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The surface texture of asphalt pavement has a significant effect on skid resistance performance. However, its contribution to the performance of skid resistance is non‐homogeneous and subjects to local validity. There are also a few deep learning models that take into account the effective contact texture region. This paper proposes a convolutional neural network model based on the effective contact texture region, containing macro‐ and micro‐scale awareness sub‐modules. In this study, the asphalt mixture with varying gradations was designed to accurately obtain the effective contact texture region. Then, the textures were disentangled into macro‐ and micro‐texture scales by applying the fast Fourier transform and fed into the model for training. Finally, the area of effective contact texture region was calculated, and the effective contact ratio parameter was then proposed using the triangulation algorithm. The results showed that the effective contact texture area of pavement varies by the asphalt mixture type. The effective contact ratio parameter exhibited a significant positive correlation (Pearson correlation coefficient is 0.901, R2= 0.8129) with skid resistance performance and was also influenced by key sieve aggregate content from 2.36 to 4.75 mm. The data of effective contact texture region following disentanglement significantly released the model performance (the relative error dropped to 1.81%). The model exhibited improved precision and performance, which can be utilized as an efficient, non‐contact alternative method for skid resistance analysis. [ABSTRACT FROM AUTHOR]

To reduce vehicle exhaust gas pollution in transport-intensive roadways and tunnels, six types of photocatalytic asphalt binders were designed using graphite-phase carbon nitride (g-C3N4) and nanoscale titanium dioxide (nano-TiO2) particles. In this paper, the rheological behaviors and fatigue life of the nano-TiO2-modified asphalt binder (TiO2-MA) and g-C3N4-modified asphalt binder (C3N4-MA) were investigated. NO degradation capacity of six types of photocatalytic asphalt binders was characterized under visible light conditions. The results showed that TiO2-MA had more excellent rheological behaviors and rutting resistance than C3N4-MA. In addition, 4 wt% nano-TiO2 markedly improved the rheological behaviors and rutting resistance of MA compared to other dosages. TiO2-MA exhibited higher fatigue resistance. The fatigue life of TiO2-MA with 4 wt% nano-TiO2 was increased to 234.1% at 2.5% strain and 242.5% at 5% strain, respectively, compared to base asphalt binder (BA). C3N4-MA had better NO degradation capacity than TiO2-MA. Meanwhile, the NO degradation efficiency of C3N4-MA reached 17.8% with 5 wt% g-C3N4. [ABSTRACT FROM AUTHOR]

Near the coast of China, a large amount of sediment is produced during construction work. In order to mitigate the environmental damage caused by sediment and enhance the performance of rubber-modified asphalt effectively, solidified silt material and waste rubber were prepared to modify asphalt, and its macroscopic properties, such as viscosity and chemical composition, were determined via a routine physical test, DSR, Fourier Transform Infrared Spectroscopy (FTIR), and Fluorescence Microscopy (FM). The results show that, with the increase in powder particles and the addition of a certain amount of hardened mud, the mixing and compaction temperature of modified asphalt can be significantly increased—still reaching the design standard. In addition, the high thermal stability and fatigue resistance of the modified asphalt were clearly better than those of the ordinary asphalt. From the FTIR analysis, rubber particles and hardened silt only exhibited mechanical agitation with the asphalt. Considering that excessive silt might result in the aggregation of matrix asphalt, the addition of an appropriate amount of hardened solidified silt material can eliminate the aggregation. Therefore, the performance of modified asphalt was optimum when solidified silt was added. Our research can provide an effective theoretical basis and reference values for the practical application of compound-modified asphalt. Therefore, 6%HCS(6:4)-CRMA have better performance. Compared to ordinary rubber-modified asphalt, the composite-modified asphalt binder has better physical properties and a more suitable construction temperature. The composite-modified asphalt uses discarded rubber and silt as raw materials, which can effectively protect the environment. Meanwhile, the modified asphalt has excellent rheological properties and fatigue resistance. [ABSTRACT FROM AUTHOR]

Reports have pointed out that nearly 50% of the global total energy demand for buildings is used for daily heating and cooling. Therefore, it is very important to develop various high-performance thermal management techniques with low energy consumption. In this work, we present an intelligent shape memory polymers (SMPs)-based device with programmable anisotropic thermal conductivity fabricated by a 4D printing technique to assist in thermal management with net zero energy. Highly thermal conductive BN nanosheets were textured in a poly (lactic acid) (PLA) matrix by 3D printing, and the printed composites lamina exhibited significant anisotropic thermal conductivity. The direction of heat flow in devices could be switched programmably, accompanying the light-activated deformation controlled by grayscale of composite, which was demonstrated by the "windows" arrays composed of in-plate thermal conductivity facets and SMPs-based hinge joints, achieving the programmable movement of opening and closing under different light conditions. Based on solar radiation-dependent SMPs coupled with the adjustment of heat flow along anisotropic thermal conductivity, the 4D printed device has been proved in concept for potential applications in thermal management in a building envelop for dynamic climate adaptation, taking place automatically based on the environment. [ABSTRACT FROM AUTHOR]

