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Toward tunable shape memory effect of NiTi alloy by grain size engineering:A phase field study

Journal of Materials Science & Technology 2024年第1期168卷 276-289页

作者： Bo Xu Chong wang Qingyuan wang Failure Mechanics and Engineering Disaster Prevention Key Laboratory of Sichuan ProvinceSichuan UniversityChengdu 610065China Department of Mechanical Science and Engineering College of Architecture and EnvironmentSichuan UniversityChengdu 610065China Key Laboratory of Deep Underground Science and Engineering (Sichuan University)Ministry of EducationChengdu 610065China

The inelastic deformations of shape memory alloys(SMAs)always show poor controllability due to the avalanche-like martensite transformation,and the effective control for the deformation of precision de-vices has been not yet *** this work,the phase field method was used to investigate the shape memory effects(SMEs)of NiTi SMAs undergoing grain size(GS)engineering,to obtain tunable one-way and stress-assisted two-way SMEs(OWSME and SATWSME).The OWSME and SATWSME of the systems with various gradient-nanograin structures and bimodal grain structure,as well as that with geometric gradients were *** simulated results indicate that due to the GS dependences of martensite transformation and reorientation,the occurrence and expansion of martensite reorientation,martensite transformation and its reverse can be efficaciously controlled via the GS *** combining the GS engineering and geometric gradient design,since the effects of GS and stress gradient can be su-perimposed or competing,and the responses of martensite reorientation,martensite transformation and its reverse to this are different,the OWSME and SATWSME of the geometrically graded systems with various nanograin structures can exhibit different improvements in *** short,the reorienta-tion hardening modulus during OWSME is increased and the transformation temperature window during SATWSME is widened by GS engineering,indicating the improved controllability of *** optimal GS engineering schemes revealed in this work provide the basic reference and guidance for designing tun-able SMEs and producing NiTi-based driving devices catering to desired functional performance in various engineering fields.

关键词： Phase field NiTi Shape memory effect Grain size engineering Geometric gradient

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A novel triple periodic minimal surface-like plate lattice and its data-driven optimization method for superior mechanical properties

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Applied Mathematics and Mechanics(English Edition) 2024年第2期45卷 217-238页

作者： Yanda wang Yanping LIAN Zhidong wang Chunpeng wang Daining FANG State Key Laboratory for Turbulence and Complex Systems&Center for Applied Physics and Technology College of EngineeringPeking UniversityBeijing 100871China Institute of Advanced Structure Technology Beijing Institute of TechnologyBeijing 100081China

Lattice structures can be designed to achieve unique mechanical properties and have attracted increasing attention for applications in high-end industrial equipment,along with the advances in additive manufacturing(AM)*** this work,a novel design of plate lattice structures described by a parametric model is proposed to enrich the design space of plate lattice structures with high connectivity suitable for AM *** parametric model takes the basic unit of the triple periodic minimal surface(TPMS)lattice as a skeleton and adopts a set of generation parameters to determine the plate lattice structure with different topologies,which takes the advantages of both plate lattices for superior specific mechanical properties and TPMS lattices for high connectivity,and therefore is referred to as a TPMS-like plate lattice(TLPL).Furthermore,a data-driven shape optimization method is proposed to optimize the TLPL structure for maximum mechanical properties with or without the isotropic *** this method,the genetic algorithm for the optimization is utilized for global search capability,and an artificial neural network(ANN)model for individual fitness estimation is integrated for high efficiency.A set of optimized TLPLs at different relative densities are experimentally validated by the selective laser melting(SLM)fabricated *** is confirmed that the optimized TLPLs could achieve elastic isotropy and have superior stiffness over other isotropic lattice structures.

