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Nano Research 2024年第7期17卷 6534-6543页

作者： Ya-Chuan Liang qing cao Yuan Deng Yong Wang Kai-Kai Liu Chong-Xin Shan School of Electronics and Information Zhengzhou University of Light IndustryZhengzhou 450002China Henan Key Laboratory of Diamond Optoelectronic Material and Devices Key Laboratory of Material PhysicsMinistry of EducationSchool of Physics and MicroelectronicsZhengzhou UniversityZhengzhou 450001China Academy for Quantum Science and Technology Zhengzhou University of Light IndustryZhengzhou 450002China Institute of Quantum Materials and Physics Henan Academy of SciencesZhengzhou 450046China

Easy non-radiative decay property of long-lived triplet excitons in aqueous solution obstructs their applications in aquatic *** reported phosphorescence phenomena in aqueous solution have excited researchers enormously but achieving full-color water-soluble phosphorescent carbon nanodots(CNDs)is still a challenging ***,full-color phosphorescence of water-soluble CNDs has been demonstrated by triggering their triplet excitons through nanospace domain confinement,and Förster energy resonance transfer is used for further tuning phosphorescence *** phosphorescence spans across most of the visible spectrum,ranging from 400 to 700 *** an aqueous solution,the CNDs exhibits blue,green,and red phosphorescence,lasting for approximately 6,10,and 7 s,***,the phosphorescence quantum yields are 11.85%,8.6%and 3.56%,making them readily discernible to the naked eyes and laying a solid foundation for practical ***,phosphorescence flexible optical display and bioimaging have been demonstrated by using the multicolor CNDs-based nanomaterials,showing distinct superiority for accuracy and complete display and imaging in complex emission background.

关键词： carbon nanodots triplet excitons multicolor aqueous solution

Prediction of contact resistance of electrical contact wear using different machine learning algorithms

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Friction 2024年第6期12卷 1250-1271页

作者： Zhen-bing CAI Chun-lin LI Lei YOU Xu-dong CHEN Li-ping HE Zhong-qing cao Zhi-nan ZHANG Tribology Research Institute Southwest Jiaotong UniversityChengdu 610031China State Key Laboratory of Mechanical System and Vibration Shanghai Jiao Tong UniversityShanghai 200240China

H62 brass material is one of the important materials in the process of electrical energy transmission and signal transmission,and has excellent performance in all *** the wear behavior of electrical contact pairs is particularly complex when they are in service,we evaluated the effects of load,sliding velocity,displacement amplitude,current intensity,and surface roughness on the changes in contact *** learning(ML)algorithms were used to predict the electrical contact performance of different factors after wear to determine the correlation between different factors and contact *** forest(RF),support vector regression(SVR)and BP neural network(BPNN)algorithms were used to establish RF,SVR and BPNN models,respectively,and the experimental data were trained and *** was proved that BP neural network model could better predict the stable mean resistance of H62 brass alloy after *** analysis shows that the load and current have great influence on the predicted electrical contact *** wear behavior of electrical contacts is influenced by factors such as load,sliding speed,displacement amplitude,current intensity,and surface roughness during *** learning algorithms can predict the electrical contact performance after wear caused by these *** results indicate that an increase in load,current,and surface roughness leads to a decrease in stable mean resistance,while an increase in displacement amplitude and frequency results in an increase in stable mean resistance,leading to a decline in electrical contact *** reduce testing time and costs and quickly obtain the electrical contact performance of H62 brass alloy after wear caused by different factors,three algorithms(random forest(RF),support vector regression(SVR),and BP neural network(BPNN))were used to train and test experimental results,resulting in a machine learning model suitable for predicting the stable mean

关键词： electrical contact wear contact resistance machine learning(ML) neural network

Synthesis and Exciplex Emission of a Tricyano-substituted 9-Phenylfluorene Compound

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有机化学 2024年第8期44卷 2595-2602页

作者： cao Hongtao cao qing Hu Yangjun Yu Zimeng Xie Xinmiao Chang Yongzheng Hou Pengfei Wang Shasha Xie Linghai State Key Laboratory of Organic Electronics and Information Displays College of Materials Science and EngineeringCollege of Chemistry and Life SciencesNanjing University of Posts&TelecommunicationsNanjing 210023 School of Flexible Electronics and Henan Institute of Flexible Electronics Henan UniversityZhengzhou 450046

