Functional testing is key to fulfill quality control in laptop manufacturing and is of great economic ***,due to the unavailability of practical data,mathematical model and systematic perspective,it has barely been to...
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Functional testing is key to fulfill quality control in laptop manufacturing and is of great economic ***,due to the unavailability of practical data,mathematical model and systematic perspective,it has barely been touched from the academic community to *** the first time,this work provides technical understanding of the key principles of functional testing,mathematically models the general framework,elucidates existing testing strategy under the proposed framework and model,and finally proposes a specified optimization strategy which outperforms existing *** work lays the model foundation for the further optimization of functional testing,and can be regarded as a good example of how a systematic approach can solve practical industrial challenges.
Databases play a vital role in data management in many fields,such as finance,government,telecommunications,energy,electricity,transportation,*** the database management system has become a core foundational *** is an...
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Databases play a vital role in data management in many fields,such as finance,government,telecommunications,energy,electricity,transportation,*** the database management system has become a core foundational *** is an enterprise-grade open-source database,a product of deep integration of research and development from Huawei,Tsinghua University,and China Mobile in the past decade.
The prevailing view on long-range correlations is that they typically attenuate uniformly with distance and temperature, as most interactions either exhibit short-range dominance or decay following a power law. In con...
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The prevailing view on long-range correlations is that they typically attenuate uniformly with distance and temperature, as most interactions either exhibit short-range dominance or decay following a power law. In contrast to this belief, this Letter demonstrates that the intricate interplay between quasiperiodicity and the quasi-one-dimensional (1D) nature of subbands can result in strong long-range coupling without attenuation, a phenomenon referred to as an immortal interaction. Exemplifying a periodically stacked Fibonacci chain, we uncover an immortal interaction with greatly enhanced, persistent long-range coupling. Using negativity, it is shown that this interaction creates stable entanglement that endures over long distances and remains robust at finite temperatures. Additionally, unconventional logarithmic scaling entanglement is revealed, deviating from the traditional area law. These findings offer quasiperiodic quasi-1D systems as a prospective platform for sustaining stable entanglement across exceptionally long distances, even in the presence of finite-temperature effects.
Rectangular microchannel heat sinks(MCHS)are widely used to cool high-heat-flux electronic ***,previous studies focused mainly on MCHS with uniform channels(UCs).This study considers a microchannel heat sink with non-...
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Rectangular microchannel heat sinks(MCHS)are widely used to cool high-heat-flux electronic ***,previous studies focused mainly on MCHS with uniform channels(UCs).This study considers a microchannel heat sink with non-uniform channels(NUCs).A mathematical model is developed based on energy equations and the Darcy flow *** expressions for total thermal resistance and coolant pressure drop are derived using the thermoelectric *** and numerical simulations are performed to verify the mathematical *** non-uniformity increases,total coolant pressure drop decreases but at the cost of higher thermal *** overall performance of NUCs is better than that of UCs because of their lower ratio of pumping power to cooling *** transfer performance of NUCs changes little for more than 120 channels and depends mainly on channel arrangement.A multi-objective optimization is conducted to minimize the thermal resistance and pumping power of an *** optimal NUC saves 64%pumping power compared with a conventional UC for the total thermal resistance of 0.1℃/W,indicating that the use of non-uniform channels could be very helpful to reduce the flow resistance of MCHS.
Nonreciprocity of thermal metamaterials has significant application prospects in isolation protection,unidirectional transmission,and energy ***,due to the inherent isotropic diffusion law of heat flow,it is extremely...
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Nonreciprocity of thermal metamaterials has significant application prospects in isolation protection,unidirectional transmission,and energy ***,due to the inherent isotropic diffusion law of heat flow,it is extremely difficult to achieve nonreciprocity of heat *** review presents the recent developments in thermal nonreciprocity and explores the fundamental theories,which underpin the design of nonreciprocal thermal metamaterials,i.e.,the Onsager reciprocity ***,three methods for achieving nonreciprocal metamaterials in the thermal field are elucidated,namely,nonlinearity,spatiotemporal modulation,and angular momentum bias,and the applications of nonreciprocal thermal metamaterials are *** also discuss nonreciprocal thermal ***,the potential applications of nonreciprocity to other Laplacian physical fields are ***,the prospects for advancing nonreciprocal thermal metamaterials are highlighted,including developments in device design and manufacturing techniques and machine learning-assisted material design.
Most periodic systems are governed by short-range interactions as long-range interactions in these systems diminish uniformly. In this Letter, however, we demonstrate that this is not true for a more general class of ...
Most periodic systems are governed by short-range interactions as long-range interactions in these systems diminish uniformly. In this Letter, however, we demonstrate that this is not true for a more general class of systems, which possess long-range order without periodicity, known as quasiperiodic systems. Quasiperiodicity alters the well-known characteristics of the long-range couplings, resulting in anomalous enhancement for arbitrarily long distances, even beyond the mesoscopic scale. By exemplifying the indirect spin exchange interaction, we show that the long-range coupling in a quasiperiodic chain does not attenuate over distance but is instead governed by a distance metric, we have named the hyperspace geometric distance. This enables us to remotely control the spins over even mesoscopic distances. Our work provides new paradigms of strongly correlated physics applicable to a broader class of systems beyond the conventional ones.
