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Rationally designing broad-spectrum photocatalysts to harvest whole visible-light region photons and enhance solar energy conversion is a “holy grail” for researchers, but is still a challenging issue. Herein, based on the common polymeric carbon nitride (PCN), a hybrid co-catalysts system comprising plasmonic Au nanoparticles (NPs) and atomically dispersed Pt single atoms (PtSAs) with different functions was constructed to address this challenge. For the dual co-catalysts decorated PCN (PtSAs–Au2.5/PCN), the PCN is photoexcited to generate electrons under UV and short-wavelength visible light, and the synergetic Au NPs and PtSAs not only accelerate charge separation and transfer though Schottky junctions and metal-support bond but also act as the co-catalysts for H2 evolution. Furthermore, the Au NPs absorb long-wavelength visible light owing to its localized surface plasmon resonance, and the adjacent PtSAs trap the plasmonic hot-electrons for H2 evolution via direct electron transfer effect. Consequently, the PtSAs–Au2.5/PCN exhibits excellent broad-spectrum photocatalytic H2 evolution activity with the H2 evolution rate of 8.8 mmol g−1 h−1 at 420 nm and 264 μmol g−1 h−1 at 550 nm, much higher than that of Au2.5/PCN and PtSAs–PCN, respectively. This work provides a new strategy to design broad-spectrum photocatalysts for energy conversion reaction.

This paper presents a sound source localization (SSL) model based on residual network and channel attention mechanism. The method takes the combination of log-Mel spectrogram and generalized cross-correlation phase transform (GCC-PHAT) as the input features, and extracts the time–frequency information by using the residual structure and channel attention mechanism, thus obtaining a better localizing performance. The residual blocks are introduced to extract deeper features, which can stack more layers for high-level features and avoid gradient vanishing or exploding at the same time. The attention mechanism is taken into account for the feature extraction stage in the proposed SSL model, which can focus on the most important information on the input features. We use the signals collected by microphone array to explore the performance of the model under different features, and find the most suitable input features of the proposed method. We compare our method with other models on public dataset. Experience results show a quite substantial improvement of sound source localizing performance.

The hydrogen evolution reaction (HER) of molybdenum disulfide (MoS2) is limited in alkaline and acid solution because the active sites are on the finite edge with extended basal plane remaining inert. Herein, we activated the interfacial S sites by coupling with Ru nanoparticles on the inert basal plane of MoS2 nanosheets. The density functional theory (DFT) calculation and experimental results show that the interfacial S electronic structure was modulated. And the results of ΔGH* demonstrate that the adsorption of H on the MoS2 was also optimized. With the advantage of interfacial S sites activation, the Ru-MoS2 needs only overpotential of 110 and 98 mV to achieve 10 mA·cm−2 in both 0.5 M H2SO4 and 1 M KOH solution, respectively. This strategy paves a new way for activating the basal plane of other transition metal sulfide electrocatalysts for improving the HER performance.

The ordered Pt-based intermetallic nanoparticles (NPs) with small size show superior magnetic or catalytic properties, but the synthesis of these NPs still remains a great challenge due to the requirement of high temperature annealing for the formation of the ordered phase, which usually leads to sintering of the NPs. Here, we report a simple approach to directly synthesize monodisperse ordered L10-FePt NPs with average size 10.7 nm without further annealing or doping the third metal atoms, in which hexadecyltrimethylammonium chloride (CTAC) was found to be the key inducing agent for the thermodynamic growth of the Fe and Pt atoms into the ordered intermetallic structure in the synthetic process. In particular, 10.7 nm L10-FePt NPs synthesized by the proper amount of CTAC show a coercivity of 3.15 kOe and saturation magnetization of 45 emu/g at room temperature. The current CTAC-assisted synthetic strategy makes it possible to deeply understand the formation of the ordered Pt-based intermetallic NP in solution phase synthesis.

