T2) andΔMAP_(max) were smaller in the group R(ΔMAP_(T0–T2):the difference between MAP at time point T_(0) and T_(2),ΔMAP_(max):the difference between MAP at time point T_(0) and the lowest value from T_(0) to T_(3)).Cardiac index and stroke volume index did not differ between groups,whereas systemic vascular resistance index was higher at T_(1–3) in the group R.These findings show that remimazolam,compared with propofol,better maintains hemodynamic stability during the induction,which may be attributed to its ability to better maintain systemic vascular resistance levels.

关键词： remimazolam propofol elderly patients hypotension left ventricular systolic function systematic vascular resistance

Boosting efficiency and stability of 2D alternating cation perovskite solar cells via rational surface-modification: Marked passivation efficacy of anion

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Journal of Energy Chemistry 2023年第9期84卷 354-362页

作者： Hualin Zheng Xuefeng Peng Tingxi chen Ting Zhang Shihao Yuan Lei Wang Feng Qian Jiang Huang Xiaodong Liu Zhi David chen yanning Zhang Shibin Li State Key Laboratory of Electronic Thin Films and Integrated Devices and School of Optoelectronic Science and EngineeringUniversity of Electronic Science and Technology of China(UESTC)Chengdu 610054SichuanChina Institute of Fundamental and Frontier Sciences University of Electronic Science and Technology of China(UESTC)Chengdu 610054SichuanChina Department of Electrical&Computer Engineering and Center for Nanoscale Science&EngineeringUniversity of KentuckyLexingtonKY 40506USA Institute of Electronic and Information Engineering of UESTC in Guangdong Dongguan 523808GuangdongChina

Two-dimensional(2D) alternating cation(ACI) perovskite surface defects,especially dominant iodine vacancies(V_Ⅰ) and undercoordinated Pb^(2+),limit the performance of perovskite solar cells(PVSCs).To address the issue,1-butyl-3-methylimidazolium trifluoro-methane-sulfonate(BMIMOTF) and its iodide counterpart(BMIMI) are utilized to modify the perovskite surface respectively.We find that BMIMI can change the perovskite surface,whereas BMIMOTF shows a nondestructive and more effective defect passivation,giving significantly reduced defect density and suppressed charge-carrier nonradiative recombination.This mainly attributes to the marked passivation efficacy of OTF-anion on V_Ⅰ and undercoordinated Pb^(2+),rather than BMIMI^(+) cation.Benefiting from the rational surface-modification of BMMIMOTF,the films exhibit an optimized energy level alignment,enhanced hydrophobicity and suppressed ion migration.Consequently,the BMIMOTF-modified devices achieve an impressive efficiency of 21.38% with a record open-circuit voltage of 1.195 V,which is among the best efficiencies reported for 2D PVSCs,and display greatly enhanced humidity and thermal stability.

关键词： 2D ACI perovskite solar cells Charge-carrier nonradiative recombination Surface defects passivation Energy level alignment Ionic migration Stability

Synergistic effect of phosphorus doping and MoS_(2) co-catalysts on g-C_(3)N_(4) photocatalysts for enhanced solar water splitting

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Journal of Materials Science & Technology 2023年第27期158卷 171-179页

作者： Xunfu Zhou Pai Wang Meng Li Minfu Wu Bei Jin Jin Luo Meifeng chen Xiaoqin Zhou yanning Zhang Xiaosong Zhou School of Chemistry and Chemical Engineering Key Laboratory of Clean Energy Materials Chemistry of Guangdong Higher Education InstitutesLingnan Normal UniversityZhanjiangGuangdong 524048China Institute of Fundamental and Frontier Sciences University of Electronic Science and Technology of ChinaChengdu 611731China Electrochemical NanoEnergy Group School of Chemical Engineering and Light Industry at Guangdong University of TechnologyGuangzhou 510006China Department of Food Science Foshan Polytechnic Foshan 528137China

Carbon nitride(g-C_(3)N_(4))is a promising metal-free and visible-light-responsive photocatalyst.However,its photocatalytic efficiency still suffers from high recombination rates of photoinduced charge carriers,slow kinetics of surface redox reactions,and relatively poor light absorption.Herein,a non-noble metal photocatalyst of MoS_(2) nanodots anchored on P-doped g-C_(3)N_(4) via in situ photodeposition was constructed.With the synergetic effect of the P-doping and MoS_(2) co-catalyst,the as-prepared P-doped g-C_(3)N_(4)/MoS_(2) catalyst has achieved efficient photocatalytic overall water splitting with a hydrogen evolution rate of 121.7μmol h−1 g−1.Experimental results and Density functional theory(DFT)simulations indicate that the enhanced photo-absorption capacity originates from the reduced band gaps by P doping.Meanwhile,the MoS_(2) reduces the overpotential of the water oxidation process and improves hydrogen adsorption capability in the hydrogen evolution reaction.This work can pave a new avenue to design and develop noble-metal-free water-splitting photocatalysts for future large-scale applications.

