Surface characterization, mechanical properties and corrosion behaviour of ternary based ZneZnOeSiO2composite coating of mild steel

Zinc coatings are obtained either from cyanide, non-cyanide alkaline or acid solutions. Because of the pollution and high cost associated with cyanide, deposition from other baths is gaining importance. In order to develop a bath with additive that could produce a quality coating is the motivation behind this present work which is surface modification of Zne8ZnOeSiO2 nano composite coating on mild steel surface by electrodeposition route. The influence of SiO2 on Zne8ZnO sulphate electrolyte on the properties and microstructure of the produced nano-coatings were investigated. The SiO2 was varied from 0 to 16wt%. The microstructure characteristics of these produced series composites coating were investigated using scanning electron microscopy couple with energy dispersive spectroscopy (SEM/EDS), X-ray diffraction and atomic force microscopy (AFM). The corrosion degradation properties in 3.65% NaCl medium were studied using potentiodynamic polarization technique and characterized by high resolution optical microscope (HR-OPM). The hardness and wear of the composite coating were measured with high diamond microhardness tester and dry abrasive MTR-300 testers respectively. The results showed that average hardness value of 142.5 and 251.2HV and corrosion rate of 0.13088 and 0.00122 mm/yr were obtained for the 0 and 16wt% SiO2 in Zne8ZnO. The work have established that upto 16% SiO2 in Zne8ZnO composite coating on mild steel can be used in improving the microhardness, wear loss and corrosion resistance of mild stee

IrMo Nanocluster-Doped Porous Carbon Electrocatalysts Derived from Cucurbit[6]uril Boost Efficient Alkaline Hydrogen Evolution

Electrocatalysts based on noble metals have been proven efficient for high-purity hydrogen production. However, the sluggish kinetics of the hydrogen evolution reaction (HER) in alkaline media caused by high water dissociation energy largely hampers this electrochemical process. To improve the electrocatalytic activity, we fabricate an effective porous carbon matrix derived from cucurbit[6]uril using a template-free method to support iridium–molybdenum (IrMo) nanoclusters. As proof of concept, the resulting IrMo-doped carbon electrocatalyst (IrMo-CBC) was found to boost the alkaline HER significantly. Owing to the unique in-plane hole structure and the nitrogen-rich backbone of cucurbit[6]uril as well as the ultrafine IrMo nanoclusters, IrMo-CBC exhibits pronounced alkaline HER activity with an extremely low overpotential of 12 mV at 10 mA cm–2, an ultrasmall Tafel slope (28.06 mV dec–1), a superior faradic efficiency (98%), and a TOF of 11.6 H2 s–1 at an overpotential of 50 mV, outperforming most iridium-based electrocatalysts and commercial Pt/C

A new phenolic glycoside and two new monoterpenoid furocoumarins from Aurantii Fructus Immaturus

<p>A new phenolic glycoside, citrauranoside A (<b>1</b>), and two new monoterpenoid furocoumarins, citraurancoumarin A (<b>2</b>) and citraurancoumarin B (<b>3</b>), along with four known compounds (<b>4–7</b>) were isolated from the young fruit of <i>Citrus aurantium</i> L. The structures were elucidated by their comprehensive analysis including 1D, 2DNMR, IR and mass spectra.</p

Different responses of AI neurons at varied intervals between paired stimuli.

<p><b>A</b>) Five superimposed waveforms of the paired sound-evoked responses in AI neurons after train stimulation of the MGBv at incremental intervals between the paired stimuli. <b>B</b>) The statistical broken line chart of the average amplitude of the EPSPs in (A). When the frequency of the train stimuli was 10 Hz, the amplitudes of the sound-evoked EPSPs significantly increased immediately after the train stimulation of the MGBv (compared with the control level), and then decreased to a level lower than the control group when the stimulus interval was extended to 700 ms. Finally, when the stimulus interval was approximately 800 ms, it reached the average amplitude of sound-evoked EPSPs without train stimulation (that is, the level of the control group). In contrast, the 100 Hz train electrical stimulation of the MGBv at first decreased the amplitudes of sound-evoked EPSPs in AI neurons to a significant low level. The amplitudes of the EPSPs then increased to the level of control group. The amplitudes of the EPSPs in both the high- and low-frequency group reached the control level and stabilized at the plateau when the stimulus interval was longer than 800 ms. (*<i>P</i><0.05, **<i>P</i><0.01).</p

Different responses of AI neurons at varied frequencies and intervals of train stimuli.

