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In this paper, we consider a 2D stochastic quasi-geostrophic equation driven by jump noise in a smooth bounded domain. We prove the local existence and uniqueness of mild  L p (D) -solutions for the dissipative quasi-geostrophic equation with a full range of subcritical powers  α ∈ (1 2 , 1 ]  by using the semigroup theory and fixed point theorem. Our approach, based on the Yosida approximation argument and Itô formula for the Banach space valued processes, allows for establishing some uniform bounds for the mild solutions and we prove the global existence of mild solutions in  L ∞ (0 , T ; L p (D))  space for all  p > 2 2 α − 1 , which is consistent with the deterministic case. [ABSTRACT FROM AUTHOR]

Highly ordered nanotubes titanium dioxide (NTs-TiO2) array was fabricated and used as the support of Pt nanoparticles for the selective aqueous phase of glycerol (GLY) electrooxidation. The structure and morphology of the NTs-TiO2/Pt were characterized by X-ray diffraction, scanning electron microscope, transmission electron microscope, etc. The electrooxidation GLY properties of NTs-TiO2/Pt were investigated by cyclic voltammetry, linear sweep voltammetry, and accelerated service life test. The results show that, compared with bulk Pt and nano-TiO2/Pt, the NTs-TiO2/Pt have the highest service life and electrooxidation activity and selection for GLY. At the reaction condition of 1.2 V potential, the NTs-TiO2/Pt catalyst afforded 67.1% selectivity for the glyceric acid. [ABSTRACT FROM AUTHOR]

Aluminum alloy parts are widely used in aerospace and other fields due to their light weight and good corrosion resistance. However, during the forming process, uneven deformation can lead to high residual stresses and low forming accuracy in the parts, ultimately seriously affecting the subsequent service performance. In this study, the influence of the cryogenic–vibration compound field on the residual stresses, microstructural evolution, and forming accuracy were investigated based on the deep drawing experiment of aluminum alloy cylindrical parts. The results indicate that when compared to the absence of cryogenic and vibration, the compound field can reduce residual stresses in the parts by 22%, which is attributed to lower dislocation density and more uniform distribution of low-angle grain boundaries. The cryogenic environment can weaken the degree of dislocation entanglement in low-angle grain boundaries, meanwhile, the dislocations are easily dissociated and released under the vibration. The maximum sidewall thickness difference, the sidewall height difference, and the surface roughness decrease by 68, 69, and 52%, respectively, which is due to the uniform distribution of microstructure and the reduction of frictional resistance caused by the boiling liquid nitrogen. This study provides a new method for the forming of high-quality aluminum alloy parts. [ABSTRACT FROM AUTHOR]

Highlights • In this paper, a camera calibration method is proposed to acquire the checkerboard image by adding polarizer before the camera lens. • By introducing the Stokes variable feedback to obtain the optimal polarization angle of the checkerboard image to remove or suppress the high optical region influence in the image acquisition, the optimal polarization angle chessboard image can be used to improve the coordinate precision of corner point. • The accuracy of sub-pixel coordinate extraction makes the result of camera calibration more accurate. • Compared with the previous methods to improve the accuracy of corner extraction considers the idea of improving angle extraction accuracy from the algorithm level. • This paper focuses on the image processing of corner image acquisition, and has the relative innovation in the way and method. Abstract The accurate estimation of camera internal and external parameters is one of the keys to high-precision camera calibration. At present, the mainstream Zhang's calibration method requires the use of a checkerboard to achieve high-precision calibration result. Therefore, the precise extraction of the pixel coordinates at the corner points on the checkerboard is one of the key technologies. The traditional methods are to improve the corner extraction algorithm, but ignore the imaging process of the calibration images. It is difficult to detect and eliminate the high-light regions in the process of calibrating image, and the existence of high-light regions will cause low accuracy of camera calibration. Therefore, a camera calibration method based on optimal polarization information is proposed in this paper. The method first uses a Stokes variable linear feedback through a CCD camera equipped with a polarizer to obtain a checkerboard calibration image at an optimal polarization angle in different spatial positions. Then use the sub-pixel level detection algorithm and Gaussian fitting method to locate the corner points in the image and to solve the sub-pixel coordinates of the corner points precisely. At last, the two-dimensional pixel coordinates of the corner points in each checkerboard image are extracted to perform camera calibration. The experimental results show that the coordinates of corner points of calibration plate image based on the optimal polarization angle have about 1 pixel difference compared with the coordinates of the calibration plate corner points under natural illumination, and the slopes between the parallel lines of the fitted are closer, meet the high precision calibration requirement of camera. [ABSTRACT FROM AUTHOR]

The pyrolysis characteristics and kinetics of lignocellulosic biomass (cotton stalk) and seaweed (Gracilaria lemaneiformis) were studied comparatively. Results of the thermal degradation processes showed that the pyrolysis occurence of G. lemaneiformis is easier than that of cotton stalk. However, G. lemaneiformis released less volatile components and produced more solid residues. As the heating rate increased, the maximum mass loss rates for cotton stalk were decreased, while those for G. lemaneiformis were increased. Results of the kinetic analysis by Popescu method indicated that the pyrolysis mechanism of cotton stalk is three-dimensional diffusion, which can be described by Zhuralev, Lesokin, and Tempelmen (Z-L-T) equation (G(α)={[1/(1-α)]1/3-1}2), whereas that of G. lemaneiformis is random nucleation and nuclei growth, which can be described by Avrami-Erofeev equation (G(α)=[-ln(1-α)]1/4). The average activation energy values (192.17 and 146.11 kJ mol−1, respectively) of cotton stalk and G. lemaneiformis obtained by Popescu method are similar with those (189.88 and 153.79 kJ mol−1, respectively) calculated by Flynn-Wall-Ozawa (FWO) method. Moreover, the average activation energy of G. lemaneiformis is lower than that of cotton stalk. [ABSTRACT FROM AUTHOR]

Obtaining square cups with the radius at the bottom corner lower than the thickness of original plate via a single-step hot forming process is a challenge. In this paper, a processing way was proposed by combining local-thickened plate and friction control, to manufacture square cups with small corner radii. Through finite element (FE) simulations, the metal flow during hot forming of square cups was optimized by varying the shape of the local thickened section and adjusting the friction conditions at the interfaces between blank and tools. It was found that the filling ratio of the bottom corner can be significantly improved by increasing the friction coefficient at the interfaces between the blank and the upper punch, and that between the blank and the central zone of counter punch. The established flow dividing surface (FDS) model is capable for describing the variation of metal flow with the friction coefficients. Base on the simulation results, hot forming experiments were also carried out, and square cups with small radii of 2 mm at the bottom corners were successfully manufactured. [ABSTRACT FROM AUTHOR]

