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The Constitutive Relation of a Fabric Membrane Composite for a Stratospheric Airship Envelope Based on Invariant Theory

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Computers, Materials & Continua 2017年第2期53卷 73-89页

作者： junhui Meng Mingyun Lv College of Engineering China Agricultural UniversityBeijing 100083PR China School of Aeronautic Science and Engineering Beihang UniversityBeijing 100191PR China.

The study of stratospheric airships has become the focus in many countries in recent years,because of its potential applications in many fields.Lightweight and high strength envelopes are the keys to the design of stratospheric airships,as it directly determines the endurance flight performance and loading deformation characteristics of the airship.A typical envelope of any stratospheric airship is a coated-fabric material which is composed of a fiber layer and several functional membrane layers.According to composite structure,nonlinearity and viscoelasticity are the two main characteristics of such envelope.Based on the analysis on the interaction between the different components in the micro-mechanical model of the coated-fabric,several invariant values reflecting the characteristics of the envelope material are obtained according to invariant theory.Furthermore,the constitutive equation that describes the viscoelasticity of the envelope material is derived.The constitutive equation can represent both the individual roles of the warp and weft fibers,and their further coupled interactions.The theoretical computation results were verified by off-axial tension tests.The results can help gain a deeper understanding of the mechanical mechanism and provide a reference for structural design of envelope material.

关键词： Stratospheric airship fabric membrane composite constitutive relation invariant theory viscoelasticity.

Surrogate-assisted optimization for anti-ship missile body configuration considering high-velocity water touching

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Chinese Journal of Aeronautics 2023年第12期36卷 268-281页

作者： Nianhui YE Teng LONG junhui Meng Renhe SHI Baoshou ZHANG School of Aerospace Engineering Beijing Institute of TechnologyBeijing 100081China Key Laboratory of Dynamics and Control of Flight Vehicle Ministry of EducationBeijing 100081China

As a crucial weapon in the sea battle,anti-ship missiles generally employ a sea-skimming penetration strategy to reduce the probability of being detected by the target radar,which greatly increases the risk of touching water caused by sensor errors or random sea conditions.To alleviate the large impact load by high-velocity water touching,a novel anti-ship missile body configuration is proposed in this paper,which is inspired by the idea of hydroplaning.A parametric geometry model is first developed to modify the configuration of the anti-ship missile body.Subsequently,a structured arbitrary Lagrange-Eulerian based Fluid-Structure Interaction(FSI)model is established to analyze the kinematics parameters of the missile body during the hydroplaning process.A missile body configuration optimization problem is then formulated to minimize the impact load considering several constraints,e.g.,horizontal velocity loss,pitch angle after touching water,and inside capacity for payload.Due to the time-consuming FSI simulation,a Kriging-assisted constrained differential evolution method is utilized to optimize the missile body configuration for reducing the impact load.During the optimization process,radial basis function and Kriging are combined with evolutionary operators to lead the search to the vicinity of the optimum rapidly.The result shows that the proposed missile body configuration can reduce the impact load by 18.8%compared with the ordinary configuration.Additionally,the optimized configuration can further yield a 17.4%impact load decrease subject to all the constraints and avoid structural damage by the high-velocity water touching,which demonstrates the effectiveness and practicability of the proposed anti-ship missile body configuration and corresponding optimization framework for reducing the impact load.

关键词： Surrogate-assisted optimiza-tion Fluid-structureinteraction Arbitrary Lagrange-Eulerian Missile Conceptual design

Tectonics of the Solomon Sea Basin from Vertical Gravity Gradient and Seismic Data

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Acta Geologica Sinica(English Edition) 2023年第2期97卷 610-622页

作者： GONG Wei XING junhui meng Qingwei XING Lei XU Chong ZHANG Hao Key Laboratory of Submarine Geosciences and Prospecting Techniques Ministry of Educationand College of Marine GeosciencesOcean University of ChinaQingdaoShandong 266100China Laboratory for Marine Mineral Resources Qingdao National Laboratory for Marine Science and TechnologyQingdaoShandong 266237China Chinese Academy of Geological Sciences Beijing 100037China

The Solomon Sea Basin is a Cenozoic back-arc spreading basin within the convergence system of the Pacific and Indo-Australian plates.Against the background of subduction polarity reversal,the current Solomon Sea Basin gradually formed a rhombic morphology with the subduction of the basin along the New Britain Trench and the Trobriand Trough.By analyzing the vertical gravity gradient,natural earthquake and seismic reflection data,this study determines the structural characteristics of the Solomon Sea Basin.It was found that the tectonics of the basin are characterized by the original expansion structure within the central part in addition to the structure induced by the latest subduction along the basin margin.The original spreading structure of the basin presented an east–west linear graben and horst controlled by normal faults during the basin expansion period.As a result of the subduction and slab-pull of the Solomon Sea Basin,extensional structure belts parallel to the New Britain Trench formed along the basin margin.

