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Solvothermal-assisted liquid-phase exfoliation of large size and high quality black phosphorus

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Journal of Materiomics 2018年第2期4卷 129-134页

作者： Zhe Yan Xuexia He Liaona She Jie Sun Ruibing Jiang Hua Xu Feng Shi Zhibin Lei Zong-Huai Liu Key laboratory of Applied surface and Colloid Chemistry(Shaanxi Normal University) Ministry of EducationXi'an 710062China School of Materials Science and Engineering Shaanxi Normal UniversityXi'an 710062China Shaanxi Engineering lab for Advanced Energy Technology School of Materials Science and EngineeringShaanxi Normal UniversityXi'an 710119China

Black phosphorus(BP),especially for BP nanosheets,with unique layered structure among two dimensional(2D)materials has attracted much attention due to its outstanding physical properties,such as ultra-high mobility,in-plane anisotropic ***,the small horizontal-size of reported BP limits its applications in the integrated circuit or some functional *** this work,a solvothermalassisted liquid-phase exfoliation technique is firstly employed for preparing large size and high-quality BP *** the high-polar acetonitrile solvent,solvothermal treatment weakens the Van der Waals forces of block *** with the subsequently ultrasonic processing,effective exfoliation of large size and high-quality BP nanosheets are *** TEM,AFM and Raman results indicate that the prepared BP nanosheets are high quality with an average thickness of about 2 nm,and the horizontalsize is up to 10μ*** facile and effective method for exfoliated BP nanosheets provides a promising strategy for the exfoliation of other 2D materials.

关键词： Two dimensional materials black phosphorus liquid exfoliation Solvothermal method

Mechanism of Grain Refinement in Ferritic Stainless Steel Welds： Between Dendrite Fragmentation, Grain Detachment and Heterogeneous Nucleation

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材料科学与工程（中英文A版） 2011年第3X期1卷 321-327页

作者： Amuda Muhammed Olawale Hakeem Mridha Shahjahan Advanced Materials and surface Engineering research Unit Department of Manufacturing and Materials Engineering International Islamic University Malaysia Kuala Lumpur Malaysia

The morphology of the grain structure in fusion welds is generally columnar and elongated. This structure is highly anisotropic and makes weld metal susceptible to centerline hot cracking and poor notch impact toughness particularly in welds that are prone to brittle fracture such as the ferritic stainless steel welds. An equiaxed grain structure is preferred in weld metal. Considerable studies have been undertaken to produce equiaxed grains in welds using different welding techniques. These studies established that grain refinement in welds has a linear relationship to the density of equiaxed grain in the columnar-equiaxed transition morphology at both the top surface and cross section of the weld. The increased density of equiaxed grains is due to the control of local solidification parameters both at the advancing solid/liquid interface and at the centre of the weld pool. Several mechanisms ranging from heterogeneous nucleation to dendrite fragmentation and grain detachment have been put forward to explain the phenomenon of grain refinement in fusion welds. These mechanisms are quite contrasting. In the present effort, a cross evaluation of these mechanisms is undertaken to identify the dominant mechanism. The evaluation suggested that other than in certain cases of compositional/constitutional undercooling, dendrite fragmentation and grain detachment appear to be the controlling mechanisms except when specific steps are taken to introduce nuclei to promote heterogeneous nucleation.

关键词：不锈钢焊接形核机制晶粒细化异质形核钢焊缝铁素体条块分割粮食

Sand mining impact on Poyang Lake: a case study based on high-resolution bathymetry and sub-bottom data

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Journal of Oceanology and Limnology 2022年第4期40卷 1404-1416页

作者： Shuwei ZHENG Heqin CHENG Ming TANG Wei XU Enfeng LIU Shu GAO Jim BEST Yuehua JIANG Quanping ZHOU College of Geography and Environment Shandong Normal UniversityJinan 250358China State Key lab of Estuarine&Coastal research East China Normal UniversityShanghai 200062China Departments of Geology Geography and GISMechanical Science and Engineering and Ven Te Chow Hydrosystems LaboratoryUniversity of Illinois at Urbana-ChampaignUrbana IL 61801USA Nanjing Geological Survey Center China Geological SurveyNanjing 210016China