The melting behaviors of copper nanorod are studied by employing molecular dynamics simulations with the embedded atom method potential during a temperature elevation process from 200 to 1600 K. The melting point decreases with the diameter of the nanorod decreasing. Upon heating, copper nanorod shows thermal instability at two critical temperatures and undergoes two structural transitions: shape transition changing to a shorter and wider shape, and melting transition changing to a liquid sphere. The shape change of the nanorod is closely related to the atoms rearrangement, which results from releasing the stress in the inner layers of the nanorod motivated by heating. Besides, the nanorod with void defects goes through the same structural transition. This work will help deepen understanding of the thermodynamic evolution in copper nanorods. [ABSTRACT FROM AUTHOR]

Accurately estimating the spatial distribution of forest aboveground biomass (AGB) is important because of its carbon budget forms part of the global carbon cycle. This paper presented three methods for obtaining forest AGB based on a forest growth model, a Multiple-Forward-Mode (MFM) method and a stochastic gradient boosting (SGB) model. A Li-Strahler geometric-optical canopy reflectance model (GOMS) with the ZELIG forest growth model was run using HJ1B imagery to derive forest AGB. GOMS-ZELIG simulated data were used to train the SGB model and AGB estimation. The GOMS-ZELIG AGB estimation was evaluated for 24 field-measured data and compared against the GOMS-SGB model and GOMS-MFM biomass predictions from multispectral HJ1B data. The results show that the estimation accuracy of the GOMS-MFM model is slightly higher than that of the GOMS-SGB model. The GOMS-ZELIG and GOMS-MFM models are considerably more accurate at estimating forest AGB in arid and semiarid regions. [ABSTRACT FROM PUBLISHER]

This study investigated postmortem changes of yellowfin tuna (Thunnus albacares) and water migration upon storage at 0°C and 4°C as determined by low-field nuclear magnetic resonance (LF-NMR1H). It clearly showed that with increasing storage time, sensory scores and physical evaluations (hardness, chewiness), proton density of the water, and moisture content decreased, while total volatile basic nitrogen (TVB-N),Kvalue, aerobic plate counts (APCs), and psychrotrophic bacterial counts increased. The results of LF-NMR showed thatT21(trapped water) had extremely significant correlations with sensory evaluation, texture profile analysis, TVB-N,Kvalue, APC, and psychrotrophic bacteria (p < 0.01) and established multiple linear regression. It was concluded that the LF-NMR was an important technique to evaluate storage time and temperature of yellowfin tuna’s quality in terms of water migration during low-temperature storage. [ABSTRACT FROM AUTHOR]

The influence of sub- T g pre-annealing on the kinetics of glass transition and crystallization of a lightweight Ti 41 Zr 25 Be 28 Fe 6 bulk metallic glass (BMG) has been investigated by isochronal and isothermal differential scanning calorimetry tests. It was found that sub- T g annealing obviously enlarges the supercooled liquid region of Ti 41 Zr 25 Be 28 Fe 6 BMG, indicating an enhanced thermal stability. The activation energies for glass transition and crystallization of the as-cast and pre-annealed samples have been calculated and compared. The pre-annealed samples possess smaller values of fragility parameter and longer incubation times upon isothermal heating compared with the as-cast sample, indicating a retarded crystallization process. The isothermal crystallization kinetics of the samples with different annealed states has been investigated in terms of the Johnson-Mehl-Avrami equation and local Avrami exponent. The current study reveals a clear sub- T g annealing effect on the kinetics of glass transition and crystallization of Ti 41 Zr 25 Be 28 Fe 6 glassy alloy and the possible mechanisms have also been proposed. [ABSTRACT FROM AUTHOR]

A local-heating rotary-forming process, which was similar to a rotary beading forming process, was developed to produce a rim-thickened disc-like part. A motion controlling model and a power controlling model based on a Gaussian-distributed flame heat source were established to provide references for deciding heat input. Via FE simulation, deformation rules including various field distributions were explored. It was found that local heating can result in large temperature gradients in the blank and introduce different flow stresses in different local sections. Compared with cold rotary forming processes designed for rim thickening, smaller but more uniform stress fields can be achieved by this new forming process. In addition, the required forming force is decreased, which is beneficial to the stable thickening of large-sized blanks. Furthermore, the influencing law of heating temperature during preheating and thickening on the forming quality was investigated. It was implied that the peak preheating temperature should be lower than 700 °C and the ideal heating temperature in the deformation forefront is around 950 °C. Experiments were carried out for verification, with a maximum rim thickening ratio of 2.6 achieved, which is much higher than those in cold rotary forming processes. [ABSTRACT FROM AUTHOR]

The room temperature creep behavior of a newly developed Ti 16.7 Zr 16.7 Hf 16.7 Cu 16.7 Ni 16.7 Be 16.7 high entropy bulk metallic glass was investigated by nanoindentation measurements with various loading rates in comparison with that of a typical conventional Vitreloy 1 bulk metallic glass. A generalized Kelvin model was adopted to describe the creep curves. It was found that for both the two studied alloys, the creep displacement and strain rate sensitivity increases with increasing loading rate, indicating a positive loading rate effect. Vitreloy 1 BMG exhibits a more obvious loading rate effect compared with Ti 16.7 Zr 16.7 Hf 16.7 Cu 16.7 Ni 16.7 Be 16.7 HE-BMG. The creep compliance and retardation spectra were also derived to study the creep mechanism. Compared with other developed high entropy alloys and bulk metallic glasses (e.g. Vitreloy 1 alloy), the studied HE-BMG possesses relatively small strain rate sensitivity values, indicating a good creep resistance. Based on the experimental results, the mechanisms of the unique creep resistance of Ti 16.7 Zr 16.7 Hf 16.7 Cu 16.7 Ni 16.7 Be 16.7 high entropy bulk metallic glass have also been explained. [ABSTRACT FROM AUTHOR]

As a process controlled by ionic diffusion, the oxidation process of metals and alloys is sensitive to the stress states of diffusion medium. In this study, by applying static tensile/compressive load on samples during oxidation, the influence of stress states on the oxidation behavior of Zr 55 Cu 30 Al 10 Ni 5 BMG in its supercooled liquid region was investigated. It was implied that compressive stress inhibits the oxidation while tensile stress has the opposite effect. This influence effect is obvious at relatively low temperatures but becomes less significant with the temperature rising. The influencing mechanism of stress state on BMG oxidation is discussed from the aspect of ionic diffusion, that is, stress state changes the charged vacancy concentration at the scale/substrate interface and thereby affects the oxidation rate. [ABSTRACT FROM AUTHOR]

