Search

In this paper, Bi2212 films were prepared on LaAlO 3 (100) and SrTiO 3 (100) substrates by the sol-gel method using Bi(NO 3) 3 ·5H 2 O, Sr(NO 3) 2 , Ca(NO 3) 2 ·4H 2 O and Cu(NO 3) 2 ·3H 2 O as raw materials. TritonX-100 (TX-100), fatty alcohol poly oxyethylene ether (AEO-9), poly (vinylpyrrolidone) (PVP) and poly (vinyl alcohol) (PVA) were used as surfactants, respectively, to improve the wettability between the sol and the substrate. When glycine and glycolic acid were used as complexing agents, these surfactants were stably miscible with the sols. The effects of different surfactant sol-gel systems on the wettability of substrates as well as the crystallinity, morphology, surface roughness and electrical transport properties of Bi2212 superconducting films were investigated. The results showed that flat and continuous c -axis epitaxial Bi2212 films were obtained using all these sol-gel systems. In particular, TX-100 and AEO-9 as surfactants showed stronger wettability of the sol-gel for both substrates. In addition, the films prepared using polymer surfactants PVP and PVA sol-gel systems showed less surface roughness. The same patterns were found in all the film samples prepared using precursor sols of different complexing agents, and all the films exhibited good electrical transport properties. This work lays a certain research foundation for the preparation of thin films by aqueous solvent sol-gel method. The method also shows great potential in terms of the stability of different sol-gel systems and the improvement of the wettability of different substrates. [ABSTRACT FROM AUTHOR]

The complexed sol-gel method has unique advantages in the preparation of multi-component functional thin films. In this paper, Bi2212 superconducting thin films were prepared by sol-gel method on SrTiO 3 (100) single crystal substrates. Glycine and glycolic acid were used as complexing agents. The thermal decomposition processes of the two sols were analyzed by contrasting thermal-thermogravimetric curves. The heat treatment processes of the different complexing agent systems were optimized to obtain films with flatter surface morphology. The phase composition of the intermediate products during the precursor heat treatment was changed by adjusting the conditions of the complexing agent and the acidity of the sol, which expanded the pure phase temperature interval of the final product. The pure phase temperature interval, morphology, surface roughness, and electrical transport properties of Bi2212 superconducting films prepared with different complexing agent sol-gel systems were investigated. When glycolic acid was used as the complexing agent, the Bi-2212 superconducting films showed the widest phase formation temperature zones of 25 K. They also had a smaller surface roughness of 10–15 nm. Other than that, all samples had good epitaxial properties, and electrical transport properties. This work provides a new idea for expanding the phase-forming temperature region of multicomponent functional ceramics. It also shows the promising potential of sol-gel method for preparing multicomponent functional films with high quality surfaces. [ABSTRACT FROM AUTHOR]

Lead-free ceramics have attracted considerable research attention owing to their environmentally friendly properties as well as their relatively good piezoelectric properties. Herein, we doped BiCoO 3 (BCO) onto (Bi 0.5 Na 0.5)TiO 3 –6BaTiO 3 (BNT-6BT) solid solution at various concentrations and investigated their dielectric and piezoelectric properties. After comparing the Rietveld refinement data with X-ray diffraction (XRD) results, it was found that all the BNT-6BT- x BCO ceramics (x = 0, 0.5%, 1%, and 1.5%) showed the morphotropic phase boundary conformation with coexisting tetragonal (P4bm) and cubic (Pm 3 (＿) m) phases. XRD refinement data also demonstrated that with increasing BCO concentration to 1.5%, the mole ratio between the tetragonal and cubic phases was close to 1:1, which enhanced the piezoelectric performance of the ceramic composites. At a BCO concentration of 1.5%, the strain and piezoelectric coefficient (d 33) of the sample reached 0.31% and 196 pC/N, respectively. The highest effective d 33 * of 489 pm/V was obtained at 110 °C with BNT-6BT-1.5BCO ceramics. The BNT-6BT-xBCO ceramics show great promise for use in high-temperature actuator applications. [ABSTRACT FROM AUTHOR]

[Display omitted] • Double-peak age strengthening phenomenon was first found in the Cu–Be–Ni–Co alloys. • The coherency strengthening of tiny nanoprecipitates contributes significantly to the appearance of first peak. • The light-mass Be atoms were directly made out by using the iDPC-STEM technology. Unconventional double-peak age strengthening phenomenon has occasionally been observed in some alloys, yet the underlying mechanism responsible for this phenomenon are still unclear. Here, we for the first time report the double-peak age strengthening phenomenon in the Cu–Be–Ni–Co alloys and try to unveil the underlying mechanism. Both the theoretical and experimental analyses demonstrate that the strong coherency strengthening effect of tiny nanoprecipitates (<1 nm) contributes significantly to the appearance of first peak, whereas the order-to-Orowan strengthening transformation accounts for the appearance of second peak. Moreover, the precipitate evolution processes of the alloys are identified as Guinier–Preston (GP) zones → γ′′→ γ′ and the light-mass Be atoms in the γ′ phase are directly made out by using integrated differential phase-contrast scanning transmission electron microscopy (iDPC-STEM) technology. Our work may provide new insights into the coherency strengthening effects and demonstrates a powerful strategy for designing high performance via double-peak behavior. [ABSTRACT FROM AUTHOR]

ZnO nanodevices have been widely used in practice, but one-dimensional ZnO grown in a polar preferred orientation is still partially localized. In this work, copper nitrate, nickel nitrate and silver nitrate were assisted with zinc acetate and hexamethylenetetetramine for the synthesis of ZnO films by conventional chemical bath deposition method. All samples were characterised by X-ray diffraction, field emission scanning electron microscopy, atomic force microscopy, photoluminescence, and UV–visible spectrophotometer. The results show that non-polar (110), (100) and coexisting preferred orientation ZnO films were controllably prepared by controlling the type and concentration of nitrate. On this basis, the growth process and mechanism of ZnO films with different nonpolar preferred orientations were characterized. It was also found that the ZnO films with 5 % Cu(NO 3) 2 ·3 H 2 O had the minimum surface roughness. The PL spectra confirmed the type and number of defects were also related to the preferred orientations. In addition, the non-polar (110) preferred orientation ZnO films had the highest optical transmittance of 82.26 %. This work enriches the method of preparing ZnO films with various nonpolar preferred orientations and provides new ideas for the design of ZnO-based transparent nanodevices. [Display omitted] • The defects and preferred orientation of ZnO film were effectively controlled by changing Cu, Ni and Ag ion concentrations. • Effective control of the preferred orientations of ZnO films. • Effective control of surface morphology and roughness by controlling cation type and concentration. • Analyzed the relationship between preferred orientations and internal defects of ZnO films. [ABSTRACT FROM AUTHOR]

