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Highly active Keggin-type silicotungstic acid (SiW12) with oxygen vacancy (Ov) defects was encapsulated into the magnetic floral N-doped carbon microspheres (γ-Fe2O3@NC-300) through the facile one-step air pyrolysis of the precursor comprising core–shell Fe3O4@polydopamine (Fe3O4@PDA) and SiW12 to prepare γ-Fe2O3@NC@SiW12-300. The fabricated catalysts were systematically characterized and subsequently employed for the oxidation desulfurization (ODS) of the model fuel. The magnetic floral γ-Fe2O3@NC@SiW12-300 catalyst exhibited nearly perfect catalytic activity, which under mild conditions could remove 100% amount of 4000 ppm DBT in model fuel within 20 min (0.03 g catalysts and n(H2O2)/n(S) of 2). The catalyst activity is mainly attributed to the high activity SiW12 with the Ov defect and its outstanding dispersibility in γ-Fe2O3@NC, along with the high number of exposed active sites. A selected catalyst, γ-Fe2O3@NC@SiW12-300, showed a noticeable turnover frequency (TOF) (110.07 h−1) and lower activation energy (38.79 kJ mol−1) in oxidative desulfurization (ODS) with good recyclability. HO˙ radical was found to be the active species involved in ODS as confirmed by the EPR and scavenger experiments. Additionally, the fabricated catalyst can be conveniently separated and recycled within an externally applied magnetic field. [ABSTRACT FROM AUTHOR]

In this study, the synthesis of Co/Al hydrotalcite (layered double hydroxides: LDHs) using insoluble Al[(OH).sub.3] by a hydrothermal method is described. The syntheses were conducted under various conditions. The as-prepared Co/Al-C[O.sub.3.sup.2-]-LDH was characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The tribological properties of the products were evaluated in base oil using four-ball and Plint friction testers. The LDH thus synthesized displays perfect hexagonal platelike morphology having a disk diameter in the range of 0.2-1.5 µm with a thickness of 40 nm. The addition of the product Co/Al-C[O.sub.3.sup.2-]-LDH, as an additive to the base oil, significantly reduces the friction coefficient (22.3%) and wear (26.1%) compared to base oil alone. The morphology and chemistry of the worn surface were characterized by SEM, atomic force microscopy (AFM), and X-ray absorption near-edge structure (XANES) spectroscopy. The results show that the structural distortion of LDH induced by mechanochemical processes during friction consumes the friction force between the rubbed surfaces, and as a result, the friction and the wear is reduced. Thus, our results show that the LDH sheets absorbed on the worn surface can prevent direct contact between the friction pairs (surfaces) and decreases the roughness of the worn surface. Key words: Co/Al hydrotalcites, antifriction, tribochemistry, X-ray absorption near-edge structure (XANES). La presente etude decrit la synthese d'hydrotalcite de Co/Al (hydroxydes doubles lamellaires ou HDL) a l'aide d'Al[(OH).sub.3] insoluble par methode hydrothermale. Les syntheses ont ete realisees dans diverses conditions. Les Co/Al-C[O.sub.3.sup.2-]-HDL ainsi prepares ont ete caracterises par diffractometrie de rayons X (DRX) et microscopie electronique a balayage (MEB). Les proprietes tribologiques des produits ont ete etudiees dans de l'huile de base a l'aide de bancs d'essai de frottement a quatre billes et de tribometres Plint. Les HDL ainsi synthetises presentent une morphologie hexagonale parfaite en plaque dont le diametre de disque est compris entre 0,2 et 1,5 µm et l'epaisseur egale a 40 nm. L'ajout du produit Co/Al-C[O.sub.3.sup.2-]-HDL, comme additif a l'huile de base, reduit considerablement le coefficient de frottement (22,3%) et l'usure (26,1%), par rapport a l'huile de base seule. La morphologie et la chimie de la surface usee ont ete caracterisees par MEB, microscopie a force atomique (MFA) et spectroscopie de structure pres du front d'absorption de rayons X. Les resultats montrent que la distorsion structurale des HDL provoquee par les processus mecanochimiques ayant lieu lors des frottements reduit la force de frottement presente entre les surfaces enduites, ce qui entraine une diminution du frottement et de l'usure. Nos resultats demontrent ainsi que les feuilles d'HDL absorbees sur la surface usee peuvent empecher les paires de frottement (surface) d'etre en contact et reduisent la rugosite de la surface usee. [Traduit par la Redaction] Mots-cles: hydrotalcites de Co/Al, antifriction, tribochimie, spectroscopie de structure pres du front d'absorption de rayons X., Introduction Layered double hydroxides (LDHs) are a class of layered anionic clays having the general formula of [[M.sub.(1-x).sup.2+][M.sub.x.sup.3+][(OH).sub.2]][([A.sup.n-]).sub.x/n] x z[H.sub.2]O, where [M.sup.2+] (Mg, Mn, Fe, Co, Ni, Cu, Zn, etc.) [...]

