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Not all precast concrete structures show performance that can be obtained by experiment. Finite element analysis also plays a vital role in the study of structural performance. In this paper, a steel hysteretic is employed to reproduce the experimental response of a steel strand anchored precast concrete frame joints exposed to reversed cyclic load tests. The ultimate load and ultimate displacement obtained by finite element calculation are not more than 1% different from the experimental values. By employing the proposed model, the hysteretic curve, energy dissipation capacity, stiffness degradation, and displacement ductility of the reactive powder concrete (RPC) interior beam–column joints were analyzed. According to the analysis, in the case of the failure morphology of RPC beam-to-column joints with friction dampers, it is evident that the plastic hinge at the end of beam had shifted outward. In addition, both the energy dissipation capacity and the ultimate bearing capacity of the RPC interior beam–column joints have been improved, the ultimate load of PC2 is 28.8% higher than that of PC1. According to the aforementioned results, the parametric analysis of the RPC interior beam–column joint was performed. Subsequently, by varying the friction coefficient of the friction damper, the stirrup spacing in the panel zone and the different axial compression ratios, the influence of a number of different parameters on the mechanical properties of the joint was obtained.

In this study, we report the results of an experimental investigation conducted under a four-point bending loading in order to evaluate the shear performance of concrete beams reinforced with basalt fiber without web reinforcement. According to the experimental results, it is evident that the final failure morphology of concrete-basalt fiber concrete composite beams and conventional concrete beams was shear failure, whereas the failure morphology of concrete beams reinforced with full basalt fiber was bending failure. Moreover, the results also indicate that the cracking load and ultimate bearing capacity of concrete composite beams reinforced with concrete-basalt fiber are lower than those of conventional concrete beam. This is mainly due to the interface between ordinary post-cast concrete and concrete reinforced with hardened basalt fiber. Due to the superior tensile properties of fiber, composite beams and all basalt fiber concrete beams exhibit a higher degree of ductility than conventional concrete beams. Utilizing the existing calculation theory for concrete beams reinforced with fiber, it was calculated that the cracking load and ultimate load of basalt fiber beams were calculated, and the calculation results were consistent with the experimental results. Based on the results of the evaluation and the theoretical analysis, this study proposes a finite element modeling method for basalt fiber composite beams. The results of the analysis were consistent with the experimental results of all investigated beams. The established model was employed in order to investigate the influence of shear span ratio on the shear performance of basalt fiber beams.

The seismic performance index of prefabricated structures is generally obtained via experimental analysis. However, in experimental research, it is impossible that every influencing factor can be taken into account. Therefore, the finite element analysis method can be used as a supplementary method for experimental research to carry out parametric analysis of joints. Based on this test, a hysteretic model of steel bars is developed on the ABAQUS platform; meanwhile, the model is used to simulate the seismic analysis of the proposed local reinforced joints. The hysteresis curve obtained via simulation exhibits a high degree of coincidence with the experimental results. Based on the validated model, a detailed parameter analysis of prefabricated local reinforced concrete frame joints is carried out. The analysis results illustrate that the axial pressure ratio at the top of the column has a minimal impact on the joint's performance. Decreasing the stirrup ratio within the core region, enlarging the diameter of the PC steel bar, and increasing the concrete strength that is poured in the keyway and the core region can raise the cumulative energy consumption of the joints, thereby reducing the damage degree of other units and improving the maximum bearing capability of the joints. [ABSTRACT FROM AUTHOR]

In contrast to the marine environment, coastal regions encompass substantial saline soils characterized by complex corrosive chemical compositions. This poses notable challenges to the durability of concrete structures erected in coastal dredger fill silty soil environments. This research undertook concrete chloride corrosion assessments in both a dredger fill silty soil environment and a simulated solution environment. The findings demonstrated a progressive escalation in the free chloride concentration within concrete specimens, as the exposure duration was extended from 60 to 120 d, and discernible convection zones were observed with depths ranging from 6 to 8 mm. The investigation revealed a diminishing trend in the apparent chloride diffusion coefficient, corresponding to the elongation of exposure time and the augmentation of burial depth. Paradoxically, the burial depth and exposure duration exhibited converse effects on the apparent surface chloride concentration. Empirical formulations were derived to express the apparent surface chloride concentrations and apparent chloride diffusion coefficients as dependent on the exposure time and burial depth variables. These models exhibited an excellent goodness of fit, reaching up to 0.96. Notably, concrete specimens interred at a depth of 0.0 m displayed a favorable likeness to the simulated solution environment throughout the 60 d exposure period. [ABSTRACT FROM AUTHOR]

The flow behaviors of ultrahigh strength steel BR1500HS at elevated temperature were studied by performing hot tension tests at the temperatures of 773 K, 873 K, 1023 K and 1173 K, and strain rates of 0.01 s−1, 0.1 s−1 and 1 s−1 on a Gleeble 3500 thermo-mechanical simulator. The true stress-strain curves were obtained and their characteristics were analyzed. Relationships among the maximum stress, temperature and strain rate were described by means of the conventional hyperbolic sine equation. The average deformation activation energy in the whole deformation temperatures was determined as Q = 235.257 KJ/mol by regression analysis. Based on σ(dσ/dε) verse σ2 curves, the values of dynamic recovery (DRV) rate coefficient, r, saturated stress, σrec, and yield strength, σ0, under different deformation conditions were calculated. In order to estimate the DRV volume fractions, the modified Avrami type equation including r (r = 106.911351Z−0.059) as a function of the temperature compensating parameter, Z, was established, and then the effects of deformation conditions on the DRV kinetics were described in details.