关键词： vertical gravity gradient seismic data tectonics New Britain Trench Solomon Sea Basin

Genomic prediction using composite training sets is an effective method for exploiting germplasm conserved in rice gene banks

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The Crop Journal 2022年第4期10卷 1073-1082页

作者： Sang He Hongyan Liu junhui Zhan Yun meng Yamei Wang Feng Wang Guoyou Ye CAAS-IRRI Joint Laboratory for Genomics-Assisted Germplasm Enhancement Agricultural Genomics Institute in ShenzhenChinese Academy of Agricultural SciencesShenzhen 518120GuangdongChina Rice Breeding Innovations Platform International Rice Research InstituteDAPO Box 7777Metro ManilaPhilippines Guangdong Provincial Key Laboratory of New Technology in Rice Breeding Rice Research InstituteGuangdong Academy of Agricultural SciencesGuangzhou 510640GuangdongChina Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresource College of Tropical CropsHainan UniversityHaikou 570228HainanChina

Germplasm conserved in gene banks is underutilized,owing mainly to the cost of characterization.Genomic prediction can be applied to predict the genetic merit of germplasm.Germplasm utilization could be greatly accelerated if prediction accuracy were sufficiently high with a training population of practical size.Large-scale resequencing projects in rice have generated high quality genome-wide variation information for many diverse accessions,making it possible to investigate the potential of genomic prediction in rice germplasm management and exploitation.We phenotyped six traits in nearly 2000 indica(XI)and japonica(GJ)accessions from the Rice 3K project and investigated different scenarios for forming training populations.A composite core training set was considered in two levels which targets used for prediction of subpopulations within subspecies or prediction across subspecies.Composite training sets incorporating 400 or 200 accessions from either subpopulation of XI or GJ showed satisfactory prediction accuracy.A composite training set of 600 XI and GJ accessions showed sufficiently high prediction accuracy for both XI and GJ subspecies.Comparable or even higher prediction accuracy was observed for the composite training set than for the corresponding homogeneous training sets comprising accessions only of specific subpopulations of XI or GJ(within-subspecies level)or pure XI or GJ accessions(across-subspecies level)that were included in the composite training set.Validation using an independent population of 281 rice cultivars supported the predictive ability of the composite training set.Reliability,which reflects the robustness of a training set,was markedly higher for the composite training set than for the corresponding homogeneous training sets.A core training set formed from diverse accessions could accurately predict the genetic merit of rice germplasm.

关键词： Genomic prediction Composite training set Rice germplasm Gene bank Reliability criterion

Polymer Electron Acceptors Based on Fluorinated Isoindigo Unit for Polymer Solar Cells

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Chinese Journal of Chemistry 2018年第5期36卷 411-416页

作者： junhui Miao Hall Xu Bin meng Jun Liu Lixiang Wang State Key Laboratory of Polymer Physics and Chemistry Changchun Institute of Applied Chemistry Chinese Academy of Sciences Chang- chun Jijin 130022 China University of Science and Technology of China Hefei Anhui 230026 China Center for Advanced Optoelectronic Functional Materials Research Northeast Normal University Changchun Jilin 130024 China

Most of efficient polymer electron acceptors for polymer solar cells （PSCs） are based on naphthalene diimide or perylene diimide as the electron deficient building block. In this paper, for the first time, we report polymer electron acceptors based on fluorinated isoindigo IF-lID） as the electron deficient building block. We synthesized two polymer electron acceptors consisting of alternating F-lID unit and thiophene/selenophen unit, They show low-lying LUMo/HOMO energy levels of-3.69/-5.69 eV, high electron mobilities of 1.31 ×10-5 cm2.V-1s-1 and broad absorption spectra with the optical bandgap of 1.61 eV. PSC devices using the two F-liD-based polymers as polymer electron acceptors show encouraging power conversion efficiencies （PCEs） of up to 1.50% with an open-circuit voltage （Voc） of 0.97V, a short-circuit current density （Jsc） of 2.91 mA.cm2, and a fill factor （FF） of 53.2%. This work suggests a new kind of polymer electron acceptors based on F-IID unit.

