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ASCT2 (alanine serine cysteine transporter 2), a member of the solute carrier 1 family, mediates Na+-dependent exchange of small neutral amino acids across cell membranes. ASCT2 was shown to be highly expressed in tumor cells, making it a promising target for anticancer therapies. In this study, we explored the binding mechanism of the high-affinity competitive inhibitor L-cis hydroxyproline biphenyl ester (Lc-BPE) with ASCT2, using electrophysiological and rapid kinetic methods. Our investigations reveal that Lc-BPE binding requires one or two Na+ ions initially bound to the apo-transporter with high affinity, with Na1 site occupancy being more critical for inhibitor binding. In contrast to the amino acid substrate bound form, the final, third Na+ ion cannot bind, due to distortion of its binding site (Na2), thus preventing the formation of a translocation-competent complex. Based on the rapid kinetic analysis, the application of Lc-BPE generated outward transient currents, indicating that despite its net neutral nature, the binding of Lc-BPE in ASCT2 is weakly electrogenic, most likely because of asymmetric charge distribution within the amino acid moiety of the inhibitor. The preincubation with Lc-BPE also led to a decrease of the turnover rate of substrate exchange and a delay in the activation of substrate-induced anion current, indicating relatively slow Lc-BPE dissociation kinetics. Overall, our results provide new insight into the mechanism of binding of a prototypical competitive inhibitor to the ASCT transporters. [ABSTRACT FROM AUTHOR]

[Display omitted] • Perturbing O-antigen ligation shortened the resuscitating lag phase. • Higher ATP levels of Δ rfaL VBNC cells promote resuscitation. • ATP consumption during lag phase was highly correlated with resuscitation efficiency. • ATP was utilized to activate the Handler and salvage pathways to synthesize NAD+. • VBNC cells using residual ATP recover metabolic activity, driving cells to exit dormancy. Entry into the viable but nonculturable (VBNC) state is a survival strategy adopted by bacteria to survive harsh environment. Although VBNC cells still have metabolic activity, they lose the ability to form colonies on nonselective culture media. Thus, conventional bacterial detection methods, such as plate counting, are unable to detect the presence of VBNC cells. When the environmental conditions are appropriate, VBNC cells can initiate resuscitation, posing a great risk to the safety of public health. The study of the VBNC resuscitation mechanism could provide new insights into the prevention and control of VBNC resuscitation. Uncovering the molecular mechanism of VBNC cell resuscitation by investigating the role of O-antigen ligase (RfaL) in inhibiting the resuscitation of Escherichia coli O157:H7 in the VBNC state. RfaL was screened and verified as a resuscitation inhibitor of VBNC Escherichia coli O157:H7 by detecting resuscitation curve and time-lapse microscopy. The mechanism of RfaL impacts VBNC E. coli resuscitation was investigated by detecting the single cell ATP content, metabolomic changes, NAD(H) content and new protein biosynthesis of WT and Δ rfaL at different stage of resuscitation. Mutation of rfaL , which encoded an O-antigen ligase, markedly shortened the resuscitating lag phase. Further studies indicated that Δ rfaL VBNC cells contained higher ATP levels, and ATP consumption during the resuscitating lag phase was highly correlated with resuscitation efficiency. Metabolomic analysis revealed that ATP was utilized to activate the Handler and salvage pathways to synthesize NAD+, balancing redox reactions to recover cell activity and promote cell resuscitation. Our findings revealed a strategy employed by VBNC cells for revival, that is, using residual ATP to primarily recover metabolic activity, driving cells to exit dormancy. The synthesis pathway of lipopolysaccharide (LPS) in rfaL null mutant was inhibited and could supply more ATP to synthesis NAD+ and promote resuscitation. [ABSTRACT FROM AUTHOR]

Triethanolamine (TEA) has been broadly used as the organic amine conditioning agent to modify the workability of cement-based materials. However, the effect of TEA on the structure and property of porous silicate cement membranes has not been reported. In this paper, TEA was applied to study its effect on parameters of porous silicate cement membranes based on the preparation method combining freeze casting and heat-dry curing, because it is easy to form complexes with cement particles. The effect and acting mechanism of TEA on porous silicate cement membranes were researched using a series of characterizations and molecular dynamics (MD) simulation. Results showed that TEA significantly improved the performance of porous silicate cement membranes. The addition of TEA changed the pore morphology of porous silicate cement membranes from lamellar structures to cellular structures, with mesoporous size distribution focusing on 2.5–4.5 nm at TEA doping ratio of 0.16 wt%. The oil-water separation performance could reach up to 99.6 %. Through comprehensive comparison, the porous silicate cement membrane with 1.0 wt% TEA showed better holistic preponderance of oil-water separation and permeation flux. Quantum chemistry calculation and MD simulation were used to briefly explain the influence of TEA on phase transformation. MD showed that adding TEA changed the morphology and structure of ice crystals. The percentage of the Ih structure significantly increased from 53 % to 86 % after adding TEA. This study might expand the application of TEA in other aspects and enlighten relevant workers in new experimental designs. [Display omitted] • TEA noticeably changed the pore morphology form lamellar to cellular structures. • Cement membranes doped TEA showed excellent separation performance and stability. • Effects of TEA on crystals were analyzed via quantum chemistry and MD simulation. [ABSTRACT FROM AUTHOR]

Preparation of porous cement-based materials via freeze casting is a process with great potential. However, freeze-drying and steam curing complicate the preparation process and increase the preparation period. To simplify the process, heat-dry curing was used for replacing freeze-drying and steam curing during operation. The new preparation method combined freeze casting and heat-dry curing possesses characteristics of low-energy, simplicity, and time-saving. Compared with the traditional preparation method of porous cement-based materials, the novel preparation process can shorten preparation time by at least 16 % and retrench energy consumption by at least 18 %. As the improvement condition, temperature of heat-drying curing has great influence on the structure and performance of the samples. Therefore, it is of great significance to discuss the relationship between heat-dry temperatures and structural parameters by SEM, N 2 -adsorption/desorption, TG, and ATR-FTIR. Lamellar pores of membranes can be easier observed at low temperatures than that at 100 °C. The separation performance of oil-water is generally improved with the increase of temperature. Meanwhile, the molecular dynamics simulation was operated to illustrate the reaction mechanism of hydration with three temperatures. This study probably provides more theoretical basis for expanding the application of porous silicate cement membranes. [Display omitted] • Novel coupled method simplifies the fabricating process complexity of cement-based samples. • Influences of heat-dry curing temperatures on porous silicate cement membranes are discussed. • Silicate cement membranes own excellent permeation, oil-water separation and mechanical strengths. • Influences of heat-dry curing temperatures are illustrated by using molecular dynamics. [ABSTRACT FROM AUTHOR]

Preparation of porous cement-based materials via freeze casting is a process with great potential. However, freeze-drying and steam curing complicate the preparation process and increase the preparation period. To simplify the process, heat-dry curing was used for replacing freeze-drying and steam curing during operation. The new preparation method combined freeze casting and heat-dry curing possesses characteristics of low-energy, simplicity, and time-saving. Compared with the traditional preparation method of porous cement-based materials, the novel preparation process can shorten preparation time by at least 16 % and retrench energy consumption by at least 18 %. As the improvement condition, temperature of heat-drying curing has great influence on the structure and performance of the samples. Therefore, it is of great significance to discuss the relationship between heat-dry temperatures and structural parameters by SEM, N 2 -adsorption/desorption, TG, and ATR-FTIR. Lamellar pores of membranes can be easier observed at low temperatures than that at 100 °C. The separation performance of oil-water is generally improved with the increase of temperature. Meanwhile, the molecular dynamics simulation was operated to illustrate the reaction mechanism of hydration with three temperatures. This study probably provides more theoretical basis for expanding the application of porous silicate cement membranes. [Display omitted] • Novel coupled method simplifies the fabricating process complexity of cement-based samples. • Influences of heat-dry curing temperatures on porous silicate cement membranes are discussed. • Silicate cement membranes own excellent permeation, oil-water separation and mechanical strengths. • Influences of heat-dry curing temperatures are illustrated by using molecular dynamics. [ABSTRACT FROM AUTHOR]

