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The microstructure, electrochemical corrosion behaviour and microhardness of Fe1.5CoNiCrCux (x = 0.5, 1.0, 1.5 and 2.0) high-entropy alloys (HEAs) were investigated by X-ray diffraction (XRD), scanning electron microscopy and an electrochemical workstation. The XRD spectra of Fe1.5CoNiCrCux HEAs confirmed the face-centred cubic solid solution structure and that all specimens consisted of an fcc matrix and a Cu-rich fcc phase. The results of electrochemical corrosion tests showed that Fe1.5CoNiCrCu0.5 HEAs exhibited low corrosion rates owing to their high corrosion potential and low corrosion current density. The major types of corrosion for Fe1.5CoNiCrCux HEAs belong to localised corrosion and pitting, which is attributed to Cu-rich and Cr-depleted phases in the interdendritic region. The microhardness of Fe1.5CoNiCrCux HEAs increases from 142 HV for alloys with x = 0.5 to 190 HV for alloys with x = 2.0.

The salt corrosion environment has direct degradation to durability of asphalt mixture and dynamic water also has an important influence on asphalt pavement performance. In order to evaluate the performance of asphalt mixture exposed to dynamic water and chlorine salt erosion, the asphalt mixture dynamic water-salt erosion apparatus was self-designed and the test parameters were reasonably set for the accelerated simulation of chlorine salt-water-temperature-load coupling action to asphalt mixture under real working conditions. Splitting test (25 °C and −10 °C) was adopted for assessing the performance of asphalt mixture suffered from chlorine salt-water-temperature-load coupling action. Then the grey entropy method was applied to analyze the significance of influencing factors on the performance of asphalt mixture such as dynamic water scouring times, temperature, salt solution concentration. Then the mechanism of performance deterioration of asphalt mixture was explored to some extent. The results show that the process of chlorine salt erosion and deterioration to asphalt mixture is accelerated by dynamic water and is closely related to the concentration and temperature of salt solution. Scouring times is the most significant factor influencing the performance of asphalt mixture exposed to dynamic water and chlorine salt erosion. The crystallization erosion caused by salt solution infiltrating into the voids and cracks of asphalt mixture is an important inducement for the performance deterioration.

Bismuth (Bi) has been known as a highly efficient electrocatalyst for CO2 reduction reaction. Stable free-standing two-dimensional Bi monolayer (Bismuthene) structures have been predicted theoretically, but never realized experimentally. Here, we show the first simple large-scale synthesis of free-standing Bismuthene, to our knowledge, and demonstrate its high electrocatalytic efficiency for formate (HCOO−) formation from CO2 reduction reaction. The catalytic performance is evident by the high Faradaic efficiency (99% at −580 mV vs. Reversible Hydrogen Electrode (RHE)), small onset overpotential (, Stable free-standing two-dimensional Bi monolayer (Bismuthene) structures have been predicted theoretically, but never realized experimentally. Here, the authors show a large-scale synthesis of free-standing Bismuthene and its electrocatalytic activity for CO2 reduction to formate.

In order to effectively solve the traffic safety problem caused by snow and ice covering the pavement in winter, steel wool fibers with different length and content were adopted in asphalt mixture to investigate its deicing performance. The deicing principle of steel wool fiber asphalt mixture by induction heating was expounded. Effects of different ice thicknesses, output currents, and ambient temperatures for asphalt mixture deicing performance were studied using an indoor-simulated induction heating deicing test. The deicing mechanism of steel wool fiber asphalt mixture by induction heating was analyzed. Grey relation entropy analysis between the average melting ice rate and the influencing factors was determined. The results show that the average ice melting rate of the asphalt mixture increases with the increase in steel wool fiber length and content. The steel wool fiber asphalt mixture heated by electromagnetic induction obtains satisfactory result. The average melting ice rate of asphalt mixture containing 6% steel wool fiber with a length of 3 mm can reach 0.50°C·s−1 at an ambient temperature of −5°C. The thinner the ice and the higher the ambient temperature, the higher the average melting ice rate. The output current is positively correlated with the average melting ice rate. The degree of influence of the five influence factors on the average melting ice rate is ranked in order as follows: fiber content, fiber length, output current, ambient temperature, and ice layer thickness.

The electrochemical reduction reaction of carbon dioxide (CO2RR) to carbon monoxide (CO) is the basis for the further synthesis of more complex carbon-based fuels or attractive feedstock. Single-atom catalysts have unique electronic and geometric structures with respect to their bulk counterparts, thus exhibiting unexpected catalytic activities. A nitrogen-anchored Zn single-atom catalyst is presented for CO formation from CO2RR with high catalytic activity (onset overpotential down to 24 mV), high selectivity (Faradaic efficiency for CO (FECO ) up to 95 % at -0.43 V), remarkable durability (>75 h without decay of FECO ), and large turnover frequency (TOF, up to 9969 h-1 ). Further experimental and DFT results indicate that the four-nitrogen-anchored Zn single atom (Zn-N4 ) is the main active site for CO2RR with low free energy barrier for the formation of *COOH as the rate-limiting step.

