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Exploring highly active, low-cost electrocatalysts for the oxygen evolution reaction (OER) is of great significance but still a major challenge. Herein, we synthesized Ni(OH)2@Ni(Fe)OOH with a sea urchin-like structure on a nickel foam via a simple hydrothermal and subsequent soaking process. Experimental results indicate that incorporation of Fe into Ni(OH)2 is favorable for modulating the electronic structure as well as achieving faster electron transfer and improved intrinsic activity, thereby leading to excellent OER activity. The optimized Ni(OH)2@Ni(Fe)OOH electrocatalyst exhibits superior OER activity with overpotentials of 245 and 310 mV at 10 and 100 mA cm−2, respectively, and a small Tafel slope of 40.7 mV dec−1 and high stability over 100 h, which is more than that of benchmark RuO2 and several control samples without the introduction of Fe. More importantly, the overall water splitting system using Ni(OH)2@Ni(Fe)OOH-100 as the anode and Pt/C as the cathode only requires a cell voltage of 1.54 V to afford a current density of 10 mA cm−2. This work not only demonstrates the key factor of Fe doping, but also offers a new path for the development of NiFe-based OER catalysts. [ABSTRACT FROM AUTHOR]

Developing low‐cost and exceedingly efficient electrocatalysts for oxygen evolution reaction (OER) is vital for application of hydrogen production from water splitting. Herein, three different nickel sulfides on nickel foam were fabricated via a simple sulfuring the as‐formed Ni‐MOF with different sulfide as the sulfur source. The effect of sulfur source on OER performance, morphology and structure of the as‐prepared product are well discussed. The optimized Ni‐MOF/NF‐SS deliver overpotentials of 253 and 330 mV to reach current densities of 10 and 100 mA cm−2 with a small Tafel slope of 70.9 mVdec−1, and stability of over 50 h. This work provides insights into the relationship between the OER activity and the structures of nickel sulfides, but also affords a new route to fabricate nickel sulfides‐based electrocatalysts for OER. [ABSTRACT FROM AUTHOR]

Facilitating the surface reconstruction of pre-catalysts has been considered an effective strategy for constructing low-cost and highly efficient OER electrocatalysts. Metal doping is a feasible way to activate the surface reconstruction, thus enhancing the OER performance. Herein, we report a facile hydrothermal method to synthesize a series of Zn-doped Ni-MOF on nickel foam (NiZn-MOF/NF) as promising pre-catalysts toward the oxygen evolution reaction (OER). The Zn leaching of NiZn-MOF/NF can promote the surface self-reconstruction of NiZn-MOF/NF into oxygen-vacancy-rich NiOOH after electrochemical activation. Benefiting from the optimized electronic structure, abundant defects, more accessible active sites, and enhanced electrical conductivity, the reconstructed metal oxyhydroxide hybrids exhibit better electrocatalytic activity than the catalysts transformed from Ni-MOF/NF without Zn doping. The optimized NiZn-MOF/NF-OH as an OER catalyst has an overpotential of 336 mV at 100 mA cm−2, and a Tafel slope of 65.9 mV dec−1, as well as stability over 12 h. This work reveals that Zn cation-doping/leaching induces the surface reconstruction of pre-catalysts for enhanced oxygen catalytic activity, which provides a new approach for the development of advanced electrocatalysts. [ABSTRACT FROM AUTHOR]

In this work, we demonstrated a novel, sensitive and effective fluorescent naringin (NRG) and naringenin (NRGe) detection method using polymethionine nanoparticles (PMNPs) as a fluorescent nanoprobe. The PMNPs were first synthesized by autopolymerization of methionine at 90 °C when trace copper ions existed. The as-prepared PMNPs were thoroughly characterized by transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FT-IR), gel permeation chromatograph (GPC), nuclear magnetic resonance spectroscopy (NMR), transient and steady-state fluorescence and UV–Vis absorption spectroscopy. The quenching mechanism was attributed to the inner filter effect (IFE). Moreover, the developed assay was used successfully to detect NRG and NRGe in real samples of citrus fruits, illustrating that this detection method has great potential application in the field of citrus fruits analysis. [ABSTRACT FROM AUTHOR]

Teacher feedback in reading class is closely associated with students' reading achievement. However, the underlying mechanisms of their relationship has been underexplored, especially in cross-cultural contexts. Using Control Value Theory of Achievement Emotions (CVTAE), this study tested the cross-cultural generalizability of reading enjoyment as a mediator between teacher feedback and reading achievement among 536,848 15-year-olds from 75 countries/economies in PISA 2018. Multilevel structural equation modeling (MSEM) results showed that students who perceived more teacher feedback gained more enjoyment in reading activities, and thus scored higher in reading. This relationship was confirmed in 73 out of 75 countries/economies. However, at the school level, this association existed in only 25 of 75 countries/economies. These findings indicate cross-cultural generalization of reading enjoyment as a mediator between teacher feedback and reading achievement only at the student level, which not only provides cross-cultural evidence for CVTAE, but also sheds light on reading instruction of adolescents. [ABSTRACT FROM AUTHOR]