Aqueous tape calendering offers the advantage of a simple fabrication process, inexpensive equipment, and environmental friendliness. Polyvinyl alcohol (PVA), as a polymer, is a conventional binder for aqueous tape calendering. In this innovative work, we aim to achieve a suitable process for tape calendering, by studying mechanical properties of the PVA polymer film with a series of plasticizers. The results show that the elongation at break of the PVA film reaches a maximum of 828.26%, using a triple plasticizer of glycerol, polyethylene glycol (PEG) 200, and PEG 400. With an optimized ratio of the binder to the plasticizer, a YSZ sheet with a relative density of 98% and a conductivity of 0.043 S cm−1 at 800 °C is obtained by sintering at 1400 °C, demonstrating comparable performance to those of the YSZ electrolytes by dry pressing. SEM reveals that the sintered YSZ body is dense, and has no visible open and closed pores. The mechanical properties characterization of the PVA polymer film adopted in this paper has instructive significant instruction for tape calendering and tape casting methods. • Mechanical properties measurement of the PVA film applied in an aqueous tape calendering. • The elongation at break of the PVA film reached 828%. • Combination of glycerol, PEG200 and PEG 400 plasticizer is a preferred choice for PVA binder. • The YSZ sheet sintered at 1400 °C has a density of more than 98% and a conductivity of 0.043 S cm−1 at 800 °C. [ABSTRACT FROM AUTHOR]

• A Fe ,N- doped graphene prepared by NH 3 plasma is reported. • The reduction of graphene oxide and Fe ,N- doping were achieved simultaneously after NH 3 plasma treatment. • The Fe ,N- doped graphene prepared by NH 3 plasma exhibits the high activity and durability for oxygen reduction reaction. • There is a large specific surface area and abundant pyridinic N of the sample treated by NH 3 plasma. To obtain a low cost and high performance non-noble metal catalysts and replace noble metal catalysts such as Pt-based catalysts in oxygen reduction reaction (ORR) are of a significant importance for sustainable energy conversion. A kind of Fe,N-doped graphene prepared by NH 3 plasma as a promising alternative was prepared. Various characterizations including XRD, TEM, XPS and BET were carried out. The results of XRD and XPS characterizations indicate that GO reduction and Fe ,N- doping were achieved simultaneously after NH 3 plasma treatment. There is a large amount of pyridinic N (up to 68.19% of the total nitrogen content) on the surface of Fe ,N- GO-P. Fe particle in Fe ,N- GO-P is so small that they cannot be found in the images of HRTEM. Compared with the Fe ,N- GO-C, Fe ,N- GO-P has a large specific surface area. Although the onset potential is negative, but it exhibits a high limiting current density and durability in alkaline medium. The mechanism of ORR on Fe ,N- GO-P has been revealed that is ,N- G a quasi-four electron reaction pathway Fe,N-GO-P mainly followed. [ABSTRACT FROM AUTHOR]

• A new general approach is proposed for solving 3D inverse heat conduction problems. • CVDM is introduced into ABAQUS for first time, to solve 3D inverse problems. • Newly developed complex variable FEM in ABAQUS with UEL is very accurate. • The approach is with good inversion performances. A novel general approach is proposed for solving three-dimensional transient nonlinear inverse heat conduction problems in irregular complex structures. The complex-variable-differentiation method (CVDM) is introduced into the commercial finite element method (FEM) software ABAQUS, for solving three-dimensional inverse heat conduction problems for the first time. First, the complex variable finite elements are set up, and the complex variable FEM is innovatively developed through the user element subroutine (UEL) in ABAQUS. Then, the key parameters in the Levenberg-Marquardt algorithm for solving inverse problems – sensitivity matrix coefficients – are accurately evaluated by utilizing the CVDM and ABAQUS standard solvers with the UEL. Finally, several numerical tests are carried out to verify the performances of the new approach for solving the three-dimensional transient nonlinear inverse heat conduction problem in an irregular complex structure. [ABSTRACT FROM AUTHOR]

In order to achieve flexible applications of superconducting thin film materials in devices, the surface quality of the film is critical. The thickness of the film is one of the important factors affecting its surface quality. In this paper, Bi2212 superconducting thin films of different thicknesses were prepared on LaAlO 3 (100) and SrTiO 3 (100) single crystal substrates by sol-gel method and the effects of film thickness and different heterogeneous structures on their crystallographic, morphological and superconducting properties were investigated. The results showed that the roughness gradually increased with increasing Bi2212 thickness at the initial stage of film growth and stabilized after reaching a certain thickness, while the superconducting properties were destroyed at very small sample thickness, which was consistent in both single-crystal substrate films. In the Bi2212/LaAlO 3 structure, the surface quality of the sample was excellent with a roughness of 5.4 nm at a thickness of about 18 nm for Bi2212, and the growth of the precipitated phase was inhibited to a greater extent. The film also had good superconductivity. This work provided a further research basis for the preparation of high quality Bi2212 films and offers further possibilities for their practical application. [Display omitted] • Preparation of epitaxially grown multi-component functional thin films-Bi2212 superconducting films. • Effective regulation of film thickness. • Effective improvement of the surface quality of the film by regulating the thickness of the film. • Modelling the variation process of the effect of film thickness on its surface quality. [ABSTRACT FROM AUTHOR]

Abstract Nine groups of wire arc additive manufacturing (WAAM) aluminum alloy walls with different layers were deposited by variable polarity cold metal transfer arc mode using ER 5183. Their microstructures were characterized by optical microscopy and electron back scattered diffraction. For the top layer, grain size increased from 37 μm to 65 μm, and then stabilized at around 41μm, in accordance with the decrease of microhardness from 98.7 HV to 76.4 HV. As the number of deposited layers increased, the anisotropy in the bottom layers was weaken, and small-angle grain boundary may cause an increment to 96.1HV in the microhardness before stabilized around 81HV due to the heat accumulation. [ABSTRACT FROM AUTHOR]

Abstract Nanotubes are easy to collapse due to van der Waals interactions and the low bending stiffness of their walls. The collapse may significantly alter the mechanical, thermal, and electronic properties of nanotubes, which can lead to many exciting applications of nanotubes in nanoelectronics and nanocomposites. In this paper, a theoretical model based on finite deformation beam theory is established to analyze the collapsing of single- and multi-wall nanotubes. Using this model, the critical diameters and the profile of collapsed nanotubes are predicted, which agree well with those obtained by molecular dynamics simulations. Furthermore, a simple scaling law of the critical collapse conditions of carbon nanotubes is built as a function of geometrical parameters, which can determine whether the carbon nanotube collapse. This scaling law can be easily extended to determine the collapsing state of other nanotube systems with different bending stiffness and binding energy. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • This is the first report of using a multifunctional antibacterial nanocomposite for both photocatalytic and photothermal sterilization. • The nanocomposite exhibited greatly enhanced broad-spectrum antibacterial activity compared with previous antimicrobials. • Biocompatibility experiments showed that our composites are safe therapeutic materials for the treatment of bacterial infections. Abstract Despite the development of various drugs and materials, bacterial infections remain a serious problem for wound healing. Most current materials cannot simultaneously provide antibacterial effects, reusability, and biocompatibility, and participate in stimulating cellular behaviour to promote bacterial wound healing. Herein, multifunctional nitrogen-rich carbon-coated bismuth/cobalt nanoparticles (Bi@Co@CN) with foam-like structures synthesised by a simple two-step method showed remarkably improved magnetic and photoconversion effects. These are promising candidates as photodynamic inactivation materials. Within 20 min, >99.999% Staphylococcus aureus (S. aureus) were killed by the composite due to its strong ability to generate reactive oxygen species (ROS) and thermal energy under simulated visible light. Additionally, Bi@Co@CN also displayed high stability: its antibacterial efficiency underwent rapid photodynamic inactivation over five cycles. In vitro results revealed that ROS and photothermal conversion of materials can seriously damage bacterial cell membranes and inhibit the virulence factors produced by bacteria, which ultimately leads to the death of S. aureus. Moreover, in vivo assessment of wound healing showed that the material was very effective for bacteria-accompanied wound healing and did not cause detectable damage to the major organs. Therefore, the Bi@Co@CN composite has great potential as a safe multimodal treatment system for active photodynamic inactivation and wound healing. [ABSTRACT FROM AUTHOR]