There remains debate on whether Mn is beneficial or detrimental to hydrogen embrittlement in stainless *** this work,a series of stainless steels were designed to study the change of hydrogen embrit-tlement sensitivit...
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There remains debate on whether Mn is beneficial or detrimental to hydrogen embrittlement in stainless *** this work,a series of stainless steels were designed to study the change of hydrogen embrit-tlement sensitivity,crack propagation,and hydrogen trapping behaviors upon Mn *** results suggest that adding 4 wt.％Mn increased hydrogen embrittlement susceptibility,whereas adding 8 wt.％Mn decreased hydrogen embrittlement *** banded α'-martensite through austenitic grain is the main reason for the increased hydrogen embrittlement sensitivity when adding 4 wt.％Mn,by ad-sorbing hydrogen,promoting crack initiation,and accelerating crack propagation.
The influence of hard Al_(2)RE phases(Sc,Y,La,Ce,Pr,Nd,Sm,Eu,Gd,Tb,Dy,Ho,Er,Tm,Yb,and Lu)on the overall and local deformation as well as damage mechanism of Mg alloys has been studied by using a crystal plasticity mod...
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The influence of hard Al_(2)RE phases(Sc,Y,La,Ce,Pr,Nd,Sm,Eu,Gd,Tb,Dy,Ho,Er,Tm,Yb,and Lu)on the overall and local deformation as well as damage mechanism of Mg alloys has been studied by using a crystal plasticity model based on dislocation density with a brittle damage *** that lead to swift damage initiation and propagation throughout the matrix have been *** has been found that the hard Al_(2)RE with higher elastic modulus enhances the damage resistance of the Mg matrix,which was confirmed by fracture SEM/EDS characterizations and phase-field damage *** discovery provides valuable insights for designing Mg alloys with both high stiffness and enhanced damage resistance.
The hot deformation behaviors of sulfur-containing gear steel 20MnCr5 containing three different contents of Nb and B(0,0.021%Nb,and 0.024%Nb-0.0022%B)were *** compression and tenssion tests were carried out by Gleebl...
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The hot deformation behaviors of sulfur-containing gear steel 20MnCr5 containing three different contents of Nb and B(0,0.021%Nb,and 0.024%Nb-0.0022%B)were *** compression and tenssion tests were carried out by Gleeble3800 at the austenite region from 850 to 1150℃and the adverse effects of Nb and B were analyzed by the fracture,microstructure and precipitate *** compression tests showed that the proportions of instable area in hot processing maps of 0.021%Nb and Nb-B steels were higher and the deformability of Nb free steel was *** tensile deformation experiments showed that the reduction areas of Nb free,0.021%Nb and Nb-B steels were 92%-99%,84%-98%and 67%-97%,*** addition of Nb or Nb and B inhibited the dynamic recrystallization during hot deformation,and consequently,more deformed grains were then formed in 0.021%Nb and Nb-B steels thus to obtain the microstructure with worse uniformity and then deteriorate the *** addition,the interaction between inclusions and microalloyed elements was also *** particles of 0.021%Nb and Nb-B steels dynamically precipitated during deformation and precipitated together with MnS thus to worsen the deformability,resulting in the decrease of reduction area.
In recent years,explosion shock wave has been considered as a signature injury of the current military *** strong shock wave is lethal to the human body,weak shock wave can cause many more lasting *** investigate the ...
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In recent years,explosion shock wave has been considered as a signature injury of the current military *** strong shock wave is lethal to the human body,weak shock wave can cause many more lasting *** investigate the protection ability and characteristics of flexible materials and structures under weak shock wave loading,the blast wave produced by TNT explosive is loaded on the polyurethane foam with the density of 200.0 kg/m3(F-200)and 400.0 kg/m3(F-400),polyurea with the density of 1100.0 kg/m^(3)(P-1100)and structures composed of the two materials,which are intended for individual *** results indicate that the shock wave is attenuated to weak pressure disturbance after interacting with the flexible materials which are not *** shock wave protective capability of single-layer materials is dependent on their thickness,density and microscopic *** overpressure,maximum pressure rise rate and impulse of transmitted wave decrease exponentially with increase in sample *** the same thickness,F-400 provides better protective capability than F-200 while P-1100 shows the best protective capability among the three *** this study,as the materials are not destroyed,F-200 with a thickness more than10.0 mm,F-400 with a thickness more than 4.0 mm,and P-1100 with a thickness more than 1.0 mm can attenuate the overpressure amplitude more than 90.0%.Further,multi-layer flexible composites are *** layer layouts of designed structures and layer thickness of the single-layer materials can affect the protective *** the research range,the structure in which polyurea is placed on the impact side shows the optimal shock wave protective performance,and the thicknesses of polyurea and polyurethane foam are 1.0 mm and 4.0 mm *** overpressure attenuation rate reached maximum value of 93.3%and impulse attenuation capacity of this structure are better than those of s
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