Poyang Lake in the Changjiang(Yangtze)River catchment has undergone frequent spring drought since 2003,and some researchers attributed this phenomenon to sand mining and the lakebed deformation in the outlet channel linking the lake with Changjiang River main ***,there is still a lack of high-resolution subaqueous geomorphological evidence of how sand mining led to lakebed deformation in the outlet *** examined the bed morphology and sub-bottom sedimentary structure of the outlet channel,using a multibeam echo sounder and sub-bottom profi ler in Poyang *** found that:(1)the subaqueous micro-topography types of the outlet channel are characterized by sand mining disturbance,natural erosional topography,and fl at bed and dunes,accounting for 44.9%,21.4%,28.6%,and 5.1%of the channel area,respectively;and(2)sand mining activity aff ects the local bed topography extensively and signifi *** depth of sandpits caused by sand mining varied from 1.4 m to 12 m deeper than the surrounding bed surface,with 4.41 m of depth increase on ***,the large-scale high-intensity sand mining activities and their signifi cant geomorphic eff ects demand for an improved assessment for future management and longer-term *** of the large-scale and ongoing high-intensity sand mining activities in the Poyang Lake outlet channel,these eff ects should raise caution in the future and contribute to monitoring eff orts that are essential to implement sustainable management *** present study and techniques implemented can serve as a scientifi c reference for dam construction and sand mining within the Poyang Lake basin.

关键词： lakebed deformation sand mining multibeam echo sounder Poyang Lake

A versatile interferometric technique for probing the thermophysical properties of complex fluids

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Light(Science & Applications) 2022年第5期11卷 979-990页

作者： Gopal Verma Gyanendra Yadav Chaudry Sajed Saraj Longnan Li Nenad Miljkovic Jean Pierre Delville Wei Li GPL Photonics lab State Key Laboratory of Applied OpticsChangchun Institute of OpticsFine Mechanics and PhysicsChinese Academy of Sciences130033 ChangchunChina School of Physical Sciences University of LiverpoolLiverpool L693BXUK Materials research laboratory University of IllinoisUrbanaILUSA Department of Mechanical Science and Engineering University of IllinoisUrbanaILUSA Department of Electrical and Computer Engineering University of IllinoisUrbanaILUSA International Institute for Carbon Neutral Energy research(WPI-I2CNER) Kyushu University744 MotookaNishi-kuFukuoka 819-0395Japan University of Bordeaux CNRSLOMAUMR 5798F-33405 TalenceFrance

Laser-induced thermocapillary deformation of liquid surfaces has emerged as a promising tool to precisely characterize the thermophysical properties of pure ***,challenges arise for nanofluid(NF)and soft biofluid systems where the direct interaction of the laser generates an intriguing interplay between heating,momentum,and scattering forces which can even damage soft ***,we report a versatile,pump-probe-based,rapid,and non-contact interferometric technique that resolves interface dynamics of complex fluids with the precision of~1 nm in thick-film and 150 pm in thin-film regimes below the thermal limit without the use of lock-in or modulated *** characterize the thermophysical properties of complex NF in three exclusively different types of ***,when the NF is heated from the bottom through an opaque substrate,we demonstrate that our methodology permits the measurement of thermophysical properties(viscosity,surface tension,and diffusivity)of complex NF and ***,in a top illumination configuration,we show a precise characterization of NF by quantitively isolating the competing forces,taking advantage of the different time scales of these ***,we show the measurement of NF confined in a metal cavity,in which the transient thermoelastic deformation of the metal surface provides the properties of the NF as well as thermo-mechanical properties of the *** results reveal how the dissipative nature of the heatwave allows us to investigate thick-film dynamics in the thin-film regime,thereby suggesting a general approach for precision measurements of complex NFs,biofluids,and optofluidic devices.