Abstract LiZn 1-x M x NbO 4 (M = Co, Ni) (x = 0–0.06) systems were fabricated by a facile solid-state reaction method. Structure and property relationships of spinel structured LiZn 1-x M x NbO 4 were investigated systematically. Appropriate amount of Co2+ and Ni2+ greatly improved the dielectric loss of LiZnNbO 4 ceramics. While, the dielectric loss deteriorated seriously when the doping content exceeded x = 0.02. The origin of dielectric loss in LiZn 1-x M x NbO 4 ceramics was investigated systematically. Moreover, the theoretical dielectric constant and linear expansion coefficient were calculated on the bases of the crystallographic parameters from XRD refinement. The temperature coefficient of resonant frequency calculated by the P-V theory agreed well with the test values. Due to the small doping content, the change in chemical bonds was negligible. Density became the major factor determining the variation of dielectric constant in LiZnNbO 4 ceramics. At last, excellent microwave dielectric properties were obtained: Ts = 1010 °C, ε r = 15.25, Q f = 107,000 GHz, τ f = −63.3 ppm/°C for LiZn 0.98 Co 0.02 NbO 4 and Ts = 995 °C, ε r = 14.85, Q f = 104,000 GHz, τ f = −61.7 ppm/°C for LiZn 0.98 Ni 0.02 NbO 4. Highlights • Structure and property of spinel structured LiZn 1-x M x NbO 4 are investigated. • The origin of dielectric loss in LiZn 1-x M x NbO 4 ceramics is clarified. • Dielectric constant and linear expansion coefficient are obtained by the P-V theory. • Excellent microwave performance make it a promising candidate for LTCC applications. [ABSTRACT FROM AUTHOR]

This study aims to evaluate the effects of ZrO 2 types including YSZ and nano-ZrO 2 as well as their contents on the phase compositions, macrostructures, microstructures, physical properties, mechanical properties and biocompatibility of Ti2448-ZrO 2 composites fabricated by spark plasma sintering (SPS). The mechanical properties such as hardness and compressive yield strength of the composites have been systematically investigated. The experimental results demonstrate that the hardness and compressive yield strength of the composites all dramatically increased with increasing the content of YSZ and nano-ZrO 2 . Meanwhile the nano-ZrO 2 could be beneficial to the uniformity of microstructure and improvement in mechanical strength of the composites. The biocompatibility of the composites containing nano-ZrO 2 was found to possess better corrosion resistance. In conclusion, Ti2448-ZrO 2 composites are potentially useful in biomedical applications with their mechanical and biological properties being evaluated in this work. [ABSTRACT FROM AUTHOR]

The development of gas sensors based on metal oxide semiconductor (MOS) with highly regular morphology, highly stable structures, and easy preparation is greatly desired but remains a challenge. Herein, we first prepared a highly regular array of TiO 2 nanorods on FTO by a modified in situ hydrothermal method. Then a uniform SnO 2 layer grew on the nanorods to form a core-shell nanocomposite by an ion-layer adsorption-reaction process. The TiO 2 /SnO 2 sensors show enhanced gas sensing performance compared with the TiO 2 sensors, including higher sensitivity to ethanol, lower working temperature, and better long-term stability. And the highest ethanol response can be obtained when the growth cycle of the SnO 2 shell was two times. The gas-sensing mechanism of the TiO 2 /SnO 2 nanocomposites was discussed concerning the unique core-shell structure and a heterojunction between TiO 2 and SnO 2. • Core-shell TiO 2 /SnO 2 nanorod arrays were prepared via a facile two-step method. • The TiO 2 /SnO 2 exhibited better ethanol sensing properties compared with pristine TiO 2. • The enhanced ethanol sensitivity mechanism of TiO 2 /SnO 2 was discussed detailed. [ABSTRACT FROM AUTHOR]

Powder metallurgy (PM) Ti–6Al–2Sn–4Zr–2Mo–0.1Si–(0, 2, 4)W (wt%) alloys were fabricated by thermomechanical consolidation of TiH 2 -based powder compacts and subsequent heat treatments. Samples of the as-fabricated alloys were also heated at 650 °C for 200 h. The addition of 2 or 4 wt%W to the base alloy changed its microstructure of parallel α/β lamellar colonies and grain boundary α (α GB) to an interwoven α/β t microstructure consisting of α GB and a network of interpenetrating α plates with β transformed structure (β t) domains comprising variants of fine α laths and β matrix. The partition of the β stabilizing W between β and α phases and the low diffusivity of W atoms limited the growth of α plates/laths, decreasing the thickness of α plates/laths and increasing the volume fraction of β. The increased hardening of the β phase and enhanced α/β interface strengthening associated with the 4 wt%W addition led to a significant increase in the tensile strength of the alloy from 1281 ± 10–1411 ± 12 MPa. However, the high flow stress and the very fine microstructure caused significant strain localization in the weak α GB , resulting in premature fracture of the α GB (intergranular fracture) and the low ductility (1.4%). Here, premature fracture meant the fracture occurred prior to the alloy reaching its ultimate tensile strength. The heating caused the β interlaths in the W-free alloy to partially dissolve and become β particles distributed along the original lines of β interlaths accompanied by the precipitation of α 2 -Ti 3 Al in the α plates. The addition of W inhibited the dissolution of β interlaths and caused the precipitation of a higher volume fraction of α 2 precipitates during heating. The microstructural changes caused by heating resulted in a slight decrease in strength and a significant decrease in ductility for the W-free alloy, but a significant increase of the yield strength of the 2 W and 4 W alloys with some sacrifice of the tensile ductility. The microstructural reasons for the effects on mechanical properties were analyzed with the assistance of detailed characterization of the dislocations in the deformed specimens. • Effects of W alloying on a PM Ti–6Al–2Sn–4Zr–2Mo–0.1Si alloy are investigated. • W refines α plates and enhances formation of β transformed structure domains. • W enhances hardening of the β phase and α/β interface strengthening. • W increases the microstructural stability and prevents the strength reduction from heating. • High W content promotes α 2 precipitation strengthening of the alloy after heating. [ABSTRACT FROM AUTHOR]

The phase composition, crystal structure and microwave dielectric properties of (1-x) (3ZnO-Nb 2 O 5 )-xGeO 2 were investigated systematically. The phase composition and phase transformation of (1-x) (3ZnO-Nb 2 O 5 )-xGeO 2 ceramics were confirmed by XRD refinement, SEM micrographs and EDS analysis. All sintered samples were composed of Zn 3 Nb 2 O 8 and ZnNb 2 O 6 phases. Phase transition between Zn 3 Nb 2 O 8 and ZnNb 2 O 6 was closely related the introduction of GeO 2 . When the doping content was low (x = 0–0.007), the phase transformation from ZnNb 2 O 6 to Zn 3 Nb 2 O 8 occurred, which was discovered for the first time. To clarify the phase transition, the local charge density and band structures were calculated using the CASTEP program. With the substitution of Ge 4+ , part of the electrons transferred from the oxygen atom to the middle of 'niobium-oxygen' and 'zinc-oxygen'. According, the covalency of 'niobium-oxygen' and 'zinc-oxygen' was enhanced. The shrinkage of ZnO 6 octahedron resulted in a decrease in the coordination number of zinc atoms. At last, the relationships between phase transition, crystal structure and the microwave performance were established. The system of 2.73ZnO-0.91Nb 2 O 5 -0.09GeO 2 sintered at 1150 °C for 6 h had excellent microwave dielectric properties: ε r  = 21.3, Q f  = 99,140 GHz, τ f  = −54 ppm/°C, which, to our best knowledge, the best performance with relative lower sintering temperature. [ABSTRACT FROM AUTHOR]

