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Deployment analysis of composite thin-walled lenticular tubes with effect of storage time and temperature

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Chinese Journal of Aeronautics 2024年第1期37卷 162-172页

作者： Jinfeng DENG Ning AN Qilong jia Xiaofei ma School of Aeronautics and Astronautics Sichuan UniversityChengdu 610065China State Key Laboratory for Strength and Vibration of Mechanical Structures School of AerospaceXi’an Jiaotong UniversityXi’an 710049China State Key Laboratory of Structural Analysis for Industrial Equipment Dalian University of TechnologyDalian 116024China Xi’an Institute of Space Radio Technology Xi’an 710100China

Composite Thin-walled lenticular Tube(CTLT)is increasingly utilized in small satellites missions as a lightweight,foldable,and rollable structural material that facilitates the construction of large deployable *** CTLT is initially flattened and coiled around a central hub for storage before launch,during which elastic energy is stored as deformation energy,allowing it to be self-deployed on demand for use in *** work presents a comprehensive investigation into the coiling,storage and deployment behaviors of CTLT that wraps around a central hub.A nonlinear explicit dynamic finite element model was developed with both deformable CTLT and rigidbodies mechanisms including the central hub and guide rollers,as well as the complex interactions among *** coiling mechanics characteristics such as stored strain energy and rotational moment were presented and validated against experimental data in the ***,the dynamic deployment behaviors were analyzed in terms of two different deployment methods,namely,controlled deployment and free *** effect of material property change during storage was also discussed through numerical experiments.

关键词： Composite deployable structures Deployment dynamics Finite element method Stress relaxation Thin-walled booms

Accurate Analysis of Multi-Mode Interferometric Optical Fiber Sensor

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Photonic Sensors 2024年第1期14卷 48-58页

作者： Lijun LI Congying jia Qian ma Tianzong XU College of Electronic and Information Engineering Shandong University of Science and TechnologyQingdao 266590.China State Key Laboratory of Mining Disaster Prevention and Control Co-Founded by Shandong Province and the Ministry of Science and Technology Qingdao 266590China

In view of the problem that the sensing characteristics of the multi-mode interferometric fiber sensors cannot be accurately analyzed,an analysis method based on the fast Fourier transform(FFT)and inverse fast Fourier transform(IFFT)is proposed and demonstrated theoretically and *** suitabilities of the rectangular window function with the narrow main lobe(high spectrum resolution)and low side lobe(high main mode energy leakage)and the Hanning window function with the wide main lobe(low spectrum resolution)and high side lobe(high energy concentration)in this kind of sensor analysis are discussed,*** method can not only realize the sensing performance analysis of the various modes,but also overcome the inconsistency of the different interference wavelength(dip)sensing characteristics in the conventional analysis *** the same time,this method is also beneficial to solve the repetitive problem of such sensors.

关键词： Window function FFT optical fiber interferometric sensor analysis method

Requirements ranking based on crowd-sourcing high-end product USs

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Journal of Systems Engineering and Electronics 2024年第1期35卷 94-104页

作者： ma Yufeng DOU Yajie XU Xiangqian jia Qingyang TAN Yuejin College of Systems Engineering National University of Defense TechnologyChangsha 410003China

Based on the characteristics of high-end products,crowd-sourcing user stories can be seen as an effective means of gathering requirements,involving a large user base and generating a substantial amount of unstructured *** key challenge lies in transforming abstract user needs into specific ones,requiring integration and ***,we propose a topic mining-based approach to categorize,summarize,and rank product requirements from user ***,after determining the number of story categories based on py LDAvis,we initially classify“I want to”phrases within user ***,classic topic models are applied to each category to generate their names,defining each post-classification user story category as a ***,a weighted ranking function is devised to calculate the importance of each ***,we validate the effectiveness and feasibility of the proposed method using 2966 crowd-sourced user stories related to smart home systems.

关键词： high-end product complex system crowd-sourcing user stories topic mining requirements ranking

Experimental investigation on weak shock wave mitigation characteristics of flexible polyurethane foam and polyurea

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Defence Technology（防务技术） 2024年第1期31卷 179-191页

作者： Shiyu jia Cheng Wang Wenlong Xu Dong ma Fangfang Qi State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing100081China Institute for Advanced Technology Shandong UniversityJinan250061China

