检索结果-南通市图书馆

Lattice vibrations and Raman scattering in two- dimensional layered materials beyond graphene

Nano Research 2016年第12期9卷 3559-3597页

作者： xin Lu xin luo Jun Zhang Su Ying Quek Qihua Xiong Division of Physics and Applied Physics School of Physical and Mathematical Sciences Nanyang Technological University Singapore 637371 Singapore Department of Physics National University of Singapore 2 Science Drive 3 Singapore 117551 Singapore Centre for Advanced 2D Materials National University of Singapore 6 Science Drive 2 Singapore 117546 Singapore State Key Laboratory of Superlattices and Microstructures Institute of Semiconductors Chinese Academy of Sciences Beijing 100083 China NOVITAS Nanoelectronics Centre of Excellence School of Electrical and Electronic Engineering Nanyang Technological University Singapore 639798 Singapore

We review lattice vibrational modes in atomically thin two-dimensional （2D） layered materials, focusing on 2D materials beyond graphene, such as group VI transition metal dichalcogenides, topological insulator bismuth chalcogenides, and black phosphorus. Although the composition and structure of those materials are remarkably different, they share a common and important feature, i.e., their bulk crystals are stacked via van der Waals interactions between ＂layers＂, while each layer is comprised of one or more atomic planes. First, we review the background of some 2D materials （MX2, M = Mo, W; X = S, Se, Te. Bi2X3, X = Se, Te. Black phosphorus）, including crystalline structures and stacking order. We then review the studies on vibrational modes of layered materials and nanostructures probed by the powerful yet nondestructive Raman spectroscopy technique. Based on studies conducted before 2010, recent investigations using more advanced techniques have pushed the studies of phonon modes in 2D layered materials to the atomically thin regime, down to monolayers. We will classify the recently reported general features into the following categories： phonon confinement effects and electron-phonon coupling, anomalous shifts in high-frequency intralayer vibrational modes and surface effects, reduced dimensionality and lower symmetry, the linear chain model and the substrate effect, stacking orders and interlayer shear modes, polarization dependence, and the resonance effect. Within the seven categories, both intralayer and interlayer vibrational modes will be discussed. The comparison between different materials will be provided as well.

关键词： phonon lattice vibration Raman spectroscopy two-dimensional transition metaldichalcogenide black phosphorus

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

Low order nonconforming mixed finite element method for nonstationary incompressible Navier-Stokes equations

引用

Applied Mathematics and Mechanics(English Edition) 2016年第8期37卷 1095-1112页

作者： Chao XU Dongyang shi xin LIAO Faculty of Mathematics and Physics Education Luoyang Institute of Science and Technology School of Mathematics and Statistics Zhengzhou University

This paper studies a low order mixed finite element method （FEM） for nonstationary incompressible Navier-Stokes equations. The velocity and pressure are approximated by the nonconforming constrained Q1^4ot element and the piecewise constant, respectively. The superconvergent error estimates of the velocity in the broken H^1-norm and the pressure in the L^2-norm are obtained respectively when the exact solutions are reasonably smooth. A numerical experiment is carried out to confirm the theoretical results.

关键词： nonstationary incompressible Navier-Stokes equation constrained Q1^rot nonconforming finite element (FE) superconvergent error estimate

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

Metal-organic frameworks with dinuclear metal centers for synergistically boosting CO2 photoreduction

引用

Science China Chemistry 2025年第1期 201-208页

作者： Hui-Feng Wang Wen-Jie shi Yu-xin Yang Bao-Xia Dong Tong-Bu Lu Di-Chang Zhong School of Chemistry and Chemical Engineering Yangzhou University Institute for New Energy Materials and Low Carbon Technologies School of Materials Science and Engineering Tianjin University of Technology