关键词： polymer solar cells polymer electron acceptor fluorinated isoindigo n-type conjugated polymer

Synthetic strategy of biomimetic sea urchin-like Co-NC@PANI modified MXene-based magnetic aerogels with enhanced electromagnetic wave absorption properties

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Nano Research 2024年第3期17卷 2025-2037页

作者： meng Yu Ying Huang Xudong Liu Kaihang She Xiaoxiao Zhao Wanqing Fan Xiaofang Ma junhui Zou Tiehu Li MOE Key Laboratory of Material Physics and Chemistry Under Extraordinary Conditions School of Chemistry and Chemical EngineeringNorthwestern Polytechnical UniversityXi’an 710129China NPU-NCP Joint International Research Center on Advanced Nanomaterials&Defects Engineering State Key Laboratory of Solidification ProcessingShaanxi Engineering Laboratory for Graphene New Carbon Materials and ApplicationsSchool of Materials Science and EngineeringNorthwestern Polytechnical UniversityXi’an 710072China

The rational and effective combination of multicomponent materials and ingenious microstructure design for efficient electromagnetic wave(EMW)absorption are still challenging.In this paper,MXene was used as the aerogel matrix,modified with sea urchin-like magnetic Co/N-doped carbon@polyaniline(Co-NC@PANI),gelatin was introduced as the reinforcement phase of the aerogel backbone,and a microwave absorber with high efficiency and excellent performance was successfully prepared.The sea urchin-like Co-NC@PANI not only adjusted the impedance matching of the MXene but also introduced a magnetic loss mode into the composite.The multicomponent interfacial polarization,heterostructure,three-dimensional(3D)lightweight porous structure,and electromagnetic synergy strategy enabled the MXene-based aerogel modified by Co-NC@PANI(MCoP)to exhibit surprising EMW absorption properties.The maximum reflection loss(RL_(max))of the aerogel composite reached-62.4 dB,and the effective absorption bandwidth(EAB)reached 6.56 GHz when the loading was only 12%.In addition,through electromagnetic simulation experiments,the change in the electromagnetic field before and after EMW passed through the materials and the distribution of the volume loss density of EMW by the coaxial ring were observed.The coordinated electromagnetic balance strategy in the 3D network provides inspiration for the construction of materials and expands the research direction of lightweight and outstanding microwave absorbers.

关键词： MXene sea urchin-like Co/N-doped carbon@polyaniline(Co-NC@PANI) aerogel electromagnetic synergy strategy electromagnetic wave absorption

Rational construction of high-active CO_(3)O_(4) electrocatalysts for oxygen evolution reaction

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Nano Research 2023年第1期16卷 624-633页

作者： Tianyun Zhang Shichao Zhao Chuanming Zhu Jing Shi Chao Su Jiawen Yang meng Wang Jun Li junhui Li Pingle Liu Conghui Wang College of Chemical Engineering Xiangtan UniversityXiangtan 411105China State Key Laboratory of Coal Conversion Institute of Coal ChemistryChinese Academy of SciencesTaiyuan 030001China Analytical Instrumentation center Institute of Coal ChemistryChinese Academy of SciencesTaiyuan 030001China

Rational construction of high-efficiency electrocatalysts for oxygen evolution reaction(OER)is critical for renewable-energy technologies,but it is highly challenging to rationally regulate their surface structures to improve the OER performance.Herein,we proposed a“model-etching”strategy to investigate chemical etching of CO_(3)O_(4).The cubic CO_(3)O_(4)nanocrystals enclosed by well-defined facets are synthesized as model crystals,whose uniform surface structures allow us to study the etching mechanism at atomic level.Etching kinetics study together with DFT calculations discloses that{111}facets,the highly active facets for OER,serve as etch-stop facets in the etching reaction and H_(2)SO_(4)molecules play a special role in creating surface Co2^(+),the active center of OER.These results direct us to rationally optimize the surface structures of CO_(3)O_(4) to develop highly active OER electrocatalysts.The favorable performance of overpotential(η)and the Tafel slope decrease even to 268 mV@10 mA·cm−2 and 74 mV·dec−1,respectively.In general,our study shows that chemical etching of model crystals could help us rationally construct high-efficiency electrocatalysts.

