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聚氨酯/纳米SiO_(2)改性碳纤维增强环氧树脂复合材料界面性能

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复合材料学报 2023年第11期40卷 6073-6086页

作者：袁玉环左进霞彭聪武湛君大连理工大学材料科学与工程学院大连116024 大连理工大学工业装备结构分析国家重点实验室大连116024 大连理工大学人文与社会科学学院大连116024 江南大学纺织科学与工程学院无锡214000

聚合物与纤维之间的界面性能对提升复合材料力学性能尤为重要。本文采用异氰酸根(-NCO)封端的聚氨酯(PU)分子对纳米SiO_(2)表面进行改性,同时采用KH550对碳纤维(CF)进行表面改性,利用-NH2与-NCO较高的反应活性,在CF和纳米SiO_(2)粒子间... 详细信息

聚合物与纤维之间的界面性能对提升复合材料力学性能尤为重要。本文采用异氰酸根(-NCO)封端的聚氨酯(PU)分子对纳米SiO_(2)表面进行改性,同时采用KH550对碳纤维(CF)进行表面改性,利用-NH2与-NCO较高的反应活性,在CF和纳米SiO_(2)粒子间通过PU分子链形成共价键连接。结果显示:PU极性分子链的引入,提高了CF的表面能,使其表面润湿性显著提高。相较于KH550直接接枝纳米粒子的碳纤维(CF-KH550-SiO_(2)),通过PU分子链接枝纳米粒子的碳纤维(CF-KH550-PU-SiO_(2)),其表面能提升23.0%,表面纳米SiO_(2)粒子的接枝率和分散均匀性也明显提升。CF-KH550-PU-SiO_(2)/环氧树脂(EP)的界面剪切强度(IFSS)和层间剪切强度(ILSS)相比未改性CF/EP分别提高72.9%和47.9%,相比CF-KH550-SiO_(2)/EP分别提高17.3%和11.2%。

关键词：碳纤维增强环氧树脂复合材料界面性能纳米二氧化硅聚氨酯碳纤维表面改性

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畜牧业统计监测工作存在问题及建议

畜牧兽医科学（电子版） 2022年第10期 127-129页

作者：袁玉焕云南省南涧县无量山乌骨鸡产业发展服务中心云南南涧675700

畜牧业统计监测工作是畜牧业发展的“晴雨表”,事关畜牧业平稳、健康发展的大局,事关推进畜牧业高质量发展的大局,事关农业农村社会经济稳定的大局,该文就其现状、存在的问题和相应措施建议作简单探究性思考。

关键词：南涧县畜牧业统计监测工作现状问题建议

巯基功能化镁层状硅酸盐复合材料的构筑及其催化还原性能研究

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工业水处理 2023年第7期43卷 70-77页

作者：何贝贝袁玉环吕瑞绵阳师范学院化学与化学工程学院四川绵阳621000 西南科技大学环境与资源学院四川绵阳621010

通过原位合成法将银纳米粒子和Fe_(3)O_(4)磁性纳米粒子负载于巯基功能化镁层状硅酸盐(MgSH)上,制备得到Fe_(3)O_(4)@MgSH/Ag纳米复合材料。通过SEM、XRD、FTIR等手段对复合材料进行了表征,并考察了Fe_(3)O_(4)@MgSH/Ag催化NaBH4还原4-... 详细信息

通过原位合成法将银纳米粒子和Fe_(3)O_(4)磁性纳米粒子负载于巯基功能化镁层状硅酸盐(MgSH)上,制备得到Fe_(3)O_(4)@MgSH/Ag纳米复合材料。通过SEM、XRD、FTIR等手段对复合材料进行了表征,并考察了Fe_(3)O_(4)@MgSH/Ag催化NaBH4还原4-硝基苯酚(4-NP)的性能。研究结果表明,Fe_(3)O_(4)@MgSH/Ag保留了巯基黏土具有的疏松多孔结构,且银纳米粒子和Fe_(3)O_(4)纳米粒子均匀负载于MgSH表面。通过动力学分析可知,Fe_(3)O_(4)@MgSH/Ag催化NaBH_(4)还原4-NP的反应遵循准一级反应动力学规律,其表观速率常数kapp为0.1608 min^(-1),并可在10 min内使溶液中0.5 mmol/L 4-NP的降解率达到98%以上,说明Fe_(3)O_(4)@MgSH/Ag具有高效的催化性能。此外,由于Fe3O4的存在,该材料还可通过磁性回收利用,经过6次重复使用后,4-NP的降解率仅变化了6%,说明Fe_(3)O_(4)@MgSH/Ag在催化还原4-NP中显示出了高效性和可循环使用性。

