检索结果-南通市图书馆

Friction reactions induced by selective hydrogenation of textured surface under lubricant conditions

Friction 2024年第1期12卷 174-184页

作者： naizhou du Xubing WEI Xiaowei LI Zan CHEN Shiqi LU Jiaqing DING Cunao FENG Kai CHEN Jianghao QIAO Dekun ZHANG Kwang-Ryeol LEE Tiancai ZHANG School of Materials Science and Physics China University of Mining and TechnologyXuzhou 221116China Key Laboratory of Marine Materials and Related Technologies Zhejiang Key Laboratory of Marine Materials and Protective TechnologiesNingbo Institute of Materials Technology&EngineeringChinese Academy of SciencesNingbo 315201China Computational Science Center Korea Institute of Science and TechnologySeoul 136-791Republic of Korea Technology Development Department Shipbuilding Technology Research InstituteShanghai 200032China

The passivation of hydrogen atoms and the conformation of textured surfaces under oil-lubricated conditions are effective strategies to obtain amorphous carbon(a-C)films with extremely low friction.It is critical to understanding the influence mechanism of selective surface hydrogenation on the tribological behaviors of textured a-C film under oil-lubricated conditions.In particular,the interactions of hydrogen atoms and lubricants are confusing,which is enslaved to the in situ characterization technique.The reactive molecular dynamics(RMD)simulations were conducted to analyze the friction response of textured a-C films with selective hydrogenation surfaces under oil-lubricated conditions.The results indicate that the existence of hydrogen atoms on specific bump sites significantly decreases the friction coefficient(μ)of textured a-C film,which is highly dependent on the surface hydrogen content.The repulsion between hydrogen atoms and lubricant molecules prompts the formation of a dense lubricant film on the surface of the mating material.Interestingly,with the enhancement of the surface hydrogen content,the passivation of the friction interface and the repulsion between hydrogen atoms and lubricants play dominant roles in reducing the friction coefficient instead of hydrodynamic lubrication.

关键词： textured amorphous carbon(a-C) selective hydrogenation oil lubrication friction mechanism reactive molecular dynamics(RMD)

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Insights into friction behavior of textured amorphous carbon and lubricant composite system: Dependence on the lubricant viscosity and textured shape

引用

Progress in Natural Science:Materials International 2023年第5期33卷 616-624页

作者： Jiaqing Ding naizhou du Xubing Wei Xiaowei Li Zan Chen Shiqi Lu Haolin Zhang Cunao Feng Kai Chen Jianghao Qiao Dekun Zhang Kwang-Ryeol Lee School of Materials Science and Physics China University of Mining and Technology Key Laboratory of Marine Materials and Related Technologies Zhejiang Key Laboratory of Marine Materials and Protective Technologies Ningbo Institute of Materials Technology and Engineering Chinese Academy of Sciences Computational Science Center Korea Institute of Science and Technology

Combining textured amorphous carbon(a-C) film with lubricant achieves ultra-low friction to improve the mechanical component’s service life. However, the coupling influence of lubricant viscosity and textured shape on friction behavior and interfacial transformation are still unclear. In this work, the evolution of friction performance with Poly-alpha-olefin viscosities and its dependence on textured shapes were investigated by reactive molecular dynamics simulation. Results reveal that as the textured shape is fixed, increasing the lubricant viscosity causes friction coefficient to decline first and then increase, due to the hydrodynamic lubrication and regional aggregation of lubricant. While under same lubricant condition, rectangular textured systems exhibit lower friction coefficient than circular textured ones, attributing to the formation of stable lubricant film without serious aggregation.

