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Optimizing circumferential assembly angle of rotor parts connected by curvic couplings based on acquired tooth surface error data

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Chinese Journal of Aeronautics 2024年第3期37卷 404-416页

作者： Huibin SUN Meng LIU yingzhi ZHANG Chenle WEI Key Laboratory of High Performance Manufacturing for Aero Engine Ministry of Industry and Information TechnologyNorthwestern Polytechnical UniversityXi’an 710072China AECC South Industry Company Limited Zhuzhou 412002China

Due to the excellent self-centering and load-carrying capability,curvic couplings have been widely used in advanced aero-engine rotors.However,curvic tooth surface errors lead to poor assembly precision.Traditional physical-master-gauge-based indirect tooth surface error measurement and circumferential assembly angle optimization methods have the disadvantages of high cost and weak generality.The unknown tooth surface fitting mechanism is a big barrier to assembly precision prediction and improvement.Therefore,this work puts forward a data-driven assembly simulation and optimization approach for aero-engine rotors connected by curvic couplings.The origin of curvic tooth surface error is deeply investigated.Using 5-axis sweep scan method,a large amount of high-precision curvic tooth surface data are acquired efficiently.Based on geometric models of parts,the fitting mechanism of curvic couplings is uncovered for assembly precision simulation and prediction.A circumferential assembly angle optimization model is developed to decrease axial and radial assembly runouts.Experimental results show that the assembly precision can be predicted accurately and improved dramatically.By uncovering the essential principle of the assembly precision formation and proposing circumferential assembly angle optimization model,this work is meaningful for assembly quality,efficiency and economy improvement of multistage aero-engine rotors connected by curvic couplings.

关键词： Curvic couplings Tooth surface error Assembly precision Axial and radial runouts Circumferential assembly angle

Continuous preparation of strong and tough PVA nanocomposite fibers by mechanical stretching-assisted salting-out treatment

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Nano Research 2024年第4期17卷 3156-3163页

作者： Hang Chen Guangze Yang yingzhi Sun Yichao Xu Mingjie Liu Key Laboratory of Bioinspired Smart Interfacial Science and Technology of Ministry of Education School of ChemistryBeihang UniversityBeijing 100191China Research Institute for Frontier Science Beihang UniversityBeijing 100191China International Research Institute for Multidisciplinary Science Beihang UniversityBeijing 100191China

Polymer composite fibers with superior properties such as excellent combined strength and toughness and biocompatibility can be used in high-tech applications of braided protective devices and smart wearable,however the research of high-performance polymer composite fiber remains in the infant stage.Here we present a strategy to produce strong and tough anisotropic polymer nanocomposite fibers with orientedly aligned salt rods using mechanical stretching-assisted salting-out treatment.The prepared nanocomposite fibers have a tensile strength of up to 786±2.7 MPa and an elongation at break of 81%,and the anisotropic fibers exhibit good transmission of mechanical vibration in the longitudinal direction with high resolution.During the fabrication process,the salt builds up into oriented rods during the directional salting process,and the polymer is confined to the 150 nm domain between the rods after the solvent is completely evaporated,giving the nanocomposite fibers superior mechanical properties.The presented strategy can be applied to the continuous mass production of nanocomposite fibers and is also generalizable to other polymer nanocomposites,which could extend the applicability of nanocomposite fibers to conditions involving more demanding mechanical loading and mechanical vibration transmission.

关键词： poly(vinyl alcohol)(PVA)nanofibers oriented structure ultrastrong and stiff mechanical vibration transmission salting out continuous production

Precise regulation of the phase transformation for pyrolusite during the reduction roasting process

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International Journal of Minerals,Metallurgy and Materials 2024年第1期31卷 81-90页

作者： Ruofeng Wang Peng Gao Shuai Yuan Yanjun Li yingzhi Liu Cheng Huang School of Resources and Civil Engineering Northeastern UniversityShenyang 110819China National-Local Joint Engineering Research Center of High-efficient Exploitation Technology for Refractory Iron Ore Resources Shenyang 110819China

The mechanism involved in the phase transformation process of pyrolusite (MnO_(2)) during roasting in a reducing atmosphere was systematically elucidated in this study,with the aim of effectively using low-grade complex manganese ore resources.According to single-factor experiment results,the roasted product with a divalent manganese (Mn^(2+)) distribution rate of 95.30% was obtained at a roasting time of 25 min,a roasting temperature of 700℃,a CO concentration of 20at%,and a total gas volume of 500 mL·min^(-1),in which the manganese was mainly in the form of manganosite (MnO).Scanning electron microscopy and Brunauer–Emmett–Teller theory demonstrated the microstructural evolution of the roasted product and the gradual reduction in the pyrolusite ore from the surface to the core Thermodynamic calculations,X-ray photoelectron spectroscopy,and X-ray diffractometry analyses determined that the phase transformation of pyrolusite followed the order of MnO_(2)→Mn_(2)O_(3)→Mn_(3)O_(4)→MnO phase by phase,and the reduction of manganese oxides in each valence state proceeded simultaneously.

