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An inverse problem in film/substrate indentation:extracting both the Young's modulus and thickness of films

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Acta Mechanica Sinica 2018年第6期34卷 1061-1071页

作者： Yin Zhang Feifei Gao Zhiyue Zheng zhihai cheng State Key Laboratory of Nonlinear Mechanics(LNM) Institute of MechanicsChinese Academy of SciencesBeijing 100190China School of Engineering Science University of Chinese Academy of SciencesBeijing 100049China Department of Physics and Beijing Key Laboratory of Optoelectronic Functional Materials and Micro-Nano Devices Renmin University of ChinaBeijing 100872China

In an indentation test,the effective Young's modulus of a film/substrate bilayer heterostructure varies with the indentation depth,a phenomenon known as the substrate effect.In previous studies investigating this,only the Young's modulus of the film was unknown.Once the effective Young's modulus of a film/substrate structure is determined at a given contact depth,the Young's modulus of the film can be uniquely determined,i.e.,there is a one-to-one relation between the Young's modulus of the film and the film/substrate effective Young's modulus.However,at times it is extremely challenging or even impossible to measure the film thickness.Furthermore,the precise definition of the layer/film thickness for a two-dimensional material can be problematic.In the current study,therefore,the thickness of the film and its Young's modulus are treated as two unknowns that must be determined.Unlike the case with one unknown,there are infinite combinations of film thickness and Young's modulus which can yield the same effective Young's modulus for the film/substrate.An inverse problem is formulated and solved to extract the Young's modulus and thickness of the film from the indentation depth-load curve.The accuracy and robustness of the inverse problem-solving method are also demonstrated.

关键词： Indentation test Film Substrate Inverse problem

Advanced atomic force microscopies and their applications in two-dimensional materials:a review

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Materials Futures 2022年第3期1卷 105-143页

作者： Rui Xu Jianfeng Guo Shuo Mi Huanfei Wen Fei Pang Wei Ji zhihai cheng Beijing Key Laboratory of Optoelectronic Functional Materials&Micro-nano Devices Department of PhysicsRenmin University of ChinaBeijing 100872People’s Republic of China Key Laboratory of Instrument Science and Dynamic Testing North University of ChinaTaiyuan 030051People’s Republic of China Key Laboratory of Quantum Sensing and Precision Measurement Institute of Instrument and ElectronicsNorth University of ChinaTaiyuan 030051People’s Republic of China

Scanning probe microscopy(SPM)allows the spatial imaging,measurement,and manipulation of nano and atomic scale surfaces in real space.In the last two decades,numerous advanced and functional SPM methods,particularly atomic force microscopy(AFM),have been developed and applied in various research fields,from mapping sample morphology to measuring physical properties.Herein,we review the recent progress in functional AFM methods and their applications in studies of two-dimensional(2D)materials,particularly their interfacial physical properties on the substrates.This review can inspire more exciting application works using advanced AFM modes in the 2D and functional materials fields.

关键词： atomic force microscopy advanced atomic force microscopy two-dimensional materials surface and interface

Local electrical charac terization of t wo-dimensional mat erials with functional atomic force microscopy

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Frontiers of physics 2019年第3期14卷 85-105页

作者： Sabir Hussain Kunqi Xu Shili Ye Le Lei Xinmeng Liu Rui Xu Liming Xie zhihai cheng CAS Key Laboratory of Standardization and Measurement for Nanotechnology CAS Center for Excellence in Nanoscience National Center for Nanoscience and Technology Beijing 100190 China Department of Physics and Beijing Key Laboratory of Optoelectronic Functional Materials & Micro-nano Devices Renmin University of China Beijing 100872 China University of Chinese Academy of Sciences Beijing 100049 China

Research about two-dimensional (2D) materials is growing exponentially across various scientific and engineering disciplines due to the wealth of unusual physical phenomena that occur when charge transport is confined to a plane. The applications of 2D materials are highly affected by the electrical properties of these mat erials, including curren t dist ribution, surface pot ential, dielectric response, conductivity, perm计tivity, and piezoelectric response. Hence, it is very crucial to characterize these properties at the nanoscale. The Atomic Force Microscopy (AFM)-based techniques are powerful tools that can simultaneously characterize morphology and electrical properties of 2D materials with high spatial resolution, thus being more and more extensively used in this research field. Here, the principles of these AFM techniques are reviewed in detail. After that, their representative applications are further demonstrated in the local characterization of various 2D materials? elcctrical properties.

