For simultaneous and quantitative thermophysical measurements of ultrasmall liquid volumes,we have recently developed and reported heated fluidic resonators(HFRs).In this paper,we improve the precision of HFRs in a va...
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For simultaneous and quantitative thermophysical measurements of ultrasmall liquid volumes,we have recently developed and reported heated fluidic resonators(HFRs).In this paper,we improve the precision of HFRs in a vacuum by significantly reducing the thermal loss around the sensing element.A vacuum chamber with optical,electrical,and microfluidic access is custom-built to decrease the convection loss by two orders of magnitude under 10-4 mbar *** a result,the measurement sensitivities for thermal conductivity and specific heat capacity are increased by 4.1 and 1.6 times,*** differentiating between deionized water(H2O)and heavy water(D2O)with similar thermophysical properties and~10%different mass densities,the signal-to-noise ratio(property differences over standard error)for H2O and D2O is increased by 9 and 5 times for thermal conductivity and specific heat capacity,respectively.
Many works on topological insulators have focused on periodic lattice systems,where short-and long-range order is *** we construct a two-dimensional amorphous photonic crystal with short-range order and a controllable...
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Many works on topological insulators have focused on periodic lattice systems,where short-and long-range order is *** we construct a two-dimensional amorphous photonic crystal with short-range order and a controllable level of long-range order and experimentally investigate the transport of topological edge states in this amorphous *** demonstrate that topology properties remain constant with unidirectional edge state propagation,immune to specific disorder *** partition phenomena of edge states are also observed at the intersection of four topological channels in microwave *** proposed amorphous configuration provides new opportunities to explore the relationship between short-range order and topology and may alleviate the fabrication difficulties of topological optical devices for practical applications.
Human behaviors can be understood from various forms of information such as sleep, emotions or health conditions. With the aid of advancedtechnology, sensors can capture the conditions of humans and provide valuable ...
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Nitride-reinforced(HfNbTaTiV)_(90)N_(10) high-entropy alloy aiming at high-temperature applications is de-signed in this *** FCC nitride phases are formed in situ in theBCC matrix by arc melt-ing technique,without com...
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Nitride-reinforced(HfNbTaTiV)_(90)N_(10) high-entropy alloy aiming at high-temperature applications is de-signed in this *** FCC nitride phases are formed in situ in theBCC matrix by arc melt-ing technique,without complex deformation or heat ***(HfNbTaTiV)_(90)N_(10) alloy exhibits a remarkable yield strength of 2716 MPa and ultimate compressive strength of 2833 MPa with a plas-tic strain of 10%at room ***,the alloy remains a high yield strength of 279 MPa at 1400℃.The nitride phases play an essential role in maintaining the excellent strength-ductility com-bination at room temperature and enhancing the high-temperature softening *** BCC and FCC phases possess the semi-coherent interface,which not only strengthens the BCC matrix but also promotes the compatible deformation of the duplex *** lattice coherency structure of the semi-coherent interface is conducive to the slip transfer of partial dislocations through the interface,which facilitates the accommodation of plastic *** cross-slip of the screw dislocations ef-fectively eliminates stress concentration and leads to good ductility of the dual-phase *** results demonstrate that the nitride phases achieve coordinate deformation with the matrix without deteriorat-ing the ductility of the(HfNbTaTiV)_(90)N_(10) alloy.
In this study,the temperature of the low-temperature reduction-diffusion(LTRD)process was successfully decreased to below 600℃by introducing LiClKCl eutectic molten salt with a low eutectic point(352℃)as a solvent f...
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In this study,the temperature of the low-temperature reduction-diffusion(LTRD)process was successfully decreased to below 600℃by introducing LiClKCl eutectic molten salt with a low eutectic point(352℃)as a solvent for Ca ***,the Sm-Fe binary compounds,which were synthesizable at previously-unexplored low temperatures by the LTRD process using LiCl-KCl eutectic molten salt,were investigated,including whether a new metastable or ThMn_(12)-type Sm-Fe binary phase was *** Sm-Fe phase transitions of the SmFe binary compounds at a low temperature were identified,and it was found that MgCu_(2)-type Sm-Fe,PuNi_(3)-type SmFe and TbCu_(7)-type Sm-Fe phases were synthesized and stable at 400,500 and 550℃*** no new metastable Sm-Fe and ThMn_(12)-type Sm-Fe compounds were discovered in this study,this work can demonstrate that it is possible to synthesize the Sm-Fe phase at very low temperatures by the LTRD process for the first time.
Adding Ti particles to magnesium alloy simultaneously enhances its strength and ***,how these particles influence on Mg alloy’s corrosion performance is seldom *** corrosion behavior of AZ31-Ti composites containing ...
