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The perovskite structure oxide, CaMnO 3 , has been extensively investigated and applied as a potential microwave absorption material due to its versatile dielectric and spontaneous polarization. However, the low conductivity of pure CaMnO 3 material limits its further application. Herein, to increase dielectric loss and achieve better microwave absorption properties, lanthanum (La)-doped CaMnO 3 (Ca 1-x La x MnO 3) ceramics were fabricated by a high temperature solid state reaction. The results of XRD and XPS show that the La atom was efficiently doped at the Ca site in CaMnO 3 , which carries excess positive charges and affects the valence state of Mn ions and the concentration of oxygen vacancies. Therefore, the conductivity and imaginary permittivity of Ca 1-x La x MnO 3 ceramics increased dramatically with La-doped content. Benefiting from the tunable dielectric and impedance properties, Ca 1-x La x MnO 3 ceramics can be utilized in a highly efficient way to absorb microwave radiation with a thin thickness. The sample with x = 0.04 shows the best microwave absorption property, with an RL min value of -52.63 dB (d = 1.41 mm) and effective absorption bandwidth coves full X band in the thickness range from 1.315 mm to 1.395 mm. [ABSTRACT FROM AUTHOR]

Hydroformylation has been applied in the chemical industry for decades to produce n-aldehydes from 1-olefins and syngas (a mixture of CO and H 2). However, the difficulty of catalyst separation and harsh operating conditions of conventional homogeneous hydroformylation reactions have prompted researchers to explore heterogeneous catalytic strategies. In this work, a novel core-shell structured catalyst comprised of Rhodium nanoparticles (Rh NPs) homogeneously encapsulated in a silicalite-1 zeolite (Rh@S-1) is designed to realize a high activity in 1-hexene hydroformylation. The conversion of 1-hexene over the Rh@S-1 catalyst exhibits as high as 85.8%, and the ratio of n-heptanal to iso-heptanal reaches up to 2.5 at 90 °C. Multiple studies demonstrate that the outstanding catalytic activity over this core-shell structured catalyst can be explained by the highly active homogeneously dispersed Rh NPs and the distinguishable mass transfer effect of the unique and orderly micropores structure of silicalite-1 zeolite. Furthermore, by changing templating agent concentrations during the hydrothermal method, the size of the zeolite crystals can be easily controlled and is proven to be an essential factor affecting the hydroformylation performance. [Display omitted] • Design of core-shell structured Rh@S-1 catalyst by solvent-free hydrothermal method. • High reaction performance in hydroformylation of 1-hexene realized by Rh@S-1. • Synergistic effect of active Rh NPs and the shape selectivity of zeolite micropores. • Zeolite crystals size of Rh@S-1 affected the hydroformylation reaction activity. [ABSTRACT FROM AUTHOR]

• A common carbon nitride delivers great 2eORR activity for H 2 O 2 production in presence of lactic acid as sacrificial agent. • Pyruvic acid is simultaneously produced from selective dehydrogenation of lactic acid. • Other hydroxycarboxylic acids are selectively dehydrogenated into corresponding aldehydic or keto acids. • In-depth experimental and theoretical investigations reveal the detailed reaction mechanism. Photocatalytic H 2 O 2 production is emerging as an alternative technology to contribute H 2 O 2 -based advanced oxidation applications. However, the present reaction systems rarely consider the selective oxidation of sacrificial agent along with oxygen reduction reaction. Herein, we design a reaction system by using hydroxycarboxylic acids as additives to boost photocatalytic H 2 O 2 production. More importantly, hydroxycarboxylic acids could simultaneously be dehydrogenated into aldehydic/keto acids with high selectivity. Lactic acid as one of the typical hydroxycarboxylic acids reveals the feasibility of this hypothesis, delivering 6.56 mM/h of H 2 O 2 generation along with > 70 % pyruvic acid selectivity. The universality of this reaction system is demonstrated by using other hydroxycarboxylic acids. This works sheds new light on coupling H 2 O 2 generation with value-added chemicals production by mild photocatalytic approach. [ABSTRACT FROM AUTHOR]

Here, we demonstrate the selective cellobiose (building block of cellulose) photoreforming for gluconic acid and syngas co-production in acidic conditions by rationally designing a bifunctional polymeric carbon nitride (CN) with potassium/sulfur co-dopant. This heteroatomic doped CN photocatalyst possesses enhanced visible light absorption, higher charge separation efficiency than pristine CN. Under acidic conditions, cellobiose is not only more efficiently hydrolyzed into glucose but also promotes the syngas and gluconic acid production. Density functional theory (DFT) calculations reveal the favorable generation of •O 2 − during the photocatalytic reaction, which is essential for gluconic acid production. Consequently, the fine-designed photocatalyst presents excellent cellobiose conversion (>80%) and gluconic acid selectivity (>70%) together with the co-production of syngas (∼56 μmol g−1 h−1) under light illumination. The current work demonstrates the feasibility of biomass photoreforming with value-added chemicals and syngas co-production under mild condition. [Display omitted] • Bifunctional CN with K, S co-doping is synthesized via a facile calcination process. • Acidic cellobiose photoreforming to simultaneously obtain gluconic acid and syngas. • Cellobiose conversion (>80%) and gluconic acid selectivity (>70%) can be achieved. • Favorable generation of •O 2 − proved by DFT is essential for gluconic acid production. [ABSTRACT FROM AUTHOR]

• Three phosphate ester-based MOFs (UiO-66-(OPO 3) X) containing different amounts and spatial positions were prepared. • UiO-66-(OPO 3) X can efficiently remove Pb2+ from aqueous solution. • Even at pH = 2 and pH = 3, UiO-66-(OPO 3) X maintains a high removal efficiency of Pb2+. • UiO-66-(OPO 3) X has excellent selectivity and anti-interference ability for Pb2+. • The adsorption mechanism was investigated in detail by experiment combined with DFT. Metal-organic framework (MOF) materials have emerged as promising candidates for treating heavy metal wastewater because of their controllable pore size, high specific surface area, and abundant active sites. Nevertheless, the currently reported MOFs usually require near-neutral environments (pH = 5–6) to achieve efficient removal of Pb2+ and cannot be applied to acidic environments (pH = 2–3). In this work, the structurally stabilized zirconium-based MOF UiO-66 was chosen as the object of study. Three phosphate ester-based MOFs (UiO-66-(OPO 3) X) containing different amounts and spatial positions were designed and prepared by simple chemical modification and used to remove Pb2+. Adsorption experiments showed that they could reach adsorption equilibrium in 30 min with excellent adsorption rate. Owing to the unique ionization ability of the phosphate ester group, UiO-66-(OPO3) X maintains a high removal efficiency of Pb2+ even at pH = 2 and pH = 3. In addition, selectivity and competition experiments demonstrated that UiO-66-(OPO 3) X possessed excellent selectivity and anticompetitive ability towards Pb2+.The excellent regeneration performance demonstrates their value for practical application. Moreover, the adsorption mechanism was investigated in detail by experiment combined with density functional theory (DFT). [ABSTRACT FROM AUTHOR]