关键词： Amorphous carbon Lubricant Reactive molecular dynamics Surface texture

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

基于交叉注意力多源数据增强的情境感知查询建议方法

引用

北京大学学报（自然科学版） 2024年第1期60卷 34-42页

作者：张乃洲曹薇河南财经政法大学计算机与信息工程学院郑州450046

当前基于神经网络模型的查询建议研究往往单独采用查询日志会话中的查询序列作为训练数据,但由于查询本身缺乏句法关系,甚至缺失语义,导致神经网络模型不能充分挖掘和推理查询序列中各种词或概念之间语义关系。针对这一问题,提出一种基... 详细信息

当前基于神经网络模型的查询建议研究往往单独采用查询日志会话中的查询序列作为训练数据,但由于查询本身缺乏句法关系,甚至缺失语义,导致神经网络模型不能充分挖掘和推理查询序列中各种词或概念之间语义关系。针对这一问题,提出一种基于交叉注意力多源数据增强(MDACA)的Transformer模型框架,用于生成情境感知的查询建议。采用基于Transformer的编码器-解码器模型,利用交叉注意力机制,融合了查询层、文档语义层以及全局查询建议信息。实验结果表明,与目前方法相比,该方法能生成具有更高相关性的情境感知查询建议。

关键词：查询建议数据增强交叉注意力情境感知 Transformer模型

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Room-temperature third-order nonlinear Hall effect in Weyl semimetal TalrTe4

引用

National Science Review 2022年第12期9卷 177-184页

作者： Cong Wang Rui-Chun Xiao Huiying Liu Zhaowei Zhang Shen Lai Chao Zhu Hongbing Cai naizhou Wang Shengyao Chen Ya Deng Zheng Liu Shengyuan A.Yang Wei-Bo Gao College of Mathematics and Physics Beijing University of Chemical Technology Division of Physics and Applied Physics School of Physical and Mathematical Sciences Nanyang Technological University Institute of Physical Science and Information Technology Anhui University Research Laboratory for Quantum Materials Singapore University of Technology and Design School of Materials Science and Engineering Nanyang Technological University CAS Center for Excellence in Nanoscience National Center for Nanoscience and Technology The Photonics Institute and Centre for Disruptive Photonic Technologies Nanyang Technological University

The second-order nonlinear Hall effect observed in the time-revers al symmetric system has not only shown abundant physical content,but also exhibited potential application prospects.Recently,a third-order nonlinear Hall effect has been observed in MoTe2and WTe2.However,few-layer MoTe2and WTe2are usually unstable in air and the observed third-order nonlinear Hall effect can be measured only at low temperature,which hinders further investigation as well as potential application.Thus,exploring new air-stable material systems with a sizable third-order nonlinear Hall effect at room temperature is an urgent task.Here,in type-Ⅱ Weyl semimetal TaIrTe4,we observed a pronounced third-order nonlinear Hall effect,which can exist at room temperature and remain stable for months.The third-order nonlinear Hall effect is connected to the Berry-connection polarizability tensor instead of the Berry curvature.The possible me chanism of the observation of the third-order nonlinear Hall effe ct in TaIrTe4at room temperature has been discussed.Our findings will open an avenue towards exploring room-temperature nonlinear devices in new quantum materials.

关键词： topological material third-order nonlinear Hall effect room temperature Berry connection polarizability tensor

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Anti-windup-based Dynamic Controller Synthesis for Lipschitz Systems under Actuator Saturation

引用

IEEE/CAA Journal of Automatica Sinica 2015年第4期2卷 358-365页

作者： naizhou Wang Hailong Pei Yong Tang Key Laboratory of Autonomous Systems and Networked Control Ministry of EducationSouth China University of Technology Key Laboratory of Surface Functional Structure Manufacturing of Guangdong Higher Education Institutes School of Mechanical and Automotive EngineeringSouth China University of Technology

This paper presents a new method for simultaneous synthesis of dynamic controller and static anti-windup compensator for saturated Lipschitz systems. Thanks to the reformulated Lipschitz property, the Lipschitz systems can be transformed into LPV(linear parameter-varying) systems whose system matrices are affine in a parameter matrix. Based on the modified sector condition dealing with saturation nonlinearity, the design of a nonlinear anti-windup-based controller leads to the solvability of a set of bilinear matrix inequalities(BMI) on the vertices of a bounded convex set which can be solved by the so-called iterative linear matrix inequality(ILMI) algorithm. A numerical example is presented to illustrate the effectiveness of the proposed method.

