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Intrinsic Au-decoration on anodic TiO2 nanotubes grown from metastable Ti–Au sputtered alloys—High density co-catalyst decoration enhances the photocatalytic H2 evolution
摘要： Recent work demonstrated that intrinsic Au nanoparticle decoration of TiO2 nanotube arrays (NTs) can be achieved by electrochemical anodization of Ti–Au alloy substrates. However, for a Ti–Au cast alloy produced by melt-alloying, the Au concentration cannot exceed the solubility limit of Au in Ti of 0.2 at.% – this sets constraints on the intrinsic Au nanoparticle loading on anodic TiO2 NTs. Here we explore “metastable” Ti–Au metal substrates that are produced by Ti and Au cosputtering and we establish Au concentrations that far exceed the solubility limit in cast Ti–Au alloys. We show the use of these “metastable” Ti–Au sputtered layers for the anodic formation of TiO2 NTs with a much higher density of Au nanoparticle loading than using classic alloys. Under optimized conditions (Au nanoparticle density) photocatalytic H2 production from such Au@TiO2 platforms provides a 15 times higher photocatalytic H2 evolution rate than the best rates achieved with conventional alloys.
关键词： Anodic TiO2 nanotube,Metastable Ti–Au alloy,Sputtering,Anodization,Photocatalytic H2 evolution
更新于2025-09-23 15:23:52
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Organic/inorganic nitride heterostructure for efficient photocatalytic oxygen evolution
摘要： Given the four-electron water oxidation reaction as the rate-limiting step for water splitting, highly efficient photocatalysts for oxygen evolution have been receiving increasing research attentions. In this study, an organic/inorganic g-C3N4/CoN nitride heterostructure was developed by a facile precipitation-nitridation two-step process. With the CoN loading amounts optimized, the obtained g-C3N4/CoN composite achieves more than 4-fold increase in photocatalytic activity for oxygen evolution, as compared to the pristine g-C3N4, with a highest oxygen evolution rate reaching 607.2 μmol h?1 g?1 under visible light (λ > 420 nm). It was demonstrated that the formed g-C3N4/CoN heterostructure could promote the interfacial charge carrier separation and the loaded CoN acting as an effective cocatalyst could accelerate the water oxidation reaction kinetics, which synergistically contributes to the great enhancement in photocatalytic activity for oxygen evolution. Interestingly, by physically mixing g-C3N4/CoN and g-C3N4/Ni, acting as oxygen and hydrogen production photocatalysts, respectively, the obtained composite could stably produce oxygen and hydrogen in the stoichiometric ratio from pure water under visible light (λ > 420 nm). Although the photocatalytic overall water splitting activity is still very low, this study demonstrates a facile and promising approach to develop visible-light active photocatalysts for simultaneous hydrogen and oxygen production from water, from the perspective of surface modification and bifunctional cocatalyst loading.
关键词： Oxygen evolution,g-C3N4,Photocatalytic water splitting,Heterostructures
更新于2025-09-23 15:23:52
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SDSS J122958.84+000138.0: A compact, optically red galaxy
摘要： We report a new compact galaxy, SDSS J122958.84+000138.0 (SDSS J1229+0001), which has unique morphological and stellar population properties that are rare in observations of the nearby Universe. SDSS J1229+0001 has an r-band absolute magnitude (Mr) and half-light radius (Rh) of ?17.75 mag and 520 pc, respectively. Located in a fairly low-density environment, morphologically it is akin to a typical early-type galaxy as it has a smooth appearance and red colour. However, interestingly, it possesses centrally concentrated star-forming activity with a significant amount of dust. We present an analysis of its structural and stellar population properties using archival images and VLT/FORS2 spectroscopy. An analysis of the UKIDSS H-band image shows that the observed light distribution is better fitted with a two-component Sérsic function with inner and outer component effective radii of 190 and 330 pc, respectively. The overall half-light radius measured in the H band is much smaller compared to optical, i.e. 290 pc. We prepared a spectral energy distribution from optical to far-infrared and interpret it to derive the star-formation rate, dust mass and stellar mass. We find that SDSS J1229+0001 has dust mass Mdust = 5.1 × 10^5 M☉ with a dust-to-stellar mass ratio log(Mdust/M?) = ?3.5. While the observed stellar population properties are – to some extent – like those of a typical S0 galaxy, a unified view from stellar population and structural properties may suggest that SDSS J1229+0001 is a smoking gun example of a compact early-type galaxy in formation.
