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Computers, televisions, and smartphones are revolutionized by the invention of InGaN blue light‐emitting diode (LED) backlighting. Yet, continual exposure to the intense blue LED emission from these modern displays can cause insomnia and mood disorders. Developing "human‐centric" backlighting that uses a violet‐emitting LED chip and a trichromatic phosphor mixture to generate color images is one approach that addresses this problem. The challenge is finding a blue‐emitting phosphor that possesses a sufficiently small Stokes' shift to efficiently down‐convert violet LED light and produce a narrow blue emission. This work reports a new oxynitride phosphor that meets this demand. K3AlP3O9N:Eu2+ exhibits an unexpectedly narrow (45 nm, 2206 cm−1), thermally robust, and efficient blue photoluminescence upon violet excitation. Computational modeling and temperature‐dependent optical property measurements reveal that the narrow emission arises from a rare combination of preferential excitation and site‐selective quenching. The resulting chromaticity coordinates of K3AlP3O9N:Eu2+ lie closer to the vertex of the Rec. 2020 than a blue LED chip and provides access to ≈10% more colors than a commercial tablet when combined with commercial red‐ and green‐emitting phosphors. Alongside the wide gamut, tuning the emission from the violet LED and phosphor blend can reduce blue light emissions to produce next‐generation, human‐centric displays. [ABSTRACT FROM AUTHOR]

• Co catalysts with different size and morphology are used to reproduce C1-C16 alkanes from CO 2 and water under solar light. • We find a mechanism that involves a CO 2 assisted galvanic replacement and a gas-phase CO 2 hydrogenation reaction, but without evident contribution from plasmonic hot charge carriers. • The low H 2 /CO 2 ratio (e.g. 1/7) in the system was responsible to the production of C2+ long-chain alkanes. • Co is slowly but inevitably converted to CoCO 3. The production of long-chain hydrocarbons from CO 2 and water using solar light is a big challenge for the catalysis society. Cobalt nanostructures have been reported to catalyze the production of C3-C15 alkanes in a cobalt-water-CO 2 three-phase system under white light, yet the proposed photocatalytic mechanism still lacks evidence. In this work, cobalt micro- and nanostructures with different sizes and morphologies are used as model catalysts to reproduce this reaction. Despite different activity, selectivity and stability, the catalysts are found to follow the same reaction mechanism: a CO 2 assisted galvanic replacement reaction to produce H 2 followed by a thermal catalytic CO 2 hydrogenation to produce alkanes; meanwhile, the Co catalysts are gradually but inevitably converted to CoCO 3 , leading to a slow deactivation. The low concentration of the in-situ formed H 2 favors the growth of C2+ alkanes. The incident light drives the reaction by heating the catalyst, rather than providing plasmonic hot electrons for CO 2 reduction. [ABSTRACT FROM AUTHOR]

Background: Streptococcus suis is an emerging zoonotic agent. Its natural habitat is the tonsils, which are the main portals of S. suis entry into the bloodstream of pigs. The remarkable variability of the bacteria and complex pathogenic mechanisms make the development of a vaccine a difficult task.Method: Five conserved virulence factors involved in critical events of S. suis pathogenesis were combined and used as an intranasal vaccine (V5). The effect of V5 was investigated with intranasal and systemic challenge models.Results: V5 induced antibody and T-cell responses at the mucosal site and systemically. The immunity promoted clearance of S. suis from the nasopharynx independent of S. suis serotypes and reduced lethality after systemic challenge with S. suis serotype 2. Moreover, mice that survived sepsis from intravenous infection developed meningitis, whereas none of these mice showed neuropathological symptoms after V5 receipt.Conclusion: Intranasal immunization with multiple conserved virulence factors decreases S. suis colonization at the nasopharynx across serotypes and inhibits the dissemination of the bacteria in the host. The protective mucosal immunity effects would potentially reduce the S. suis reservoir and prevent S. suis disease in pigs. [ABSTRACT FROM AUTHOR]

Abstract In this work, CdO-Ag-ZnO nanocomposites with hierarchically porous structure and large surface area were successfully fabricated by solution combustion synthesis (SCS) method. Crystalline structure, morphology, surface chemical states and specific surface area were investigated by XRD, SEM, TEM, XPS and BET techniques, respectively. Sensors fabricated from CdO-Ag-ZnO nanocomposites were made based on indirect heating method, which showed superior sensing properties in detecting different concentration of volatile organic compounds (VOCs). In contrast with singular ZnO, gas-sensing experiment results reveal that the addition of CdO and Ag effectively decreases optimum working temperature, increases gas response value and shortens response and recovery time. What's more, other gas-sensing properties including repeatability, sensitivity and long-term stability are also discussed in this research. Particularly, gas sensor based on 10 mol% CdO-Ag-ZnO shows modest gas-sensing performance to VOCs at the operating temperature of 200 °C, and its gas response values are 198.63, 156.07, 53.04, 64.23, 183.65 towards 100 ppm formaldehyde, ethanol, acetone, methanol and isopropanol, respectively, indicating it a promising candidate in detecting VOCs. Superior sensing property is mainly ascribed to large specific surface area, special porous surface morphology, unique combination of nanocomposites and good catalytic ability of metallic Ag. [ABSTRACT FROM AUTHOR]

[Display omitted] • Using PTASA to promote PTL pyrolysis for high-quality syngas was firstly proposed. • The kinetic mechanism of PTASA in the pyrolysis of PTL was revealed. • PTASA mainly decreased the activation energy of Lignin in PTL by19%. • High-quality syngas increased evidently from 0.415 to 0.523 L/g with PTASA. • Inherent minerals in PTASA could break macromolecule bonds to promote PTL pyrolysis. To improve pyrolysis syngas of Phoenix Tree's Leaves (PTL), the synergistic effect of Purified Terephthalic Acid Sludge Ash (PTASA) was comprehensively investigated. In kinetics analysis, the thermal decomposition of PTL could be divided into three pseudoreactions while PTL + PTASA was with four pseudoreactions owing to the decomposition of CaCO 3 as well as the reduction of inherent metal compounds (Co(II), Mn(III, IV), etc). Meanwhile, the reaction models for pseudoreaction 1 (P1) ∼ pseudoreaction 4 (P4) were fitted as D3, R2 and D3, and A15, respectively. The Ea (average activation energy) of PTL + PTASA during pyrolysis (200 ∼ 600 °C) was 6.2 % lower than the monopyrolysis which was mainly caused by the decrease of Ea in the decomposition of lignin. In addition, the crystal structure e.g. CaMnO 3 (ABO 3), Ca 3 Co 2 O 6 (A 3 BB'O 6), and CoO in PTASA could effectively promote the production of high-quality syngas from 41.34 % to 61.76 %. Moreover, the reaction pathways in pyrolysis of PTL + PTASA showed that the PTASA could promote the C C bond, C O bond, and C–H bond breaking of the macromolecules, e.g. anhydrosugars, N-containing compounds, and aldehydes, to produce the small molecules and release syngas. This study could provide a useful strategy for clean, valuable, and sustainable resource utilization of waste resources. [ABSTRACT FROM AUTHOR]

