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Hashing has been extensively studied for large-scale cross-modal retrieval. However, there are still some unexplored issues with existing methods. First, both the initially-provided similarity graph and one-hot label vector only logically describe the yes or no information, which cannot exactly reflect the correlation between instances. Second, all bits in a binary code contribute equally to Hamming distance, which limits its discriminability to preserve refined semantics. To address these limitations, this paper presents a new method, dubbed Weighted Cross-Modal Hashing (WCMH). It introduces the topological structure of categories to enhance the logical labels, i.e., to recover the real-valued distribution of categories. Moreover, we design a weighted Hamming distance that can enlarge the range of distance values by adaptively learning the weights of different hash bits. In light of this, more discriminative information is embedded into hash codes, and the enhanced semantics can be preserved as much as possible. Extensive experiments validate the superior performance of our WCMH, in comparison with some state-of-the-art cross-modal hashing approaches. [ABSTRACT FROM AUTHOR]

Transition Metal Oxides (TMOs) have drawn significant attention due to their diverse range of properties and applications. The partially filled d orbitals of the transition metal ions, with highly electronegative oxygen atoms, give rise to unique electronic structures that lead to multiple applications due to their magnetic, optical, and structural properties. These properties have a direct influence on chemical reactions that enable tailoring materials for specific applications in catalysis, such as electrocatalysis and photocatalysis. While the potential of TMOs is promising, their development for enhanced functional properties poses numerous challenges. Among these challenges, identifying the appropriate synthesis processes and employing optimal characterization techniques are crucial. In this comprehensive review, an overview of recent trends and challenges in the synthesis and characterization of highly functional TMOs as well as ceramics will be covered with emphasis on catalytic applications. Mesoporous materials play a key role in augmenting their functionality for various applications and will be covered. Ab-initio modeling aspects for the design and development of novel TMO will be also discussed. [ABSTRACT FROM AUTHOR]

For the catalyst for water splitting, low overpotential and longer stability is very important. Here, we developed a simple strategy to prepare an efficient catalyst for oxygen evolution by partially phosphating NiFe-LDH and then etching and growing Prussian blue analogues on it. Benefiting from its unique hierarchical structure, the synthesized NiFeCo PBA-NiFeP catalyst showed excellent electrocatalytic performance in 1 M KOH. At 100 mA/cm2, the overpotential of the oxygen evolution reaction (OER) is only 245 mV and exhibits stability for over 50 h. This is superior to most of the OER catalysts reported so far. Its excellent performance is due to its unique hierarchical structure and the synergistic effect between polymetals, which enables it to have abundant active sites and efficient electron transfer. This controllable and universal strategy will provide a new idea for developing interfacial composites and preparing high efficiency electrocatalysts. • A new NiFeCo-PBA-NiFeP composite was prepared by hydrothermal-phosphating-etching process. • The unique hierarchical structure facilitates gas release and contact between the active site and the solution. • The synergistic effect between multiple metals improves the OER properties of the materials. • The combination of NiFeP and NiFeCo PBA improves the OER performance of the material. [ABSTRACT FROM AUTHOR]

[Display omitted] • Heterogeneous MnNiCoP/FeOOH was successfully prepared by electrodeposition phosphating electrodeposition. • The interfacial synergism results in excellent HER and OER electrocatalytic activity and stability. • The catalyst can provide 1.627 V battery voltage at 100 mA cm−2, and shows good stability and durability. The production of three-dimensional heterogeneous structures is a vital approach for the creation of high-performance bifunctional electrocatalysts. Herein, three-dimensional heterostructure MnNiCoP/FeOOH (MNC-P/FeOOH) supported by Ni foam was prepared by simple electrodeposition and phosphorylation as a bifunctional electrocatalyst. The results showed that the required overpotential for MNC-P/FeOOH catalyst to reach 100 mA cm−2 current density was 124 mV and 251 mV in 1.0 M KOH solution, respectively. Construction of heterojunction not only improves the OER performance of MnNiCoP, but also reduces the potential required to drive the integral water splitting at 100 mA cm−2 current density. The electrocatalytic activity of MNC-P/FeOOH is greatly increased due to a distinctive interface synergy and strong electronic contacts in the MNC-P/FeOOH heterojunction. This design approach of bifunctional transition metal phosphides provides a potential route to achieve total water splitting. [ABSTRACT FROM AUTHOR]