The seismic response is a critical aspect of structural engineering, as it directly influences the design and safety evaluation of such systems. Structural seismic response becomes more complicated when unavoidable uncertainties in the structure are considered. Therefore, solving and analyzing the stochastic dynamic response of structures efficiently and accurately is of great significance. Various uncertainty quantification methods such as the stochastic finite element method, Monte Carlo method, and polynomial chaos expansion method have made significant progress in this field. However, these methods do not provide a comprehensive study of the seismic response of stochastic structures and efficiency problems rapidly emerge as the number of random variables increases. This paper delivers a comprehensive study of the seismic dynamic response of space truss and reticulated shell structure considering uncertainties in material properties, geometry, and loading. To this end, the finite element model of the structure was first modeled and the deterministic solutions were obtained. Then, polynomial surrogates are modeled for the natural frequency, mode participation factor, mode superposition response, and transient response of the structure under stochastic uncertainties. The sparse grid technique is used to select sparse quadrature points, which overcomes the curse of dimensionality caused by full grid integration. The results demonstrate that the sparse grid-based polynomial chaos expansion is more efficient. Uncertainty quantification reveals the uncertainty of modal analysis, response spectrum analysis, and transient response analysis of space truss and reticulated shell under seismic excitation. In summary, this study provides valuable insights and an efficient and accurate uncertainty quantification tool for the seismic dynamic analysis of stochastic structures, ultimately contributing to safer and more robust structural designs. • Analyzing the seismic dynamic response of stochastic structures comprehensively. • Sparse grid-based PCE for quantifying uncertainty in stochastic dynamics. • Addressing the dimensional catastrophe of traditional non-intrusive PCE. • Sparse grid-based PCE metamodel for post-processing is more efficient and accurate. [ABSTRACT FROM AUTHOR]

To address the issue of low accuracy resulting from approximation errors in conventional interval finite element methods, this study presents an ɛ -accelerated bivariate dimension-reduction interval finite element method. The proposed method aims to accurately and efficiently predict the static response of structures with high dimensionality and large uncertainty parameters. We first approximate the structural interval equilibrium equation using a bivariate dimension-reduction method. An explicit expression for the sequence of displacements is derived by approximating the inverse of the structural interval stiffness matrix using the Neumann series. Adjoint-based sensitivity analysis can effectively avoid the response interval expansion caused by parameter coupling. For improving the convergence speed and computational accuracy, the displacement response sequence is accelerated by a vector ɛ acceleration algorithm and an adaptive strategy. Finally, three engineering structures with uncertain-but-bounded parameters are analyzed with the proposed method. Compared with conventional interval analysis methods, the proposed method effectively balances computational accuracy and efficiency, making it more suitable for non-linear and large uncertainty problems with multiple interval parameters. The study shows that ɛ -accelerated bivariate dimension-reduction interval finite element method has a promising application. • An interval finite element method based on bivariate dimension-reduction is proposed. • Explicit sequences and errors for the bounds of displacements were derived. • Dependencies between parameters are addressed by adjoint-based sensitivity analysis. • Convergence speed and accuracy are improved by the adaptive ɛ algorithm. • Structural response intervals are efficiently and accurately predicted. [ABSTRACT FROM AUTHOR]

This work synthesizes Ni 2 P/ZCS composites to achieve spatial separation of photogenerated carriers, while systematically investigating the bifunctional properties and mechanisms of cellulose photoreforming. [Display omitted] • Preparation of Ni 2 P/ZCS to achieve space charge separation of photogenerated carriers. • Schottky junction in interface effectively improves catalyst photogenerated carrier separation and photostability. • Demonstrates excellent bifunctional catalytic performance for Ni 2 P/ZCS. • Ni 2 P/ZCS composites photoreforming cellulose mechanism is proposed for the first time. The Biomass photoreforming is emerging as an alternative and promising technology to simultaneously produce value-added chemicals and solar fuels. However, photoreforming of the biomass macromolecular remains a great challenge due to the lack of bifunctional photocatalyst and insight of detailed mechanism. Herein, we design the Ni 2 P onto the two-dimension Zn 0.3 Cd 0.7 S (Ni 2 P/ZCS) as the electron migration layer to realize the spatial separation of photogenerated carrier, which facilitates the depth investigation on the redox reaction. As a result, the Ni 2 P/ZCS exhibited dually catalytic performance (9.16 mmol g−1h−1 of H 2 generation along with 1.48 mmol g−1h−1 of lactic acid production) from cellulose photoreforming. Systematic experiments and density functional theory (DFT) were performed to reveal the bifunctionality and detailed mechanism. This work demonstrates a well concept on biomass photoreforming with the rational design of bifunctional photocatalysts. [ABSTRACT FROM AUTHOR]

For drilled piles in rock stratum, predictions of axial load-deformation response offer guidance for the preliminary design. In this development, the profiles of socket wall would be idealized as similar triangular asperities, and the expansion of the shaft is laterally confined across the socket wall under constant normal stiffness conditions (CNS). The side shear resistance contributes from the overriding (dilation) and degradation (shearing) of asperities, and the degradation of asperities develops asynchronously. In particular, a correlation is derived between asperity geometry properties and the global strength by including a simplified degradation criterion of the asperity. The proposed model can be considered as a generalization of Patton's model, extending the case of regular triangular asperities to the similar ones. On this basis, the predicted shear mobilization relative to displacement can then be employed to update the load transfer function. Semi-analytical solutions to this problem have been conducted by a finite-difference scheme. Based on the validation of a case study, the proposed prediction exhibits general accuracy with reference to the field observations. To investigate the effect of asperity inclination on the ultimate and residual strengths, a parametric study has also been conducted afterwards. Comparing with an existing method, the prediction from the proposed model captures a ductile response and depicts a notable nonlinear behavior. [ABSTRACT FROM AUTHOR]

A phenanthroline[9,10-d] imidazole-based fluorescent sensor was synthesized for Hg2+, accompanied by change of fluorescence from null to blue. [Display omitted] • A novel phenimidazole fluorescence sensor compound 1 was developed. • The sensor compound 1 exhibited fluorescent response to Hg2+. • Low cost, high sensitivity, superior selectivity, and low detection limit for Hg2+. • The sensor compound 1 had advantages in detecting Hg2+ in practical applications. Herein, a phenanthro[9,10-d] imidazole Schiff based "turn-on" fluorescence sensor (compound 1) was synthesized by 4-hydroxy-3-nitrobenzaldehyde and 9,10-phenanthrenequinone. In DMF/PBS buffer solution (1:4, v/v, pH 7.4), compound 1 responsed to Hg2+ with high sensitivity (detection limit was 45.76 nM) and rapid response (completed within 5 s), accompanied by the fluorescence change from null to blue. The binding ratio of compound 1 to Hg2+ was 1:1, and the binding constant was 2.933 × 106 M−1. Through detailed analysis of 1H–1H COSY and 1H–13C HSQC spectra, we proposed the possible fluorescence emission mechanism of compound 1 and Hg2+, and verified the recognition mechanism of compound 1 through density functional theory (DFT) calculation. Compound 1 was successfully used to detect Hg2+ in actual water samples, the recovery was 91 %–106 %, and the relative standard deviation (R.S.D.) was less than 2.5 %, which provided possibility for compound 1 to be used as a sensor in environmental research. [ABSTRACT FROM AUTHOR]

This study deals with the formulation of an analytical solution for load transfer in drilled shaft and its application. The emphasis is on quantifying the mobilization of side resistances, which are closely related to shear behaviors of the concrete-rock interface. In this modelling, the side resistance is idealized by using elasticity-brittleness-plasticity, and a simple slip-line field is built to identify the critical shear displacement. The closed-form solution of load transfer is obtained by using the proposed shear model. Comparison between predictions and field observations is also made to validate performance of the proposed method. [ABSTRACT FROM AUTHOR]

The ultimate bearing capacity of an eccentrically loaded strip footing above twin square tunnels buried in rock masses was examined using the generalized Hoek-Brown (GHB) yield criteria. To get reliable findings, the stability assessments were carried out using finite element limit analysis (FELA) code in combination with a sophisticated adaptive remeshing approach. Case studies with two different tunnel layouts, parallel and symmetrical, were examined. Comprehensive parametric analyses were given to demonstrate the effect of load eccentricity, rock mass strength parameters, and tunnel position on the stability of the strip footing. The visualized results of the FELA programme were presented to show how the failure mechanism would change with different influential factors. Moreover, the results were validated by comparing them to earlier investigations. [ABSTRACT FROM AUTHOR]