关键词： lattice structure triple periodic minimal surface(TPMS) plate lattice structural optimization machine learning

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Adaptive Barrier-Lyapunov-Functions Based Control Scheme of Nonlinear Pure-Feedback Systems with Full State Constraints and Asymptotic Tracking Performance

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Journal of Systems Science & Complexity 2024年第3期37卷 965-984页

作者： NIU Ben wang Xiaoan wang Xiaomei wang Xinjun LI Tao Faculty of Electronic Information and Electrical Engineering Dalian University of TechnologyDalian 116024China School of Information Science and Engineering Shandong Normal UniversityJinan 250014China School of Mathematics Southeast UniversityNanjing 211189China School of Automation Nanjing University of Information Science and TechnologyNanjing 210044China

In this paper,the authors propose an adaptive Barrier-Lyapunov-Functions(BLFs)based control scheme for nonlinear pure-feedback systems with full state *** to the coexist of the non-affine structure and full state constraints,it is very difficult to construct a desired controller for the considered *** to the mean value theorem,the authors transform the pure-feedback system into a system with strict-feedback structure,so that the well-known backstepping method can be ***,in the backstepping design process,the BLFs are employed to avoid the violation of the state constraints,and neural networks(NNs)are directly used to online approximate the unknown packaged nonlinear *** presented controller ensures that all the signals in the closed-loop system are bounded and the tracking error asymptotically converges to ***,it is shown that the constraint requirement on the system will not be violated during the ***,two simulation examples are provided to show the effectiveness of the proposed control scheme.

关键词： Asymptotic tracking control barrier Lyapunov functions full state constraints nonlinear pure-feedback systems

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The Coarse l^(p)-Novikov Conjecture and Banach Spaces with Property(H)

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Chinese Annals of Mathematics,Series B 2024年第2期45卷 193-220页

作者： Huan wang Qin wang Research Center for Operator Algebras School of Mathematical SciencesEast China Normal UniversityShanghai 200241China Key Laboratory of MEA Ministry of Educationand Shanghai Key Laboratory of PMMPEast China Normal UniversityShanghai 200241China

In this paper,for 1

关键词： The coarse l^(p)-Novikov conjecture Banach spaces with Property(H) Coarse geometry K-Theory

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基于时空数据融合的县域水稻种植面积提取

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农业机械学报 2020年第4期51卷 156-163页

作者：牛海鹏王占奇肖东洋河南理工大学测绘与国土信息工程学院焦作454000 河南理工大学黄河生态文明与高质量发展研究院焦作454000

受云雨天气和卫星自身回访周期的影响,县域尺度水稻种植面积的提取往往难以获取完整时间序列的高空间分辨率影像,利用单一MODIS数据导致提取精度不高。针对上述问题以河南省优良水稻种植区原阳县为例,采用增强型自适应反射率时空融合模... 详细信息

受云雨天气和卫星自身回访周期的影响,县域尺度水稻种植面积的提取往往难以获取完整时间序列的高空间分辨率影像,利用单一MODIS数据导致提取精度不高。针对上述问题以河南省优良水稻种植区原阳县为例,采用增强型自适应反射率时空融合模型(Enhanced spatial and temporal adaptive reflectance fusion model,ESTARFM),融合中高分辨率的Landsat数据和高时间分辨率的MODIS数据,获取完整时间序列的归一化植被指数(Normalized difference vegetation index,NDVI)数据,经过TIMESAT滤波平滑处理后,利用研究区内水稻与其他地物的时序NDVI曲线,设置合理的NDVI阈值,采用决策树分类的方法提取水稻种植面积。结果显示,总体分类精度为92.23%,Kappa系数为0.9043。提取的水稻制图精度为96.73%,用户精度为93.51%,说明ESTARFM模型能很好地融合出高空间分辨率影像,解决数据缺失问题,可为县域尺度水稻种植面积提取提供参考。

关键词：水稻种植面积提取县域尺度增强型自适应反射率时空融合模型数据融合

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支架微观形貌和力学性能对管状牙本质再生的影响

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华西口腔医学杂志 2020年第3期38卷 314-318页

作者：刘艺萍王珏田子璐翟培淞王展麒周延民倪世磊吉林大学口腔医院种植中心长春130000

管状牙本质在牙体组织和牙再生过程中具有重要意义,因其不仅是原发性牙本质的结构特征,同时也能够影响牙的感觉功能的发挥和牙髓细胞的分化并可以为牙齿提供强有力的机械支持。支架是组织工程牙本质再生的三要素之一。多数牙本质再生的... 详细信息