M-type strontium ferrite is a kind of magnetic functional material with wide application prospect. In this work, SrFe12−xAlxO19 (0 ≤ x ≤ 1) and Sr1−yCayFe8Al4O19 (0 ≤ y ≤ 0.4) have been prepared by a hydrothermal method, and the effects of Al3+ doping and Al3+ and Ca2+ co-doping on the magnetic properties have been investigated. X-ray diffraction analysis indicates all the samples are a hexagonal structure, and the shift of the diffraction peaks suggests that Al3+ and Ca2+ are successfully doped in SrFe12O19. Field emission scanning electron microscope images show the particles have the hexagonal shape with the size of 1.1–2.9 µm. Vibrating sample magnetometer reveals that the doping of Al3+ and the co-doping Al3+ and Ca2+ can enhance magnetic properties of strontium ferrite. For example, the values of coercivity and the saturation magnetization of SrFe8Al4O19 are 914.1 Oe and 44.0 emu/g, which are 3% and 117% enhancement compared with SrFe12O19, respectively. For Sr1−yCayFe8Al4O19, coercivity and saturation magnetization increase from 914.1 Oe and 41.8 emu/g to 1047.2 Oe and 50.2 emu/g when the Ca2+ doping concentration increases from 0 to 0.4. Moreover, the effects of acid washing also on phase composition, morphology and magnetism are researched. The as-synthesized doping strontium ferrite will be useful for the applications in security switching and recording media.

The morphology and size of Pt-based bimetallic alloys are known to determine their electrocatalytic performance in reactions relevant to fuel cells. Here, we report a general approach for preparing Pt-M (M = Fe, Co and Ni) bimetallic nano-branched structure (NBs) by a simple high temperature solution-phase synthesis. As-prepared Pt-M NBs show a polycrystalline structure and are rich in steps and kinks on the surface, which promote them favorable bifunctional catalytic properties in acidic electrolytes, specifically in terms of the oxygen reduction reaction (ORR) and methanol oxidation reaction (MOR). Specially, Pt-Co NBs/C catalyst shows 6.1 and 5.3 times higher in specific activity (SA) and mass activity (MA) for ORR than state-of-the-art commercial Pt/C catalysts, respectively. Moreover, it exhibits a loss of 4.0% in SA and 14.4% in MA after 10,000 cycles of accelerated durability tests (ADTs) compared with the initial activities. In addition, we also confirmed the superior MOR activity of Pt-Co NBs/C catalyst in acidic electrolytes. For Pt-M NBs with other alloying metals, the ORR and MOR activities are both higher than commercial catalysts and are in the sequence of Pt-Co/C > Pt-Fe/C > Pt-Ni/C > commercial Pt/C (or PtRu/C). The improved activities and durability can benefit from the morphological and compositional effects. This synthesis approach may be applied to develop bifunctional catalysts with enhanced ORR and MOR properties for future fuel cells designs.

Developing low-cost and earth-abundant electrocatalysts with high performance for electrochemical water splitting is a challenging issue. Herein, we report a facile and effective way to fabricate three-dimension (3D) ordered mesoporous Co1− x Fe x P ( x =0, 0.25, 0.5, 0.75) electrocatalyst. Benefiting from 3D ordered mesoporous pore channels and composition optimization, the Co0.75Fe0.25P exhibits excellent electrocatalytic activities with low overpotentials of 270 and 209 mV at 10 mA cm−2 for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER), respectively, in the alkaline electrolyte along with a durable electrochemical stability. In addition, as both the cathode and anode, the Co0.75Fe0.25P also exhibits superior electrolysis water splitting performance with only an applied voltage of 1.63 V to attain a current density of 10 mA cm−2 without obvious decay for 18 h, indicating that the Co0.75Fe0.25P is an efficient electrocatalyst for overall water splitting.