Micro/nanoplastics (MNPs) are widespread environmental pollutants that cause high health risks. However, high heterogeneity in particle sizes and chemical compositions of MNPs make their accurate characterization extremely challenging. Herein, we established a matrix-assisted laser desorption ionization-Fourier transform ion cyclotron resonance mass spectrometry (MALDI-FTICR MS) strategy for the unambiguous characterization of different types of MNPs with high performance, including polystyrene, polyethylene glycol terephthalate, polyamide, polymethyl methacrylate, acrylonitrile butadiene styrene copolymer, and polycarbonate. The MNP sample preparation and detection conditions were systematically optimized by using response surface methodology, and the MS detection signal-to-noise ratios were improved 1.5 times on average. The ultrahigh mass resolution of FTICR MS is crucial to the unambiguous elucidation of MNP structures. We demonstrate that this MS strategy is highly efficient in the characterization of polymer constitutions of environmental MNPs derived from foam, bottles, cable ties, and compact discs, providing a promising tool for MNP detection and safety evaluation. [Display omitted] • PS, PET, PA, PMMA, ABS, and PC MNPs were unambiguously characterized by MALDI-FTICR MS. • The MS SNRs were improved by an average of 1.5 times after detection condition optimization. • MNPs derived from foam, bottles, cable ties, and compact discs were successfully identified. [ABSTRACT FROM AUTHOR]

Glucose isomerization into fructose is a key process in industry for biomass valorization to produce value-added biofuels and biochemicals. Herein, considering the essential role of Lewis acid-base sites in proton transfer during glucose isomerization and hydrogen evolution process, a bifunctional polymeric red carbon nitride (PRCN) is rationally designed and fabricated by the salt-template-induced carbon incorporation strategy. The incorporation of carbon and potassium in the PRCN leads to the transient redistribution of photogenerated charges, acting as the electron-enriched Lewis base site and acid site for the deprotonation of O2-H and activation of aldehyde group of glucose, respectively. Besides, the interfacial Schottky junction boosts H 2 production under visible light irradiation. This work demonstrates the feasibility of biomass photorefinery with H 2 and value-added chemicals co-production under mild condition. [Display omitted] • Carbon incorporation in PRCN extended light absorbance to near-infrared region. • Heteroatomic carbon and potassium acted as Lewis base and acid site for glucose isomerization. • Schottky junction boosted H 2 co-production under visible light irradiation. • Electron-enriched C site reduced active H* transfer for glucose and promoted H 2 co-production. [ABSTRACT FROM AUTHOR]

Direct shear tests on samples containing similar triangular asperities have been carried out under constant normal stiffness (CNS) conditions, and observations demonstrated that there exists local lift-off of shallower asperities across the interface, resulting in a redistribution of local stresses and further impacting the global shear behavior. This study further modifies the existing theoretical model based on multiple-asperity configurations, previously presented by the authors. The proposed method relates the normal and shear stresses on the individual asperity to interface strength and corresponding displacement in terms of the asperity inclination and contact areas. The emphasis is on quantifying the number of shallower asperities that would be lifted off when the closely contacted asperities are dislocated by an amount of interface dilation. In addition to the mechanism of local lift-off itself, the resultant redistribution of global shear stress on remaining asperities can be also taken into account. The proposed model is verified by predicting experimental observations published elsewhere, and the comparison appears to be satisfactory. [ABSTRACT FROM AUTHOR]

A ternary photocatalyst TiO 2 -Au-CdS based on three-dimensionally ordered macroporous TiO 2 (3DOM TiO 2 ) was successfully prepared to enhance the light absorption, extend the light responsive region, reduce the recombination rate of charge carriers and promote the efficiency of water splitting H 2 evolution ultimately. The obtained 3DOM TiO 2 -Au-CdS powder has a pure anatase phase of TiO 2 and greenockite structured CdS according to the XRD results and TEM analysis. Au nanoparticles (AuNPs) and CdS were evenly distributed in the 3DOM structure which enhances H 2 -generation rate under visible light by improving light harvesting and utilizing its mass transfer facilitation. As a result, the hydrogen generation rate (1.81 mmol h −1 g −1 ) using 3DOM TiO 2 -Au-CdS photocatalyst under visible light irradiation was 13-fold higher than the binary 3DOM TiO 2 -CdS reference photocatalyst. Under ultraviolet-visible light, the photogenerated electrons in TiO 2 would be transferred to recombine with the holes of CdS and under visible light, electrons would move to the conduction band (CB) of TiO 2 from CdS via AuNPs. The two different types of internal electron-transfer process in the ternary photocatalyst under ultraviolet and visible light were proposed respectively and both would efficiently reduce the recombination rate of photogenerated electrons and holes thus stimulate H 2 evolution rate. The present work demonstrated an excellent example of the synergistic effect of the light absorption enhancement by 3DOM structure, the photosensitizing and electron reservoir effect of AuNPs and the reduction of recombination rate of charge carriers by CdS to highly promote the photocatalytic activity in water splitting reaction. [ABSTRACT FROM AUTHOR]

Photoreforming of lignocellulosic biomass is an emerging and sustainable strategy for coproduction of high-value chemicals and fuels. Challenges remain to selectively convert biomass macromolecular via sunlight-driven photocatalysis due to limited mass diffusion, insufficient charge separation and lack of mechanistic understanding. Herein, inspired by natural photosynthesis, we demonstrate a hierarchically threedimensionally ordered macroporous (3DOM) TiO 2 -Au-CdS Z-scheme heterojunction photocatalyst to improve mass diffusion, charge separation and light absorption efficiency. We show the photocatalytic cleavage pathway of cellulose β-1,4-glycosidic linkage (the most abundant linkage within biomass) over 3DOM TiO 2 -Au-CdS heterojunction by using cellobiose as a model component. Similar to the oxidative enzymes in nature, the all-solid-state Z-scheme photocatalyst demonstrates oxygen insertion at C1 position followed by the elimination reaction, which oxidatively cleaves the β-1,4-glycosidic bond and results in gluconic acid and glucose generation. In presence of oxygen, glucose is further oxidized into gluconic acid which is subsequently oxidized or decarboxylated into glucaric acid or arabinose. The present study may serve as a framework to rationally design photocatalyst to reveal mechanistic understanding of biomass photoreforming towards high-value fuels and chemical feedstocks. [Display omitted] • Bioinspired 3DOM TiO 2 -Au-CdS heterojunction improves mass diffusion, light absorption and charge separation efficiency. • First demonstration of photocatalytic cleavage mechanism of cellulose β-1,4-glycosidic linkage. • Photocatalysis shows similar reaction pathway to the oxidative enzymes in nature. • Photogenerated·O2- and·OH play a synergistic effect for cellulose photoreforming. • Gas fuels (H 2 , CH 4 , CO) cogenerated during cellulose photocatalytic valorization. [ABSTRACT FROM AUTHOR]

Abstract: Ground-based zenith-sky DOAS observation was carried out from October 1, 2009 to September 30, 2010 in Shanghai, China to measure the O4 and H2O absorption in visible band and to illustrate the dependence of their correlation slope on the aerosol pollution type. Good correlations between O4 and H2O DSCDs can be found through linear regression analysis whether it was sunny, cloudy, overcast, or rainy. The correlation slope varied seasonally in the order of summer < autumn, spring < winter. In particular, the correlation slope and fluctuation were small in the summer. It was found that slope values also relied on sky conditions generally in the sequence of dusty > sunny > cloudy > overcast > rainy. The implication of the variation of slope to the aerosol pollution type was discussed for typical heavy dust and haze episodes occurred in March 2010 and October 2009, respectively. As the correlation slope abruptly increased during the heavy dust due to low moisture content and enhanced O4 absorption caused by abundant suspended dry crustal particles, the slope dropped suddenly in the haze episode owing to the significant augment of H2O absorption. Thus, the much discrepant correlation patterns may be regarded as a characteristic signature for dust and haze events. [Copyright &y& Elsevier]

