Interfaces play critical roles in electronic devices and provide great diversity of film morphology and device performance. We retrospect the substrate mediated vacuum film growth of benchmark high mobility material 2, 7-dioctyl[1]benzothieno[3,2-b]benzothiophene (C8-BTBT) and the interface electronic structures. The film growth of C8-BTBT molecules is diversified depending on the substrate-molecule and molecule-molecule interactions. On atomic smooth substrates C8-BTBT film grows in layer-by-layer mode while on coarse substrate it grows in islands mode. The initial molecular layer at dielectric, semiconductor and conductive substrates displays slight different lattice structure. The initial molecule orientation depends on the substrate and will gradually change to standing up configuration as in bulk phase. C8-BTBT behaves as electron donor when contacting with dielectric and stable conductive materials. This usually induces a dipole layer pointing to C8-BTBT and an upward bend bending in C8-BTBT side toward the interface. Although it is air stable, C8-BTBT is chemically reactive with some transition metals and compounds. The orientation change from lying down to standing up in the film usually leads to decrease of ionization potential. The article provides insights to the interface physical and chemical processes and suggestions for optimal design and fabrication of C8-BTBT based devices.

In this study, a high-purity In₂Ga₂ZnO₇ ceramic target was used to deposit indium gallium zinc oxide (IGZO) films by RF magnetron sputtering technology. The microstructure, growth state, optical and electrical properties of the IGZO films were studied. The results showed that the surface of the IGZO film was uniform and smooth at room temperature. As the substrate temperature increased, the surface roughness of the film gradually increased. From room temperature to 300 ° C, all the films maintained amorphous phase and good thermal stabilities. Moreover, the transmission in the visible region decreased from 91.93% to 91.08%, and the band gap slightly decreased from 3.79 to 3.76 eV. The characterization of the film via atomic force microscope (AFM) and X-ray photoelectron spectroscopy (XPS) demonstrated that the film prepared at room temperature exhibited the lowest surface roughness and the largest content of oxygen vacancies. With the rise in temperature, the non-homogeneous particle distribution, increase in the surface roughness, and reduction in the number of oxygen vacancies resulted in lower performance of the α-IGZO film. Comprehensive analysis showed that the best optical and electrical properties can be obtained by depositing IGZO films at room temperature, which indicates their potential applications in flexible substrates.

Magnetorheological (MR) materials are a class of smart material, whose the mechanical/rheological state can be controlled under a magnetic field. Magnetorheological materials are typically fluids, gels, or elastomers. In this study, anisotropic and isotropic magneto-rheological elastomer (MRE) samples were fabricated using a silicone rubber matrix with carbonyl iron particles as filler particles. The magnetic field-dependent inductance properties of these samples were studied using inductors specially designed for the analysis. The effect of the filler particle content, fabrication conditions, and inductance properties were characterized using a self-built system in both constant and transient magnetic fields. These factors show a significant effect on the inductance properties of the MRE inductor under an applied magnetic field. The anisotropic MRE inductor was more sensitive than the inductor based on an isotropic MRE. Owing to the presence of a constant magnetic field, the inductance value of the MRE inductor decreased with an increase in the external magnetic field. An attempt in elucidation of the mechanism is reported here. This study may enable the MRE to be widely used in practical applications such as monitoring magnetic field or detecting the filler particle content inside MR materials.

The electrical contact and mechanical performances of Ag-SnO₂ contact materials are often improved by additives, especially Cu and its oxides. To reveal the improvement mechanism of metal additive, the effects of Cu nanoparticles on the interface strength and failure behavior of the Ag-SnO₂ contact materials are investigated by numerical simulations and experiments. Three-dimensional representative volume element (RVE) models for the Ag-SnO₂ materials without and with Cu nanoparticles are established, and the cohesive zone model is used to simulate the interface debonding process. The results show that the stress—strain relationships and failure modes predicted by the simulation agree well with the experimental ones. The adhesion strengths of the Ag/SnO₂ and Ag/Cu interfaces are respectively predicted to be 100 and 450 MPa through the inverse method. It is found that the stress concentration around the SnO₂ phase is the primary reason for the interface debonding, which leads to the failure of Ag-SnO₂ contact material. The addition of Cu particles not only improves the interface strength, but also effectively suppresses the initiation and propagation of cracks. The results have an reference value for improving the processability of Ag based contact materials.