关键词： galaxies: formation,galaxies: star formation,galaxies: elliptical and lenticular, cD,galaxies: individual: SDSS J122958.84+000138.0,galaxies: evolution,galaxies: dwarf
更新于2025-09-23 15:22:29
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The Herschel-PACS North Ecliptic Pole Survey
摘要： A detailed analysis of Herschel/Photoconductor Array Camera and Spectrometer (PACS) observations at the North Ecliptic Pole is presented. High-quality maps, covering an area of 0.44 deg2, are produced and then used to derive potential candidate source lists. A rigorous quality-control pipeline has been used to create ?nal legacy catalogues in the PACS Green 100 μm and Red 160 μm bands, containing 1384 and 630 sources respectively. These catalogues reach to more than twice the depth of the current archival Herschel/PACS Point Source Catalogue, detecting 400 and 270 more sources in the short- and long-wavelength bands, respectively. Galaxy source counts are constructed that extend down to ?ux densities of 6 mJy and 19 mJy (50% completeness) in the Green 100 μm and Red 160 μm bands, respectively. These source counts are consistent with previously published PACS number counts in other ?elds across the sky. The source counts are then compared with a galaxy evolution model which identi?es a population of luminous infrared galaxies as responsible for the bulk of the galaxy evolution over the ?ux range (5–100 mJy) spanned by the observed counts, contributing approximate fractions of 50% and 60% to the cosmic infrared background at 100 μm and 160 μm, respectively.
关键词： galaxies: evolution,surveys
更新于2025-09-23 15:22:29
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Fabrication of new metal-free materials for the hydrogen evolution reaction on base of the acridine derivatives immobilized on carbon materials
摘要： The process of adsorption on carbon material (Vulcan XC-72 (VU)) of organic heterocyclic compounds: acridine (I) and its derivatives 9-phenylacridine (II) and N-methyl-9-phenylacridium iodide (III) was studied in detail. Quantitative data on physical adsorption were obtained for all compounds. Based on the adsorption isotherms of Langmuir, the adsorption equilibrium constants K, the parameter A∞ and ΔG0 ad were calculated. It has been shown that the adsorption of compounds I and II is a structurally dependent process that depends on the nature and size of the functional substituents in the molecule, and the adsorption of compound III has a complex mechanism and partially proceeds through the stabilization stage by the functional groups present on the surface (-COOH, -COH, -OH). With the use of quantum chemical calculations, it has been established that the process of adsorption of compounds on the surface of a carbon materials having sections with a graphite-like structure is thermodynamically unprofitable because of the high difference in the energies of the adsorbent's boundary orbitals and the substrate. Using the cyclic voltammetry method, the electrochemical properties of organic compounds immobilized on the surface of a carbon material were studied.
关键词： Electocatalysis,Acridine derivatives,Immobilization,Adsorption,Carbon materials,Hydrogen evolution reaction
更新于2025-09-23 15:22:29
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[IEEE 2018 IEEE 3rd International Conference on Image, Vision and Computing (ICIVC) - Chongqing (2018.6.27-2018.6.29)] 2018 IEEE 3rd International Conference on Image, Vision and Computing (ICIVC) - Improved Differential Evolution with Parameter Adaption Based on Population Diversity
摘要： The differential evolution algorithm is an important branch of the bionic intelligent computation, which uses the Darwinian population's evolutionary principle: survival of the fittest and survival of the fittest. Due to the simple implement and few parameters, many researchers have invested into the study of the algorithm and proposed a large number of differential evolution variants. For the existing differential evolution algorithm, once the size of the population is determined, the size of the search range is fixed. Based on the global diversity of population, we focus on controlling the value of the search parameters p. In the proposal, after normalizing the population diversity, each individual will select its unique search scope according to the diversity conditions. Therefore, the proposed method can balance between the global search and the local search. According to our extensive experimental results on various benchmark functions, the proposed method outperform other compared advanced algorithms.
