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Hydrodynamic considerations and design concepts for optimal thermal compressors
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Designing sub-20 nm self-assembled nanocarriers for small molecule delivery: Interplay among structu
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Energetic design of grain boundary networks for toughening of nanocrystalline oxides
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Gaseous isostatic forging: Design and application to powder metallurgy Ti-6Al-4V
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Optimization through classical design of experiments (DOE): An investigation on the performance of different factorial designs for multi-objective optimization of complex systems
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A facile cathode design combining Ni-rich layered oxides with Li-rich layered oxides for lithium-ion batteries
A facile synthesis method was developed to prepare xLi 2 MnO 3 ·(1-x)LiNi 0.7 Co 0.15 Mn 0.15 O 2 (x = 0, 0.03, 0.07, 0.10, 0.20, and 0.30 as molar ratio) cathode materials, combining the advantages of high specific capacity from Ni-rich layered phase and surface chemical stability from Li-rich layered phase. X-ray diffraction (XRD), high resolution transmission electron microscope (HRTEM) and electrochemical charge/discharge performance confirm the formation of a Li-rich layered phase with C2/m symmetry. Most importantly, high-angle annular dark-field (HAADF) scanning transmission electron microscopy (STEM) reveals a spatial relationship that Li-rich nano-domain islands are integrated into a conventional Ni-rich layered matrix (R$\bar{3}$m). This is the first time that Li-rich phase has been directly observed inside a particle at the nano-scale, when the overall composition of layered compounds (Li 1+δ Ni x Mn y M 1-x-y-δ O 2 , M refers to transition metal elements) is Ni-rich (x > 0.5) rather than Mn-rich (y > 0.5). Remarkably, xLi 2 MnO 3 ·(1-x)LiNi 0.7 Co 0.15 Mn 0.15 O 2 cathode with optimized x value shows superior electrochemical performance at C/3, i.e., 170 mA h g -1 with 90.3 % of capacity retention after 400 cycles at 25 °C and 164 mA h g -1 with 81.3 % capacity retention after 200 cycles at 55 °C.
Interfacial design and strengthening mechanisms of AZ91 alloy reinforced with in-situ reduced graphene oxide
Highlights: • An in-situ process was developed to synthesize magnesium alloy composite reinforced by graphene. • Microstructure and phase composition of oxide films were investigated by OM, SEM, EDS and XRD analysis. • The interfacial structure of Mg composites reinforced with reduced graphene oxide was characterized. • The interfacial reaction mechanisms between GO (graphene oxide) and the Mg metal was studied. - Abstract: This work highlights to develop an in-situ process to disperse uniformly graphene possessing good interfacial bonds with the matrix of Mg alloy. A homogeneous distribution of graphene in the matrix has been successfully obtained through in-situ reduction of graphene oxide (RGO) by sintering process after the graphene oxide (GO) was uniformly dispersed in AZ91 powders. The interface product nano-sized MgO can significantly improve the interfacial bonding strength between RGO and α-Mg with analysis by transmission electron microscopy. The orientation relationships of ( 2-bar 00){sub MgO}//( 1-bar 10 2-bar ){sub α‐Mg} and [011]{sub MgO}//[2 4-bar 2 3-bar ]{sub α‐Mg} with the semi-coherent interface characteristics were clarified for the first time at the interface of MgO/α-Mg, suggesting a good lattice space matching. By employing such process, a composite containing 0.5 wt% of GO shows an 85.7% and 61.4% increase in yield strength and elongation, respectively, over unreinforced AZ91 alloy. The underlying strengthening mechanisms of in-situ reduced graphene oxide are discussed in detail.
Inverse Design of Solid-State Materials via a Continuous Representation
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