关键词： Synergistic effect Noble-metal-free photocatalyst P-doping MoS_(2)co-catalyst Water splitting g-C_(3)N_(4)

Genesis and Uranium Sources of Leucogranite-hosted Uranium Deposits in the Gaudeanmus Area, Central Damara Belt, Namibia: Study of Element and Nd Isotope Geochemistry

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Acta Geologica Sinica(English Edition) 2017年第6期91卷 2126-2137页

作者： FAN Honghai chen Jinyong WANG Shengyun ZHAO Jingyang GU Dazhao MENG yanning Beijing Research Institute of Uranium Geology Key Laboratory of Uranium Resource Exploration and Evaluation Technology CNNC Department of Earth Sciences and State Key Lab of Mineral Deposit Research Nanjing University

This paper presents a systematic study of major and trace elements and Sm-Nd isotopes in leucogranites closely related to uranium mineralization in the Gaudeanmus area, Namibia. The results illustrate that the uraniferous leucogranites possess high SiO2 （68.8wt%-76.0wt%, average 73.1wt%） and K （4.05wt%-7.78wt%, average 5.94wt%） contents, and are sub-alkaline and metaluminous to weakly peraluminous, as reflected by A/CNK values of 0.96-1.07 with an average of 1.01. The leucogranites are rich in light rare earth elements （LREE/HREE = 2.53-7.71; （La/Yb）s = 2.14-10.40）, have moderate Eu depletion and high Rb/Sr ratios （2.03-5.50 with an average of 4.36）; meanwhile, they are enriched in Rb, K, Th, U and Pb, and depleted in Ba, Nb, Ta, and Sr. The tNd（t） values of uraninites range from -14.8 to -16.5, and the two-stage Nd model ages are 2.43-2.56 Ga. Detailed elemental and Sm-Nd isotopic geochemical characteristics suggest that the leucogranites were formed in a post- orogenic extensional environment. The U-rich pre-Damara basement was the main source of uranium during the primary mineralization event, which is disseminated in leucogranites, whereas the uranium mineralization in veins possibly resulted from remobilization of the primary uranium minerals.

关键词： uranium source of uranium Nd isotopes leucogranites Gaudeanmus Damara Belt

Cell concentration,viability and culture composition of airborne bacteria during a dust event in Beijing

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Journal of Environmental Sciences 2017年第5期29卷 33-40页

作者： Hongli Yuan Daizhou Zhang yanning Shi Baozhen Li Jinshui Yang Xuejian Yu Nan chen Makiko Kakikawa State Key Laboratory of Agrobiotechnology College of Biological SciencesChina Agricultural University Faculty of Environmental and Symbiotic Sciences Prefectural University of Kumamoto Institute of Nature and Environmental Technology Kanazawa University

Airborne bacteria were measured when a dust storm passed Beijing in spring 2012 with a focus on cell concentration, viability and TSA- and R2A-cultured strain composition. The concentration varied at an order of 10^7 cells/m3 with dust loading （demonstrated with PM10） and they had a very close correlation （RT2 = 0.91, p 〈 0.01）. At the time of highest PM10 of 652 μg/m3, the bacterial concentration reached 1.4 × 10^8 cells/m3, which was larger than that before and after the dust event by one order. Bacterial viability, the ratio of number concentration of viable cells to total cells, was 32%-64% and smaller in the dust plume than that before the dust arrival. Bacterial strains from the culture ranged between 2.5 × 10^4 and 4.6 × 10^5 CFU/m3 and no correlation with PM10 was determined. Their composition was different before and after the dust arrival according to 16S rRNA gene sequences and strains belong to Actinomycetes and Firmicutes were the majority in the dust samples.

关键词： Bacteria Asian dust Beijing Fluorescence enumeration PM10

Interfacial engineering of Ni/V2O3 for hydrogen evolution reaction

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Nano Research 2020年第9期13卷 2407-2412页

作者： Yang chen Yuan Rao Rongzhi Wang Yanan Yu Qiulin Li Shujuan Bao Maowen Xu Qin Yue yanning Zhang Yijin Kang Institute of Fundamental and Frontier Sciences University of Electronic Science and Technology of ChinaChengdu 610054China Key Laboratory of Luminescent and Real-Time Analytical Chemistry Ministry of EducationInstitute for Clean Energy and Advanced MaterialsFaculty of Materials and EnergySouthwest UniversityChongqing 400715China

Electrocatalytic water splitting offers a sustainable route for hydrogen production,enabling the clean and renewable alternative energy system of hydrogen economy.The scarcity and high-cost of platinum-group-metal(PGM)materials urge the exploration of high-performance non-PGM electrocatalysts.Herein,a unique hierarchical structure of NiA/2O3 with extraordinary electrocatalytic performance(e.g.t overpotentials as low as 22 mV at 20 mA·cm^-2 and 94 mV at 100 mA·cm^-2)toward hydrogen evolution reaction in alkaline electrolyte(1 M KOH)is reported.The investigation on the hierarchical NiA/2O3 with a bimodal size-distribution also offers insight of interfacial engineering that only proper NiA/2O3 interface can effectively improve H20 adsorption,H20 dissociation as well as H adsorption,for an efficient hydrogen production.

关键词： hydrogen evolution reaction hierarchical materials interface electrocatalysis vanadium oxide