BNT-6BT-based lead-free ceramics have gained significant attention due to their relatively large piezoelectric coefficients and tunable morphotropic phase boundary conditions. In this investigation, SrTiO 3 (ST) was added to BNT-6BT ceramics to fabricate the BNT-6BT- x ST (BNBT- x ST) composition. The impact of ST content on the phase structure and dielectric permittivity of the BNBT- x ST ceramics was studied. The XRD refinement data show that with increasing ST content, the crystal structure of BNBT- x ST ceramics was transformed from the morphotropic phase structure (coexisting tetragonal (P4/mmm) and pseudo-cubic (Pmm) phase) to the pseudo-cubic phase. The dielectric permittivity data of the BNBT-80ST showed that the T m (the maximum permittivity temperature) moved to −61.9 °C, which caused the room temperature to fall within the range of T m < T < T B (the Burns temperature). This makes the BNBT-80ST a superparaelectric state in relaxor ferroelectrics (RFE). Furthermore, the maximum energy density and the charge-discharge efficiency of the BNBT-80ST achieved 5.48 J/cm3 and 87% at 495 kV/cm, respectively. The energy density of the BNBT-80ST was improved by 2.97-fold and 49% compared with that of the BNBT-30ST and BNBT-70ST. This is mostly attributed to weakened ferroelectricity and improved paraelectricity in the BNBT-80ST. This investigation demonstrates that BNBT- x ST ceramics can be adjusted to a superparaelectric state with an ST content of 80%. This makes the material to possess both a large polarization and a high breakdown field. This material holds great promise for high energy density capacitor applications. [ABSTRACT FROM AUTHOR]

This study investigated the effect of local structural coupling between the buffer and the superconducting layers on the superconductivity of a GdBa 2 Cu 3 O 7-x (GdBCO)/La 0.7 Sr 0.3 MnO 3 (LSMO) bilayer. Epitaxial bilayers consisting of GdBCO with varying thicknesses (100, 300, and 500 nm), with and without LSMO (100 nm), were fabricated on a (001) SrTiO 3 substrate. To investigate the local structural distortion within the GdBCO/LSMO system, the temperature-dependent extended X-ray absorption fine structure (EXAFS) spectra were measured at the Mn- and Cu–K absorption edges. The EXAFS analyses revealed local structural non-uniformity, which manifested as anomalies in the temperature dependence of both the Mn–O and Cu–O bond distributions. A strong correlation exists between the local structural distortion of the Mn–O bond and the degree of lattice instability in the CuO 2 plane, which exhibits a strong thickness dependence. The inter-atomic potential of oxygen oscillations with an anharmonic approximation was adopted to interpret the structural anomalies. As a result, a double-well potential was obtained near T c , owing to the occurrence of longer Cu–O bonds in the CuO 2 plane. The difference in the degree of structural anomalies depending on the GdBCO thickness manifested as a difference in the distance between the two wells, which closely correlates with the appearance of a superconducting state. These experimental results demonstrate the role of local lattice fluctuations in the superconducting mechanism of the GdBCO/LSMO bilayer. [ABSTRACT FROM AUTHOR]

A direct joining of sapphire and Fe–36Ni alloy was successfully realized via femtosecond laser micro-welding for the first time. A sound joint without any voids or microcracks was obtained with a narrow interface width less than 1 μm. There was no obvious element diffusion or metallurgical reactions at the interface. Sapphire and Fe–36Ni alloy were found chemically bonded and mechanically interlocked evidenced by jagged feature at the interface due to "cold" machining of femtosecond laser ablation. The highly localized femtosecond laser irradiation and smaller heat-affected zone contributed to the shear strength of the joint as high as 108.35 MPa. A higher laser scanning speed corresponded with less jagged feature and thermal stress due to the reduced thermal deposition at the interface. Proper micro-welding parameters were obtained for sapphire/Fe–36Ni alloy, and was verified in the direct joining of sapphire/steel and sapphire/silicon. It appears the femtosecond laser micro-welding technique is promising for direct joining of materials with large physical property disparities, and beneficial for manufacturing of optomechanical components at high precision, efficiency and performance. [ABSTRACT FROM AUTHOR]

Porous silicate cement membranes (PSCMs) fabricated by the freeze casting method show great potential to be utilized in seawater pretreatment, fermentation broth separation, and industrial wastewater treatment due to its merit of high-temperature resistance, low-cost, and hierarchically ordered porous structures, while the freeze casting method is complex and time-consuming. In this work, a combination of freeze casting and heat-dry curing was initially applied to generate PSCMs. The preparation periods of PSCMs could be shortened by simplifying preparation processes and reducing curing time. The resulting membranes presented double-layer structures, containing a nucleation zone (N-zone) with dense structures and a stability zone (S-zone) with lamellar pore structures. The X-ray diffraction pattern of membranes displayed the mixed hexagonal and rhombohedral structures. This novel method could save more than half of energy consumption compared with the traditional preparation technology of silicate cement samples. The membranes with a mesopore size of 3.794 nm showed high permeation performance with pure water flux reaching 207.23 L m−2 h−1 under 0.15 MPa and room temperature. The separation efficiency of oil-water was 78.05% under operating pressure of 0.05 MPa. Molecular dynamics simulation was applied to narrate the microscopic process of transformation during heat-dry curing, and obtained a good similarity of consequences between the computational method simulation and experimental operation. [Display omitted] • Freeze casting combined with heat-dry curing to fabricate porous silicate cement membrane. • Freeze drying and steam curing were replaced using heat-dry curing. • Porous silicate cement membranes showed lamellar porous structures. • Molecular dynamics simulation was used to elucidate the hydration process of heat-dry curing. [ABSTRACT FROM AUTHOR]

In order to gain insight into how the addition of Cu element affects the crystallization mechanism of amorphous nanocrystalline alloys and soft magnetic properties, the crystallization behavior of (Fe 0.83 B 0.11 Si 0.02 P 0.03 C 0.01) 100-x Cu x (x = 0 and 0.5) amorphous ribbons was investigated based on kinetic and thermodynamic behavior under non-isothermal and isothermal annealing conditions. The results show that under non-isothermal annealing conditions, the Cu0.5 amorphous ribbon not only favors the formation of the amorphous structure, but also enlarges the temperature window for annealing and improves the thermal stability of the α-Fe(Si) phase. At the same time, the Cu0.5 amorphous ribbon shows slow kinetic and is insensitive to heating rate change during annealing treatment. Under isothermal conditions, the addition of Cu decreases the nucleation activation energy (E n) and increases the growth activation energy (E g). This further indicates that the nucleation of α-Fe(Si) grains is easier than the growth process, which is conducive to the formation of a homogeneous nanostructure and improves the soft magnetic properties of the alloy. Compared to Cu0 amorphous ribbon, it is also shown that the Cu0.5 amorphous ribbon changes the crystallization mechanism from diffusion-controlled one-dimensional to two-dimensional growth when the crystallization volume fraction x is 10–30 vol%. While three-dimensional growth become dominated when x is reaches 60 vol% for both ribbons. Therefore, the kinetics of crystallization as well as microstructure supports that the Cu0.5 ribbon is able to exhibit uniformly fine nanocrystalline structures. Further, the Cu0.5 nanocrystalline ribbon shows a higher B s of 1.85 T and a lower H c of 2.55 A/m, respectively, and the favorable (100) orientation of α-Fe(Si) grains formed after annealing is another factor to increase B s. • The Cu-containing alloy show kinetic insensitivity and is suitable for a high heating rate. • The addition of Cu changes the crystallization mechanism when x is between 10% and 30%. • When the applied magnetic field is ND, precipitation of (100) orientation α-Fe grains favors enhancing B s. • The Cu0.5 alloy show B s of 1.85 T, H c of 2.55 A/m. [ABSTRACT FROM AUTHOR]

