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Analyzing and modeling the implicit semantic relationships in data sources is the key to achieving integration and sharing of heterogeneous data information. However, manual modeling of data semantics is a laborious and error-prone task that demands significant human effort and expertise. The paper proposes a novel explainable representation learning-based method that adopts an attention-based table-graph cross-modal retrieval model as a rating function during incremental search for automatic semantic modeling. Our supervised model utilizes the graph representation learning technique to extract latent semantics from data and aims to retrieve the most reliable semantic model for structured data sources. Experimental results demonstrate the effectiveness and robustness of our method. • A novel supervised table-graph cross-modal retrieval model for automatic semantic modeling. • An explainable representation learning method combining graph representation learning with an incremental search algorithm. • An attention mechanism and iterative matching method to learn fine-grained semantic matches between different modalities. • The experimental results using two different semantic labelers validate the effectiveness and robustness of our method. • The cross-modal retrieval-based method outperforms the previous best method in terms of precision, recall, and f1-score. [ABSTRACT FROM AUTHOR]

A series of γ-Al2O3-supported nickel-based catalysts were evaluated in continuous hydrogenation of toluene. Sr- and poly(ethylene glycol) 800 (PEG800)-modified Ni/ γ-Al2O3 catalysts provided the best activity with high conversion of toluene and selectivity for methylcyclohexane which was ascribed to the addition of Sr and PEG800 during the preparation process, resulting in smaller and highly dispersed Ni species on the surface and in the pores of γ-Al2O3. Furthermore, the formation of SrCO3 and NiAl2O4 is believed to be advantageous for the dispersion and stabilization of the active Ni species, accounting for its good stability. [ABSTRACT FROM AUTHOR]

The oxidant-free dehydrogenation of n-pentanol over copper based catalysts was investigated in this paper. The effect of metal modification on the activity and stability of the copper catalyst supported on γ-Al2O3 and La2O3 (Cu/ γ-Al2O3-La2O3) was clarified and a Cr modified Cu/Al2O3-La2O3 (Cu-Cr/ γ-Al2O3-La2O3) showed the best catalytic performance. The conversion of n-pentanol was 70.0% and the selectivity for n-pentanal increased to 97.1% over Cu-Cr/ γ-Al2O3-La2O3. X-ray diffraction and temperature programmed reduction of H2 indicated that the addition of Cr favors the formation and reduction of the copper oxide, and the dispersion of the active Cu0 species, accounting for the good activity and stability of this catalyst. Furthermore, the lower amount of acidic sites in Cu-Cr/ γ-Al2O3-La2O3 is suggested to suppress the dehydration in oxidant-free dehydrogenation of n-pentanol, accounting for the higher selectivity for n-pentanal. [ABSTRACT FROM AUTHOR]

[Display omitted] • AlO x -Co overlayer with 3 ∼ 5 nm thickness was modified on g-C 3 N 4 nanosheets. • Surface passivation of g-C 3 N 4 prevents serious electron-hole recombination. • Suppressed Fermi level pinning promotes photogenerated electron injection. • Cobalt doping in the overlayer facilitates charge transfer and PMS activation. • The overlayer contributes to generate surface-bound sulfate radical. Graphitic carbon nitride (g-C 3 N 4) is a promising photocatalyst for peroxymonosulfate (PMS) activation towards water treatment, but its inherent surface defects always lead to serious recombination wasting charge carriers. Herein, we constructed cobalt doped aluminum oxide overlayer (AlO x -Co) on g-C 3 N 4 nanosheets, passivating surface states for accelerated photocatalytic PMS activation. The AlO x coating prevents dangling bonds associated with surface recombination, and the Co doping reduces dynamic barrier. Thus, g-C 3 N 4 /AlO x -Co (0.0745 min−1) exhibits a 3.5 times higher activity than bare g-C 3 N 4 (0.0168 min−1) towards iohexol degradation. Systemic spectroscopic and photoelectrochemical measurements reveal that AlO x -Co overlayer could weaken in-band recombination and relieve Fermi level pinning, which facilitate the charge transfer. Meanwhile, this overlayer has suitable thickness (3 ∼ 5 nm) for feasible tunneling effects to generate surface-bound radicals. Our work attempts to overcome inefficient surface charge separation and transfer simultaneously for improved contaminant removal via photocatalytic Fenton-like catalysis. [ABSTRACT FROM AUTHOR]

A novel core-shell nanocomposite Ni-Ca@mSiO was first prepared by a modified Stöber method in this paper. It has a core-shell structure with Ni (about 8 nm in diameter) and Ca as the cores and mesoporous silica as the outer shell, as proven by the transmission electron microscopy. This nanocomposite exhibited good catalytic performance in the selective hydrogenation of benzophenone, with 96.1% conversion and 94.9% selectivity for benzhydrol under relatively mild reaction conditions. It was demonstrated that addition of small amounts of alkaline Ca can not only markedly improve the dispersion of the active species but also tune the acid-base property of this nanocomposite, resulting in the efficient suppression of benzhydrol dehydration to achieve a high selectivity. Furthermore, the core-shell nanocomposite Ni-Ca@mSiO can be recycled four runs without appreciable loss of its initial activity, more stable than the traditional supported nanocatalyst Ni-Ca/mSiO. It was suggested that the outer mesoporous silica shell of Ni-Ca@mSiO can prevent both the aggregation and the leaching of the active Ni species, accounting for its relatively good stability. [ABSTRACT FROM AUTHOR]

A series of Ni-B amorphous alloys supported on γ-AlO was prepared by an impregnation chemical reduction method and tested in the selective hydrogenation of ethyl benzoate to ethyl cyclohexane carboxylate. The effect of different metal additives on the activity of the supported Ni-B amorphous alloys was investigated. It was found that the addition of small amounts of Pd to Ni-B amorphous alloy supported on γ-AlO could markedly improve its activity and the yield of ethyl cyclohexane carboxylate can reach 88.1 % under the optimal reaction conditions. Furthermore, this catalyst could be recycled eight times without appreciable loss of its initial activity, much better than the unsupported one. The Ni-Pd-B amorphous alloy was proven to be highly dispersed on the surface and in the pores of γ-AlO, resulting in its larger BET area, more active Ni species, better stability, and hence accounting for its good catalytic performance. [ABSTRACT FROM AUTHOR]