Photoacoustic imaging,an acoustic imaging modality with potentially optical resolution in an optical turbid medium,has attracted great ***,the convergence of wavefront optimization and raster scanning in computational...
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Photoacoustic imaging,an acoustic imaging modality with potentially optical resolution in an optical turbid medium,has attracted great ***,the convergence of wavefront optimization and raster scanning in computational photoacoustic imaging leads to the challenge of fast mapping,especially for a spatial resolution approaching the acoustic deep-subwavelength *** a sparse sampling paradigm,compressive sensing has been applied in numerous fields to accelerate data acquisition without significant quality *** this work,we propose a dual-compressed approach for photoacoustic surface tomography that enables high-efficiency imaging with 3D spatial resolution unlimited by the acoustics in a turbid *** dual-compressed photoacoustic imaging with single-pixel detection,enabled by spatially optical modulation with synchronized temporally photoacoustic coding,allows decoding of the fine optical information from the modulated acoustic signal even when the variance of original photoacoustic signals is *** perform a proof-of-principle numerical demonstration of dual-compressed photoacoustic imaging, that resolves acoustic sub-acoustic-wavelength details with a significantly reduced number of measurements,revealing the potential for dynamic *** dual-compressed concept,which transforms unobtrusive spatial difference into spatio-temporal detectable information,can be generalized to other imaging modalities to re alize efficient,high-spatial-resolution imaging.
The memory effect in a single-crystal spin glass (Cu0.92Mn0.08) has been measured using 1 Hz ac susceptibility techniques over a temperature range of 0.4–0.7Tg, and a model of the memory effect has been developed. A ...
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The memory effect in a single-crystal spin glass (Cu0.92Mn0.08) has been measured using 1 Hz ac susceptibility techniques over a temperature range of 0.4–0.7Tg, and a model of the memory effect has been developed. A double-waiting-time protocol is carried out where the spin glass is first allowed to age at a temperature below Tg, followed by a second aging at a lower temperature, Tw2, after it has fully rejuvenated. The model is based on calculating typical coincident growth of correlated regions at the two temperatures. It accounts for the absolute magnitude of the memory effect as a function of both waiting times and temperatures. The data can be explained by the memory loss being a function of the relative change in the correlated volume at the first waiting temperature because of the growth in the correlations at the second waiting temperature.
As global population rises,accompanied by escalating environmental pollution and climate change,numerous countries find themselves grappling with an acute scarcity of natural freshwater resources^([1]).Seawater desali...
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As global population rises,accompanied by escalating environmental pollution and climate change,numerous countries find themselves grappling with an acute scarcity of natural freshwater resources^([1]).Seawater desalination presents a compelling solution to this looming crisis,especially considering the oceans are Earth’s largest water reservoir^([2]).
All-perovskite tandem solar cells(TSCs) consist of a wide-bandgap(WBG,1.75-1.8 eV) top subcell and a low-bandgap(LBG,1.2-1.3 eV) bottom subcell,exhibit superior power conversion efficiencies(PCEs)compared to single-ju...
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All-perovskite tandem solar cells(TSCs) consist of a wide-bandgap(WBG,1.75-1.8 eV) top subcell and a low-bandgap(LBG,1.2-1.3 eV) bottom subcell,exhibit superior power conversion efficiencies(PCEs)compared to single-junction perovskite solar cells(PSCs).In addition,the advantages of lowtemperature solution preparation and low manufactu ring cost make the all-perovskite tandem solar cells widely concerned,and are considered to be one of the most potential next-generation high-performance thin film photovoltaic *** this perspective,we briefly summarize the state-of-the-art advances in monolithic all-perovskite TSCs focusing on the following aspects:LBG perovskite bottom subcells,WBG perovskite top subcells,and interconnecting layers(ICLs).We then discuss the primary strategies to improve their performa nce and finally highlight the perspective regarding the achievement of efficient and stable all-perovskite tandems.
Xenotime rare-earth(RE)phosphates are emerging as promising materials for environmental barrier coatings(EBCs)for SiC-based ceramic-matrix composites(CMCs)because of their close coefficients of thermal expansion(CTEs)...
