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Ion energy-induced nanoclustering structure in a-C:H film for achieving robust superlubricity in vacuum

Friction 2022年第12期10卷 1967-1984页

作者： Qingyuan YU Xinchun CHEN Chenhui ZHANG Chenxi ZHANG Wenli DENG Yinhui WANG jianxun xu Wei QI State Key Laboratory of Tribology Tsinghua UniversityBeijing 100084China

Hydrogenated amorphous carbon(a-C:H)films are capable of providing excellent superlubricating properties,which have great potential serving as self-lubricating protective layer for mechanical systems in extreme working conditions.However,it is still a huge challenge to develop a-C:H films capable of achieving robust superlubricity state in vacuum.The main obstacle derives from the lack of knowledge on the influencing mechanism of deposition parameters on the films bonding structure and its relation to their self-lubrication performance.Aiming at finding the optimized deposition energy and revealing its influencing mechanism on superlubricity,a series of highly-hydrogenated a-C:H films were synthesized with appropriate ion energy,and systematic tribological experiments and structural characterization were conducted.The results highlight the pivotal role of ion energy on film composition,nanoclustering structure,and bonding state,which determine mechanical properties of highly-hydrogenated a-C:H films and surface passivation ability and hence their superlubricity performance in vacuum.The optimized superlubricity performance with the lowest friction coefficient of 0.006 coupled with the lowest wear rate emerges when the carbon ion energy is just beyond the penetration threshold of subplantation.The combined growth process of surface chemisorption and subsurface implantation is the key for a-C:H films to acquire stiff nanoclustering network and high volume of hydrogen incorporation,which enables a robust near-frictionless sliding surface.These findings can provide a guidance towards a more effective manipulation of self-lubricating a-C:H films for space application.

关键词： hydrogenated amorphous carbon(a-C:H) superlubricity ion energy nanoclustering bonding structure mechanical properties

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Analytical methods for nano-bio interface interactions

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Science China Chemistry 2016年第11期59卷 1467-1478页

作者： Jing Wang Waseem Akthar Quershi Yiye Li jianxun xu Guangjun Nie CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety CAS Center for Excellence in NanoscienceNational Center for Nanoscience and Technology

Knowledge on the interactions between engineered nanomaterials(ENMs) and biological systems is critical both for the assessment of biological effects of ENMs and for the rational design of ENM-based products. However, probing the events that occur at the nano-bio interface remains extremely challenging due to their complex and dynamic nature. So far, the understanding of mechanisms underlying nano-bio interactions has been mainly limited by the lack of proper analytical techniques with sufficient sensitivity, selectivity and resolution for characterization of nano-bio interface events. Moreover, many classic bioanalytical methods are not suitable for direct measurement of nano-bio interface interactions. These have made establishing analytical methodologies for systematic and comprehensive study of nano-bio interface one of the most focused areas in nanobiology. In this review we have discussed some representative developments regarding analytical techniques for nano-bio interface characterization, including the improvements of traditional methods and the emergence of powerful new technologies. These developments have allowed ultrasensitive, real-time analysis of interactions between ENMs and biomolecules, transformations of ENMs in biological environment, and impacts of ENMs on living systems on molecular or cellular level.

关键词：设计 nanomaterial nano 简历接口 nano 简历相互作用分析方法蛋白质日冕同步加速器放射

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Novel multiferroicity in orthorhombic SmCrO3

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Progress in Natural Science:Materials International 2018年第5期28卷 609-613页

作者： Zhongcheng Xiang jianxun xu Yunxia Huang Shuaipeng Ge Yimin Cui Key Laboratory of Micro-nano Measurement-Manipulation and Physics (Ministry of Education) Department of Physics Beihang University State Key Laboratory of Tribology Tsinghua University

This paper reports the ferroelectricity in antiferromagnetic SmCrO3with a reasonably large value of spontaneous electric polarization(70μC/cm~2mC cm-2at 50 K)based on the measurement of pyroelectric current.The experimental results showed that the temperature of the onset of polar order was evidently higher(about220 K)than the Neel temperature(TN=197 K)in the magnetodielectric studies.The calculated magnetodielectric effect(MDE)value was explicitly negative with maximum|MDE|values of about 3.6%around 230 K.The absence of a convincing signature in MDE at antiferromagnetic ordering temperature TNindicated the absence of magnetoelectric coupling around this temperature regime.The results further confirmed that the onset of polar order can be attributed to the structural distortion,rather than the canted noncollinear magnetic structure.