关键词： Anti-windup Lipschitz system linear matrix inequality(LMI) region of attraction(ROA)

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Superconductivity in potassium and ammonia co-intercalated FeSe_(1-x)Te_x

引用

Science China(Physics,Mechanics & Astronomy) 2019年第4期62卷 84-90页

作者： BinBin Xiao naizhou Wang Chao Shang FanBao Meng JianWen Ding Bin Lei XiGang Luo Department of Physics and Institute for Nanophysics and Rare-earth Luminescence Xiangtan University College of Physics and Electronics Engineering Hengyang Normal University Hefei National Laboratory for Physical Science at Microscale and Department of Physics University of Science and Technology of China

The origin of the ～40 and ～30 K superconducting phases in the metal-intercalated FeSe superconductors is still unclear. We report the synthesis of K_(0.3)(NH_3)_y(FeSe_(1-x)Te_x)_2 and K_(0.6)(NH_3)_y(FeSe_(1-x)Te_x)_2 with x=0-0.6 by using the liquid ammonia method at room temperature. The superconducting transition temperature Tcof the former remains about 43 K for all the nominal Te content less than 0.3, while that of the latter is about 30 K and obviously decreases with Te doping. Superconductivity disappears for x ≥0.4 in both systems. Except for the different chemical pressure induced by substitution of Te for Se in both systems, we also observed distinct external pressure effect on superconductivity for both systems, with much more efficiency of suppressing Tcby external pressure in the former system. These dramatic differences of both chemical and external pressure effects on Tc between the ～30 and ～40 K superconducting phases revealed that the existence of the two superconducting phases can be ascribed to the moderate and negligible coupling between FeSe layers, respectively.

关键词： pnictides and chalcogenides properties of superconductors effects of pressure methods of materials synthesis and materials processing

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Magnetic field-induced electronic phase transition in the Dirac semimetal state of black phosphorus under pressure

引用

Science Bulletin 2018年第23期63卷 1539-1544页

作者： Zeliang Sun Ziji Xiang Zhongyi Wang Jinglei Zhang Long Ma naizhou Wang Chao Shang Fanbao Meng Liangjian Zou Yuanbo Zhang Xianhui Chen Hefei National Laboratory for Physical Sciences at Microscale and Department of Physics and CAS Key Laboratory of Strongly-Coupled Quantum Matter PhysicsUniversity of Science and Technology of ChinaHefei 230026China Key Laboratory of Materials Physics Institute of Solid State PhysicsChinese Academy of SciencesHefei 230031China Anhui Province Key Laboratory of Condensed Matter Physics at Extreme Conditions and High Magnetic Field LaboratoryChinese Academy of SciencesHefei 230031China State Key Laboratory of Surface Physics and Department of Physics Fudan UniversityShanghai 200433China Collaborative Innovation Center of Advanced Microstructures Nanjing UniversityNanjing 210093China

Different instabilities have been confirmed to exist in the three-dimensional(3D) electron gas when it is confined to the lowest Landau level in the extreme quantum limit. The recently discovered 3D topological semimetals offer a good platform to explore these phenomena due to the small sizes of their Fermi pockets, which means the quantum limit can be achieved at relatively low magnetic fields. In this work, we report the high-magnetic-field transport properties of the Dirac semimetal state in pressurized black phosphorus. Under applied hydrostatic pressure, the band structure of black phosphorus goes through an insulator-semimetal transition. In the high pressure topological semimetal phase, anomalous behaviors are observed on both magnetoresistance and Hall resistivity beyond the relatively low quantum limit field, which is demonstrated to indicate the emergence of an exotic electronic state hosting a density wave ordering. Our findings bring the first insight into the electronic interactions in black phosphorus under intense field.

关键词： Black phosphorus High magnetic field Quantum limit Electron phase transition

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

一种基于文本语义扩展的记忆网络查询建议模型

引用

山东大学学报（理学版） 2023年第12期58卷 10-21页

作者：张乃洲曹薇河南财经政法大学计算机与信息工程学院河南郑州450046

提出了一种新的基于文本语义扩展的记忆网络模型,用于生成环境感知的查询建议。采用基于注意力机制的分层编码器-解码器模型,利用外部记忆网络,生成查询与查询相关文档之间的神经注意力向量。模型融合了查询层、会话层和文档层语义信息... 详细信息