In real decision making, decision makers tend to express their opinions with uncertainty when facing complicated decision problem and environment. This paper develops a novel consensus reaching process for multiple attribute group decision making (MAGDM) with hesitant fuzzy linguistic term sets (HFLTSs). Firstly, we define a new distance measure for two HFLTSs and propose a distance-based consensus measure for the MAGDM with HFLTSs. Then, based on this consensus measure, we develop a minimum adjustment distance consensus rule for the MAGDM with HFLTSs, which can minimize the adjustment distance between the original and adjusted opinions in the process of reaching consensus. Moreover, to obtain the collective opinion with maximum consensus, we develop a minimum distance aggregation model, which is to minimize the maximum of the distance between each decision maker's individual opinion and the collective opinion. Furthermore, based on the proposed consensus rule and aggregation model, we present a consensus reaching process for MAGDM with HFLTSs. Finally, we provide the convergence proof of the consensus reaching process, and a numerical example is used to demonstrate the validity of the consensus reaching process. [ABSTRACT FROM AUTHOR]

Herein, for the first time, we report the synthesis, preparation, and characterization of fatty acid-conjugated poly(ethylene glycol)-block-poly(epsilon-caprolactone) nanoparticles (FA-NPs), with the ultimate goal of improving drug delivery to the brain. These nanoparticles had a nano-size (<100 nm) with a fairly narrow size distribution (PDI = 0.2–0.3). They were non-hemolytic and non-cytotoxic. By employing curcumin, a poorly soluble herbal molecule, as a model, FA-NPs enhanced the drug solubility by >5.4 × 10 5 x. They showed moderate stability in serum and exhibited zero-order drug release. As a proof-of-concept, the brain uptake of oleic acid-NPs (OA-NPs) was examined in rats after intravenous injections. Relative to 1% DMSO and PEG-NPs formulations, the OA-NPs enhanced the brain accumulation of the loaded cargo by 4.28 and 1.94x, respectively. Apparently, these nanoparticles hold considerable promise in drug delivery to the brain and their potential applications for disorders of the central nervous system should be explored. [ABSTRACT FROM AUTHOR]

A wide range of estimates on global wetland methane (CH 4 ) fluxes has been reported during the recent two decades. This gives rise to urgent needs to clarify and identify the uncertainty sources, and conclude a reconciled estimate for global CH 4 fluxes from wetlands. Most estimates by using bottom-up approach rely on wetland data sets, but these data sets show largely inconsistent in terms of both wetland extent and spatiotemporal distribution. A quantitative assessment of uncertainties associated with these discrepancies among wetland data sets has not been well investigated yet. By comparing the five widely used global wetland data sets (GISS, GLWD, Kaplan, GIEMS and SWAMPS-GLWD), it this study, we found large differences in the wetland extent, ranging from 5.3 to 10.2 million km 2 , as well as their spatial and temporal distributions among the five data sets. These discrepancies in wetland data sets resulted in large bias in model-estimated global wetland CH 4 emissions as simulated by using the Dynamic Land Ecosystem Model (DLEM). The model simulations indicated that the mean global wetland CH 4 emissions during 2000–2007 were 177.2 ± 49.7 Tg CH 4 yr −1 , based on the five different data sets. The tropical regions contributed the largest portion of estimated CH 4 emissions from global wetlands, but also had the largest discrepancy. Among six continents, the largest uncertainty was found in South America. Thus, the improved estimates of wetland extent and CH 4 emissions in the tropical regions and South America would be a critical step toward an accurate estimate of global CH 4 emissions. This uncertainty analysis also reveals an important need for our scientific community to generate a global scale wetland data set with higher spatial resolution and shorter time interval, by integrating multiple sources of field and satellite data with modeling approaches, for cross-scale extrapolation. [ABSTRACT FROM AUTHOR]

[Display omitted] • PEC catalysis of PET to produce formate was coupled with H 2 production. • FE for formate was up to 87% with Ni-Pi/α-Fe 2 O 3 photoanode. • The cell voltage of the PEC system was 270 mV lower than water splitting. • A PEC paradigm to upcycle real-world waste PET plastic was provided. There is no satisfactory treatment technology for plastic waste, which has been a global challenge so far. Here, we report a photoelectrochemical approach for efficient valorization of waste polyethylene terephthalate (PET) plastic to produce formate coupled with green hydrogen production. Due to the cocatalytic effect of nickel phosphate (Ni-Pi) on α-Fe 2 O 3 photoanode, the Faradaic efficiency of PET hydrolysate solution to formate reached as high as 87% in aqueous electrolyte without any additional oxidant. In addition, an integrated PET oxidation-hydrogen production system achieved a photocurrent density of 1.5 mA/cm2 at a cell voltage of 1.1 V, which is 270 mV lower than the conventional water splitting. Furthermore, we also demonstrate that high selective formate production was also applicable to real-world waste PET plastic. This work provides a sustainable paradigm on photoelectrochemical strategy to upcycle waste PET plastic into value-added chemicals and green hydrogen. [ABSTRACT FROM AUTHOR]

The durability of the current polymeric heart valves remains to be improved, which has proven to be highly dynamics and species dependent. Herein, inspired by the fiber-reinforced structure of native valve leaflets, we developed a valve prototype with the polymer matrix reinforced by NiTi wires in the radial direction, to achieve both desirable dynamics control and stress reduction. Textile technology and computer modeling were primarily utilized for integrated construction and biomimetic geometry. The NiTi-reinforced textile composites had suitable properties with valve leaflets. The pulsating flow tests confirmed that the systolic hemodynamics and leaflet kinetics were significantly optimized through the stiffness-domination of NiTi wires. Particle imaging velocimetry measurements revealed the satisfactory flow field characteristic for VP40-RA6 when compared with other reinforced valves. Furthermore, the finite element analysis indicated that the maximum principal stress and the area percentage of that were significantly reduced. As a preliminary proof-of-concept, this novel valve prototype exhibited excellent comprehensive performance which would be beneficial for the further improvement of long-term durability and provide new insight into the design modification of heart valve prosthesis. [Display omitted] • The valve prototype was built by integrated textile technology and computer modeling. • The valve prototype exhibited excellent hemodynamics indicators and leaflet kinetics. • The flow field characteristic was satisfactory. • The polymer matrix within the hybrid leaflet sustained lower stress level. [ABSTRACT FROM AUTHOR]