This paper reported the synthesis and gas-sensing properties of Pt nanoparticles modified Al-doped ZnO (AZO) macro-/mesoporous nanosheets, which were prepared via a solution combustion approach with a subsequent heat treatment at 400 °C for 50 min. The high performance in detecting butane were achieved for the well-adhered products with unique porous surface appearance on the sensors fabricated using indirect heating method, which demonstrated the superiority of solution combustion synthesis (SCS) in synthesizing complex oxides. The possible explanations of the high butane gas-sensing characteristics of these sensors were based on the results of BET and XPS. The large surface area could provide sufficient interface between the materials and butane gas, and the adsorbed oxygen species having strong oxidation activity could break the butane molecules into CO 2 and H 2 O. The gas-sensing properties of Pt-modified AZO were investigated by testing the gas responses towards butane. The maximum response of the 5% Pt-AZO based gas sensor reached 56.52–3000 ppm butane at 200 °C. What’s more, the sensor also exhibited good short- and long-term stability, repeatability and selectivity, which made it a potential candidate in the application of monitoring butane. In the end, the possible mechanisms of gas-sensing properties were discussed. [ABSTRACT FROM AUTHOR]

Light‐emitting diode (LED)‐driven displays create colored images by down‐converting an intense blue LED signal to longer wavelengths using inorganic phosphors. Unfortunately, overexposure to this blue LED emission throughout the course of a day has been linked to insomnia and mood disorders. “Human‐centric” lighting can alleviate this problem by transitioning to safe violet LED driven devices and utilizing a trichromatic phosphor mixture. For further details see article number 2202689 by Jakoah Brgoch and co‐workers. [ABSTRACT FROM AUTHOR]

Ab initio calculations, human-centric lighting, melatonin suppression, phosphorous oxynitride, violet-excitation "Human-centric" lighting can alleviate this problem by transitioning to safe violet LED driven devices and utilizing a trichromatic phosphor mixture. Keywords: ab initio calculations; human-centric lighting; melatonin suppression; phosphorous oxynitride; violet-excitation EN ab initio calculations human-centric lighting melatonin suppression phosphorous oxynitride violet-excitation 1 1 1 04/20/23 20230415 NES 230415 Light-emitting diode (LED)-driven displays create colored images by down-converting an intense blue LED signal to longer wavelengths using inorganic phosphors. [Extracted from the article]

In this paper, a convenient solution combustion method to synthesis hierarchically porous Ag-loaded ZnO heterojunction nanocomposites with various Ag contents was reported. The analysis of X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and Brunauer-Emmett-Teller (BET) nitrogen adsorption-desorption were conducted to characterize the ingredients, microstructure and surface morphology. Ag and ZnO show separate phases due to the reduction of Ag + and the faster crystallization rate of ZnO. The as-synthesized powders were used as gas sensing materials to fabricate gas sensors. The gas-sensing performance was tested towards 100 ppm formaldehyde at an optimum operating temperature of 240 °C and Ag-loaded ZnO (with the different Ag atomic ratio) based gas sensors showed a superior gas-sensing performance comparing with pure ZnO. Especially 1 at% Ag-loaded ZnO has the highest gas response as 170.42. The possible gas-sensing mechanism was discussed in this paper. For example, the influence of surface area, the formation of heterostructure, Ag elements, adsorbed oxygen and so on. [ABSTRACT FROM AUTHOR]

A facile, cost-effective, template-free chemical method was developed for the synthesis of β -Co(OH) 2 nanoplatelets under the different preparation conditions. The morphology and microstructure of as-synthesized samples were examined by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray photoelectron spectrum (XPS), respectively. The observations revealed the formation of a single phase of the hexagonal brucite-like β -Co(OH) 2 , which had an irregular hexagonal disk with angles of adjacent edges of 120°, edge lengths ranging from 200 to 300 nm, and thicknesses of 20–40 nm. When investigated as catalyst for CO oxidation, the β -Co(OH) 2 nanoplatelets exhibited good catalytic activity for CO. Among β -Co(OH) 2 nanoplatelets, the sample prepared at 100 °C for 8 h performed the best, giving the T 100% (the temperature required for achieving a CO of 100%) of 120 °C for the oxidation of CO. There are good correlations of Co 3+ /Co 2+ , the absorbed O x − ions and surface OH group with catalytic activity of the samples for CO oxidation. [ABSTRACT FROM AUTHOR]

Macro-/nanoporous Al-doping ZnO powders with enhanced gas sensing properties are prepared by a solution combustion method using Zn(CH 3 COO) 2 ·2H 2 O, Zn(NO 3 ) 2 ·6H 2 O, Al(NO 3 ) 3 ·9H 2 O, N 2 H 4 ·H 2 O and C 2 H 5 NO 2 as precursors. Characterization by TEM, SEM and BET techniques demonstrates that the Al-doping ZnO powders have a coral-like morphology with a hierarchically porous structure from macro pores, with the wall containing smaller mesopores. The gas-sensing characteristics of the ZnO samples with different Al-doping concentrations are investigated and the results indicate that the gas sensor prepared from 2.5 at% Al doping ZnO powders shows the highest gas sensitivity and selectivity towards n -butanol. A maximum gas response of 751.95 towards 100 ppm n -butanol is achieved at the operating temperature of 300 °C. The mechanisms of responses are also proposed considering the unique material structure. [ABSTRACT FROM AUTHOR]

Pure and Al-doped macro-/nanoporous ZnO were synthesized via solution combustion method by using zincacetate dihydrate (Zn(CH 3 COO) 2 ·2H 2 O), zinc nitrate hexahydrate (Zn(NO 3 ) 2 6H 2 O), aluminum nitrate nonahydrate (Al(NO 3 ) 3 ·9H 2 O), hydrazine hydrate (N 2 H 4 ·H 2 O) and glycine (C 2 H 5 NO 2 ) as precursors. The morphology, structure and catalytic properties of the as-synthesized macro-/nanoporous products were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), UV–Vis spectroscopy, Brunauer-Emmett-Teller (BET) nitrogen adsorption-desorption and Fourier transform infrared spectroscopy (FTIR), respectively. Pure and Al-doped ZnO have coral-like shape with the pores size ranging from several nanometers to ten micrometers. The walls of the macropores contain smaller nanopores, exhibiting the hierarchically porous morphology. The catalytic activities of the as-synthesized samples were tested by measuring the degradation efficiency of azo dye Congo red (CR) under visible light, UV light and dark light, respectively. The results show excellent removal capacity for organic pollutants CR in wastewater. Macro-/nanoporous Al-ZnO with different contents of Al have better catalytic degradation efficiency than pure ZnO. The experimental results indicate the potential use of macro-/nanoporous Al-ZnO for catalytic degradation of Congo red dye in different environments, which provides a potentially low-cost alternative for the remediation of azo-dye effluents. [ABSTRACT FROM AUTHOR]

Hollow CuO fibers were successfully fabricated using a facile solution combustion method by incorporating cotton fibers as biotemplate. XRD patterns along with Rietveld refinement confirm the formation of CuO with monoclinic phase. The length of the as-synthesized CuO fibers is at micrometer scale, and the average fiber diameter ranges from several nanometers up to order of micrometers. After combustion reaction, a large amount of coalescent particles left on the surface of the cotton fibers to form porous walls of CuO. By totally removing cotton body at 600 °C, hollow CuO fibers were obtained. A possible growth mechanism of hollow CuO fibers using cotton fibers as templates was given based on experimental data. When used as a sensing material in gas sensor, it exhibited a superior sensitivity and good selectivity toward low-ppm-level (1–100 ppm) n -propanol. Theses findings not only provide a novel approach to fabricate hollow CuO fibers via a solution combustion route, but also explore a promising gas sensor toward n -propanol. [ABSTRACT FROM AUTHOR]