Dual-state (solution and solid) highly emissive three-arm star polymethacrylates were synthesized via ATRP using TPA-BKI-3Br as initiator. [Display omitted] • Three-arm star polymethacrylates with bright luminescence in both solution and solid state were prepared and studied efficiently. • The photophysical characteristics of the polymethacrylates were notably impacted by the space charge transfer between the TPA-BKI unit and polymer chains. Organic/polymeric fluorescent materials with bright emission both in solution and in the solid state have garnered growing interest in biological and optoelectronic fields. Herein, triphenylamine-derived boron ketoimine (TPA-BKI-3Br) was utilized as the initiator for atom transfer radical polymerization (ATRP) to prepare dual-state emission three-arm star polymethacrylates. Due to the intramolecular charge transfer (ICT) effect and highly distorted structure of the TPA-BKI unit, as well as the polymer arms constraining intramolecular motions, the resultant polymers displayed significant emission in solution. In the aggregated and solid states, the photophysical characteristics of the resultant polymethacrylates were notably impacted by the space charge transfer between the TPA-BKI unit and polymer chains. In addition, the TPA-BKI-based poly(2-(dimethylamino)ethyl methacrylate) (TPA-BKI-(PDMAEMA)3) exhibited fluorescence responses to temperature variations owing to the presence of dimethylamino group. This study presents an approach for the advancement of dual-state emission polymeric materials. [ABSTRACT FROM AUTHOR]

Two complexes based on phosphorescent viologen ligands have been synthesized. Complexes 1 and 2 not only possess reversible photochromic and electrochromic properties, but also exhibit fluorescence and persistent luminescence. They have potential applications in inkless print, color-changing films, data encryption, and anti-counterfeiting. [Display omitted] • Complexes 1 and 2 exhibit reversible photochromic and electrochromic behaviors. • Complexes 1 and 2 exhibit long-lived persistent phosphorescence. • Complexes show great potential in data encryption and anticounterfeiting. • Complexes have potential applications in inkless printing, color-changing films. Viologen-based complexes have garnered significant attention due to their multifunctional stimuli-responsive properties and tunable persistent luminescence. However, achieving ultralong afterglow emission and color change in these complexes remains a challenge, limiting their application in the field of persistent luminescence. Herein, two novel viologen-based complexes were successfully designed and synthesized using N,N′-bis(2-carboxyethyl)-4,4′-bipyridinium dichloride (H 2 bybpy) ligands and trimesic acid (H 3 BTC) with the transition metals Zn(II)/Cd(II). Complexes 1 and 2 display reversible photochromic and electrochromic properties. Interestingly, complexes 1 and 2 in their crystal state exhibit dual fluorescence and persistent luminescence, emitting a green and cyan afterglow when the UV lamp is turned off at 77 K. Incorporating phosphorescent molecules and changing the metal significantly extended the duration of persistent luminescence and altered the hue. The complexes were also demonstrated to have potential applications in inkless printing, color-changing films, data encryption, and anti-counterfeiting. This work enhances the application of viologen-based complexes in light-controlled persistent fluorescence and provides ideas for achieving ultra-long afterglow emission. [ABSTRACT FROM AUTHOR]

Damage or condition anomalies of stay cables will directly affect the safety of bridges in operation. As an important load type, the cyclic action of stochastic traffic flow (STF) is a main cause of cable performance degradation. However, due to its time-varying and complexity, there have been few studies on the anomaly diagnosis of stay cables under STF loading. Therefore, this paper proposes a novel condition monitoring method for stay cables based on the time-history area (THA) of cable forces under STF loading. First, mechanical analysis was performed to establish the theoretical relationship between THA and STF. The feature vector and matrix to characterize the normal condition of stay cables were developed based on the above relationship. Second, an online diagnosis model was established using the constant correlation between feature vector elements in the health state. On this basis, the Mahalanobis-squared distance (MSD) is employed to define an early warning index, which is used to inspect abnormal changes in cable performance. Third, according to numerical analysis, the rationality of the theoretical derivation was further confirmed and the feature vector variations in different simulated cases were presented. Finally, the effectiveness and practicability of the proposed method was verified on an actual cable-stayed bridge. The results demonstrate that the established online model has satisfactory diagnostic capabilities, which can accurately monitor the service condition of stay cables. • The relationship between THA and ILA of cable forces is revealed for the first time under complex STF. • An online diagnosis model is established to realize the condition monitoring of stay cables in operation. • The effectiveness and practicality is verified by numerical verification and case study of an actual bridge. • The method can be applied using only cable forces to ensure wider engineering applications. [ABSTRACT FROM AUTHOR]

The particular and homogeneous solutions of two-dimension (2D) thermal-elastic problems are expressed by using the virtual boundary element method (VBEM) and the superposition principle. Accordingly, two matrix equations are needed and formed for particular and homogeneous solutions by the novel nonsingular boundary element method with the radial basis function interpolation (RBFI), namely virtual boundary meshfree Galerkin method (VBMGM). Considering the boundary conditions of heat conduction and combining the Galerkin method, virtual source functions of particular solutions can be solved by first using VBMGM. Applying boundary conditions of transformation, virtual source functions of homogeneous solutions can be obtained by second employing VBMGM. The coefficients of two matrix equations are symmetrical. Formed equations are nonsingular and have merits of virtual boundary element method, meshfree method, and Galerkin method. The detailed expressions, calculation steps, and simplified flow chart are given in detail, that is convenient for other scholars to study other more complex thermo-elastic problems through the method of this paper. Three examples are calculated. Comparing their calculation results with other methods, the stability and the precision of VBMGM for 2D thermal-elastic problems are validated. [ABSTRACT FROM AUTHOR]

Fluid viscous dampers (FVDs) are the key energy dissipation devices for long-span suspension bridges, and their leakage poses a threat to the stable and reliable operation of bridge restraint systems. Therefore, this paper proposed an FVD fluid leakage diagnosis method based on girder longitudinal displacement monitoring data. First, the longitudinal vibration equation of the main girder under traffic loads was derived to reveal the displacement characteristic of girder-end motion. On this basis, considering that different displacement components under traffic loads are coupled and transient analysis directly utilizing traffic loads as the excitation is complicated and inefficient, an analysis framework focusing on the influence mechanism of FVD leakage on quasi-static displacement was established. Second, an equivalent mechanical model for simulating the hysteresis relationship of leaked FVD was proposed and verified. Then, the influence of variations in the location, number, leakage level and parameters of the leaked FVD on the quasi-static displacement was studied. Third, the equivalent traffic load (ETL) indicator was constructed to characterize the traffic volume. Furthermore, a quasi-static cumulative displacement and ETL correlation model, which can effectively eliminate the interference of traffic flow variations, was proposed for the leakage diagnosis of FVD. Finally, the proposed method was verified by real suspension bridge monitoring data. The results demonstrated that the proposed method can effectively detect a mild increase in the girder-end cumulative displacement due to FVD fluid leakage. • Proposed and validated an equivalent model for simulating the hysteresis relationship of leaked FVD. • The influence of leaked FVD locations, numbers, leakage levels and parameters on vehicle-induced GECD was revealed. • An online diagnosis method was established to realize the condition monitoring of FVD leakage in operation. • The effectiveness is verified by case study of an actual in-service suspension bridge. [ABSTRACT FROM AUTHOR]