The deformation behavior of a material is closely related to its preferred orientations. Usually, material contains more than one preferred orientation, and the combination of different preferred orientations makes the deformation behavior more complicated. In this study, the effects of orientation combination on the deformation substructure characteristics of an extruded Al-Cu-Li alloy were investigated. Isothermal compression tests of Al-Cu-Li samples with different orientation combinations were conducted to study the flow stress behavior. The microstructure of the deformed samples was examined and analyzed by electron backscatter diffraction. A novel deformation restriction factor γ ′ has been proposed to compare the deformation restriction of different orientation combinations. It was found that compared with the sample which contains 〈001〉&〈101〉 orientation combination, the sample containing 〈001〉&〈111〉 orientation combination possesses higher subgrain misorientation and finer grain size because of the larger deformation restriction between 〈001〉&〈101〉 orientated grains. The present work shows that it is feasible to control the continuous dynamic recrystallization microstructure of the Al-Cu-Li alloy by adjusting the original orientation combination. [ABSTRACT FROM AUTHOR]

One of the primary hurdles in microdevice fabrication lies in ascertaining the most impactful tactics for adapting metal surfaces. Through a one-pot tackle and distinct mechanochemical reactions evoked by 15 min aqueous wet sand-milling (SM-15), we successfully grafted Mo-based metal–organic frameworks (Mo-MOFs) onto graphene oxides (GOs). Following this, a convenient and readily scalable methodology of electrophoretic deposition was implemented to create controllable thickness of SM-15 GOs@Mo-MOFs lubricating films, achieving considerable enhancements of 143% and 91% in hardness and Young's modulus, respectively, when compared to those of SM-15 Mo-MOFs. The successful synthesis of SM-15 GOs@Mo-MOFs was corroborated using strategies such as x-ray diffraction, Fourier transform infrared spectroscopy, and field emission scanning electron microscopy. Analyses using the micro-tribotester indicated that the new film exhibited a lowest friction coefficient of roughly 0.5 when imposed with a load of 5 N and sliding speed of 8 mm/s. In addition, the optical profiler nano-indentation in situ scanning probe microscope revealed that SM-15 GOs@Mo-MOFs films had smaller and shallower scratches and grooves compared to SM-15 Mo-MOFs ones. The calculated results of key descriptors (EHOMO, ELUMO, ΔE, etc.) in density functional theory quantitatively disclosed the interaction mechanisms between GOs@Mo-MOFs molecules and microdevices. We first scrutinized the innate properties of molecule adsorption energy and frictional mechanical behaviors using synergetic cross-scale simulations, such as Monte Carlo and finite element methods. The expectation was that this process would motivate a valuable technique for shielding in the thriving micromanufacturing. [ABSTRACT FROM AUTHOR]

Mesoporous composite TiO2-ZrO2(TZ) having enhanced surface area was synthesized by sol-gel process. The structure of the prepared samples was characterized by X-ray diffraction, transmission electron microscope, energy dispersive spectrometer, scanning electron microscope, N2sorption techniques, etc. Electrocatalytic reduction of 2-pyridinaldehyde in 1-ethyl-3-methylimidazolium tetrafluoroborate (EMI-BF4) on the mesoporous TZ composite film electrode was investigated by cyclic voltammetry (CV). A comparison of the CV recorded in the absence and presence of 2-pyridinaldehyde confirmed the catalytic reduction of 2-pyridinaldehyde produced 2-piperidinemethanol by Ti(III)/Ti(IV) redox couple on the surface of mesoporous TZ composite film. The mechanism of this electrode reaction is called catalytic (EC′) mechanism. [ABSTRACT FROM AUTHOR]

Disk-like parts with both thin web plates and thick rims are widely applied in automotive and aviation industries. These parts are usually made via welding and machining, which often lead to low material utilization, high energy consumption and low product performance. Therefore, a new sheet blank rotary forging process for thickening the rims of disc-like sheet blanks with uniform thicknesses was proposed in this paper. Based on FEA and experiments, both the effects of main defects and process parameters on forming were investigated. Besides, by considering the flow line distribution in formed parts, the material deformation feature in the forming process was analyzed. The results showed that the deformation process can be divided into four stages, and there are mainly four kinds of defects occurring during forming. Materials in the outer side of rim flows not only in the radial direction but also in the tangential direction. [ABSTRACT FROM AUTHOR]

In this study, a single-step hot stamping-forging process using a counter punch was proposed to produce pan-shaped shell parts with nonuniform thickness distributions, which are often used in satellites. Through FE simulations, the effects of die temperature, counter punch initial interposition length and counter force on the part thickness were examined. It was found that the material flow is divided at a flow dividing surface (FDS) which moves in the wall during forming. The maximum bottom thickness and nonuniformity were found to be closely related to the counter force and initial interposition length. Base on the simulation results, experiments were carried out using sheet blanks with initial thicknesses of 4 mm. After stamping-forging deformation, the part bottom was successfully thickened to 4.3 mm while the wall was thinned to 2.5–2.7 mm. [ABSTRACT FROM AUTHOR]

A new rotary forming process for rim thickening was proposed in this paper, which can be applied on sheet metals to produce parts with thin web plates and thick rims integrally. Via FE simulation, an orthogonal test was conducted to investigate the effects of forming parameters on γ max , which is the ratio of maximum blank size to thickness and indexes the stability of sheet metals while during forming. It is found that the incline angle of the upper roller groove surface, and the friction condition between the sheet metal and roller groove are the dominant factors affecting the process, while the influence of the feeding velocity and the groove arc radius are relatively slight. It is also proved that interactions exist among these factors. Furthermore, an optimized parameters group is obtained, and a process window plot showing the limits of the forming process is achieved. The facticity of FE simulation is verified by technological experiments. [ABSTRACT FROM AUTHOR]

The shock forming process of Cu 50 Zr 50 metallic glasses is investigated via the classical molecular dynamics method. The velocity and density profiles are presented to describe the shock wave propagation, and the displacement vector is used to trace the atomic flow. The shock forming process is accompanied by the evolution of the internal short-range order of the metallic glasses. Beside, the influence of piston velocity and mould size on the shock forming process is explored. It is found that the suitable shock pressure is in the range of 18–30 GPa, with which the filling rate could be higher than 85%. A larger fillet radius or a smaller mould opening size is advantageous to alleviate the residual stress concentration. The sample obtained by shock forming exhibits better plasticity compared with the as-cast sample, which could be explained by the change in the number of the dominated Voronoi polyhedra. [ABSTRACT FROM AUTHOR]