关键词： deformation thermophysical film

单层Ti_(3)C_(2)T_(x)的合成和电化学行为及其电容脱盐应用

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Journal of Central South University 2022年第2期29卷 359-372页

作者：闵小波刘繁松王云燕严艺琪王海鹰 School of Metallurgy and Environment Central South UniversityChangsha 410083China Chinese National Engineering research Center for Control&Treatment of Heavy Metal Pollution Changsha 410083China Water Pollution Control Technology Key lab of Hunan Province Changsha 410083China

MXene材料因其优异的电化学性能在环境处理领域受到广泛关注。其中Ti_(3)C_(2)T_(x)(T_(x)代表材料表面官能团如—O、—OH和—F)作为一种典型的MXene材料,其单层结构的化学物理特性较多层结构更优。因此,本文通过HF刻蚀MAX方法获得多层T... 详细信息

MXene材料因其优异的电化学性能在环境处理领域受到广泛关注。其中Ti_(3)C_(2)T_(x)(T_(x)代表材料表面官能团如—O、—OH和—F)作为一种典型的MXene材料,其单层结构的化学物理特性较多层结构更优。因此,本文通过HF刻蚀MAX方法获得多层Ti_(3)C_(2)T_(x),再通过无水乙醇插层-剥离处理制备了单层Ti_(3)C_(2)T_(x)材料,并组装成单层Ti_(3)C_(2)T_(x)电极进行电容脱盐应用。单层Ti_(3)C_(2)T_(x)材料厚度为0.8 nm,比表面积为235.6 m^(2)/g。结果表明单层Ti_(3)C_(2)T_(x)电化学性能得到了明显的改善,质量比电容量由52.1 F/g提升至144.7 F/g。在1000 mg/L NaCl溶液中,电压为1.2 V的条件下,单层Ti_(3)C_(2)T_(x)对NaCl的吸附量为30.7 mg/g,该吸附过程可以采用Langmuir等温线和准二级动力学方程进行描述,推测电吸附机理可以表示为双电层上发生的单层吸附过程。此工作为MXene基材料处理废水提供思路。

关键词：单层Ti_(3)C_(2)T_(x) 电容脱盐氯化钠电吸附机制 MXene材料

Visualization Experiment and Numerical Analysis of Cavitation Flow Characteristics in Diesel Fuel Injector Control Valve with Different Structure Design

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Journal of Thermal Science 2021年第1期30卷 76-87页

作者： MA Haoyuan ZHANG Tong AN Qingsong TAO Yuhao XU Yue School of Mechanical Engineering Tianjin UniversityTianjin 300350China Key lab of Efficient Utilization of Low and Medium Grade Energy Tianjin 300350China Shanghai Marine Diesel Engine research Institute Shanghai 201108China

Increasing the injection pressure has been proven an effective method to enhance performance and reduce pollutant of diesel *** the increase of the injection pressure,the cavitation damage problem inside common rail fuel injector is more significant,which has direct influences on reliability of diesel *** the most studies so far have focused on cavitation occurred in injector nozzle and its atomization characteristics,few researchers studied the cavitation phenomenon in fuel injector control *** due to the complexity of flow field and difficulty of experiment,the cavitation in control valve could not be fully described by existing *** this paper,the two-dimensional visualization experiment and numerical simulation of control valve was implemented to acquire the image of cavitation intuitively and validate the simulation method and *** a new structure design of control valve named convergent model was presented for *** origin model and convergent model with different valve lifts were simulated in three *** results showed that the sheet cavitation occurred at the surface of seal cone and steel ball then turned to cloud cavitation in downstream *** intensity of cavitation increased with the increase of valve *** model could efficiently reduce the cavitation intensity near the seal *** research could provide references for engineering optimization design of control valve.

关键词： diesel engine fuel injector control valve cavitation

Friction behaviour between a laparoscopic grasper and the large intestine during minimally invasive surgery

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Biosurface and Biotribology 2022年第1期8卷 58-68页

作者： Yan Guo Chengmo Cai Wei Li Key laboratory for Advanced Technology of Materials of Ministry of Education Tribology Research InstituteSouthwest Jiaotong UniversityChengduChina

Slippage is a common phenomenon between laparoscopic graspers and tissues during minimally invasive surgery,which may lead to inefficient surgical operations,prolonged operation time,and increased patient *** stability factors related to the friction behaviour between laparoscopic graspers and the large intestine,including bio-surface liquids,pulling angle,and surface profile of graspers,were *** friction behav-iour at the large intestine-grasper interface was tested using a UMT-II tribometer under the conditions of clamping force of 1-4 N,sliding displacement of 15 mm,and sliding velocity of 2 mm/s to simulate the grasping and pulling operations of soft *** results showed that the bio-surface liquid(serum)of the large intestine significantly decreased the friction coefficient,thus reducing the grasping efficiency.A pulling angle of 15°could generate the peak frictional force and enhance the grasping *** frictional force increased with the ratio of the profile surface area of the *** results demonstrate that the grasping stability can be improved by changing either the bio-surface liquid condition or the pulling *** addition,a grasper with a larger profile surface area can also prevent slippage due to its significant influence on the pressure distribution and actual contact area for tissue retention.