This study involves A356 alloy molded through ultrasonically vibrated cooling slope. The slope alongside ultrasonic power enables indispensable shear for engendering slurry from which the semisolid cast/heat treated billets got produced. An examination demonstrates ultrasonically vibrated cooling slope influencing the liquid fraction/microstructure/physical characteristics of stated billets. The investigation encompasses five diverse ultrasonic powers (0, 75, 150, 200, 250 W). The ultrasonic power of 150 W delivers finest/rounded microstructure with enhanced physical characteristics. Microstructural modifications reason physical transformations because of grain refinement and grain-boundary/Hall-Petch strengthening. A smaller grain size reasons a higher strength/shape factor and an increased homogeneity reasons a higher ductility. Microstructural characteristics get improved by reheating. It is owing to coalescence throughout temperature homogenization. The physical characteristics is improved by reheating because of a reduced porosity and enhanced dissolution besides augmented homogeneity. A direct comparison remains impossible owing to unavailability of researches on ultrasonically vibrated cooling slope.

A series of sweeping detonation experiments were conducted to study the grain boundary effects during the primary spallation of high-purity copper cylinder. The free surface velocity profile of the shocked samples was measured by Doppler pins systems. The soft-recovered samples were characterized by optical and electron backscatter diffraction microscopy, and the effects of microstructures like grain boundaries, and crystal orientation on spall behavior were investigated. The results indicated that the critical stress of deformation twinning in cylindrical copper increased. The nucleation sites of spallation damage were determined by the joint influence of the grain orientation (Taylor factor) and the angle between grain boundaries and radial impact-stress direction. Voids were prone to nucleating at the grain boundaries perpendicular to the radial impact-stress direction. Nevertheless, the number of voids nucleated at boundaries was relatively different from the results obtained from the plate impact experiment and plate sweeping detonation experiment, which is a result of the curvature that existed in the cylindrical copper and the obliquity of the impact-stress direction during sweeping detonation loading.

High density lanthanum hexaboride (LaB₆) polycrystalline with (100) preferred orientation was prepared by spark plasma sintering (SPS) using LaB₆ nanocubes as raw materials in this work. Microstructure and thermionic electron emission property of LaB₆ polycrystalline were investigated detailedly. The results show that the LaB₆ polycrystalline had a relative density of 95.8%, and there was a (100) preferred orientation on its surface normal to SPS pressing direction. The work function of LaB₆ polycrystalline normal surface was only 2.73 eV, which was almost close to the theoretical work function of LaB₆ (100) single crystal surface. The reasons for preferential orientation of LaB₆ polycrystalline were analyzed.

The hot rolling experiment of AZ31 magnesium alloy was carried out by laying anoverlay mold at the initial temperature of 400 °C. According to the Mizushima automatic plan view pattern control system (MAS) rolling theory and the cross rolling process, different reductions in the middle and edges of the magnesium alloy were realized, and the influence of the regional controlled reduction rolling on the edge cracks and microstructure gradient of the magnesium alloy were analyzed. It is shown that this rolling approach has reduced the maximum edge crack depth of the rolled piece by 56.85%, and there is a weakening tendency in the base surface texture of the strip edge, the base surface texture density drops from 23.97 to 17.48 after ordinary flat rolling. It exhibits basal texture gradients from the edge to the middle of the sheet along the RD direction, which reflected the uneven deformation of the sheets. It is suitable for the processing of metal molds that require large edge reductions such as mobile phone shells, and provided a theoretical basis for the variable thickness rolling of the magnesium alloy strip.