Pyrolysis is an effective way for the sludge harmless, reduction treatment and resource utilization. In this study, the pyrolysis kinetics and thermodynamics of PTA sludge was evaluated. Afterword, a cyclic in-situ catalytic pyrolysis of PTA sludge by using recycled char as a catalyst was conducted. The product characterization, e.g. pyrolysis syngas as well as the catalytic effect of pyrolysis char, were analyzed. The results demonstrated that the Kissinger-Akahira-Sunose (KAS), Ozawa-Flynn-Wall (OFW), and Starink model-free methods have good agreement on kinetic parameters, the average activation energy was calculated at 295.18, 286.62, and 290.55 kJ/mol, respectively. Meanwhile, thermodynamic parameters, e.g. the variations in enthalpy (Δ H), entropy (Δ S), and Gibbs free energy (Δ G), were evaluated based on the deduced kinetic results, whereby the suitable pyrolysis temperature was determined at 973 K. The results of cyclic in-situ catalytic pyrolysis showed that the pyrolysis char could promote tar cracking, which greatly increased the yield of pyrolysis syngas. After five rounds of in-situ catalytic pyrolysis, the yield of pyrolysis syngas increased from 0.089 L/g to 0.176 L/g and the carbon conversion increased from 24.8% to 36.5%, respectively. • A cyclic in-situ catalytic pyrolysis with recycled char as a catalyst was proposed. • The pyrolysis kinetics and thermodynamics of PTA sludge were evaluated. • The carbon conversion was increased to 36.5% by five rounds of in-situ pyrolysis. • The char has effects on improving the yield of syngas by promoting cracking of tar. [ABSTRACT FROM AUTHOR]

One dimensional Mn–Ce–O x composite nanomaterials with various Mn contents were synthesized successfully by a hydrothermal method. The impacts of Mn contents on their morphologies and physical properties were investigated by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). The analysis reveals that the obtained composites are one-dimensional (1D) rod-like nanostructures. The catalytic behaviors of Mn–Ce–O x nanomaterials were investigated for CO oxidation. The Mn–Ce–O x catalysts were found to be more active than catalysts based on ceria alone. The catalytic activities of all one dimensional Mn–Ce–O x materials for CO conversion are quite high (142< T 50% <229 °C). Among the obtained nanocatalysts, the Mn–Ce–O x composite nanomaterials with 40 wt% Mn exhibit the best catalytic activity and the 50% CO conversion can be reached at 142 °C. The presence of transition metal element Mn can promote the production of oxygen vacancies and improve oxygen mobility, which result in enhancing the oxygen-storage capacity of the one dimensional Mn–Ce–O x materials and its catalytic performance for CO conversion. [ABSTRACT FROM AUTHOR]

ZnO quantum dots (QDs), a few nanometers in size, were synthesized by a sol–gel method using different solvents (methanol, ethanol and hexanol). The structural, morphological and photoluminescent properties were investigated by X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), photoluminescence spectrometry, and UV-vis spectroscopy. The results indicated that ZnO QDs with good dispersion, ranging in size from 3.3 nm to 7.7 nm, could be controlled easily by the solvents. The ZnO QDs exhibited strong visible emission from green to orange. The reasons for the change in emission color are believed to be the quantum size effect and the change in defect concentration due to the different solvents used in their preparation. A possible mechanism for the photoluminescence of ZnO QDs is also presented. [ABSTRACT FROM AUTHOR]

The photo‐rechargeable supercapacitor enables the self‐powering of flexible wearable electronics. However, flexible wearable electronics require supercapacitors not only with excellent flexibility but also with high energy density. P‐diaminoazobenzene (P‐Azo) as a new type of organic electrode material with NN is directly connected to the benzene ring and forms a large π‐conjugated system, which makes it have a lower lowest unoccupied molecular orbital (LUMO) energy level, is beneficial to transfer of electrons, and increases the conductivity of organic molecules. In addition, NN can realize the transfer of two electrons, which makes P‐Azo have a higher energy density. Asymmetric flexible supercapacitors are fabricated by assembling P‐Azo, activated carbon, and an adhesive electrolyte, with 425.2 mW h cm−2 (55.19 Wh kg−1) energy density at a power density of 80 mW cm−2 (10.38 W kg−1), and 90.7% capacitance retention after 80 000 cycles of bending. In this work, supercapacitors and perovskite submodules are coupled to prepare a photo‐rechargeable supercapacitor to achieve a 7% overall energy‐conversion efficiency. Therefore, this supercapacitor paves a practical route for powering future wearable electronics. [ABSTRACT FROM AUTHOR]

• Chemical looping gasification of pine sawdust by Fe 2 O 3 -rich sludge ash was studied. • Thermal behaviors and gasification performance were analyzed by TGA and DCLG tests. • Interactions between pine sawdust and sludge ash exist, are related to blending ratio. • SA presence and high ratio promote the conversion of PS, but reduce DCLG performance. • DCLG reactivity was improved as the temperature rose, and kept stable for multiples. The thermal characteristics and kinetic parameters of direct chemical looping gasification (DCLG) of pine sawdust (PS) were researched using a TGA at a well-defined heating rate. The three-phase product yields, syngas contents, DCLG performances, and multiple reactions were analyzed by a DCLG evaluation apparatus coupled with a gas chromatography (GC). TGA results indicated that, as the SA blending ratio was at 10%, the interactions between PS and SA mainly occurred at lower temperatures, while with the SA ratio increasing, more interactions also happened at the higher temperatures. The kinetics analysis results indicated that the activation energies of the first thermal decomposition zone of PS were independent with the SA ratios, while the values of the second and third zone were related to them. Through DCLG evaluation experiments, it was found that the SA presence, and the increase in SA ratios would promote the conversion of PS, while decrease the gasification performance. As the gasification temperature increased, the DCLG performance of PS would be improved, but the highest heating value of syngas produced would be obtained at 750 °C. The multiple DCLG experiments showed that the reaction performance of Fe 2 O 3 -rich sludge ash as an oxygen carrier could almost keep stable. The research results of this paper could give some useful guides for the potential application of Fe 2 O 3 -rich sludge ash as an oxygen carrier in direct chemical looping gasification of biomass feedstock. [ABSTRACT FROM AUTHOR]

• The high-temperature gasification and melting properties of PRPS were studied. • The PRPS prepared at 650 °C shows the best gasification reactivity. • The high-yield effective gas (CO + H 2) was found in the N 2 /CO 2 atmosphere. • The high-density of slag and reduction of PRPS was obtained in the N 2 /CO 2 atmosphere. High-temperature gasification and melting is a promising technology for the harmless disposal and resource utilization of hazardous organic solid wastes. In this study, the high-temperature gasification and melting properties of pyrolysis residues from petrochemical sludge (PRPS) were experimentally investigated. Firstly, the PRPSs in pyrolysis temperatures of 500–700 °C were prepared. The gasification reactivity of PRPSs was investigated through micropolitics pore structure and Raman spectrum analysis. The results show that the PRPS prepared at 650 °C has the best gasification reactivity, with both large surface area and more complete porous structure, and more disordered carbon microstructures. Then, based on the PRPS sample prepared at 650 °C, the effects of the gasification temperature (1100–1400 °C) and atmosphere (N 2 , H 2 O, and CO 2) were studied. In the atmosphere of 40 vol.%N 2 /30 vol.%CO 2 /30 vol.%H 2 O, the yield of effective gas (CO+H 2) began to decrease when the temperature was above 1200 °C. With the increase of temperature (1300–1400 °C), high-density slag of PRPS was observed. At the temperature of 1400 °C, the highest yield of effective gas (CO+H 2), the high-density slag, and the reduction of PRPS were obtained in the atmosphere of 40 vol.%N 2 /60 vol.%CO 2. In this condition, the high CO is conducive to form FeO as fluxing. Moreover, the stable mineral phases (CaSiO 3 , CaSi 2 O 7 , etc.) were detected, which should perform a good solidification effect of heavy metals in the slag. [ABSTRACT FROM AUTHOR]

