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连接界面黏滑摩擦行为的非线性载荷重构方法

振动工程学报 2024年第2期37卷 200-209页

作者：王东范宣华张周锁中国工程物理研究院总体工程研究所四川绵阳621999 西安交通大学机械工程学院陕西西安710049

提出一种连接界面黏滑摩擦行为的非线性载荷重构方法。基于非线性动力学子结构建模方法,将复杂连接结构视作线性子结构和非线性连接两部分,通过虚拟非线性激励载荷进行关联。以线性子结构为研究对象,采用两次动刚度矩阵求逆的反转技术... 详细信息

提出一种连接界面黏滑摩擦行为的非线性载荷重构方法。基于非线性动力学子结构建模方法,将复杂连接结构视作线性子结构和非线性连接两部分,通过虚拟非线性激励载荷进行关联。以线性子结构为研究对象,采用两次动刚度矩阵求逆的反转技术消除传递函数的病态奇异性,建立观测点自由度和非线性连接自由度之间的传递关系。考虑连接界面黏滑摩擦行为的影响,将观测的非线性动力响应进行谐波级数展开,直接辨识连接界面的局部非线性接触载荷。利用螺栓连接梁结构的数值仿真和实验结果进行验证。结果表明:重构的虚拟非线性激励载荷能够直接反映连接界面黏滑摩擦行为的影响,并且能够有效地识别螺栓连接界面预紧性能的变化。

关键词：非线性载荷重构预紧状态识别连接界面黏滑摩擦

共线反射式二次谐波实验中二阶非线性极化率的定量测定

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Chinese Journal of Chemical Physics 2024年第2期37卷 171-176,I0101页

作者：赵璇严力耕张文凯北京师范大学物理系应用光学北京市重点实验室北京100875

偏振二次谐波是一种广泛使用的对称性表征技术.然而,在共线反射式实验构型中,光路中必不可少的分束器会导致基频光和倍频光的偏振状态经透射或反射后发生改变,从而导致二次谐波信号的偏振态发生畸变,进而影响二阶非线性极化率的定量测... 详细信息

偏振二次谐波是一种广泛使用的对称性表征技术.然而,在共线反射式实验构型中,光路中必不可少的分束器会导致基频光和倍频光的偏振状态经透射或反射后发生改变,从而导致二次谐波信号的偏振态发生畸变,进而影响二阶非线性极化率的定量测定本文提出了一种基于菲涅尔系数的数据校正方法来解决这个问题,从而实现归一化二阶非线性极化率的定量测定,进一步通过理论模拟和实验证明了该方法的有效性和通用性.

关键词：二次谐波偏振态畸变分束器二阶非线性极化率

Properties of radiation defects and threshold energy of displacement in zirconium hydride obtained by new deep-learning potential

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Chinese Physics B 2024年第7期33卷 456-465页

作者：王玺唐孟蒋明璇陈阳春刘智骁邓辉球 School of Physics and Electronics Hunan UniversityChangsha 410082China College of Materials Science and Engineering Hunan UniversityChangsha 410082China

Zirconium hydride(ZrH_(2)) is an ideal neutron moderator material. However, radiation effect significantly changes its properties, which affect its behavior and the lifespan of the reactor. The threshold energy of displacement is an important quantity of the number of radiation defects produced, which helps us to predict the evolution of radiation defects in ZrH_(2).Molecular dynamics(MD) and ab initio molecular dynamics(AIMD) are two main methods of calculating the threshold energy of displacement. The MD simulations with empirical potentials often cannot accurately depict the transitional states that lattice atoms must surpass to reach an interstitial state. Additionally, the AIMD method is unable to perform largescale calculation, which poses a computational challenge beyond the simulation range of density functional theory. Machine learning potentials are renowned for their high accuracy and efficiency, making them an increasingly preferred choice for molecular dynamics simulations. In this work, we develop an accurate potential energy model for the ZrH_(2) system by using the deep-potential(DP) method. The DP model has a high degree of agreement with first-principles calculations for the typical defect energy and mechanical properties of the ZrH_(2) system, including the basic bulk properties, formation energy of point defects, as well as diffusion behavior of hydrogen and zirconium. By integrating the DP model with Ziegler–Biersack–Littmark(ZBL) potential, we can predict the threshold energy of displacement of zirconium and hydrogen in ε-ZrH_(2).