管状牙本质在牙体组织和牙再生过程中具有重要意义,因其不仅是原发性牙本质的结构特征,同时也能够影响牙的感觉功能的发挥和牙髓细胞的分化并可以为牙齿提供强有力的机械支持。支架是组织工程牙本质再生的三要素之一。多数牙本质再生的实验涉及对支架微观形貌和力学性能的研究。支架材料的微观形貌和力学特征对成牙本质细胞分化、黏附等行为产生重要影响,直接影响着再生牙本质的组织结构。

关键词：管状牙本质支架成牙本质细胞再生牙本质

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Performance and Application of Double-layered Microcapsule Corrosion Inhibitors

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Journal of Wuhan University of Technology(Materials Science) 2024年第4期39卷 845-853页

作者：余海燕 wang Yingxiang wang Ruizhi HU Lintong wang Tianlei School of Materials Science and Engineering Tianjin Chengjian UniversityTianjin 300384China Tianjin Key Laboratory of Building Green Functional Materials Tianjin Chengjian UniversityTianjin 300384China

Double-layered microcapsule corrosion inhibitors were developed by sodium monofluorophosphate as the core material,polymethyl methacrylate as the inner wall material,and polyvinyl alcohol as the outer wall material combining the solvent evaporation method and spray drying *** protection by the outer capsule wall was used to prolong the service life of the corrosion *** dispersion,encapsulation,thermal stability of microcapsules,and the degradation rate of capsule wall in concrete pore solution were analyzed by ultra-deep field microscopy,scanning electron microscopy,thermal analyzer,and sodium ion release rate *** microcapsules were incorporated into mortar samples containing steel reinforcement,and the effects of double-layered microcapsule corrosion inhibitors on the performance of the cement matrix and the actual corrosion-inhibiting effect were *** experimental results show that the double-layered microcapsules have a moderate particle size and uniform distribution,and the capsules were completely *** microcapsules as a whole have good thermal stability below 230 ℃.The monolayer membrane structure microcapsules completely broke within 1 day in the simulated concrete pore solution,and the double-layer membrane structure prolonged the service life of the microcapsules to 80 days in the simulated concrete pore solution before the core material was completely *** mortar samples containing steel reinforcement incorporated with the double-layered microcapsule corrosion inhibitors still maintained a higher corrosion potential than the monolayer microcapsule corrosion inhibitors control group at 60 *** incorporation of double-layered microcapsules into the cement matrix has no significant adverse effect on the setting time and early strength.

关键词： corrosion inhibitors microcapsule double-layer structure potentiodynamic polarization curve

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Multiple-stage spatial-temporal cooperative guidance without time-to-go estimation

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CHINESE JOURNAL OF AERONAUTICS 2024年第9期37卷 399-416页

作者： wang, Chunyan wang, Weilin Dong, Wei wang, Jianan Deng, Fang Beijing Inst Technol Sch Aerosp Engn Beijing 100081 Peoples R China Beijing Inst Technol Natl Key Lab Autonomous Intelligent Unmanned Syst Beijing 100081 Peoples R China Beijing Inst Technol Chongqing Innovat Ctr Chongqing 401120 Peoples R China

This paper investigates the spatial-temporal cooperative guidance problem for multiple flight vehicles without relying on time-to-go information. First, a two-stage cooperative guidance strategy, namely the cooperative guidance and the Proportional Navigation Guidance (PNG) stage strategy, is developed to realize the spatial-temporal constraints in two dimensions. At the former stage, two controllers are designed and superimposed to satisfy both impact time consensus and impact angle constraints. Once the convergent conditions are satisfied, the flight vehicles will switch to the PNG stage to ensure zero miss distance. To further extend the results to three dimensions, a planar pursuit guidance stage is additionally imposed at the beginning of guidance. Due to the independence of time-to-go estimation, the proposed guidance strategy possesses great performance in satisfying complex spatial-temporal constraints even under flight speed variation. Finally, several numerical simulations are implemented to verify the effectiveness and advantages of the proposed results under different scenarios. (c) 2024 Production and hosting by Elsevier Ltd. on behalf of Chinese Society of Aeronautics and Astronautics. This is an open access article under the CC BY-NC-ND license (http://***/ licenses/by-nc-nd/4.0/).