Grassland is one of the most widely distributed terrestrial ecosystems on Earth. It is critical to accurately estimate grassland biomass of the desert steppe, and to understand its dynamics changes in order to study the regional carbon cycle and the sustainable use of grassland resource. The integration of multisensory data provides the opportunity to explore the benefits of grassland biomass effective estimation via multiple data sources. Based on the field survey data, quadrature-polarization (qual-pol) RADARSAT-2 Synthetic Aperture Radar (SAR) C-band data was utilized to develop a biomass regression model and estimate the aboveground biomass (AGB) of the Caragana microphylla shrubbery in the desert steppe region in the northwest of China. The research area was located at Yangzhaizi Village in Ningxia Autonomous region. Grassland inventory was carried out in 45 randomly distributed plots (30 m × 30 m), and the data was used for either model development or validation. An allometric regression model was established to estimate its biomass for every Caragana microphylla shrub with CH (crown width multiple plant height) variable. The local allometric regression equation was applied to calculate AGB per plot. Furthermore, the correlation between the aboveground biomass of Caragana microphylla shrubbery and the radar backscatter coefficient was analyzed. The AGB regression model was developed by integrating field measurements of 25 sample plots with RADARSAT-2 backscatter remotely sensed data. The multiple stepwise regressions algorithm was applied to develop the AGB model and estimate the grassland above-ground biomass from RADARSAT-2 backscatter data. The developed model was validated by using 20 independent sample plots. Simultaneously, RADARSAT-2 images were fused with the optical HJ1B data by using a discrete wavelet transform for the land cover classification. The image classification based on the objects was performed by using the empirical-statistical machine learning techniques, such as a classification and regression trees (CART) algorithm. The overall accuracy and Kappa value of the proposed method was 90.2% and 0.88, respectively. It indicated that the proposed method performed well for the land use and land cover (LULC) classification. An AGB biomass distribution map was produced by RADARSAT-2 backscatter data in combination with the land cover classification image and AGB regression model. As a comparison, the AGB from RADARSAT-2 estimates were compared with the results from the HJ1B normalized difference vegetation index (NDVI) model. The result showed that there was a good quantitative relationship between the AGB from the microphylla shrubbery and the RADARSAT-2 radar backscatter coefficient. A good fit was found between AGB estimated by RADARSAT-2 and ground-measured biomass with a R² (coefficient of determination) and Root Mean-Square Error (RMSE) of 0.71 and 14.2 kg/hm² respectively. Its estimated accuracy was higher than that of the HJ1B NDVI model (R²=0.27, RMSE=20.58 kg/hm²). Consequently, the fusion of optical and radar data for the land cover classification could effectively improve the accuracy of the object recognition for the land cover classification and the estimation accuracy of AGB estimation. Radar remote sensing data could be used for quantitative studies on grassland structural parameters. Moreover, it demonstrated a high potential for monitoring indicators of grassland ecosystem by combining the optical with polarimetric SAR remote sensing imanges. [ABSTRACT FROM AUTHOR]

• Oxidation occurs with the formation of oxide clusters. • Local atomic volumes increase around the oxide clusters. • Oxides lead to dynamic slowdown and stabilizes the glass-forming liquid. Oxygen has long been a concern in metallic glass-forming liquids since a minor addition can have a significant influence on liquid properties and glass formation, especially by inducing crystallization. However, how exactly oxygen affects the atomic structure and liquid properties on atomic level remains unclear to date. Here, by using extensive reactive molecular dynamics simulations, we conduct a comparative study of the atomic structures and diffusion behavior in both Al-Ni and its oxygen-containing liquids. We find that the oxidation occurs with the formation of extremely stable oxide clusters with the bonding preference between Ni and O atoms. The presence of the oxide clusters results in an increase in free volumes around them. It is the covalent bonding as well as the local excess volumes around the oxides that lead to changes in diffusion coefficients. The diffusion coefficients follow the Arrhenius relation at high temperatures, but a dynamical crossover happens above the glass transition temperature. We show that the diffusivity still correlates well with the free volume as predicted by Cohen and Turnbull although the effect of oxide clusters is not considered. This fundamental discrepancy may challenge our current understanding of liquid properties. [ABSTRACT FROM AUTHOR]

Abstract: In this paper, mechanical properties of a deformed Al–Si eutectic alloy processed by isothermal extrusion at temperature from 573K to 773K with reduction ratio from 25% to 85% were investigated at ambient temperature. The results showed that a banded structure composed of matrix region and accumulation region of second phase particles was formed and a few cracks were generated in particles and evolved to voids among particles. The tensile strength of test specimens ranged from 250MPa to 400MPa and was directly related with temperature from 623K to 773K. The elongation of test specimens ranged from 2.8% to 13.1%, and had a peak value at 673K under each section reduction ratio. A reduction in elongation occurred at section reduction ratio larger than 75% because of particle bands splitting aluminum matrix severely. The effect of temperature on mechanical properties was more significant than that of section reduction ratio. Excellent balance between strength and ductility can be obtained by extrusion at temperature 623–723K and section reduction ratio 40–70%. [Copyright &y& Elsevier]

• In this work, we report the finding of the long-sought after atomic mechanisms of oxygen effects on the atomic structure and brittleness of metallic glasses. • Oxygen is generally considered to have adverse effects on metallic glass formation and mechanical properties by embrittlement of the materials, but our work shows that in certain cases it could lead to improvement in ductility. • In this paper, we report the first atomistic simulation in investigating underlying microscopic mechanisms and atomic structure changes for the beneficial ductility improvement from oxygen addition as reported from experiments. • This finding may lead to a paradigm shift in development of the metallic (glassy) materials. • Our theoretical prediction is independently confirmed by an experimental group where the oxygen effects were examined without our knowledge in real metallic glasses. It is not common that the atomistic simulation can achieve this level of predictability. Metallic glass is a brittle solid macroscopically but has tremendous ductility in nano and mesoscopic scales. Oxygen is generally considered to be the major culprit in causing the brittleness by inducing crystallization. Since oxygen is omnipresent in the making and applications of metallic glasses, how to avoid, and even take advantage of oxygen, becomes materials scientists' wild dream. Here we demonstrate using atomistic simulation that the brittle solid can be turned ductile in a model Al-based metallic glass with oxygen addition. There are two major underlying mechanisms found here, one is to keep the oxides in small size and the other is to preserve the free volumes in the surroundings of the oxide clusters. The relatively loosely packed neighboring regions of the nanosized oxide clusters make the glass softer and thereby improves deformability and thus ductility. The finding challenges experimentalists to explore and discover new class of glasses that are not only oxygen tolerant but beneficial in mechanical properties. [ABSTRACT FROM AUTHOR]

