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Fluid-structure interaction simulation for multi-body flexible morphing structures

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Chinese Journal of Aeronautics 2024年第2期37卷 137-147页

作者： Wenzhi GUO Yongtao SHUI Lu nie Gang CHEN State Key Laboratory of Strength and Vibration for Mechanic Structures School of Aerospace EngineeringXi’an Jiaotong UniversityXi’an 710049China China Academy of Launch Vehicle Technology Beijing 100076China China Academy of Aerospace Science and Innovation Beijing 100086China Shannxi Key Laboratory of Service Environment and Control for Flight Vehicles Xi’an Jiaotong UniversityXi’an 710049China

The multi-body flexible morphing airfoil can improve the aerodynamic characteristics based on different flight missions *** researches have focused on the unsteady aerodynamic characteristics of flexible wings under passive ***,the unsteady aerodynamic characteristics with the fluid-structure interaction effects in the multi-body active actuation process of morphing airfoil deserve further *** this paper,a fluid-structure coupled simulation method for multi-body flexible morphing airfoil with active actuation subsystem was investigated,and the aerodynamic characteristics during deformation were compared with different skin flexibility,flow field environment,actuation mode and actuation *** numerical results show that for the steady aerodynamic,the skin flexibility can improve the stability *** the unsteady process,the change trend of the transient lift coefficient and pitching moment are consistent with those of the active drive characteristics,while the instantaneous lift-drag ratio coefficient is greatly affected by the driving mode and can be improved by increasing the driving duration.

关键词： Fluid-structure interaction Multi-body dynamics modeling Flexible structures Aerodynamics Morphing wings

Bulging Distortion of Austenitic Stainless Steel Sheet on the Partially Penetrated Side of Non-Penetration Lap Laser Welding Joint

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Chinese Journal of Mechanical Engineering 2024年第1期37卷 286-295页

作者： Chengwu Yao Enze Liu Jiaming Ni Binying nie Shanghai Key Laboratory of Materials Laser Processing and Modification School of Material Science and EngineeringShanghai Jiao Tong UniversityShanghai 200240China Shanghai Aerospace Precision Machinery Institute Shanghai 201600China Chemical and Biological Engineering College Yichun UniversityYichun 336000China

Non-penetration laser welding of lap joints in austenitic stainless steel sheets is commonly preferred in fields where the surface quality is of utmost ***,the application of non-penetration welded austenitic stainless steel parts is limited owing to the micro bulging distortion that occurs on the back surface of the partial penetration *** this paper,non-penetration lap laser welding experiments,were conducted on galvanized and SUS304 austenitic stainless steel plates using a fiber laser,to investigate the mechanism of bulging distortion.A comparative experiment of DC01 galvanized steel-Q235 carbon steel lap laser welding was carried out,and the deflection and distortion profile of partially penetrated side of the sheets were measured using a noncontact laser *** addition,the cold-rolled SUS304 was subjected to heat holding at different temperatures and water quenching after bending to characterize its microstructure under tensile and compressive *** results show that,during the heating stage of the thermal cycle of laser lap welding,the partial penetration side of the SUS304 steel sheet generates compressive stress,which extrudes the material in the heat-affected zone to the outside of the back of the SUS304 steel sheet,thereby forming a *** findings of these experiments can be of great value for controlling the distortion of the partial penetrated side of austenitic stainless steel sheet during laser non-penetration lap welding.

关键词： Non-penetration lap laser welding Bulging distortion Austenitic stainless steel Compressive stress Tension stress

Reverse metabolomics as a novel strategy to annotate the human metabolome

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Chinese Journal of Natural Medicines 2024年第4期22卷 289-290页

作者： YAN Tingting nie Liangliang HAO Haiping State Key Laboratory of Natural Medicines China Pharmaceutical UniversityNanjing 211198China Laboratory of Metabolic Regulation and Drug Target Discovery School of PharmacyChina Pharmaceutical UniversityNanjing 210009China

Identifying chemical structures inhuman-derived samples presents significant challenges due to limited structural data obtained from untargeted metabolomics *** the chemical structures of molecules are closely related to the phenotypic status of human ecosystems,it becomes invaluable to devise a method for efficiently and systematically determining structures that correlate with the pathophysiological status of humans in a high-throughput approach.