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Adding Ti particles to magnesium alloy simultaneously enhances its strength and ***,how these particles influence on Mg alloy’s corrosion performance is seldom *** corrosion behavior of AZ31-Ti composites containing titanium nanoparticles(1.5 and 5 wt%)and micron particles(10 wt%)prepared by powder metallurgical in 3.5 wt%NaCl solution was *** results indicate that Ti particles serve as the primary location for the cathodic hydrogen reduction reaction,resulting in intense galvanic corrosion between the Ti and Mg *** nanoparticles distributed at the interface of the original AZ31 powder were in a discontinuous mesh structure,thus failing to act as a barrier against *** corrosion products with the existence of numerous cracks gradually peel off during the corrosion process and cannot protect the *** average corrosion rate P_(w) of AZ31,AZ31-1.5%Ti,AZ31-5%Ti,and AZ31-10%Ti after 7 days of immersion is 27.55,105.65,283.67,and 99.35 mm/y,***,AZ31-Ti composites can be considered as potential candidates for degradable fracturing ***,it is recommended to improve their corrosion resistance through surface treatment.
MgH_(2)is a promising solid-state hydrogen storage ***,its high thermodynamics and sluggish kinetics hinder its practical *** strategy is effective in improving its kinetic ***,the highly efficient catalysts or additi...
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MgH_(2)is a promising solid-state hydrogen storage ***,its high thermodynamics and sluggish kinetics hinder its practical *** strategy is effective in improving its kinetic ***,the highly efficient catalysts or additives are normally of low-yield in fabrication with high *** this work,a novel structural LaVO_(4)fabricated by a low-cost method of spraying dry followed by a calcination is used as a catalytic additive for the hydrogen storage of MgH_(2).With an optimized addition of LaVO_(4),the overall hydrogen storage performances of MgH_(2)are significantly *** onset dehydrogenation temperature of only 183℃is obtained after an initial activation of dehydrogenation and *** system can desorb 5.7 wt%H_(2)at 250℃within 10 min and maintains a dehydrogenation capacity of 5.0 wt%H_(2)after 50 *** is found that LaVO_(4)is transferred to lanthanum hydride and metallic vanadium in the initial dehydrogenation process,the former acts as a highly effective catalyst for the hydrogen storage of MgH_(2)and the latter undergoes reversible hydrogenation and dehydrogenation in the subsequent *** structural design of the catalyst and its scalable fabrication are highly valuable in realizing the practical application of catalytic strategy for the hydrogen storage of MgH_(2).
The Cu-based shape memory alloy(SMA)with highly oriented columnar crystals is an ideal candidate for the commercial application,especially the ones obtained through rapid cooling via additive manufacturing *** this wo...
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The Cu-based shape memory alloy(SMA)with highly oriented columnar crystals is an ideal candidate for the commercial application,especially the ones obtained through rapid cooling via additive manufacturing *** this work,Cu_(71)Al_(18)Mn_(11)(at%)shape memory alloy with strong<001>texture columnar grains was successfully prepared by selective laser melting(SLM).An L27(313)orthogonal array was designed to systematically investigate the effects of laser power,scanning speed,scanning spacing,layer thickness and their interactions on the forming quality of Cu_(71)Al_(18)Mn_(11)***_(71)Al_(18)Mn_(11)alloys with density of 7.3204 g·cm^(-3)and relative density of 99.18%were successfully prepared when the laser power,scanning speed,scanning distance and layer thickness were 240 W,1000 mm·s^(-1),0.11 mm and 25μm,the transformation onset temperature(Ms),martensite phase transformation termination temperature(Mf),austenite phase transformation onset temperature(AS)and austenite phase transformation termination temperature(Af)are-21.84,-26.04,-15.75 and-12.36℃,*** compression strength and fracture strain along the building direction(BD)were significantly superior to the scanning direction(SD),while the superelasticity of compression along the SD reached 2.50%,which was better than that of2.32%along *** mechanical property and superelasticity anisotropy due to the formation of columnar grains and texture were *** study shows that SLM is a proposed method for the preparation of Cu-Al-Mn SMAs with high superelasticity,which provides a new strategy for enhancing the shape memory alloy superelasticity.
The formation of tribolayers may play significant influences on fretting *** elevated temperature,the adhesion among wear debris and the increased diffusion rate facilitate the formation of ***,the intensification of ...
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The formation of tribolayers may play significant influences on fretting *** elevated temperature,the adhesion among wear debris and the increased diffusion rate facilitate the formation of ***,the intensification of oxidation at elevated temperature and the low diffusion rate in oxides may play an adverse *** present study aims to investigate the role of temperature in tribolayers in fretting wear using aγ-TiAl *** electron microscope,energy dispersive spectrometer,Raman spectrometer,transmission electron microscope and nanoindentation were utilized to investigate the wear debris,tribolayers,and wear *** fretting tests showed that,compared with that at room temperature(RT)and 350℃,significant reduction in wear rate and decrease in the fluctuation of friction coefficient occurred at 550 and 750℃.It was further revealed that when temperature raised from room temperature(RT)to 750℃,the oxidation of the wear debris increased slightly and the diffusion coefficients increased prominently,which facilities the formation of well tribo-sintered *** well tribo-sintered tribolayers presented homogenous structure,nanocrystalline grains with excellent mechanical properties,and resulted in the improvement in the fretting wear resistance of theγ-TiAl alloy at 550 and 750℃.
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