Exciplex-emitters are attractive due to their distinct feature of easily achieving small singlet-triplet energy splitting for thermally activated delayed fluorescence(TADF),but face with challenges in convenient design of electron *** 9-phenylfluorene-based acceptor 9-[6-(2-cyano-7-isocyano-9-phenyl-9H-fluoren-9-yl)-9-ethyl-9H-carbazol-3-yl]-9-phenyl-9H-fluorene-2,7-dicarbonitrile(TriCNDPFCz)was designed and synthesized through *** mixing TriCNDPFCz with conventional donor 1,1-bis[(di-4-tolylamino)phenyl]cyclohexane(TAPC),bright exciplex-TADF was obtained with a maximum current efficiency of 46.7 cd·A^(-1),power efficiency of 52.3 lm·W^(-1)and external quantum efficiency of 14.5%.The experimental characterizations indicate that tricyano-substitution in 9-phenylfluorene skeleton can form strong electron-accepting ability,which is useful and convenient for constructing electron acceptor in exciplex emission.

关键词： 9-phenylfluorene cyano-substitution asymmetric modification exciplex emission

Orientation controlled photogenerated carriers on selfsupporting CdS/Ni_(3)S_(2) paper toward photocatalytic hydrogen evolution and biomass upgrading

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Rare Metals 2024年第5期43卷 2015-2025页

作者： Xiao-Yan Liu qing cao Gui-Xiang Li Hui Liu Li-Li Zeng Li-Li Zhao Bin Chang Xi-Wen Wang Hong Liu Wei-Jia Zhou Institute for Advanced Interdisciplinary Research School of Chemistry and Chemical EngineeringUniversity of JinanJinan 250022China Institute of Chemical Sciences and Engineering Ecole Polytechnique Federale de Lausanne1015LausanneSwitzerland KAUST Catalysis Center King Abdullah University of Science and TechnologyThuwal 23955-6900Kingdom of Saudi Arabia School of Environment and Energy South China University of TechnologyGuangzhou Higher Education Mega CenterGuangzhou 510006China State Key Laboratory of Crystal Materials Shandong UniversityJinan250100China School of Mechanical Engineering Xi'an Jiaotong UniversityXi'an 710054China

The appropriate regulation of band structure is an effective strategy in constructing efficient photocatalytic *** photocatalytic system mainly employs powder photocatalysts,which makes their recovery reliant on expensive separation processes and severely limits their industrial ***,we constructed a novel CdS/Ni_(3)S_(2)heterostructure using free-standing and flexible nickel fiber paper as the *** regulated energy band structure achieves effective electron–hole *** as-synthesized flexible photocatalyst exhibits considerable photocatalytic activity toward the H_(2)evolution reaction under visible-light irradiation,with an H_(2)production rate of5.63μmol·cm^(-2)·h^(-1)(14.1 mmol·g^(-1)cat·h^(-1)according to the catalyst loading content).Additionally,the otherwisewasted excited holes simultaneously drive organic transformations to yield value-added organic products,thus markedly improving the photocatalytic H_(2)evolution *** a photocatalytic system is scaled up further,where a self-supported 20 cm×25 cm sample achieves a champion H_(2)production rate of 60-80μmol·h^(-1)under practical sun *** newly developed self-supported photocatalyst produces opportunities for practical solar H2production with biomass upgrading.

关键词： Self-supporting photocatalyst CdS/Ni_(3)S_(2) heterojunction Hydrogen evolution Biomass upgrading Large-scaleapplication

桥墩承台大体积混凝土温度场监测与有限元分析

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铁道建筑 2024年第9期64卷 86-91页

作者：曹青中铁建设集团有限公司北京100040 北京工业大学工程抗震与结构诊治北京市重点实验室北京100124

为控制大体积混凝土浇筑后里表温差过大及温度裂缝的不利影响,通过对无冷却水管试验墩和有冷却水管承台的大体积混凝土温度场进行监测,研究在有无冷却水管降温措施下大体积混凝土内部温度场的分布及变化规律,并建立有限元模型分析有限... 详细信息