关键词： Cr Novel multiferroicity in orthorhombic SmCrO3 MDE

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Improvements of dielectric properties of Cu doped LaTiO3+δ

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Progress in Natural Science:Materials International 2016年第2期26卷 158-162页

作者： Yan Chen jianxun xu Yimin Cui Guangyi Shang Jianqiang Qian Jun-en Yao Key Laboratory of Micro-nano Measurement-Manipulation and Physics Ministry of Education Beihang University School of Physics and Nuclear Energy Engineering Beihang University School of Instrumentation Science and Opto-electronics Engineering Beihang University

The ceramic composites of Cu-doped La;Cu;TiO;（x=0.05, 0.15, 0.3, 0.5） were synthesized by conventional solid-state reaction. The complex dielectric properties of the composites were investigated as a function of temperature（77 K ≤T≤ 320 K） and frequency（100 Hz ≤ f ≤1 MHz） separately. In all composites, the dielectric constants increase monotonously and the dielectric loss undulates with temperature. And it is clearly observed that extraordinarily high low-frequency dielectric constant（～10;）appear at room temperature in La;.5Cu;.5TiO;, which is 100 times larger than that of La;.95Cu;.05 TiO;. Interestingly, the dielectric constants increase remarkably with the doped Cu contents, meanwhile the dielectric loss for all samples is ideal lower than 1 at room temperature in the measured frequency range. By means of complex impedance analysis, the improvements of dielectric properties are attributed to both bulk contribution and grain boundary effect, in which the bulk polaronic relaxation and the Maxwell–Wagner relaxation due to grain boundary response are heightened remarkably with the high doped Cu contents.

关键词： Cu doped LaTiO3+δ Dielectric properties Complex impedance

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10kV配网架空线路运维检修带电作业分析

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电力设备管理 2024年第9期 204-206页

作者：韦向阳徐健勋国网阜宁县供电公司国网射阳县供电公司

随着我国城市化进程的加快电力需求不断增长,同时10kV配网架空线缆的负荷也在不断上升。为确保电能稳定供应和线缆正常运行,常采用带电作业模式检修线路。然而,受多种因素影响带电作业危险性高且复杂。为提高带电作业的安全性,本文将建... 详细信息

随着我国城市化进程的加快电力需求不断增长,同时10kV配网架空线缆的负荷也在不断上升。为确保电能稳定供应和线缆正常运行,常采用带电作业模式检修线路。然而,受多种因素影响带电作业危险性高且复杂。为提高带电作业的安全性,本文将建立科学的评价标准,分析影响带电作业安全的相关因素,以提升作业安全。本文重点对带电作业的安全性综合评价标准,以配电箱架空线路带电作业的保护措施为讨论核心。

关键词：配电架空线路运维检修带电作业

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Veratrilla baillonii Franch alleviate the symptoms of diabetes in type 2 diabetic rats induced by high-fat diet and streptozotocin

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Food Science and Human Wellness 2024年第3期13卷 1378-1389页

作者： Chunlan Yan Zhihao Zhang Liqun Ma Xinyi xu Muhammad Azhar Xianju Huang jianxun Shi Jun Li College of Life Sciences South-Central Minzu UniversityWuhan 430074China College of Pharmaceutical Science South-Central Minzu UniversityWuhan 430074China Department of Biosciences COMSATS University IslamabadSahiwal 57000Pakistan Zhejiang Pharmaceutical University Ningbo 315100China Ethnopharmacology Level 3 Laboratory National Administration of Traditional Chinese MedicineSouth-Central Minzu UniversityWuhan 430074China

Our previous research studies have shown that Veratrilla baillonii Franch,a food supplement used by ethnic minorities in Southwest China,has multiple pharmacological activities,such as detoxification,antiinflammatory,antioxidant,and anti-insulin resistance.However,the detailed signal pathways for its salutary effect on damages in multiple organs due to type 2 diabetes mellitus(T2DM)remains unclear.The current study is to evaluate the therapeutic effects of V.baillonii on T2DM rats and to explore the underlying mechanisms.The T2DM rat model was successfully established by a high-sugar and high-fat diet(HFD)combination with intraperitoneal injection of a small dose of streptozotocin(STZ,35 mg/kg).Biochemical analysis and histopatholgical examinations were conducted to evaluate the anti-diabetic potential of water extracts of V.baillonii(WVBF).The results showed that the WVBF treatment can improve hyperglycemia and insulin resistance,ameliorate the liver,kidney and pancreas injuries via decreasing inflammatory cytokines such as IL-6 and TNF-α,and oxidative damages.Further investigation suggested that WVBF modulates the signal transductions of the IRS1/PI3K/AKT/GLUT4 and AMPK pathways.These findings demonstrate potentials of WVBF in the treatment of T2DM and possible mechanisms for its hepatoprotective activities.

关键词： Veratrilla baillonii Franch Type 2 diabetes mellitus Liver injury Skeletal muscle GLUT4

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Critical precipitation behavior of MnTe inclusions in resulfurized steels during solidification

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International Journal of Minerals,Metallurgy and Materials 2024年第8期31卷 1849-1857页

作者： Xiangyu xu Lu Zhang Zifei Wang Qianren Tian jianxun Fu xuemin Wang Center for Advanced Solidification Technology(CAST) School of Materials Science and EngineeringShanghai UniversityShanghai 200444China State Key Laboratory of Advanced Special Steel Shanghai UniversityShanghai 200444China Collaborative Innovation Center of Steel Technology University of Science and Technology BeijingBeijing 100083China Yangjiang Branch Guangdong Laboratory for Materials Science and Technology(Yangjiang)Advanced Alloys LaboratoryYangjiang 529500China