关键词： Cooperative guidance Guided missiles Impact time consensus Impact angle constraint Spatial-temporal cooperative guidance SLIDING-MODE CONTROL IMPACT-TIME SALVO ATTACK ANGLE-CONTROL LAW MISSILES

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In situ reduction strategy towards high conductivity,anti-freezing and super-stretchable rGO based hydrogel for diverse flexible electronics

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Nano Research 2024年第5期17卷 4016-4022页

作者： Xin Zhang Junhao wang Mengyan wang Dongxu Liu Zhuo wang College of Resources and Environment University of Chinese Academy of SciencesBeijing 101408China Beijing Institute of Nanoenergy and Nanosystems Chinese Academy of ScienceBeijing 101400China

Hydrogels electrolytes with flexibility and high conductivity have been widely used in kinds of flexible ***,hydrogels always suffer from the inevitable freezing of water at subzero temperatures,which results in the sacrificing of their electrical ***,an anti-freezing,flexible hydrogel based on in situ reduction of graphene oxide(GO)and laponite has been developed as electrolyte for high performance supercapacitor and sensitive *** crosslinked GO and laponite in polyacrylamide(PAM)resulted in an enhanced mechanical property,while the in-situ reduction of GO in the hydrogel enhanced the conductivity and diminishes the aggregated of *** features guarantee a reliable electro signal as sensor and a high performance of the ***,in the process of preparation of reduced graphene oxide(rGO)hydrogel,the addition of ethylene glycol(EG)and KOH,endows the hydrogel antifreeze *** anti-freezing electrolyte can be stretched to a strain of 1600%and maintained a specific capacitance of 37.38 F·g^(-1) at-20℃.In addition,the photothermal conversion character of rGO in the hydrogel,endows it’s the potential application in wound *** overall merits of the hydrogel will open up a new avenue for sensitive sensor and energy storage device in practical applications.

关键词： hydrogel in-situ reduction flexible electronics low temperature tolerance photothermal therapy

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左束支区域起搏治疗慢性收缩性心力衰竭患者的有效性及安全性Meta分析

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中国循环杂志 2021年第11期36卷 1114-1120页

作者：成雨达李玉军齐金磊刘金玉王占启河北大学附属医院心内科河北省保定市071000

目的:探索左束支区域起搏(LBBAP)治疗慢性收缩性心力衰竭(心衰)患者的有效性及安全性。方法:在PubMed、Cochrane Library、Web of Science、Embase、中国知网、万方数据库、维普数据库检索关于LBBAP治疗慢性收缩性心衰患者的研究,根据... 详细信息

目的:探索左束支区域起搏(LBBAP)治疗慢性收缩性心力衰竭(心衰)患者的有效性及安全性。方法:在PubMed、Cochrane Library、Web of Science、Embase、中国知网、万方数据库、维普数据库检索关于LBBAP治疗慢性收缩性心衰患者的研究,根据纳入及排除标准筛选文献,提取有效性及安全性数据,进行Meta分析。结果:共纳入9篇文献、537例患者,LBBAP成功率为88.8%。Meta分析结果显示:LBBAP术中及随访时的起搏阈值未见明显差异[均数差(MD)=-0.20,95%CI:-0.46~0.05,P=0.11]。与基线相比,随访时心衰患者的B型利钠肽水平下降(标准MD=-1.35,95%CI:-1.61~-1.09),QRS波时限缩短(MD=-48.52,95%CI:-63.71~-33.32),左心室舒张末期内径(MD=-7.54,95%CI:-11.34~-3.73)及左心室收缩末期内径(MD=-13.62,95%CI:-16.31~-10.93)明显改善,左心室射血分数(MD=16.29,95%CI:12.09~20.49)明显提高,NYHA心功能分级(MD=-1.35,95%CI:-1.61~-1.09)明显降低,差异均有统计学意义(P均<0.05)。平均随访(8.3±6.0)个月,并发症发生率为6.1%,心衰再住院率为3.6%,死亡率为2.3%。结论:LBBAP治疗慢性收缩性心衰患者有效、安全,提示LBBAP可能会成为心脏再同步化治疗的一种替代方案。

关键词：左束支区域起搏收缩性心力衰竭 Meta分析心脏再同步化治疗

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