关键词：巯基功能化镁层状硅酸盐 4-硝基苯酚催化还原

Collective Molecular Machines: Multidimensionality and Reconfigurability

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Nano-Micro Letters 2024年第8期16卷 309-340页

作者： Bin Wang yuan Lu Department of Chemical Engineering Tsinghua UniversityBeijing 100084People’s Republic of China Key Laboratory of Industrial Biocatalysis Ministry of EducationTsinghua UniversityBeijing 100084People’s Republic of China

Molecular machines are key to cellular activity where they are involved in converting chemical and light energy into efficient mechanical *** the last 60 years,designing molecular structures capable of generating unidirectional mechanical motion at the nanoscale has been the topic of intense *** progress has been made,attributed to advances in various fields such as supramolecular chemistry,biology and nanotechnology,and ***,individual molecular machines are only capable of producing nanometer work and generally have only a single *** order to address these problems,collective behaviors realized by integrating several or more of these individual mechanical units in space and time have become a new *** this review,we comprehensively discuss recent developments in the collective behaviors of molecular *** particular,collective behavior is divided into two *** is the appropriate integration of molecular machines to efficiently amplify molecular motions and deformations to construct novel functional *** other is the construction of swarming modes at the supramolecular level to perform nanoscale or microscale *** discuss design strategies for both modes and focus on the modulation of features and ***,in order to address existing challenges,the idea of transferring experience gained in the field of micro/nano robotics is presented,offering prospects for future developments in the collective behavior of molecular machines.

关键词： Molecular machines Collective control Collective behaviors DNA Biomolecular motors

MAUN:Memory-Augmented Deep Unfolding Network for Hyperspectral Image Reconstruction

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IEEE/CAA Journal of Automatica Sinica 2024年第5期11卷 1139-1150页

作者： Qian Hu Jiayi Ma yuan Gao Junjun Jiang Yixuan yuan Electronic Information School Wuhan UniversityWuhan 430072China School of Computer Science and Technology Harbin Institute of TechnologyHarbin 150001China Department of Electronic Engineering Chinese University of Hong KongHong Kong 999077China

Spectral compressive imaging has emerged as a powerful technique to collect the 3D spectral information as 2D *** algorithm for restoring the original 3D hyperspectral images(HSIs)from compressive measurements is pivotal in the imaging *** approaches painstakingly designed networks to directly map compressive measurements to HSIs,resulting in the lack of interpretability without exploiting the imaging *** some recent works have introduced the deep unfolding framework for explainable reconstruction,the performance of these methods is still limited by the weak information transmission between iterative *** this paper,we propose a Memory-Augmented deep Unfolding Network,termed MAUN,for explainable and accurate HSI ***,MAUN implements a novel CNN scheme to facilitate a better extrapolation step of the fast iterative shrinkage-thresholding algorithm,introducing an extra momentum incorporation step for each iteration to alleviate the information ***,to exploit the high correlation of intermediate images from neighboring iterations,we customize a cross-stage transformer(CSFormer)as the deep denoiser to simultaneously capture self-similarity from both in-stage and cross-stage features,which is the first attempt to model the long-distance dependencies between iteration *** experiments demonstrate that the proposed MAUN is superior to other state-of-the-art methods both visually and *** code is publicly available at https://***/HuQ1an/MAUN.

关键词： Deep folding iteration

Gradient microstructure and superior strength-ductility synergy of AZ61 magnesium alloy bars processed by radial forging with different deformation temperatures

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Journal of Materials Science & Technology 2024年第3期170卷 65-77页

作者： Jingfeng Zou Lifeng Ma Yanchun Zhu Ling Qin yuan yuan School of Mechanical Engineering Taiyuan University of Science and TechnologyTaiyuan 030024China Heavy Machinery Engineering Research Center of the Ministry Education Taiyuan University of Science and TechnologyTaiyuan 030024China Department of Engineering University of HullCottingham RdHull HU67RXUK National Engineering Research Center for Magnesium Alloys Chongqing UniversityChongqing 400044China