Dinuclear metal synergistic catalysis （DMSC） has been proved powerful in boosting CO2reduction,while this has not been achieved in heterogeneous catalysts with long-range order *** this study,we,by introduction of metal catalytic centers into an indium-based metal-organic framework （MOF）,obtained a series of isostructural In-MOFs,including three MOFs with mononuclear metal catalytic center （M-In）,three MOFs with dinuclear homometallic catalytic centers （MM-In）,and three MOFs with dinuclear heterometallic catalytic centers (MM’-In,M/M’=Co（II）,Ni（II）,Zn（II）).It was found that all these MOFs can serve as catalysts for photochemical CO2reduction to *** with M-In,the catalytic activities of MM-In were obviously enhanced,and that of MM’-In was further significantly *** example,the CO yield of Co Zn-In reaches a record value of 12,700μmol g-1h-1,which is 4.0,8.1,9.4,and 18.6-fold higher than that of Co Co-In,Zn Zn-In,Co-In,and Zn-In,***,the catalytic activities of Co Ni-In and Ni Zn-In also show different fold increase than those of corresponding dinuclear homometallic and mononuclear metallic *** results of control experiments and theoretical calculation reveal that the higher catalytic activities of MM-In over M-In can be ascribed to the DMSC effect,and the higher catalytic activity of MM’-In over MM-In can be ascribed to the strengthened DMSC *** work reveals the relationship between DMSC effect and bimetal centers in CO2reduction,which provides new insights into the DMSC and paves a new way to design highly active catalysts for photochemical CO2reduction.

关键词：

来源：

同方期刊数据库

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

羟基肉桂酸类化合物及其衍生物在阿尔茨海默病治疗中的研究进展

引用

海峡药学 2022年第8期34卷 78-82页

作者：徐李亮施罗欣洁李若赛张臻昊郭娜劳可静陕西省脑疾病防治重点实验室西安医学院基础与转化医学研究所陕西西安710021

阿尔茨海默病(Alzheimer′s disease,AD)是一种常见的神经退行性疾病,已经成为不容回避的社会公共卫生问题。羟基肉桂酸类化合物是广泛分布于多种植物中的一类酚酸类化合物,近年来,该类化合物在AD治疗中的作用日益成为研究热点。本文对... 详细信息

阿尔茨海默病(Alzheimer′s disease,AD)是一种常见的神经退行性疾病,已经成为不容回避的社会公共卫生问题。羟基肉桂酸类化合物是广泛分布于多种植物中的一类酚酸类化合物,近年来,该类化合物在AD治疗中的作用日益成为研究热点。本文对羟基肉桂酸类化合物在抗AD的作用机制及其结构改造的研究进展进行综述,以期为抗AD药物研发提供新策略。

关键词：羟基肉桂酸阿尔茨海默病作用机制衍生物

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

Effect of Deep Sea Pressures on the Corrosion Behavior of X65 Steel in the Artificial Seawater

引用

Acta Metallurgica Sinica(English Letters) 2019年第8期32卷 972-980页

作者： Qiu-shi Li Shun-Zhong luo Xu-Teng xing Jing Yuan xin Liu Ji-Hui Wang Wen-Bin Hu Tianjin Key Laboratory of Composite and Functional Materials School of Materials Science and EngineeringTianjin UniversityTianjin 300072China College of Physics Electronic Information Engineering Qinghai University for NationalitiesXining 810007China

The corrosion behaviors of X65 steel in the artificial seawater at different hydrostatic pressures are investigated by potentiodynamic polarization measurements, electrochemical impedance spectroscopy measurements and weight loss *** corroded morphologies and the corrosion products are also investigated by scanning electron microscopy, X-ray diffraction analysis and Raman *** results show that the corrosion current increases as the hydrostatic pressure *** charge transfer resistance decreases as the hydrostatic pressure *** corrosion products are mainly composed of γ-FeOOH and Fe3O4 at the atmospheric pressure, while the main components are γ-FeOOH, Fe3O4, and γ-Fe2O3 at the high *** hydrostatic pressure accelerates the corrosion of X65 steel due to its effect on the chemical and physical properties of corrosion products, including the promoted reduction of γ-FeOOH and the wider and deeper cracks on the corrosion products layer.

