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Currently, signed network representation has been applied to many fields, e.g. , recommendation platforms. A mainstream paradigm of network representation is to map nodes onto a low-dimensional space, such that the node proximity of interest can be preserved. Thus, a key aspect is the node proximity evaluation. Accordingly, three new node proximity metrics were proposed in this study, based on the rigorous theoretical investigation on a new distance metric - signed average first-passage time (SAFT). SAFT derives from a basic random-walk quantity for unsigned networks and can capture high-order network structure and edge signs. We conducted network representation using the proposed proximity metrics and empirically exhibited our advantage in solving two downstream tasks — sign prediction and link prediction. The code is publicly available. [ABSTRACT FROM AUTHOR]

Hemoperfusion is a well-developed method for removing bilirubin from patients with hyperbilirubinemia. The performance of adsorbents is crucial during the process. However, most adsorbents used for bilirubin removal are not suitable for clinical applications, because they either have poor adsorption performance or limited biocompatibility. Patients with hyperbilirubinemia usually have distinctive yellow skin, indicating that collagen, a primary component of the skin, may be an effective material for absorbing bilirubin from the blood. Based on this idea, we designed and synthesized collagen (Col) and collagen-polyethyleneimine (Col-PEI) microspheres and employed them as hemoperfusion adsorbents for bilirubin removal. The microspheres have an efficient adsorption rate, higher bilirubin adsorption capacity, and competitive adsorption of bilirubin in the bilirubin/bovine serum albumin (BSA) solution. The maximum adsorption capacities of Col and Col-PEI microspheres for bilirubin are 150.2 mg/g and 258.4 mg/g, respectively, which are higher than those of most traditional polymer microspheres. Additionally, the microspheres exhibit excellent blood compatibility originating from collagen. Our study provides a new collagen-based strategy for the hemoperfusion treatment of hyperbilirubinemia. • Two kinds of collagen-based hemoperfusion adsorbents for bilirubin removal • The microspheres exhibit higher bilirubin adsorption capacity. • The microspheres display low protein adsorption and outstanding compatibility. [ABSTRACT FROM AUTHOR]

Hemoperfusion is a well-developed method for removing bilirubin from patients with hyperbilirubinemia. The performance of adsorbents is crucial during the process. However, most adsorbents used for bilirubin removal are not suitable for clinical applications, because they either have poor adsorption performance or limited biocompatibility. Patients with hyperbilirubinemia usually have distinctive yellow skin, indicating that collagen, a primary component of the skin, may be an effective material for absorbing bilirubin from the blood. Based on this idea, we designed and synthesized collagen (Col) and collagen-polyethyleneimine (Col-PEI) microspheres and employed them as hemoperfusion adsorbents for bilirubin removal. The microspheres have an efficient adsorption rate, higher bilirubin adsorption capacity, and competitive adsorption of bilirubin in the bilirubin/bovine serum albumin (BSA) solution. The maximum adsorption capacities of Col and Col-PEI microspheres for bilirubin are 150.2 mg/g and 258.4 mg/g, respectively, which are higher than those of most traditional polymer microspheres. Additionally, the microspheres exhibit excellent blood compatibility originating from collagen. Our study provides a new collagen-based strategy for the hemoperfusion treatment of hyperbilirubinemia. • Two kinds of collagen-based hemoperfusion adsorbents for bilirubin removal • The microspheres exhibit higher bilirubin adsorption capacity. • The microspheres display low protein adsorption and outstanding compatibility. [ABSTRACT FROM AUTHOR]

• The passive film properties of Ce-added AlCoCrFeNi 2.1 alloys are studied for the first time. • Ce addition is not conducive to corrosion resistance of the AlCoCrFeNi 2.1 alloy in H 2 SO 4 solution. • Ce increases the doping density and reduces the proportion of Cr oxides in the passive film. Eutectic high-entropy alloys (EHEAs), represented by AlCoCrFeNi2.1, are considered to be promising materials. However, the study of the corrosion behavior of EHEAs remains limited, which hinders further development. This study investigated the effect of Ce addition on the electrochemical behavior and passive film properties of AlCoCrFeNi 2.1 EHEAs in H 2 SO 4 solutions. The results show that the addition of Ce changed the properties of the passive film formed on the alloys, resulting in reduction in the proportion of Cr 2 O 3 , and thereby reduced the corrosion resistance. Moreover, a higher Ce content in the EHEAs was found to correspond to a more pronounced deterioration in corrosion resistance. Compared with the film formed at 0.2 V vs SCE , the film formed at 0.5 V vs SCE exhibited more optimal physicochemical properties, leading to a decrease in the passive current density. Notably, Ce was absent in the film formed at 0.2 V vs SCE , but present at 0.5 V vs SCE. [ABSTRACT FROM AUTHOR]

Sonodynamic therapy (SDT) is a new treatment method combining low-intensity ultrasound with sono-sensitizers, which has the advantages of non-invasiveness as well as low side effects, and has a very broad application prospect in antitumor clinics because of its high penetration ability to tissues and hence can be used to treat some deep lesions. Nevertheless, the clinical application of SDT is seriously affected by factors such as hypoxia of tumor microenvironment and low bioavailability of sono-sensitizers, and its in vivo tumor suppression efficiency is far from the desired expected effect. Metal-organic frameworks (MOFs) are new hybrid crystalline porous materials synthesized using metal nodes and organic ligands. With a large specific surface area, adjustable and modifiable structures, good biodegradability, high drug loading, controlled drug release, and strong targeting, MOF can serve as a powerful multifunctional platform to effectively solve some of the problems faced in SDT. In this review, we present different types of MOFs as super-efficient sono-sensitizers carriers and the latest research progress in the area of MOFs having sonosensitizers as organic ligands to enhance SDT, using different types of sono-sensitizers as an entry point. Finally, we summarize some pertinent issues in ultrasound dynamics in potential practice and the future development prospect of ultrasound dynamics. In this review, we present different types of MOFs as super-efficient sonosensitizers carriers and MOFs with sonosensitizers as organic ligands to enhance SDT, using different types of sonosensitizers as an entry point. Finally, we summarize some pressing issues in ultrasound dynamics in clinical practice and look into the future development of ultrasound dynamics. [Display omitted] • Several of MOFs as super-efficient sonosensitizers carriers and MOFs with sonosensitizers were concluded. • The possible SDT mechanism was proposed. • The current promising application and its challenge in SDT were suggested. [ABSTRACT FROM AUTHOR]