关键词： Reverse metabolomics Human metabolome Combinational synthesis Bile amidates

Natural forests exhibit higher organic carbon concentrations and recalcitrant carbon proportions in soil than plantations:a global data synthesis

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Journal of Forestry Research 2024年第5期35卷 131-141页

作者： Xiuqing nie Hui Wang Jian Wang Shirong Liu Ecology and Nature Conservation Institute Chinese Academy of ForestryKey Laboratory of Forest Ecology and Environment of National Forestry and Grassland AdministrationNo.2 DongxiaofuHaidian DistrictBeijing 100091People’s Republic of China

Different chemical compositions of soil organic carbon(SOC)affect its persistence and whether it signifi-cantly differs between natural forests and plantations remains *** synthesizing 234 observations of SOC chemical compositions,we evaluated global patterns of concentra-tion,individual chemical composition(alkyl C,O-alkyl C,aromatic C,and carbonyl C),and their distribution *** results indicate a notably higher SOC,a markedly larger proportion of recalcitrant alkyl C,and lower easily decomposed carbonyl C proportion in natural ***-ever,SOC chemical compositions were appreciably more evenly distributed in *** on the assumed con-ceptual index of SOC chemical composition evenness,we deduced that,compared to natural forests,plantations may have higher possible resistance to SOC decomposition under *** tropical regions,SOC levels,recalcitrant SOC chemical composition,and their distributed evenness were significantly higher in natural forests,indicating that SOC has higher chemical stability and possible resistance to *** factors had minor effects on alkyl C in forests globally,while they notably affected SOC chemi-cal composition in tropical *** could contribute to the differences in chemical compositions and their distrib-uted evenness between plantations and natural stands.

关键词： Global data synthesis Natural forest Plantations Soil organic carbon Soil organic carbon chemical composition

Improving the underwater navigation performance of an IMU with acoustic long baseline calibration

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Satellite Navigation 2024年第1期5卷 224-239页

作者： Paipai Wu Wenfeng nie Yangfan Liu Tianhe Xu Shandong Key Laboratory of Optical Astronomy and Solar-Terrestrial Environment Institute of Space SciencesShandong UniversityWeihai264209ShandongChina Research Group of Astronomy and Geomatics(gAGE) Universitat Politecnica de Catalunya(UPC)BarcelonaSpain

Underwater acoustic Long-Baseline System(LBL)is an important technique for submarine positioning and ***,the high cost of the seafloor equipment and complex construction of a seafloor network restrict the distribution of the LBL within a small area,making an underwater vehicle difficult for long-distance and high-precision acoustic-based or inertial-based *** therefore propose an acoustic LBL-based Inertial Measurement Unit(IMU)calibration *** the underwater vehicle can receive the acoustic signal from a seafloor beacon,the IMU is precisely calibrated to reduce the cumulative error of Strapdown Inertial Navigation System(SINS).In this way,the IMU is expected to maintain a certain degree of accuracy by relying solely on SINS when the vehicle reaches out the range of the LBL network and cannot receive the acoustic *** present the acoustic LBL-based IMU online calibration model and analyze the factors that affect the accuracy of IMU *** results fulfill the expectation that the gyroscope bias and accelerometer bias are the main error sources that affect the divergence of SINS position errors,and the track line of the underwater vehicle directly affects the accuracy of the calibration *** addition,we deduce that an optimal calibration trajectory needs to consider the effects of the three-dimensional observability and position dilution of *** the experiment,we compare the effects of seven calibration trajectories:straight and diamond-shaped with and without the change of depth,and three sets of curves with the change of depth:circular,S-shaped,and *** them,we find that the figure-eight is the optimal trajectory for acoustic LBL-based IMU online *** take the maintenance period during which the accumulated SINS Three Dimensional(3D)position errors are below 1 km to evaluate the calibration *** filed experimental results show that for the Micro-electromechanical System

关键词： Acoustic LBL Online IMU calibration SINS Relay reference network

Learning the optimal power flow:Environment design matters

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Energy and AI 2024年第3期17卷 432-443页

作者： Thomas Wolgast Astrid nieße Carl von Ossietzky Universität Oldenburg Department of Computing ScienceDigitalized Energy SystemsAmmerländer Heerstraße 114-118Oldenburg26129Germany

To solve the optimal power flow(OPF)problem,reinforcement learning(RL)emerges as a promising new ***,the RL-OPF literature is strongly divided regarding the exact formulation of the OPF problem as an RL *** this work,we collect and implement diverse environment design decisions from the literature regarding training data,observation space,episode definition,and reward function *** an experimental analysis,we show the significant impact of these environment design options on RL-OPF training ***,we derive some first recommendations regarding the choice of these design *** created environment framework is fully open-source and can serve as a benchmark for future research in the RL-OPF field.