Seafood is widely distributed and globally-favored "blue food" with increasing growth of market requirement. Nowadays, rising concerns about inherent off-flavors and food quality limit consumer. However, seafood with high protein content is highly susceptible to the production of hydrogen sulfide (H 2 S) by microorganisms and enzymes, which affects the flavor and quality of seafood. Therefore, controlling the formation of H 2 S in seafood is crucial for the development of seafood industry. This paper focuses on the formation pathways, functional properties, and hazards of H 2 S in seafood. It also covers the detection and control methods for H 2 S, addressing current challenges in technology related to its detection and control. The significance of real-time H 2 S detection and prevention of its formation in seafood is discussed. The pathways of H 2 S formation in seafood mainly include degradation of sulfur-containing amino acids by endogenous enzymes and the reduction of sulfate by microorganisms. The production of H 2 S plays a crucial role in the antioxidant and drug resistance of microorganisms. The detection of H 2 S mainly includes spectrophotometry, chromatography, rapid sensing methods, and the production of H 2 S is usually controlled by methods such as modified atmosphere packaging, lysozyme, and essential oils. In the future, it should be strengthened in the application of hurdle technology to promote the development and application of H 2 S detection and control technology in seafood, which will greatly guarantee the shelf-life extension and safe consumption of seafood. • Hydrogen sulfide is an important indicator of seafood spoilage. • Hydrogen sulfide is produced by endogenous enzymeand microbial reduction of sulfates. • Monitoring methods like spectrophotometry, chromatography, and rapid sensing methods. • Control technology like physical methods, biological methods, chemical methods. • Controlling the production of hydrogen sulfide is crucial for maintaining the quality of seafood. [ABSTRACT FROM AUTHOR]

• This paper presents a simple method for calibrating structured light systems. • Compared with the existing structured light system calibration methods on the market, there is no need for complicated system structure and cumbersome solving process. • To a certain extent, it guarantees high calibration accuracy and reduces the absolute demand for the calibration environment. • The method proposed in this paper is more suitable for the industrial production application with poor calibration environment. In a complex industrial environment, it is not appropriate to use the traditional Zhang's calibration method to shoot multiple checkerboard images in different positions, and due to the contour characteristics of the cylindrical target, camera calibration and line-structured calibration can be simultaneously performed. Therefore, a complete calibration method for a line-structured light system based on a single cylindrical target is proposed. The calibration process is as follows: Placing the cylindrical target at least once and illuminate it with the light strip of the laser projector. The vision sensor captures the target image and then extracts the laser stripes and contour images of the cylindrical target. According to the contour characteristics of the cylindrical target and the definition of the collinear vector, the extracted contour image is used to solve the internal parameters of the camera. Because the line-structured light plane and cylindrical target intersection line in the axial of cylindrical is a standard circle, the equation of the light plane is established on the camera coordinate system. The effectiveness of the method is verified by simulation and physical experiments. The experimental results show that the RMS errors of the 30 distance is 0.07 mm. The proposed method does not need to rely on the constraints of multiple images and is simple to operate, meeting the requirements of industrial 3D measurement technology. [ABSTRACT FROM AUTHOR]

The WC/W2C eutectic reinforecement was applied to suppress the formation of interfacial reaction layer TiC in titanium matrix composites due to the lower interfacial reactivity between W2C and Ti. W solid solution interface was successfully produced at the WC/Ti interface, while the most readily formed compact reaction layer TiC was completely delimitated. Such W solid solution interface is more effective to transfer stress from the matrix to the particles than that of the TiC layer. Decohesion of the W interface was never occurred. [ABSTRACT FROM AUTHOR]

Hydrogen isotope permeation in structural steels can cause severe issues, including steel brittleness, fuel loss, and radioactive pollution in fusion reactors. To tackle this issue, we report a simple synthesis of α‐Al2O3/AlPO4 composite coating by the thermochemical reaction method to serve as an effective barrier hampering hydrogen isotope permeation. This coating was formed at 500°C and composed of α‐Al2O3 and AlPO4 phases. A relatively uniform and compact structure with thickness of ∼35 μm made its corrosion resistance reaching above 3000 times that of the 321 steel substrate. With just one‐side coated, the α‐Al2O3/AlPO4 coating achieved a considerable deuterium permeation reduction factor of 1935 at 450°C, three orders of magnitude higher than 321 steels. What's more, after the deuterium permeation test, no pores or cracks were generated. The excellent bonding between the coating and the substrate was resulted from the formation of CrxPy at their interface induced by Cr diffusion from the substrate. The results obtained from the current study shed new light on seeking reliable and viable ceramic coatings to tackle hydrogen permeation issues. [ABSTRACT FROM AUTHOR]

The isothermal compression (1050 °C) of a 304-type austenite stainless has been employed to understand the roles of strain rates (0.001, 0.01, 0.1, 1, and 10 s−1) and twinning in flow behaviors and microstructure evolution. Using electron backscatter diffraction (EBSD) and transmission electron microscopy (TEM) analysis, it was determined that the alloy underwent discontinuous dynamic recrystallization (DDRX) and continuous dynamic recrystallization (CDRX) in low and high strain rate regimes, respectively. In the low strain rate regime, twinning contributed to the separation of the bulged region for dynamic recrystallization (DRX) nucleation, and Σ 3 twin boundaries mainly formed by 'growth accident' during the subsequent growth of nuclei. In the high strain rate regime, twinning did not require boundaries migration, and altered the orientation of boundary fronts, thus promoting the extension of the DRX area. Grain size exponents in low and high strain rate regimes were calculated to be −0.68 and −2.9, respectively. It was also confirmed that different DRX mechanisms result in distinct evolution of grain size, and the dividing point was determined to be the strain rate of 0.1 s−1. • Effects of strain rate on flow behaviors and microstructure evolution during hot deformation were analyzed using TEM and EBSD. • DDRX and CDRX mechanisms for different strain rate regimes were proposed. • Twinning mechanisms for two types of DRX were clarified to be different. • Grain size exponents were calculated to be −0.68 and −2.9 in low and high strain rate regimes, respectively. [ABSTRACT FROM AUTHOR]

Making composites with crystalline inclusions can improve plasticity in brittle metallic glasses. In this study, we show a new metallic glass matrix composite designed with a gradient network architecture made of amorphous matrix regions and gradient crystalline network regions. Using molecular dynamics simulations, we validated theoretically the hypothesized concept of this new composite. Our results show that the unique microstructure leads to significant strain delocalization which can delay the generation of catastrophic shear bands. This is resulted from the new mechanism by both forming diffuse embryonic shear bands in the thin crystalline network interface and hindering or guiding their formation and movement in thick crystalline network regions with the presence of internal stresses generated from the gradient. This work demonstrates the synergistic effects induced by the heterogeneous gradient network design in the mechanical properties of metallic glass matrix composites and may open up exciting new possibilities. Macroscopic plasticity can be improved by spatially patterning heterogeneity into "microstructures" in the homogeneous structure-less amorphous metals. By further introducing gradients in the microstructure, we can elevate the improvement to a new level. Here, we show a new metallic glass matrix composite designed with a gradient network architecture made of amorphous matrix regions and gradient crystalline boundary network regions (a). The designed gradient structure can greatly enhance the plasticity as compared to the monolithic metallic glass (MG) and nanoglass (NG) (b). The new design of the MG composite creates a hierarchical heterostructure in the spatial pattern that can effectively cause delocalization of local shear (c) and the significant delay of brittle fracture. [Display omitted] [ABSTRACT FROM AUTHOR]