Abstract To test the tunability of charge transfer (CT)-based BODIPY photosensitizers in generating singlet oxygen (1Δ g), twelve meso -phenyl-BODIPY (donor-acceptor) type compounds have been synthesized and fully characterized, in which the phenyl moiety is modified with respective 0, 1, 2 and 3 methoxy groups to increase its electron-donating ability. The UV-Vis absorption spectra, fluorescence emission spectra, fluorescence quantum yield, fluorescence lifetime, excited triplet state formation, and singlet oxygen formation properties are measured. DFT quantum chemical computation is also carried out to explain the experiments. The occurrence of intra-molecular CT is confirmed by UV-Vis absorption, fluorescence properties and quantum chemical computation. The triplet excited state formation is evidenced by laser flash photolysis technique. The quantitative photosensitized singlet oxygen formation is demonstrated by DPBF (diphenylisobenzofuran) chemical trapping method. This type of BODIPY CT photosensitizers show good tunability in generating singlet oxygen (1Δ g). When the number of methoxy group on the donor is increased (so that CT is enhanced), the efficiency of singlet oxygen generation becomes higher from 0.070 to 0.30. When solvent polarity is increased (CT is also enhanced), the efficiency of singlet oxygen generation is also increased significantly. The increase in singlet oxygen generation is accompanied by the decrease in fluorescence quantum yield and fluorescence lifetime values. These facts show that a higher CT efficiency in a simple phenyl-BODIPY donor-acceptor conjugate can lead to significant higher quantum yield of singlet oxygen generation. These results are useful in designing novel CT-based heavy-atom-free photosensitizers for photodynamic therapy of tumor. Graphical abstract Singlet oxygen formation yield of (CH 3 O) n -phenyl-BODIPY donor-acceptor conjugate is proportional to the number of methoxy group. Image 1 Highlights • Eight new charge transfer (CT)-based BODIPY photosensitizers are synthesized. • The CT efficiency is adjusted by adding 0 to 4 methoxys on meso-phenyl. • The increase in either the number of methoxys or solvent polarity enhances 1O 2 formation. • Higher CT efficiency favors higher singlet oxygen generation quantum yield. [ABSTRACT FROM AUTHOR]

Highlights • Bulk Al-doped carboxymethyl cellulose aerogels were fabricated via a facile slow-gel method and freeze-drying technology. • Compared with pure silica aerogels, the Al-doped carboxymethyl cellulose aerogels possed better weight-bearing capacity. • The Al-doped CMC aerogels exhibited excellent flame retardancy and could be rated V-0 regarding UL-94 testing. Abstract Bulk Al-doped carboxymethyl cellulose aerogels were obtained via a facile slow-gel method and freeze-drying technology. In this method, the cross-linker Al3+ was released slowly and completely with enough d -(+)-gluconic acid δ -lactone as a sustained-release agent. Depended on controlled releasing of Al3+, the reaction speed between Al3+ and carboxyl groups was controlled and Al3+ was well-distributed in the aerogels. The coordination type between Al3+ and carboxymethyl cellulose was the bidentate bridging coordination. By adjusting the amount of Al3+ and the degree of substitution of carboxymethyl cellulose, interconnected network and closely packed sheet-like structure presented, respectively. According to the nitrogen adsorption-desorption isotherms, the aerogels were a kind of mesoporous material with pore blocking or cavitation. In addition, the aerogels exhibited outstanding weight-bearing capacity and excellent flame retardancy. This work provided a valuable reference for doping metal ions into polysaccharide aerogels and expanding the application fields of aerogels. [ABSTRACT FROM AUTHOR]

A novel fiber-optic hydrogen sensor including Pt/WO 3 sensing material with a microporous structure is proposed and experimentally demonstrated with improved performance. The proposed Pt/WO 3 sensing material is realized by introducing metal-organic frameworks (MOFs) as templates. The mesoporous structure of the ZIF-8 template improves the reactive sites of hydrogen sensitive materials with hydrogen. Hydrogen sensors were fabricated by combining the synthesized material with Fiber Bragg Gratings (FBGs) and the performance of hydrogen sensors was investigated. The experimental results show that the hydrogen sensitivity of the FBG with ZIF-8 synthesized Pt/WO 3 has been increased to 0.075 pm/ppm, which is twice that without ZIF-8 synthetization. The stability and the response speed are also significantly improved. The introduction of microporous MOFs templates into Pt/WO 3 sensing material will greatly accelerate the wide application of Pt/WO 3 -based fiber optic hydrogen sensors on hydrogen leakage detection. • A promising porous Pt/WO 3 synthesized based on ZIF-8 is proposed and demonstrated. • The porous structure provides more active sites and diffusion channels for H 2. • The sensor coated with the porous Pt/WO 3 showed excellent response sensitivity. • The porous Pt/WO 3 sensor exhibited excellent response efficiency and stability. [ABSTRACT FROM AUTHOR]

We synthesized three 1,3,5,7-tetramethyl-BODIPY ( 1a , 2a , 3a ) and three 3,5-dimethyl-BODIPY ( 1b , 2b , 3b ) photosensitizers, in which the meso position was modified by different para -aminophenyl groups. The singlet oxygen generation and photophysical properties of the BODIPYs were studied by UV-vis absorption spectra, fluorescence emission spectra methods in various solvents. It was found that these BODIPY derivatives were environment-sensitive and fluorescent photosensitizers, which show high efficiency for generating singlet oxygen in medium polar environments but little photoactivity in polar and non polar solvents. In the mean time, they are highly fluorescent in nonpolar solvents but much less emissive in polar solvents, ICT emission occurs in medium polar solvents and correlated with singlet oxygen formation efficiency. The results are explained by PCT (photoinduced charge transfer) mechanism. The presence of the methyl groups at 1 and 7 positions disables the rotation of the phenyl ring, and therefore, the corresponding BODIPY 1a , 2a , and 3a were characterized by significant higher singlet oxygen generation efficiency and fluorescence quantum yield than that of BODIPY 1b , 2b , and 3b . [ABSTRACT FROM AUTHOR]

meso -phenyl and meso -naphthyl substituted BODIPY derivatives were synthesized as singlet oxygen photosensitizers. Strengthening the electron donating ability of the phenyl or naphthyl by attaching OCH 3 or OH group makes these BODIPYs efficiently generate singlet oxygen in polar solvents accompanied by strong fluorescence quenching. The BODIPYs exhibited higher fluorescence quantum yields in non polar solvents, but became much less emissive in polar solvents. The results are explained by the involvement of photoinduced electron or charge transfer process in the lowest lying excited singlet state (S 1 ). These results indicate that these BODIPY dyes can be potential singlet oxygen photosensitizers for the application in PDT and theranostics. [ABSTRACT FROM AUTHOR]