关键词： cobalt oxide chemical etching high active facets oxygen evolution reaction surface structure

Multi-Object Tracking Based on Segmentation and Collision Avoidance

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Journal of Beijing Institute of Technology 2018年第2期27卷 213-219页

作者： meng Zhao junhui Wang Maoyong Cao Peirui Bai Hongyan Gu Mingtao Pei College of Electrical Engineering and Automation Shandong University of Science and Technology College of Electronic Communication and PhysicsShandong University of Science and Technology Beijing Lab of Intelligent Information Technology Beijing Institute of Technology

An approach to track multiple objects in crowded scenes with long-term partial occlusions is proposed. Tracking-by-detection is a successful strategy to address the task of tracking multiple objects in unconstrained scenarios,but an obvious shortcoming of this method is that most information available in image sequences is simply ignored due to thresholding weak detection responses and applying non-maximum suppression. This paper proposes a multi-label conditional random field（ CRF） model which integrates the superpixel information and detection responses into a unified energy optimization framework to handle the task of tracking multiple targets. A key characteristic of the model is that the pairwise potential is constructed to enforce collision avoidance between objects,which can offer the advantage to improve the tracking performance in crowded scenes. Experiments on standard benchmark databases demonstrate that the proposed algorithm significantly outperforms the state-of-the-art tracking-by-detection methods.

关键词： multi-object tracking conditional random field superpixel collision avoidance

急性Stanford A型主动脉夹层手术患者术中局部脑氧饱和度和神经损伤标记物与术后神经功能障碍的相关性

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中华胸心血管外科杂志 2023年第1期39卷 26-31页

作者：周俊辉高洁孟宪慧河南省胸科医院麻醉科郑州450008 中国医学科学院阜外医院麻醉科北京100037

目的探讨急性Stanford A型主动脉夹层手术患者术中局部脑氧饱和度(rScO_(2))和神经损伤标记物与术后神经功能障碍(PND)的相关性。方法选取2020年7月至2021年5月于河南省胸科医院手术室急诊行体外循环(CPB)下Stanford A型主动脉夹层手术... 详细信息

目的探讨急性Stanford A型主动脉夹层手术患者术中局部脑氧饱和度(rScO_(2))和神经损伤标记物与术后神经功能障碍(PND)的相关性。方法选取2020年7月至2021年5月于河南省胸科医院手术室急诊行体外循环(CPB)下Stanford A型主动脉夹层手术的患者57例, 性别不限, 年龄35~64岁, 体质量58.0~90.0 kg, 美国麻醉医师协会(ASA)分级Ⅱ-Ⅲ级。术中以近红外光谱仪(NIRS)连续监测患者双侧rScO_(2)。分别于麻醉诱导前10 min(T0)、麻醉诱导后10 min(T1)、CPB开始即刻(T2)、CPB结束时(T3)、术毕(T4)、转出ICU时(T5)、术后1天(T6)、2天(T7)和3天(T8)抽取中心静脉血并测定血清中神经损伤标志物特异性蛋白100β(S100β蛋白)和神经元特异性烯醇化酶(neuron specific enolase, NSE)浓度。术后3天随访, 评估PND的发生情况, 比较PND组和无PND (NPND)组患者术中rScO_(2)值和血清S100β蛋白及NSE浓度的变化, 分析PND发生的危险因素及其与术中rScO_(2)和血清S100β蛋白和NSE浓度的相关性。统计并分析两组患者预后的相关指标。结果 3例患者因术后接受二次手术、二次气管内插管和ECMO(各1例)被剔除出该研究。术后3天12例(22.2%)发生PND(PND组), 42例(77.8%)未发生PND(NPND组)。与NPND组比较, PND组患者CPB中平均动脉压最小值、CPB中rScO_(2)最小值明显降低(P25%持续时间、CPB中rScO_(2)0.50持续时间、CPB中da-rScO_(2)>0.40持续时间均明显延长(P25%持续时间(P=0.033)、CPB过程中rScO_(2)0.50持续时间(P=0.001)是发生PND的危险因素。与NPND组比较, PND组患者术后机械通气、ICU滞留、术后住院天数和PND恢复时间均显著延长(P25%持续时间、rScO_(2)0.50持续时间是CPB下急性Stanford A型主动脉夹层手术患者发生PND的危险因素。血清S100β蛋白和NSE水平的显著升高与PND的发生有关。PND的发生对患者早期临床预后产生显著的不良影响。

关键词：体外循环术后神经功能障碍脑氧饱和度急性Stanford A型主动脉夹层神经损伤标记物神经系统并发症