• A non-local crystal plasticity model considering discrete twinning was proposed. • Size-dependent fracture behavior, plastic heterogeneity, and T-C asymmetry during micro-scaled deformation of CP-Ti were unraveled. • T-C asymmetry was enhanced with the increasing grain size and the decreasing diameter of specimen. • Ductility of CP-Ti is enhanced with grain size when D ≥0.6 mm since the concentrating stress could be relieved by abundant slip rather than cracking. • Hardening effect of twin boundaries cancelled out the softening effect near the free surface, resulting in a narrower softening layer. Titanium alloy is prominent in manufacturing of high-performance miniature devices, while size-affected plastic heterogeneity and asymmetry in micro-scaled deformation are not well understood due to its complex deformation mechanism. How the interplay among dislocation slip, deformation twinning, and strain gradient affects the size-dependent plastic heterogeneity and asymmetry is an intractable and non-eluded issue that needs to be unraveled. In this research, a non-local crystal plasticity model (NLCPM) considering discrete twins was established and implemented into a finite element framework. The proposed NLCPM successfully represented the size-dependent asymmetric mechanical response, primary and secondary twinning, and texture evolution. The size-dependent fracture behavior, plastic heterogeneity, and T-C asymmetry during micro-scaled deformation of commercial pure titanium (CP-Ti) were explored by coupling micro-tension/compression test and full-field simulation. Results showed that T-C asymmetry in flow stress was enhanced in the coarse-grained and small-diameter samples. For the sample with D ≥0.6 mm, the ductility of CP-Ti was improved with the increase of grain size as there are more prevailing twins and the concentrating stress could be relieved by the abundant slip rather than cracking. Grain-level strain is more homogeneous in compression when d was increased from 60 to 110 μm since more non-prismatic slips were activated that accommodated strain along various directions. Meanwhile, plastic strain was allocated within discrete twin bands and thus alleviated strain concentration. Furthermore, the hardening effect of twin boundaries cancelled out the softening effect near the free surface, resulting in a narrower softening layer in the coarse-grained samples compared to its grain size. With the decrease of the sample size, the proportion of the softening layer increased, while the volume fraction of twinning decreased, leading to a reduction in macroscopic stress and fracture strain. This work enhances the in-depth understanding of size-affected plastic heterogeneity and asymmetry during micro-scaled deformation of CP-Ti and supports the forming of high-quality micro components under complex deformation path. [ABSTRACT FROM AUTHOR]

Thermohydrogen processing (THP) is a potential method for enhancing the formability of titanium alloys. However, there has been no report on the deformation behavior and microstructure evolution of hydrogenated Ti65 alloys, which are new high-temperature titanium alloys used above 600 °C. In this study, we conducted a series of isothermal hot compression tests in the α+β and β phase field of Ti65 alloy specimens with varying hydrogen content to investigate the effect of hydrogen on high-temperature flow behavior and microstructure evolution. The results showed that after hydrogenation, the number of α phases in Ti65 alloy significantly decreased. δ hydride precipitates were observed in the specimen with 0.43 wt% hydrogen, resulting in an apparent refinement of its microstructure. Adding 0.25 wt% hydrogen reduced the deformation temperature by about 60 °C and increased deformation strain rate by nearly two orders of magnitude for Ti65 alloy. This improvement can be attributed to how hydrogen promotes dislocation movement, dynamic recrystallization (DRX), and dynamic recovery (DRV) during deformation. Similarly, as strain increases, the instability region on the hot processing map gradually decreases or even disappears due to broadening effects from added hydrogen; thus expanding its hot processing window further. This research deepens our understanding regarding deformation behavior while providing theoretical guidance for THP applications using Ti65 alloy. [Display omitted] • Effect of hydrogen on the hot deformation behavior of new Ti65 alloy was studied. • Hydrogenation significantly reduces the forming resistance and activation energy. • Hydrogen promotes dynamic recrystallization and refines the microstructure. • Hydrogen shrinks the instability region of the hot working maps. [ABSTRACT FROM AUTHOR]

As industrial modernization surges forward, the heat treatment industry strives for lower pollution, reduced oxidation and defects, minimized waste, and automatization. This paper reviews the mechanisms, processes, equipment, and simulations of the vacuum gas quenching technology, presenting a comprehensive account of the structure and working principle of a typical vacuum gas quenching furnace. Firstly, the mechanism of the heat transfer process, flow process, and flow–heat transfer–phase transition coupling were summarized. Then, the influences of process parameters on the mechanical properties and distortion of vacuum gas quenched workpieces, as well as the process optimization methods, were discussed. Finally, the advantages of vacuum gas quenching in energy saving, low pollution, and high efficiency were introduced, with the future development directions figured out. [ABSTRACT FROM AUTHOR]

Here, we present a case of invasive thymoma with intraluminal growth into the left and right brachiocephalic veins, superior vena cava and the right atrium. Resection of the mass, double partial upper lobe lobectomy and superior vena cava, and left and right brachiocephalic vein replacement were performed. Pathological diagnosis indicated a mixed histological pattern indicative of type B1 and type B2 thymoma, predominantly type B2 thymoma. The patient was well and without local recurrence or distal metastasis after 50 months of follow‐up. [ABSTRACT FROM AUTHOR]

Confocal three‐dimensional micro‐X‐ray fluorescence (3D‐μXRF) spectroscopy based on laboratory X‐ray tube was employed to unravel the three‐dimensional (3D) distribution of metal element (Fe) inner the paper. According the distribution of the Fe in the paper, the information covered in the printed paper could be retrieved. Before the experiment, the performance of the confocal 3D‐μXRF setup was described. The two‐dimensional (2D) mapping of printed character covered by the opaque tape and contaminated by the black ink was scanned by confocal 3D‐μXRF setup. Furthermore, 2D and 3D mapping of a printed number covered by the paper with printed character was performed by micro‐X‐ray fluorescence and confocal 3D‐μXRF setup, respectively. The scanning results indicated that confocal 3D‐μXRF was more suitable for retrieving the information covered in the paper. Furthermore, the confocal 3D‐μXRF setup has potential application on the identification of unseen letter or painting that was covered by others, such as ink. [ABSTRACT FROM AUTHOR]

In the forming process of rib-web parts, which are widely used in automobiles and aircrafts, severe streamline disorder often occurs because of unreasonable metal flow. In this study, a back-pressure-controlled forming method that can control the direction of metal flow was introduced. The effects of key parameters on metal flow were investigated, including the back-pressure value, loading mode, and back-pressure distance. The results showed that streamline defects can be avoided and the final forming load can be reduced by reasonably controlling the back-pressure parameters. The constant back-pressure mode was more conducive to achieving good forming quality compared with the linear-increased back-pressure mode. From the stress analysis of metal flow, it was demonstrated that the stress state in the rib root is changed by the back pressure, which makes the metal flow more easily along either the tangential or the radial direction. The advantages of the back-pressure-controlled forming method were confirmed by applying it to a compressor scroll rotor. [ABSTRACT FROM AUTHOR]