In the field of social network analysis, network evolution and event detection are the main current challenges. To meet them, current research work proposed many different models based on different network evolutions, and then evaluated the simulation results with different similarity indexes. However, the previous work usually had three problems: (1) Each method is only designed for a particular network; (2) There are many network statistics, so the evaluation on the performances of network models lacks an unified platform; (3) Without considering the temporal information, it is hard to track the network evolution and detect events. This paper proposes an event detection method for social networks based on link prediction, which can also evaluate the volatility of different networks. The main contributions are as follows. (1) The volatility of the network evolution can be effectively reflected on the similarity index corresponding to a good link prediction performance. (2) Inspired by link prediction, a similarity computing algorithm ( SimC ) is proposed to compute the similarity of networks. (3) Based on the output of SimC , the volatility of network evolution is evaluated and an event detection algorithm ( EventD ) is proposed. The experimental results show that the proposed method can effectively solve the problem of tracking network evolutions and detecting events. [ABSTRACT FROM AUTHOR]

[Display omitted] • meso -RNH (R = alkyl and phenyl) substituted BODIPY are prepared. • meso -RNH leads to large blue shift of both absorption and emission wavelength. • meso -RNH induces big decrease in fluorescence quantum yield and lifetime values. • RNH leads to significant increase in singlet oxygen formation quantum yield. • Photoinduced charge transfer (PCT) mechanism is responsible for the observations. meso -RNH (R = C 3 H 7 , C 4 H 9 , PhCH 2 , H, and Ph) substituted BODIPY compounds have been prepared to examine their photophysical properties and photosensitizing abilities. We have measured the UV–vis absorption, steady state and time resolved fluorescence, excited triplet state formation using laser flash photolysis, singlet oxygen generation ability using chemical trapping method. The results show that the presence of meso -RNH leads to large blue shift of absorption and emission wavelength, remarkable decrease in fluorescence quantum yield and lifetime values, and significant increase in singlet oxygen formation quantum yield. Quantum chemical calculation also reveals the photoinduced charge transfer (PCT) mechanism. We conclude that property changes are due to: 1) S 0 and S 1 geometry, 2) ground state structural isomerization, and 3) intramolecular PCT. These results and mechanisms are helpful for designing new functional materials. [ABSTRACT FROM AUTHOR]

Super-microporous micelle-templated platinum on silica catalysts were successfully prepared by an improved one-pot procedure, using a water/acetonitrile/ n -dodecylamine mixture. The catalyst showed high surface area and narrow pore size and was further characterized by powder X-ray diffraction and inductively coupled plasma mass spectrometry. The unique super-microporous materials were proven to be highly active for the microwave-assisted hydrosilylation reaction of terminal alkenes or alkynes using dichloromethylsilane as silicon source. The super-microporous structure was beneficial for the control of hydrosilylation regioselectivity, as the selectivity to the β-adduct reached 99%. Moreover, the catalyst could be easily recovered by simple filtration and re-used seven times without appreciable loss of activity and selectivity. [ABSTRACT FROM AUTHOR]

A method for preparing hydrophobic silica aerogel with kaolin as raw material and dried at ambient pressure is proposed. The process of preparing the aerogel consists of three stages including activation of kaolin, preparation of wet silica gel and hydrophobic modification. The effects of hydrochloric acid concentration on the physical properties and structures of the silica aerogel are investigated. Effects of removing Na + from the solvent solution on the structure and properties of aerogel are discussed. The aerogel obtained with kaolin has comparable structure and property to those prepared with other more expensive silica sources. The newly proposed method is expected to simplify the manufacturing technique, to shorten the production time and to reduce the costs of silica aerogel. [ABSTRACT FROM AUTHOR]

The pathwise method is one of the approaches to calculate the option price sensitivities by Monte Carlo simulation. Under the general diffusion process, we usually use the Euler scheme to simulate the path of the underlying asset, which requires small time spaces to assure the convergence. The adjoint method can be used to accelerate the calculation of the Greeks in such case. However, it needs to store the intermediate information along the path. In this paper, we propose to use the block simulation to further accelerate the calculation. Block simulation can be seen as an extension of the common Monte Carlo simulation. It is simple to implement, without any extra work and loss in accuracy. It also has the flexibility on the block division, fitting to the computation environment. Moreover, we use the extended forward-path method along with the real time calculation strategy to do the memory reduction so that it can be combined with the adjoint method better. The numerical tests show our method can accelerate the adjoint method by several times. Our method is relatively even more efficient in the high-dimensional case. [ABSTRACT FROM AUTHOR]

Abstract: The forward-path method is one of the effective memory reduction approaches in pricing multi-asset American-style options by the Monte Carlo simulation. However, when the underlying assets follow a general diffusion process, it would be difficult to apply this method. In this paper we propose a simple and effective method, which applies the Milstein–Taylor explicit and implicit schemes and makes it possible to apply the forward-path method under general diffusion processes. It preserves the advantage of high reduction with relatively low cost of the forward-path method. Moreover, it works as a plug-in and one can flexibly substitute the schemes with different ones for different problems. It is proven that our method can conveniently restore the simulated path with strong convergence order . The numerical results indicate our method has high pricing accuracy and efficiency. [Copyright &y& Elsevier]

• ChS-Cur polymeric micelles were prepared by radical polymerization. • The micelles showed a good dispersion stability as its high negative zeta potential. • In vitro cytotoxicity tests showed that the ChS-Cur micelles were non-cytotoxic. • The micelles micelles had redox sensitivity for drug release at tumor sites. Chondroitin sulfate-curcumin (ChS-Cur) polymeric micelles derived from oxidized Chondroitin sulfate (ChS), Curcumin (Cur) and Bis-acrylamide cysteine (BAC) were prepared by radical polymerization. The morphology, Zeta potential, cytotoxic and drug release behavior were explored. ChS-Cur polymeric micelles hold a spherical structure with a particle size of about 250 nm, and micelles showed a good dispersion stability. Release studies showed that the controlled release profile of drug was obtained and the micelles had redox sensitivity. In vitro cytotoxicity studies showed that the ChS-Cur micelles were non-cytotoxic. [ABSTRACT FROM AUTHOR]