This as-fabricated 3DOM TiO 2 -Au demonstrates good selectivity for arabinose production from glucose photoreforming along with gas fuel co-production due to the synergistic effects of improved glucose-photocatalyst interaction, no-metallic state Au(I), enhanced electron generation and charge separation, localized surface plasmon resonance (SPR). [Display omitted] • Hierarchical 3DOM TiO 2 -Au enhanced glucose conversion and arabinose selectivity. • Selectivity depends on glucose-catalyst interaction/charge separation/LSPR effect. • First demonstration of gold chemical state towards biomass photoreforming. • Direct C1-C2 α-scissions mechanism of glucose was evidenced by various techniques. • Gas fuels (H 2 , CH 4 , CO) cogenerated via transient dehydration and hydrogenation. Glucose photoreforming provides a promising alternative strategy for biomass valorization. However, the use of harsh environment (high alkalinity or organic solvents) and low product selectivity due to non-selective free radical oxidative cleavage limit their application in large-scale settings. Here, we show photoreforming of glucose to arabinose with high selectivity in water using gold nanoparticles decorated three dimensionally ordered macroporous TiO 2 (3DOM TiO 2 -Au). We demonstrate that the hierarchically porous 3DOM architecture and Au nanoparticles enhance glucose conversion and arabinose selectivity by improving glucose-photocatalysts interaction, electron generation, charge separation, and localized surface plasmon resonance (LSPR) induced light absorption. The 3DOM TiO 2 -Au produces arabinose via the direct C1-C2 α-scissions mechanism as evidenced by 13C labeled glucose at C1 position. Our experimental results demonstrate the presence of Au(I) is crucial for glucose to arabinose selective conversion. Aside from arabinose production, 3DOM TiO 2 -Au also generates considerable amount of gas fuels (H 2 , CH 4 and CO) from transient dehydration and hydrogenation reaction of the by-product formic acid. The present work demonstrates a green and promising approach to convert biomass derived feedstocks into value-added chemicals along with gas fuel production. [ABSTRACT FROM AUTHOR]

Bioleaching of a marmatite flotation concentrate by Acidithiobacillus ferrooxidans was carried out at 35 °C and an initial pH of 2.0 on an orbital shaker at 160 min−1. Experimental results indicated that the adapted strains markedly increased the dissolution rate of marmatite when compared with the sterile control and the original strains. The fact that Fe3+ ions played a key role in the dissolution of marmatite was demonstrated by the chemical leaching of the concentrate with different concentrations of Fe3+ ions. The main role of the microorganisms was to oxidize Fe2+ ions into Fe3+ ions during the bioleaching process.S.E.M. observations showed the morphological features of the mineral sample and leach residues. The cross-section image of residue particles revealed two different regions, a periphery consisting of reaction products and an undissolved core. It was shown by X-ray diffraction and EDX analysis that the leach residues were composed of elemental sulfur, precipitate of jarosite and undissolved mineral impurities. These facts suggested that the elemental sulfur formed was not completely oxidized and dissolved only partially in the marmatite bioleaching even in the presence of bacterial strains. The sulfur product coated the residue particles and negatively affected the dissolution of marmatite. The marmatite was dissolved preferentially during the bioleaching process by Acidithiobacillus ferrooxidans, as compared with other sulfide minerals such as pyrite and galena in the concentrate. [Copyright &y& Elsevier]

Random adaptive finite element limit analysis (RAFELA) is introduced to investigate the stability of the footing-voids system with random soils. The emphasis of this study is, for the footing-void system, on quantifying the influence of spatial variability on its bearing capacity and the failure probability. Of particular interest is that random field theory is utilized to characterize the spatial variability of soil, and at the same time, failure probability is calculated by imposing Monte-Carlo simulations on independent cases. Strict close bearing capacity could be obtained within the scope embraced by upper bound (UB) results and lower bound (LB) results. By imposing the proposed modelling, comprehensive parametric studies were carried out, especially for the soil spatial correlation parameters and geometry parameters. The results indicated that the failure probability would increase with the farther distance between the void and the footing, the greater coefficient of variation (COV) and the smaller vertical correlation length. Detailed design tables were presented to assess potential failure probability under different conditions. Typical failure patterns are also summarized, revealing a positive correlation between the failure probability and the diffusion degree of failure curves. [ABSTRACT FROM AUTHOR]

Smart windows with excellent near-infrared (NIR) light shielding capacity and controlled visible light transmittance are expected to reduce building energy consumption and improve indoor comfort. However, the ability of current thermochromic materials to regulate solar gain with the tunable extinction of phase-change materials is still far from optimum. In this work, an fluorine (F)-doped ATO (FATO) nanocrystals (NCs) are designed as a photothermal material to optimize the solar modulation of thermochromic hydrogels. F ion doping can modify the electronic structure of ATO, resulting in a high concentration of oxygen vacancies and free electrons, thereby enhancing the NIR absorption performance and photothermal conversion performance of the ATO NCs. On this premise, the designed smart window based on FATO NCs and thermochromic hydrogels exhibits the remarkable features of excellent NIR shielding, high initial visible transmittance and fast response speed. The window is capable of shielding 99.5% of the solar radiation from 300 to 2500 nm and permitting 75.0% of initial visible light. Moreover, the simulated indoor temperature of the smart window was 17.2 °C lower compared with the black one, demonstrating potentials in practical application of building energy saving. [Display omitted] • Novel chain-like FATO NCs were prepared by precipitation-hydrothermal method. • F-doping optimized electronic structure of ATO and improved the LSPR absorption. • The fabrication of FATO-PNC hydrogel provides a novel idea for smart window. • The smart window could shield 99.5% of solar radiation after optical switching. [ABSTRACT FROM AUTHOR]

• A novel diarylethene derivative 1O with the unit of N-(2-(hydrazinecarbonyl)phenyl)benzamide has been designed and synthesized successfully. The substance has a simple structure and easy-to-obtain raw materials. It has also been successfully applied to test actual water samples. • 1O displays rapid, highly selective and sensitive fluorescent signal changes for Al3+. • 1O exhibits excellent anti-interference performance. A novel diarylethene derivative 1O with the unit of N-(2-(hydrazinecarbonyl)phenyl)benzamide was designed and synthesized successfully. The sensor showed excellent photochromism and specific fluorescent detection toward aluminum ion with rarely interfering. The emission intensity could increase nearly by 100 folds with aluminum ion and the color changed from dark to Aqua green. The low limit of detection (LOD) of 1O was determined as 3.26 × 10-8 mol L-1. Additionally, the sensor could be used in logic circuit and aluminum ion detection in untreated water. [ABSTRACT FROM AUTHOR]

The properties of socket wall significantly affect the loading capacity of a rock socketed pile, and the shear mobilization relies heavily on the roughness of the socket surface and the boundary condition in reality. In this study, laboratory tests have been conducted to investigate the performance of concrete-rock interface shear under constant normal stiffness (CNS) condition and, in particular, an alternative profile to characterize the interface roughness is assembled as series of similar triangular asperities. The profiles of rock samples differing in the dimension of asperities have been divided into five categories (including one kind of regular triangular asperities for comparison). Direct shear tests on the samples are carried out under CNS conditions, with different initial normal loads and normal stiffnesses. The observations indicate that the shear behavior of concrete-rock interface is highly dependent on the uniformity of asperity geometry; compared with the roughness of similar triangular asperities, the one of regular asperities behaves more brittleness and shows a higher peak strength as well as a lower residual strength. In addition to the general tendency, it is found that the local lift-off of some asperities is pronounced relied heavily on their heights, and the redistribution of local stresses can further affect the global shear behavior. The size-dependent sequence of asperity failure can be also observed, confirming the earlier theoretical anticipation reported by the authors. Careful observations during this testing made it possible to develop a micromechanics-based model published elsewhere, and the comparison between them are presented. [ABSTRACT FROM AUTHOR]