Unequal diameter twin-roll casting (UDTRC) can improve the formability, surface conditions, and production efficiency during the fabrication of clad strips. Using Fluent software, a numerical simulation is used to study the asymmetric heat transfer characteristics of Cu/Al clad strips fabricated by UDTRC. The effects of roller velocity ratio, Cu strip thickness, and inclination angle on the kissing point position, as well as the entire temperature distribution are obtained. The heat transfer model is established, and the mechanism is discussed. The Cu strip and rollers are found to be the main causes of asymmetric heat transfer, indicating that the roller velocity ratio changes the liquid zone proportion in the molten pool. The Cu strip thickness determines the heat absorption capacity and the variations in thermal resistance between the molten Al and the big roller. The inclination angle of the small roller changes the cooling time of big roller to molten Al. Moreover, the microstructure of Al cladding under different roller velocity ratios is examined. The results show significant grain refinement caused by the shear strain along the thickness direction of Al cladding and the intense heat transfer at the moment of contact between the metal Al cladding and Cu strip.

Fibrous activated alumina is widely applied in catalysts, adsorbents, and composite materials. This work presents a green approach in preparing the fibrous activated Al₂O₃ with high purity and specific surface area through multistep phase transformation of aluminum-bearing substances using intermediate dawsonite as a template. Thermodynamic calculations and experimental results show that increasing the concentration of Na₂CO₃ and (NH₄)₂CO₃ is remarkably beneficial to the formation of dawsonite and ammonium aluminum carbonate hydroxide, respectively. Based on determination of dissolution and precipitation mechanism, the ultrafine granular gibbsite is converted to the uniform fibrous dawsonite with a ratio of length to diameter over 50, and the fibrous dawsonite changes into the long fibrous ammonium aluminum carbonate hydroxide with a ratio of length to diameter is about 80 in above 70 g/L (NH₄)₂CO₃ solution. Furthermore, the activated alumina remains fibrous morphology after roasting ammonium aluminum carbonate hydroxide at a slow heating rate, plentiful open mesopore and weak aggregation of particles, which contributes to the high specific surface area of 159.37 m²/g at 1273 K for the activated alumina. The complete transformation of dawsonite to ammonium aluminum carbonate hydroxide and high specific surface area contribute to the purity of the activated fibrous alumina above 99.9% with low Na and Fe content.

The phase transition, morphology, stability and pulverization performance of dicalcium silicate (C₂S) with different Na₂O additions during the high-temperature sintering process were studied using XRD, SEM-EDS, FT-IR, and Raman spectra methods. When the CaO to SiO₂ molar ratio is 2.0 and the Na₂O to SiO₂ molar ratio is below 0.20, the crystalline calcium silicate compounds include γ-C₂S and β-C₂S. As the Na₂O addition increases, the proportion, crystallinity and grain size of β-C₂S in the sintered products increase, those parameters of β-C₂S decrease, and the content of amorphous phase increases. Na₂O mainly forms solid solutions in β-C₂S and inhibits the transition of β-C₂S to γ-C₂S, resulting in the sintered products unpulverized. The stability of sintered products in alkali solution decreases significantly with the increasing Na₂O additions, and the β-C₂S solid solution with Na₂O is less stable than γ-C₂S. The mechanism that Na₂O affects the transition of C₂S as well as its stability was also discussed, which can give actual guidance for the treatment of low-grade alumina-containing resources by the sintering process.

In this study, porous silica with high surface area was prepared through selective leaching of thermally activated chlorite in HCl solution. In the process, chlorite was activated by pre-calcining treatment, then activated components (MgO, Al₂O₃, and Fe₂O₃) were selectively leached by acid solution, resulting in the formation of nanopores in situ. The morphology, structure, surface area and pore-size distribution of the material were characterized by XRD, TG/DSC, ²⁷Al MAS NMR, SEM, TEM and N₂ adsorption-desorption isotherms. The highest specific surface area (S_BET=333 m²/g) was obtained by selectively leaching the 600 °C calcined chlorite from 3 mol/L HCl at 90 °C for 2 h. The pore sizes and specific surface areas can be controlled by calcination and leaching conditions. The ²⁷Al MAS NMR spectra of the samples revealed the relationship between structural transformation and the selective acid leaching properties of thermal-activated chlorite, demonstrating that Al^VI transfers into Al^V when chlorite changes into activated chlorite during thermal activation, and the coordinations of Al has a significant effect on acid solubility of chlorite. The as-prepared porous silica showed favorable adsorption abilities with capacity of 148.79 mg/g for methylene blue at pH of about 7 and temperature of 25 °C, indicating its promising potential in adsorption application.