Abstract: The platinum (Pt) particle electrocatalysts were fabricated by a surfactant-free, electro-deposition technique in the cyclic voltammetric mode for electro-oxidation of ammonia in aqueous solutions. The hierarchical Pt nanoparticles with various morphologies, including sheet-, flower-, prickly sphere- and cauliflower-like shapes, were obtained by controlling the electrodepositing parameters. The amount of Pt loading was determined by an inductively coupled plasma method, and the electrocatalytic activity of the prepared nano-Pt electrocatalysts for the ammonia oxidation was characterized by cyclic voltammetry. The results showed that there is a remarkable effect of the surface morphology of Pt particles on the electrocatalytic activity. In particular, the hierarchical Pt particles have a much higher electrocatalytic activity for the ammonia oxidation than the smooth, spherical Pt particles. The improved electrocatalytic activity is attributed not only to the large electrochemically active surface area (ECSA) achieved, but also to the high electrocatalytic activity per unit ECSA. Electro-deposition technique provides a promising alternative to fabricate high-performance electrocatalysts for oxidation of ammonia in aqueous solutions. [Copyright &y& Elsevier]

Abstract: Submicron-sized cuprous oxide crystallites was prepared by electrodeposition, and polyethylene glycol (PEG) was introduced to improve the dispersity of crystallites. Transmission electron microscopy (TEM) and scanning electronic microscopy (SEM) were applied to characterize its crystal structure and morphology. Based on the analysis, it was found that PEG can affect the growth mode of cuprous oxide crystallites, which improves of the dispersity of the crystallites. The growth of cuprous oxide crystallites without PEG presents obvious aggregation dominant, while diffusion becomes the dominant mechanism when PEG is introduced into the electrolyte. The photo transmission character of cuprous oxide crystallites was measured by UV–vis spectrophotometer, and the calculated band gap energy of which is approximately 2.17eV. The photoelectrochemical property of the crystallites was also characterized with the current–potential responses to a linear potentiodynamic scan under chopped illumination, and it is found that the photocurrent of the cuprous oxide crystallites electrodeposited with PEG is obviously larger than the one without PEG. [Copyright &y& Elsevier]

Abstract: Three conventional complexing agents, including lactic acid, citric acid and EDTA, are applied in the electrodeposition of microcrystalline cuprous oxide (Cu2O) film on indium tin oxide glass substrate. Both scanning electron microscopy and X-ray diffraction have been performed to characterize the morphology and texture of microcrystalline Cu2O film. It is found that the stability constant of copper-based complex compound can obviously influence the deposition overpotential of Cu2O, and the overpotential can significantly alter the growth priority of different planes, which results in oriented growth of Cu2O grains. The quantitative relationships between the stability constant and the deposition overpotential of different complexing agents, as well as the relationship between the overpotential and the formation energy of microcrystalline cuprous oxide''s (110), (111) and (200) planes are calculated, respectively. [Copyright &y& Elsevier]

Abstract: Nanoplate-based copper sulfide (CuS) hierarchical hollow spheres have been successfully synthesized using the spontaneous oil droplets as the templates in a two-phase system. In this approach, the poorly crystallized CuS hollow spheres with an average diameter of about 1μm can be obtained at a low temperature and then grow into the hierarchical CuS hollow spheres composed of nanoplates through a recrystallization growth process at a higher temperature. Furthermore, the growth process of the nanoplates of the hierarchical CuS hollow spheres can be controlled by changing the ripening time. In addition, the photocatalytic activity of the hierarchical CuS hollow spheres has been evaluated by the degradation of methylene blue solution in the presence of hydrogen peroxide under natural light, showing that the as-prepared hierarchical CuS hollow spheres exhibit high photocatalytic activity for the degradation of methylene blue (MB). [Copyright &y& Elsevier]

Abstract: Identifying new uses for glycerol, a waste of biodiesel production from transesterification of vegetable oils, is of great current interest. Towards this end, catalytic oxidation of glycerol to produce the high-value chemical dihydroxyacetone (DHA) is a promising approach. The challenge, however, is the relatively complex reaction network. The kinetics of the complete glycerol oxidation network over Pt–Bi/C catalyst was investigated systematically in this study. Based on a detailed reaction mechanism including adsorption/desorption and reaction steps on the catalyst surface, a kinetic model was developed. To overcome the difficulty in finding the global optimum in the model, the full complex network was decomposed into five progressively larger sub-networks with different intermediates as initial reactants. The corresponding reactions starting with these initial reactants were conducted and the collected data were used to fit the kinetic model for each sub-network. The experimental and calculated results were in good agreement and the kinetic parameters for each step were obtained. These results can be used to design and develop new appropriate catalysts with high stability, activity and selectivity for DHA. In fact, this approach is a powerful tool for the microkinetic study of other complex reaction networks as well. Based on the concentration of each component and rate expression of each reaction step, a simplified network was identified and studied. The parameters thus obtained can be used to develop reactor models which could be used to determine the optimum operating reaction conditions for maximizing the yield of desired product DHA. The effective conversion of glycerol to high value chemical will increase the profitability of biodiesel production, a promising renewable energy source. [Copyright &y& Elsevier]

Abstract: CuS hollow spheres have been synthesized through a facile microemulsion template route at room temperature using copper naphthenate as metal precursor and thioacetamide as the source of S2−. In our method, the metal precursor and sulfur source dissolved in two different phases; the reaction only occurs at oil/water interface. Thus, hollow spheres can be fabricated more easily. The CuS hollow spheres prepared at room temperature are loose aggregates which are composed of small primary nanoparticles. To form stable hollow spheres it is a key to ensure the growth of nanoparticles at initial stage of reaction by a high interfacial reaction rate. So the reaction conditions that can control interfacial reaction rate are important factors for forming hollow spheres. [Copyright &y& Elsevier]

Abstract: A steel corrosion sensor based on fibre Bragg gratings (FBGs) has been developed and tested in this paper. The steel corrosion sensor has been formed by electroplating a Fe–C film on a metallized FBG. The coated FBG sensors have been tested in cabinets in which the availability of chloride ions and oxygen are controlled. The microstructural changes have been investigated by optical microscopy and SEM imaging. The FBG spectra are collected by a spectrometer. The results show that the spectra change, the wavelength shift, and the occurrence of multiple peaks are related to the corrosion degree of the Fe–C film. [Copyright &y& Elsevier]