Photorechargeable supercapacitors are perfect energy storage devices, particularly for solar cells that output electricity only during sunshine hours. The lower energy density of supercapacitors is due to fewer redox‐active sites, poor electrolyte accessibility at the electrodes, and charge loss during charge transfer from solar cells to the supercapacitor. Here, an electrolyte‐accessible organic–inorganic hybrid electrode with synergistic pseudocapacitance of Ti3C2Tx and high theoretical specific capacity CO active centers to enhance the energy density of the supercapacitor is proposed. Density functional theory (DFT) calculations show that the covalent cross‐linking of organic molecules changes the charge density redistribution of Ti3C2Tx, enhances ion absorption and storage, and increases the energy density of the supercapacitors. Based on these DFT calculation results, hybrid electrodes are successfully prepared using p‐phenylene diisocyanate to covalently cross‐link pseudocapacitors Ti3C2Tx with anthraquinone such as 1‐hydroxyanthraquinone (HA) or 1‐amino‐4‐bromoanthraquinone‐2‐sodium sulfonate (ABS). The Ti3C2Tx‐HA hybrid electrodes exhibit high areal specific capacity (2532.5 mF cm−2), excellent ion absorption storage capability, and long‐term stability. The asymmetric supercapacitor yields a decent area specific capacity (1686.72 mF cm−2 at 0.25 mA cm−2) and energy density (599.72 mWh cm−2 at a power density of 200 mW cm−2). These high‐energy‐density supercapacitors are coupled with perovskite solar cells to prepare photorechargeable supercapacitors with fast energy storage. [ABSTRACT FROM AUTHOR]

Copper, as an essential element in human body, can have adverse impact on environment and healthy individuals if it is excessive. So it is necessary to establish a rapid and effective method for detecting Cu2+. In this work, we describe a method for determination of Cu2+ based on water-soluble ZnO quantum dots (QDs) modified with (3-aminopropyl)triethoxysilane (APTEs). The ZnO QDs functionalized with APTEs (NH 2 –ZnO QDs) synthesized by a simple sol-gel method and displayed strong yellow-green fluorescence with a peak at 535 nm under 350 nm excitation. High-resolution transmission electron microscopy, Fourier transform infrared spectroscopy, luminescence, and UV–visible absorption spectroscopy were used to characterize the NH 2 –ZnO QDs. In addition, the emission from NH 2 –ZnO QDs was selectively quenched upon addition of Cu2+. Therefore, this finding was used to design a fluorescent probe based on NH 2 –ZnO QDs to detect Cu2+ in water solution, and the linear relationships were 2–20 nM and 1–100 μM respectively, with detection limit for Cu2+ at 1.72 nM (on the basis of 3σ/slope criterion). This fluorescent probe had also been applied in real water sample to testify its availability in drinking water. Furthermore, the quenching mechanism was studied by measurements of UV–visible absorption spectra and fluorescent lifetime of ZnO QDs, which may be attributed to the aggregation induced by Cu2+ and the dynamic quenching existing energy transfer between QDs and Cu2+. (3-aminopropyl)triethoxysilane modified water-soluble ZnO quantum dots synthesized by simple sol-gel method exhibit the excellently selective and sensitive fluorometric determination to Cu2+. Image 1 • Water-soluble NH 2 –ZnO QDs were synthesized by facile hydrothermal method. • Fluorometric determination of Cu2+ shows higher sensitivity and wider detection limitation. • Quenching mechanism associates to the coordination interaction between NH 2 –ZnO QDs and Cu2+. • NH 2 –ZnO QDs will be also helpful for the design of fluorometric determination of Cu2+. [ABSTRACT FROM AUTHOR]

• A highly selective ratiometric fluorescent sensor N-CQDs/AuNCs for carbendaizm was developed. • The sensor has good selectivity and sensitivity to carbendazim with wide dynamic response range. • Sensor avoids the influences caused by probe concentration and drifts of optoelectronic system. • The ratiometric fluorescent sensor is a promising candidate for carbendazim detection. A novel fluorescence "turn on" ratiometric fluorescent sensor was employed to determine carbendazim. The sensing process was achieved through the strong fluorescence resonance energy transfer (FRET) between nitrogen doped carbon quantum dots (N-CQDs) and gold nanocluster (AuNCs). The photoluminescence intensity of N-CQDs can be deactivated by AuNCs through FRET effect and recovered by the addition of carbendazim. The ratiometric detection of carbendazim is achieved by recording the photoluminescence and second-order Rayleigh scattering (SRS) signal of N-CQDs/AuNCs system. With the introduction of carbendazim to the sensing platform resulted in the photoluminescence and SRS signal of N-CQDS/AuNCs enhancing. UV–vis absorption, Zeta potential and fluorescence lifetime analyses indicate that the fluorescence turn on process can be attributed to the aggregation of AuNCs breaks the FRET process and increases SRS intensity. N-CQDs/AuNCs probe present a good sensitivity and selectivity for carbendazim detection, with two linear response ranges (1−100 μM, 150−1000 μM), low detection limit of 0.83 μM and 37.25 μM. Furthermore, real sample analyses indicate that the as-presented sensor has potentials in carbendazim determination in real sample analyses. [ABSTRACT FROM AUTHOR]

• Duplex S-N curve associated with surface and subsurface failures under R = 0 is more obvious. • Deflection of crack surfaces contributes to the slow crack growth especially in the FCA. • Subsurface failure mechanism with the determination of stress intensity factors is elucidated. • An energy-based life prediction approach with crack nucleation and growth is proposed. Fully reversed and pulsating tension fatigue tests were performed to clarify the subsurface failure behavior of TC11 titanium alloy in high-cycle and very-high-cycle regimes. The deflection of crack surfaces induces the premature contact of crack surfaces and slow crack growth. The whole failure processes mainly include: (i) nucleation of microcracks, (ii) coalescence and growth of microcracks, (iii) formation of facet cluster area, (iv) early macrocrack growth, (v) formation of fisheye, (vi) unstable macrocrack growth and (vii) momentary fracture. Based on the modeling of crack nucleation and growth, an energy-based approach is well proposed to predict the total fatigue life. [ABSTRACT FROM AUTHOR]