Na0.5Bi0.5TiO3 (NBT)-based ceramics are promising lead-free candidates for energy-storage applications due to their outstanding dielectric and ferroelectric properties derived from large polarization. However, the high coercive field and large remnant polarization are unfavorable for practical applications, and thus NBT-based ceramics with relaxation behavior via doping/forming solid solutions with other elements/components have been widely studied. In this work, BaTiO3 (BT) was introduced to the 0.94Na0.5Bi0.5TiO3-0.06Bi(Mg2/3Nb1/3)O3 system by a conventional solid-state reaction to form a homogeneous solid solution of 0.94[(1−x)Na0.5Bi0.51TiO3-xBaTiO3]-0.06Bi(Mg2/3Nb1/3)O3 (BNT-100xBT-BMN). As the BT content increased, the proportion of the rhombohedral R3c phase increased while that of the tetragonal P4bm phase decreased, leading to the maximum Pmax (38.29 μC/cm2) and Eb (80 kV/cm) obtained in BNT-7BT-BMN (x = 0.07) composition. Specifically, the optimal energy storage properties of Wrec ~ 1.02 J/cm3 and η ~ 62.91% under 80 kV/cm were obtained in BNT-7BT-BMN ceramics, along with good temperature stability up to 200 °C, which are promising factors for future pulse power applications. [ABSTRACT FROM AUTHOR]

The recombination of charge carriers in photocatalysts is one of the main factors restricting photocatalytic performance. In this paper, the NaNbO3/g-C3N4 heterojunction photocatalyst was prepared by a simple ultrasonic mixing approach and applied to obtain superior piezo-photocatalytic activity. The results showed that the NaNbO3 nanowires were attached to the g-C3N4 surface for efficient degradation of rhodamine B (RhB). Through the synergistic action of visible-light irradiation and ultrasonic vibration, the RhB solution could be degraded within 30 min by 5% NaNbO3/g-C3N4 heterojunction. The reaction rate constant (k) of 5% NaNbO3/g-C3N4 heterojunction is 2.7 times that of pure g-C3N4. Moreover, quenching tests and electronic spin resonance (ESR) indicated that ·O2− was the primary active species for RhB degradation. The enhanced photocatalytic performance was attributed to the formation of the heterojunction at the NaNbO3/g-C3N4 interface. Furthermore, the piezoelectric field that originated from the bending deformation of NaNbO3 nanowires effectively promoted charge carriers separation efficiency in the NaNbO3/g-C3N4 heterojunction. [ABSTRACT FROM AUTHOR]

With the ever-increasing demand for energy, research on energy storage materials is imperative. Thereinto, dielectric materials are regarded as one of the potential candidates for application in advanced pulsed capacitors by reason of their ultrahigh energy-storage density, low energy loss, and good thermal stability. Among the numerous dielectric materials for energy storage, sodium bismuth titanate (Bi0.5Na0.5TiO3, BNT) with high saturation polarization, as one of the successful alternatives to lead-based materials, has been extensively studied. However, degraded dielectric and ferroelectric properties as a consequence of chemical alterations usually produced by inhomogeneity in microstructure and composition due to the ion volatilization during preparing, thus affecting performance of devices. Hence, this review served to encompass the current state and progress on the optimization of energy storage performance in lead-free BNT-based materials over the past few years, including ceramics, multilayer ceramics, thin films, and thick films, involved in solid solution modification, metal/metallic oxide doping, process optimization and other related aspects to optimize energy storage performance. Furthermore, some prospective approach in the improvement of energy storage performance for BNT-based materials were also provided in this work according to the existing theoretical and experimental results, to impel their practical application. [ABSTRACT FROM AUTHOR]

Cracking risk of cementitious materials remains one of the serious problems in the construction and highway field. Here, a series of pH-sensitive microgels with different anionic content and crosslinking density have been successfully synthesized and applied in cement mortar. The absorption behavior and pH sensitivity of microgel in aqueous solutions were determined. The effects of microgel on hydration degree, autogenous shrinkage, and compressive strength of cement mortar were studied. Experimental results indicate that the microgel exhibits less desorption in the pore solution and releases water timely in pH from 12–13. Despite the different anionic content of microgels, the addition of microgel with moderate crosslinking density is 0.19%∼0.31% , which can alleviate the autogenous shrinkage of cement mortar. The compressive strength of mortar can be increased by about 5.7 MPa by the microgels with low anionic content and moderate crosslinking density, thereby showing excellent internal curing effect. [ABSTRACT FROM AUTHOR]