Abstract: Zinc oxide (ZnO) hollow microspheres were prepared by templates of surfactant spheres in mercury-media for the first time. Field emission scan electron microscope (FESEM), X-ray diffraction (XRD), infrared spectra (IR) and N2 adsorption–desorption analysis were used to characterize morphologies and structure features of the products. The obtained ZnO hollow microspheres are amorphous, 1–3μm in diameter and 70–140nm in wall thickness. After heat treatment at 500°C for 2h, the amorphous ZnO hollow spheres transform to hexagonal wurtzite structure ZnO, and retain hollow sphere morphologies. During the growth of ZnO hollow microspheres, Zn is oxidized at mercury/air interface and the formed ZnO nanoparticles are assembled on the surface of surfactant spheres. PEG plays an important role for the synthesis of ZnO hollow microspheres. [Copyright &y& Elsevier]

Abstract: Influence of three post treatment techniques including water washing, ethanol washing and n-butanol heterogeneous azeotropic distillation on the structure, dispersity and luminescence properties of YAG:Ce nanophosphor were comparatively studied. In contrast to the first two processing techniques, n-butanol azeotropic distillation prevents powders from conglobation due to larger n-butanol molecules, longer butoxy groups and a more complete replacement of residual water in the precipitate. The phosphor from azetropic distillation exhibits excellent luminescence properties with higher emission intensity than those from water washing and ethanol washing. [Copyright &y& Elsevier]

Abstract: (Y1− x Ln x )3Al5O12:Ce (Ln3+=Gd3+, La3+) phosphors were synthesized by in situ esterification. The effects of Gd3+ and La3+ ions on structure and luminescence of YAG:Ce were investigated. For Gd3+-doped YAG:Ce, when doping concentration increased beyond 50mol%, GdAlO3 phase appeared. For La3+-doped YAG:Ce, as doping concentration increased beyond 20mol%, YAG phase completely disappeared and LaAlO3 phase emerged. As the doping concentration of Gd3+ and La3+ increased, the maximum emission band showed red shift. Because radii of Gd3+ and La3+ were larger than that of Y3+, Gd3+ and La3+ replacement distorted YAG structure. More defects are formed in (Y1− x Ln x )3Al5O12:Ce, which acts as quenching center. Therefore, emission intensity of (Y1− x Ln x )3Al5O12:Ce was lower than YAG:Ce and luminescent lifetime of (Y1− x Ln x )3Al5O12:Ce was shorter than YAG:Ce. [Copyright &y& Elsevier]

Abstract: Honeycomb sandwich structure combines high flexural rigidity and bending strength with low weight. Sandwich construction plays an increasing role in industry, and sandwich structural designing is an available method for sandwich structures. However, the absence of the design variable is the principal problem of composite sandwich construction. In this paper, the structure and mechanical properties of honeycomb sandwich panels are introduced. The weight ratio range of honeycomb core that is deduced on the basis of optimum mechanical properties offer a principle foundation for designing the structure of honeycomb sandwich panels. The satisfying weight condition of the honeycomb core weight is 50–66.7% of the weight of the whole honeycomb sandwich panels by theoretical analysis. Based on that conclusion, the honeycomb sandwich panels were designed and the results were verified by further experiments. Agreement between the theoretical values of the sample and experimental results is good. [Copyright &y& Elsevier]

A method of laying a layer of humid porous medium on roof to gain free cooling effect by passive water evaporation is proposed. Numeric model for simulating cooling effect is built with the help of experimental results of physical properties for humid porous medium, which shows advantage over analytical solutions because of the supposition of constant physical properties in the latter. Through the comparison between simulated and experimental results, the model is validated. And the method of evaporation cooling effect with humid porous medium on the roof is tested to be feasible. [Copyright &y& Elsevier]

[Display omitted] • Electrochemical technologies for heavy metal recovery are systematacially reviewed. • Four typical electrochemical recovery methods are classified for the first time. • Mechanisms of different electrochemical recovery technologies are fully discussed. • Influence factors of improving recovery efficiency for heavy metals are analyzed. • Electrochemical high value-added reutilization of heavy metal are prospected. Wastewater treatment for heavy metals is currently transitioning from pollution remediation towards resource recovery. As a controllable and environment-friendly method, electrochemical technologies have recently gained significant attention. However, there is a lack of systematic and goal oriented summarize of electrochemical metal recovery techniques, which has inhibited the optimized application of these methods. This review aims at recent advances in electrochemical metal recovery techniques, by comparing different electrochemical recovery methods, attempts to target recycling heavy metal resources with minimize energy consumption, boost recovery efficiency and realize the commercial application. In this review, different electrochemical recovery methods (including E-adsorption recovery, E-oxidation recovery, E-reduction recovery, and E-precipitation recovery) for recovering heavy metals are introduced, followed an analysis of their corresponding mechanisms, influencing factors, and recovery efficiencies. In addition, the mass transfer efficiency can be promoted further through optimizing electrodes and reactors, and multiple technologies (photo-electrochemical and sono-electrochemical) could to be used synergistically improve recovery efficiencies. Finally, the most promising directions for electrochemical recovery of heavy metals are discussed along with the challenges and future opportunities of electrochemical technology in recycling heavy metals from wastewater. [ABSTRACT FROM AUTHOR]

The lack of research on the hydrolysis and calcination processes in the low-concentration Ti-W-H 2 SO 4 system has been an obstacle to the recovery of titanium from the H 2 SO 4 waste solution. This study proposes a feasible process for the synthesis of Ti/W powders from unconcentrated H 2 SO 4 solutions containing Ti and W. The study explores the kinetics of hydrolysis and the influences of process parameters on the properties of Ti/W powders. Under optimum conditions, a Ti/W powder with a total TiO 2 and WO 3 content of 97.49%, and a specific surface area of 89.40 m2/g was obtained. The resynthesized SCR catalysts prepared using Ti/W powder demonstrated good denitrification activity. The hydrolysis efficiency of Ti conforms to the Avrami model. The homogeneous nucleation reaction occurred during hydrolysis with an activation energy of 191.97 kJ/mol. Based on the kinetic research, the temperature and time can be adjusted to fine-tune the microscopic morphology, pore properties, and particle size of the powder particles. This study demonstrates an effective technique for the stable preparation of high-value products from low-concentration Ti-W-H 2 SO 4 solutions, which contributes to eco-friendly resource recovery. [Display omitted] • A feasible process to prepare Ti/W powders from unconcentrated H 2 SO 4 solutions with Ti and W was proposed. • The hydrolysis efficiency of Ti conforms to the Avrami model. • The kinetics of the hydrolysis and calcination processes were investigated. • Resynthesized SCR catalysts from Ti/W powder show good denitrification activity. [ABSTRACT FROM AUTHOR]