Phosphate is widely used to immobilize cadmium (Cd) and lead (Pb) in soils through the insoluble metal phosphate precipitation. However, an increase in the phosphorus content of the environment can cause new pollution. In this study, five slow-release phosphate amendments (SRPAs) were synthesized and their characteristics including BET, SEM, FTIR, swelling ratio, and thephosphorus release were determined. The results show that SRPA was a sphere with a network structure with a specific surface area of 5 to 7.18 m²/g andcontained phosphate, hydroxyl, carboxyl and other functional groups. Among five SRPAs, S3 sample showed good performance for phosphate release. Phosphate release from SRPA was well fitted with Ritger-Peppas model with constant n between 0.45 and 0.85, indicating that the phosphate release was in accordance with non-Fickian diffusion. As compared with monocalcium phosphate (MCP), SRPA application led to a lower concentration of water-soluble phosphorus in the soil sample and higher remediation efficiencies of Cd and Pb. The remediation efficiencies of water-soluble Cd and Pb in soil with SRPA were 97.1% and 97.9%, respectively. The remediation efficiencies of bioavailable Cd and Pb were 71.85% and 76.47%, respectively. The results of Tessier extraction showed that the exchangeable and carbonatebound fractions of Cd and Pb in the soil sample after SRPA application significantly reduced, while the residual fraction increased, indicating the stability of heavy metals increased.

The purpose of the present study is to establish a mixed lubrication model for the journal-thrust coupled microgroove bearings (also referred as coupled bearings) used for the ship shaftless rim-driven thrusters. During the hydrodynamic modelling, the coupling hydrodynamic pressure between the journal bearing and the thrust bearing is considered. The mixed lubrication performances of the microgroove journal-thrust bearing with five different bottom shapes, including rectangle, semi-ellipse, right triangle, isosceles triangle and left triangle, are compared. Based on the numerical results, the optimal microgroove bottom shape of the journal bearing and tilting angle of the thrust pad are determined. Additionally, the comparative analysis shows that the coupled bearing with left triangle microgroove bottom shape exhibits the optimal mixed lubrication performance. The numerical result also indicates that the optimal inclination angle of the thrust bearing pad is 0.01° for the current simulation case.

A complex geometric modeling method of a helical face gear pair with arc-tooth generated by an arc-profile cutting (APC) disc is proposed, and its tooth contact characteristics are analyzed. Firstly, the spatial coordinate system of an APC face gear pair is established based on meshing theory. Combining the coordinate transformation matrix and the tooth profile of the cutter, the equations of the curve envelope of the APC face gear pair are obtained. Then the surface equations are solved to extract the point clouds data by programming in MATLAB, which contains the work surface and the fillet surface of the APC face gear pair. And the complex geometric model of the APC face gear pair is built by fitting its point clouds. At last, through the analysis of the tooth surface contact, the sensitivity of the APC face gear to the different types of mounting errors is obtained. The results show that the APC face gear pair is the most sensitive to mounting errors in the tooth thickness direction, and it should be strictly controlled in the actual application.

Face recognition has been widely used and developed rapidly in recent years. The methods based on sparse representation have made great breakthroughs, and collaborative representation-based classification (CRC) is the typical representative. However, CRC cannot distinguish similar samples well, leading to a wrong classification easily. As an improved method based on CRC, the two-phase test sample sparse representation (TPTSSR) removes the samples that make little contribution to the representation of the testing sample. Nevertheless, only one removal is not sufficient, since some useless samples may still be retained, along with some useful samples maybe being removed randomly. In this work, a novel classifier, called discriminative sparse parameter (DSP) classifier with iterative removal, is proposed for face recognition. The proposed DSP classifier utilizes sparse parameter to measure the representation ability of training samples straight-forward. Moreover, to avoid some useful samples being removed randomly with only one removal, DSP classifier removes most uncorrelated samples gradually with iterations. Extensive experiments on different typical poses, expressions and noisy face datasets are conducted to assess the performance of the proposed DSP classifier. The experimental results demonstrate that DSP classifier achieves a better recognition rate than the well-known SRC, CRC, RRC, RCR, SRMVS, RFSR and TPTSSR classifiers for face recognition in various situations.