关键词： advanced AFM techniques nanoscale characteTization electrical properties 2D materials

Direct Imaging of Molecular Orbitals of Metal Phthalocyanines on Metal Surfaces with an O2-Functionalized Tip of a Scanning Tunneling Microscope

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Nano Research 2011年第6期4卷 523-530页

作者： zhihai cheng Shixuan Du Wei Guo Li Gao Zhitao Deng Nan Jiang Haiming Guo Hao Tang H. J. Gao Institute of Physics Chinese Academy of Sciences RO. Box 603 Beijing 100190 China Center for Material Elaboration and Structural Studies B.P. 94347 31055 Toulouse Cedex France

Au (111 ) 上的铁酞毒和锌酞毒分子的高分辨率的扫描通道显微镜图象用一台扫描通道显微镜(STM ) 的一个 functionalized 尖端被获得了，并且显示出没用干净尖端被观察的富有的 intramolecular 特征。Ab initio 密度功能的理论计算和扩... 详细信息

Au (111 ) 上的铁酞毒和锌酞毒分子的高分辨率的扫描通道显微镜图象用一台扫描通道显微镜(STM ) 的一个 functionalized 尖端被获得了，并且显示出没用干净尖端被观察的富有的 intramolecular 特征。Ab initio 密度功能的理论计算和扩大 H？

关键词：扫描隧道显微镜分子轨道金属酞菁氧分子金属表面成像密度泛函理论轨道相互作用

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燃煤锅炉氨煤混燃技术的研究进展

化工环保 2024年第3期44卷 345-352页

作者：王宁泽李芳芹潘卫国程智海官贞珍上海电力大学能源与机械工程学院上海200090

为了应对全球气候变化,实现“碳达峰、碳中和”目标,减少碳排放至关重要。氨气具有运输储存成本低、安全性高、燃烧零碳排放等优势,燃煤锅炉氨煤混燃技术受到全社会的高度重视。本文综述了燃煤电厂的低碳低氮燃烧工艺,介绍了氨气燃料的... 详细信息

为了应对全球气候变化,实现“碳达峰、碳中和”目标,减少碳排放至关重要。氨气具有运输储存成本低、安全性高、燃烧零碳排放等优势,燃煤锅炉氨煤混燃技术受到全社会的高度重视。本文综述了燃煤电厂的低碳低氮燃烧工艺,介绍了氨气燃料的火焰传播特性,从氨气注入位置、氨气掺混比、燃尽风、当量比等多个角度分析了氨煤混燃技术对NOx生成量的影响,探讨了氨煤混燃对燃煤机组性能的影响,指出氨煤混燃技术是极具发展潜力的低碳燃烧技术,对于我国实现“双碳”目标具有重要意义。

关键词：燃煤锅炉氨煤混燃燃烧特性 NOx排放

Tuning the morphology of chevron-type graphene nanoribbons by choice of annealing temperature

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Nano Research 2018年第12期11卷 6190-6196页

作者： Yun Cao Jing Qi Yan-Fang Zhang Li Huang Qi Zheng Xiao Lin zhihai cheng Yu-Yang Zhang Xinliang Feng Shixuan Du Sokrates T.Pantelides Hong-Jun Gao Institute of Physics &University of Chinese Academy of Sdences Chinese Academy ofSdencesBeijing 100190China Department of Physics Renmin University of ChinaBeijing 100872China Department of Physics and Astronomy and Department of Electrical Engineering and Computer Science Vanderbilt UniversityNashvilleTennessee 37235USA Center for Advancing Electronics Dresden (cfaed)&Department of Chemistry and Food Chembtry Technische Universitat DresdenD-O 1069DresdenGermany School of Chemistry and Chemical Engineering Shanghai jiao Tong UniversityShanghai200240China

Bottom-up synthesis of graphene nanoribbons (GNRs) by surface-assisted polymerization and cyclodehydrogenation of specifically designed precursor monomers has been shown to yield precise edges and doping. Here we use a precursor monomer containing sulfur atoms to fabricate nanostructures on a Au(111) surface at different annealing temperatures. The nanostructures have distinct configurations, varying from sulfur-doped polymers to sulfur-doped chevron-type GNRs (CGNRs) and, finally, pristine graphene nanoribbons with specific edges of periodic five-member carbon rings. Non-contact atomic force microscopy provides clear evidence for the cleavage of C–S bonds and formation of pristine CGNRs at elevated annealing temperatures. First-principles calculations show that the CGNRs exhibit negative differential resistance.

关键词： chevron-type graphene nanoribbon C–S bond cleavage negative differential resistance scanning tunneling microscopy (STM) noncontact atomic force microscopy (NC-AFM) first-principles calculations

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电厂送粉管道偏差影响因素数值模拟分析

上海节能 2024年第6期 1000-1005页

作者：孙康程智海娄中发王之武上海电力大学

电厂送粉管道偏差对锅炉燃烧的稳定性、锅炉运行的安全性和经济性、火力发电机组运行的灵活性等都有着十分重要的影响。为了深入探究送粉管道入口的煤粉细度变化和煤粉浓度变化对送粉管道出口偏差的影响规律,以某电厂直吹式制粉系统中的... 详细信息