Using nanocatalysts to catalyze water electrolysis for hydrogen production is an ideal solution to address the energy crisis. The most well-adopted fabrication methods for nanocatalysts are tube furnace annealing, Hydrothermal method, etc., hardly satisfying the trade-off among coarsening, dispersity, and particle size due to mutual restrictions. Herein, a universal, ultrafast and facile cellulose nanometer whiskers-high temperature shock (CNW-HTS) method was reported for fabricating a library of ultrafine metal nanoparticles with uniform dispersion and narrow size distribution. The metal-anchor functional groups in CNW (i.e., –OH and –COOH) and the characteristics of the HTS method for ultrafast heating and powerful quenching synergistically contribute to the successful synthesis of metal nanoparticles. As an initial demonstration, the as-prepared Pt nanocatalyst (η10 ​mA ​cm−2 ​= ​51.8 ​mV) shows more excellent catalytic hydrogen evolution reaction (HER) performance than the Pt catalyst prepared in the tubular furnace (η10 ​mA ​cm−2 ​= ​169.4 ​mV). This rapid and universal CNW-HTS method can pave the way for nanomanufacturing to produce high-quality metal nanoparticles, thereby expanding applications of energy conversion and electrocatalysis. [ABSTRACT FROM AUTHOR]

Sustainable aviation fuels (SAF) are a major research focus in the refining and aerospace industries. However, the liquid-phase separation and low-temperature starting performance of ethanol-based fuels are a difficult problem for SAF development. In this study, a biomimetic hydrogen bond strategy, inspired by the DNA structure, was used to stably disperse an ethanol kerosene-based nanofluid fuel. Carbonized poly [cyclotriphosphazene-co-(4,4′-sulfonyldiphenol)] (CPZS) nanoparticles (containing hydrogen bond acceptor) were synthesized to improve the dispersion and sedimentation and inhibit absorption of water by the fuel, allowing the proportion of ethanol to be increased to 50 wt%. This fuel had an unprecedented shelf-life of 140 days (representing an extension of 560%). The hydrogen bonding between CPZS and the ethanol/kerosene hybrid fuel was verified. The CPZS and ethanol/kerosene hybrid fuel exhibited excellent stability and dramatically enhanced the ignition performance, with the ignition delay time declining to 243 ms at an ambient temperature of 975 °C (821.0 ms for E50/K50). Compared with pure kerosene fuel, the CO 2 emissions of the E50/K50 hybrid fuel combustion decreased by 19.13%. This study provides a new biomimetic strategy based on hydrogen bonding for preparing ethanol-based fuel with a long shelf-life, enabling the possibility of directly using biomass ethanol in SAF. [Display omitted] • A biomimetic hydrogen bond strategy was proposed to stably disperse an ethanol kerosene-based nanofluid fuel. • CPZS-700/(E50/K50) hybrid fuel had an unprecedented shelf-life of 140 days. • The ethanol/kerosene fuel dramatically enhanced the ignition performance with the addition of CPZS. • The CO 2 emissions of the CPZS-700/(E50/K50) hybrid fuel combustion decreased by 19.13%. [ABSTRACT FROM AUTHOR]

As a graph data mining task, graph classification has high academic value and wide practical application. Among them, the graph neural network-based method is one of the mainstream methods. Most graph neural networks (GNNs) follow the message passing paradigm and can be called Message Passing Neural Networks (MPNNs), achieving good results in structural data-related tasks. However, it has also been reported that these methods suffer from over-squashing and limited expressive power. In recent years, many works have proposed different solutions to these problems separately, but none has yet considered these shortcomings in a comprehensive way. After considering these several aspects comprehensively, we identify two specific defects: information loss caused by local information aggregation, and an inability to capture higher-order structures. To solve these issues, we propose a plug-and-play framework based on C ommute T ime D istance (CTD), in which information is propagated in commute time distance neighborhoods. By considering both local and global graph connections, the commute time distance between two nodes is evaluated with reference to the path length and the number of paths in the whole graph. Moreover, the proposed framework CTD-MPNNs (C ommute T ime D istance-based M essage P assing N eural N etworks) can capture higher-order structural information by utilizing commute paths to enhance the expressive power of GNNs. Thus, our proposed framework can propagate and aggregate messages from defined important neighbors and model more powerful GNNs. We conduct extensive experiments using various real-world graph classification benchmarks. The experimental performance demonstrates the effectiveness of our framework. Codes are released on https://github.com/Haldate-Yu/CTD-MPNNs. [ABSTRACT FROM AUTHOR]

Graph Neural Networks (GNNs) have been successfully applied to graph-level tasks in various fields such as biology, social networks, computer vision, and natural language processing. For the graph-level representations learning of GNNs, graph pooling plays an essential role. Among many pooling techniques, node drop pooling has garnered significant attention and is considered as a leading approach. However, existing node drop pooling methods, which typically retain the top-k nodes based on their significance scores, often overlook the diversity inherent in node features and graph structures. This limitation leads to suboptimal graph-level representations. To overcome this, we introduce a groundbreaking plug-and-play score scheme, termed MID. MID comprises a M ultidimensional score space and two key operations: fl I pscore and D ropscore. The multidimensional score space depicts the significance of nodes by multiple criteria; the flipscore process promotes the preservation of distinct node features; the dropscore compels the model to take into account a range of graph structures rather than focusing on local structures. To evaluate the effectiveness of our proposed MID, we have conducted extensive experiments by integrating it with a broad range of recent node drop pooling methods, such as TopKPool, SAGPool, GSAPool, and ASAP. In particular, MID has proven to bring a significant average improvement of approximately 2.8% over the four aforementioned methods when tested on 17 real-world graph classification datasets. Code is available at https://github.com/whuchuang/mid. [ABSTRACT FROM AUTHOR]