Te treatment is an effective method for modifying sulfide inclusions,and MnTe precipitation has an important effect on thermal brittleness and steel corrosion resistance.In most actual industrial applications of Te treatment,MnTe precipitation is unexpected.The critical precipitation behavior of MnTe inclusions was investigated through scanning electron microscopy,transmission electron microscopy,machine learning,and first-principles calculation.MnTe preferentially precipitated at the container mouth for sphere-like sulfides and at the interface between MnS grain boundaries and steel matrix for rod-like sulfides.The MnS/MnTe interface was semicoherent.A composition transition zone with a rock-salt structure exhibiting periodic changes existed to maintain the semicoherent interface.The critical precipitation behavior of MnTe inclusions in resulfurized steels involved three stages at varying temperatures.First,Mn(S,Te)precipitated during solidification.Second,MnTe with a rock-salt structure precipitated from Mn(S,Te).Third,MnTe with a hexagonal NiAs structure transformed from the rock-salt structure.The solubility of Te in MnS decreased with decreasing temperature.The critical precipitation behavior of MnTe inclusions in resulfurized steels was related to the MnS precipitation temperature.With the increase in MnS precipitation temperature,the critical Te/S weight ratio decreased.In consideration of the cost-effectiveness of Te addition for industrial production,the Te content in resulfurized steels should be controlled in accordance with MnS precipitation temperature and S content.

关键词： resulfurized steels modification of inclusion manganese telluride precipitation

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色散混合显隐式时域有限差分法的石墨烯仿真

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电波科学学报 2019年第2期34卷 239-243页

作者：徐健勋傅伟杰合肥工业大学合肥230009

应用色散混合显隐式时域有限差分(hybrid implicit-explicit finite-difference time-domain, HIE-FDTD)法分析了石墨烯的电磁特性.这种方法的时间步长大小不受石墨烯层的剖分网格大小的限制,数值算例表明,HIE-FDTD方法是一种精度较高... 详细信息

应用色散混合显隐式时域有限差分(hybrid implicit-explicit finite-difference time-domain, HIE-FDTD)法分析了石墨烯的电磁特性.这种方法的时间步长大小不受石墨烯层的剖分网格大小的限制,数值算例表明,HIE-FDTD方法是一种精度较高的有效算法,它的计算时间比FDTD方案大大减少.数值计算结果显示,设计的石墨烯吸收体通过改变石墨烯片的化学势,可以有效地调整吸收体的吸收峰.同时发现,在太赫兹频率下石墨烯吸收体的吸收率显示出一定的周期性并呈现栅形特性,这一特性可以对石墨烯器件的设计生产提供一些思路.

关键词：色散混合显隐式时域有限差分方法石墨烯电磁特性石墨烯吸收体

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OFDM-based visible light communication with rotated polarity modulation aided complex color shift keying

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Chinese Optics Letters 2019年第10期17卷 102-107页

作者：徐建勋江明陈裕发 Sun Yat-sen University (SYSU)

High-rate techniques,such as optical orthogonal frequency division multiplexing(OFDM)and color shift keying(CSK),have been proposed for visible light communication(VLC).To fully exploit their advantages,in this Letter,we design a modulation scheme called rotated polarity modulation(RPM)aided complex CSK(CCSK)for OFDM-based VLC systems and derive its theoretical bit error rate and an optimal scaling factor.Analytical and simulation results show that in comparison to the existing schemes,the new RPM-CCSK-OFDM system offers an improved link performance and data rate under a modest complexity.It can also be applied to VLC systems equipped with different types of LED devices,thus enabling flexible deployments.

关键词： communication keying visible

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Data fusion for target tracking in wireless sensor networks using quantized innovations and Kalman filtering

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Science China(Information Sciences) 2012年第3期55卷 530-544页

作者： xu Jian1,2 , LI jianxun1,2 & xu Sheng3 1Department of Automation, Science and Technology on Avionics Integration Laboratory, Shanghai Jiao Tong University, Shanghai 200240, China 2Department of Automation, System Control and Information Processing, Ministry of Education of China, Shanghai Jiao Tong University, Shanghai 200240, China 3School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China Department of Automation Science and Technology on Avionics Integration Laboratory Shanghai Jiao Tong University Shanghai China Department of Automation System Control and Information Processing Ministry of Education of China Shanghai Jiao Tong University Shanghai China School of Mechanical Engineering Shanghai Jiao Tong University Shanghai China

A novel networked data-fusion method is developed for the target tracking in wireless sensor networks (WSNs). Specifically, this paper investigates data fusion scheme under the communication constraint between the fusion center and each sensor. Such a message constraint is motivated by the bandwidth limitation of the communication links, fusion center, and by the limited power budget of local sensors. In the proposed scheme, each sensor collects one noise-corrupted sample, performs a quantizing operation, and transmits quantized message to the fusion center. Then the fusion center combines the received quantized messages to produce a final estimate. The novel data-fusion method is based on the quantized measurement innovations and decentralized Kalman filtering (DKF) with feedback. For the proposed algorithm, the performance analysis of the estimation precision is provided. Finally, Monte Carlo simulations show the effectiveness of the proposed scheme.

关键词： data fusion target tracking limited bandwidth quantized innovation Kalman filtering

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