The development of efficient, environmentally friendly soil amendments is necessary in order to minimize the risk of metal contaminants (Cd, Pb, Cu, and Zn) to the soil ecosystem. As soil amendments, bovine bone meal (BM) and oyster shell meal (OS) reduced the mobility and bioavailability of metals primarily by increasing soil pH. Soil geochemical properties (pH, EC, CEC, Ca, P, and K) after amendment supplementation were more likely to affect metal migration than enzyme activity. Furthermore, BM and OS were found to suppress the Cd and Pb uptake by water spinach, keeping them below international standards for safe utilization. The protein and sugar content and peroxidase (POD) activity showed a significant negative correlation with the amount of metal in water spinach, whereas superoxide dismutase (SOD), ascorbate peroxidase (APX) activities and malondialdehyde (MDA) content exhibited a positive correlation with metal content in water spinach. We also found that BM and OS had less perturbation to phylum-level and genus-level bacterial composition during the remediation of heavy metals contaminated soil. Based on the above, we assume that BM and OS are eco-friendly soil amendments, which could improve soil nutrients contents, stabilize heavy metals and regulate bacterial community structure. Our research contributes to resource utilization of waste and holds promise for widespread application in current agricultural systems. [Display omitted] • BM and OS reduced the bioavailability of Cd, Pb, Cu, and Zn in soil. • BM and OS inhibited the uptake of Cd, Pb, Cu, and Zn by water spinach. • BM and OS reduced the abundance of metal-tolerant bacteria in soil. • Major geochemical factors altering the bacterial community were identified. [ABSTRACT FROM AUTHOR]

There is an urgent medical need to develop effective therapies that can ameliorate damage to the radiation-exposed hematopoietic system. Nanozymes with robust antioxidant properties have a therapeutic potential for mitigating radiation-induced hematopoietic injury. However, enhancing nanozyme recruitment to injured tissues in vivo while maintaining their catalytic activity remains a great challenge. Herein, we present the design and preparation of a biomimetic nanoparticle, a mesenchymal stem cell membrane camouflaged Prussian blue nanozyme (PB@MSCM), which exhibits biocompatible surface properties and demonstrates enhanced injury site-targeting towards the irradiated murine bone marrow niche. Notably, the constructed PB@MSCM possessed redox enzyme-mimic catalytic activity and could scavenge overproduced reactive oxygen species in the irradiated bone marrow cells, both in vitro and ex vivo. More importantly, the administration of PB@MSCM significantly mitigated hematopoietic cell apoptosis and accelerated the regeneration of hematopoietic stem and progenitor cells. Our findings provide a new targeted strategy to improve nanozyme therapy in vivo and mitigate radiation-induced hematopoietic injury. [ABSTRACT FROM AUTHOR]

This paper reports a facile two-step synthesis route for the preparation of flower-like ZnO/α-Fe 2 O 3 nanorods (NRs). Flower-like ZnO NRs with the average diameter about 810 nm and length about 4.5 µm were firstly synthesized via a chemical solution method, and then ZnO NRs was coated with a continuous α-Fe 2 O 3 layer to form ZnO/α-Fe 2 O 3 core-shell structure through an ionic-layer adsorption and reaction method. The gas-sensing results show that the ZnO/α-Fe 2 O 3 NRs exhibit excellent sensitivity, selectivity, and response-recovery capacity to ethanol vapor at a low optimum temperature of 240 °C. In particular, compared with pure ZnO NRs and α-Fe 2 O 3 nanoparticles (NPs), the ZnO/α-Fe 2 O 3 NRs show an obvious improvement in gas sensing properties. The substantial improvement of sensing properties may be attributed to the unique microstructure and heterojunction formed between ZnO and α-Fe 2 O 3 . [ABSTRACT FROM AUTHOR]

A novel lead-free, high dielectric constant, ultra-wide temperature stable dielectric ceramic Ba 1−x Bi x Ti 1−x −y Zn 0.75x W 0.25x+y O 3+y (0.22≤x≤0.30, y=0.015) was synthesized by the traditional solid-state reaction method. The phase composition, electric and dielectric properties of the Ba 1−x Bi x Ti 1−x −y Zn 0.75x W 0.25x+y O 3 ceramics were investigated. The P-V-L dielectric theory was introduced. And, the chemical bond energy was calculated to track the changes in micro-structure. The relationships between chemical bond energy and the macroscopic dielectric properties(ε r , dielectric stability and dielectric loss ) in Ba 1−x Bi x Ti 1−x−y Zn 0.75x W 0.25x+y O 3+y ceramics were discussed systematically. Owing to the inhomogeneous micro-structure and the diffusion in phase transition, Ba 1−x Bi x Ti 1−x−y Zn 0.75x W 0.25x+y O 3+y ceramics showed a stable permittivity (~800±15%) over a ultra-wide temperature range (−30 to 375 °C). Moreover, dielectric loss was less than 0.02 and the insulation resistance was over 10 12 Ω cm. These features suggested that the Ba 1−x Bi x Ti 1−x−y Zn 0.75x W 0.25x+y O 3+y ceramic could be considered as a promising candidate material for energy storage applications in harsh environment. [ABSTRACT FROM AUTHOR]

Multi-component BaTiO 3 –Bi 0.5 Na 0.5 TiO 3 –Nb 2 O 5 (BBNN) system doped with divalent metal ions (Zn 2+ , Co 2+ , Ni 2+ ) was prepared by the conventional solid–state method.The X-ray diffraction patterns revealed all samples exhibited perovskite (P4mm) single phase. The dielectric properties and micro-mechanisms were discussed and validated. Novel theories, based on the characteristics of the different kinds of dielectric polarization, are proposed to explain the dielectric anomalies in the dielectric system. The relationships between microstructure and the dielectric properties were investigated systematically for the first time. The samples doped with 15 mol% Zn 2+ /Co 2+ presented good dielectric properties of an ultra-broad temperature stable range (from −50 and >300), high dielectric constant (ε~1925 for Zn 2+ / ε~1341 for Co 2+ ) and low dielectric loss (tan δ<0.02) were obtained. These features made the ceramics system have high practical values for miniaturization and harsh environments applications. [ABSTRACT FROM AUTHOR]

Two samples of an α + β Ti-4Al-4Mo-4Sn-0.5Si (wt%) alloy, one with fine prior β grains and a heterogeneous microstructure and the other with coarse prior β grains and a homogeneous microstructure were prepared by extrusion of compacts of TiH 2 /Al/Mo/Sn/Si powder blend at 1200 and 1300 °C respectively. The heterogeneous microstructure is manifested by softer Mo-rich regions with a full α/β lamellar structure containing a high number density of parallel and nanometer sized FCC δ (TiH) needles in a harder matrix with a microstructure consisting of interweaved α plates and β transformed structure (β t) domains and grain boundary α (GB α) layers. The matrix also contains a small fraction of Sn-rich regions which have the same microstructure as the matrix. The Mo-rich and Sn-rich regions form due to the limited diffusion of Mo and Sn alloying elements. This heterogeneous microstructure sustains a high tensile yield strength of 1199 MPa, a high strain hardening rate, and an excellent tensile ductility of 12.0%. In contrast, the homogeneous microstructure comprising of interweaved α plates and β t domains together with GB α layers sustains a similar high strength, but a clearly lower strain hardening rate and a significantly lower tensile ductility of 3.5%. Non-homogeneous deformation capacity, the release of energy by forming numerous microcracks and the intermittent growth of microcracks of the heterogeneous microstructure suggest that this microstructure has a high plasticity and high resistance to the growth of microcracks. • The α + β titanium alloy fabricated has a heterogeneous microstructure and fine prior β grains. • The heterogeneous microstructure encompasses softer Mo-rich regions in a matrix of α/β t microstructure. • This alloy exhibits a superior combination of high strength (YS: 1199 MPa and excellent ductility (12.0%). • This is attributed to the compatible deformation and high microcrack growth resistance of the microstructure. [ABSTRACT FROM AUTHOR]