The roles of various fillers, i.e. short carbon fibers (SCF), graphite, hexagonal structured tungsten disulfide (WS 2 ) and aluminium nitride (AlN) nanoparticles, on the tribologial performance of polyphenylene sulphid (PPS) were explored with low-sulfur diesel as lubricant. It was demonstrated that the nanoparticles, especially AlN, remarkably improved the tribologial performance of PPS composites under diesel lubrication conditions. Moreover, presence of only very limited quantity of diesel results in the best tribological performance. It was manifested that the tribological performance was closely dependent on the tribofilm formed on steel counterface. Tribo-chemical reactions of PPS with both the steel counterpart and AlN nanoparticles were identified, as deemed important for generation of a robust tribofilm. [ABSTRACT FROM AUTHOR]

Abstract: La(OH)3 nanoparticles and serpentine/La(OH)3 composite particles were synthesized via sol–gel method. The phase compositions, micro-morphology of the synthesized particles were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The tribological properties of different samples were tested and compared by the MM-10W Multi-functional friction abrasion tester and MHK-500 Ring-block wear testing machine. The TEM figure indicates that La(OH)3 nanoparticles are granular, the average size of the particles is 50nm. The SEM figure of the composite particles illustrates that La(OH)3 particles uniformly coat on the surface of serpentine particles. The results of the friction tests indicate that serpentine, La(OH)3 and serpentine/La(OH)3 composite particles all exhibit friction-reducing and anti-wear properties compared to the base oil. The oil containing the composite particles have the best friction-reducing, anti-wear and self-repairing properties. The friction coefficients are reduced by 24.63% and the diameters of friction spots are reduced by 41.88% compared to the base oil. The energy spectrum of tribosurface gives evidence of that the contact area of rubbing pair was repaired by composite particles during friction tests. [Copyright &y& Elsevier]

Cu(In,Ga)(S,Se)2 (CIGSSe) solar cells are one of the most promising thin film photovoltaics with a record efficiency of 23.6%. However, the biggest drawback to CIGSSe solar cells is their high material cost, partially resulting from relatively rare and expensive indium and gallium. Therefore, improving the utilization of indium and gallium and reducing their wastage can greatly lower the cost of CIGSSe thin film solar cells. Inkjet printing is a facile, cost‐effective, and low‐waste deposition technology, which is particularly suitable for low‐cost and large‐area fabrication of CIGSSe solar cells. Herein, a novel and green ionic liquid‐assisted ink to fabricate highly efficient CIGSSe solar cells is developed. The material utilization of inkjet printing can be remarkably improved compared to the conventional vacuum‐based deposition approach and spin‐coating solution approach. The CIGS printable ink is prepared by dissolving copper acetate, indium acetate, gallium nitrate, and thiourea into ethanol with the assistance of n‐butylammonium butyrate ionic liquid. Ionic liquid‐assisted CIGS ink has a nearly zero wetting angle and a tunable viscosity, which enable to deposit a flat and continuous CIGS thin film by an inkjet printing method. An encouraging power conversion efficiency of 15.22% has been achieved for inkjet‐printed CIGSSe solar cells. [ABSTRACT FROM AUTHOR]

Copyright of Environmental Science & Technology (10036504) is the property of Editorial Board of Environmental Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Natural Disasters is the property of Gai Kan Bian Wei Hui and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Ultra-high speed machining technology enables high efficiency, high precision and high integrity of machined surface. Previous researches of hybrid bearing rarely consider influences of solid particles in lubricant and ultra-high speed of hybrid bearing, which cannot be ignored under the high speed and micro-space conditions of ultra-high speed water-lubricated hybrid bearing. Considering the impact of solid particles in lubricant, turbulence and temperature viscosity effects of lubricant, the influences of particles on pressure distribution, loading capacity and the temperature rise of the lubricant film with four-step-cavity ultra-high speed water-lubricated hybrid bearing are presented in the paper. The results show that loading capacity of the hybrid bearing can be affected by changing the viscosity of the lubricant, and large particles can improve the bearing loading capacity higher. The impact of water film temperature rise produced by solid particles in lubricant is related with particle diameter and minimum film thickness. Compared with the soft particles, hard particles cause the more increasing of water film temperature rise and loading capacity. When the speed of hybrid bearing increases, the impact of solid particles on hybrid bearing becomes increasingly apparent, especially for ultra-high speed water-lubricated hybrid bearing. This research presents influences of solid particles on the loading capacity and the temperature rise of water film in ultra-high speed hybrid bearings, the research conclusions provide a new method to evaluate the influence of solid particles in lubricant of ultra-high speed water-lubricated hybrid bearing, which is important to performance calculation of ultra-high speed hybrid bearings, design of filtration system, and safe operation of ultra-high speed hybrid bearings. [ABSTRACT FROM AUTHOR]