The undrained stability of dual circular tunnels buried in spatially random soils is investigated by imposing the random adaptive finite element limit analysis (RAFELA). The emphasis is on quantifying the effect of influential factors including the geometry parameters and spatially variability parameters on the bearing capacity and failure probability of tunnels by assuming a lognormal distribution on undrained shear strength within a spatial correlation structure. Predictions were obtained by the scope enclosed by upper bound (UB) and lower bound results (LB) results within 5% relative errors. To account for a combined effect simultaneously caused by depths of tunnels, spaces between tunnels, soil weights, and spatially variability parameters on the stability of tunnels, all independent variables are involved in parametric studies in pairs. Results revealed several failure patterns and announced how the stability evolves with changes in tunnel geometry and soil spatial variability. [ABSTRACT FROM AUTHOR]

In this study, finite element limit analysis (FELA) is employed to investigate the undrained seismic bearing capacity of strip footings placed on two-layered slopes. Upper bound theorem (UB), lower bound theorem (LB) and adaptive meshing technique were used in parametric studies to investigate the effects of various factors on seismic bearing capacity N cs and failure mechanism, especially the seismic coefficient k h and the shear strength ratio of top layer and bottom layer c u1 / c u2. The angle of the slope β , the absolute strength of top layer c u /γ B , horizontal offset distance b and the thickness of top layer D are also taken into consideration. Furthermore, the comparisons between present study and previous studies are provided. Detailed design tables are presented to distinguish the failure patterns and estimate the seismic bearing capacity of slopes under different conditions. [ABSTRACT FROM AUTHOR]

Boundary conditions significantly affect the shear behavior of concrete-rock joints. Most of the joint models have been developed for the constant normal load (CNL) conditions but cannot be directly extended to the more general constant normal stiffness (CNS) conditions, as a 'normal stiffness (K)' serves as a spring in such a condition to constantly adjust the normal confinements in terms of the dilation. In this study, the authors attempted to set up numerical modeling of concrete-rock joint shearing by layered over-compaction method based on PFC2D. An obvious extension is that explicit spring-based kinetic equations were employed to govern the travel of the upper shear chamber, by which the system can be dynamically balanced at each timestep to permit CNS conditions. Also, an alternative joint profile consisting of multiple similar triangular asperities (STAs) was defined in the presented modeling, taking account of both varied asperity heights and sizes. The comparisons with laboratory observations, recently published by the authors, demonstrated that the model makes reasonable predictions of shear behavior, especially well capturing the essential mechanisms of STAs profile, including dilation, shearing, and local lift-off. Compared with CNL conditions, the CNS conditions can better mobilize the peak shear strength, maximum normal stress, micro-cracks, and force chain. Results indicate that an adequate choice of CNL or CNS conditions is of significance to evaluate the side resistance, loading capacity, or engineering stability in geotechnical engineering practices. [ABSTRACT FROM AUTHOR]

Lignocellulosic biomass valorization is regarded as a promising approach to alleviate energy crisis and achieve carbon neutrality. Bioactive enzymes have attracted great attention and been commonly applied for biomass valorization owing to their high selectivity and catalytic efficiency under environmentally benign reaction conditions. Same as biocatalysis, photo−/electro-catalysis also happens at mild conditions (i.e., near ambient temperature and pressure). Therefore, the combination of these different catalytic approaches to benefit from their resulting synergy is appealing. In such hybrid systems, harness of renewable energy from the photo−/electro-catalytic compartment can be combined with the unique selectivity of biocatalysts, therefore providing a more sustainable and greener approach to obtain fuels and value-added chemicals from biomass. In this review, we firstly introduce the pros/cons, classifications, and the applications of photo−/electro-enzyme coupled systems. Then we focus on the fundamentals and comprehensive applications of the most representative biomass-active enzymes including lytic polysaccharide monooxygenases (LPMOs), glucose oxidase (GOD)/dehydrogenase (GDH) and lignin peroxidase (LiP), together with other biomass-active enzymes in the photo−/electro- enzyme coupled systems. Finally, we propose current deficiencies and future perspectives of biomass-active enzymes to be applied in the hybrid catalytic systems for global biomass valorization. • Lignocellulosic biomass valorization is an effective approach to alleviate energy crisis and achieve carbon neutrality. • The photo−/electro-enzyme coupled systems are more sustainable and greener to obtain fuels and value-added chemicals. • The state-of-the-art research progress of biomass-active enzymes in bio-photo/electro hybrid systems have been discussed. • Biomass-active enzymes hold great potentials in bio-photo/electro hybrid catalytic systems for global biomass valorization. [ABSTRACT FROM AUTHOR]

Complex structures and morphologies in nature endow materials with unexpected properties and extraordinary functions. Biotemplating is an emerging strategy for replicating nature structures to obtain materials with unique morphologies and improved properties. Recently, efforts have been made to use bio-inspired species as a template for producing morphology-controllable catalysts. Fundamental information, along with recent advances in biotemplate metal-based catalysts are presented in this review through discussions of various structures and biotemplates employed for catalyst preparation. This review also outlines the recent progress on preparation routes of biotemplate catalysts and discusses how the properties and structures of these templates play a crucial role in the final performance of metal-based catalysts. Additionally, the application of bio-based metal and metal oxide catalysts is highlighted for various key energy and environmental technologies, including photocatalysis, fuel cells, and lithium batteries. Biotemplate metal-based catalysts display high efficiency in several energy and environmental systems. Note that this review provides guidance for further research in this direction. The principle of biotemplate catalysts and different synthesis methods are introduced. Different structures resulted from biotemplating and examples of each category are analyzed. Finally, the application of biotemplate catalysts in energy and environmental systems is presented. [Display omitted] • Different preparation methods for biotemplate metal-based catalysts were reviewed. • Examples of biotemplates used for catalysis purposes were presented. • Biotemplate catalysts showed remarkable potential for photocatalysis, fuel cell, and lithium battery. [ABSTRACT FROM AUTHOR]

The shear behavior of concrete-rock joints with similar triangular asperities (STAs) was investigated by numerical direct shear tests under constant normal stiffness (CNS) conditions based on particle flow code (PFC), and numerical models were validated by laboratory observations recently published by the authors. The failure patterns and shear load transfer of asperities on the joints were revealed in terms of shear micro-cracks and shear force chains on the micro-scale. For comparison, joints with conventional profile, regular triangular asperities (RTAs), were also examined. The comparisons showed that a prominent ductile behavior at post-peak most likely occurred for the STAs profile owing to asynchronous asperity failure rather than brittle shear caused by a synchronous failure of the RTAs profile. Results also indicated that there would exist a critical inclination to limit the further mobilization of joint dilation and it may be useful to guide the preliminary design of the rock-socketed pile foundation. [ABSTRACT FROM AUTHOR]

Finite element limit analysis (FELA) is used to study the undrained bearing capacity of strip footing above voids in two-layered clays. Based on the FELA results, design charts and equations are provided to calculate the undrained bearing capacity factor N s . The impact of parameters on N s also has been investigated, including undrained shear stress ratio of the soil, thickness of the top layer, location, size, width, height and spacing of the voids. The failure mechanisms for a single void maybe classified into three categories: roof failure, combined roof and wall failure, bearing failure without void failure. [ABSTRACT FROM AUTHOR]