Superplasticizers are widely used to reduce the pipe flow resistance of cemented paste backfill (CPB), which is characterised by high concentration and high yield stress. This study aimed to assess the time-dependent rheological properties of CPB containing superplasticizer, with special focus on static yield stress and thixotropy. The results indicate that with the increase of the superplasticizer dosage, the static yield stress, dynamic yield stress and thixotropy of CPB decreased significantly, while the plastic viscosity decreased slightly. The curing time has a significant effect on the static yield stress, dynamic yield stress and thixotropy of CPB containing superplasticizer, which increase by 46.6%–87.1%, 15.2%–35.6% and 79.4%–138.2%, respectively, within 2 h. The static yield stress, dynamic yield stress and thixotropy of CPB without superplasticizer only increase by 4.9%, 6.3% and 16.1%, respectively, within 2 h. The curing time has a significant influence on the plastic viscosity of CPB regardless of superplasticizer addition, the plastic viscosity increases by 13.2%–19.7% within 2 h. Regardless of superplasticizer dosage, plotting of both static yield stress and dynamic yield stress versus thixotropy produces clearly linear curves. The findings of this study are conducive to the design of pipe transportation of CPB containing superplasticizer.

A new type of intelligent geosynthetic product, sensor-enabled geobelt (SEGB), is developed to improve the health monitoring of geotechnical structures. It can be used as a strain monitoring sensor owing to its unique property. As a conductive polymer, its electrical resistance regularly changes with its strain. Simultaneously, the SEGB is a geosynthetic product. This implies that it can be used as a reinforcement to strengthen a geotechnical structure. Therefore, to investigate its long-term mechanical properties within the temperature range of its service, a stress relaxation test is performed within the range of −20 °C to 40 °C. The results show that the stress relaxation of the SEGB stabilizes at a certain stress level instead of decreasing to zero. Additionally, the process of its stress relaxation is accompanied by damage. Based on this phenomenon, a ternary physical constitutive model reflecting the constitutive relationship of the SEGB is established. Furthermore, a stress relaxation model involving damage evolution, temperature, and initial strain is established. It can be used to describe the stress relaxation process of SEGB at different service temperatures.

The frequent occurrence of rockburst and the difficulty in predicting were considered in deep engineering and underground engineering. In this work, laboratory experiments on rockburst under true triaxial conditions were carried out with granite samples. Combined with the deformation characteristics of granite, acoustic emission (AE) technology was well applied in revealing the evolution law of micro-cracks in the process of rockburst. Based on the comprehensive analysis of acoustic emission parameters such as impact, ringing and energy, the phased characteristics of crack propagation and damage evolution in granite were obtained, which were consistent with the stages of rock deformation and failure. Subsequently, based on the critical point theory, the accelerated release characteristics of acoustic emission energy during rockburst were analyzed. Based on the damage theory, the damage evolution model of rock under different loading conditions was proposed, and the prediction interval of rock failure time was ascertained concurrently. Finally, regarding damage as an intermediate variable, the synergetic prediction model of rock failure time was constructed. The feasibility and validity of model were verified.

Rockfill materials have been widely used in the construction of rockfill dam, railway and highway subgrade due to its high filling density, good compaction performance, strong water permeability, small settlement deformation and high bearing capacity. A reasonable constitutive model for rockfill materials is very important for engineering computation and analysis, and has a great development space. Based on the crushing stress and spatial mobilized plane (SMP), a state parameter that can comprehensively reflect the anisotropy and grain crushing is proposed. This state parameter is used to improve the MPZ model (a modifed Zienkiewicz III model), so that a generalized plastic model is constructed to describe the stress and deformation characteristics of rockfill materials in engineering. The validity of the developed model is verified by a series of conventional triaxial tests with different inclination angles of the compaction plane. The variation trend of the constructed anisotropy index ω can reflect the non monotonic variation of the deformation and strength of rockfill with the direction angle of large principal stress, so the model can reflect the obvious difference caused by the initial anisotropy of rockfill on the mechanical properties.