Gradient microstructure modification is a cost-efficient strategy for high strength without compromising ductility,which is urgently needed in the fundamental science of engineering *** this study,heterogeneous structures of AZ61 alloy bars with anisotropic gradients(with different grain size distributions from the surface to the center)were observed to exhibit strong strength-ductility synergies under different deformation tem *** results reveal that the grain refinement process under mediumlow temperature deformation conditions(≤350℃)consists of four transition stages along the radial direction,i.e.,twin activations and deformation band formations,dislocation cells and pile-ups,ultrafine sub-grains,and randomly orientated quasi-micron *** deformation temperatures have a great influence on twin activations and deformation band formations,and the high temperature can easily provoke the initiation of non-basal *** deformation bands were determined as a primary nucleation site due to their highly unstable dislocation hindrance *** in combination with the Radial forging(RF)deformation process,the differences of dynamic precipitates can be attributed to microstructural difference and solubility limit of Al at different tem *** summarizing the tensile test results,the sample forged at 350℃exhibited the best strength-ductility synergy,exhibiting the highest elongation(EL)of 23.2%with a 251 MPa yield strength(YS)and 394 MPa ultimate tensile strength(UTS)in center region,and combined with the highest strength value of 256 MPa YS and 420 MPa UTS in the center region,while the EL was slightly degraded to 19.8%.

关键词： Gradient microstructure Radial forging Strength-ductility synergy Magnesium alloy Strengthening mechanism

Pyrolysis Empirical Modeling of Polyester Glass Fiber Reinforced Plastics Using Sestak-Berggren Model Method

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Journal of Thermal Science 2024年第2期33卷 725-738页

作者： NAN Wei JI Wenhui yuan Yanping yuan Zhongyuan SUN Yong School of Mechanical Engineering Southwest Jiaotong UniversityChengdu610031China CRRC Changchun Railway Vehicles Co. LtdChangchun130062China

Polyester Glass Fiber Reinforced Plastic(Polyester GFRP),a thermosetting plastic comprised of glass fiber and polyester polymer compounds,is extensively utilized in high-speed *** its pyrolysis mechanism is crucial as it significantly influences the combustion characteristics and fire safety ***,kinetic research on polyester GFRP primarily focuses on employing the Coats-Redfern method to derive a theoretical kinetic ***,the pyrolysis process of polyester GFRP is complex and the aforementioned theoretical model fails to accurately describe the pyrolysis ***,this study seeks to utilize the Sestak and Berggren(SB) model as a methodological approach to reveal the complex reaction mechanism during the pyrolysis *** on thermogravimetric analysis,the entire pyrolysis process of polyester GFRP is divided into two primary ***,model-free methods are employed to ascertain the activation energy and pre-exponential *** results show that the fitted empirical models of the two main pyrolysis stages are f(α)=(1-α)^(1.47)[-ln(1-α)]^(1.50) and f(α)=(1-α)^(1.77)[-ln(1-α)]^(1.72),*** predicted results are in good agreement with experimental data under different heating rates,which indicates that the empirical model can sufficiently describe the pyrolysis process of polyester GFRP.

关键词： polyester GFRP model-fitting methods empirical models pyrolysis

Pseudomonotonicity of Nonlinear Transformations on Euclidean Jordan Algebras

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Acta Mathematicae Applicatae Sinica 2024年第1期40卷 192-204页

作者： yuan-Min Li School of Mathematics and Statistics Xidian UniversityXi’an710071China

In this paper, we have introduced the concepts of pseudomonotonicity properties for nonlinear transformations defined on Euclidean Jordan algebras. The implications between this property and other P-properties have been studied. More importantly, we have solved the solvability problem of the nonlinear pseudomonotone complementarity problems over symmetric cones.

关键词： Euclidean Jordan algebra nonlinear transformation complementarity problem pseudomonotone

Perspective of alkaline zinc-based flow batteries

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Science China Chemistry 2024年第1期67卷 260-275页

作者： Zhizhang yuan Xianfeng Li Division of Energy Storage Dalian National Laboratory for Clean Energy(DNL)Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 110623China

Energy storage technologies have been identified as the key in constructing new electric power systems and achieving carbon neutrality,as they can absorb and smooth the renewables-generated *** zinc-based flow batteries are well suitable for stationary energy storage applications,since they feature the advantages of high safety,high cell voltage and low ***,many alkaline zinc-based flow batteries have been proposed and developed,e.g.,the alkaline zinc–iron flow battery and alkaline zinc–nickel flow *** development and application are closely related to advanced materials and battery *** this perspective,we will first provide a brief introduction and discussion of alkaline zinc-based flow *** we focus on these batteries from the perspective of their current status,challenges and *** bottlenecks for these batteries are briefly *** with the practical requirements and development trends of alkaline zinc-based flow battery technologies,their future development and research direction will be summarized.

关键词： energy storage alkaline zinc-based flow batteries advanced materials battery structure