• EMD- and ICA-based method has been introduced to process the data from FOG. • The combined method shows improvement on trajectory optimization. • The combined method shows improvement on deviation reduction. • The combined method is powerful on processing obvious bumps and shocks. The angular velocity data of Fiber-Optic Gyro (FOG) are key signals to trajectory calculation for a FOG-based curve measuring system. The shocks from bumps on the route will contaminate the signal and finally drift the calculated trajectory. An optimized processing strategy on the contaminated signals is able to suppress the drifting with almost no trajectory distortion. In this paper, the signals from FOG have been processed by using median filtering (MF), Empirical Mode Decomposition (EMD) and the combined method of EMD and Independent Component Analysis (ICA). The experiments are performed under different conditions. The frequency spectrum and deviation study before and after processing have been investigated to compare the performance of the employed strategies. The combined EMD and ICA method has shown the best performance on trajectory optimization and error suppression with almost no distortion. [ABSTRACT FROM AUTHOR]

Halloysite nanotubes (HNTs) are the natural clay mineral with a tubular structure, which can be used as the nanocontainer for loading corrosion inhibitor. In this work, Na 2 MoO 4 was loaded into HNTs (defined as “Na 2 MoO 4 -HNTs”) through vacuum negative pressure method. In order to control the release rate of Na 2 MoO 4 from Na 2 MoO 4 -HNTs, the insoluble CaMoO 4 complex was introduced at the end of tubes through the interaction between Na 2 MoO 4 and Ca 2+ to obtain Ca-Na 2 MoO 4 -HNTs. The surface morphology was investigated by transmission electron microscope (TEM), and the release behavior was determined by UV–vis spectrophotometer. The inhibition behavior of Ca-Na 2 MoO 4 -HNTs for Q235 steel in 3.5% NaCl solution was investigated by electrochemical impedance spectrum techniques. The results show that Ca-Na 2 MoO 4 -HNTs owns insoluble CaMoO 4 complex capping the end of HNTs, and the total loading capacity of Na 2 MoO 4 is about 14.6%. Moreover, the tunable release of Na 2 MoO 4 can be achieved by controlling the strength of the CaMoO 4 complex stoppers at the end of HNTs, and the release time of Na 2 MoO 4 can be prolonged to more than 600 min. Importantly, the release rate of Na 2 MoO 4 will increase sharply in acid solution, owing to the decomposition of CaMoO 4 complex. In addition, Q235 steel in 3.5% NaCl solution + 1.0 g/L Ca-Na 2 MoO 4 -HNTs exhibits higher inhibition efficiency (60.62% at 24 h) than Q235 steel in 3.5% NaCl solution. [ABSTRACT FROM AUTHOR]

Absorption is one of the most important methods for oil spill cleanup. An ideal absorbent is expected to possess advantages of low cost, green, high absorption capacity and excellent reusability. In this paper, a new kind of cellulose aerogel was successfully fabricated via cellulose oxidation, crosslinking, freeze drying and cold plasma modification. The obtained aerogel (water contact angle up to 152.8°) exhibited outstanding oil/water selectivity and high absorption capacity (13.77–28.20 g/g) for various oils and organic solvents. What's more, this kind of aerogel could be reused by simple compression. The absorption-desorption process could be repeated for at least 50 cycles. Through the kinetic analysis, it was found that the pseudo-second order model was more appropriate for the aerogel’s oil absorption process. Owing to its low cost, hydrophobicity, high absorption capacity and excellent reusability, this kind of aerogel is expected to be used in oils and organic solvents spill cleanup and oil/water separation field. [ABSTRACT FROM AUTHOR]

ZnAlCe layered double hydroxides intercalated with 1-hydroxyethylidene-1, 1-diphosphonic acid (HEDP) were synthesized by the co-precipitation method. The surface morphology and structure of ZnAlCe-HEDP LDHs were observed and determined by scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier transform infrared (FT-IR) spectroscopy. The inhibition behavior and mechanism of ZnAlCe-HEDP LDHs for Q235 steel in 3.5% NaCl solution was measured by weight loss, inductively coupled plasma mass spectrometer (ICP-MS), polarization curves, electrochemical impedance spectroscopy (EIS), energy dispersion spectrum (EDS) and X-ray photoelectron spectroscopy (XPS). The results show that the HEDP anion is successfully intercalated into ZnAlCe LDHs interlayer and the synthetic ZnAlCe-HEDP LDHs has a lamellar morphology with well-defined crystalline structure and a basal plane spacing 1.056nm. Compared with ZnAl-NO 3 LDHs and ZnAl-HEDP LDHs, ZnAlCe-HEDP LDHs has a better inhibition effect on Q235 steel in 3.5% NaCl solution. The higher inhibition effect of ZnAlCe-HEDP LDHs is related the reduction of chloride ions in solution by ion exchange effect between HEDP ions and chloride ions, and the formation of inhibition film on steel surface by the ferrous-HEDP chelates and zinc, aluminum and cerium hydroxides. [ABSTRACT FROM AUTHOR]

The chemical milling condition of 2219 aluminum alloy is investigated in the NaOH + Na 2 S + triethanolamine + Al 3+ alkaline system by the assistance of electric currents. The purpose is to study the influences of electric current densities on both the milling rate and the surface roughness of 2219 alloy under different temperatures, NaOH concentrations and additions of inhibitors. The experiments are carried out under the given requirement that the milling rate is from 0.08 mm/min to 0.14 mm/min and the surface roughness is less than 0.65 μm. The reaction temperature of the chemical milling process can be reduced by 10 °C with the application of current densities in the range of 0–20 mA/cm 2 . The concentration of NaOH in the alkaline system can be reduced from 180 g/L to 120 g/L with the application of current densities in the range of 0–60 mA/cm 2 . With the addition of Na 2 SiO 3 , Na 2 CO 3 and Na 2 SnO 3 inhibitors in the alkaline system, both the milling rate and the surface roughness of 2219 alloy decrease. The region enclosed with the suitable NaOH concentration and current density expands and moves towards the high current density. [ABSTRACT FROM AUTHOR]