关键词： zirconium hydride deep learning potential radiation defects molecular dynamics threshold energy of displacement

One-shot synthesis of heavy-atom-modified carbazole-fused multi-resonance thermally activated delayed fluorescence materials

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Science China Materials 2024年第9期67卷 2789-2795页

作者： Jia-Jun Hu Jia-Qi Liang Zhi-Ping Yan Hua-Xiu Ni Xiang-Ji Liao You-xuan Zheng State Key Laboratory of Coordination Chemistry Jiangsu Key Laboratory of Advanced Organic MaterialsSchool of Chemistry and Chemical EngineeringNanjing UniversityNanjing210023China Green Catalysis Center and College of ChemistryZhengzhou UniversityZhengzhou450001China

Efficient multi-resonance thermally activated delayed fluorescence(MR-TADF)materials hold significant potential for applications in organic light-emitting diodes(OLEDs)and ultra-high-definition ***,the stringent synthesis conditions and low yields typically associated with these materials pose substantial challenges for their practical *** this study,we introduce an innovative strategy that involves peripheral modification with sulfur and selenium atoms for two materials,CFDBNS and *** approach enables a directed one-shot borylation process,achieving synthesis yields of 66%and 25%,respectively,while also enhancing reverse intersystem crossing *** emitters exhibit ultra-narrowband sky-blue emissions centered around 474 nm,with full width at half maximum(FWHM)values as narrow as 19 nm in dilute toluene solutions,along with high photoluminescence quantum yields of 98%and 99%in doped films,*** OLEDs based on CFDBNS and CFDBNSe display sky-blue emissions with peaks at 476 and 477 nm and exceptionally slender FWHM values of 23 ***,the devices demonstrate remarkable performances,achieving maximum external quantum efficiencies of 24.1%and 27.2%.This work presents a novel and straightforward approach for the incorporation of heavy atoms,facilitating the rapid construction of efficient MR-TADF materials for OLEDs.

关键词： one-shot synthesis multi-resonance thermally activated delayed fluorescence carbazole-fused dual-boron embedded framework ultra-narrowband emission organic light-emitting diode

Predictive defect detection for prototype additive manufacturing based on multi-layer susceptibility discrimination

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Advances in Manufacturing 2023年第3期11卷 407-427页

作者： Jing-Hua Xu Lin-xuan Wang Shu-You Zhang Jian-Rong tan State Key Lab of Fluid Power and Mechatronic Systems Zhejiang UniversityHangzhou 310058People's Republic of China Zhejiang Key Lab of Advanced Manufacturing Technology Zhejiang UniversityHangzhou 310058People's Republic of China Engineering Research Centre for Design Engineering and Digital Twin of Zhejiang Province Hangzhou 310058People's Republic of China Zhejiang-Singapore Innovation and AI Joint Research Lab Hangzhou 310027People's Republic of China

This paper presents a predictive defect detection method for prototype additive manufacturing(AM)based on multilayer susceptibility discrimination(MSD).Most current methods are significantly limited by merely captured images,disregarding the differences between layer-by-layer manufacturing approaches,without combining transcendental *** visible parts,originating from the prototype of conceptual design,are determined based on spherical flipping and convex hull theory,on the basis of which theoretical template image(TTI)is rendered according to photorealistic *** addition,to jointly consider the differences in AM processes,the finite element method(FEM)of transient thermal-structure coupled analysis was conducted to probe susceptible regions where defects appeared with a higher *** by prior knowledge acquired from the FEM analysis,the MSD with an adaptive threshold,which discriminated the sensitivity and susceptibility of each layer,was implemented to determine *** anomalous regions were detected and refined by superimposing multiple-layer anomalous regions and comparing the structural features extracted using the Chan-Vese(CV)model.A physical experiment was performed via digital light processing(DLP)with photosensitive resin of a non-faceted scaled V-shaped engine block prototype with cylindrical holes using a non-contact *** MSD method is practical for detecting defects and is valuable for a deeper exploration of barely visible impact damage(BVID),thereby reducing the defect of prototypical mechanical parts in engineering machinery or process equipment via intellectualized machinevision.

关键词： Predictive defects detection Additive manufacturing(AM) Convex hull theory Finite element method(FEM) Multi-layer susceptibility discrimination(MSD)

Dimensionality-driven metal to Mott insulator transition in two-dimensional 1T-TaSe2

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National Science Review 2024年第3期11卷 108-118页

作者： Ning Tian Zhe Huang Bo Gyu Jang Shuaifei Guo Ya-Jun Yan Jingjing Gao Yijun Yu Jinwoong Hwang Cenyao tang Meixiao Wang xuan Luo Yu Ping Sun Zhongkai Liu Dong-Lai Feng Xianhui Chen Sung-Kwan Mo Minjae Kim Young-Woo Son Dawei Shen Wei Ruan Yuanbo Zhang State Key Laboratory of Surface Physics New Cornerstone Science Laboratory and Department of PhysicsFudan University Shanghai Qi Zhi Institute Shanghai Research Center for Quantum Sciences Institute for Nanoelectronic Devices and Quantum Computing Fudan University Zhangjiang Fudan International Innovation Center Fudan University State Key Laboratory of Functional Materials for Informatics Shanghai Institute of Microsystem and Information Technology(SIMIT)Chinese Academy of Sciences School of Physical Science and Technology ShanghaiTech University Korea Institute for Advanced Study School of Emerging Technology and Department of Physics University of Science and Technology of China Advanced Light Source Lawrence Berkeley National Laboratory ShanghaiTech Laboratory for Topological Physics Key Laboratory of Materials Physics Institute of Solid State Physics Hefei Institutes of Physical ScienceChinese Academy of Sciences High Magnetic Field Laboratory Hefei Institutes of Physical Science Chinese Academy of Sciences Collaborative Innovation Centre of Advanced Microstructures Nanjing University Department of Physics University of Science and Technology of China and Key Laboratory of Strongly Coupled Quantum Matter Physics Chinese Academy of Sciences National Synchrotron Radiation Laboratory University of Science and Technology of China