As cities continuously expand and with the emergence of mega-city regions, the urban functional zones (UFZs) have spread beyond their original administrative boundaries. An accurate and updated delineation of the UFZs is crucial for assessing the functional integration between cities within a mega-city region. Mobility data provides a chance to depict the UFZs from actual human activities at a finer spatial scale. Existing studies mostly adopted network-based approaches relying on the topological relationship but ignoring spatial factors, causing the lack of sensitivity in detecting the cross-cities integration of the functional region. This research proposed a novel regionalisation algorithm that redraws non-overlap boundaries of urban functional zones based on the commuting origin-destination matrix, representing the spatial interactions within cities and cross-cities. In particular, functional zones are drawn by searching for the best partition with the best goodness of fitting in the hierarchical spatial interaction model. The algorithm was applied to a case study of a mega-city region, Shenzhen-Dongguan-Huizhou (SDH) area in China using mobile phone signalling data. By adopting two different settings, this model evaluated the current status and predict the future trend of urban integration respectively. The results show the current boundary of UFZs in the SDH area almost coincides with administrative boundaries. Meanwhile, the results of long-term predictions might be utilised by policymakers to give more attention to the areas near the Dongguan-Huizhou boundary to promote industry cooperation and avoid mismatches between the functional and administrative regions. • A hierarchical spatial interaction model for delineating urban functional zones. • An iteration-based algorithm for searching for the best partition of urban functional zones. • Using emerging mobile phone data for urban planning applications. • A case study of the SDH Area provides insights into cross-boundary city integration and related policy implications. [ABSTRACT FROM AUTHOR]

Sulfur-rich polymers, synthesized through inverse vulcanization, with tunable heteroatom containing crosslinkers were investigated as the S-containing cathode active material within Li–S cells. The polymers possess up to 73% active sulfur while, importantly, not containing any unreacted, crystalline sulfur. Li–S-polymer cells achieve specific capacities of 1206 mAh g s −1 for an active material polymer containing 80 wt% sulfur, with 10 wt% of a structural crosslinker (dicyclopentadiene), and 10 wt% of an oxygen-containing crosslinker (ethylene glycol dimethacrylate). The high capacity achieved within this composition is associated with of this sample, in a higher average sulfur rank within the polymer structure. Furthermore, S-polymers with heteroatomic crosslinkers exhibited lower capacity fade (0.093% per cycle) compared with polymers without functionalized heteroatomic crosslinkers (0.165% per cycle) and elemental sulfur (0.312% per cycle). X-ray photoelectron spectroscopy showed the inherent binding between the ester group carbonyl oxygen within the crosslinker to the long-chain lithium polysulfides, which may inhibit dissolution of these intermediates. • Sulfur polymers with heteroatom containing crosslinkers as cathode in Li–S cells. • Longer sulfur chains benefit electrochemical performance. • Chemical affinity of carbonyl groups impedes dissolution of polysulfides. • Highest specific capacity 1206 mAh g s −1, 0.093% capacity loss per cycle. [ABSTRACT FROM AUTHOR]

• With an addition of 0.2 wt%Si, the Si atoms are equally in α and β phases. • Si solute atoms retard the growth of α phase, causing refinement of the α/β t lamellar structure. • Si atoms enhance solid solution strengthening and Si atoms enhanced α/β t interface strengthening. • Increasing the Si content to 0.5 wt% cause a further increase of the yield strength by 50 MPa. • With a high strength, the tensile ductility deteriorates, due to the premature fracture of grain boundary α layers. Ti-4Al-4Mo-4Sn-xSi (wt%) (x = 0, 0.2, 0.5) alloys were fabricated by hot extrusion of compacts of blends of TiH 2 , AlMo60 master alloy and other required elemental powders followed by heat treatments involving vacuum annealing, solution treatment, air cooling and aging. The microstructure of the alloys consists of α plates, lamellae of α and transformed β structure (β t), β t blocks as well as grain boundary α layers. With the addition of 0.2 wt%Si, the Si atoms exist in equal concentration in both α and β t regions as solute atoms, and they retard the growth of α phase, causing a decrease of the average thickness of α plates and lamellae and slight increase of the volume fraction of β t lamellae and blocks. The solid solution strengthening and enhanced α/β interface hardening brought by the 0.2 wt%Si cause the yield strength of the Ti-4Al-4Mo-4Sn alloy to increase significantly from 1030 to 1130 MPa with a slight decrease of the tensile ductility (7.4% vs 6.8%) and without changing the fracture behavior. With the addition of 0.5 wt%Si, the extra Si causes nanometer sized silicide (Ti 5 Si 3) precipitates to form in both α and β t regions and further microstructural refinement. The additional α/β interface hardening and precipitation hardening cause the yield strength of the alloy to increase further to 1177 MPa, but the tensile ductility deteriorates clearly with the elongation to fracture decreasing to 4.9%. The main reason for this ductility decrease is the premature fracture of grain boundary α layers caused by the higher flow stress which can induce more strain localization at the grain boundary α layers. [ABSTRACT FROM AUTHOR]

Highlights: [•] A novel quaternary chalcogenide KBiCu2S3 has been synthesized via a facile hydrothermal approach. [•] The critical influencing factors for the crystal growth were discussed in detail. [•] The magnetic and electrical properties of KBiCu2S3 were also studied. [•] The band gap of the compound is 1.29 eV. [•] Its photoelectric response was also characterized, which demonstrated the potential for applications in photovoltaic devices. [ABSTRACT FROM AUTHOR]

• We focus on the unification and fusion of heterogeneous distributed linguistic information. • We present several minimum information-loss transformation models with desirable properties. • We present a multi-attribute group decision making framework in a heterogeneous distributed linguistic context. • We demonstrate the necessity of flexibility in distributed linguistic decision making. In the problems that linguistic assessments are conducted by adopting multiple sources of information representations, the management of unification of heterogeneous information and information loss are necessary. To support a useful fusion of heterogeneous distributed information in linguistic group decision making, a minimum information-loss transformation framework is proposed in this paper. First, distributed linguistic distance measurements are defined to measure information loss among heterogeneous distributed linguistic preference information, and then several minimum information-loss transformation models (MILTMs) with desirable properties are proposed. Furthermore, the application of the MILTMs in addressing the fusion of heterogeneous distributed linguistic information in a multi-attribute group decision context is discussed, and the flexibility of distributed linguistic information is studied to justify the MILTMs through numerical examples and comparative analyses. [ABSTRACT FROM AUTHOR]

Halide perovskite quantum dots have attracted considerable research interest as excellent candidate for photonic and optoelectronic applications due to their unique optoelectronic properties. Stability is prerequisite and therefore is of critical importance. Here we demonstrate highly stable luminescent CsPbBr 3 quantum dots (QDs) can be achieved in different glass matrices via the high temperature melting process and melt-quench method. The microstructure of CsPbBr 3 QDs glass as well as their optical properties are systematically characterized by microscopic techniques and time-resolved spectroscopic techniques. We conclude the surface passivation is the key aspect for the high stability and high luminescence by embedding the quantum dots in the glass matrix. This study provides technical method to form highly stable luminescent solid devices and detailed physical understanding which is critical for the practical applications. • Luminescence in CsPbBr 3 QDs glass were study. • CsPbBr 3 QDs precipitated in 3 kinds of glass matrices. • Exciton recombination is confirmed as the dominant radiative mechanism. • the QDs glass could be flexibly fabricated into various device. [ABSTRACT FROM AUTHOR]

