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Electric field controlled superlubricity of fullerene-based host–guest assembly

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Nano Research 2023年第1期16卷 583-588页

作者： Shanchao Tan hongyu shi Xin Du Kunpeng Wang Haijun Xu Junhua Wan Ke Deng Qingdao Zeng Yuhong Liu State Key Laboratory of Tribology Tsinghua UniversityBeijing 100084China CAS Key Laboratory of Standardization and Measurement for Nanotechnology CAS Center for Excellence in NanoscienceNational Center for Nanoscience and Technology(NCNST)Beijing 100190China College of Chemical Engineering Jiangsu Key Lab of Biomass-based Green Fuels and ChemicalsNanjing Forestry UniversityNanjing 210037China Key Laboratory of Organosilicon Chemistry and Material Technology of Ministry of Education Hangzhou Normal UniversityHangzhou 310012China Center of Materials Science and Optoelectonics Engineering University of Chinese Academy of SciencesBeijing 100049China

Controlling friction by the electric field is a promising way to improve the tribological performance of a variety of movable mechanical systems.In this work,the assembly structure and microscale superlubricity of a host–guest assembly are effectively controlled by the electric field.With the help of the scanning tunneling microscopy(STM)technique,the host–guest assembly structures constructed by the co-assembly of fullerene derivative(Fluorene-C60)with macrocycles(4B2A and 3B2A)are explicitly characterized.Combined with density functional theory(DFT),the distinct different assembly behaviors of fullerene derivatives are revealed at different probe biases,which is attributed to the molecular polarity of the fullerene derivative.Through the control on the adsorption behavior,the friction coefficient of host–guest assembly is demonstrated to be controllable in the electric field by using atomic force microscopy(AFM).At positive probe bias,the friction coefficient of the host–guest assembly is significantly reduced and achieves superlubricity(μmin=0.0049).The efforts not only help us gain insight into the host–guest assembly mechanism controlled by the electric field,but also promote the further application of fullerene in micro-electro-mechanical systems(MEMS).

关键词： superlubricity electric field friction control fullerene derivative host-guest assembly

Transmissive metasurface for multi-channel and full-polarization modulation of electromagnetic wavefronts

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Photonics Research 2023年第2期11卷 245-251页

作者： LINDA SHAO ZHENFEI LI JIALIN FENG JIN ZHANG hongyu shi XUDONG BAI WEIREN ZHU Department of Electronic Engineering Shanghai Jiao Tong UniversityShanghai 200240China School of Information and Communications Engineering Xi’an Jiaotong UniversityXi’an 710049China School of Microelectronics Northwestern Polytechnical UniversityTaicang 215400China

Metasurfaces have great potential for flexible manipulation of electromagnetic wave polarizations and wavefronts.Here, we propose a general method for achieving independent wavefront manipulation in a single polarizationmultiplexing transmissive metasurface. As a proof of concept, we design a transmission-type anisotropic metasurface for independent wavefront manipulation in full-polarization channels. An x-polarized wave transmitted through such a metasurface could be converted into four outgoing beams with delicately designed polarization states that converge to specific positions for holographic imaging. The measured results are in good agreements with simulated ones, verifying the independent wavefront manipulations with arbitrary polarization conversions.Compared with the existing traditional meta-devices with single-polarization modulation, we achieve polarization-multiplexed metasurfaces with mixed polarization and phase control, which can greatly improve the functional richness of the system.