The performance of an asphalt mixture will deteriorate under the condition of salt erosion, but there are different opinions on the mechanism of deterioration. Few studies have focused on the relation between the change of void characteristics and performance deterioration of an asphalt mixture exposed to salt erosion. To explore the relation between the air voids characteristics of an asphalt mixture and mechanical damage under salt erosion, the mechanical damage in an asphalt mixture was measured by splitting strength. The asphalt mixture specimens, immersion solutions, asphalt mortar, and aggregate were scanned with CT technology. To segment the voids, the Otsu method was used over asphalt mortar and solution range of CT values. A three-dimensional reconstruction of the CT image was performed with Mimics 20 software to calculate the asphalt mixture&rsquo, s void characteristics. On this basis, the relationships between the change in void characteristics and splitting strength were analyzed. The results showed that the ideal calculated void fraction can be obtained by threshold segmentation of the image void/asphalt mortar interface with the local CT value Otsu method. Under the salt corrosion environment, the increase of open voids of an asphalt mixture is linearly correlated with the decrease of splitting strength, while salts&rsquo, crystallization in the open voids produces crystallization pressure, accelerating the volume growth of open voids. The early damage of an asphalt mixture suffered from the salt may be mainly physical damage. These results can provide a useful reference for the performance of damage research on asphalt mixtures in salt enrichment areas.

Differential scanning calorimetry (DSC) was used to investigate the thermal behavior and non-isothermal crystallization kinetics of the Fe67Nb5B28 metallic glasses prepared by melt-spinning method. DSC traces exhibit that the crystallization takes place through a single exothermic reaction, and it processes a good thermal stability in thermodynamics. The activation energies for nucleation and grain growth processes were calculated to be 536 ± 22 and 559 ± 20 kJ mol−1 by Kissinger equation, respectively, and 551 ± 24 and 574 ± 20 kJ mol−1 by Ozawa equation, respectively. It means that the grain growth process is more difficult than the nucleation process. The variation of local Avrami exponent n(x) with crystallized fraction x demonstrates that the crystallization mechanism varies at different stages. The n(x) is larger than 2.5 at the initial stage of 0

Sulfate erosion is a threat to durability and sustainability of pavement structure. In this work, the performance degradation of asphalt binder under internal sulfate erosion was investigated. Different dosages of Na2SO4 (0 wt.%, 2.5 wt.%, 5 wt.%, and 10 wt.%) samples were prepared to investigate the effect of sulfate on the performance of the asphalt binder. The surface tension test and low-temperature rheological property test were carried out to evaluate the adhesion of sulfate-incorporated asphalt mastic. Rapid freezing and thawing test with different concentrations of sulfate solution was conducted to explore the effect of sulfate concentrations and freeze-thaw cycles on the softening point and force ductility of matrix asphalt. Phases of the asphalt binder were characterized by Fourier transform infrared (FTIR) spectroscopy. The results show that sulfate has a negative impact on the road performance of the asphalt binder. Internal sulfate erosion decreased the adhesion of the asphalt binder. Also, the low-temperature rheological property of asphalt binder was deteriorated. After the freeze-thaw cycles of external sulfate erosion, softening point and tensile force peak of matrix asphalt increased and the low-temperature ductility decreased. The main reason of performance deterioration of the asphalt binder is the “salt aging” effect causing by sulfate erosion. The research results can provide useful reference for the durability design of asphalt mixture in sulfate-enriched regions.

In order to ensure the safety of traffic, asphalt pavement is commonly required to utilize aggregates with excellent anti-abrasion property. This results in the lack of high-quality aggregates. The incorporation of solid waste in the aggregates is regarded as a high potential alternative for solving this problem. Since its material properties, such as rough surface, high Polished Stone Value (PSV) and the excellent adhesion property of asphalt, Basic Oxygen Furnace (BOF) slag can effectively improve the skid resistance of asphalt mixtures. First, the material properties of BOF slag are reviewed in this study. Then, the skid resistance of asphalt mixtures and aggregates are commendably evaluated by the Polished Stone Value test, Wehner/Schulze Tester, Aachen Polishing Machine, British Pendulum Test and Sand Patch test. The physical and mechanical properties of BOF slag play a key role in asphalt mixtures. This review found that the skid resistance mechanism of the BOF slag asphalt mixture is governed by factors such as BOF slag properties, incorporation methods and gradation types. Finally, the economic and environmental benefits of BOF slag asphalt mixtures were discussed. In addition, the function of gas catalysis and the melting of ice and snow can be added to the BOF slag asphalt mixture for a cleaner development in engineering. Furthermore, the existing problems, research directions and corresponding measures in this field are directed towards more durable and functional asphalt pavement construction.