关键词： Reinforcement learning Optimal power flow Environment design Economic Dispatch Voltage control Reactive power market

Information Protocol Equilibrium in n-insider Perfect Competition with a Random Deadline

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Acta Mathematicae Applicatae Sinica 2024年

作者： Qi-hong nie Ji-xiu QIU Ji-ze LI Yong-hui ZHOU School of Big Data and Computer Sciences Guizhou Normal University School of Mathematical Sciences Guizhou Normal University

This paper studies a model of n insiders with perfect information trading on a risky asset with value normally distributed and disclosed at a random deadline. We propose a concept of information protocol equilibrium under semi-strong efficient pricing, consisting of an n-profile of insider trading strategies with terminal residual information protocols, and find that if a common protocol on terminal residual information before trading is obeyed by all insiders, then, in the market with more than two insiders there exists a uique equilibrium only when it requires to release common partial information eventually, or it does not exist if it requires to release all or not any; but in the market with a single insider, the insider may release all private information eventually to make a maximal profit. Thereby, the existence and uniqueness of information protocol equilibrium among n insiders are deduced. Finally, numerical results illustrate some market characteristics of equilibria with different information protocols required before trading.

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The Role of Childhood Circumstances in Healthy Aging Inequalities Among Older Adults—China,2011–2020

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China CDC weekly 2024年第11期6卷 208-212,I0004-I0007页

作者： Peng nie Xili Lin Lanlin Ding School of Economics and Finance Xi’an Jiaotong UniversityXi’an CityShaanxi ProvinceChina Global Health Institute Xi’an Jiaotong University Health Science CenterXi’an CityShaanxi ProvinceChina National School of Development Peking UniversityBeijingChina

What is already known about this topic?Addressing health disparities is a worldwide priority,with a well-established acknowledgment of the influence of childhood circumstances on these *** China,particularly among the elderly,health inequalities are a notable *** is added by this report?The inequality in healthy aging has increased from 2011 to 2020,both in general and concerning childhood ***,the impact of early-life healthcare access and parental health behaviors on healthy aging gaps has reduced among older adults in better health within the top segment of healthy *** are the implications for public health practice?Efforts towards reducing regional health disparities and improving healthcare access for children,along with promoting the health and well-being of parents,especially in economically disadvantaged households,are crucial policy considerations.

关键词： ledgment inequalities circumstances

Nitrite-driven anaerobic ethane oxidation

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Environmental Science and Ecotechnology 2024年第5期21卷 361-368页

作者： Cheng-Cheng Dang Yin-Zhu Jin Xin Tan Wen-Bo nie Yang Lu bing-Feng Liu De-Feng Xing Nan-Qi Ren Guo-Jun Xie State Key Laboratory of Urban Water Resource and Environment School of EnvironmentHarbin Institute of TechnologyHarbin150090China Key Laboratory of the Three Gorges Region's Eco-Environment Ministry of EducationCollege of Environment and EcologyChongqing UniversityChongqing400044China Water Innovation and Smart Environment Laboratory School of Civil and Environmental EngineeringFaculty of EngineeringQueensland University of TechnologyBrisbaneQueensland4001Australia

Ethane,the second most abundant gaseous hydrocarbon in vast anoxic environments,is an overlooked greenhouse *** anaerobic oxidation of ethane can be driven by available electron acceptors such as sulfate and ***,despite nitrite being a more thermodynamically feasible electron acceptor than sulfate or nitrate,little is known about nitrite-driven anaerobic ethane *** this study,a microbial culture capable of nitrite-driven anaerobic ethane oxidation was enriched through the long-term operation of a nitrite-and-ethane-fed *** continuous operation,the nitrite removal rate and the theoretical ethane oxidation rate remained stable at approximately 25.0 mg NO_(2) eN L^(-1) d^(-1) and 11.48 mg C2H6 L^(-1) d^(-1),*** tests demonstrated that ethane is essential for nitrite removal in this microbial *** function analysis revealed that a species affiliated with a novel genus within the family Rhodocyclaceae,designated as'Candidatus Alkanivoras nitrosoreducens',may perform the nitrite-driven anaerobic ethane *** the proposed metabolic model,despite the absence of known genes for ethane conversion to ethyl-succinate and succinate-CoA ligase,'***'encodes a prospective fumarate addition pathway for anaerobic ethane oxidation and a complete denitrification pathway for nitrite reduction to *** findings advance our understanding of nitrite-driven anaerobic ethane oxidation,highlighting the previously overlooked impact of anaerobic ethane oxidation in natural ecosystems.

关键词： Anaerobic ethane oxidation Denitrification Microbial culture Fumarate addition pathway Greenhouse gas