Calcium alginate gel beads loaded with benzotriazole (defined as ‘benzotriazole-calcium alginate gel beads’) were successfully prepared by a piercing-solidifying method. Moreover, the insoluble Cu-benzotriazole complexes were introduced on the surface of these gel beads through the interaction between benzotriazole and Cu 2 + to obtain Cu-benzoltriazole-calcium alginate gel beads, which act as the barrier to extend benzotriazole release time. The loading amount of benzotriazole in the Cu-benzoltriazole-calcium alginate gel beads was determined by thermo-gravimetric analysis (TGA) and the releasing process of benzotriazole was traced by UV–vis spectrophotometer. The inhibition behavior of Cu-benzoltriazole-calcium alginate gel beads for Q235 steel in 3.5% NaCl solution was investigated by polarization and electrochemical impedance spectrum techniques. The results show that complete release time of benzotriazole from benzoltriazole-calcium alginate gel beads is about 400 min, and further prolonged to dozens of hours by forming a barrier of insoluble Cu-benzotriazole complexes. In addition, Q235 steel in 3.5% NaCl solution + 5.0 g/L Cu-benzoltriazole-calcium alginate gel beads exhibit the lower corrosion current density and higher inhibition efficiency (87.06% at 24 h) than Q235 steel in 3.5% NaCl solution. [ABSTRACT FROM AUTHOR]

The image printed by laser printer may be nonlinearly distorted by dot gain and dot loss. In this case, printer model is usually built to suppress this nonlinear distortion and to make sure the printout result is the same as input image. The parameters of the printer model which will directly affect the printout result are key. In this paper, the chroma or density values of printout result is changed into Munsell value, and optimal parameters of printer model are calculated via the calculation of minimal error between Munsell value and input gray value. And then the minimal-Munsell-value-error-based laser printer model (MMVEBLPM) is established and applied in the green noise halftone method. Experimental results showed that the optimal parameters can be calculated fast and the nonlinear distortion of laser printer is suppressed significantly with the proposed model. [ABSTRACT FROM AUTHOR]

The uniform porous structure makes activated porous carbons (APCs) superior electrode material. Traditionally, APCs are produced by a combination of time-consuming high-temperature heat treatment and activation, with a production time of up to several hours. The produced APCs have relatively low specific surface area (SSA) and porosity. Therefore, the electrochemical performance is poor, which limits its application in high-power energy storage devices. Here, APCs materials are directly synthesized by a high temperature shock (HTS) strategy using needle coke as a precursor. The structure of as-prepared APC is characterized by XRD, SEM and Raman, and electrochemical tests confirmed its good electrochemical performance. In the two-electrode system, the supercapacitor with HTS-APC as the electrode material provides a high energy density of 35 ​Wh kg−1 and a high power density of 875 ​W ​kg−1 in EMIMBF 4 ionic liquid. This work is instructive for the rapid synthesis of electrode materials, and also provides guidance for the large-scale application of porous carbon materials. [ABSTRACT FROM AUTHOR]

Hydroxyapatite (HA) bioactive film is a standard surface modification method for biodegradable Mg alloys. However, the corrosion resistance of HA film prepared before was mediocre, and the preparation process was complicated. In this study, hydroxyapatite film was prepared for the first time on layered double hydroxides (LDHs) coated Mg alloy by hydrothermal method. The structure and composition of LDHs and HA films were analyzed by scanning electron microscopy (SEM), X-ray diffraction (XRD), energy dispersive spectrometer (EDS), Fourier transform infrared (FT-IR) spectroscopy and X-ray photoelectron spectroscopy (XPS). The corrosion resistance and immersion behavior of the films in simulated body fluid (SBF) were investigated by using potentiodynamic polarization curve, electrochemical impedance spectroscopy (EIS) techniques. The effects of different pH and calcium to phosphorus molar ratios (Ca/P ratios) of HA hydrothermal solution were investigated. The experimental results show that HA films appear in petal-like, filamentous and flower-like. The corrosion resistance of the film first increases and then decreases with the pH from weak acid to alkaline. With the increase of the Ca/P ratio, the film is gradually denser, and the protective effect is enhanced. The immersion test results show that after 7 days of immersion, the impedance modulus of the composite film is about 5 × 103 Ω·cm2, which is ten times higher than the single LDHs film. The effects of the pH and Ca/P ratio of the HA hydrothermal solution on the preparation of HA film are simply explained by thermodynamic theory. The Mg-LDHs-HA composite film provide a corrosion protection barrier for Mg substrate and HA film is biologically active. The barrier effect and the mineralization behavior provide a better corrosion protection for Mg substrate. [Display omitted] • HA film was prepared for the first time on LDHs-coated Mg alloy. • The preparation method of the composite film is simple. • Mg-LDHs-HA composite film exhibits durable corrosion resistance in SBF solution. • The effects of pH and Ca/P ratio were explained using thermodynamic theory. [ABSTRACT FROM AUTHOR]

ZnO@ZIF-8 films were prepared on Q235 steel surface through solvothermal reaction by pre-electrodepositing ZnO films and modified with stearic acid (SA). The surface morphology, elements content, crystal structure and chemical structure of films were studied by scanning electron microscopy (SEM), energy dispersive spectrometer (EDS), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The wettability of films was measured by water contact angle meter. The corrosion behavior of films was tested by Electrochemical tests. ZnO films show hexagonal nanotubular morphology, having the best compactness and corrosion resistance at deposition current density of 2.3 mA/cm2 with the protection efficiency of 90.11%. After solvothermal reaction, ZIF-8 grains are formed and clad ZnO nanotubes, forming a contact film to prevent corrosive ions attacking steel efficiently. ZnO@ZIF-8 films have the best compactness and corrosion resistance at Zn2+ concentration of 0.06 mol/L with the protection efficiency of 99.83%. But the corrosion resistance of ZnO@ZIF-8 film declines quickly for the water molecules can get inside the film and destroy the bond between ZIF-8 grains. Thus, SA was grafted to ZnO@ZIF-8 film to enhance its hydrophobicity. After SA modification, the protection efficiency reaches 99.99% and maintains at 95.29% after 14 days immersion in the solution of 3.5 wt.% NaCl. [Display omitted] [ABSTRACT FROM AUTHOR]

The effect of temperature on corrosion process of 304 stainless steel (SS) in high temperature water was investigated by electrochemical noise (EN), scanning electron microscope (SEM), Raman spectrum and X-ray photoelectron spectroscopy (XPS). The experimental results showed that the corrosion process could be divided into two stages (passivity and active dissolution) with the increasing temperature. At 100 °C, the oxide film was a single layer mainly consisting of Cr 2 O 3 . However, at 250 °C, it became a double layer with an inner layer of Cr–Fe spinel compound and an out precipitated layer. The related growth mechanisms of the oxide film were also discussed. [ABSTRACT FROM AUTHOR]