关键词： population diversity,SHADE,differential evolution
更新于2025-09-23 15:22:29
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[ASME ASME 2018 International Technical Conference and Exhibition on Packaging and Integration of Electronic and Photonic Microsystems - San Francisco, California, USA (Monday 27 August 2018)] ASME 2018 International Technical Conference and Exhibition on Packaging and Integration of Electronic and Photonic Microsystems - Microstructural Evolution in SAC305 and SAC-Bi Solders Subjected to Mechanical Cycling
摘要： Fatigue failure of solder joints is one of the most common methods by which electronic packages fail. Electronic assemblies usually must cope with a temperature varying environment. Due to the mismatches in coefficients of thermal expansion (CTEs) of the various assembly materials, the solder joints are subjected to cyclic thermal-mechanical loading during temperature cycling. The main focus of this work is to investigate the changes in microstructure that occur in SAC305 and SAC+Bi lead free solders subjected to mechanical cycling. In this paper, we report on results for the SAC+Bi solder commonly known as SAC_Q or CYCLOMAX. Uniaxial solder specimens were prepared in glass tubes, and the outside surfaces were polished. A nanoindenter was then used to mark fixed regions on the samples for subsequent microscopy evaluation. The samples were subjected to mechanical cycling, and the microstructures of the selected fixed regions were recorded after various durations of cycling using Scanning Electron Microscopy (SEM). Using the recorded images, it was observed that the cycling induced damage consisted primarily of small intergranular cracks forming along the subgrain boundaries within dendrites. These cracks continued to grow as the cycling continued, resulting in a weakening of the dendrite structure, and eventually to the formation of large transgranular cracks. The distribution and size of the intermetallic particles in the inter-dendritic regions were observed to remain essentially unchanged.
关键词： Bismuth,Microstructure,SAC Alloy,Hysteresis,Evolution,Lead Free Solder,Cyclic Stress-Strain Curve
更新于2025-09-23 15:22:29
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Network Structured CuWO4/BiVO4/Co-Pi Nanocomposite for Solar Water Splitting
摘要： A network structured CuWO4/BiVO4 nanocomposite with a high specific surface area was prepared from CuWO4 nanoflake (NF) arrays via a method that combined drop-casting and thermal annealing. The obtained CuWO4/BiVO4 exhibited high catalytic activity toward photoelectrochemical (PEC) water oxidation. When cobalt phosphate (Co-Pi) was coupled with CuWO4/BiVO4, the activity of the resulting CuWO4/BiVO4/Co-Pi composite for the oxygen evolution reaction (OER) was further improved. The photocurrent density (Jph) for OER on CuWO4/BiVO4/Co-Pi is among the highest reported on a CuWO4-based photoanode in a neutral solution. The high activity for the PEC OER was attributed to the high specific surface area of the composite, the formation of a CuWO4/BiVO4 heterojunction that accelerated electron–hole separation, and the coupling of the Co-Pi co-catalyst with CuWO4/BiVO4, which improved the charge transfer rate across composite/solution interface.
关键词： copper tungstate,cobalt phosphate,oxygen evolution reaction,bismuth vanadate,photoelectrochemical water splitting
更新于2025-09-23 15:22:29
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Absolute parameters for AI Phoenicis using WASP photometry <i>(Corrigendum)</i>
摘要： An error has been noted in the linear ephemeris for AI Phe, shown in Eq. (2) of the paper. The correct ephemeris is This is typographical error and has no effect on any of the timing analysis presented in the paper. HJD Pri. Min. = 2 455 805.24370(21) + 24.592483(17) E.
关键词： stars: fundamental parameters,errata,binaries: eclipsing,stars: evolution,addenda,stars: solar-type
更新于2025-09-23 15:22:29
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In-situ Platinum Plasmon Resonance Effect Prompt Titanium Dioxide Nanocube Photocatalytic Hydrogen Evolution
摘要： In-situ photodeposition Pt nanoparticles (Pt NPs) on TiO2 on account of the surface plasmonic resonance (SPR) effect and strong interaction of two components, which exhibits an elevated solar-driven photocatalytic hydrogen evolution performance. Herein, Pt-decorated TiO2 nanocube hierarchy structure (Pt-TNCB) was in-situ fabricated via a facile solvothermal synthesis and photodeposition strategy. The Pt-TNCB exhibits an excellent solar-driven photocatalytic hydrogen evolution rate (337.84 μmol h-1), which is about 37 times higher than that of TNCB (9.19 μmol h-1). Interestingly, its photocatalytic property is still superior to TNCB with post modification Pt (1 wt %) (208.11 μmol h-1). The introduction of Pt efficiently extends the photoresponse of composite material from UV to visible light region, simultaneously boost their solar-driven photocatalytic performance, which attribute to the porous structure, the subsize TNCB, the SPR effect of Pt NPs and strong interaction of two components. In fact, Pt NPs can enhance collective oscillations on delocalized electrons, which is conducive to capture electrons and hinder the recombination of photogenerated electron-hole pairs, leading to the longer lifetime of photogenerated charges. The fabrication of Pt-TNCB photocatalyst with SPR effect may provide a promising method to improve visible-light photocatalytic activities for traditional photocatalysts.
关键词： hydrogen evolution,titanium dioxide,surface plasmonic resonance,photodeposition,photocatalyst
更新于2025-09-23 15:22:29