提出了一种新的基于文本语义扩展的记忆网络模型,用于生成环境感知的查询建议。采用基于注意力机制的分层编码器-解码器模型,利用外部记忆网络,生成查询与查询相关文档之间的神经注意力向量。模型融合了查询层、会话层和文档层语义信息,与目前的研究方法相比,能生成具有更高相关性的环境感知查询建议。使用真实的商业搜索引擎查询日志进行了实验,实验结果表明了该模型的有效性。

关键词：查询建议文本语义扩展环境感知记忆网络编码器-解码器模型

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Electric-field-controlled superconductor–ferromagnetic insulator transition

引用

Science Bulletin 2019年第10期64卷 653-658页

作者： Likuan Ma Bin Lei naizhou Wang Kaishuai Yang Dayong Liu Fanbao Meng Chao Shang Zeliang Sun Jianhua Cui Changsheng Zhu Tao Wu Zhe Sun Liangjian Zou Xianhui Chen Hefei National Laboratory for Physical Sciences at Microscale and Department of Physics and CAS Key Laboratory of Strongly-coupled Quantum Matter Physics University of Science and Technology of China Hefei 230026 China Key Laboratory of Materials Physics Institute of Solid State Physics Chinese Academy of Sciences Hefei 230031 China CAS Center for Excellence in Quantum Information and Quantum Physics Hefei 230026 China Collaborative Innovation Center of Advanced Microstructures Nanjing University Nanjing 210093 China National Synchrotron Radiation Laboratory University of Science and Technology of China Hefei 230026 China G4S Center for Excellence in Superconducting Electronics (CENSE) Shanghai 200050 China

Superconductivity beyond electron-phonon mechanism is always twisted with magnetism. Based on a new field-effect transistor with solid ion conductor as the gate dielectric(SIC-FET), we successfully achieve an electric-field-controlled phase transition between superconductor and ferromagnetic insulator in(Li,Fe)OHFeSe. A dome-shaped superconducting phase with optimal T_c of 43K is continuously tuned into a ferromagnetic insulating phase, which exhibits an electric-field-controlled quantum critical behavior. The origin of the ferromagnetism is ascribed to the order of the interstitial Fe ions expelled from the(Li,Fe)OH layers by gating-controlled Li injection. These surprising findings offer a unique platform to study the relationship between superconductivity and ferromagnetism in Fe-based superconductors. This work also demonstrates the superior performance of the SIC-FET in regulating physical properties of layered unconventional superconductors.

关键词： FeSe-based superconductors Ferromagnetic insulator Phase transition Solid ion conductor field-effect transistors (SIC-FET)

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Magnetic-field enhanced high-thermoelectric performance in topological Dirac semimetal Cd3As2 crystal

引用

Science Bulletin 2018年第7期63卷 411-418页

作者： Honghui Wang Xigang Luo Weiwei Chen naizhou Wang Bin Lei Fanbao Meng Chao Shang Likuan Ma Tao Wu Xi Dai Zhengfei Wang Xianhui Chen Hefei National Laboratory for Physical Science at Microscale and Department of Physics University of Science and Technology of China and Key Laboratory of Strongly-coupled Quantum Matter Physics. Chinese Academy of Sciences Hefei 230026 China Physics Department Hong Kong University of Science and Technology Hang Kong China High Magnetic Field Laboratory of the Chinese Academy of Sciences Hefei 230031 China Collaborative Innovation Center of Advanced Microstructures Nanjing University Nanjing 210093 China

Thermoelectric materials can be used to convert heat to electric power through the Seebeck effect. We study magneto-thermoelectric figure of merit(ZT) in three-dimensional Dirac semimetal Cd_3As_2 crystal.It is found that enhancement of power factor and reduction of thermal conductivity can be realized at the same time through magnetic field although magnetoresistivity is greatly increased. ZT can be highly enhanced from 0.17 to 1.1 by more than six times around 350 K under a perpendicular magnetic field of 7 T. The huge enhancement of ZT by magnetic field arises from the linear Dirac band with large Fermi velocity and the large electric thermal conductivity in Cd_3As_2. Our work paves a new way to greatly enhance the thermoelectric performance in the quantum topological materials.

关键词：垂直磁场半金属热电拓扑水晶性能 CdsA 热传导性

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：