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This study aims to analyse the relationship between body mass index and foot length in Chinese adolescents and to provide theoretical guidance for preventing a flat foot in Chinese adolescents. This study recruited 1477 students aged 14–23 years. The participants' height, weight, and body mass index were measured, as well as baseline data, including age, gender and foot length. Differences in foot length (bilateral) and flat foot distribution were statistically significant except for the normal foot and high arch foot distribution based on different body mass index groups. Linear correlation analysis demonstrated that body height, weight and body mass index were positively correlated with bilateral foot length regardless of gender. Body mass index acted as a risk factor for flat foot (bilateral) through disordered multi-classification logistic regression analysis. Body mass index was positively correlated with left and right foot length regardless of gender and acted as a risk factor for a flat foot in Chinese adolescents. Practitioner summary: Significant differences exist in the anthropometric data of various races and ethnic groups. The study was investigated in the form of a cross-sectional study. BMI was positively correlated with bilateral foot length and acted as a risk factor for a flat foot in Chinese adolescents. [ABSTRACT FROM AUTHOR]

Controllable synthesis of well‐defined supported intermetallic catalysts is desirable because of their unique properties in physical chemistry. To accurately pinpoint the evolution of such materials at an atomic‐scale, especially clarification of the initial state under a particular chemical environment, will facilitate rational design and optimal synthesis of such catalysts. The dynamic formation of a ZnO‐supported PdZn catalyst is presented, whereby detailed analyses of in situ transmission electron microscopy, electron energy‐loss spectroscopy, and in situ X‐ray diffraction are combined to form a nanoscale understanding of PdZn phase transitions under realistic catalytic conditions. Remarkably, introduction of atoms (H and Zn in sequence) into the Pd matrix was initially observed. The resultant PdHx is an intermediate phase in the intermetallic formation process. The evolution of PdHx in the PdZn catalyst initializes at the PdHx/ZnO interfaces, and proceeds along the PdHx ⟨111⟩ direction. A palladium catalyst supported on ZnO is monitored in situ and in chemical environments relevant to catalysis. Structural evolution of PdZn intermetallic metal nanoparticles (NPs), visualized at an atomic scale, reveals the evolution of a PdHx intermediary species at the interface between PdHx and the ZnO support. [ABSTRACT FROM AUTHOR]

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As a prerequisite elementary step, carburization of iron oxides to form iron carbides is critically important to display activity for iron‐based Fischer–Tropsch synthesis catalysts. The positive role of the Cu promoter to advocate the reduction of the iron oxides has long been known. Nevertheless, its complex influence along the carburization of catalyst precursors remains controversial. Here, we resolve this decades‐long question by using a state‐of‐the‐art in situ X‐ray diffraction (XRD) method to elucidate the multi‐role of Cu promoter in modulation of carburization rate, composition of post‐carburization samples, and morphology evolution of prepared iron carbide particles under CO/He (v/v=2 %/98 %) and H2/CO/He (v/v/v=8 %/2 %/90 %) gaseous environment, by excluding the possible interference from promoter components other than Cu. We anticipate that this study enriches current tool box in the research of a specific promoter of the Fischer‐Tropsch synthesis catalysts. In situ seeing is believing: The complex influence of Cu promoter along the carburization of iron catalyst precursors has been elucidated by using a state‐of‐the‐art in situ X‐ray diffraction (XRD) method. Particularly, the multi‐role of Cu promoter in modulation of carburization rate, composition of post‐carburization samples, and morphology evolution of prepared iron carbide particles under CO/He (v/v=2 %/98 %) and H2/CO/He (v/v/v=8 %/2 %/90 %) gaseous environment, by excluding the possible interference from promoter components other than Cu. [ABSTRACT FROM AUTHOR]

A study of the promotional effect of potassium on the carburization behavior of a series of spray-dried precipitated Fe2O3 catalysts (100 Fe, 100 Fe/0.52 K, 100 Fe/1.54 K, and 100 Fe/2.4 K) has been performed by using in situ XRD. The average crystallite size evolution for species such as α-Fe2O3, Fe3O4, χ-Fe5C2, and θ-Fe3C were followed. The potassium promoter clearly inhibits the reduction of α-Fe2O3 to Fe3O4, where the decreasing binding energy in the Fe 2p3/2, O 1s and K 2p3/2 spectra from X-ray photoelectron spectroscopy (XPS) suggests an electron density increase in Fe and O upon potassium promotion, leading to the enhanced covalency in the Fe−O bond. In terms of crystallite size during carburization, an optimum potassium loading exists in catalyst 100 Fe/0.52 K, which shows the fastest reduction to Fe3O4 with minimum crystallite sizes of around 7 to 15 nm. Potassium has no clear effect in determining the final crystallite size of χ-Fe5C2. An arch-shaped curve in the evolution of crystallite size of the Fe3O4 intermediate was observed, which can be explained by the activation energy difference between the bidirectional steps of the outward oxygen diffusion and the inward carbon diffusion. [ABSTRACT FROM AUTHOR]