In this paper, hierarchical mesoporous Co3O4@ZnCo2O4 hybrid nanowire arrays (NWAs) on Ni foam were prepared through a two-step hydrothermal process associated with successive annealing treatment. The Co3O4@ZnCo2O4 hybrid NWAs exhibited excellent electrochemical performances with a high specific capacity of 1,240.5 C g−1 at a current density of 2 mA cm−2, with rate capability of 59.0% shifting from 2 to 30 mA cm−2, and only a 9.1% loss of its capacity even after 3,000 cycles at a consistent current density of 10 mA cm−2. An asymmetric supercapacitor (Co3O4@ZnCo2O4 NWAs||activated carbon) was fabricated and exhibited a high specific capacity of 168 C g−1 at a current density of 1 A g−1. And a preferable energy density of 37.3 W h kg−1 at a power density of 800 W kg−1 was obtained. The excellent electrochemical performances indicate the promising potential application of the hierarchical mesoporous Co3O4@ZnCo2O4 hybrid NWAs in energy storage field.

L10-FePt/[Fe/Pt]27 multilayer films were prepared on (100)-oriented single-crystal MgO substrates. Structural analysis indicates epitaxial growth of the L10-FePt films during high-temperature deposition. The room-temperature-deposited [Fe/Pt]27 multilayer exhibits the fcc-FePt structure grown epitaxially on the L10-FePt base layer. The degree of chemical order and thereby the anisotropy of the top layer has been controlled by varying the temperature of a post-deposition annealing process. Compared with the as-deposited films, coercivities of the films annealed below 400 ∘C are substantially decreased by introducing the formation of a graded anisotropy in the partially ordered top layer. Coercivities decrease for annealing temperatures that are greater than 400 ∘C due to improved ordering of the top layer.

Author name disambiguation is an important problem that needs to be resolved in bibliometric analysis or tech mining. Many techniques have been presented; however, most of them require a long run time or additional information. A new method based on semantic fingerprints was presented to disambiguate author names without external data. A manually annotated dataset was built to testify on the efficiency of the presented method. Experiments using co-author features, institution features, and text fingerprints were conducted respectively. We found that the first two methods had higher precision, but their recall was low, and the text fingerprint method had higher recall and satisfied precision. Based on these results, we integrated co-author features, institution features, and text fingerprints to provide semantic fingerprints for disambiguating author names and achieving better performance on the F-measure.

Specific and dynamic biological interactions pave the blueprint of signal networks in cell. For example, a great variety of specific protein-ligand interactions define how intracellular signals flow. Taking advantage of the specificity of these interactions, we postulate an “affinity-guided covalent conjugation” strategy to lock binding ligands through covalent reactions between the ligand and the receptor protein. The presence of a nucleophile close to the ligand binding site of a protein is sine qua none of this reaction. Specific noncovalent interaction of a ligand derivative (which contains an electrophile at a designed position) to the ligand binding site of the protein brings the electrophile to the close proximity of the nucleophile. Subsequently, a conjugation reaction spontaneously takes place between the nucleophile and the electrophile, and leads to an intermolecular covalent linkage. This strategy was first showcased in coiled coil peptides which include a cysteine mutation at a selected position. The short peptide sequence was used for covalent labeling of cell surface receptors. The same strategy was then used to guide the design of a set of protein Lego bricks for covalent assembly of protein complexes of unnatural geometry. We finally made “reactive peptides” for natural adaptor proteins that play significant roles in signal transduction. The peptides were designed to react with a single domain of the multidomain adaptor protein, delivered into the cytosol of neurons, and re-directed the intracellular signal of neuronal migration. The trilogy of protein labeling, assembly, and inhibition of intracellular signals, all through a specific covalent bond, fully demonstrated the generality and versatility of “affinity-guided covalent conjugation” in various applications.

Covariance tracking has achieved impressive successes in recent years due to its competent region covariance-based feature descriptor. Although adopt fast integral image computation, covariance tracking's brute-force search strategy is still inefficient and it possibly leads to inconsecutive tracking trajectory and distraction. In this work, a generalized, adaptive covariance tracking approach with novel integral region computation and occlusion detection is proposed. The integral region is much faster than integral image and adaptive to the tracking target and tracking condition. The adaptive search window can be adjusted dynamically by simple occlusion detection. The integral image and the global covariance tracking can be seen just a special case of integral region and the proposed approach, respectively. The proposed approach unifies the local and global search strategies in an elegant way and smoothly switches between them according to the tracking conditions (i.e. occlusion distraction or sudden motion) which are judged by occlusion detector. It gets much better efficiency, robustness of distraction, and stable trajectory by local search in normal steady state, while obtains more abilities for occlusion and re-identification by enlarged search window (until to global search) in abnormal situation at the same time. Our approach shows excellent target representation ability, faster speed, and more robustness, which has been verified on some video sequences.