关键词： biointerface biomaterials biomechanics biotribology wear mechanism

Tribological Mechanism of Graphene and Ionic liquid Mixed Fluid on Grinding Interface under Nanofluid Minimum Quantity Lubrication

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Chinese Journal of Mechanical Engineering 2023年第4期36卷 79-96页

作者： Dexiang Wang Yu Zhang Qiliang Zhao Jingliang Jiang Guoliang Liu Changhe Li School of Mechanical and Automotive Engineering Qingdao University of TechnologyQingdaoChina Key lab of Industrial Fluid Energy Conservation and Pollution Control(Qingdao University of Technology) Ministry of EducationQingdaoChina

Graphene has superhigh thermal conductivity up to 5000 W/(m·K),extremely thin thickness,superhigh mechanical strength and nano-lamellar structure with low interlayer shear strength,making it possess great potential in mini-mum quantity lubrication(MQL)***,ionic liquids(ILs)have higher thermal conductivity and better thermal stability than vegetable oils,which are frequently used as MQL grinding *** ILs have extremely low vapor pressure,thereby avoiding film boiling in *** excellent properties make ILs also have immense potential in MQL ***,the grinding performance of graphene and ionic liquid mixed fluid under nano-fluid minimum quantity lubrication(NMQL),and its tribological mechanism on abrasive grain/workpiece grinding interface,are still *** research firstly evaluates the grinding performance of graphene and ionic liquid mixed nanofluids(graphene/IL nanofluids)under NMQL *** evaluation shows that graphene/IL nanofluids can further strengthen both the cooling and lubricating performances compared with MQL grinding using ILs *** specific grinding energy and grinding force ratio can be reduced by over 40%at grinding depth of 10μ***-piece machined surface roughness can be decreased by over 10%,and grinding temperature can be lowered over 50℃at grinding depth of 30μ*** at the unclear tribological mechanism of graphene/IL nanofluids,molecular dynamics simulations for abrasive grain/workpiece grinding interface are performed to explore the formation mechanism of physical adsorption *** simulations show that the grinding interface is in a boundary lubrication *** molecules absorb in groove-like fractures on grain wear flat face to form boundary lubrication film,and graphene nanosheets can enter into the grinding interface to further decrease the contact area between abrasive grain and *** with MQL grinding,the average tangential grinding force of graphene/IL nanof

关键词： Grinding Nanofluid minimum quantity lubrication Graphene Tribological mechanism

Water film coated composite liquid metal marble and its fluidic impact dynamics phenomenon

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Frontiers in Energy 2016年第1期10卷 29-36页

作者： Yujie DING Jing LIU Key lab of Cryogenics and Beijing Key lab of CryoBiomedicalEngineering Technical Institute of Physics and Chemistry ChineseAcademy of Sciences Beijing 100190 China Key lab of Cryogenics and Beijing Key lab of CryoBiomedicalEngineering Technical Institute of Physics and Chemistry ChineseAcademy of Sciences Beijing 100190 Department of Biomedical Engineering School of Medicine Tsinghua University Beijing 100084China

A composite liquid metal marble made of metal droplet coated with water film was proposed and its impact dynamics phenomenon was disclosed. After encapsulating the liquid metal into water droplets, the fabricated liquid marble successfully avoided being oxygenized by the metal fluid and thus significantly improved its many physical capabilities such as surface tension modification and shape control. The striking behaviors of the composite liquid metal marbles on a substrate at room temperature were experimentally inves- tigated in a high speed imaging way. It was disclosed that such marbles could disintegrate, merge, and even rebound when impacting the substrate, unlike the existing dynamic fluidic behaviors of liquid marble or metal droplet. The mechanisms lying behind these features were preliminarily interpreted. This fundamental finding raised profound multiphase fluid mechanics for understanding the complex liquid composite which was also critical for a variety of practical applications such as liquid metal jet cooling, inkjet printed electronics, 3D printing or metal particle fabrication etc.

关键词： liquid metal marble metallic droplet composite fluid impact dynamics multiphase fluid mechanics