Although both protein arginine methylation (PRMT) and jasmonate (JA) signaling are crucial for regulating plant development, the relationship between these processes in the control of spikelet development remains unclear. In this study, we used the CRISPR/Cas9 technology to generate two OsPRMT6a loss-of-function mutants that exhibit various abnormal spikelet structures. Interestingly, we found that OsPRMT6a can methylate arginine residues in JA signal repressors OsJAZ1 and OsJAZ7. We showed that arginine methylation of OsJAZ1 enhances the binding affinity of OsJAZ1 with the JA receptors OsCOI1a and OsCOI1b in the presence of JAs, thereby promoting the ubiquitination of OsJAZ1 by the SCFOsCOI1a/OsCOI1b complex and degradation via the 26S proteasome. This process ultimately releases OsMYC2, a core transcriptional regulator in the JA signaling pathway, to activate or repress JA-responsive genes, thereby maintaining normal plant (spikelet) development. However, in the osprmt6a-1 mutant, reduced arginine methylation of OsJAZ1 impaires the interaction between OsJAZ1 and OsCOI1a/OsCOI1b in the presence of JAs. As a result, OsJAZ1 proteins become more stable, repressing JA responses, thus causing the formation of abnormal spikelet structures. Moreover, we discovered that JA signaling reduces the OsPRMT6a mRNA level in an OsMYC2-dependent manner, thereby establishing a negative feedback loop to balance JA signaling. We further found that OsPRMT6a-mediated arginine methylation of OsJAZ1 likely serves as a switch to tune JA signaling to maintain normal spikelet development under harsh environmental conditions such as high temperatures. Collectively, our study establishes a direct molecular link between arginine methylation and JA signaling in rice. This study shows that arginine methylation of OsJAZ1 by OsPRMT6a enhances its binding affinity with OsCOI1a/OsCOI1b, thus promoting the ubiquitination and degradation of OsJAZ1 and, ultimately, jasmonate (JA) responses. In the osprmt6a-1 mutant, the absence of OsJAZ1 arginine methylation results in stabilization of OsJAZ1 proteins, thus repressing JA responses and ultimately leading to abnormal spikelet structures. In addition, JA signaling reduces the OsPRMT6a mRNA level, establishing a negative feedback loop to balance JA signaling. [ABSTRACT FROM AUTHOR]

Ultra-long life fatigue tests of 106-109 cycles under asymmetrical loading were conducted to elucidate the subsurface facets-induced crack nucleation behavior of two alpha-beta titanium alloys, and a theoretical method of describing the microstructure-based strength relationship was proposed. As a result, two titanium alloys all present the continuously descending S – N (stress - number of cycles) curve characteristics with subsurface non-defect induced failure. A bright convergence zone with facets becomes the remarkable feature of failure. By means of the milling of focused ion beam system, the coalescence and growth of subsurface micro-cracks crossing several grains along the 45° angle, controlled by the maximum shear stress, can be observable. Based on this, a subsurface facets-induced crack nucleation and growth mechanisms for titanium alloys was proposed in combination with the discussion of small crack fracture mechanics. In view of the good consistency between the evaluated nucleation life of crack at the size of convergence zone with facets and the total life, the microstructure-based modelling method for evaluating fatigue strength of titanium alloys with subsurface failure in ultra-long life regime can be acceptable. [ABSTRACT FROM AUTHOR]

Thioglycolic acid-functionalized ZnSe quantum dots (QDs) as a colorimetric nanoprobe were prepared and applied to the determination of cobalt(II) and iron(III). Test strips were obtained by a dipping-drying process. On exposure to Co(II), they undergo a color change from white to brown, and on exposure to Fe(III) from white to pink. The limits of detection (LOD) are 2.6 mg L−1 for Co(II) and 2.2 mg L−1 for Fe(III). Test strips introduce a low-cost, portable, rapid and convenient tool for determination of Co(II) and Fe(III). In addition, two other analytical methods have been studied for detection of Co(II) and Fe(III) at low concentration. The first is UV-vis spectrometry which has a LOD as low as 0.14 mg L−1 for Co(II) (at 412 nm) and 0.12 mg L−1 for Fe(III) (at 400 nm). The second is dynamic light scattering (DLS) with a LOD of 3.0 μg L−1 for Co(II) and 2.5 μg L−1 for Fe(III). [ABSTRACT FROM AUTHOR]

Abstract Water-soluble rhodamine B assisted graphene quantum dots (RhB-GQDs) were synthesized by a facile one-pot hydrothermal method, using rhodamine B and ethylenediamine as nitrogen source. The as-synthesized RhB-GQDs have few layers configuration with an average size of 4.5 nm and good distribution. The fluorescence quenching approach was applied to the sensing of mercury ions in water. Rodamine B absorb on the surface of RhB-GQDs, and it can prevent RhB-GQDs from contacting with interfering cations. The presence of N atoms reduces the ability of interfering cations to form stable complex with carboxyl groups, and gives the RhB-GQDs good selectivity to mercury ions. In the case of low concentration, the fluorescence quenching efficiency of as-synthesized RhB-GQDs still has a good liner relationship with concentration. Due to the strong affinity of Hg2+ to amino and carboxyl on the surface of RhB-GQDs, the fluorescence of RhB-GQDs is quenched by nonradiative electron transfer between Hg2+ and the excited state of RhB-GQDs. Based on the fluorescence turn off process, the as-synthesized RhB-GQDs can be served as fluorescent platform for the sensitive and selective detection of Hg2+ with a detection limit of 0.16 nM. Graphical abstract Rhodamine B assisted graphene quantum dots (RhB-GQDs) synthesized a facile one-pot hydrothermal method using rhodamine B and ethylenediamine as nitrogen source exhibit the excellently selective and sensitive response to Hg2+ as flourescent sensor. fx1 [ABSTRACT FROM AUTHOR]

To understand the potential effects of intrinsic calcium compounds on sludge pyrolysis, the pyrolysis behavior of petrochemical sludge (PS), calcium carbonate blend PS (CaPS), and decalcified PS (DePS) were investigated using thermogravimetric analysis (TGA) and in-situ Fourier-transform infrared spectroscopy coupled with pyrolysis-gas chromatography and mass spectrometry (Py–GC/MS). The TGA results indicated that decalcification increased and decreased the energy barriers of PS decomposition in ranges 200–350 °C and 350–600 °C, respectively. In contrast, copyrolysis with CaCO 3 decreased the activation energy (E) of the pseudoreaction phase 2 (PH2) and altered the mechanism model. Meanwhile, during copyrolysis, char deposition and interaction hindered CaCO 3 decomposition. The two-dimensional correlation spectroscopy results, on the other hand, showed that the reaction priority of O-containing groups and CH– vibration of methyl groups were affected by both decalcification and CaCO 3 copyrolysis. The Py–GC/MS results indicated that the three sludges mainly released hydrocarbons, N-containing organics, alcohols, aldehydes, and acids. During pyrolysis, CaCO 3 also played a neutralization role, which reduced the release of pyrolytic acidic products. In addition, the increase of the pyrolysis temperature increased the hydrocarbon content. This research will guide the industrial application of sludge pyrolysis. [Display omitted] • Roles of intrinsic Ca compound on pyrolysis of petrochemical sludge were studied. • Decalcification increased decomposition energy barrier at low-temperature pyrolysis. • Decalcification and co-pyrolysis with CaCO 3 altered the order of char devolatilization. • Co-pyrolysis with CaCO 3 affected O-containing and methyl groups evolution. • Co-pyrolysis with DePS increased E of CaCO 3 decomposition stage by 78.4 kJ/mol. [ABSTRACT FROM AUTHOR]

SnO 2 is a typical metal oxide semiconductor gas sensitive material, which has been studied deeply. However, pure SnO 2 sensing materials usually have good performance at high operating temperatures. In this study, we reported an n-butanol sensor with high selectivity and fast response based on SnO 2 submicron porous cube prepared by heating and decomposing the Sn-based metal-organic framework material (Sn-MOF) in air at a certain temperature. SnO 2 submicron porous cube prepared at 450 °C shows good response and selectivity for n-butanol. And it has a response (%) of 175% to 100 ppm n-butanol and a relatively fast response/recovery time of 184 s/183 s at room temperature. The (110) crystal plane with sufficient oxygen-rich vacancy can adsorb O 2 and n-butanol molecules more effectively. Therefore, its sensitivity to n-butanol gas can be significantly improved. This work provides a good idea for further research on pure metal oxide semiconductor room temperature gas sensors. [ABSTRACT FROM AUTHOR]