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Xenotime rare-earth(RE)phosphates are emerging as promising materials for environmental barrier coatings(EBCs)for SiC-based ceramic-matrix composites(CMCs)because of their close coefficients of thermal expansion(CTEs)and resistance to calcium-magnesium-alumina-silicate(CMAS)*** this work,high-entropy(HE)(Sc_(0.2)Lu_(0.2)Yb_(0.2)Er_(0.2)Y_(0.2))PO_(4) and five single-component REPO4(RE=Sc,Lu,Yb,Er,and Y)compounds were synthesized,and their stability,thermal properties,and CMAS corrosion resistance were *** CTE values of four REPO_(4) compounds(RE=Lu,Yb,Er,and Y;~(5.6-6)×10^(−6)℃^(−1))are close to those of SiC-CMC((4.5-5.5)×10^(−6)℃^(−1)),whereas ScPO_(4)(6.98×10^(−6)℃^(−1))and HE(5RE_(0.2))PO_(4)(6.39×10^(−6)℃^(−1))have slightly higher values in the temperature range of 200-1300℃.HE phosphate has the lowest thermal conductivity due to its size and mass *** CMAS corrosion tests at 1300℃ for 5,45,and 96 h revealed that all RE phosphates formed a continuous and dense reaction layer predominantly composed of Ca_(8)MgRE(PO_(4))_(7),effectively impeding CMAS ***,REPO_(4) with smaller RE³−cations displays a slower reaction rate and reduced corrosion kinetics,as evidenced by the smaller thickness of the reaction layer.A larger negative difference in the optical basicity(OB)value between REPO_(4) and CMAS signifies greater corrosion resistance.A mechanistic understanding of CMAS corrosion and elucidation of the effects of critical parameters such as the ionic mass and ionic radius of RE elements on their thermal properties and CMAS corrosion kinetics are useful for the development of novel xenotime-type phosphates as EBCs for SiC-CMCs.
Emerging machine learning(ML)approaches have been adopted in various material systems to predict novel properties with the assistance of the corresponding large *** new materials,however,collecting sufficient data poi...
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Emerging machine learning(ML)approaches have been adopted in various material systems to predict novel properties with the assistance of the corresponding large *** new materials,however,collecting sufficient data points for model training is not feasible,which is the case for gold nanoparticle/polymer hybrid *** this study,an ML approach coupled with finite element modeling was proposed for predicting the optical and photothermal properties of gold nanoparticle/polymer hybrid *** datasets of the optical and photothermal properties were built using results from the ***,finite element analyses were conducted to generate synthetic data to satisfy the quality and quantity of the data required for training *** analysis and model training were performed using the datasets with and without synthetic data to evaluate their effects on predicting the performance of the ML *** relative importance of features to targets(properties)was evaluated by correlation *** models with high accuracy were obtained by training various models from conventional to newly developed ***,weaknesses,and improvement of the synthetic data addition were *** proposed workflow and framework offer reliable prediction of optical and photothermal properties over different combinations of gold nanoparticles and polymer matrices,which can be extended to include more features related to processing parameters and microstructures.
The mechanical and corrosion characteristics of aluminum alloys can be influenced not only by the addition of grain refiners but also by heat treatment that modifies the microstructure and introduces variations in the...
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With the growing interest in utilizing Mg and austenitic stainless steel(ASS)in the automotive sector,joining them together in three-sheet configuration is ***,achieving this task presents considerable challenges due ...
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With the growing interest in utilizing Mg and austenitic stainless steel(ASS)in the automotive sector,joining them together in three-sheet configuration is ***,achieving this task presents considerable challenges due to the large differences in their physical,metallurgical and mechanical *** overcome these challenges,the feasibility of using weld-bonding to join Mg alloy/ASS/ASS was *** nugget formation,interface characteristics,microstructure and mechanical properties of the joints were *** results show that the connection between the Mg alloy and upper ASS was achieved through the combined effect of the cured adhesive and weld-brazing in the weld *** the other hand,a metallurgical bond was formed at the ASS/ASS *** Mg nugget microstructure exhibited fine columar grains composed predominantly of primaryα-Mg grains along with a eutectic mixture ofα-Mg andβ-*** nugget formed at the ASS/ASS interface consisted largely of columnar grains of austenite,with some equiaxed dendritic grains formed at the centerline of the *** weld-bonded joints exhibited an average peak load and energy absorption of about 8.5 kN and 17 J,respectively(the conventional RSW joints failed with minimal or no load application).The failure mode of the joints changed with increasing welding current from interfacial failure via the Mg nugget/upper ASS interface to partial interfacial failure(part of the Mg nugget was pulled out of the Mg sheet).Both failure modes were accompanied by cohesive failure in the adhesive zone.
Large-density functional theory(DFT)databases are a treasure trove of energies,forces,and stresses that can be used to train machine-learned interatomic potentials for atomistic ***,we employ structural relaxations fr...
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Large-density functional theory(DFT)databases are a treasure trove of energies,forces,and stresses that can be used to train machine-learned interatomic potentials for atomistic ***,we employ structural relaxations from the AFLOWdatabase to train moment tensor potentials(MTPs)for four carbide systems:CHfTa,CHfZr,CMoW,and *** resulting MTPs are used to relax~6300 random symmetric structures,and are subsequently improved via active learning to generate robust potentials(RP)that can relax a wide variety of structures,and accurate potentials(AP)designed for the relaxation of low-energy *** protocol is shown to yield convex hulls that are indistinguishable from those predicted by AFLOWfor the CHfTa,CHfZr,and CTaTi systems,and in the case of the CMoW system to predict thermodynamically stable structures that are not found within AFLOW,highlighting the potential of the employed protocol within crystal structure *** of over three hundred(Mo1−xWx)C stoichiometry crystals first with the RP then with the AP yields formation enthalpies that are in excellent agreement with those obtained via DFT.
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