Maritime transportation is the backbone of global trade, as ships carry over 80% of trading goods worldwide. As the shipping industry is mainly powered by heavy fuel oil, it has an adverse environmental footprint due to the emissions of greenhouse gases and polluting substances. To comply with IMO emission regulations and optimally save on fuel costs (which can account up for 50% to 60% of the total cost of operating a ship), shipping companies are motivated to optimize energy consumption. In this study, we first develop am innovative and tailored artificial neural network-based fuel consumption prediction model. This model innovates in that it explicitly considers shipping domain knowledge by modifying and optimizing its structure and parameters, where such properties have rigorously been proven. Moreover, it considers a broad range of influence factors based on data fusion technology. Next, we optimize the ship sailing speed profile for a bulk carrier in two application scenarios using the predicted fuel consumption rates by the proposed neural network-based model as the input: one is a bi-objective model, and the other considers market-based measures. Numerical experiments show that the proposed fuel consumption prediction model outperforms other models and that the model we propose can help to improve ship energy efficiency by a considerable extent. The proposed model conforms more closely to common sense than existing models; thus, it will likely have a better potential for use in the maritime industry and other problems with similar domain knowledge possessed. • Use data fusion to combine a wide scope of data sources into a single dataset for artificial neural network (ANN) model construction • Develop a tailored ANN model for ship energy consumption prediction considering monotonicity and convexity • The mean absolute percentage error of the developed ANN model is 7.5% • Develop ship sailing speed optimization models in various application scenarios • The proposed ANN model improves ship energy efficiency by 2% to 2.5% [ABSTRACT FROM AUTHOR]

• The simplified expression of bond potential in CBPD for isotropic linear elastic solids is clearly defined and validated. • An improved energy-based bond failure criterion by considering a bond energy distribution is proposed in CBPD to describe brittle fracture. • A stabilization technique to avoid the unexpected irregular damages is proposed in CBPD. • A direct coupling model of CBPD and FEM is established, and the ghost forces at the interface are negligible. • Several typical quasi-static and dynamic brittle fracture problems are accurately and stably predicted by the proposed method. Correspondence-based peridynamics (CBPD) is attractive and promising because of its outstanding ability to employ the traditional constitutive relations for material modeling. However, application of CBPD to brittle fracture problems is somewhat limited due to the numerical instability issue and lack of a rational bond failure criterion. To enable CBPD to accurately and stably predict brittle fracture problems, an improved energy-based bond failure criterion is firstly established in this work, in which the expression of bond potential is re-derived, and its simplified expression for isotropic linear elastic solids is clearly defined. The critical bond potential is determined by assuming it is directly proportional to the bond length, and the discretization error for the critical energy release rate in the discretized model is corrected with a correction factor. Besides the zero-energy mode control method, additional stabilization technique to reduce the influence of ill-posed or singular reference shape tensor on brittle fracture simulations is also explored to avoid the unexpected irregular damages during the fracture process. In addition, a direct coupling model of CBPD and FEM is established to improve the computational efficiency, and the ghost forces at the interface are verified to be negligible. Finally, several numerical examples involving typical quasi-static and dynamic brittle fracture problems are investigated, and fracture behaviors including the crack paths, load-displacement curves, and crack propagation speeds are all well predicted, which sufficiently demonstrates the accuracy and stability of the proposed method. [Display omitted] [ABSTRACT FROM AUTHOR]

Finite element model updating (FEMU) is a frequent method for minimizing the differences between actual and predicted bridge structural behavior. However, static model updating for long-span bridges usually requires load tests to obtain the response under known static loads, which is costly due to long traffic interruptions. To offset this disadvantage, a static FEMU method based on long-term monitoring data is proposed to update the model in real-time by taking stochastic traffic loads with certain statistical characteristics as known static loads. First, the theoretical relationship between stochastic traffic flow statistical characteristics, static response statistical characteristics, and structural stiffness parameters is established. An objective function based on the probability characteristics of the long-term vehicle-induced response is constructed. Then, the FEMU process based on monitoring data is introduced, including the acquisition of the finite element model vehicle-induced response, the extraction of the actual vehicle-induced response based on the monitoring data, the selection of model updating parameters, and the application of the global-local parameter updating optimization method. Finally, the effectiveness of the proposed method is verified by applying numerical examples and real bridge examples to a long-span suspension bridge. It can be concluded that the proposed method can achieve FEMU based on long-term monitoring data, avoiding the inconvenience and large cost caused by load tests. The accuracy and efficiency of the model updating can meet the engineering requirements well through comparison with the result of the traditional load test method. • This paper presents a static finite element model updating method based on the statistical characteristics of long-term monitoring data during normal operation, avoiding the inconvenience and large cost caused by the previous model updating method based on the load test. • The proposed method takes stochastic traffic load with known probability characteristics as known static load, and can realize model updating well by reducing the error of the actual response probability characteristics and finite element model prediction response probability characteristics. • The probabilistic characteristics of long-term vehicle-induced static response are related to structural stiffness parameters and probabilistic characteristics of stochastic traffic flow. When the probabilistic characteristics of stochastic traffic flow are the same, the static response probabilistic characteristics are related to only the structural stiffness parameters. [ABSTRACT FROM AUTHOR]

We investigated the effect of the thickness of superconducting layer on the competition between ferromagnetism and superconductivity. The epitaxial bilayer systems consisting of GdBa 2 Cu 3 O 7-x (GdBCO) with varying thickness and La 0.7 Sr 0.3 MnO 3 (LSMO) were grown on (001) SrTiO 3 (STO) substrate. From the spectroscopic measurements, we observed an existence of a possible structural coupling between the GdBCO and the LSMO layers. The structural coupling is found to depend on the GdBCO thickness and to induce different types of strain on both layers, leading to the competition between the ferromagnetic and the superconducting orders. With respect to the flux pinning, an additional pinning contribution besides magnetic pinning induced by LSMO is emerged by the structural coupling, which is attributed to local atomic disorder. Controlling the thickness of GdBCO modifies the structural coupling and consequently, the degree of additional pinning contribution aroused by disorder on the CuO 2 plane can be adjusted. An appropriate structure with a certain thickness amplifies the hybrid effect of magnetic pinning and additional pinning, resulting in an enhancement of the critical current density at high magnetic fields. Our findings suggest a possibility of controlling complex flux pinning through an optimization of structural coupling between the GdBCO and the LSMO layers. [ABSTRACT FROM AUTHOR]

Nitrogen-doped porous carbon possesses widespread applications in energy-related fields due to its unique properties. However, preparation of porous carbon (specific surface area > 3000 m2 g–1) with high nitrogen content (> 10 wt%) remains great challenges because of high synthesis temperature. Herein, a covalent triazine polymer was innovatively designed by cyclotrimerization of tetracyanoethylene, and used to produce the high nitrogen-doped porous carbon. The as-prepared porous carbon (HNPC-900) possesses a high nitrogen content (14.2 wt%) and large specific surface area (3210 m2 g–1). When HNPC-900 was applied as the air-cathode for zinc–air batteries, it shows a high specific capacity (797 mAh g zn –1) and stable rechargeability (more than 380 h over 960 cycles at 5 mA cm–2), outperforming the cathode composed of RuO 2 and 20 wt% Pt/C. This ingenious design provides a feasible strategy to prepare high nitrogen-doped porous carbon, giving extensive application prospects of porous carbon for catalysis and energy storage fields. [Display omitted] • Tetracyanoethylene is used for preparing a new covalent triazine polymer (CTP). • HNPC derived from CTP possesses dual-superiority in N content and porosity. • HNPC exhibits excellent bifunctional electrocatalytic performances. • HNPC shows the recyclable ability for zinc–air battery. [ABSTRACT FROM AUTHOR]