<p><b>A</b>) Five superimposed traces of the sound-evoked responses in AI neurons after train stimulation of the MGBv at incremental frequencies of electrical stimulation and intervals between the paired stimuli. <b>B</b>) The statistical broken line chart of the average amplitudes of the EPSPs in (A). When the stimulus intervals were shorter than 700 ms, the changing tendencies of the different groups of varied stimulus intervals were approximately the same. They all exhibited consistent effects. The amplitudes of the sound-evoked EPSPs of AI neurons increased to higher than those of the control group when the train stimulus frequency of the MGBv was 10 Hz. When the frequencies of the electrical stimuli increased to high levels, including 50 Hz, 100 Hz and 150 Hz, the amplitudes of the EPSPs all decreased to lower than those of the control group. In particular, when the frequency was 50 Hz, the amplitudes of the EPSPs were significantly lower than those of the control group, and might even be close to zero. (*<i>P</i><0.05).</p

Greedy algorithm procedure.

<p>Greedy algorithm procedure.</p

Comparison of different repair schedules.

<p>Comparison of different repair schedules.</p

Confirmation of the location of the MGBv.

<p><b>A</b>) The receptive field of the recorded MGBv neurons. This field had a typical “V" shape that was in concordance with the representative receptive field of the neurons in the MGBv, which further confirmed the location of the MGBv. The best frequency of this single unit was approximately 13 kHz, and its minimum threshold was approximately 7 dB SPL. <b>B</b>) The anatomical location of the site of electrical stimulation. A micrograph of the coronal section of the right brain compared with the atlas at 5.5 mm posterior to the bregma. A lesion site enwrapped with a thick layer of injured neurons could be observed at the corresponding position of the MGBv according to the atlas, whose boundary was sleek and clear-cut. Inset, position of the section in the rat brain. CTX, cortex; MGBv, ventral portion of the medial geniculate body; Hip, hippocampus; CA1, CA2, CA3, fields CA1, CA2, and CA3 of the hippocampus; SNR, reticular part of the substantia nigra; SC, superior colliculus; DpG, deep gray layer of the superior colliculus.</p

Unusual Protonation of the Hydroxylammonium Cation Leading to the Low Thermal Stability of Hydroxylammonium-Based Salts

Energetic ionic salts (EISs) are a class of thriving and promising energetic materials (EMs) that can possess excellent properties and performances comparable to common conventional EMs composed of neutral molecules. As EMs, their response mechanisms to external stimuli are strongly responsible for their safety and thus are highly concerned about. Nevertheless, insight into these mechanisms remains still lacking. We find in the present work a bimolecular reaction between two same sign charged ions during heating dihydroxylammonium 5,5′-bistetrazole-1,1′-diolate (TKX-50), a typical EIS that are attracting increasing attention with a high potential of practical applications. That is, the protonation of NH₃OH⁺, or a reaction between two cations, occurs and serves as a dominant initial step in the thermal decay of TKX-50. This is a rare case as a bimolecular reaction can usually hardly take place between two ions with same sign charges (two anions or two cations), due to their electrostatic repulsion preventing their sufficient approaching each other to induce the reaction. The protonation proceeds by a H⁺ transfer from a NH₃OH⁺ to its neighboring one, and subsequently decompose NH₃OH⁺ to the final stable products of NH₃ and H₂O simultaneously to collapse the crystal lattice of TKX-50. This new finding can well explain the experimental observations of the prior decay of NH₃OH⁺ to the bistetrazole-1,1′-diolate anion when TKX-50 heated at a constant temperature of 190 °C and the relatively low thermal stability of NH₃OH⁺ based EISs relative to others. Thereby, we propose a strategy to avoid a ready proton transfer and subsequent decomposition to enhance the thermal stability of EISs. This work is hopefully to richen the insight into both the decay mechanism of EISs and the mechanism of the reactions between same sign charged ions

Rank of critical link under different road network states.

<p>Rank of critical link under different road network states.</p