Two-dimensional materials represent a major frontier for research into exotic many-body quantum phenomena. In the extreme two-dimensional limit, electron-electron interaction often dominates over other electronic energy scales, leading to strongly correlated effects such as quantum spin liquid and unconventional *** dominance is conventionally attributed to the lack of electron screening in the third dimension. Here, we discover an intriguing metal to Mott insulator transition in 1T-TaSe2that defies conventional wisdom. Specifically, we find that dimensionality crossover, instead of reduced screening, drives the transition in atomically thin 1T-TaSe2. A dispersive band crossing the Fermi level is found to be responsible for the bulk metallicity in the material. Reducing the dimensionality,however, effectively quenches the kinetic energy of these initially itinerant electrons, and drives the material into a Mott insulating *** dimensionality-driven metal to Mott insulator transition resolves the long-standing dichotomy between metallic bulk and insulating surface of 1T-TaSe2. Our work further reveals a new pathway for modulating two-dimensional materials that enables exploring strongly correlated systems across uncharted parameter space.

关键词： two-dimensional materials 1T-TaSe2 dimensionality crossover metal to Mott insulator transition

New sustainable polymers with on-demand depolymerization property

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Science China Chemistry 2024年第9期67卷 2803-2841页

作者： Yangyang Sun Zesheng An Yanshan Gao Rongrong Hu Ye Liu Hua Lu Xiao-Bing Lu xuan Pang Anjun Qin Yong Shen Youhua Tao Yu-Zhong Wang Junpeng Wang Gang Wu Guang-Peng Wu Tie-Qi Xu Xing-Hong Zhang Yuetao Zhang Zhenbiao Zhang Jian-Bo Zhu Miao Hong Zhibo Li State Key Laboratory of Organometallic Chemistry Shanghai Institute of Organic ChemistryChinese Academy of SciencesShanghai 200032China State Key Laboratory Base of Eco-Chemical Engineering College of Chemical EngineeringQingdao University of Science and TechnologyQingdao266042China State Key Laboratory of Supramolecular Structure and Materials College of ChemistryJilin UniversityChangchun 130012China State Key Laboratory of Luminescent Materials and Devices Guangdong Provincial Key Laboratory of Luminescence from Molecular AggregatesSouth China University of TechnologyGuangzhou 510640China State Key Laboratory of Fine Chemicals Frontiers Science Center for Smart MaterialsDalian University of TechnologyDalian 116024China Beijing National Laboratory for Molecular Sciences Center for Soft Matter Science and EngineeringKey Laboratory of Polymer Chemistry and Physics of Ministry of EducationCollege of Chemistry and Molecular EngineeringPeking UniversityBeijing 100871China Key Laboratory of Polymer Ecomaterials Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China The Collaborative Innovation Center for Eco-Friendly and Fire-Safety Polymeric Materials(MoE) National Engineering Laboratory of Eco-Friendly Polymeric Materials(Sichuan)College of ChemistryState Key Laboratory of Polymer Materials EngineeringSichuan UniversityChengdu 610064China School of Polymer Science and Polymer Engineering the University of AkronAkronOH 44325USA MOE Key Laboratory of Macromolecular Synthesis and Functionalization Department of Polymer Science and EngineeringZhejiang UniversityHangzhou 310027China State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials Jiangsu Key Laboratory of Advanced Functional Polymer Design and ApplicationSuzhou Key Laboratory of Macromolecular Design and Precision SynthesisCollege of ChemistryChemical Engineering and Materials ScienceSoochow UniversitySuzhou 215123China

To combat the crisis of today's synthetic polymers arising from unsustainable production and disposal,it is essential for the synthetic polymer community to reshape the current polymer industry with sustainable *** an emerging class of sustainable polymers,the development of chemically depolymerizable polymers(CDPs),which can undergo closed-loop depolymerization/repolymerization cycles to reproduce virgin polymers without the loss of properties from recovered monomers,offers an ideal solution to preserve finite natural resources,provides a feasible solution to the end-of-life issue of polymer waste,and thereby establishes a circular materials ***,two grand key challenges have been encountered in the establishment of practically useful CDPs:how to balance polymerization and depolymerization ability and how to unify conflicted depolymerizability and physical ***,this critical review article presents our vision for summarizing feasible strategies to overcome the above two significant challenges and the design principles for constructing an ideal CDP by highlighting selected major progress made in this rapidly expanding field.