• Two modes dominate wind-induced response of single-span and three-span frame canopies. • Propose generalized modal force spectrum formula for two dominant modes. • Propose semi-analytical expressions of equivalent static wind loads for canopies. Wind-induced response, spectrums of the modal generalized force, and equivalent static wind loads (ESWLs) of railway station canopies with single-span and three-span frame are investigated. The results show that the first mode dominates horizontal displacements and frame column stresses, and the second mode dominates vertical displacements and frame beam stresses of the canopy frames. The unfavorable wind directions are determined for the center, near-center and end frames. Based on wind tunnel test results, parameters of simplified mean wind dynamic pressure coefficients and the generalized modal force spectrum formula for the first and second modes are proposed for different canopy span, opening widths and building height ratios of the station building to the canopy. Combining above-mentioned wind-induced response characteristics with the analysis method of universal ESWLs, the ESWLs are derived as the superposition of the peak inertia forces of the two dominating modes, and all nodal displacements and all member stresses under this unique ESWLs are equivalent to the actual dynamic peak responses. The numerical example verifies that all nodal displacements and member stresses calculated by the proposed semi-analytical formula simultaneously agree well with the actual dynamic peak response. [ABSTRACT FROM AUTHOR]

C f /SiC composite is an excellent structural and functional material, silicon carbide nanowires (SiCnws) are not only a toughening material but also a great application in the field of microwave absorption. In this study, SiCnws are grown on the surface of carbon fiber (C f) by polymer impregnation and pyrolysis, and the SiC matrix was prepared by chemical vapor osmosis method. The SiCnws are introduced to enhance the mechanical and microwave absorption properties simultaneously. After 3 impregnations, the flexural strength of the composite was 107.35 ± 10 MPa. When the thickness is 1.86 mm, the minimum reflection loss value is −41.08 dB, and the effective absorption bandwidth (RL ≤ −10 dB) is 3.86 GHz. Furthermore, the microwave absorption mechanism of the material is discussed. This work provides a new method to prepare lightweight, stable and high-performance microwave absorption materials, and these materials are expected to be used in high temperature environments. [ABSTRACT FROM AUTHOR]

High efficiency extractants play a necessary role in the selective removal of uranium from rare earth minerals. In this paper, a novel cyclic bidentate diamine extractant, 1, 4-dioctyl-1, 4-dihydroquinoxaline-2, 3-dione (DODQ), was synthesized, and the complexation and extraction of UO 2 2+ in nitric acid medium were systematically studied. The results indicate that DODQ exhibits a unique combination of properties in removing UO 2 2+, with an extraction capacity 132 times higher than that of DODPhOA (acyclic structure). Extraction isotherm experiments and slope analyses illustrate the formation of a 1:1 DODQ/UO 2 2+ regime during the extraction process. Electrospray mass spectrometry, fluorescence spectroscopy, and X-ray crystal diffraction analyses further corroborated its stoichiometric properties. In addition, DODQ can remove UO 2 2+ from rare earth solutions containing UO 2 2+ with high selectivity. This study provides an alternative method to separate uranium from the leaching solution of rare earth ore and has a new understanding of the coordination and complexing behavior of UO 2 2+ with bidentate oxygen-containing ligands. Due to the design of the bidentate oxygen of the extractant structure itself, which is orthogonal to the uranyl ion, DODQ has a good extraction ability and selectivity towards UO 2 2+, and achieves the separation of UO 2 2+ and Ln3+. [Display omitted] • A new and effective extractant for UO 2 2+ is synthesized and characterized. • Fixing the orientation of carbonyl groups (C=O) onto the extractant structure. • The extraction capacity of DODQ was determined to be 132 times higher. • The extraction ability of 0.1 mol/L DODQ is better than that of 0.1 mol/L TBP. • DODQ can selectively concentrate UO 2 2+ in a rare earth ore simulation solution. [ABSTRACT FROM AUTHOR]

[Display omitted] • Two fused-ring electron acceptors based on eight thiophene rings are developed. • The developed acceptors exhibit strong near-infrared absorption beyond 1000 nm. • The effects of core-extension and terminal fluorination have been investigated. • Terminal fluorination has a greater impact on molecular photoelectric properties. • 6TIC-4F device achieved one of the highest PCE among narrow bandgap acceptors. Understanding the relationship between the molecular structure and photoelectric properties of fused-ring non-fullerene acceptors (NFAs) is of far-reaching significance to the development of organic solar cells (OSCs). Herein, six NFAs based on multiple thiophenes (4 T, 6 T and 8 T) are employed to systematically probe the synergistic effects of extending central core size and terminal fluorination. The absorption results manifest that the molecular absorption is comprehensively affected by molecular crystallinity, planarity, conjugation length and intramolecular electron push–pull effect, simultaneously. The intensity of electron push–pull effect is not only related to the electron-donating ability of central core and the electron-withdrawing ability of end group, but also may be related to the distance between the positive and negative centers. The extension of central core leads to the more planar backbone and stronger crystallinity of NFAs, and less energy loss (E loss) in its based OSC. Compared with the extension of central core, terminal fluorination has a greater impact on molecular photoelectric properties. The terminal fluorination significantly enhances the push–pull effect, lowers the energy levels, and slightly increases the vibrational relaxation. As a result, the strongest crystallinity and coplanarity of 8TIC-4F lead to a low vibrational relaxation of 0.18 eV, which makes PTB7-Th:8TIC-4F device exhibit a small E loss of 0.51 eV and a high efficiency of 10.4%. In addition, the fluorinated 6TIC-4F with suitable core size exhibits suitable energy level, absorption, crystallization, and phase separation morphology, making its as-cast device up to 11.61% efficiency. To the best of the authors' knowledge, the PCE of 11.61% for PTB7-Th:6TIC-4F based device without any treatment is one of the highest values reported for the NAFs with over 1000 nm absorption. [ABSTRACT FROM AUTHOR]

Long-term observation of atmospheric nitrous acid (HONO) was performed from August 2010 to June 2012 in urban area of Shanghai, China. In total, valid data for nineteen months were obtained. The monthly average HONO mixing ratio varied from 0.60 ppb in February 2011 to 1.20 ppb in December 2010, but no obvious monthly or seasonal variations were observed. The mean mixing ratio of HONO was obtained as 0.92 ± 0.57 ppb, with average HONO mixing ratio of 1.08 ± 0.63 ppb for night-time, and 0.76 ± 0.44 ppb for daytime. It was found that HONO mixing ratio is dependent on NO2 mixing ratio both in daytime and at night. Besides, high HONO level during daytime implicates that strong daytime sources must be active in Shanghai. The ratio of HONO to NO2 varied from 0.3% to 42.3% with a typical error of 1% and more than 99% of them below 17%. When NO2 mixing ratio was above 30 ppb, the HONO/NO2 ratio (HONO/NO2 averaged over 5.0 ppb intervals of NO2 mixing ratio) was nearly constant at 3.3 ± 0.2%. When the NO2 mixing ratio is below 30 ppb, however, the HONO/NO2 ratio appeared to increase as the NO2 mixing ratio decreased. Additionally, HONO/NO2 ratio depends obviously on relative humidity at night, while there is no obvious correlation between them during daytime. The average conversion frequency of HONO in sixteen selected days was about 0.007 h−1 under different NO2 pollution scenarios and higher conversion frequency tends to be occurred at lower NO2 levels. [ABSTRACT FROM AUTHOR]