The asymmetric semi-circular bend (ASCB) specimen has been proposed to investigate the cracking behavior in different geo and construction materials and attracted the attention of researchers due to its advantages. However, there are few studies on the fracture toughness determination of rock materials. In this work, a series of fracture tests were performed with the ASCB specimens made of granite. The onset of fracture, crack initiation angle and crack propagating trajectory was analyzed in detail combined with several mixed mode fracture criteria. The influence of the crack length on the mode I/II fracture toughness was studied. A comparison between the fracture toughness ratios predicted by varying criteria and experimental results was conducted. The relationship between experimentally determined crack initiation angles and curves of the generalized maximum tangential stress (GMTS) criterion was obtained. The fracture process of the specimen was recorded with the high-speed camera. The shortcomings of the ASCB specimens for the fracture toughness determination of rock materials were discussed. The results may provide a reference for analysis of mixed mode I and II fracture behavior of brittle materials.

for a deeper understanding of the deformation failure behavior of jointed rock, numerical compression simulations are carried out on a rock specimen containing non-persistent joints under confining pressure with the bonded-particle model. The microscopic parameters which can reflect the macroscopic mechanical properties and failure behavior of artificial jointed specimens are firstly calibrated. Then, the influence of joint inclination and confining pressure on stress — strain curves, crack patterns, and contact force distributions of jointed rock are investigated. The simulation results show that both the compressive strength and elastic modulus of the specimens increase with increasing confining pressure, and these two mechanical parameters decrease first and then increase with the increase of joints inclination. The sensitivity of strength and elastic modulus to confining pressure is not the same in different joints inclinations, which has the least impact on specimens with α =90°. Under low confining pressure, the failure modes are controlled by the joint inclination. As the confining pressure increased, the initiation and propagation of tensile crack are gradually inhibited, and the failure mode is transferred from tensile failure to shear-compression failure. Finally, the reinforcement effect of prestressed bolt support on engineering fractured rock mass is discussed.

To obviate the complexities of the straight forward couple stress finite element method, the penalty-based couple stress finite element method (named PcouFEM) within the framework of the Cosserat continuum is utilized to obtain the approximate solution by relaxing the C¹ continuity. To examine the performance of the PcouFEM, three well-known numerical examples are investigated. For the analysis on stress concentration around the circular hole of the planestrain specimen, it was found that as long as the penalty factor G_c is not less than 5 times the shear modulus of the classical continuum G (i. e., G_c⩾5G), the stress concentration factors calculated by the PcouFEM with the reduced integration scheme agree well with the analytical solutions. For the strain localization analysis in the uniaxial compression test, it was observed that by applying the PcouFEM, the pathologically mesh-dependent problem associated with the conventional FEM can be alleviated or even removed, and based on numerical simulations, it is recommended to define 5G⩽G_c⩽10G from the perspective of numerical accuracy. For the soil slope subjected to an eccentric load through the rigid strip footing, it was found that the mesh-dependent problem of the shear band simulation can be largely alleviated by applying the PcouFEM.

To investigate the influence of temperature on the physical, mechanical and acoustic emission characteristics of granites, uniaxial compression test, variable-angle shear test, acoustic emission signal monitoring and the measurement of physical parameters including mass, size and P-wave velocity were carried out on granite samples treated at temperatures T ranging from 25 to 900 ° C. The results show that the density and P-wave velocity decrease gradually with increasing T. As the temperature increases, the peak compressive stress decreases while the peak strain increases, due to the fact that a high temperature induces the escaping of waters within granites, the expanding of mineral grains and the generations of fractures. With the increment of T, both the peak shear stress and the cohesion decrease, whereas the frictional angle increases. During the compressing and shearing tests, the maximum acoustic emission counts show a decreasing trend when T increases from 25 to 900 °C. When T exceeds 573 °C, the crystal lattice structure of quartz changes from α-phase to β-phase, decreasing the mechanical behavior of granites to a great extent. In addition, the results also indicate that T=500–600 °C is the critical temperature ramge to characterize the influence of temperature on the physical, mechanical and acoustic emission characteristics of granites.