电厂送粉管道偏差对锅炉燃烧的稳定性、锅炉运行的安全性和经济性、火力发电机组运行的灵活性等都有着十分重要的影响。为了深入探究送粉管道入口的煤粉细度变化和煤粉浓度变化对送粉管道出口偏差的影响规律,以某电厂直吹式制粉系统中的B磨煤机所对应的送粉管道为研究对象,利用求解器软件ANSYS Fluent对送粉管道进行了数值模拟计算。结果表明,随着管道入口煤粉细度的增加,各送粉管道出口风速(煤粉浓度)偏差变化不明显;随着管道入口煤粉浓度的增加,各个送粉管道出口风速(煤粉浓度)偏差均逐渐降低,管道出口风速(煤粉浓度)最大偏差显著降低。通过对送粉管道偏差影响因素的数值模拟,可知送粉管道入口煤粉细度对管道出口偏差没有影响,而送粉管道入口煤粉浓度增加有助于降低管道出口偏差。

关键词：送粉管道偏差煤粉细度煤粉浓度数值模拟

Epitaxial fabrication of AgTe monolayer on Ag(111)and the sequential growth of Te film

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Frontiers of physics 2021年第6期16卷 125-131页

作者： Haoyu Dong Le Lei Shuya Xing Jianfeng Guo Feiyue Cao Shangzhi Gu Yanyan Geng Shuo Mi Hanxiang Wu Yan Jun Li Yasuhiro Sugawara Fei Pang Wei Ji Rui Xu zhihai cheng Beijing Key Laboratory of Optoelectronic Functional Materials&Micro-nano Devices Department of PhysicsRenmin University of ChinaBeijing 100872China Department of Applied Physics Graduate School of EngineeringOsaka University2-1 YamadaokaSuitaOsaka 565-0871Japan

Transition-metal chalcogenides(TMCs)materials have attracted increasing interest both for fundamental research and industrial applications.Among all these materials,two-dimensional(2D)compounds with honeycomb-like structure possess exotic electronic structures.Here,we report a systematic study of TMC monolayer AgTe fabricated by direct depositing Te on the surface of Ag(111)and annealing.Few intrinsic defects are observed and studied by scanning tunneling microscopy,indicating that there are two kinds of AgTe domains and they can form gliding twin-boundary.Then,the monolayer AgTe can serve as the template for the following growth of Te film.Meanwhile,some Te atoms are observed in the form of chains on the top of the bottom Te film.Our findings in this work might provide insightful guide for the epitaxial growth of 2D materials for study of novel physical properties and for future quantum devices.

关键词： AgTe monolayer Te film epitaxial growth scanning tunneling microscopy two-dimensional materials transition-metal chalcogenides

Toplayer-dependent crystallographic orientation imaging in the bilayer two-dimensional materials with transverse shear microscopy

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Frontiers of physics 2021年第5期16卷 165-172页

作者： Sabir Hussain Rui Xu Kunqi Xu Le Lei Shuya Xing Jianfeng Guo Haoyu Dong Adeel Liaqat Rashid Iqbal Muhammad Ahsan Iqbal Shangzhi Gu Feiyue Cao Yan Jun Li Yasuhiro Sugawara Fei Pang Wei Ji Liming Xie Shanshan Chen zhihai cheng Beijing Key Laboratory of Optoelectronic Functional Materials&Micro-nano Devices Department of PhysicsRenmin University of ChinaBeijing100872China CAS Key Laboratory of Standardization and Measurement for Nanotechnology CAS Center for Excellence in NanoscienceNational Center for Nanoscience and TechnologyBeijing100190China Key Laboratory of Inorganic Functional Materials and Devices Shanghai Institute of CeramicsChinese Academy of SciencesShanghai200050China University of Chinese Academy of Sciences Beijing100039China Department of Applied Physics Graduate School of EngineeringOsaka University2-1 YamadaokaSuitaOsaka565-0871Japan

Nanocontact properties of two-dimensional(2D)materials are closely dependent on their unique nanomechanical systems,such as the number of atomic layers and the supporting substrate.Here,we report a direct observation of toplayer-dependent crystallographic orientation imaging of 2D materials with the transverse shear microscopy(TSM).Three typical nanomechanical systems,MoS_(2) on the amorphous SiO_(2)/Si,graphene on the amorphous SiO_(2)/Si,and MoS_(2) on the crystallized Al_(2)O_(3),have been investigated in detail.This experimental observation reveals that puckering behaviour mainly occurs on the top layer of 2D materials,which is attributed to its direct contact adhesion with the AFM tip.Furthermore,the result of crystallographic orientation imaging of MoS_(2)/SiO_(2)/Si and MoS_(2)/Al_(2)O_(3) indicated that the underlying crystalline substrates almost do not contribute to the puckering effect of 2D materials.Our work directly revealed the top layer dependent puckering properties of 2D material,and demonstrate the general applications of TSM in the bilayer 2D systems.

关键词： 2D materials toplayer-dependent crystallographic orientation imaging nanomechanical contact properties transverse shear microscopy