关键词： pyrolusite phase transformation reduction roasting microstructural evolution reaction mechanism

The Chinese Consumers’Service Quality Satisfaction Differences of Cruise Tourism and Precision Marketing Strategy

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Journal of Tourism and Hospitality Management 2024年第1期12卷 1-11页

作者： ZHANG Lingling CHEN Yu GUO yingzhi Putian University PutianChina Fudan University ShanghaiChina

The paper selected Chinese Cruise Line as the case study. Having based on the survey data of Chinese cruise tourism consumers, the factor analysis method, one-way analysis of variances method, cluster analysis method, and other quantitative and qualitative methods were taken to analyze Chinese consumers’ satisfaction differences of cruise tourism service quality with different segmentation markets and clusters markets, and the reasons of satisfaction differences were also explored. Then precision marketing strategy of Chinese cruise tourism with different segmentation markets and clusters markets from the supply-side reform perspective was discussed. The purpose of current research was to provide suggestions of precision management and precision marketing of Chinese cruise tourism for relevant enterprises and government departments.

关键词： cruise tourism service quality satisfaction market segmentation precision marketing

病有所医、病无所恐:我国农村合作医疗制度发展历程、运行逻辑与未来进路

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甘肃行政学院学报 2024年第1期 28-38,125页

作者：周巍尚樱之新疆大学政治与公共管理学院乌鲁木齐830000

新中国成立70多年来,国家一直在探索如何更好地为农村人口供给可负担、高质量的医疗保障,在经历了从传统农村合作医疗到新型农村合作医疗的不间断探索后,形成了中国特色社会主义制度下的农民医疗保障全覆盖模式,这种连续性、从未间断的... 详细信息

新中国成立70多年来,国家一直在探索如何更好地为农村人口供给可负担、高质量的医疗保障,在经历了从传统农村合作医疗到新型农村合作医疗的不间断探索后,形成了中国特色社会主义制度下的农民医疗保障全覆盖模式,这种连续性、从未间断的合作医疗形成了新中国治理变迁的独特经验,是形成国家发展的“中国奇迹”的一种基础保障力量。以历史变迁的长镜头观之,我国合作医疗历经了从“集体福利”“个体消费”“民生服务”走向基本公共服务均等化的实践轨迹,各个阶段都努力在现实需求与资源约束的矛盾运动下最大限度保证农民群众“人人看得起病”。为了在更高水平上保障农民“病有所医、病无所恐”,未来需要继续大力推动城乡居民基本医疗保障制度的一体化改革,扩展农民群众医保报销范围、降低个人承担份额,最终实现城乡居民人人享有健康权利的国家战略规划,迈向以人民为中心的社会主义“共同健康”之路。

关键词：农村合作医疗基本公共服务共同健康

Subtle side chain modification of triphenylamine‐based polymer hole‐transport layer materials produces efficient and stable inverted perovskite solar cells

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Interdisciplinary Materials 2022年第2期1卷 281-293页

作者： Yue-Min Xie Qin Yao Qifan Xue Zixin Zeng Tianqi Niu yingzhi zhou Ming-Peng Zhuo Sai-Wing Tsang Hin-Lap Yip Yong Cao Institute of Polymer Optoelectronic Materials and Devices State Key Laboratory of Luminescent Materials and DevicesSouth China University of TechnologyGuangzhouP.R.China Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates(South China University of Technology) GuangzhouP.R.China Department of Materials Science and Engineering City University of Hong KongKowloonHong KongChina School of Energy and Environmental Science City University of Hong KongKowloonHong KongChina

Polymer hole-transport layers(HTLs)are critical components of inverted perovskite solar cells(IPVSCs).Triphenylamine derivatives PTAA(poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine])and Poly-TPD(poly[N,N′-bis(4-butylphenyl)-N,N′-bis(phenyl)benzidine])have been widely adopted as hole-transport materials due to their perovskite passivation effects and suitable energy levels.However,the passivation mechanism(i.e.,the functional group responsible for perovskite passivation)of triphenylamine derivative polymers remains unclear,hindering the development and application of this polymer type.Here,we develop a novel Poly-TPD derivative,S-Poly-TPD,by replacing the n-butyl functional group of Poly-TPD with an isobutyl group to explore the influence of alkyl groups on HTL performance and top-deposited perovskite properties.Compared with Poly-TPD,the increased CH_(3)-terminal unit density and the decreased spatial distance between the-CH-CH_(3) and-CH_(2)-CH_(3) units and the benzene ring in S-Poly-TPD not only enhanced the hole-transport ability but also improved the perovskite passivation effect,revealing for the first time the role of the alkyl groups in perovskite passivation.As a result,the S-Poly-TPD-based IPVSCs demonstrated high power-conversion efficiencies of 15.1% and 21.3% in wide-bandgap[MAPbI_(2)Br(SCN)0.12]and normal-bandgap[(FAPbI_(3))0.92(MAPbBr_(3))0.08]devices,respectively.