This study investigates the factors affecting the rock-breaking efficiency of the TBM disc cutter in deep rock excavation, including confining pressure, penetration, cutter spacing, and revolution speed. The finite element method is employed to formulate a rock-breaking model of the rotary disc cutters and a numerical simulation is also implemented. The rock breaking effect, rock breaking volume, and rock breaking specific energy consumption under different combinations of the factors are investigated. An orthogonal test of four factors at four levels was constructed. Based on the test results and range analysis in the process of deep rock mass breaking, the order of sensitivity of each influencing factor with respect to the rock breaking specific energy for the disc cutter is cutter spacing > revolution speed > penetration > confining pressure. By constructing a numerical simulation comparison scheme, the orthogonal test results are analyzed and corroborated, and the rock breaking law and rock breaking efficiency under different influencing factors are derived. Finally, the sensitivity of different influencing factors on the rock-breaking efficiency is verified.

This study aims to reveal the macroscopic permanent deformation (PD) behavior and the internal structural evolution of construction and demolition waste (CDW) under loading. Firstly, the initial matric suction of CDW was measured by the filter paper method. Secondly, the PD of CDW with different humidity and stress states was investigated by repeated load triaxial tests, and a comprehensive prediction model was established. Finally, the discrete element method was performed to analyze the internal structural evolution of CDW during deformation. These results showed that the VAN-GENUCHTEN model could describe the soil-water characteristic curve of CDW well. The PD increases with the increase of the deviator stress and the number of cyclic loading, but the opposite trend was observed when the initial matric suction and confining pressure increased. The proposed model in this study provides a satisfactory prediction of PD. The discrete element method could accurately simulate the macroscopic PD of CDW, and the shear force, interlock force and sliding content increase with the increase of deviator stress during the deformation. The research could provide useful reference for the deformation stability analysis of CDW under cyclic loading.

To explore the influence of intelligent highways and advanced traveler information systems (ATIS) on path choice behavior, a day-to-day (DTD) traffic flow evolution model with information from intelligent highways and ATIS is proposed, whereby the network reliability and experiential learning theory are introduced into the decision process for the travelers’ route choice. The intelligent highway serves all the travelers who drive on it, whereas ATIS serves vehicles equipped with information systems. Travelers who drive on intelligent highways or vehicles equipped with ATIS determine their trip routes based on real-time traffic information, whereas other travelers use both the road network conditions from the previous day and historical travel experience to choose a route. Both roadway capacity degradation and travel demand fluctuations are considered to demonstrate the uncertainties in the network. The theory of traffic network flow is developed to build a DTD model considering information from intelligent highway and ATIS. The fixed point theorem is adopted to investigate the equivalence, existence and stability of the proposed DTD model. Numerical examples illustrate that using a high confidence level and weight parameter for the traffic flow reduces the stability of the proposed model. The traffic flow reaches a steady state as travelers’ routes shift with repetitive learning of road conditions. The proposed model can be used to formulate scientific traffic organization and diversion schemes during road expansion or reconstruction.

Short-term traffic flow forecasting is a significant part of intelligent transportation system. In some traffic control scenarios, obtaining future traffic flow in advance is conducive to highway management department to have sufficient time to formulate corresponding traffic flow control measures. In hence, it is meaningful to establish an accurate short-term traffic flow method and provide reference for peak traffic flow warning. This paper proposed a new hybrid model for traffic flow forecasting, which is composed of the variational mode decomposition (VMD) method, the group method of data handling (GMDH) neural network, bi-directional long and short term memory (BILSTM) network and ELMAN network, and is optimized by the imperialist competitive algorithm (ICA) method. To illustrate the performance of the proposed model, there are several comparative experiments between the proposed model and other models. The experiment results show that 1) BILSTM network, GMDH network and ELMAN network have better predictive performance than other single models; 2) VMD can significantly improve the predictive performance of the ICA-GMDH-BILSTM-ELMAN model. The effect of VMD method is better than that of EEMD method and FEEMD method. To conclude, the proposed model which is made up of the VMD method, the ICA method, the BILSTM network, the GMDH network and the ELMAN network has excellent predictive ability for traffic flow series.