In recent years,explosion shock wave has been considered as a signature injury of the current military *** strong shock wave is lethal to the human body,weak shock wave can cause many more lasting *** investigate the protection ability and characteristics of flexible materials and structures under weak shock wave loading,the blast wave produced by TNT explosive is loaded on the polyurethane foam with the density of 200.0 kg/m3(F-200)and 400.0 kg/m3(F-400),polyurea with the density of 1100.0 kg/m^(3)(P-1100)and structures composed of the two materials,which are intended for individual *** results indicate that the shock wave is attenuated to weak pressure disturbance after interacting with the flexible materials which are not *** shock wave protective capability of single-layer materials is dependent on their thickness,density and microscopic *** overpressure,maximum pressure rise rate and impulse of transmitted wave decrease exponentially with increase in sample *** the same thickness,F-400 provides better protective capability than F-200 while P-1100 shows the best protective capability among the three *** this study,as the materials are not destroyed,F-200 with a thickness more than10.0 mm,F-400 with a thickness more than 4.0 mm,and P-1100 with a thickness more than 1.0 mm can attenuate the overpressure amplitude more than 90.0%.Further,multi-layer flexible composites are *** layer layouts of designed structures and layer thickness of the single-layer materials can affect the protective *** the research range,the structure in which polyurea is placed on the impact side shows the optimal shock wave protective performance,and the thicknesses of polyurea and polyurethane foam are 1.0 mm and 4.0 mm *** overpressure attenuation rate reached maximum value of 93.3%and impulse attenuation capacity of this structure are better than those of s

关键词： Free-field explosion Weak shock wave mitigation Polyurea Polyurethane foam Multi-layered composites

PAPS: Progressive Attention-Based Pan-sharpening

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IEEE/CAA Journal of Automatica Sinica 2024年第2期11卷 391-404页

作者： Yanan jia Qiming Hu Renwei Dian jiayi ma Xiaojie Guo College of Intelligence and Computing Tianjin UniversityTianjin 300350 China IEEE School of Robotics Hunan UniversityChangsha 410082China Electronic Information School Wuhan UniversityWuhan 430072China

Pan-sharpening aims to seek high-resolution multispectral(HRMS) images from paired multispectral images of low resolution(LRMS) and panchromatic(PAN) images, the key to which is how to maximally integrate spatial and spectral information from PAN and LRMS images. Following the principle of gradual advance, this paper designs a novel network that contains two main logical functions, i.e., detail enhancement and progressive fusion, to solve the problem. More specifically, the detail enhancement module attempts to produce enhanced MS results with the same spatial sizes as corresponding PAN images, which are of higher quality than directly up-sampling LRMS *** a better MS base(enhanced MS) and its PAN, we progressively extract information from the PAN and enhanced MS images, expecting to capture pivotal and complementary information of the two modalities for the purpose of constructing the desired HRMS. Extensive experiments together with ablation studies on widely-used datasets are provided to verify the efficacy of our design, and demonstrate its superiority over other state-of-the-art methods both quantitatively and qualitatively. Our code has been released at https://***/jiaYN1/PAPS.

关键词： High-resolution multispectral image image fusion pan-sharpening progressive enhancement

The Forecast Skills and Predictability Sources of marine Heatwaves in the NUIST-CFS1.0 Hindcasts

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Advances in Atmospheric Sciences 2024年第8期41卷 1589-1600页

作者： Jing ma Haiming XU Changming DONG Jing-jia LUO Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters/KLME/ILCEC/Institute of Climate and Application Research(ICAR) Nanjing University of Information Science and TechnologyNanjingJiangsu 210044China

Using monthly observations and ensemble hindcasts of the Nanjing University of Information Science and Technology Climate Forecast System(NUIST-CFS1.0) for the period 1983–2020, this study investigates the forecast skill of marine heatwaves(MHWs) over the globe and the predictability sources of the MHWs over the tropical oceans. The MHW forecasts are demonstrated to be skillful on seasonal-annual time scales, particularly in tropical oceans. The forecast skill of the MHWs over the tropical Pacific Ocean(TPO) remains high at lead times of 1–24 months, indicating a forecast better than random chance for up to two years. The forecast skill is subject to the spring predictability barrier of El Nino-Southern Oscillation(ENSO). The forecast skills for the MHWs over the tropical Indian Ocean(TIO), tropical Atlantic Ocean(TAO), and tropical Northwest Pacific(NWP) are lower than that in the TPO. A reliable forecast at lead times of up to two years is shown over the TIO, while a shorter reliable forecast window(less than 17 months) occurs for the TAO and ***, the forecast skills for the TIO, TAO, and NWP are seasonally dependent. Higher skills for the TIO and TAO appear in boreal spring, while a greater skill for the NWP emerges in late summer-early autumn. Further analyses suggest that ENSO serves as a critical source of predictability for MHWs over the TIO and TAO in spring and MHWs over the NWP in summer.

关键词： marine heatwaves NUIST-CFS1.0 hindcasts forecast skill predictability source ENSO

Cross-linkedα-amylase aggregates on Fe3O4 magnetic nanoparticles modified with polydopamine/polyethyleneimine for efficient hydrolysis of starch

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Particuology 2024年第7期90卷 98-105页

作者： jiandong Cui Xiuming Tang Qingqing ma Yuyan Chang Qunli Zhang Shiru jia State Key Laboratory of Food Nutrition and Safety Laboratory of Industrial Fermentation MicrobiologyMinistry of EducationTianjin University of Science and TechnologyTianjin 300457China Key Laboratory of Biomass Chemical Engineering of Ministry of Education Zhejiang UniversityHangzhou 310027China