Waterborne epoxy-resin-emulsified asphalt (WEREA) has excellent adhesion and can be used as a good waterproofing tack coat; however, there are some problems such as the poor compatibility between the waterborne epoxy and the emulsified asphalt, and the brittleness of the cured material. In the present work, oxidized furfural extract oil was used as a compatibilizer to prepare the waterborne epoxy emulsion and waterborne epoxy-resin-emulsified asphalt, and their modification effects were studied. The extraction oil was oxidized with potassium permanganate. The effects of oxidized extraction oil on the waterborne epoxy-resin-emulsified asphalt performance were investigated through experiments on viscosity, mechanical properties, and aging resistance. Combined with infrared spectroscopy and fluorescence microscopy, the compatibility and microstructure of the oxidized extraction oil modified WEREA were observed and analyzed. The result showed that the carboxyl group was introduced into the chemical structure of the extraction oil after oxidation. Oxidized extraction oil (OEO) and waterborne epoxy resin (WER) had good compatibility. When the content of OEO in the WER is 21%, the elongation at break of the WER can reach up to a maximum of 91.5%, and has a significant increase of 33.2%. OEO can significantly improve the elongation at the break and aging resistance of WEREA, especially when the mix ratio of oxidized extraction oil and epoxy resin was 6:5, when the breaking elongation of WEREA can be increased by 69%, and the compatibility between the epoxy resin and emulsified asphalt was the best. Moreover, the loss in elongation at the break of aged WEREA decreased from 13.7% to 4.9%. [ABSTRACT FROM AUTHOR]

In order to improve the initial color and the long-term heat stability of super-transparent polyvinyl chloride (PVC), a series of composite heat stabilizers consisting of unsaturated Zn oleate and uracil derivatives have been designed in this paper. The uracil derivatives are 1,3-dimethyl-6-amino-uracil (DAU) and 6,6′-diamino-1,1′,3,3′-tetramethyl-5,5′-(ethylidene)bisuracil (OSU). The static thermal stability, dynamic thermal stability, and transparency were used to evaluate the properties of the stabilized transparent PVC sheets. The results indicate that the compatibility between the stabilizer and PVC was greatly enhanced by introducing an unsaturated long-chain Zn oleate and a long alkyl chain bisuracil derivative. Through the thermal discoloration test, the best ratio of DAU/zinc oleate (DAU/Zn) and OSU/zinc oleate (OSU/Zn) was determined to be 4:1, with a total amount of 3 phr in 100 phr PVC. It was verified that the combination of zinc oleate with uracil derivatives could improve the long-term thermal stability of PVC, and the DAU/Zn was better than that of the OSU/Zn. In addition, through the transmission/haze verification, adding a proper amount of epoxidized soybean oil (ESBO) and phosphite ester to the OSU/Zn system has a certain synergistic effect. The thermal stability and transparency of PVC can be remarkably enhanced. [ABSTRACT FROM AUTHOR]

There are few studies on denitrification related to the nitrogen cycle in Ebinur Lake wetland. This study aimed to explore the response of the diversity and composition of denitrifying bacteria to the environmental factors in wetland, so as to obtain more information about the community structure of denitrifying bacteria driven by environmental factors. Using the genes encoding nitrite reductase (nirS and nirK) as molecular markers, we analysed the seasonal changes in the diversity of denitrifying bacteria in halophyte soils by high-throughput sequencing technology. The results showed that the diversity of denitrifying bacteria was higher in July and lower in April, showing seasonal changes. The diversity index of denitrifying bacteria in rhizosphere soil was higher than that in non-rhizosphere soil. The diversity of denitrifying bacteria in the Phragmites australis rhizosphere soil was the highest. The diversity of nirK denitrifying bacteria was higher than that of nirS denitrifying bacteria, but the relative abundance was lower than that of nirS denitrifying bacteria. Three-way ANOVA showed that soil types, vegetation types and season had significant effects on the diversity of denitrifying bacteria. Furthermore, redundancy analysis indicated that nitrate was the environmental factor that significantly affected the community structure of nirS denitrifying bacteria in wetland, and electric conductivity, total nitrogen, ammonium and nitrate were the environmental factors that significantly affected the community structure of nirK denitrifying bacteria. These results provide data basis and theoretical support for the dynamic change of diversity of denitrifying bacteria in wetland. [ABSTRACT FROM AUTHOR]