In this study, the influence of low-frequency vibrations on the room-temperature compression behavior of T2 copper was experimentally investigated. Upon superposing a low-frequency vibration, the forming load noticeably reduced. Among the three vibration parameters investigated, viz. frequency, amplitude, and feeding rate, vibration amplitude plays the most important role in load reduction. The superposition of stress waves can explain the mechanism of forming load reduction at low-frequency vibrations. Due to an increase in the internal stress caused by the superposition of stress waves, the required forming load reduced. The influence of the vibrations on the microstructures of compressed specimens was also discussed. Under low-frequency vibration conditions, cyclic impact loading leads to an increase in the density of dislocations and the formation of dislocation cells, which gradually evolve into new grain boundaries, causing grain refinement. [ABSTRACT FROM AUTHOR]

Residual stresses generated during hot stamping have a significant effect on the mechanical properties and dimensional stability of aluminum alloy sheet components. What is more, few studies have paid attentions to the effects of hot stamping parameters on residual stresses and the methods of reducing residual stresses during hot stamping of aluminum alloy plates with thickness around 5 mm. Hence, in this study, the effects of forming temperature, blank holder force, die entrance radius, die corner radius, and local thickening on the residual stresses of square cups were studied, by conducting both finite element simulations and experiment investigations of the hot stamping of 2024 aluminum alloy plates. The results showed that the residual stress distribution is not uniform through the thickness. Within the range of process parameters investigated in this study, increasing the forming temperature, blank holder force, and die corner radius or decreasing the die entrance radius all lead to lower values of residual stresses. Compared to flat plates, local-thickened plates can significantly reduce the residual stresses in hot stamped square cups, which is attributed to the metal supplement mechanism at the thickened locations. When the side length of the square-ring-shaped convex rib of the plate is equal to the punch width and the convex rib facing downward, lower residual stresses in square cups are obtained. The established residual stress calculation model is capable of describing the residual stress distribution in the bottom circular arc of hot stamped square cups. [ABSTRACT FROM AUTHOR]

This study aims to explore the value of a machine learning (ML) model based on radiomics features and clinical features in predicting the outcome of spontaneous supratentorial intracerebral hemorrhage (sICH) 90 days after surgery. A total of 348 patients with sICH underwent craniotomy evacuation of hematoma from three medical centers. One hundred and eight radiomics features were extracted from sICH lesions on baseline CT. Radiomics features were screened using 12 feature selection algorithms. Clinical features included age, gender, admission Glasgow Coma Scale (GCS), intraventricular hemorrhage (IVH), midline shift (MLS), and deep ICH. Nine ML models were constructed based on clinical feature, and clinical features + radiomics features, respectively. Grid search was performed on different combinations of feature selection and ML model for parameter tuning. The averaged receiver operating characteristics (ROC) area under curve (AUC) was calculated and the model with the largest AUC was selected. It was then tested using multicenter data. The combination of lasso regression feature selection and logistic regression model based on clinical features + radiomics features had the best performance (AUC: 0.87). The best model predicted an AUC of 0.85 (95%CI, 0.75–0.94) on the internal test set and 0.81 (95%CI, 0.64–0.99) and 0.83 (95%CI, 0.68–0.97) on the two external test sets, respectively. Twenty-two radiomics features were selected by lasso regression. The second-order feature gray level non-uniformity normalized was the most important radiomics feature. Age is the feature with the greatest contribution to prediction. The combination of clinical features and radiomics features using logistic regression models can improve the outcome prediction of patients with sICH 90 days after surgery. [ABSTRACT FROM AUTHOR]

The effect and mechanism of grain sizes on the tribological behavior of CoCrFeMnNi high entropy alloy (HEA) were studied by friction experiments and wear morphology analysis. Under normal low load and low sliding speed, the primary wear mechanism of the HEA samples is adhesive wear. With the increase in sliding speed, the wear mechanisms of the samples are adhesive wear and oxidation wear. The oxide layer formed under the action of friction heat of the coarse grain (CG) sample is easy to break due to the softening of the CG. With the increase of normal load and sliding speed, the wear mechanisms of the HEA samples are mainly adhesive wear, oxidation wear, and plastic deformation. The oxide layer of CG sample has many cracks, and the worn surface also has plastic deformation, which leads to the increase of friction coefficient and specific wear rate and the decrease of wear resistance. Therefore, the fine grain size HEA sample has better wear resistance than the CG sample due to its high surface strength. [ABSTRACT FROM AUTHOR]

Tracheal tumors are rare, accounting for 0.1% of all malignancies. Squamous cell carcinoma and adenoid cystic carcinoma are the two most prevalent tracheal cancers. Less than 20 cases of extramedullary plasmacytoma in the trachea and main bronchus have ever been documented in the literature, making it extremely uncommon. Although the origin of these lesions is unclear, viral pathogenesis and persistent inflammation are thought to be the main causes. Clinically, these individuals exhibit vague symptoms such as stridor, a persistent cough, dyspnea, or wheezing, making a correct diagnosis difficult. [ABSTRACT FROM AUTHOR]

The warm flow behaviors of a low alloy steel were investigated by isothermal compression tests over a broad range of temperatures (873–1173 K) and strain rates (0.001–1 s −1 ). The compression strain-stress curves showed that the flow stress at 1023 K was lower than that at 1073 K under four studied strain rates, with an abnormal stress-temperature region emerging. It was found that this abnormal phenomenon appeared in the austenite-ferrite dual-phase temperature region, while ferrite occurred at low temperatures (873, 923 and 973 K) and austenite occurred at high temperatures (1123 and 1173 K), respectively. The constitutive relationship of each phase was constructed by a dislocation model coupling Arrhenius equations, which was verified by microstructure observations. Based on single phase’s constitutive relationship, the abnormal stress-strain curves were manifested through a modified mixture law, in which a higher strain rate sensitivity of ferrite at intercritical temperatures was taken into consideration. In the end, a unified constitutive model which could adequately describe the warm flow behavior of the studied low alloy steel over the entire ranges of temperatures was developed. [ABSTRACT FROM AUTHOR]

TiO2-SiO2 composites were synthesized using cetyl trimethyl ammonium bromide (CTAB) as the structure directing template. Self-assembly hexadecyltrimethyl- ammonium bromide TiO2-SiO2/(CTAB) were soaked into silver nitrate (AgNO3) aqueous solution. The Ag-TiO2-SiO2(Ag-TS) composite were prepared via a precipitation of AgBr in soaking process and its decomposition at calcination stage. Structural characterization of the materials was carried out by various techniques including X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), N2 adsorption-desorption and ultraviolet visible spectroscopy (UV-Vis). Characterization results revealed that Ag particles were incorporated into hierarchical TiO2-SiO2 without significantly affecting the structures of the supports. Further heating-treatment at 723 K was more favorable for enhancing the stability of the Ag-TS composite. The cyclohexene oxide was the major product in the epoxidation using H2O2 as the oxidant over the Ag-TS catalysts. Besides, the optimum catalytic activity and stability of Ag-TS catalysts were obtained under operational conditions of calcined at 723 K for 2 h, reaction time of 120 min, reaction temperature of 353 K, catalyst amount of 80 mg, aqueous H2O2 (30 wt.%) as oxidant and chloroform as solvent. High catalytic activity with conversion rate up to 99.2% of cyclohexene oxide could be obtainable in water-bathing. The catalyst was found to be stable and could be reused three times without significant loss of catalytic activity under the optimized reaction conditions. [ABSTRACT FROM AUTHOR]