This paper describes the preparation with a sol-gel method as well as formaldehyde (HCHO) gas sensing properties of CdIn 2 O 4 nanoporous thin film. CdIn 2 O 4 nanoporous thin film was prepared using poly(ethylene- co -butylene)- b -poly(ethylene oxide) diblock copolymers as template. The film was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscope (AFM), and x-ray photoelectron spectroscopy (XPS), respectively. The analyzed results indicate that the obtained thin film is highly crystalline and has pore-solid architectures after removal of the polymer template by calcination. As-prepared CdIn 2 O 4 nanoporous thin film was used directly as sensing device to investigate the sensing properties in HCHO atmosphere. The home-built CdIn 2 O 4 nanoporous thin film gas-sensor shows high response, selectivity, and long-time stability toward HCHO gas at low operating temperature (100 °C), making the thin film not only interesting for sensor devices, but also for a number of related electrochemical applications. [ABSTRACT FROM AUTHOR]

This work uses ZnO nanoparticles as the probe and a case, proving that the grey level can replace fluorescent intensity to realize a quantitative detection function of paper-based Cu 2+ sensor. Portable Cu 2+ test papers were obtained through dipping filter papers in as-prepared ZnO sol possessing the Cu 2+ quenching property. Based on grey level which is obtained through ordinary digital camera and computer, the detection function of the fabricated Cu 2+ test paper is extended from qualitative detection relied on naked eyes to quantitative detection whose detection range is calculated to be 10–1000 μM. The fabricated test papers also could resist the interruption of some competing ions and is a potential candidate for portable Cu 2+ detection device with quantitative function. Since the strategy of replacing fluorescence intensity by grey level is based on the map relationship between the fluorescence intensity and the digital signal (grey level), it is promising to be applied to other fluorescent test papers to gain quantitative test papers aimed at corresponding chemicals. At the same time, the mechanism of Cu 2+ -induced fluorescence quenching was also investigated by fluorescence lifetime, UV–vis spectra, and photoluminescence spectra. And a static quenching mechanism based on the non-fluorescence complex formed by Cu 2+ and O x − is brought up. [ABSTRACT FROM AUTHOR]

ZnO hollow spheres with high crystallinity were prepared successfully via a simple template process using ZnCl 2 , carbamide and polystyrene spheres (PSS) as raw materials. The structural and morphological characterizations of the samples were carried out by X-ray diffraction (XRD), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS), respectively. Indirect-heating sensor using ZnO hollow spheres as sensing materials was fabricated on an alumina tube with Au electrodes and Pt wires. The gas sensing properties of the as-synthesized ZnO hollow spheres for n -butanol were investigated. It is shown that the sensor exhibited good sensing performances, characterized by high response, very short response time, and stability to n -butanol gas at operating temperature of 385 °C. These results indicate that the ZnO hollow spheres are highly promising candidates for practical detectors for n -butanol. [ABSTRACT FROM AUTHOR]

As a new methanol sensing material, the composite of palladium-platinum-In 2 O 3 composited nanocrystalline SnO 2 was successfully obtained by a solid-phase reaction method. The phase composition and the unique structure of as-prepared SnO 2 -Pd-Pt-In 2 O 3 composite were comprehensively characterized using the techniques such as X-ray powder diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM), respectively. The results of gas sensing properties indicate that the sensor based on the as-prepared SnO 2 -Pd-Pt-In 2 O 3 composite shows the ultra-high response to methanol at an optimal operating temperature of 160 °C when the mass ratio of SnO 2 , Pd, Pt and In 2 O 3 is 100:0.8:2:30. The gas response toward 100 ppm of methanol reaches as high as 320.73. The detection limit of the sensor is estimated to be 0.1 ppm. The sensor also exhibited good response-recovery properties, selectivity, remarkable repeatability and stability, suggesting its greatly promising application in gas sensing. This work could stimulate an effective means to fabricate methanol sensor with superior performance. At the same time, a possible sensing mechanism of the SnO 2 -Pd-Pt-In 2 O 3 composite is discussed. [ABSTRACT FROM AUTHOR]

The discovery of photoacoustic laser streaming has opened up a new avenue to manipulate and drive fluids with light, but the necessity of an in situ "launch pad" has limited its utility in real‐world microfluidic applications due to both the size constraint and the complexity of fabrication. Here, it is demonstrated that 1) a versatile microfluidic pump can be materialized by using laser streaming from an optical fiber, and 2) laser streaming can be generated from a flat metal surface without any fabrication process. In the latter case, by focusing laser on the tip of a sewing needle tip, the needle can be turned into a micropump with controllable flow direction. Additionally, high‐speed imaging of the fluid motion and computational fluid dynamics simulations to confirm the photoacoustic principle of laser streaming are employed, and it is revealed that the streaming direction is determined by the direction of strongest intensity in the divergent ultrasound wavefront. Finally, the potential of laser streaming for microfluidic and optofluidic applications is demonstrated by successfully driving fluid inside a capillary tube. [ABSTRACT FROM AUTHOR]

Strigolactones (SLs) constitute a class of plant hormones that regulate many aspects of plant development, including repressing tillering in rice (Oryza sativa). However, how SL pathways are regulated is still poorly understood. Here, we describe a rice mutant dwarf and high tillering1 (dht1), which exhibits pleiotropic phenotypes (such as dwarfism and increased tiller numbers) similar to those of mutants defective in SL signaling. We show that DHT1 encodes a monocotyledon-specific hnRNP-like protein that acts as a previously unrecognized intron splicing factor for many precursor mRNAs (pre-mRNAs), including for the SL receptor gene D14. We find that the dht1 (DHT1I232F) mutant protein is impaired in its stability and RNA binding activity, causing defective splicing of D14 pre-mRNA and reduced D14 expression, and consequently leading to the SL signaling-defective phenotypes. Overall, our findings deepen our understanding of the functional diversification of hnRNP-like proteins and establish a connection between posttranscriptional splicing and SL signaling in the regulation of plant development. [ABSTRACT FROM AUTHOR]

Three-dimensional macro/mesoporous tricobalt tetraoxide Co 3 O 4 was prepared via a facile self-sustained decomposition using the complexes of metallic salts and organics (metal–organic complexes). Porous Co 3 O 4 material was characterized using X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopy, and X-ray photoelectron spectrum (XPS) to examine the morphology and microstructure to find out the cause. Co 3 O 4 with the 3D hierarchical porous structure consisting of nanoparticles has a coral-like shape with a size of tens of micrometers and exhibits the hierarchically porous morphology, in which the walls of the macropores contain smaller mesopores. The catalytic performance of the porous Co 3 O 4 for CO oxidation has been studied with a continuous flow fixed-bed quartz microreactor. The porous Co 3 O 4 exhibits excellent catalytic activity for CO oxidation, the CO conversion rate reaches 100% at 140 °C. [ABSTRACT FROM AUTHOR]