Polyanion Na 3 V 2 (PO 4) 3 belongs to sodium-ion super conductor (NASICON) materials, and its NASICON framework offers a stable sodium capacity. The open three-dimensional (3D) channels can provide the transfer paths for sodium-ions. Besides, the unique 3D structure is helpful to achieve the high reversibility of charge and discharge processes. As the cathode compounds for sodium-ion batteries (SIBs), Na 3 V 2 (PO 4) 3 materials meet requirements of low cost and high safety. Moreover, Na 3 V 2 (PO 4) 3 materials possess a high voltage platform and have been widely concerned in SIBs. It is deemed that Na 3 V 2 (PO 4) 3 is a promising cathode material for SIBs. However, the low electronic conductivity of Na 3 V 2 (PO 4) 3 materials hampers the rate capability. Herein, the recent researches of Na 3 V 2 (PO 4) 3 are roundly reviewed. Firstly, this paper introduced the structural characteristics of Na 3 V 2 (PO 4) 3 materials. And then synthetic methods were narrated, such as sol-gel, spray-drying, hydrothermal, electrospinning, and solid-state reaction methods. Moreover, the modified researches of Na 3 V 2 (PO 4) 3 were summarized, mainly including carbon coating, nanocrystallization, and ionic doping. Finally, we prospected the future development direction of Na 3 V 2 (PO 4) 3 modification methods, and made a few suggestions. • The transfer mechanism of sodium ions in Na 3 V 2 (PO 4) 3 is explained in more detail. • The methods of experimental synthesis of Na 3 V 2 (PO 4) 3 materials are reviewed. • The latest research progress in modification methods of Na 3 V 2 (PO 4) 3 as cathodes materials for sodium ion battery is reviewed. • Several suggestions on the modification of Na 3 V 2 (PO 4) 3 materials are put forward. [ABSTRACT FROM AUTHOR]

The bi-layer composite ceramic armors are widely used in the protection field, and its design method is keep changing since the Florence model has been found. In this study, an analytical design method of bi-layer was proposed and examined with a new ceramic protection efficiency definition. With this definition, the protection efficiency of composite ceramic armor can be divided into two independent parts: the protection efficiency of ceramic and the protection efficiency of backing plate. By using this analytical design method, the design of the bi-layer ceramic armor can be more efficiency and the material of armor can be selected more accurately. [Display omitted] • A design method for bi-layer ceramic armors is established. • Proposed method was verified using numerical simulation and bullet impact experiments. • Analytical solution was in predicting total armor protection efficiency per unit area density. [ABSTRACT FROM AUTHOR]

W–Re alloys find wide application in high-temperature measurements and as components of engines and aircraft. However, their low oxidation and thermal shock resistances have limited their application at high temperatures in oxidized atmospheres. In this work, an inner WSi 2 coating was first prepared on the surface of the W-26Re alloy by pack cementation. Subsequently, an outer ZrB 2 -HfO 2 -SiC (ZHS) coating was prepared by the sol-gel method and blade coating, using self-prepared nano-HfO 2 fibers introduced in different ratios (0%, 3%, 6%, and 9%). Following thermal shock tests at 1073–1773 K, the coatings toughened by nano-HfO 2 fibers with high melting point (above 3000 K) showed better thermal shock resistance, especially the 6% HfO 2 -doped coatings. The 6%Hf-ZHS coating underwent the highest number of thermal shock cycles (369), 385.5% and 210.1% higher than those experienced by W-26Re and ZHS. In addition, the thermal shock resistance of ZHS was 56.6% better than of the bare W-26Re alloy. Finally, the protection mechanism of the above coatings was explained by scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray diffraction analyses. [ABSTRACT FROM AUTHOR]

Antiferroelectric film capacitors have attracted increasing attention due to their excellent energy storage properties. In this work, PbZrO 3 (PZO) antiferroelectric films have been prepared on the flexible fluorphlogopite (Mica) and rigid Pt/Ti/SiO 2 /Si substrates with a seed layer of LaNiO 3 (LNO) layer by sol-gel process. The microstructure and energy storage properties of the films have been systematically studied. The results show that the Mica-Pt-LNO-PZO (M -LNO-PZO) thin film has an improved energy storage density (W rec) of 16.6 J/cm3 with a charge and discharge efficiency (η) of 50.4%. Furthermore, the flexible thin films exhibit good stability under a wide working temperature range of 25–140 °C and an electric fatigue endurance of 107 cycles. Besides, the capacitive films can endure a bending radius of 4 mm and 104 bending cycles (@ r = 4 mm) with almost unchanged in the energy storage properties. The excellent energy storage properties endow inorganic thin films with great potential in flexible electronic devices. [ABSTRACT FROM AUTHOR]

Heterogeneous aging of organic aerosols can significantly alter their physicochemical properties and thus their impacts on the radiative balance of the earth system. In this study, kinetics and mechanisms of heterogeneous reactions between suspended squalane particles and hydroxyl (OH) radicals were investigated using a self-made photooxidation flow tube and a high-resolution long time-of-flight chemical ionization mass spectrometer equipped with a Filter Inlet for Gases and AEROsols (FIGAERO-HR-LToF-CIMS). In addition to the measurements of the heterogeneous reaction rate constants for squalane and its multi-generation functionalization products whose carbon backbone are retaining, identification and semi-quantification of functionalization and fragmentation products from OH radical-initiated aging of squalane were carried out, which were utilized to develop a plausible reaction scheme. Our results show that the heterogeneous oxidation mechanism for particulate squalane is similar to those for OH radical initiated-oxidation of gaseous alkanes, but intermolecular hydrogen abstraction, in addition to reactions with O 2 , isomerization, and decomposition, could be an important heterogeneous reaction pathway for alkoxy radicals, leading to the formation of functionalization products of alcohols. The relative abundances of fragmentation products suggest that OH radicals preferably attack the tertiary carbon. The evolution of products indicates that functionalization plays a leading role in the early stage of the reaction and the fragmentation products become more and more important with increased OH exposure. Our study depicts heterogeneous reaction pathways of organic aerosols with OH radicals at the molecular level, and helps to better understand the chemical evolution of complex organic aerosols in the atmosphere. • Hydroxyl radical-initiated aging of particulate squalene was investigated. • A plausible reaction scheme was developed. • Intermolecular hydrogen abstraction is important for particulate alkoxy radicals. • Functionalization plays a leading role in the early stage of the reaction. [ABSTRACT FROM AUTHOR]

Pt-loaded curling-like Bi 2 WO 6 (BWO) microdiscs were fabricated via a simple one-step hydrothermal and impregnation route. Various characterization methods, such as XRD, EDS and TEM, were conducted to prove the successful Pt loading. Electron migration from the semiconductor BWO to the precious metal Pt was revealed by the blue shift of the Bi 4f and W 4f XPS peaks with the increase of the Pt loading amount and the ∼10-fold baseline resistance elevation of the BWO-based sensor by the Pt loading, proving the formation of Schottky junction. Among the pristine BWO and Pt-loaded BWO with different Pt loading amounts, 1 wt % Pt-loaded BWO exhibits the highest gas response of 209 in sensing 500 ppm triethylamine at 300 °C, a minimal selectivity coefficient of 130.6 against some typical interfering gases at the same concentration and a low detection threshold of 1 ppm. Additionally, the sensitization mechanism is discussed as the synergistic effect of noble metal catalytic effect and metal-semiconductor junctions. [Display omitted] [ABSTRACT FROM AUTHOR]