关键词： chemically depolymerizable polymers sustainable polymers depolymerization monomer recovery degradation plastics

Alternate day fasting aggravates atherosclerosis through the suppression of hepatic ATF3 in Apoe^(-/-)mice

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Life Metabolism 2024年第3期3卷 46-59页

作者： Yajuan Deng Xiaoyu Yang Xueru Ye Youwen Yuan Yanan Zhang Fei Teng Danming You xuan Zhou Wenhui Liu Kangli Li Shenjian Luo Zhi Yang Ruxin Chen Guojun Shi Jin Li Huijie Zhang Department of Endocrinology and Metabolism Nanfang HospitalSouthern Medical UniversityGuangzhouGuangdong 510515China Guangdong Provincial Key Laboratory of Shock and Microcirculation Nanfang HospitalSouthern Medical UniversityGuangzhouGuangdong 510515China State Key Laboratory of Organ Failure Research National Clinical Research Center for Kidney DiseaseNanfang HospitalSouthern Medical UniversityGuangzhouGuangdong 510515China Department of Endocrinology The Second Hospital of Shanxi Medical UniversityShanxi Medical UniversityTaiyuanShanxi 030001China Department of Endocrinology and Metabolism Guangdong Provincial Key Laboratory of DiabetologyThe Third Affiliated Hospital of Sun Yat-sen UniversityGuangzhouGuangdong 510630China

Atherosclerosis is the major contributor to cardiovascular mortality *** day fasting(ADF)has gained growing attention due to its metabolic ***,the effects of ADF on atherosclerotic plaque formation remain inconsistent and controversial in atherosclerotic animal *** present study was designed to investigate the effects of ADF on atherosclerosis in apolipoprotein E-deficient(Apoe^(-/-))***-week-old male Apoe^(-/-)mice fed with Western diet(WD)were randomly grouped into ad libitum(AL)group and ADF group,and ADF aggravated both the early and advanced atherosclerotic lesion formation,which might be due to the disturbed cholesterol profiles caused by ADF *** significantly altered cholesterol metabolism pathways and down-regulated integrated stress response(ISR)in the *** hepatic expression of activating transcription factor 3(ATF3)was suppressed in mice treated with ADF and hepatocyte-specific overexpression of Aft3 attenuated the effects of ADF on atherosclerotic plaque formation in Apoe^(-/-)***,the expression of ATF3 could be regulated by Krüppel-like factor 6(KLF6)and both the expressions of ATF3 and KLF6 were regulated by hepatic cellular ISR *** conclusion,ADF aggravates atherosclerosis progression in Apoe^(-/-)mice fed on *** inhibits the hepatic ISR signaling pathway and decreases the expression of KLF6,subsequently inhibiting ATF3 *** suppressed ATF3 expression in the liver mediates the deteriorated effects of ADF on atherosclerosis in Apoe^(-/-)*** findings suggest the potentially harmful effects when ADF intervention is applied to the population at high risk of atherosclerosis.

关键词： alternate day fasting atherosclerosis cholesterol integrated stress response activating transcription factor 3

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“印太战略”视域下美国太平洋岛国政策论析

亚太经济 2024年第1期 108-119页

作者：丑则静郭晓萱国际关系学院国际政治系北京100091 南开大学周恩来政府管理学院天津300350

美国“印太战略”出台与全面强化后,太平洋岛国的战略价值被不断抬升。美国从安全、经济与意识形态多领域系统加强了对太平洋岛国的争夺,其政策体系趋于完善。在大国竞争回归背景下,中国在太平洋岛国地区的存在与影响力上升引发了美国... 详细信息

美国“印太战略”出台与全面强化后,太平洋岛国的战略价值被不断抬升。美国从安全、经济与意识形态多领域系统加强了对太平洋岛国的争夺,其政策体系趋于完善。在大国竞争回归背景下,中国在太平洋岛国地区的存在与影响力上升引发了美国等西方发达国家的战略焦虑,美国正将太平洋岛国视作“印太战略”与对华战略竞争的重点推进地区。然而,在“竞赢”中国、霸权护持战略目标支配下的美国太平洋岛国政策,表现出对地区和平稳定、发展繁荣及应对气候变化等核心关切的漠视,在导致太平洋岛国地区阵营化、大国竞争化与意识形态化风险上升的同时,其政策限度不断显现。

关键词： “印太战略” 美国太平洋岛国政策政策限度