• Electrostatic anchoring in situ polymerization synthesizes hybrid electrode materials. • MXene collaboratively with high Th loading enhances specific capacity and cycle stability. • Combining supercapacitors with perovskite solar cells achieves rapid charge storage. Portable photorechargeable supercapacitors hold great promise as ideal power sources for future IoT applications. However, the widespread implementation of supercapacitors is hindered by their suboptimal energy density. Organic electrodes, with their high specific capacity, have become rising stars in the energy storage community. Herein, we pioneer an electrostatic-anchoring in situ polymerization reaction pathway to synthesize MXene-organic hybrid electrode materials. Theoretical calculations show that thionine (Th) is the optimal candidate for grafting onto the pseudocapacitive 2D MXene due to its low energy levels, narrow band gap, and multiple active sites. Multilevel interactions between Th and MXene are established to prevent Th from dissolution, to inhibit the MXene from restacking, and to facilitate electron accumulation in Th, thus enhancing the accessibility/absorption of ions in electrolytes and electrode stability. The hybrid electrodes exhibit a specific capacity as high as 4906.7 mF/cm2 at 1 mA cm−2; more importantly, an integrated asymmetric flexible supercapacitor displays high specific capacity (3183.1 mF/cm2) and large energy density (1432.4 mWh/cm2), all three values are the highest among their respective categories. Combining supercapacitors with all-inorganic perovskite solar cells to achieve rapid charge storage. [ABSTRACT FROM AUTHOR]

Abstract Co(OH) 2 @FeCo 2 O 4 nanocomposite was successfully synthesized via a facile one-step hydrothermal reaction without thermal treatment. The structure and chemical composition of as-synthesized Co(OH) 2 @FeCo 2 O 4 was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS), respectively. The results show the FeCo 2 O 4 nanosheets are covered with the Co(OH) 2 nanoparticles and the BET show the nanocomposite possess the mesoporous structure with specific surface area and total pore volume are 93.071 m2 g−1 and 0.37 cm3 g−1, respectively. In addition, the electrochemical performances were investigated in a three-electrode system to evaluate the material. The as-synthesized Co(OH) 2 @FeCo 2 O 4 nanocomposite exhibits a high specific capacitance of 1173.43 F g−1 at 1 A g−1 and remarkable cycling stability with 95.4% capacitance retention after 5000 cycles. The results show the higher capacitance and longer cycle performance, compared with the Co(OH) 2 and FeCo 2 O 4 , respectively. This remarkable electrochemical performances were mainly due to mesoporous structure and the synergistic effect of Co(OH) 2 and FeCo 2 O 4. It means that this nanostructure Co(OH) 2 @FeCo 2 O 4 synthesized by this simple and cost-effective method would have more hopeful prospects in energy storage applications. Graphical abstract Co(OH) 2 @FeCo 2 O 4 nanocomposite applied as electrode of supercapacitor shows an impressive enhancement of the performance including the areal capacitance and cycling stability. Image 1 [ABSTRACT FROM AUTHOR]

Highlights • The rougher morphology of FGA reveals the rather distorted crack growth path. • A fatigue strength evaluation model is developed. • The predicted crack growth rate reflects the discontinuous crack growth behavior. • An assessment method is proposed for predicting allowable fatigue strength. Abstract A fatigue assessment approach for interior inclusion-FGA (fine granular area)-fisheye induced fracture was proposed through experimental investigation of very high cycle fatigue properties of two high-strength low-alloy steels. The rougher morphology of FGA reveals the rather distorted crack growth path and slow crack growth rate. A strength evaluation model related to defect size and fatigue life was developed, using which the predicted results are in agreement with the experimental results. Based on the modelling of micro-crack growth rate, the evaluated value can be less than the magnitude of one Burger's vector, which reflects the discontinuous crack growth behavior within FGA. [ABSTRACT FROM AUTHOR]

The raspberry-like SnO 2 hollow nanostructure was synthesized by a simple hydrothermal method. The composition, microstructure, morphology, surface area and chemical states are investigated by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), N 2 adsorption-desorption and X-ray photoelectron spectroscopy (XPS), respectively. The characterization results show that the raspberry-like SnO 2 with a diameter of about 60 nm is composed of numerous SnO 2 nanoparticles with grain size about 8 nm. The raspberry-like SnO 2 was used as sensing material for gas sensor to detect n-butanol gas. The gas-sensing properties including gas response, selectivity, response-recovery time, repeatability, stability and dynamic response character were investigated carefully. It can be found that the response value of the sensor towards 100 ppm n-butanol gas was 303.49 at the low operating temperature of 160 °C. And the detection limit as low as 1 ppm. All results demonstrate the potential of using raspberry-like SnO 2 for n-butanol gas detection. At the same time, the possible formation mechanism and gas-sensing mechanism were also discussed. [ABSTRACT FROM AUTHOR]

ZnO nanocrystalline with a few nanometers in size were synthesized by a low-temperature solvothermal method from zinc acetate dihydrate (Zn(CH 3 COO) 2 ·2H 2 O), potassium hydroxide (KOH) and ethanol (C 2 H 5 OH). X ray diffraction (XRD), transmission electron microscopy (TEM) and X ray photoelectron spectroscopy (XPS) were used to characterize the structure, morphology, specific surface area and chemical state of the samples. The analyzed results indicate that the ZnO nanocrystalline with good dispersion are several nanometers in size about 10 nm. The ZnO nanocrystalline was used as sensing material to fabricate an indirect-heating structure sensor and its gas sensing properties are tested. At the optimal operating temperature (340 °C), its gas response toward 500 ppm n-butanol is 148.11 and the response and recovery time are 20 and 8 s, respectively. The test results show that the sensitivity of the as-prepared gas sensor has high selectivity to n-butanol and good response/recovery characteristics, linear response, short-term repeatability, as well as the long-term stability. The experimental results show that the gas sensor based on ZnO nanocrystalline can be used in the detection and real-time monitoring of toxic gases, especially n-butanol gas, which makes it to be highly promising candidate for practical detectors for n-butanol gas. [ABSTRACT FROM AUTHOR]

High cycle fatigue and very high cycle fatigue properties of a surface-carburized CrNi steel were examined under axial loading with stress ratios of −1 and 0. The positive stress ratio overcomes the effect of carburized layer and promotes crack initiation from the carburized layer. The morphology of fine granular area (FGA) is more distinct under the negative stress ratio with more obvious crack closure effect. Two models concerning the inclusion-fisheye failure and the inclusion-FGA-fisheye failure are proposed. The predicted fatigue lives based on the concept of crack initiation are in good agreement with experimental results. [ABSTRACT FROM AUTHOR]

Cobalt ion (Co 2+ ) is known to be harmful for human beings, and effectively portable sensor is one of the key for its prophylaxis and treatment. In this work, Zn(CH 3 COO) 2 ·2H 2 O, Na 2 S·9H 2 O and thioglycolic acid were used to prepare ZnS quantum dots through a facile water-bath method. The structure and morphology of the ZnS quantum dots were investigated by X-ray diffraction (XRD) and transmission electron microscopy (TEM), respectively. Scanning electron microscope (SEM) was also used to observe the surface morphology of the test paper prepared by a simple dipping-drying process. The Co 2+ sensing properties of as-prepared test paper were investigated. And it was found that the color of as-fabricated test paper could change from white to brown within 1 min with addition of Co 2+ aqueous solution, which makes it possible for qualitative detection of Co 2+ through naked eyes. In this mode, a widely detectable range from 10 to 1000 mg L −1 is reached by the test paper. In addition, through measuring the grey level of the test paper by ordinary smart phone and laptop, a semi-quantitative function of the test paper is realized. Moreover, the as-fabricated paper sensor can resist the interference of a serious cations and anions, and suits for a wide pH surrounding from 1.08 to 9.65, which makes it a promising Co 2+ sensor for practical use. In addition, through X-ray diffraction and UV–vis spectra, the sensing properties of as-fabricated test paper are attributed to the chemical reaction between as-prepared ZnS quantum dots and Co 2+ ions. And the formation of CoS 2 should be responsible for the color change from white to brown. [ABSTRACT FROM AUTHOR]

