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The dynamical, mechanical, anisotropic, and thermodynamic properties of Mg-XL-Y (XL = Zn, Al) alloys based on three long-period stacking ordered (LPSO) phases (ie, 10H, 14H, and 18R) have been investigated systematically by first-principles calculations. The LPSO phases of Mg-XL-Y (XL = Zn, Al) alloys are thermodynamically, dynamically, and mechanically stable. The each LPSO phase of Mg–Al–Y alloys has superior mechanical properties with larger resistances to deformation under applied stress and shear pressure, stiffness, as well as hardness than those of corresponding to LPSO phases of Mg–Zn–Y alloys. According to universal elastic anisotropic index, percent shear anisotropy, 3D surface structures of Young's moulus, and sound velocities, the LPSO phases of Mg-XL-Y (XL = Zn, Al) alloys exhibit obvious anisotropy. Besides, all LPSO phases of Mg-XL-Y (XL = Zn, Al) alloys possess low lattice thermal conductivity due to the strong anharmonicity. The calculated adsorption energies indicate that the 14H(001) surface of Mg–Al–Y system at the hollow site is more sensitive to absorb O atom. • Three long-period stacking ordered (LPSO) phases (ie, 10H, 14H, and 18R) are thermodynamically, dynamically, and mechanically stable. • Each LPSO phase of Mg–Al–Y alloys has superior mechanical properties with larger resistances to deformation under applied stress and shear pressure, stiffness, as well as hardness than those of corresponding to LPSO phases of Mg–Zn–Y alloys. • LPSO phases of Mg-XL-Y (XL = Zn, Al) alloys exhibit obvious anisotropy and low lattice thermal conductivity. [ABSTRACT FROM AUTHOR]

The crystal structures, mechanical properties, anisotropic properties, and lattice thermal conductivities of Mg–Bi alloys have been investigated by particle swarm optimization structure prediction method and first-principles calculations. Apart from the well-known stoichiometry of Mg 3 Bi 2 , the novel stable stoichiometry of Mg 4 Bi, as well as several metastable stoichiometries (i.e., Mg 3 Bi, Mg 2 Bi, and MgBi) are predicted. Meanwhile, the calculated phonon dispersion curves and elastic constants show that the above five Mg–Bi alloys are dynamically and mechanically stable, respectively. Moreover, the calculated mechanical properties indicate that the studied Mg–Bi alloys with various stoichiometries behave ductility. Simultaneously, they exhibit obvious anisotropic characters and the degree of anisotropy follows the order of MgBi > Mg 2 Bi > Mg 3 Bi > Mg 4 Bi > Mg 3 Bi 2. More importantly, the minimum lattice thermal conductivities of MgBi and Mg 2 Bi are smaller than that of the well-known Mg 3 Bi 2. The adsorption of O atom on the Mg 3 Bi (001) surface is more sensitive compared with other four Mg–Bi (001) surfaces. • Apart from the well-known stoichiometry of Mg 3 Bi 2 , the novel stable stoichiometry of Mg 4 Bi, as well as several metastable stoichiometries (i.e., Mg 3 Bi, Mg 2 Bi, and MgBi) are predicted. • The five Mg–Bi alloys are dynamically and mechanically stable. • The five Mg–Bi alloys behave ductility and obvious anisotropy. • The minimum lattice thermal conductivities of MgBi and Mg 2 Bi are smaller than that of Mg 3 Bi 2. [ABSTRACT FROM AUTHOR]

• Interfacial contact between PTL/CL affects both electrical resistance and heat conduction. • Imperfect contact at anode PTL results in current density dependency of HFR. • Effects of different operating protocols are studied. • Optimized contact is required to obtain improved and reliable performance. Proton exchange membrane water electrolysis (PEMWE) cells have made significant progress with regards to their performance, durability and cost reduction in the past few decades. Although the interfacial contacts between each PEMWE cell component have a significant impact on cell performance and durability, their effects are still not fully investigated. In this study, the interfacial contact between porous transport layers (PTLs) and catalyst layers (CLs) is systematically studied utilizing various test protocols and conditions, including step scan, dynamic sweep scan, galvanostatic and potentiostatic control. Poorly designed electrical contact at the anode PTL/CL interface will lead to an increased electrical resistance, and results in a high frequency resistance (HFR) and dependency on current density. In addition, the data suggest that an uncoated PTL/CL interfacial contact causes an inhomogeneous temperature distribution on the micro-scale, which may accelerate cell degradation. Improving the interfacial contact by applying platinum group metal coatings, such as thin film Ir coatings, reduces the cell ohmic resistance and improves the heat management. This study gives insights into the effects of interfacial contacts, test protocols and impact on operation conditions. The impact of PTL microstructure as function of PTL thickness is elucidated. It emphasizes the importance of an optimized interfacial contact and provides guidelines for PEM electrolysis measurement protocols. [Display omitted]. [ABSTRACT FROM AUTHOR]