Abstract: Yttria stabilized zirconia (YSZ) has a high oxide ion conductivity at high temperatures. Some rare earth elements (e.g., Yb, Sc, Dy) with similar cation radii to Zr4+ can dissolve into ZrO2, increasing its vacancy concentration and crystal lattice distortion, and therefore enhancing its conductivity and lowering the activation energy. It is expected this material could be used as intermediate temperature electrolyte. In the present work, YSZ electrolyte materials doped by multi-elements (Sc2O3 or Dy2O3 and Yb2O3) were prepared by high temperature solid-state method. The high temperature conductivity was improved obviously, reaching 0.18S/cm at 1000°C, but the density and mechanical properties of sintered materials were not sufficiently high. It is found that sinterability and mechanical properties could be improved by inclusion of a small amount of Al2O3 and/or CaO into the multi-elements doped YSZ materials and our results proved it. The results showed density and bending strength of sintered bodies were enhanced by Al2O3 addition by 4.6% and 30%, respectively, while the conductivity did not degrade remarkably. But the degradation in bending strength and conductivity resulting from the CaO addition happened due to the second phase formed at the grain boundary. XRD patterns showed that all samples had cubic fluorite structure and crystalline lattice parameter was increased. SEM photographs obviously revealed the grain growth for the samples with CaO inclusion. [Copyright &y& Elsevier]

Leaping the dragon gate Nanoscale phase transitions occur for a ZnO‐supported PdZn intermetallic under realistic acetylene hydrogenation conditions. In their Communication on page 4232 ff., D. S. Su, W. Zhang, B. Zhang, et al. observe the evolution of a PdHx intermediary species at the interface between PdHx and a ZnO support using in situ X‐ray diffraction and transmission electron microscopy. According to Chinese legend, Yulong carp will transform into dragons if they climb a waterfall. [ABSTRACT FROM AUTHOR]

Copyright of Angewandte Chemie is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Controllable synthesis of well‐defined supported intermetallic catalysts is desirable because of their unique properties in physical chemistry. To accurately pinpoint the evolution of such materials at an atomic‐scale, especially clarification of the initial state under a particular chemical environment, will facilitate rational design and optimal synthesis of such catalysts. The dynamic formation of a ZnO‐supported PdZn catalyst is presented, whereby detailed analyses of in situ transmission electron microscopy, electron energy‐loss spectroscopy, and in situ X‐ray diffraction are combined to form a nanoscale understanding of PdZn phase transitions under realistic catalytic conditions. Remarkably, introduction of atoms (H and Zn in sequence) into the Pd matrix was initially observed. The resultant PdHx is an intermediate phase in the intermetallic formation process. The evolution of PdHx in the PdZn catalyst initializes at the PdHx/ZnO interfaces, and proceeds along the PdHx ⟨111⟩ direction. [ABSTRACT FROM AUTHOR]

Controllable synthesis of well‐defined supported intermetallic catalysts is desirable because of their unique properties in physical chemistry. To accurately pinpoint the evolution of such materials at an atomic‐scale, especially clarification of the initial state under a particular chemical environment, will facilitate rational design and optimal synthesis of such catalysts. The dynamic formation of a ZnO‐supported PdZn catalyst is presented, whereby detailed analyses of in situ transmission electron microscopy, electron energy‐loss spectroscopy, and in situ X‐ray diffraction are combined to form a nanoscale understanding of PdZn phase transitions under realistic catalytic conditions. Remarkably, introduction of atoms (H and Zn in sequence) into the Pd matrix was initially observed. The resultant PdHx is an intermediate phase in the intermetallic formation process. The evolution of PdHx in the PdZn catalyst initializes at the PdHx/ZnO interfaces, and proceeds along the PdHx ⟨111⟩ direction. A palladium catalyst supported on ZnO is monitored in situ and in chemical environments relevant to catalysis. Structural evolution of PdZn intermetallic metal nanoparticles (NPs), visualized at an atomic scale, reveals the evolution of a PdHx intermediary species at the interface between PdHx and the ZnO support. [ABSTRACT FROM AUTHOR]

Controllable synthesis of well-defined supported intermetallic catalysts is desirable because of their unique properties in physical chemistry. To accurately pinpoint the evolution of such materials at an atomic-scale, especially clarification of the initial state under a particular chemical environment, will facilitate rational design and optimal synthesis of such catalysts. The dynamic formation of a ZnO-supported PdZn catalyst is presented, whereby detailed analyses of in situ transmission electron microscopy, electron energy-loss spectroscopy, and in situ X-ray diffraction are combined to form a nanoscale understanding of PdZn phase transitions under realistic catalytic conditions. Remarkably, introduction of atoms (H and Zn in sequence) into the Pd matrix was initially observed. The resultant PdH x is an intermediate phase in the intermetallic formation process. The evolution of PdH x in the PdZn catalyst initializes at the PdH x /ZnO interfaces, and proceeds along the PdH x ⟨111⟩ direction., (© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)