In this workα-amylase was immobilized on magnetic Fe3O4 nanoparticles with polyethylenimine(PEI)/polydopamine(PDA)coating or 3-aminopropyl triethoxysilane(APTES)for the first time via adsorption–precipitation–*** with the freeα-amylase,the resultant magnetic cross-linkedα-amylase aggregates(PEI/PDA-M-CleAs and N-M-CleAs)exhibited excellent thermal and storage stability as well as pH *** storage at 25°C for 60 days,freeα-amylase only retained 60%of its initial activity,while PEI/PDA-M-CleAs and N-M-CleAs retained 80%and 78%of their initial activities,***,N-M-CleAs and PEI/PDA-M-CleAs showed good *** 6 repeated uses,PEI/PDA-M-CleAs and N-M-CleAs still maintained 65%and 62%of their initial activities,***,PEI/PDA-M-CleAs and N-M-CleAs exhibited higher starch hydrolysis efficiency than freeα-*** maximum dextrose equivalent(DE)values of starch hydrolysis by PEI/PDA-M-CleAs and N-M-CleAs reached 29.24%and 28.79%within 90 min,***,the maximum DE values of starch hydrolysis by the freeα-amylase was only 27.89%even in 150 *** magnetic cross-linkedα-amylase aggregates could be introduced as effective biocatalyst for industrial applications in production of maltose syrups.

关键词： α-amylase magnetic nanoparticles Functional modification magnetic cross-linked enzyme aggregates Hydrolysis of starch

Synthesis,Characterization of Polyethylene Ionomers and Their Antibacterial Properties

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Chinese Journal of Polymer Science 2024年第8期42卷 1077-1084页

作者： jia-jia Wu Fei Wang Peng-Qi Wan Li Pan Chun-Sheng Xiao Zhe ma Yue-Sheng Li Tianjin Key Lab Composite&Functional materials School of Materials Science and EngineeringTianjin UniversityTianjin 300350China Key Lab Polymer Ecomaterials Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China

Owing to its high production volume and wide range of application s,polyethylene has gained a great deal of attention,but its low surface energy and non-polar nature have limited its application in some important *** this study,ethylene/11-iodo-1-undecene copolymers were prepared and used as the intermediates to afford a series of imidazolium-based ionomers bearing methanesulfonate(CH_(3)SO_(3)^(-)),trifluoromethanesulfonate(CF_(3)SO_(3)^(-)),or bis(trifluoromethane)sulfonimide(Tf_(2)N^(-))*** tensile test results showed that the stress-at-break(7.8-25.6 MPa)and the elongation-at-break(445%-847%)of the ionomers could be adjusted by changing the counterion species and the ionic group *** importantly,the ionomers exhibited marvelous antibacterial activities against Staphylococcus aureus(***)and Escherichia coli(***).The ionomers bearing Tf_(2)N^(-)exhibited antibacterial activities>99%against both *** and *** when ionic content reached 9.1%.The imidazolium-based ionomers prepared in this work demonstrated excellent comprehensive properties,especially highefficient and broad-spectrum antibacterial ability,exhibiting the potential fo r the application as the antibacterial materials in packaging,medical,and other fields.

关键词： Polyethylene Ionomer Polymerization catalysis Imidazolium Antibacterial material

Characteristics and Influencing Factors of Microplastics in Snow in the Inner Mongolia Plateau, China

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Engineering 2024年第6期37卷 69-77页

作者： Hongwei Yu Junrong Shao Huawei jia Diga Gang Baiwen ma Chengzhi Hu State Key Laboratory of Environmental Aquatic Chemistry Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China University of Chinese Academy of Sciences Beijing 100049China Changjiang Survey PlanningDesign and Research Co.Ltd.Wuhan 430010China

Microplastics(MPs;<5 mm)have become one of the most prominent global environmental pollution *** can spread to high altitudes through atmospheric transport and can be deposited by rainfall or snowfall,potentially thre... 详细信息

Microplastics(MPs;le attention has been given to the possible harm associated with MPs deposited in snow,particularly in the context of global climate *** collected from surface snow in the Inner Mongolia Plateau,China,were used for quantitative analysis and *** results showed that MPs were easily detected,and the related concentration was approximately(68±10)–(199±22)MPsL1 in snow *** were the most common morphology,the polymer composition was largely varied,and the abundance and composition of MPs were linked to human activity to a great ***-throughput sequencing results showed that the composition and abundance of microorganisms also differed in snow samples from areas with different MP pollution characteristics,indicating a considerable difference in microbial functional *** may have an interference effect on the individual growth and functional expression of microorganisms in *** addition,the results showed that functional living areas(e.g.,landfills and suburban areas)in cities play an important role in the properties of *** instance,the highest abundance of MPs was found in thermal power plants,whereas the abundance of polymers per sample was significantly lower in the suburban *** MP contaminants hidden in snow can alter microbial structure and function and are therefore a potential threat to ecosystem health.

关键词： Human activities Snow Microplastics Microbial community Urban function Environmental effect