关键词： X65 steel Deep sea pressures Electrochemical measurements Corrosion

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

The Method for Measuring Circuit Breaker Overtravel Based on Operating Process

引用

Instrumentation 2022年第3期9卷 37-42页

作者： HE Li xin Xiaonan shi Fengjie GUO Qiang luo Danyu State Grid Institute of Technology Zhengzhou Branch ZHENGZHOU ELECTTRIC POWER COLLEGEHenan Zheng Zhou450000 Zhengzhou University 450001 Yutong Bus Co. Ltd.Henan Zheng Zhou450000

At present,the over-travel measurement of high-voltage circuit breakers is mostly carried out after the circuit breaker is completely *** disadvantage of the measurement is that it can only be measured when the circuit breaker is dismantled and *** are diagnosed in a timely and effective manner,and capacity causes hidden *** article provides a method for direct measurement of hydraulic circuit breakers without any adjustment or *** method can be carried out in various situations such as minor repairs,major repairs,and temporary repairs,which not only saves time,but also improves accuracy of the *** comparative test results show that this method can be simple,convenient and effective to measure the overtravel of the high-voltage circuit breaker.

关键词： Circuit Breaker Stroke Over Stroke Hydraulic Mechanism Measurement

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

Comparative Experimental and Numerical Study of Wave Loads on A Monopile Structure Using Different Turbulence Models

引用

China Ocean Engineering 2021年第4期35卷 554-565页

作者： ZENG xin-meng shi Wei Constantine MICHAILIDES WANG Kai LI xin DeepWater Engineering Research Centre Dalian University of TechnologyDalian 116024China State Key Laboratory of Coastal and Offshore Engineering Dalian University of TechnologyDalian 116024China Civil Engineering and Geomatics Cyprus University of TechnologyLimassol 2026Cyprus School of Marine Engineering and Technology Sun Yat-Sen UniversityZhuhai 51900China

This study numerically and experimentally investigates the effects of wave loads on a monopile-type offshore wind turbine placed on a 1:25 slope at different water depths as well as the effect of choosing different turbulence models on the efficiency of the numerical *** numerical model adopts a two-phase flow by solving Unsteady Reynolds-Averaged Navier−Stokes(URANS)equations using the Volume Of Fluid(VOF)method and three differentk-􀀀ωturbulence *** environmental conditions from the East China Sea are *** wave run-up and the wave loads applied on the monopile are investigated and compared with relevant experimental data as well as with mathematical predictions based on relevant *** numerical model is well validated against the experimental data at model *** use of different turbulence models results in different predictions on the wave height but less differences on the wave *** baseline k-􀀀ωturbulence model and Shear-Stress Transport(SST)k-􀀀ωturbulence model exhibit better performance on the prediction of hydrodynamic load,at a model-scale water depth of 0.42 m,while the laminar model provides better results for large water *** SST turbulence model performs better in predicting wave run-up for water depth 0.42 m,while the laminar model and standard k-􀀀ωmodel perform better at water depth 0.52 m and 0.62 m,respectively.

关键词： hydrodynamic loads turbulence models Morison equation wave run-up numerical wave tank monopile structure

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

Microstructural evolution and hardness of as-cast Be-Al-Sc-Zr alloy processed by laser surface remelting

引用

Chinese Journal of Aeronautics 2021年第8期34卷 131-142页

作者： Qingdong XU Yu luo Xiangdong LIU Lei YANG shixiong HE xin WANG Wenyuan WANG Tao shi Ruiwen LI Pengcheng ZHANG Institute of Materials China Academy of Engineering PhysicsMianyang 621908China

As-cast beryllium-aluminum(Be-Al)alloy exhibits a coarse microstructure with pore defects due to a large solidification interval,greatly limiting its mechanical *** this research,the relationship between laser surface remelting process and microstructure and hardness of as-cast Be-Al-Sc-Zr alloy was *** experimental results demonstrated that a pore-free refined microstructure of remelted layer was obtained by controlling the parameter of effective laser energy *** microstructure of as-cast Be-Al-Sc-Zr alloy consisted of equiaxed grains with Al phase forming a continuous frame wrapping Be phase,which was significantly refined in the remelted zone(from 25μm to 2μm).The Vickers hardness in the remelted zone(approximately 210 HV)was approximately 3 times that of as-cast Be-Al-Sc-Zr *** of the Vickers hardness and the Be phase size showed a good agreement with a Hall-Petch *** addition,transmission electron microscopy(TEM),auger electron spectroscopy(AES)and X-ray diffraction(XRD)analysis evidenced that Sc and Zr elements formed a single blocky phase Be13(Scx,Zr1-x),which was also greatly refined from 8μm to 1.5μm in the remelted *** results obtained in this study indicate that the laser surface remelting allowed refining the microstructure and further strengthening the Vickers hardness of Be-Al-Sc-Zr alloy.