The application of top-grade calcined bauxite to improve the skid resistance of pavement surface coatings increases construction costs and causes excessive tire wear. Therefore, it is necessary to investigate the polishing behavior of different grades of calcined bauxite aggregate. The polished stone value of calcined bauxite was measured after the standard polishing time and the extended polishing time. The Los Angeles (L.A.) abrasion and the crushing value, profile roughness, hardness, X-ray diffraction, and micromorphology were also tested. The results showed that the calcined bauxite above 75# (the ratio of corundum to mullite by weight, C/M &gt, 1) satisfied the requirement of the ultra-thin friction course. Compared with basalt, the calcined bauxite above 80# (C/M &gt, 3) has better long-term skid resistance, even though the pavement surface is subject to heavier traffic. Due to the higher cohesion of lower porosity, more hard minerals to keep the surface roughness, and less soft minerals to smooth the surface roughness, calcined bauxite with a higher corundum content has the better skid resistance. There is a power law relationship between C/M and Polished Stone Value (PSV). Considering the diminishing returns of higher-grade calcined bauxite, it is necessary to accurately select the appropriate C/M of calcined bauxite before use in pavement surface coatings.

With the discovery of mechanically exfoliated graphene in 2004, two-dimensional (2D) nanomaterials have emerged as one of the most promising candidates in the fields of chemistry, material science, physics, and nanotechnology due to their unique physical, chemical, optical and electronic properties. In this Review, we briefly introduce the general synthetic strategies applied to 2D nanomaterials, followed by describing some important and newly developed members of the 2D family. Then, we discuss in detail the engineering strategies to enhance their intrinsic performance for extensive applications among the electrocatalysis, photocatalysis, energy storage, and bioimaging. Finally, the challenges and outlooks in these fields are also addressed.

To evaluate the feasibility of using activated coal gangue (ACG) as replacement of mineral filler in asphalt mixture, some properties of asphalt mastic containing ACG were investigated in this paper, compared with the traditional limestone mineral filler (LMF). The investigated mastic consisted of asphalt and filler at a mass ratio of 1:1. Cone penetration test (CPT), Dynamic Shear Rheometer test (DSR), Brookfield viscosity test (BVT) and Dynamic Mechanical Thermal Analysis (DMTA) were applied to research the shear resistance rheological property, rutting resistance, high-temperature viscosity characteristics and low-temperature property of asphalt mastic. With the application of scanning electron microscope (SEM) and Infrared Spectroscopy (IR), the mechanism of ACG imposed on asphalt mastic was analyzed. Results indicate the possibility of ACG as inorganic filler derived from solid waste to improve the performance of asphalt. The ACG has better effect on improving the shear strength and temperature sensitivity of asphalt mastic than LMF. Besides, ACG has positive effect on high-temperature properties while some negative effect on low-temperature properties of asphalt mastic. The results also indicate that the physical adsorption between the ACG filler and asphalt binder is the main mode of action.

The soft magnetic properties of Fe-based nanocrystalline alloys are determined by their grain size. In the present article, the (Fe0.4Co0.6)79Nb3B18 nanocrystalline alloys have been successfully prepared by isothermal annealing. The variation of soft magnetic properties as a function of annealing temperature and incubation time is investigated in detail. Two distinct crystallization behaviors were found for the (Fe0.4Co0.6)79Nb3B18 alloys. The initial nanocrystallization products comprise a mixture of &alpha, Fe(Co), Fe2B, and Fe23B6-type crystalline metastable phases, and the final crystallization products are composed of &alpha, Fe(Co), Fe2B, and Fe3B crystalline phases. The grain size decreases first and then increases with the increasing annealing temperature in the range of 764&ndash, 1151 K, and a fine grain size with mean grain size of 12.7 nm can be achieved for alloys annealed at 880 K. As the annealing temperature increases from 764 K to 1151 K, the saturation magnetization increases first and then decreases without a significant increase of the coercivity. The alloys annealed at 880 K exhibit the optimized soft magnetic properties with high Ms of 145 emu g&minus, 1 and low Hc of 0.04 Oe.

Tight reservoirs normally have production problems due to very low matrix permeability and different damage mechanisms during drilling, completion and stimulation operations. These reservoirs have small pore throat size with significant capillary pressure energy suction that imbibes and holds liquid in the capillary pores. Such residues from Guar after gel breaks cause formation damage and low conductivity, and it can significantly reduce well productivity even in tight gas reservoirs. This paper presents a new cellulose derivative of instant dissolution and free of residue. The field test results of the new fluid in tight gas reservoirs in China show importance of minimizing formation damage in a hydraulic fracturing stimulation. Otherwise, the well productivity improvement may not be achieved in the case of excessive residues into formation during hydraulic fracturing operations. A new fluid has been applied in 18 wells in western China and the results show that the new fluid was easy to prepare and rapidly dissolved with no "fish eye", this system can reach 97% of the peak viscosity within 2 minutes, and the surface tension of the gel breaking liquid is 18.44 mN/m. No residue was found after the gel was broken, its conductivity was improved, and the formation damage is less than 13% in the core test. Meanwhile it has excellent properties of proppant suspension. Gas production in multiple wells of the tight gas reservoir increased to 2.13×105 m3/d after stimulation with the new fluid, 4.2 times higher than similar groups of wells using Guar-based fracturing fluids.