Controlled activation of flow units and in-situ characterization of mechanical properties in metallic glasses are facing challenges thus far. Here, vibrational loading is introduced through nanoscale dynamic mechanical analysis technique to probe vibration-accelerated atomic level flow that plays a crucial role in the mechanical behavior of metallic glasses. The intriguing finding is that high vibrational frequency induces deep indentation depth, prominent pop-in events on load–depth curves and low storage modulus, exhibiting a vibration-facilitated activation of flow units in Pd 40 Cu 30 Ni 10 P 20 metallic glass. Theoretical analysis revealed that vibration-moderated activation time-scale accelerate the activation of flow units and responsible for the above scenario. [ABSTRACT FROM AUTHOR]

A novel mechanism without involvement of vacancy or Frank loop is put forward to cast light on the formation of stacking fault tetrahedron (SFT) during plastic deformation of bulk single-crystal Cu with pre-existing parallel coherent twin boundaries (CTBs) via large scale molecular dynamics (MD) simulation. The fresh mechanism is totally different with Silcox-Hirsch mechanism and its sequelae, which supports that to produce an SFT during plastic deformation, formation of Frank loop is not essential in metals with low stacking fault energy (SFE). [ABSTRACT FROM AUTHOR]

Despite the intense interest in coherent twin boundary (CTB) of nanotwinned materials, many details of interactions between the complex dislocation (prismatic dislocation loop (PDL)) and CTB in a single crystal remain mysteries. In this study, molecular dynamics (MD) simulation of the nanoindentation on single crystal copper with CTBs has been presented. At the initial stage of nanoindentation, indenter moves downward and PDLs form. Thompson's tetrahedron notation has been adopted to scrutinize the process of PDL's formation without cross-slip and release from the indented place. Dislocations at PDLs' side edge are stair-rod partial dislocations, including two Lomer-Cottrell locks and two Hirth Locks. Then the interactions between PDL and CTB drive the migration of CTB. As a result, a parallelogram step which is bounded by Frank partial dislocations has been left, implying the formation of twinning dislocations. When the indenter moves further, the interactions repeat and twinning dislocations multiply. Our simulation results shed light on the interactions between PDL and CTB and would provide a new insight into understanding the role CTB plays during mechanical deformation. [ABSTRACT FROM AUTHOR]

Carbon nanotubes (CNTs) were considered a promising activator for persulfates due to their high electrical conductivity, large specific surface area and low toxicity. The functional groups and surface defects of CNTs could significantly affect their activation performance. In this study, CNTs with high C=O ratio and defect density (CNT-O-H) were prepared through a facile treatment of raw CNTs with HNO3 oxidation followed by calcination at 800 °C under an argon atmosphere. X-ray photoelectron spectroscopy (XPS) and Raman results showed that the C=O proportion and defect degree (ID/IG) rose to 75% and 1.53, respectively. The obtained CNT-O-H possessed a superior performance towards peroxydisulfate (PDS) activation, and the degradation efficiency of tetracycline (TC) in the CNT-O-H/PDS system was increased to 75.2% from 56.2% of the raw CNTs/PDS system within 40 min. Moreover, the activity of CNT-O-H after use could be easily recovered with re-calcination. In addition, the CNT-O-H/PDS system exhibited high adaptabilities towards wide solution pH (2–10), common coexisting substances and diverse organic pollutants. Singlet oxygen (1O2) was confirmed to be the dominant reactive oxygen species (ROS) generated in the CNT-O-H/PDS system. It was inferred that surface C=O groups and defects of CNTs were the key site to activate PDS for TC degradation. [ABSTRACT FROM AUTHOR]

The high strength of 300M steel originates from the heat treatment process after forging, but how hot deformation affects the heat-treated microstructure and mechanical properties is unclear. In this study, compression tests under different hot deformation parameters and post-deformation heat treatment experiments were carried out, and the martensite transformation process was investigated using in situ observation. The results show that the grain size of the specimen deformed at low temperature and high strain rate is smaller, and annealing twins will be formed. Both austenite grain boundaries and twin boundaries hinder the growth of martensite blocks, reducing the size of martensite units after heat treatment and thus resulting in higher yield strength. Besides, the mathematical models were established to describe the relationship between hot deformation parameters and grain size after deformation, martensite packet size and martensite block width, respectively, after heat treatment. The relationship between yield strength and hot deformation parameters was also analyzed. According to the results and models, the hot deformation parameters would be optimized more reasonably to improve the final mechanical properties of 300M steel forgings. [ABSTRACT FROM AUTHOR]

[Display omitted] • ZnO 2 was used for visible-light-induced TC degradation and E. coli inactivation. • ZnO 2 had high adaptabilities to solution pH, matrix species and water sources. • TC sensitization caused •O 2 − generation responsible for self-promoted degradation. • The photoexcitation of the hydrolysates from ZnO 2 resulted in 1O 2 generation. In this study, zinc peroxide (ZnO 2) with broad energy gap was firstly used for visible-light-induced photocatalytic degradation of tetracycline (TC) and inactivation of Escherichia coli (E. coli). A small amount of ZnO 2 (10 mg) could efficiently degrade 100 mL of 50 mg/L TC in a wide pH range (4–12), and the degradation performance was rarely suppressed by common matrix species and natural water sources. Also, 100 mg/L ZnO 2 could inactivate around 7-log E. coli cells within 60 min under visible-light irradiation. Quenching experiments and electron paramagnetic resonance (EPR) results confirmed that superoxide radical (•O 2 −) and singlet oxygen (1O 2) were the main reactive oxygen species (ROS), which were attributed to the self-sensitization of TC and the photoexcitation of released H 2 O 2 under the catalysis of Zn(OH) 2 from the hydrolysis of partial ZnO 2 , respectively. The pathways of TC degradation and processes of visible-light-induced TC degradation and E. coli inactivation were proposed and deduced in detail. This work presented the enhanced visible-light photocatalytic activities of ZnO 2 for antibiotic degradation and bacterial inactivation, and provided a deep insight into the mechanisms of visible-light-induced TC degradation and E. coli inactivation over ZnO 2. [ABSTRACT FROM AUTHOR]