Crystal and electronic structures, and magnetic properties of polycrystalline tantalum substituted manganites CaMn 1- x Ta x O 3 (x = 0.00, 0.03, 0.06, 0.09 and 0.12) were studied by x-ray diffraction, x-ray absorption near edge spectroscopy (XANES) at Mn K -edge, and by magnetization measurements. Large changes of cell volume and magnetic transition temperature, in addition to shift of Mn K -edge spectra and change of shape of XANES spectra, indicate the existence of Mn3+ as well as Mn2+ species induced by the substitution of Mn4+ by Ta5+. Cell parameters and cell volume increase with increasing x because the Mn3+, Mn2+ and Ta5+ ions are larger that substituted Mn4+ ion. According to XANES results, at least the x = 0.00 sample is oxygen deficient. The negative magnetization was observed in the CaMnO 3-δ sample, and a possible explanation of the phenomenon is given considering two canted (almost antiferro)magnetic sublattices and a shielding current, associated with the itinerant e g electrons, induced by the oxygen vacancies. • Negative magnetization (NM) and divalent manganese are observed in CaMn 1−x Ta x O 3-δ. • NM caused by canted antiferromagnetic (AFM) states and e g electron shielding current. • AFM state and shielding current originate from Ta- and/or oxygen vacancy- content. • Large decrease in T C and change in shape of XANES spectra due to Mn2+ are observed. [ABSTRACT FROM AUTHOR]

A Mott-Schottky heterojunction is reported to boost the peroxymonosulfate (PMS) activation in Fenton-like reaction through a non-radical path. The heterojunction with Co nanoparticles encapsulated by nitrogen-doped graphitized carbon (N-GC) shell was synthesized via pyrolysis of ZIF67 @ZIF8 and subsequent acidic treatment. Benefiting from Mott-Schottky effect, the electrons were transferred from Co nanoparticles to the N-GC shell, leading to the rearranged electron density on N-GC surface and improvement of the PMS activation. The PMS activation efficiency of heterojunction (86.0%) was much higher than the reference catalyst without Mott-Schottky effect (35.3%), and even comparable to Co2+ (86.2%). 85.0% of tetracycline (TC) removal efficiency was realized after only 10.0 s. Moreover, the intrinsic advantages of non-radical path were well inherited by Mott-Schottky heterojunction, including high anti-interfere property toward various anions, cations and organics, high catalytic activity in a wide pH range, low metal leaching, and high magnetic recyclability. [Display omitted] • Electrons flow from Co NPs to N-GC and arranged in Mott-Schottky heterojunction. • PMS activation efficiency is comparable to Co2+ and 85.0% of TC is removed at 10 s. • Electrons play crucial role among ROSs, and PMS activation follows non-radical path. • Mechanism of Mott-Schottky effect on enhanced degradation performance is revealed. • EP-ZIF67 @ZIF8 is high environmental adaption, wide applicable pH, low leaching. [ABSTRACT FROM AUTHOR]

Solutions of 3D thermal analysis in inhomogeneous media with variable thermal source are divided into homogeneous and particular solutions by a novel boundary-type element-free method, namely virtual boundary element-free Galerkin method (VBEFGM). The homogeneous solution can be obtained by the virtual boundary element-free method (VBEFM). The virtual source function of the homogeneous solution and the unknown coefficient of the particular solution are constructed by the radial basis function interpolation (RBFI). And VBEFGM for 3D thermal analysis in inhomogeneous media with variable thermal source is real meshfree and does not require the background integral element. Its equation is obtained the Galerkin method of the weighted residual methods. The demonstration of ANSYS Parametric Design Language (APDL) can greatly facilitate the programming for the extraction of the coordinate information and the outer normal cosines on nodes. The calculation scheme and the specific weighted coefficients are deducted in detail for 3D thermal analysis in inhomogeneous media with variable thermal source by VBEFGM. The numerical calculational steps and flow chart are given. Three numerical examples are computed. The results are compared with other numerical methods and the exact solutions. The stability and the accuracy of the proposed method is proved by VBEFGM for 3D thermal analysis in inhomogeneous media with variable thermal source. [ABSTRACT FROM AUTHOR]

InGaN/GaN micro-crystals (μ-crystals) are self-contained and individually-addressable light emitting crystals that have unique potential in the development of ultra-small and ultra-high resolution pixels for next-generation displays. In this study, we explore the electrically-driven light emission behavior of vertically standing InGaN/GaN micro-crystals (μ-crystals) with well-defined crystal facets and tunable size. InGaN/GaN μ-crystals have hollow pedestals weakly bound to the substrate surface, thus enabling individual manipulation and/or collective transfer to other target surfaces. Cyclic bending tests and finite element analysis (FEA) of the strain distribution further highlight the excellent mechanical deformability of a device layout consisting of μ-crystal pixels embedded in a polymeric matrix. Light-emitting diodes (LEDs) with individual InGaN/GaN μ-crystals exhibit strong electroluminescence (EL) with unique features such as variations in emission spectra with respect to crystal diameter and driving voltage bias. Comparative analyses of photoluminescence, cathodoluminescence, and electric potential simulation indicate a strong correlation between the EL wavelengths and dominant emitting regions of InGaN/GaN polyhedral crystal planes. This is further supported by scanning transmission electron microscopy of quantum well structures, which strongly depend on both size and the crystal facets. • Self-contained InGaN/GaN MQW micro-crystal arrays are employed as light emitting pixels on a deformable substrate. • The μ-crystal LEDs exhibit a variation of emission spectra with respect to the crystal diameter and driving voltage bias. • Optoelectrical and structural analysis of InGaN/GaN μ-crystal LEDs reveals the multicolor emission mechanism. [ABSTRACT FROM AUTHOR]

An NDI-based compound (2-NDI) with 2-butyric acid attached at imide N atoms was intelligently constructed. 2-NDI exhibits 2-NDI − monomer (low concentration) and 2-NDI − excimer (high concentration) emission state in different solvents after 365 nm illumination, forming multi-color radical fluorescence. It shows dynamic free radical emission in DMF solvent with rare white light emission. Theoretical calculations show that the fluorescence is derived from the D n -D 0 vertical emission of 2-NDI − monomer and 2-NDI − excimer. Finally, 2-NDI is made into PMMA film, which is successfully applied to information anti-counterfeiting and dynamic information encryption systems. [Display omitted] • 2-NDI was synthesized and showed different free radical emission colors in different solvents. • The dynamic fluorescence of 2-NDI in DMF solution changed with the irradiation time. • 2-NDI shows different free radical fluorescence emission types at different concentrations. • DFT shows that the free radical fluorescence is the vertical emission of D n -D 0. • 2-NDI PMMA film can be used for dynamic information encryption and anti-counterfeiting. Developing innovative materials with environmentally stable 1,4,5,8-Naphthalene diimide radicals (NDI −) emissions is significant. In this work, we have successfully constructed an NDI-based material 2-NDI (N, N′-bis(2-butyric acid)-1,4,5,8-naphthalene diimide) that emits strong fluorescence in solvents and polymethyl methacrylate (PMMA) upon irradiation. The radical 2-NDI − exhibits multi-color emission in different solvent systems, and the fluorescence emission is concentration-dependent. It is worth noting that it exhibits a rare dynamic fluorescence in DMF solvent, with the fluorescence color changing from yellow-green to orange and finally to white. Theoretical calculations show that the fluorescence is derived from the D n -D 0 vertical emission of 2-NDI − monomer and excimer. Owing to the outstanding free radical fluorescence emission properties, various films (PMMA systems) based on 2-NDI in different solvents have been successfully made to be applied in multiple dynamic information anti-counterfeiting and encryption. This work achieved simple and stable fluorescence emission based on NDI −, making it a potential candidate for practical applications and providing a new platform for the future design of NDI-based photochromic materials. [ABSTRACT FROM AUTHOR]