Soil temperature is a key parameter in the soil–vegetation–atmosphere system. It plays an important role in the land surface water and energy cycles, and has a major influence on vegetation growth and other hydrological aspects. We evaluated the accuracy of the soil temperature profiles from the Global Land Data Assimilation System (GLDAS) using nine observational networks across the world and aimed to find a reliable global soil temperature profile dataset for future hydrological and ecological studies. In general, the soil temperature profile data generated by the Noah model driven by the GLDAS forcing data (GLDAS_Noah10 and GLDAS_Noah10_v2) were found to have high skills in terms of daily, monthly, and mean seasonal variations, indicated by smaller bias and root-mean-square-error (RMSE) (both <3 °C) and correlation coefficients larger than 0.90. Conversely, the Community Land Model (CLM) results (GLDAS_CLM10) generally showed larger bias and RMSE (both >4 °C). Further analysis showed that the overestimation by GLDAS_CLM10 was mainly caused by overestimation of the ground heat flux, determined by the thermal conductivity parameterization scheme, whereas the underestimation by GLDAS_Noah10 was due to underestimation of downward longwave radiation from the forcing data. Thus, more accurate forcing data should be required for the Noah model and an improved thermal parameterization scheme should be developed for the CLM. These approaches will improve the accuracy of simulated soil temperatures. To our knowledge, it is the first study to evaluate the GLDAS soil temperatures with comprehensive in situ observations across the world, and has a potential to facilitate an overall improvement of the GLDAS products (not only soil temperatures but also the related energy and water fluxes) as well as a refinement of the land surface parameterization used in GLDAS. [ABSTRACT FROM AUTHOR]

• A facile microfluidic approach for controllable encapsulation of phase change material is presented. • High monodisperse PCM capsules with various reliable structures are prepared by adjusting flow rates. • Multilayer graphene is introduced into the pure PCM (RT25) modify the thermo-regulation ability. • Current PCM capsules provide new options for the real thermo-regulation and energy conservation. In this work, a facile microfluidic approach for controllable encapsulation of phase change material is presented to fabricate robust PCM capsules. The multilayer graphene is also introduced into the pure PCM (RT25) for improving the thermal conductivity of the PCM, so as to modify the thermo-regulation ability of the PCM capsules. Systematical experimental tests indicate that, via the current approach, PCM can be controllably encapsulated into every capsule with high monodispersity (coefficient of variation (C.V.) ≤ 2%) and reliable core-shell structure. The size and the core/shell proportion of the PCM capsules (i.e., the thermo-regulation ability) can be controlled precisely by adjusting the flow rates of the inner and outer phases. Especially, the thermal conductivity of PCM capsules can be improved by adding the multilayer graphene (≤ 2 wt%) with negligible degeneration of energy storage capacity less than 5%, which makes the PCM capsules response faster to the change of ambient thermal environment. The prepared PCM capsules provide new options for the real thermo-regulation and energy conservation. [ABSTRACT FROM AUTHOR]

Large size high transparent TSAG and TSLAG single crystals of Ø 65 mm × 70 mm have been grown successfully by the Cz method. The refractive indices at 473, 532, 632.8 and 1064 nm are 1.9214 - 1.8817 for TSAG and 1.9242 - 1.8841 for TSLAG. Their Sellmeier equations are fitted. The average thermal expansion coefficients of TSAG and TSLAG at 300 – 373 K, 300 – 473 K, 300 – 573 K, 300 – 673 K, and 300 – 773 K are measured. The values of thermal expansion coefficients of TSAG and TLSAG crystals coincide within the measurement error (differ by 0.3–0.4%). The thermal diffusivity values of TSAG and TSLAG are 1.454 and 1.418 mm2 s−1 at 300 K, respectively. Calculated with the specific heat results, the values of thermal conductivity of TSAG and TSLAG are 4.45 and 4.20 W (m K)−1 at 300 K. Moreover, the Verdet constants of TSAG are 218, 152, and 65 rad/m/T at 532, 633, and 1064 nm, while those of TSLAG are 246, 146, and 56 rad/m/T, respectively. In further, the relationships between Verdet constant and wavelength of TSAG and TSLAG are obtained. • TSAG and TSLAG with large size of Ø 65 mm × 70 mm were grown successfully by the Cz method. • The refractive indices at 473, 532, 632.8 and 1064 nm are 1.9214 - 1.8817 for TSAG and 1.9242 - 1.8841 for TSLAG. • The thermal properties of TSAG and TSLAG are studied and compared with each other in detail. • The relationship of TSAG and TSLAG between Verdet constant and wavelength are fitted. [ABSTRACT FROM AUTHOR]