关键词： surface. proof holographic

An annually laminated stalagmite from the eastern Qinghai-Tibetan Plateau provides evidence of climate instability during the early MIS5e in the Asian summer monsoon

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Science China Earth Sciences 2023年第5期66卷 1147-1164页

作者： Tao GAO Pingzhong ZHANG Hai CHENG Leilei ZHANG Xinhu LI hongyu shi Wei JIA Youfeng NING Hanying LI R.Lawrence EDWARDS Key Laboratory of Mineral Resources in Western China(Gansu Province)and School of Earth Sciences Lanzhou UniversityLanzhou730000China Institute of Global Environmental Change Xi’an Jiaotong UniversityXi’an710054China Department of Earth Sciences University of MinnesotaMinneapolis55455USA

The Marine Isotope Stage(MIS5e)is characterized by a warmer climate than that of the pre-industrial period,and serves as an analog for the Current Warm Period(CWP).However,uncertainties persist regarding its climatic stability.Here,we retrieved a stalagmite(WXB075)from Wanxiang Cave in the eastern Qinghai-Tibetan Plateau,and employed abs-olute^(230)Th dating and relative annual layer data to establish a high-precision chronological framework for reconstructing the history of the Asian summer monsoon(ASM)and environmental evolution during early MIS5e with multiple proxies.The findings indicate that the annually laminated stalagmite was formed during Cooling Event 27(C27).The deposition of WXB075 experienced a hiatus(~125.58 ka BP)due to a significant cooling event in the North Atlantic,which may be linked to the unstable climate in the Northern Hemisphere.Additionally,the impact of meltwater discharge in high northern latitudes results in a two-phase evolution of the ASM,i.e.,an initial weaker stage followed by a gradual increase(with exception of deposition hiatus).The climatic instability of ASM is generally characterized by a quasi-60 year cycle that affects vegetation conditions,biological productivity,and karst hydroclimate dynamics.However,the increase in meltwater and decrease in temperature in the Northern Hemisphere have led to a weakened ASM and subsequent reduction in precipitation.Consequently,vegetation degradation above the cave has occurred along with a slowdown of karst hydroclimate.The vegetation conditions,organic matter content,and wet/drought of the karst hydroclimate were affected by both the large-scale monsoon circulation and local environment during extreme weakening(strengthening)of the monsoon when high-frequency climatic events of ASM occurred.A comparison ofδ^(18)O records between early MIS5e and the past 2000 years reveals that the climate during early MIS5e differed significantly from that of CWP,Medieval Warm Period(MWP),and Dark Age Cold Period(DACP)but was similar to Little Ice Age

关键词： Eastern Qinghai-Tibetan Plateau Climate instability Wanxiang Cave stalagmite Asian summer monsoon Environmental response Deposition hiatus

法人财产权维护与公司可持续发展——基于财务的视角

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财务研究 2024年第2期 3-11页

作者：谢志华王佳丽史洪玉北京工商大学商学院新疆科技学院会计学院

公司的产生形成了法人,所有者投入公司的财产也就成为法人财产,公司对法人财产享有占有、使用、收益和处分的权利,并以此对外承担责任。法人财产是公司设立的前提,也是公司经营以及可持续发展的物质基础,公司必须要充分有效地维护法人... 详细信息

公司的产生形成了法人,所有者投入公司的财产也就成为法人财产,公司对法人财产享有占有、使用、收益和处分的权利,并以此对外承担责任。法人财产是公司设立的前提,也是公司经营以及可持续发展的物质基础,公司必须要充分有效地维护法人财产权。公司的可持续发展既依赖于法人财产的安全完整和权利的维护,也是其根本的保障。法人财产权的维护与财务有着天然的联系,公司可以通过财务的方式实现法人财产权的维护,进而使公司持续稳定发展。财务实现方式包括:明确界定出资权与经营权边界、确保一切业务都能创造价值、明确划定公司与政府和社会的成本边界、实现合理竞争和公平交易、选择资金合理留存公司的会计政策,以及控制资产变现风险。

关键词：法人财产权高质量发展可持续发展财务实现方式

Cross-polarization suppression in C-shaped microstrip patch antenna employing anisotropic dielectrics

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Journal of Advanced Dielectrics 2017年第4期7卷 29-33页

作者： hongyu shi shitao Zhu Jianxing Li Anxue Zhang Zhuo Xu School of Electronic and Information Engineering Xi'an Jiaotong University Xi'anShaanxi 710049P.R.China Electronic Materials Research Laboratory and the Key Laboratory of the Ministry of Education Xi'an Jiaotong University Xi'anShaanxi 710049P.R.China