The correlation between motivational beliefs and foreign language learning has been widely explored. However, there has been little investigation of this link among learners with different foreign language levels. Based on expectancy-value theory (EVT), this research examined the association between motivational beliefs and English achievement of 11,854 Chinese secondary students. Data were collected using students' self-reported English self-efficacy, intrinsic value, utility value, and English achievement test. The results of ANOVA showed that self-efficacy, intrinsic value, and utility value of high-achieving English learners were significantly higher than that of medium-achieving ones, followed by low-achieving ones. Multiple regression analysis demonstrated that after controlling for socioeconomic status and gender, intrinsic value was most correlated with high- and medium-achieving learners' English achievement, followed by self-efficacy, while utility value was not significantly associated with English achievement of the two groups. In addition, utility value was most strongly related with low-achieving learners' English achievement, followed by intrinsic value, but self-efficacy was not positively linked with their English achievement. These findings not only extend EVT and validate the situative perspective of motivation research, but also have practical implications for foreign language education. [ABSTRACT FROM AUTHOR]

HBEA zeolite modified with highly electronegative cations is a highly efficient and reusable catalyst for the nitration of naphthalene with nitric acid, which has been successfully prepared in this work. Catalytic selective mononitration of naphthalene was investigated. The ratio of 1-nitronaphthalene isomer to 2-nitronaphthalene could reach 19.2, with a moderate yield of 68.2%, when the reaction was carried out in 1,2-dichloroethane, with 1.0 mmol naphthalene, 0.22 mL nitric acid (95%), and 0.10 g HBEA-25 at −15 °C. The effects of reaction temperature and the quantity of zeolites on 1-nitronaphthalene were also studied. The catalyst is readily recyclable, and we believe this to be a major step forward in the area of clean technology for aromatic nitration. [ABSTRACT FROM AUTHOR]

Al matrix composite, reinforced with the in situ synthesized 3C–SiC, MgAl2O4, and MgO grains, was produced via the casting process using phenolic resin pyrolysis products in flash mode. The contents and microstructure of the composites' fracture characteristics were analyzed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Mechanical properties were tested by universal testing machine. Owing to the strong propulsion formed in turbulent flow in the pyrolysis process, nano-ceramic grains were formed in the resin pyrolysis process and simultaneously were homogeneously scattered in the alloy matrix. Thermodynamic calculation supported that the gas products, as carbon and oxygen sources, had a different chemical activity on in situ growth. In addition, ceramic (3C–SiC, MgAl2O4, and MgO) grains have discrepant contents. Resin pyrolysis in the molten alloy decreased oxide slag but increased pores in the alloy matrix. Tensile strength (142.6 ± 3.5 MPa) had no change due to the cooperative action of increased pores and fine grains; the bending and compression strength was increasing under increased contents of ceramic grains; the maximum bending strength was 378.2 MPa in 1.5% resin-added samples; and the maximum compression strength was 299.4 MPa. Lath-shaped Si was the primary effect factor of mechanical properties. The failure mechanism was controlled by transcrystalline rupture mechanism. We explain that the effects of the ceramic grains formed in the hot process at the condition of the resin exist in mold or other accessory materials. Meanwhile, a novel ceramic-reinforced Al matrix was provided. The organic gas was an excellent source of carbon, nitrogen, and oxygen to in situ ceramic grains in Al alloy. [ABSTRACT FROM AUTHOR]

Background: The aim of this study is to evaluates the hypothesis that Hh pathway activation occurs in the Fah -/- Nod/Scid mice model and plays a role in regulating liver regeneration after functional human hepatocytes xenograft., Methods: Fah -/- Nod/Scid mice were established in Shandong Cancer Hospital affiliated to Shandong University. Xeno-regeneration of Fah -/- Nod/Scid mice livers was then transplanted by human hepatocytes . Hh signaling pathway associated factors were detected by RT-PCR and western blot. All statistical calculations were carried out using the SPSS.16.0 software., Results: Fah -/- mice were healthy and reproduced normally while treated with NTBC. NTBC-OFF Fah -/- mice with HHT gradually gained weight by six weeks after human hepatocyte transplantation. NTBC-OFF Fah -/- mice causes a progressive increase in ALT, AST, GGT and AP, which were used to monitor hepatocyte inflammation. However, liver function in NTBC-OFF Fah Fah -/- mice with HHT returned to normal. Hedgehog pathway activation and Hh-target genes were enhanced follows human hepatocytes transplantation which indicated liver regeneration associated closely with Hh signaling pathway. Moreover, Hh signaling was inhibited by cyclopamine after HHT., Conclusions: The current study provides novel evidence that Hedgehog signaling pathway regulation is required for optimal regeneration of NTBC OFF Fah -/- mice with HHT., Competing Interests: None., (IJCEP Copyright © 2017.)