• The theoretical relationship between the vehicle load and vehicle-induced cable force sums (VICFS) is derived through mechanical analysis and the specific expression is given for the first time. • An anomaly-sensitive warning index that directly reflects the service performance of stay cables is established based on the derived theoretical relationship and the detailed calculation procedures are given in this paper. • A new anomaly diagnosis method for stay cables is proposed by combining the established warning index with the X-bar control chart to solve the complex analysis problems caused by the transverse position of the vehicle on the bridge deck. • A new cable force decoupling method based on local generalized extreme value (GEV) distribution is presented to eliminate temperature trends from the raw data and obtain VICFS dataset. • The numerical simulations and an engineering application to an in-service cable-stayed bridge are carried out to verify the feasibility and effectiveness of the proposed method. Stay cables are one of the most critical load-carrying components for cable-stayed bridges. Cable damage or performance degradation can affect the normal operation of bridges. Therefore, it is essential to evaluate the service performance of cables in real time to ensure bridge safety. In this paper, an anomaly diagnosis method for stay cables based on vehicle-induced cable force sums (VICFS) of cable pairs (defined as two symmetric cables upstream and downstream) is proposed. First, the theoretical relationship between the vehicle load and VICFS was derived through mechanical analysis. Second, a new anomaly-sensitive warning index was established based on the above derivation, and the anomaly diagnosis for stay cables was achieved by combining it with the X-bar control chart. Then, according to finite element simulation, the variations in VICFS in different cases were analyzed to verify the rationality of the theoretical derivation and the established warning index. Finally, an engineering application to an in-service cable-stayed bridge was carried out to validate the feasibility and effectiveness of the anomaly diagnosis method. The results show that the proposed method can accurately detect and locate damaged cables, which can be successfully applied to monitor the long-term performance of stay cables. [ABSTRACT FROM AUTHOR]

The phase mixing and equilibrium process plays a crucial role in the energy cycle and fuel process of supercritical fluids. This study focuses on the dynamic phase mixing during equilibrium process. The transient high-precision measurement of the density field during the phase mixing and equilibrium process is realized by the phase-shifting interferometer based on the pixelated-array masked method. The slow density equilibrium between four typical phase transition routes is captured and quantified with the visualization images and local parameters. The interface spreading rate during the equilibrium between liquid and supercritical is at a rather high level as 0.82 mm/s on average. This phenomenon is controlled by mixing and diffusion, which are faster process than evaporation. Nevertheless, equilibrium can be retarded even in a supercritical environment during the phase mixing between liquid-like and gas-like crossing the pseudo-critical line (average value of interface spreading rate as 0.45 mm/s), where there is a significant density gradient that generates a "solid wall" (buffer layer) effect. • Transient high-precision measurement of the density field phase mixing and equilibrium process realized. • Density equilibrium between four typical routes is captured and analyzed quantatively with local parameters. • The interface spreading rate during the equilibrium between liquid and supercritical is at a rather high level. • Equilibrium can be retarded in supercritical environment between liquid-like and gas-like crossing the pseudo-critical line. [ABSTRACT FROM AUTHOR]

X-ray absorption spectroscopy at Mn K - and L -edges, and at O K -edge, combined with the x-ray diffraction and magnetization measurements are performed to study the electron structure of La 0.7 Ca 0.3 Mn 1-x Sc x O 3 (x = 0.0; 0.03, and 0.05) perovskites. Substitution of manganese by scandium decreases Curie temperature, T c, and increases lattice parameters because of the different electron configuration and radii of trivalent manganese and scandium ions. The T c decrease is explained by the change of level of hybridization of O 2 p and Mn 3 d states. This is manifested by the parallel shift of O K -edge, change of intensity of 2 p 3/2 and 2 p 1/2 spectrum lines and T C with x increase. Fourier transform of the EXAFS spectra shows a change of local crystal structure caused by the larger Sc3+ than the Mn3+ ions. • Electron structure of La 0.7 Ca 0.3 Mn 1-x Sc x O 3 manganites is studied. • Change of electron hybridization of Mn 3 d and O 2 p states is observed. • Change of Mn L -edge spectra intensity and T C is parallel with x. • Shift of O K -edge and T C is parallel with x. • Fourier transform of EXAFS spectra shows a change of local crystal structure. [ABSTRACT FROM AUTHOR]

Highlights • An improved ordinary state-based peridynamic (OSBPD) model for cohesive crack growth in quasi-brittle materials. • A new damage model proposed to describe cohesive effect in fracture process zone. • A re-loading approach for obtaining the whole structural response under load-controlled loading procedure. • Capable of quantitative simulation of the whole fracture process of quasi-brittle materials. • Accuracy of the modified OSBPD is validated by several representative fracture tests. Abstract Ordinary state-based peridynamics (OSBPD) is a well-established peridynamic (PD) model, but its applications are restricted in brittle fracture because the failure models proposed in OSBPD are mainly to describe brittle fracture rather than quasi-brittle fracture. This work attempts to propose a damage model to overcome this limitation for the investigation of damage and crack propagation in quasi-brittle materials. To this aim, a PD version of the cohesive zone model (CZM) is established in OSBPD for the fracture analysis of quasi-brittle materials. A degradation curve is proposed in the damage model to represent the cohesive effect in fracture process zone (FPZ), which is similar to the tension softening curve in CZM. The damage model can be uniquely determined once the tensile strength, the elastic modulus, the specific fracture energy, and tension softening constitutive law are given. Moreover, several representative examples of mode-I and mixed mode concrete fractures are simulated using OSBPD to validate the proposed damage model. The predicted load-displacement curves and crack paths in all the cases are in good agreement with the experimental results or other numerical results. In addition, a re-loading approach is proposed to obtain the descending part of load-displacement curve when the load-controlled loading procedure is adopted. [ABSTRACT FROM AUTHOR]

Highlights • A new DNB-type CHF prediction model of flow boiling in rifled tube at low qualities was established. • A new α b correlation was proposed based on a large number of CHF experimental data. • The present model was verified by the CHF look-up values and CHF experimental values. • Three classic CHF prediction models and the present CHF model were evaluated. • With the increase of vapor quality, the influence of pressure and mass flux on CHF weakened. Abstract Based on the near-wall bubble coalescence model and the structural characteristics of the rifled tube, improvements and optimization of the model for rifled tube were conducted. DNB-type CHF phenomenon in the rifled tube under subcritical and near-critical pressures was investigated by numerical calculation. A new CHF prediction model of flow boiling in rifled tube with low qualities was established and compiled by FORTRAN language. The model used the Staub model which considering the influence of the bubble contact angle to calculate the bubble detachment diameter. The surface friction coefficient of the rifled tube was calculated by the classical Kohler and Kastner formula. And a new critical void fraction of the wall bubbly layer α b correlation was proposed based on a large number of CHF experimental data. The present model was verified by the CHF look-up values and CHF experimental values. Based on the CHF experimental data of the rifled tube, three classic CHF prediction models and the present CHF model were evaluated, and it was found that the present modified CHF model has the highest prediction accuracy for the rifled tube, which is the best agreement with the experimental values, indicating that the present model is appropriate for DNB-type CHF prediction of the rifled tube. In this paper, the effects of pressure, mass flux and inlet fluid subcooled enthalpy on CHF were studied. It was found that, the effect of pressure and mass flux on CHF is obvious in the low quality region, with the increase of vapor quality, the influence of pressure and mass flux on CHF weakens. [ABSTRACT FROM AUTHOR]

Abstract The understanding of heat and mass transfer phenomena and underlying flow and thermal mechanisms in a tunnel fire is critical for smoke control and human evacuation. Critical velocity has been acknowledged as the most critical parameter to guarantee the effectiveness of smoke control using longitudinal ventilation in tunnels. However, in slopping tunnels, even under the conditions where the expected smoke flow route and the corresponding critical velocity can be achieved, another flow pattern which has an opposite smoke flow direction and higher gas temperatures is also likely to be generated. This phenomenon has not attracted enough attention. In this paper, multiple patterns of heat and mass flow in a slopping tunnel induced by the competition of buoyancy and forced ventilation were examined using laboratory experiments, Computational Fluid Dynamics simulations and theoretical analysis. Both dynamic and steady state analyses were performed to explain the transient evolution behaviors and final steady solutions for these flow patterns. The constraints and the prerequisite conditions for the existence of multiple flow patterns or only a certain pattern were expressed in terms of three main influencing parameters including fire heat release rate, pressure rise induced by mechanical ventilation system and the fire source location. For the regime where both fan-dominated and buoyancy-dominated patterns can occur, the initial flow state and the flow evolution process determines the steady state solutions, indicating the activation time of the mechanical ventilation plays an important role in the final flow pattern. This study has particular relevance to understanding the complex heat and mass flow behaviors in a sloping tunnel fire and it provides new implications for smoke control. [ABSTRACT FROM AUTHOR]