为控制大体积混凝土浇筑后里表温差过大及温度裂缝的不利影响,通过对无冷却水管试验墩和有冷却水管承台的大体积混凝土温度场进行监测,研究在有无冷却水管降温措施下大体积混凝土内部温度场的分布及变化规律,并建立有限元模型分析有限元模拟结果与实测数据之间的差异。结果表明:大体积混凝土浇筑后,混凝土升温速率大于降温速率;布设冷却水管降温措施可以明显降低大体积混凝土中心温度;升降温阶段,混凝土内部和表面温度升降温速率基本相同,且从内到外温度变化呈递减趋势,但无线性关系;有限元模拟结果与实测数据吻合较好。

关键词：大体积混凝土桥墩承台现场监测水化热分析温度场降温措施

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时滞和阶次未知的双率采样输出误差系统辨识

控制与决策 2024年第9期39卷 3006-3012页

作者：焦帆曹余庆谢莉江南大学物联网工程学院江苏无锡214122 无锡爱德旺斯科技有限公司江苏无锡214161

针对时滞和阶次未知的双率采样输出误差系统,在有限采样数据条件下,提出一种辅助模型正交匹配追踪迭代辨识算法.首先,根据双率采样数据建立目标系统的辨识模型;其次,考虑到输入通道的时滞与系统阶次未知,采用过参数化方法,通过设置足够... 详细信息

针对时滞和阶次未知的双率采样输出误差系统,在有限采样数据条件下,提出一种辅助模型正交匹配追踪迭代辨识算法.首先,根据双率采样数据建立目标系统的辨识模型;其次,考虑到输入通道的时滞与系统阶次未知,采用过参数化方法,通过设置足够长的无噪输出数据和输入数据回归项,得到一个稀疏度为待辨识参数个数的稀疏系统;然后,结合辅助模型思想和压缩感知中的稀疏恢复方法实现参数向量和无噪输出的交互估计,即利用正交匹配追踪算法估计参数向量,再利用该估计值构建辅助模型计算无噪输出,并以此更新参数估计向量;最后,根据得到的参数向量结构计算系统的阶次与通道的时滞.仿真实验表明,所提出算法能够利用少量采样数据实现系统参数、时滞和阶次的高精度联合估计.

关键词：双率采样系统参数辨识时滞估计阶次估计正交匹配追踪辅助模型

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大孔径太赫兹波成像光学系统设计

中国光学（中英文） 2024年第2期17卷 374-381页

作者：曹一青沈志娟莆田学院机电与信息工程学院福建莆田351100 福建省激光精密加工工程技术研究中心福建莆田351100

太赫兹波具有高穿透性、低能性及指纹谱性等特征,被广泛应用于探测领域,因此,设计太赫兹波成像光学系统具有重要的意义和广泛的应用前景。首先,以四块透镜构成的天塞物镜为参考结构,应用近轴光学系统像差理论构建系统像差平衡方程,给出... 详细信息

太赫兹波具有高穿透性、低能性及指纹谱性等特征,被广泛应用于探测领域,因此,设计太赫兹波成像光学系统具有重要的意义和广泛的应用前景。首先,以四块透镜构成的天塞物镜为参考结构,应用近轴光学系统像差理论构建系统像差平衡方程,给出了系统初始结构参数求解函数和方法,再结合光学设计软件进一步校正系统像差,最终设计了一种用于太赫兹波探测的大孔径光学成像系统。该光学系统由4块同轴折射透镜构成,焦距为70 mm,F数为1.4,全视场角为8°,在奈奎斯特频率10 lp/mm处全视场角范围内的调制传递函数(MTF)值均大于0.32,各视场内的弥散斑均方根(RMS)半径均小于艾里斑半径。最后对系统各种公差进行分析和讨论。设计结果表明,本文设计的太赫兹波探测光学成像系统具有孔径大、结构简单且紧凑、成像质量较好且加工性易于实现等特点,满足设计要求,它在太赫兹波段高分辨率探测领域具有重要应用价值。

关键词：光学系统设计太赫兹波大孔径像差平衡公差分析

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全肠道坏死性小肠结肠炎的诊治现状与困境

中国实用儿科杂志 2024年第5期39卷 338-341页

作者：曹旭清沈淳国家儿童医学中心复旦大学附属儿科医院外科新生儿外科上海201102

全肠道坏死性小肠结肠炎(necrotizing enterocolitis totalis,NEC-T)是坏死性小肠结肠炎(NEC)中最严重的类型,病情发展迅速,预后不良风险较高,且目前缺少普遍认可的诊疗策略。该文就NEC-T的危险因素、治疗决策及预后、治疗过程中可能面... 详细信息