An anisotropic dielectric realized by layered ceramic structures was adopted to design a low cross-polarization C-shaped patch antenna.The anisotropic dielectric performs as a substrate and can cause additional cross-polarized fields which are able to cancel the cross-polarized fields generated by the C-shaped patch itself,and then reduce the cross-polarization level.Compared to the C-shaped patch antenna with an isotropic substrate,the cross-polarization of the proposed antenna is suppressed by more than 15 dB with a little gain enhancement at 2.4 GHz.The anisotropic dielectric has a little impact on the direction of the C-shaped patch antenna.The gain of the proposed C-shaped patch antenna is 6.8 dB with a cross-polarization of28 dB.

关键词： Anisotropic dielectrics layered ceramic structures low cross-polarization patch antennas

2D-to-3D buckling transformability enabled reconfigurable metamaterials for tunable chirality and focusing effect

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Photonics Research 2023年第10期11卷 1770-1780页

作者： DONGHAI HAN WENKANG LI TAO SUN MIN LIU XIAOMING CHEN hongyu shi ZHENGJIE FAN FANQI MENG LIUYANG ZHANG XUEFENG CHEN State Key Laboratory for Manufacturing Systems Engineering Xi’an Jiaotong UniversityXi’an 710049China School of Information and Communications Engineering Xi’an Jiaotong UniversityXi’an 710049China Physikalisches Institut Goethe-Universität60438 Frankfurt am MainGermany

Recently,multifarious deformation approaches in nature have promoted dynamic manipulation for electromagnetic(EM)waves in metamaterials,and those representative strategies are mainly focused on the modulation of spectral parameters.Several works have also achieved tunable phase-gradient meta-devices.Here,to broaden the modulation freedom of mechanical deformation,we initially propose two reconfigurable metamaterials consisting of mirrored S-shaped meta-atoms selectively bonded on biaxially pre-stretched substrates.Planar meta-atoms with spin-insensitive transmittance are buckled into 3D morphologies to break residual symmetries by releasing the stress and to facilitate spin-dependent transmittance under circularly polarized incidence.Owing to the geometric anisotropy of S-shaped meta-atoms along the x and y axes,3D chiral meta-atoms exhibit discriminate circularly cross-polarized transmittance under opposite spins.The underlying physical mechanism reveals that EM resonance originates from the excitation of electric dipoles and magnetic dipoles,and their cross coupling finally triggers the chiral effects of 3D meta-atoms.By introducing the gradient-phase design that keeps unchanged under various strains,two types of meta-atoms with specified orientations are interleaved to design a double-foci metalens,and its 2D-to-3D morphology transformation shortens the focusing length and facilitates the intensity change of two foci.Our approach in designing reconfigurable EM metamaterials with 2D-to-3D buckling transformability can be further extended toward terahertz even optical wavebands,and it may assist with deriving more applicable multi-functionalities in the aspects of imaging,sensing,and holograms.

关键词： buckling polarized circular

Influence of functional groups on the self-assembly of liquid crystals

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Chinese Chemical Letters 2021年第3期32卷 1149-1152页

作者： Shanchao Tan Jiayu Tao Wendi Luo Hao Jiang Yuhong Liu Haijun Xu Qjngdao Zeng hongyu shi State Key Laboratory of Tribology Tsinghua UniversityBeijing 100084China CAS Key Laboratory of Standardization and Measurement for Nanotechnology CAS Center for Excellence in NanoscienceNational Center for Nanoscience and Technology(NCNST)Beijing 100190China Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources College of Chemical EngineeringNanjing Forestry UniversityNanjing 210037China Laboratory of Theoretical and Computational Nanoscience CAS Center for Excellence in NanoscienceNational Center for Nanoscience and TechnologyBeijing 100190China Center of Materials Science and Optoelectonics Engineering University of Chinese Academy of SciencesBeijing 100049China Sino-Danish Center for Education and Research University of Chinese Academy of SciencesBeijing 100190China