Abstract For next generation Li-ion batteries, advanced electrode materials with high energy densities are mightily important issue. Since the partial oxidation of Sn with Li 2 O to form SnO x was demonstrated upon delithiation in SnO 2 anode, the additional conversion reaction has contributed that the theoretical capacity of SnO 2 can be extended from 783 to 1494 mAh g−1. Herein, with the design of additional conversion reaction, we discuss key factors for high electrochemical performances of the SnO 2 anodes through comparative analysis between nano-structured mesoporous SnO 2 and conventional bulk SnO 2 , based on synchrotron radiation-based techniques, quantitative analysis of extended X-ray absorption fine structure spectra, and bond strength calculation. In this way, we demonstrate that the mesoporous SnO 2 has a nano-engineered structure with the weakened Sn-O bond strength for inducing the enhanced reversible conversion reaction as well as the facilitated electrochemical reaction, and a void structure for relieving the severe volume changes during lithiation/delithiation. Consequently, excellent electrochemical performance through the additional reversible conversion reaction is obtained in the mesoporous SnO 2. Insight from this research enables important advance in the development of metal oxide-based anode materials by making irreversible reaction reversible, providing a realizable strategy for the design and creation of high-energy storage devices. Graphical abstract Image 1 Highlights • Comparison of electrochemical reactions between mesoporous and bulk SnO 2. • Validating the key factors for high electrochemical performances of the SnO 2 anode. • Nano-engineering and weaker Sn-O bond strength can enable the additional reaction. • A stable void structure for alleviating the large volume variations is necessary. [ABSTRACT FROM AUTHOR]

Abstract Environmental issues and cleaner production are getting increasing attentions currently, making the clean production and sustainable consumption with low emissions significant. Traditional energy vehicles are increasingly unsuitable for the development of current society. It's a trend in the current vehicle market to accelerate the substitution of new energy vehicles for traditional energy vehicles. This paper makes a theoretical study on the development of new energy vehicle market supported by the government. First, this paper establishes a Cournot duopoly model which includes domestic and imported new energy vehicle manufacturers. Through the analysis of this model, this paper argues that government support policies such as subsidies and tariffs can effectively expand the market share of domestic new energy vehicles with less technology. Yet this approach is unsustainable, because domestic new energy vehicles with less technology can only survive in the market by shortening the gap with imported brands. Secondly, this paper establishes a Stackelberg model with product price as the decision variable and find that when there is a technical gap, the first mover advantage in the market will no longer exist. Finally, this paper compares two kinds of subsidies for domestic new energy vehicles and shows that the two subsidies are not different from subsidizing consumers or enterprises in expanding market share, and the consumer can obtain higher social welfare level as the subsidy object. Highlights • New energy vehicles boom with obvious substitution effect on traditional ones. • Both subsidies and tariffs can expand the production of domestic new-energy cars. • First move of domestic brands into the market can narrow the price difference. • First mover advantage no longer exists in the Stackelberg game. • Consumer subsidy is superior to enterprise subsidy in new energy auto industry. [ABSTRACT FROM AUTHOR]

Abstract Searching conductive host materials to suppress the shuttle effect is a long-term goal in the development of lithium-sulfur (Li-S) batteries. In this work, first principles calculations were carried out to systematically investigate O-functionalized Ti 2 N (Ti 2 NO 2) and F-functionalized Ti 2 N (Ti 2 NF 2) monolayers as host materials to anchor the soluble Li 2 S x species. Our results demonstrate that both Ti 2 NO 2 and Ti 2 NF 2 not only possess moderate adsorption energies towards Li 2 S x species, but also achieve a good balance between adsorption energies and intactness of Li 2 S x species, which could avoid the dissolution of Li 2 S x species into electrolyte solvents and improve the utilization of active materials. In addition, after adsorption of S 8 and Li 2 S x species, the metallic character of Ti 2 NO 2 and Ti 2 NF 2 is still preserved, which benefits the redox reaction of Li 2 S x species. Given these exceptional properties, it is expected that Ti 2 NO 2 and Ti 2 NF 2 could be promising host materials for Li-S batteries with good cycling performance. [ABSTRACT FROM AUTHOR]

Abstract It is crucial to develop a high-efficiency visible-light responsive photocatalyst for settling the increasing contamination stemmed from toxic heavy metal ions in wastewater. In this study, Cr-doped SrTiO 3 (CrSTO) nanoplates were synthesized by a facile one-pot solvothermal method with ethylene glycol as both the solvent and morphology controller. The resultant CrSTO nanoplates are about 100 nm in size and 20 nm in thickness, which are composed of SrTiO 3 nanocrystals about 19 nm in diameter. Furthermore, they possess the mesopore 3.0 nm in size, endowing their much higher specific surface area than the commercial SrTiO 3 particles. The Cr element is doped into the crystal lattice of SrTiO 3 by the substitution of Cr3+ for Sr2+, which enables the absorption edge redshift to the visible light region, thus elevating the visible-light absorption capability. In addition, the CrSTO-0.9 nanoplate with 0.9% Cr element content exhibits the highest photocatalytic performance for the Cr(VI) reduction under visible light irradiation, which can reduce nearly all Cr(VI) within 3.5 h and preserve the excellent stability after six recycles. This kind of CrSTO nanoplates may serve as a potential and promising photocatalyst for efficient Cr(VI) removal in wastewater. Graphical abstract Image 1 Highlights • Cr-doped SrTiO 3 nanoplates were fabricated by a facile one-pot solvothermal method. • Doped Cr3+ ions substitutes the Sr2+ sites in the SrTiO 3 crystal structure. • Cr doping narrows SrTiO 3 bandgap, thus facilitating the visible-light absorption. • Nanoplate structure increases specific surface area and inhibits electron-hole recombination. • Cr-doped SrTiO 3 nanoplates exhibit high reduction performance of Cr(VI) in water. [ABSTRACT FROM AUTHOR]

Highlights • Specific heat ratio, buoyancy and acceleration show weak independence on HTC. • The integral of specific heat in the boundary layer is the important factor of HTE. • The buoyancy effect in the boundary layer is the important factor of HTD. • The wall temperature deviation is minimum near the pseudo critical temperature. • The non-uniform heating can effectively delay the occurrence of HTD. Abstract Heat transfer of ultra-supercritical water in vertical upward tube under uniform heating was investigated experimentally and numerically. For comparison, similar studies under non-uniform heating were also simulated. The effects of specific heat ratio, buoyancy and acceleration on the heat transfer of ultra-supercritical water were discussed according to the experimental data. Results show that these dimensionless parameters have no single relationship of independence with the heat transfer coefficient which indicates that using them directly to predict heat transfer is inaccurate. The shear stress transport k-ω model was used in the numerical simulation. Results concur with the experimental data to a high degree, which proves that the model has strong applicability in predicting heat transfer. The mechanisms of heat transfer enhancement and deterioration were analyzed through simulation results, and the integral of specific heat in the boundary layer and the buoyancy effect were confirmed to be their main factors, respectively. Furthermore, the differences between the uniform and non-uniform heating were also revealed. The wall temperature of smooth tube under non-uniform heating shows a parabola distribution, and the peak value occurs at the midpoint of the heated side. Moreover, the peak value of the wall temperature is higher under non-uniform heating than that under uniform heating; however, the heat flux is higher when heat transfer deterioration occurs. [ABSTRACT FROM AUTHOR]

Let A be a graded algebra. It is shown that the derived category of dg modules over A (viewed as a dg algebra with trivial differential) is a triangulated hull of a certain orbit category of the derived category of graded A -modules. This is applied to study derived categories of graded gentle one-cycle algebras. [ABSTRACT FROM AUTHOR]