Zinc oxide nanoparticles with the different Cd doping contents were prepared by with a surfactant-mediated method in this paper. The effects of Cd doping on the gas sensing properties of the ZnO nanoparticles were studied. The morphology and microstructure of as-prepared samples were characterized by X-ray diffraction (XRD); scanning electron microscopy (SEM), transmission electron microscopy (TEM), and high-resolution TEM (HRTEM), respectively. The results reveal that all the products are the high crystalline hexagonal wurtzite ZnO crystal structure. The gas-sensing characteristics of the Cd doped ZnO nanoparticles for volatile organic compounds (VOCs) were investigated. At its optimal operation temperature of 300 °C, the sensing properties of the Cd doped ZnO nanoparticles for n-butanol gas exhibit a high-performance gas sensing performances including high gas response, good selectivity, response/recovery time, and repeatability as well as stability. Especially, its response reaches 130 for 100 ppm n-butanol of ZnO nanoparticles with 2.5% Cd doping. Those values demonstrate the potential of using as-prepared Cd doped ZnO nanoparticles for n-butanol gas detection, making them to be promising candidates for practical detectors to n-butanol gas. Apart from these, the mechanism related to the advanced properties was also investigated and presented. [ABSTRACT FROM AUTHOR]

SnO 2 -composite Pd nanoparticles (0, 2.5, 7.5, 10 mol% Pd loading) were synthesized via solvothermal method, followed by calcination. The structure, morphology, chemical state and specific surface area of the Pd-SnO 2 composite were analyzed with X-ray powder diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscope (TEM), X-ray photoelectron spectroscopy (XPS), N 2 physisorption, respectively. It is found that the composites consist of large amount of SnO 2 microspheres with average diameters up to hundreds of nanometers, and the microspheres are assembled by numerous nanoparticles with average sizes of about 8 nm. To demonstrate their potential application, gas sensors based on the as-synthesized Pd-SnO 2 composites were fabricated to test their sensing performances. The 10 mol% Pd-SnO 2 composite shows an excellent sensing response towards different concentrations of hydrogen at 200 °C. The highest sensing response is up to 315.34 for 3000 ppm hydrogen with a fast response-recovery time (4 s/10 s), which is over 8 times higher than that of pristine SnO 2 , and the lowest detection limit is down to 10 ppm. More significantly, it presents excellent selectivity and stability for hydrogen. The improved sensing response characteristics of the composite could be attributed to the chemical sensitization and electronic sensitization of Pd catalyst. [ABSTRACT FROM AUTHOR]

Beta-manganese dioxide (β-MnO) microrods were hydrothermally synthesized from ammonium persulfate [(NH)SO] solution using manganese sulfate (MnSO) as reductant at 180 °C for 3 h. The characterizations, including X-ray diffraction, scanning electron microscopy, and transmission electron microscopy, showed that the crystallinity and morphology of the as-synthesized samples were well-defined β-MnO microrods with the diameters of about 100 nm and lengths of about 2-4 μm. To explore the optimal degradation conditions, the as-synthesized β-MnO microrods were employed into the degradation of methyl orange dye solution with the concentration of 20 mg/L in the presence of H with pH values equalling 1.0, 1.5, 2.0, 3.0, 5.0, and 7.0, respectively. The results indicate that the degradation efficiency could reach 98% after 9 min at the pH value of 1.0 or 2.0. Also, the lower the pH value, the higher the degradation efficiency. Based on these experimental results, a proper mechanism of the degradation process of methyl orange is proposed and the rationality of the mechanism is further investigated through the scientific control tests. [ABSTRACT FROM AUTHOR]

3D macro-/nanoporous spinel MCo 2 O 4 (M = Zn, Ni, Cu and Fe) have been successfully fabricated by means of an untemplate and flash synthesis via self-sustained decomposition of metal-organic complexes The effects of the combustion agent to metal nitrate ratio on the combustion behavior, phase and morphology of the products were studied. Pure cobaltites with the hierarchically porous morphology were obtained directly through the combustion of the precursors under fuel-lean conditions in one-step without further heat treatment. The samples were characterized by X-ray diffraction, SEM/TEM imaging, mercury intrusion porosimetry, which indicate that the products possess hierarchical porous structure. A possible forming mechanism was given based on the series of experimental data. [ABSTRACT FROM AUTHOR]

Cerium oxide nanoparticles/multi-wall carbon nanotubes (MWCNTs) composites are synthesized by a facile hydrothermal method without any surfactant or template. The morphology and microstructure of samples are examined by scanning electron microscopy (SEM), transition electron microscopy (TEM), X-ray diffraction (XRD), Raman spectrum and X-ray photoelectron spectroscopy (XPS). Electrochemical properties of the MWCNTs, the pure CeO 2 , and the CeO 2 /MWCNTs nanocomposites electrodes are investigated by cyclic voltammetry (CV), galvanostatic charge/discharge (GDC) and electrochemical impedance spectroscopy (EIS) measurements. The CeO 2 /MWCNTs nanocomposite (at the mole ratio of 1:1) electrode exhibits much larger specific capacitance compared with both the MWCNTs electrode and the pure CeO 2 electrode and significantly improves cycling stability compared to the pure CeO 2 electrode. The CeO 2 /MWCNTs nanocomposite (at the mole ratio of 1:1) achieves a specific capacitance of 455.6 F g −1 at the current density of 1 A g −1 . Therefore, the as prepared CeO 2 /MWCNTs nanocomposite is a promising electrode material for high-performance supercapacitors. [ABSTRACT FROM AUTHOR]

Tin oxide microspheres were successfully obtained through a facile hydrothermal method without any polymer templates or surfactant. The as-synthesized SnO 2 microspheres are composed of large amount of small spheres with average diameters of about 250 nm, and every small sphere consists of numerous primary nanocrystallites with average sizes of about 8 nm. The resultant product was used as sensing material for gas sensor to detect the formaldehyde (HCHO) gas. The gas response, response and recovery time, selectivity and stability were carefully studied. It was found that the response value of the sensor to 100 ppm HCHO was 38.3 at the operating temperature of 200 °C. The gas sensor based on SnO 2 microspheres has excellent gas response, good response-recovery properties, linear dependence, repeatability and selectivity, making it to be a promising candidate for practical detectors for HCHO. [ABSTRACT FROM AUTHOR]

Nanoporous titanium dioxide was synthesized by a hydrothermal method without using of surfactant or template. The structure, morphology, surface chemical states and specific surface area were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and N 2 adsorption-desorption isotherms, respectively. The as-synthesized products are anatase-TiO 2 with small grain size (about 12.27 nm) and high surface area (147.17 m 2 g −1 ). The as-synthesized porous TiO 2 powder was used to fabricate indirect-heating gas sensor whose gas-sensing characteristics toward acetone were investigated. At its optimal operation temperature, the sensor possesses a good sensitivity, selectivity, linear dependence, low detection limitation, and response/recovery, repeatability as well as long-term stability. Especially for the high sensitivity and fast response/recovery, its response reaches 25.97 for 500 ppm acetone, which is several times higher that of the reported TiO 2 -based sensors. The response and recovery times are only 13 and 8 s, respectively. Those values demonstrate the potential of using as-synthesized TiO 2 for acetone gas detection, particularly in the dynamic monitoring. Apart from these, the mechanism related to the advanced properties was also investigated and presented. [ABSTRACT FROM AUTHOR]