Functional groups in the molecule play an important role in the molecular o rganization process.To reveal the influence of functional groups on the self-assembly at interface,herein,the self-assembly structures of three liquid crystal molecules,which only differ in the functional groups,are explicitly characterized by using scanning tunneling microscopy(STM).The high-resolution STM images demonstrate the difference between the supramolecular assembly structures of three liquid crystal molecules,which attribute to the hydrogen bonding interaction andπ-πstacking interaction between different functional groups.The density functional theory(DFT)results also confirm the influence of these functional groups on the self-assemblies.The effort on the self-assembly of liquid crystal molecules at interface could enhance the understanding of the supramolecular assembly mechanism and benefit the further application of liquid crystals.

关键词： Self-assembly Liquid crystal Functional group Hydrogen bond π-πStacking interaction

译者主体性视角下级差资源“更”的重构研究——以《习近平谈治国理政》日译本为例

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东北亚外语研究 2024年第2期12卷 94-106,129页

作者：孙成志史洪煜大连理工大学外国语学院辽宁大连116024

在中央文献翻译过程中,如何实现级差资源的评价意义重构,集中彰显了译者的翻译立场。本研究基于《习近平谈治国理政》(第一卷至第三卷)中日对译文本,从译者主体性视角探析级差资源“更”在中央文献日译过程中的重构方式及其背后的成因... 详细信息

在中央文献翻译过程中,如何实现级差资源的评价意义重构,集中彰显了译者的翻译立场。本研究基于《习近平谈治国理政》(第一卷至第三卷)中日对译文本,从译者主体性视角探析级差资源“更”在中央文献日译过程中的重构方式及其背后的成因。研究发现:级差资源的跨语际重构在三卷中呈现出一定的历时一致性,当“更”用于提升后文评价意义的“强度”时,译者更倾向于采用零翻译,以合译、扩大语言单位等方式重构级差资源;而当“更”用于提升后文评价意义“量度”时,译者通常选择对应翻译,保留原文的级差资源。同时,译者在不同语势功能下,受语言单位、句式等客观受动性制约,适时调整翻译方式;在维护国家形象、增强意识形态意义表征等社会语境下,充分发挥其主观能动性,重构级差资源的评价意义,以此增进目标读者的理解与接受度,提升对外话语的创造力、感召力和公信力。

关键词：译者主体性级差资源“更” 《习近平谈治国理政》中央文献翻译跨语际重构

Research Status and Key Technologies of Geo-Electromagnetic Magnetic Induction Sensor

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Journal of Harbin Institute of Technology(New Series) 2017年第4期24卷 38-49页

作者： Yanzhang Wang Yunxia Wan Chen Chen hongyu shi Jun Lin Defu Cheng Key Laboratory of Geo-Exploration Instrumentation Ministry of EducationJilin University College of Instrumentation & Electrical Engineering Jilin University

According to different applications,the performance parameters of the several Geo-Electromagnetic Magnetic Induction Sensors( GEMISs) which are the most representative in the world are compared. After discussing the several key technologies for improving the performance of GEMISs,the main conclusions are as follows: the application bandwidth can be expanded by adopting flux negative feedback( 1 m Hz-10 k Hz);"laminated"core structure is useful for suppressing eddy current loss; the effective permeability of the core has increased observably after adding flux concentrators to the two ends of the core; the chopper amplifier is a useful method to suppress 1/f noise for reducing the GEMIS's output noise; the indoor calibration scheme based on"long straight solenoid"proposed to obtain sensor sensitivity. Accordingly,the problem how to reduce the noise of GEMIS is urgent need to be solved,which will improve the performance of GEMIS. And there is plenty of work requires further study on parameters ' optimization of coil and core. In the future,miniaturization,intelligence and three-axis measurement are the development directions of GEMIS.

关键词： GEMIS key technologies flux negative feedback “Laminated” corestructure flux concentrators