关键词： Be-Al alloy Laser energy input Laser surface remelting Hardness Microstructure

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

Efficient benzaldehyde photosynthesis coupling photocatalytic hydrogen evolution

引用

Journal of Energy Chemistry 2022年第3期31卷 52-60,I0003页

作者： Juanjuan luo Min Wang Lisong Chen Jianlin shi Shanghai Key Laboratory of Green Chemistry and Chemical Processes School of Chemistry and Molecular EngineeringEast China Normal UniversityShanghai 200062China State Key Laboratory of High Performance Ceramics and Superfine Microstructures Shanghai Institute of CeramicsChinese Academy of SciencesShanghai 200050China

Photosynthesis of organic compounds in coupling with promoted hydrogen evolution under mild conditions of light irradiation is considered as one of the most efficient and promising approach to obtain high purity hydrogen and value-added chemicals concurrently by utilizing green solar ***,we report the synthesis of Ni S nanoparticle-modified Cd S nanorod composites(Ni S/Cd S)as an efficient bifunctional catalyst for the highly selective photocatalytic synthesis of high-value-added product benzaldehyde(BAD)from aqueous solution of benzyl alcohol(BA)under oxygen-free conditions,in accompanying with the efficient hydrogen *** synergetic catalytic effect between Ni S and Cd S is proposed to play an important role in elevating the photo-redox *** composition-optimized 30%Ni S/Cd S catalyst affords an extraordinarily high H;generation rate of 207.8μmol h^(-1)and a simultaneous BAD generation rate of 163.8μmol h^(-1)under visible light irradiation,which are respectively 139 and 950 times higher than those of Cd S without Ni S *** our knowledge,these are the highest photocatalytic production rates of both H_(2)and aldehyde ever reported on the concurrent photocatalytic of aldehyde synthesis and hydrogen evolution in green aqueous *** work provides a highly efficient photosynthesis strategy for the concurrent productions of high-value-added fine chemicals and hydrogen.

关键词： Photosynthesis Aromatic aldehyde Hydrogen evolution Bifunctional catalyst

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

Microstructure and magnetocaloric properties of melt-extracted SmGdDyCoAl high-entropy amorphous microwires

引用

Rare Metals 2024年第3期43卷 1234-1242页

作者： shi-Jie Wei Hong-Xian Shen Lun-Yong Zhang Lin luo xin-xing Tang Jian-Fei Sun Xiao-Qing Li School of Materials Science and Engineering Harbin Institute of TechnologyHarbin150001China Applied Materials Physics Department of Materials Science and EngineeringKTH-Royal Institute of Technology10044StockholmSweden

This paper presents a systematic investigation of the microstructure and magnetocaloric properties of melt-extracted Sm_(20)Gd_(20)Dy_(20)Co_(20)Al_(20)high-entropy *** fabricated wires exhibited an amorphous structure,and the temperature interval of the undercooled liquid AT was 45 *** microwires underwent a second-order magnetic transition from a ferromagnetic to a paramagnetic state near the Curie temperature(T_(C)=52 K),The maximum magnetic entropy change(-ΔS_M^(max)),the relative cooling power and the refrigeration capacity reached 6.34 J·kg^(-1)·K^(-1).422.09 J·kg^(-1)and 332.94 J·kg^(-1),respectively,under a magnetic field change of 5 *** addition,the temperature-averaged entropy changes with two temperature lifts(3 and 10 K)were 6.32 and 6.27 J·kg^(-1)·K^(-1),*** good magnetocalorie performance highlights the significant potential for the Sm_(20)Gd_(20)Dy_(20)Co_(20)Al_(20)microwires to be used as magnetic refrigerant materials in low-temperature region *** work will serve as a valuable reference for future investigations on low-temperature high-entropy magnetocaloric materials.

关键词： Melt-extraction High-entropy amorphous microwires Magnetocaloric effect Magnetic refrigeration

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：