An asymmetric failure mode of soil in front of laterally loaded piles at the slope crest is presented to estimate the pile bearing capacity in this study. The effect of soil shear strength below the rotation center is taken into account by postulating the suppositional sliding curve and corresponding mobilization coefficient of soil strength. Subsequently, the soil resistances above the rotation center at soil failure can be obtained by upper bound theorem of limit analysis. Employing static equilibrium equations, the analytical solution of lateral bearing capacity of piles is assessed by adopting the concept of effective embedment depth. The analytical solution, considering the the slope effect on limiting force profile, is then validated by numerical predictions and full-scale tests. Furthermore, a non-dimensional coefficient, capacity ratio, is proposed to characterize the slope effect on the bearing capacity of laterally loaded piles, and the range of capacity ratio for different internal friction angles are differentiated as different distribution areas. The effect of distance between the pile and slope crest on pile bearing capacity is further investigated, and the capacity ratios appear to be approximatively linear with normalized distance λ and would increase to 1 until λ exceeds the critical value. [ABSTRACT FROM AUTHOR]

Enhanced visible-light-driven porous O/P-C 3 N 4 for persulfate photoactivation to remove refractory organic pollutants (bisphenol A and 2-mercaptobenzothiazole) and depolymerize lignin to vanillic acid and various gases. [Display omitted] • Surface electron density on HAPA-CN was enhanced by oxygen and phosphorus doping. • 0.05 HAPA-CN exhibits excellent performance for persulfate photoactivation to remove BPA and MBT. • In-depth exploration of the intermediate products during the photodegradation. • Remarkable sodium lignosulfonate conversion and vanillic acid selectivity achieved. • The transformation of sodium lignosulfonate synergistically produces a variety of gases (H 2 , CO, CH 4 , C 2 H 4 , C 2 H 6). In this research, an enhanced visible light response of oxygen and phosphorus-doped porous g-C 3 N 4 (HAPA-CN) was prepared by thermo-polymerization of urea, hydroxyacetic acid and phytic acid. Its internal structure was verified by solid-state nuclear magnetism (NMR) and secondary ion mass spectrometry (SIMS). The surface electron density on HAPA-CN was enhanced by the inclusion of oxygen and phosphorus. The boosted photocatalytic activity was attributed to the high spectral utilization of sunlight and meliorated charge separation efficiency. The experimental results showed that the 0.05 HAPA-CN/persulfate (PS) system exhibited a higher efficiency in the photodegradation process of bisphenol A (BPA) and 2-mercaptobenzothiazole (MBT). Compared with ordinary g-C 3 N 4 , the integration of photocatalysis and persulfate oxidation led to an increase in the removal of BPA and MBT pollutants, which increased by 68.11 and 11.18 times, respectively. 0.05 HAPA-CN also exhibited a certain photodegradation of BPA under long-wavelength light irradiation such as blue, green, and red light. In the photocatalytic conversion of sodium lignosulfonate (SL), the 0.05 HAPA-CN/PS system achieved a maximum yield of 134.34 mg/g SL vanillic acid at 30 min, which was significantly better than that of g-C 3 N 4. Synergistic gas production (H 2 , CO, CH 4 , C 2 H 4 , C 2 H 6) was also significantly enhanced. Combined with theoretical calculations, the mechanism was also analyzed. This work provides new insights for exploring high efficiency photocatalyst that combine porous structure, oxygen and phosphorus co-doping and PS activation technology for removal of organic pollutants and lignin valorization. [ABSTRACT FROM AUTHOR]

• The type-II heterostructured g-C 3 N 4 /ZnO NRAs films are synthesized via a light-assisted method. • A dense interface connection between g-C 3 N 4 and ZnO is achieved. • The heterostructured g-C 3 N 4 /ZnO NRAs films exhibit enhanced photocatalytic H 2 production. • The g-C 3 N 4 layer modification can inhibit ZnO photocorrosion. The type II heterostructured g-C 3 N 4 /ZnO nanorods arrays (NRAs) with intimate interface connection were successfully synthesized via a light-assisted method for photocatalytic H 2 production. Such type-II heterojunction between g-C 3 N 4 and ZnO not only promotes the charge separation and transport but also extends light absorption to the visible light region. In addition, the high physicochemical stability of g-C 3 N 4 layer keeps ZnO from photocorrosion during the reaction. Consequently, the heterostructured g-C 3 N 4 /ZnO NRAs demonstrate enhanced photocatalytic H 2 performance. In particular, the highest photocatalytic activity enhancement of g-C 3 N 4 /ZnO heterostructure is 3.3 times that of ZnO NRAs with a good stability of 85% retention rate after 5 cycles. Our work here presents an effective strategy to construct heterojunction between g-C 3 N 4 and metal oxide semiconductors for significantly enhanced photocatalytic H 2 production. [ABSTRACT FROM AUTHOR]

This paper presents a finite beam element method (FBEM) for analyzing the behavior of a two-pile foundation under eccentric and inclined loads located at sloping ground. A simplified physical model for the two-pile foundation is presented by dint of the strain wedge technique and FBEM. The emphasis is on establishing an element stiffness matrix, taking the P -Δ effect, the strengthening effect on the pile stiffness and the Pasternak's soil resistance into consideration. The global stiffness matrix can thus be assembled by these element stiffness matrixes, and the node force and deflection were identified by FBEM. The results are compared with field observations and exhibit satisfactory accuracy. [ABSTRACT FROM AUTHOR]

This study aims to develop a mounting-beams model predicting the behavior of geosynthetic reinforced and stone column-supported embankment with upper pavement under vehicle loads. Existing models are made a comparison with the proposed model, which can be deemed as their extension. Multiple factors, such as modified stiffness for tensionless granular mattress, the nonlinearity and consolidation of soft soils and the beam-soil interface resistance, are taken into account. On this basis, a parametric study is carried out to quantify the influence of bending stiffness of the upper pavement structure, the tensile stiffness of geosynthetic reinforcement, the vertical stiffness of a stone column wall, and the consolidation of soils on the response of the embankment system reinforced with geosynthetic and stone columns. [ABSTRACT FROM AUTHOR]

Adaptive finite element limit analysis (AFELA) is employed to investigate the stability of two circular tunnels at different depths in cohesive-frictional soils subjected to surcharge loading. The upper and lower bounds of the tunnel stability numbers are obtained, with the relative errors being found within ±5%. Five parametric studies are conducted to evaluate the effects of the horizontal and vertical spacing ratio, overburden stress factor, cover depth ratio and soil internal friction angle on the tunnel stability numbers. Design tables and charts are provided to facilitate engineers' use. In addition, typical failure mechanisms are discussed and examined. [ABSTRACT FROM AUTHOR]

Abstract This paper investigates the stability of dual circular tunnels in a rock mass subjected to surcharge loading using adaptive finite element limit analysis (AFELA). The tunnels are modelled under plain-strain conditions, and the rock mass is assumed to be a homogeneous and isotropic material obeying the Hoek-Brown failure criterion. For the studied problem, numerical kinematic and static approaches are employed to calculate the rigorous upper and lower bounds of the stability number N , which has been bracketed within ±5% from above and below. The calculated results are presented in the form of dimensionless stability charts, and the typical failure mechanisms are discussed through parametric studies of the problem variables using the visualized results of AFELA. [ABSTRACT FROM AUTHOR]

Abstract This paper proposes a modified strain wedge model for the analysis of laterally loaded piles in sloping ground. The proposed model allows the assessment of the soil resistance along the pile and describes the stress-strain behaviour of the soils using a nonlinear stress-strain model. The modified strain wedge is divided into two parts: an upper soil wedge and a modified lower strain wedge. Two calculation methods for the two parts are discussed, and an in-situ test is used to verify the validity and accuracy of the proposed method. [ABSTRACT FROM AUTHOR]