Highlights • A new damage model in bond-based peridynamics is established for concrete. • Quantitative investigation is conducted on the whole fracture processes of concrete. • A strategy to determine the initial cracking load of TPB concrete beams is proposed. • The influence of different definitions for computing fracture energy on numerical results. • Comparisons of different damage models in the BBPD frame are carried out. Abstract A new damage model is proposed in the bond-based peridynamics (BBPD) frame to quantitatively investigate mode-I crack propagation in concrete, which is established based on the pattern of bilinear softening curve commonly used in the discrete cohesive zone model (CZM). This new damage model can be obtained completely based on material properties, that is, once experimental bilinear softening curve, the uniaxial tensile strength, the elastic modulus and fracture energy of concrete are given, this corresponding new damage model will be exclusively determined. And then, the whole fracture processes of concrete specimens with different strengths, dimensions and crack-depth ratios under quasi-static three-point-bending (TPB) are simulated using BBPD to verify this proposed new damage model. The predicted load-crack mouth opening displacement (P-CMOD) curves are in a good agreement with the experimental ones. Finally, in the BBPD frame, a strategy to determine the initial cracking load of TPB beams, the influence of different definitions for computing fracture energy and different damage models on numerical results are discussed respectively. It can be found that different from brittle materials, fracture energy is mainly consumed in the softening stage rather than the elastic stage for concrete. Besides, this new damage model based on bilinear softening curve is more appropriate to describe the damage mechanism of concrete, compared with other damage models in BBPD. [ABSTRACT FROM AUTHOR]

Abstract An improved algorithm is proposed for image haze removal based on dark channel priority to avoid the color distortion of haze removing about sky, white cloud or bright areas. The improved algorithm is mainly reflected in the following two aspects. One is the refined atmospheric transmittance of the hazy images with non-sky obtained using guided filter. The other is that the atmospheric transmittance of the hazy images with the sky, white cloud or the bright areas is estimated by a variety of classified statistics for haze-free outdoor images with non-sky or the haze-free outdoor images with sky. Compared with He algorithm, the weakness of atmospheric transmission of the hazy images with the sky, white cloud or the bright areas is remedied. Experimental results show that the improved algorithm is efficient to image haze removal. [ABSTRACT FROM AUTHOR]

[Display omitted] • Complexes 1 , 2 and 3 exhibit reversible photochromic behavior. • Complexes 1 , 2 and 3 exhibit long-lived persistent phosphorescence. • Complex 2 exhibits excitation wavelength dependent fluorescence. • Three complexes show great potential in data encryption and anticounterfeiting. • 2 was fabricated in inkless printing performance and information transmission. Long persistent luminescence materials have wide application prospects in the fields of optical communication, sensors, and anticounterfeiting. Recently, some researchers have proved the feasibility of charge transfer effect in the construction of visible light excited room temperature phosphorescence (RTP) materials. However, materials with electronic effects require elaborate design to exhibit long-lived phosphorescence. Herein, a series of coordination compounds based on viologen ligand HL⋅Cl (4-carboxybenzyl)-4,4′-bipyridinium chloride) and Zn2+ with benzoic acid derivatives (o- , m- , p- phthalic acid) were reported. They exhibit not only reversible photochromic properties, but also long-lived persistent phosphorescence. Three complexes possess different structures through different auxiliary ligands with different optical physical properties. Complex 1 exhibits dynamic phosphorescence emission at low temperatures. Interestingly, we synthesized the first viologen complex (complex 2) with excitation wavelength dependent fluorescence, and the emission color gradually changed from blue to red with the increase of excitation wavelength. In addition, the applications of three complexes in data encryption and anticounterfeiting are further demonstrated. This work not only presents coordination compounds with dynamic afterglow materials, excitation wavelength- and time-dependent emission properties, but also provides a new strategy for the charge transfer effect in visible light-excited RTP materials. [ABSTRACT FROM AUTHOR]

We present the numerical solution of the leading order QCD evolution equation for the orbital angular momentum distributions of quarks and gluons and discuss its implications for the nucleon spin sum rule. We observe that at small- x , the gluon helicity and orbital angular momentum distributions are roughly of the same magnitude but with opposite signs, indicating a significant cancellation between them. A similar cancellation occurs also in the quark sector. We explain analytically the reason for this cancellation. [ABSTRACT FROM AUTHOR]

In this study, a series of experiments are performed to investigate the mixing and stratification of buoyancy-driven flows in a narrow inclined tank. The buoyancy-driven flow is produced by continuously releasing dense brine into an inclined tank filled with fresh water. Two distinct mixing regimes are identified. In one of the regimes, fresh water enters the tank because of the negative pressure induced by the brine plume. In the other regime, the fresh water inflow is mainly caused by the stack effect. A light attenuation technique is used to measure the density stratification and distribution in the tank. The effects of the buoyant source volume flow rate, source buoyancy flux, and source location on the mixing and stratification are investigated. The results indicate that the mixing between the buoyant and ambient fluids is strengthened by the increase in the source volume flow rate and the height difference between the source location and the lower end of the tank. However, the current downstream of the source becomes more stratified as the source buoyancy flux increases. A dimensionless parameter, λ , is proposed to evaluate the overall mixing intensity in the tank. As λ increases, the flow changes from a bidirectional one to a unidirectional one. The evolution of reduced gravity along the longitudinal direction is also investigated. The results indicate that fresh water is entrained into the brine layer if the thickness of the brine layer is less than the tank height. Otherwise, the reduced gravity remains constant along the longitudinal direction of the tank. [ABSTRACT FROM AUTHOR]

In recent years, assembling 2D layered materials into three-dimensional (3D) architectures has become the research focus in catalysis fields. In this study, 3D porous g-C 3 N 4 @carbon (CN@C) microflowers composed of carbon-coated g-C 3 N 4 nanosheets were prepared by a facile bio-inspired method. At first, cyanuric acid-melamine (CAM) supermolecules were assembled into 3D microflowers with the mediation of sucrose molecules through a hydrothermal process, and then isomorphically converted into 3D CN@C microflowers upon calcination. By varying the saccharide species, it was found that the formyl groups of saccharide molecules and their self-polycondensation behavior could govern the CAM assembly and subsequent formation of microflower structure. The resultant CN@C microflowers exhibit high oxygen evolution reaction (OER) activity with a potential of 1.68 V at a current density of 10 mA cm −2 due to efficient mass and charge transfer, which is close to the reported value for the state-of-the-art metal catalyst IrO 2 /C (1.60 V, 0.1 mol L −1 KOH) and much superior to that of pure g-C 3 N 4 . [ABSTRACT FROM AUTHOR]

The dynamics of back-layering flow induced by a continuous buoyant release in a naturally ventilated inclined tunnel are investigated. The back-layering length and the density difference between the buoyant back-layering and the ambient flow are investigated using brine water experiments. The back-layering length is independent of buoyancy flux of the releasing source in such a configuration; however, the density difference between the buoyant back-layering and the ambient flow increases with a 0.52 power function of buoyancy flux. The back-layering fluid density is remarkably larger than that of downstream flow. In particular, we focus on the critical condition for preventing back-layering in such a naturally-ventilated tunnel configuration. The longitudinal flow in an inclined naturally-ventilated tunnel is assumed to be induced by the stack effect. We firstly derive a theoretical equation for predicting the critical condition for an inclined tunnel and identify that the critical condition is sensitive to buoyancy source location, but it does not exhibit any significant dependency on buoyancy flux of the source. The experimental results show that, in a wide range of values of buoyancy flux, the conclusions derived from the theoretical analysis are valid, indicating the critical velocity can be achieved in an inclined tunnel without any forced mechanical flow, and the condition for achieving the critical velocity is mainly dependent of buoyant source location. [ABSTRACT FROM AUTHOR]