关键词： alkyl group inverted perovskite solar cells(IPVSCs) perovskite passivation polymer hole transport layers(HTLs) Poly-TPD,PTAA

基于工程设计的跨学科实践活动设计思路与实施策略

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课程．教材．教法 2024年第1期44卷 114-119页

作者：张颖之首都师范大学教师教育学院北京100037

依据工程设计的思路开展跨学科实践活动可为落实新课程的理念和要求提供有力支撑。工程设计的内涵要点包括:识别和界定工程问题,为设计解决方案制定标准和限制;开发可能的解决方案,尝试将解决方案可视化;优化设计方案,在多种可能的解决... 详细信息

依据工程设计的思路开展跨学科实践活动可为落实新课程的理念和要求提供有力支撑。工程设计的内涵要点包括:识别和界定工程问题,为设计解决方案制定标准和限制;开发可能的解决方案,尝试将解决方案可视化;优化设计方案,在多种可能的解决方案中比较和权衡,反复迭代改进设计;科学与工程既有区别也有共性,共同推动社会进步。基于工程设计的跨学科实践活动思路框架包括问题情境、设计方案、优化迭代、走向社会四个学习环节。情境学习是跨学科实践活动设计的基础,学科融合是跨学科实践活动遵循的线索,合作实践是跨学科实践活动开展的方式,多元评价是跨学科实践活动实施的关键。

关键词：跨学科实践工程设计新课程学科融合合作实践

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机械通气脱机重要环节——准确评估呼吸肌力

中华危重病急救医学 2024年第4期36卷 337-339页

作者：秦英智高心晶天津第三中心医院重症医学科天津300170

机械通气(MV)是抢救呼吸衰竭患者的有力手段。由于呼吸衰竭患者病因及基础呼吸功能各异,常出现脱机失败。MV时间延长常伴各种并发症。了解呼吸衰竭的病理生理学变化、加强呼吸力学监测有助于优化MV参数设置、减轻呼吸机相关性肺损伤及... 详细信息

机械通气(MV)是抢救呼吸衰竭患者的有力手段。由于呼吸衰竭患者病因及基础呼吸功能各异,常出现脱机失败。MV时间延长常伴各种并发症。了解呼吸衰竭的病理生理学变化、加强呼吸力学监测有助于优化MV参数设置、减轻呼吸机相关性肺损伤及尽早脱机。脱机成败取决于多种因素,最主要的因素为呼吸肌力、呼吸负荷和呼吸驱动强度。自主呼吸试验(SBT)是脱机过程的重要一环,实施SBT的主要目的是筛选脱机患者和时机、寻找不能通过SBT的可逆原因。由于SBT评估脱机预后的准确率约为85%,对于脱机困难患者,仅凭临床评估是不够的。规范测定脱机指标有利于准确评估脱机困难患者呼吸肌力,提高脱机成功率。

关键词：机械通气脱机自主呼吸试验浅快呼吸指数最大吸气压综合脱机指数

数字政府背景下西北边疆民族地区基层干部数字能力提升研究

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秘书 2024年第1期 73-80页

作者：周巍尚樱之新疆大学政治与公共管理学院

基层干部的数字素养、数字能力是政府数字化转型的基本要求,也是推进中国式现代化的重要保障。提升西北边疆民族地区基层干部数字能力是助推丝绸之路经济带建设、促进数字政府区域间协同发展的关键。在西北边疆民族地区数字政府建设进程... 详细信息

基层干部的数字素养、数字能力是政府数字化转型的基本要求,也是推进中国式现代化的重要保障。提升西北边疆民族地区基层干部数字能力是助推丝绸之路经济带建设、促进数字政府区域间协同发展的关键。在西北边疆民族地区数字政府建设进程中,由于数字资源、数字观念等方面的局限,基层干部面临数字认知能力、数字应用能力、数字服务能力和数字协同能力等方面的现实挑战,难以充分利用数字资源建立科学决策机制、提供精准高效服务。鉴于此,可从构建数字教育框架、匹配数字要素投入、提升数字服务能力、健全数字协同体系等方面“多管齐下”,为提高西北边疆民族地区数字政府效能提供数字人才保障,推进数字政府的精细运营和高质量发展。

关键词：基层干部数字能力数字政府高质量发展