全肠道坏死性小肠结肠炎(necrotizing enterocolitis totalis,NEC-T)是坏死性小肠结肠炎(NEC)中最严重的类型,病情发展迅速,预后不良风险较高,且目前缺少普遍认可的诊疗策略。该文就NEC-T的危险因素、治疗决策及预后、治疗过程中可能面临的伦理问题等进行概述,并阐述临床诊治过程中的难题与困境。

关键词：坏死性小肠结肠炎全肠道坏死性新生儿

金融科技赋能与实体经济修复——基于新冠疫情的冲击

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南开管理评论 2024年第6期27卷 16-26页

作者：王红建曹晴曹瑜强江西财经大学财经数据科学重点实验室江西财经大学金融学院广东外语外贸大学会计学院

探究我国实体企业在遭遇新冠疫情等不利冲击后如何稳定投资,对实体经济实现平稳发展意义重大。本文探究新冠疫情冲击背景下金融科技对实体企业投资的影响及内在机理。研究发现:金融科技显著提高了危机冲击下实体企业投资水平,该结论经... 详细信息

探究我国实体企业在遭遇新冠疫情等不利冲击后如何稳定投资,对实体经济实现平稳发展意义重大。本文探究新冠疫情冲击背景下金融科技对实体企业投资的影响及内在机理。研究发现:金融科技显著提高了危机冲击下实体企业投资水平,该结论经过系列稳健性检验后仍然成立。机制识别发现:金融科技能够显著降低抵押资产和会计信息在银行信贷中的作用,缓解实体企业在危机期间的资金约束,帮助实体企业抵抗危机的冲击。拓展性检验发现:金融科技对实体企业投资的促进作用对于成立时间更短及所在地区传统银行业欠发达的样本更加显著。经济后果检验发现:微观层面上,金融科技的发展能够增强危机冲击下的实体企业韧性,提高企业财务杠杆,但是对经营绩效的影响较为有限;宏观层面上,金融科技能显著降低危机发生后的宏观经济波动。本研究从实体企业投资视角揭示了金融科技影响实体经济运行规律的内在机理,在实践上为金融科技发展及经济复苏政策的制定提供了理论依据。

关键词：新冠疫情冲击金融科技经济修复实体企业投资

附加阻尼网的斜底式TLD减震控制理论与试验研究

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建筑结构学报 2024年第4期45卷 72-85页

作者：孙澔鼎何浩祥程扬曹青北京工业大学工程抗震与结构诊治北京市重点试验室北京100124 中铁建设集团有限公司北京100040

为解决传统调谐液体阻尼器(tuned liquid damper,TLD)中有效阻尼偏小、用水量偏大等问题,提出一种附加阻尼网的斜底式水箱调谐液体阻尼器(damping net and sloped-bottom tuned liquid damper,DNS-TLD),将水箱底面倾斜的TLD与阻尼网有... 详细信息

为解决传统调谐液体阻尼器(tuned liquid damper,TLD)中有效阻尼偏小、用水量偏大等问题,提出一种附加阻尼网的斜底式水箱调谐液体阻尼器(damping net and sloped-bottom tuned liquid damper,DNS-TLD),将水箱底面倾斜的TLD与阻尼网有机结合,强化水箱内液体晃动,可提供更大附加阻尼比并降低用水量。建立了附加DNS-TLD结构的力学模型,阐述其减震机制,提出了一种简便估算DNS-TLD总等效阻尼比的方法。通过单层钢框架振动台试验,对比分析了附加DNS-TLD及其他不同类型TLD的减震性能。将试验结果与数值模拟结果进行比较,进一步验证减震规律以及各类TLD总等效阻尼比估算方法的准确性。在此基础上,对附加DNS-TLD的10层钢筋混凝土框架结构进行地震作用下的动力时程分析,验证DNS-TLD对实际结构减震控制的有效性。振动台试验与数值模拟结果均表明,DNS-TLD有效结合了斜底式水箱TLD与阻尼网的优点,表现出更优的阻尼性能,相比于其他类型的TLD,其减震效率更高,鲁棒性和工程适用性更强。

关键词：调谐液体阻尼器斜底式水箱阻尼网调谐减震附加阻尼比