Water pollution caused by dye wastewater is a potential threat to human health. Using photocatalysis technology to deal with dye wastewater has the advantages of strong purification and no secondary pollution, so it is greatly significant to look for new visible-light photocatalysts with high photocatalytic ability for dye wastewater degradation. Semiconductor photocatalyst silver phosphate (Ag3PO4) has high quantum efficiency and photocatalytic degradation activity. However, Ag3PO4 is prone to photoelectron corrosion and becomes unstable during photocatalysis, which severely limits its application in this field. In this study, a tubelike g-C3N4/Ag3PO4 heterojunction was constructed by the chemical precipitation method. An Ag3PO4 nanoparticle was loaded onto the surface of the tubelike g-C3N4, forming close contact. The photocatalytic activity of the photocatalyst was evaluated by the degradation of RhB under visible-light irradiation. The tubelike g-C3N4/Ag3PO4-5% heterojunction exhibited optimal photocatalytic performance. In an optimal process, the degradation rate of the RhB is 90% under visible-light irradiation for 40 min. The recycling experiment showed that there was no apparent decrease in the activity of tubelike g-C3N4/Ag3PO4-5% heterojunction after five consecutive runs. A possible Z-type mechanism is proposed to explain the high activity and stability of the heterojunction. [ABSTRACT FROM AUTHOR]

To maximize the utilization of red mud in geopolymers, a red mud–metakaolin (RM-MK) geopolymer and red mud–fly ash (RM-FA) geopolymer were prepared, respectively. The effects of red mud content on the compressive strength and microstructure of the geopolymers were investigated under three different curing conditions. The results showed that the strength of the geopolymer decreased linearly with an increase in the red mud content, whether curing at room temperature or 80 °C. Surprisingly, curing in an autoclave, the appropriate amount of red mud had a favorable impact on the mechanical properties of the geopolymers. When the amount of red mud was 50%, the strength of the RM-MK geopolymer reached its highest compressive strength, 36.3 MPa, and the strength of the RM-FA geopolymer reached its highest at 31.7 MPa. Compared with curing at low temperature, curing the red mud-based geopolymers under a higher temperature and higher pressure can maximize the use of red mud. XRD analysis indicated that zeolite minerals formed. The SEM results showed that the geopolymers cured in an autoclave had a dense structure. [ABSTRACT FROM AUTHOR]

Ba0.6Sr0.4TiO3 (BST) ceramic materials have been widely used in the field of multilayer ceramic capacitors. Surface modification through the surface coating to form a heterogeneous layer could effectively improve the dielectric properties. In this work, BST powders were prepared by a co-precipitation method. The effects of reaction conditions on the microstructure of the BST powder were investigated. The reaction temperatures significantly affected the morphology of BST powder, and the rhombic-type particles were obtained with the reaction temperature around 80 °C. Meanwhile, the BST@Fe2O3 was prepared by the chemical precipitation method using BST powders with rhombic-type microstructure as "core", and the so-called "core-shell" microstructure was confirmed in the BST@Fe2O3 powder. Then, BST@x wt%Fe2O3 (x = 2.5, 5, 7.5, and 10, denoting the different content of Fe2O3) ceramics were further prepared, and the influence of "core-shell" structure on the phase structure, microstructure, and dielectric properties was investigated. With the increasing of Fe2O3 content, the ferroelectric–paraelectric phase transition temperature shifts toward lower temperatures, and dielectric peaks gradually become broad and frequency-dependent, which may be due to inconsistent chemical composition from core to shell. [ABSTRACT FROM AUTHOR]

The utilization of processed waste materials in road construction is of utmost significance from the environmental and economic viewpoints. In this paper, waste cooking oil (WCO) and ground tire rubber (GTR) were applied to modify the asphalt binder. Based on the optimal content of both modifiers, sixteen asphalt samples with different combinations of the two wastes were designed. Relevant tests including basic properties along with rheological behavior and chemical characterization were carried out on the modified asphalt. The results indicated that the modified asphalt with 20 wt % GTR and 2.5 wt %-5 wt. % WCO exhibited satisfactory high temperature resistance and low temperature rheological properties. The Fourier transform infrared spectroscopic investigation revealed that the presence of GTR increased the concentration of styrene and butadiene while the addition of WCO introduced fatty acids and esters to modified asphalt. Overall, the road performance studies demonstrate that modified asphalt mixture with 5 wt % WCO and 20 wt % GTR displayed a markedly improved anti-rutting properties, water stability and superior low-temperature performance compared to normal asphalt mixture. • The molecular structures of WTO/GTR-modified asphalt were analyzed. • Asphalt modified with an appropriate amount of GTR and WCO exhibited optimum properties. • GTR increased the concentration of functional groups in modified asphalt binder. • WCO introduced fatty acids and esters to modified asphalt binder. • WTO/GTR-modified asphalt mixtures showed a promising application in road industry. [ABSTRACT FROM AUTHOR]