Recovery of natural vegetation is an effective but slow approach to control the soil erosion in the Chinese hill and gully Loess Plateau region. As seed stage is particularly vulnerable to environmental conditions, characteristics of seed population should be needed to study for determining whether the recovery of natural vegetation is limited during this stage on the abandoned slopes in this region. The study was performed on three abandoned slopes in a watershed with an area of 8.27 km 2 in the Shaanxi province of China. The differences in soil seed banks were investigated in two different points in time, late March 2011 and early April 2013. Main factors of seed population dynamics, such as seed yield of dominant species, seed inputs by seed rain as well as seed outputs through seed loss by overland flow and seedling emergence, were monitored from late March 2011 to early April 2013. In this study, seed rain densities of the main later successional species, i.e., Lespedeza davurica (Laxm.) Schindl., Stipa bungeana Trin. and Artemisia gmelinii Web. ex Stechm., accounted for 51.5–71.6% of their own seed yields. The soil seed bank density in early April 2013 was larger than that in late March 2011. The density of seed inputs by seed rain was 10186 seeds m −2 , and the total seed bank, including seed rain and seeds present in the soil seed bank in late March 2011, reached a density of 15018 seeds m −2 during the study period. Seed densities of loss duo to overland flow and seedling emergence were 79 seeds m −2 from 20 species and 938 seedlings m −2 that belonged to 38 species during a study period, and the seed output through them accounted for 0.5% and 6.3% of the total seed bank, respectively. The study concluded that overland flow could not result in large numbers of seeds loss and seeds were accumulating in the soil seed bank due to seed rain, and vegetation succession might be limited by curbed spatial seed dispersal and seedling establishment. [ABSTRACT FROM AUTHOR]

Herein, we report on a 3D MoS x /Zn 3 In 2 S 6 nanoflower for efficient photocatalytic selective oxidation of benzyl alcohol (BA) to benzaldehyde (BAD) (100 % conversion and 96.18 % selectivity in 1 h) with simultaneous H 2 coproduction. The experimental results, in combination with DFT calculations, reveal that MoS x not only endows photothermal properties of the composite but also acts as an electron transport bridge promoting photogenerated charge transfer, which in turn promotes the extraction of C α -H to produce H 2. MoS x /Zn 3 In 2 S 6 also demonstrated strong ability to selectively oxidize a lignin model compound, 2-phenoxy-1-phenylethanol (PP-ol), to 2-phenoxyacetophenone (PP-one) with H 2 coproduction. When incorporated with peroxydisulfate (PDS) for organic pollutant degradation, the MoS x /Zn 3 In 2 S 6 showed exceptional efficiency with 99.51 % removal of 2-mercaptobenzothiazole (MBT) in 20 min. This is attributed to Mo4+/Mo5+/Mo6+ redox interactions that activate PDS and promote generation of reactive oxygen radicals. This work provides a feasible strategy to design photocatalyst for biomass valorization and organic pollutants degradation. [Display omitted] • MoS x endows the photothermal properties of 3D MoS x /Zn 3 In 2 S 6 nanoflower. • DFT provides evidence and guidance for the electrons transfer pathway of MoS x. • MoS x promotes the extraction of C α -H to produce H 2. • 3D MoS x /Zn 3 In 2 S 6 nanoflower acts efficiently for real biomass photoreforming. • The Mo4+/Mo5+/Mo6+ redox interactions enhance the degradation of MBT. [ABSTRACT FROM AUTHOR]

Recently, biomass carbon materials as electromagnetic wave-absorbing materials have received widespread attention due to their easy availability, low cost, and environmental friendliness. However, for the vast majority of microwave absorbing materials that possess only dielectric losses, it is difficult for them to achieve satisfactory microwave absorbing performance. This paper proposes a new strategy to prepare a magnetic biomass composite material with tunable high-performance microwave absorption using agaric as the biomass carbon precursor and ferric nitrate as the magnetic precursor. When the carbonization temperature is 800 °C, the Fe/Fe 3 O 4 /biomass carbon (Fe/Fe 3 O 4 /BC) composite exhibits excellent microwave absorption performance in the X-band. At a thickness of 2.06 mm and a frequency of 9.63 GHz, its minimum reflection loss reaches −30.41 dB, and the effective absorption bandwidth is 2.45 GHz. In the carbonization process, ferric nitrate is transformed into magnetic Fe 3 O 4 and Fe nanoparticles. The magnetic losses generated by Fe/Fe 3 O 4 and the dielectric losses of biomass carbon, interfacial polarization, dipole polarization and multiple reflection synergies improve the impedance matching characteristics of the composite and improve the microwave absorption performance. Therefore, the prepared Fe/Fe 3 O 4 /BC composite material has exhibits great potential as a high-efficiency microwave absorber. [Display omitted] • Fe/Fe 3 O 4 /BC composites were prepared by a simple direct carbonization method. • Biomass carbon source agaric has the characteristics of wide source, low price and good structural stability. • The preparation process of the Fe/Fe 3 O 4 /BC composites is simple and can be produced in large quantities. • The Fe/Fe 3 O 4 /BC composites exhibit excellent microwave absorption properties in the X-band. [ABSTRACT FROM AUTHOR]

Rational design of all-solid-state Z-scheme heterojunction with advanced structure is essential for boosting photocatalytic efficiency. Herein, we design and fabricate a novel Z-scheme photocatalyst with leaf architecture (named artificial leaf) via a simple dipping-calcination (DC) process followed by a successive ionic layer adsorption and reaction (SILAR) strategy. The prepared artificial leaf, composing of CdS, InVO 4 , and BiVO 4 , holds advanced leaf-like structure and Z-scheme electron transfer pathway. As a result, this novel artificial leaf exhibits outstanding capability for the harvesting of visible light and superior efficiency for the separation of photogenerated electron-hole pairs, as well as remarkably enhanced photocatalytic performance and stability for H 2 evolution (with the rate of 5033 μm g−1∙h−1) and pollution degradation (46% pollution can be degraded within 3 h). [Display omitted] • Artificial leaf CdS–BiVO 4 –InVO 4 Z-scheme heterojunction system was synthesized. • Artificial leaf CdS–BiVO 4 –InVO 4 holds advanced leaf-like structure and Z-scheme electron transfer pathway. • Artificial leaf CdS–BiVO 4 –InVO 4 shows outstanding capability for visible light harvesting and carrier separation. • Artificial leaf CdS–BiVO 4 –InVO 4 exhibits an excellent photocatalytic activity for H 2 production and degradation of pollutants. [ABSTRACT FROM AUTHOR]

For Fe-based Fischer-Tropsch synthesis catalyst, how to decrease CO 2 formation is a big challenge. In this work, a capsule catalyst (FeMn@HZSM-5) with FeMn as core and HZSM-5 as shell was prepared and used for Fischer-Tropsch to olefins (FTO) reaction, compared with bare FeMn catalyst and several hybrid catalysts by physically mixing FeMn and HZSM-5 in different ways. Among these catalysts, the FeMn@HZSM-5 capsule catalyst showed the best catalytic performance with the highest light olefins selectivity and the lowest CO 2 selectivity. Compared with FeMn catalyst, the CO 2 selectivity of FeMn@HZSM-5 catalyst decreased more than 10%. However, the CO 2 selectivity of other physically mixing catalysts was similar to that of bare FeMn catalyst, indicating that randomly adding HZSM-5 had no effect on depressing the CO 2 formation. Benefiting from the HZSM-5 shell, the FeMn@HZSM-5 capsule catalyst could effectively affect the diffusion of H 2 O and thus suppress the water-gas shift reaction in FTO reaction. [Display omitted] • A capsule catalyst with FeMn as core and HZSM-5 as shell was used for FTO reaction. • Compared with FeMn, the CO 2 selectivity of FeMn@HZSM-5 decreased more than 10%. • The HZSM-5 shell structure suppresses the water-gas shift reaction in FTO reaction. [ABSTRACT FROM AUTHOR]