There is a growing need for confidential institutions to actively check the documents in Internet for detecting some leaked confidential images. This paper presents an efficient method of active image betrayal checking based on a new type of watermarking in addition to the user-specific fingerprint. The implemented organization's watermarking, as a `fingerprint' for a group of staffs, with a codeword length far shorter than that of the user-specific fingerprint, is extracted from a suspected image at the first stage of betrayal checking, for the purpose of reducing the number of suspected images by a great deal. Then, only the remaining suspected images are subjected to the time-consuming user-specific fingerprint checking. Experimental tests confirmed the improved efficiency of this method.

FePt/Ag films were deposited on thermally oxidized Si(100) substrates by magnetron sputtering at room temperature and then the as-deposited films were annealed at 500 ∘C. The microstructure and magnetic properties of the films have been investigated by X-ray diffraction and vibrating sample magnetometry. The results indicate that introduction of the Ag underlayer promotes an ordering transformation of the FePt phase due to thermal tensile stress between the Ag underlayer and the FePt film. The in-plane tensile stress induced by the Ag underlayer should stretch the horizontal lattice parameter of FePt; thus, it is helpful for the ordering transformation. With increasing Ag underlayer thickness, the ordering parameter and coercivity first increase and then decrease. When the Ag underlayer thickness is 12 nm, the ordering parameter and coercivity of the film reach the maximum values, respectively. The Ag underlayer thickness also affects the magnetization reversal mechanism.

FeAg and FeAg/Pt films were prepared by dc magnetron sputtering at room temperature. The effects of Ag volume fraction in FeAg films and postannealing temperature and time on structure and magnetic properties of FeAg and FeAg/Pt films have been investigated. The results show that the as-deposited FeAg films are metastable. After annealing at 300°C, the phase separation of metastable FeAg films happened and the highest coercivity is obtained in Fe50Ag50/Pt film. With increasing annealing temperature, the ordering and the magnetic properties of the Fe50Ag50/Pt films were improved. When the Fe50Ag50/Pt films are annealed at 600°C for different annealing times, a long annealing time enhances the ordering of the metastable Fe50Ag50/Pt films and affects the orientation development. When the films are annealed for a long time, the grain size and the magnetic domain size also increase, which lead to an increase of correlation length due to the growth of FePt grains.

How protein–protein interaction affects protein–nanoparticle self-assembly is the key to the understanding of biomolecular coating of nanoparticle in biological fluids. However, the relationship between protein shape and its interaction with nanoparticles is still under-exploited because of lack of a well-conceived binding system and a method to detect the subtle change in the protein–nanoparticle assemblies. Noticing this unresolved need, we cloned and expressed a His-tagged SpeA protein that adopts a bridge-shaped dimer structure, and utilized a high-resolution capillary electrophoresis method to monitor assembly formation between the protein and quantum dots (QDs, 5 nm in diameter). We observed that the bridge-shaped structure rendered a low SpeA:QD stoichiometry at saturation. Also, close monitoring of imidazole (Im) displacement of surface-bound protein revealed a unique two-step process. High-concentration Im could displace surface-bound SpeA protein and form a transient QD–protein intermediate, through a kinetically controlled displacement process. An affinity-driven equilibrium step then followed, resulting in re-assembling of the QD–protein complex in about 1 h. Through a temporarily formed intermediate, Im causes a rearrangement of His-tagged proteins on the surface. Thus, our work showcases that the synergistic interplay between QD–His-tag interaction and protein–protein interaction can result in unique properties of protein–nanoparticle assembly for the first time.