Several aryl hydrocarbon receptor (AhR) agonists have been reported to promote the generation of regulatory T cells (Treg cells), and the action mechanisms need to be identified. In this study, we addressed the underlying mechanism of AhR activation to induce the generation of Treg cells in the view of cellular metabolism. Naïve CD4+ T cells were purified with mouse CD4+ CD62L+ T Cells Isolation Kits. The proportions of Treg cells were detected by flow cytometry. The value of oxygen consumption rate (OCR) of CD4+ T cells was detected by the Seahorse XFe 96 analyzer. The activation of fatty acid oxidation (FAO)‐related metabolic pathways was detected by Western blotting. Intracellular localization of Lkb1 was detected by immunofluorescence. The Strad‐Mo25‐Lkb1 complex formation and K63 chain ubiquitination modification of Lkb1 were detected by co‐immunoprecipitation. The binding of AhR to the Skp2 promoter was detected by constructing luciferase reporter gene. AhR or carnitine palmitoyltransferases 1 was knockdown in dextran sulphate sodium (DSS)‐induced colitis or collagen‐induced arthritis (CIA) mice by infecting mice with adeno‐associated virus via the tail vein injection. Compared to the control group, exogenous and endogenous AhR agonists 3,3′‐diindolylmethane (DIM) and 2‐(1′H‐indole‐3′‐carbonyl)‐thiazole‐4‐carboxylic acid methyl ester (ITE) were shown to preferentially upregulate the mRNA expression of FAO‐related enzymes and the value of OCR. Consistently, pharmacological or genetic inhibition of FAO markedly diminished the induction of DIM and ITE on the differentiation of Treg cells. DIM and ITE functioned mainly through activating the liver kinase B1 (Lkb1)‐AMPK pathway via promotion of Lkb1‐Strad‐Mo25 complex formation and Lkb1 K63 ubiquitination. DIM and ITE were also shown to upregulate the mRNA expression of Skp2, a ubiquitination‐related enzyme, and facilitate the binding of AhR to the xenobiotic responsive element of Skp2 promoter region by luciferase reporter gene assay. Furthermore, the contribution of Skp2/K63 ubiquitination/Lkb1/FAO axis was verified in (DSS)‐induced colitis or CIA mice. In summary, these findings indicate that AhR activation promotes Treg cell generation by enhancing Lkb1‐mediated FAO via the Skp2/K63‐ubiquitination pathway, and AhR agonists may be used as inducers of Treg cells to prevent and treat autoimmune diseases. [ABSTRACT FROM AUTHOR]

In this work, HfGdOx gate dielectric thin films have been prepared via a nontoxic and environmental-friendly fully water-driven (WD) method. An in-depth investigation has been conducted to reveal the evolution of physical properties in the as-prepared HfGdOx thin films as a function of annealing temperature. Based on the measurements of electrical parameters of the HfGdOx thin films, it is observed that the 500 °C-annealed HfGdOx thin films have shown optimized properties, including a smooth surface, lower leakage current density, and a larger areal capacitance. To validate the feasibility of the HfGdOx gate dielectrics in thin-film transistors (TFTs), In2O3/HfGdOx TFTs have been constructed. The optimized In2O3/HfGdOx TFT exhibited excellent electrical performances, including high field-effect mobility of 11.2 cm2 V−1 s−1, a high ON-/OFF-state current ratio of 4.1 × 106, a small sub-threshold swing of 105.2 mV/decade, and a threshold voltage shift of 0.58 V after 7200-s bias stress, respectively. Finally, based on the In2O3/HfGdOx TFT, an inverter is assembled by connecting an external 3-MΩ resistor. High gain of 8.73 and excellent swing characteristics have been obtained. As a result, it can be inferred that fully WD In2O3/HfGdOx TFTs with high performance will pave the way for achieving low-power-consumption, low-cost, and large-area electronics. [ABSTRACT FROM AUTHOR]

In this article, novel ZrAlOx gate dielectric films were fabricated by a simple, low-cost, and environmentally, eco-friendly, fully water-induced (WI) method for the first time. The microstructure, optical transmittance, surface topography, chemical compositions, and electrical properties of WI ZrAlOx films annealed at 300 °C–600 °C were characterized. Experimental results demonstrated that the 500 °C-annealed WI ZrAlOx film has a good amorphous state, high transmittance, very smooth surface morphology, large area capacitance, and low leakage current density. In order to verify the feasibility of the 500 °C-annealed ZrAlOx film as a dielectric in thin-film transistor (TFT) devices, In2O3/ZrAlOx TFTs were successfully fabricated. The optimized 270 °C-annealed TFT devices have shown excellent electrical characteristics at an extremely low operating voltage of 3 V, including a high $\mu _{{\text {FE}}}$ of 10.14 cm2V−1S−1, a high ${I}_{{\text {on}}}/{I}_{{\text {off}}}$ of ~ 106, a small subthreshold slope (SS) (100 mV dec−1), a low ${V}_{{\text {TH}}}$ (0.36 V), and a small ${N}_{S}^{{\text {max}}}$ ($2.15\times {10}^{{12}}$ cm−2), respectively. To further explore the potential application of In2O3/ZrAlOx TFTs in digital circuits, a resistor-loaded inverter has been constructed and presented good voltage transfer characteristics and high voltage gain. In addition, the dynamic behavior with full swing characteristics has been obtained at a low ${V}_{{\text {DD}}}$ of 2 V. These excellent parameters show their great potential for application in low cost, highly transparent, portable, and low-power consumption electronics. [ABSTRACT FROM AUTHOR]