Hafnium oxide (HfO 2) fibers can be widely used in ultra-high temperature ceramics (UHTCs) as reinforced material in order to achieve better antioxidant performance and less cracks and flaking on surface of UHTCs in field of ultra-high temperature thermal protectors. Calcination temperature is one of essential parameters for forming HfO 2 fiber. In this work, one-dimensional (HfO 2) fibers were prepared through the electrospinning method and further post-calcination treatment. During the calcination treatment, the monoclinic-HfO2 (m-HfO 2) was formed from as-spun HfO 2 fibers at 432 °C, and only a small amount of m-HfO 2 was converted into the tetragonal HfO 2 at 1013 °C, which can increase the fiber density and decrease the grain size. However, the remaining m-HfO 2 was directly converted into the cubic HfO 2 at 1351 °C. The unique temperatures of forming monoclinic, tetragonal, cubic phase were much lower than the phase-transition temperature. The prepared HfO 2 fiber could still maintain fibrous morphology after 10 times cyclic thermal shock in air. Moreover, the fibers calcined at 900 °C and 1200 °C have better thermal shock resistance for their stable phase and fibrous morphology with uniform grain growth after the thermal shock test. [ABSTRACT FROM AUTHOR]

A major difficulty in integrating large scale wind power generation in an electrical power system is that wind generated power appears to be erratic, intermittent, and volatile. In this paper, we demonstrate the efficacies of a novel ultra short term 1-step ahead wind generated power prediction model, by combining two best of breed machine learning models in their respective areas of applications: a deep convolutional neural network (CNN) model, known to be effective in classification problems, and a bi-directional long short term memory (Bi-LSTM) model, known to be effective in 1-step ahead time series prediction problems, using a cross attention (XA) mechanism on three challenging practical datasets: the East-China dataset, the Yalova (Turkey) dataset, and the 16 MW dataset. There are two alternative cross attention models: (1) using the CNN features as the key–value pair, and the Bi-LSTM features as the query, this we called a XA model, and (2) using the Bi-LSTM features as the key–value pair, and the CNN features as the query, this we called a XA_I model; we found empirically for a properly chosen sliding window length, whichever CNN model or Bi-LSTM model performs well in the 1-step ahead prediction, then its features should be used as the query in the cross attention mechanism, thus, the XA achieves better results than XA_I on the East-China dataset, while XA_I achieves better results than XA on the Yalova dataset, and on the 16 MW dataset. Where comparable results using other state-of-the-art models are available on the Yalova dataset and the 16 MW dataset, we found that our XA_I results are superior. Moreover, it is found empirically, that the cross attention mechanism model produces stable k -step ahead predictions, for k ≤ W 2 , where W is the sliding window length. • A novel prediction model for wind generated power based on cross attention mechanism has been proposed. • The proposed method demonstrated on three practical datasets to have superior performance. • The cross attention mechanism based models give a stable multi-step ahead prediction. [ABSTRACT FROM AUTHOR]

[Display omitted] • A new method was proposed for preparing modified clays to control harmful algae blooms: single source with series modifications. • Kaolin that was modified by the new method could remove over 85% of Prorocentrum donghaiense cells. • Calcination, acid–alkali treatment, and the supplementation of raw kaolin during aging were indispensable processing steps in the new method. • A schematic mechanism of kaolin modification by the new method to obtain modified clay with high algal cell removal efficiency was illustrated. Modified clay (MC) is an effective and eco-friendly material that is widely used for controlling harmful algae blooms (HABs). In this study, a new method—single source with series modifications (SSSM)—was optimized for preparing a high-quality MC, and aluminum-rich clay (kaolin) was activated with a multistep treatment that included calcination (Cal), acid etching with alkali neutralization (Al–An), and raw clay supplementation and aging (RSA). The results showed that the removal efficiency of Prorocentrum donghaiense by the SSSM–MC exceeded 85%; Cal, Al–An, and RSA were indispensable processing steps for preparing the best MC with the SSSM method. The changes occurring in the mineral structure and chemical composition of kaolin treated by the different steps were characterized by FT-IR, XRD, 27Al-NMR and Al-Ferron. Surface dehydroxylation and disruption of the kaolin lattice after calcination significantly changed the aluminum structure from AlVI to AlV and AlIV. The relatively reactive AlV was readily released from the kaolin lattice with acid etching, and it subsequently reacted with external OH– to generate different polyhydroxyaluminum species because alkali was added during the Al–An step. The acidity of the above complex was further decreased by RSA, greatly increasing the yield of SSSM–MC while assuring the quality. [ABSTRACT FROM AUTHOR]

Graphical abstract Abstract The objective of this study is to investigate the differences of emulsion stability evaluated by phase separation proportion and Turbiscan Stability Index (TSI). The relationship between emulsion stability and oil displacement efficiency was also investigated. An alkaline-surfactant-polymer (ASP) solution and a surfactant-polymer (SP) solution were both selected to prepare emulsions, respectively. The instability process of emulsions was studied by the multiple light scattering as well as the bottle test. The opposite stability results, evaluated by the TSI and the phase separation proportion separately, of same emulsion are observed. The discrepancies resulted from diverse influence of emulsion instability types in test methods. The main instability type in ASP emulsions is creaming, whereas in SP emulsions is flocculation and coalescence. The influence of creaming is more notable in bottle test. However, in TSI calculation, not only creaming but also flocculation and coalescence are recorded and counted particularly. The stability results obtained by the bottle test and the multiple light scattering method were similar for emulsions prepared with different concentrations of ASP or SP solution. Injection pressure change in core flooding experiments can be better explained by TSI of the emulsion. [ABSTRACT FROM AUTHOR]

Bi ions-doped materials have attracted increasing attention because of their potential applications in LED light sources and imaging displays. However, the correlation between local glass network structure and visible emission of Bi ions is rarely discussed, which hinders the optimization of Bi ions-doped glass. In this work, we prepared the Bi ions-doped borosilicate glasses (Bi-Glass) with tunable visible emissions by changing the content of B 2 O 3. Their optical properties, structure, and temperature-dependent emission were investigated systematically. All the Bi ions-doped glasses show broadband luminescence from 350 nm to 700 nm, the emission bands show a blue shift from 454 nm to 435 nm when the concentration of B 2 O 3 increases from 0% to 10%. The emission intensity reaches the maximum value of 5% B 2 O 3 concentration, which attributes to the number and distribution of bismuth ions luminescent centers. Furthermore, thermoluminescence is observed in this glass system. In this study, the coordination structure around the active centers of bismuth can be changed by modifying the glass network structure, promoting the research of tunable luminescence of bismuth ions-doped glass. [ABSTRACT FROM AUTHOR]

BaSn 0.15 Ti 0.85 O 3 (BTS) thin films were deposited on Pt/Ti/SiO 2 /Si(1 0 0) substrate by pulsed laser deposition and the effects of substrate temperature on their structure, dielectric properties and leakage current density were investigated. The results indicate that the substrate temperature has a significant effect on the structural and dielectric properties of the BTS thin films which exhibit a polycrystalline perovskite structure if the substrate temperature ranges within 550–750 °C. The dielectric constant and loss tangent of the BTS thin films deposited at 650 °C are 341 and 0.009 at 1 MHz, respectively, the tunability is 72.1% at a dc bias field of 400 kV/cm, while the largest figure of merit (FOM) is 81.1. The effect of the substrate temperature on the leakage current of the BTS thin films is discussed. [ABSTRACT FROM AUTHOR]