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Abstract Splitting tensile strength (STS) is an important mechanical property of concrete. Modeling and predicting the STS of concrete containing Metakaolin is an important method for analyzing the mechanical properties. In this paper, four machine learning models, namely, Artificial Neural Network (ANN), support vector regression (SVR), random forest (RF), and Gradient Boosting Decision Tree (GBDT) were employed to predict the STS. The comprehensive comparison of predictive performance was conducted using evaluation metrics. The results indicate that, compared to other models, the GBDT model exhibits the best test performance with an R2 of 0.967, surpassing the values for ANN at 0.949, SVR at 0.963, and RF at 0.947. The other four error metrics are also the smallest among the models, with MSE = 0.041, RMSE = 0.204, MAE = 0.146, and MAPE = 4.856%. This model can serve as a prediction tool for STS in concrete containing Metakaolin, assisting or partially replacing laboratory compression tests, thereby saving costs and time. Moreover, the feature importance of input variables was investigated.

The overpressure of silo wall caused by granular materials under earthquake is one of the main reasons of silo damage. Two shaking table model tests were carried out with column supported silos and independent single silos, respectively. The seismic response of silo granular materials was analyzed first, and then the dynamic lateral pressure of silo wall under different levels of earthquake and overpressure coefficient were obtained. The results showed that the interaction between the granular materials and the silo wall in the group silos is related to the position of the individual silo. The seismic response of granular materials is linked with the spectral characteristics of seismic waves. The overpressure coefficients of the corner silo and the side silo are greater than that of the independent single silo with a 7% and 9% higher value, respectively. Apparently, the seismic response characteristics of the independent single silo are totally different from that of the group silos. It was concluded that when designing the wall of the group bin, the position of the bin should also be considered.

Irregularity in the plane layout of a building structure and the vertical discontinuity of lateral resistance components could lead to torsion and result in the brittle failure of a structure. According to the characteristics of the conventional island main building of nuclear power plants, this paper focuses on the conventional island main building of the CAP1400 nuclear power plant (NPP) in Shidaowan as the research object. A prototype structure model of the main building was developed using ABAQUS software. The seismic response of the structure under multidimensional ground motion was studied by inputting the X-direction and Y-direction translational and torsional components of ground motion in ABAQUS. The results demonstrate that the overall transverse displacement of the structure under bidirectional ground motion was significantly higher than that under unidirectional earthquakes, which was about 20%. Under a multidimensional frequent earthquake, the transverse displacement of the structure increased by about 13% on average compared with that under a bidirectional earthquake; the longitudinal increase was the largest, at about 28%. Finally, the lateral displacement of each layer of the steel-reinforced concrete (SRC) frame-bent main building structure with few walls proposed in this article decreased by an average of about 17% compared to the traditional SRC frame-bent main building structure. The longitudinal displacement was reduced by about 14% compared to the traditional SRC frame-bent main building structure.

As a new type of grain barn wall component, the “Structure-Insulation” integrated wall panel (SIW) has excellent characteristics such as a high-bearing capacity and good insulation performance. In order to study its mechanical properties under grain load, this paper designed three wall panels with different thicknesses, carried out static loading tests on them, studied their cracking and ultimate load, and analyzed the development trend of the wall panel’s crack and deflection. In order to study the reliability of wall panels under stochastic conditions, the performance functions of the wall panel under deflection and strength control conditions were established. The reliability analysis was carried out by using the response surface method and finite element software. The sensitivity degree of each random parameter to different performance functions was quantified. The results show that, under the maximum grain load condition, the deflection of the designed specimens is less than l0/250, and the crack width is less than 0.2 mm, both of which meet the requirements of the normal use limit state. The cracking loads of the three specimens are 13.02, 14.75, and 16.49 kN/m2, respectively, with corresponding crack widths of 0.06, 0.07, and 0.06 mm. The ultimate load is 65.1, 75.52, and 82.47 kN/m2, with corresponding maximum crack widths of 1.66, 1.60, and 1.61 mm, respectively. The reliability indexes of the deflection and strength of the thinnest specimens are β1=2.60 and β2=3.26, respectively, which meet the safety conditions of ductile failure. The parameter affecting the reliability of concrete deflection is the grain gravity density, with a correlation coefficient of −0.707. The parameter affecting the reliability of concrete strength is concrete strength, with a correlation coefficient of 0.935. Combined with the static load test and reliability analysis, the designed wall panel can meet the normal use of grain under full load and has good reliability. Sensitivity analysis can provide a reference for the optimization of practical engineering design.

Abstract Controlled‐release nitrogen fertilizer (CRNF) is expected to meet the nutrient demands for crop growth with single fertilizer application, so as to achieve high‐yield, high‐efficiency, and labor‐saving cultivation. However, under current CRNF practices, a single application of CRNF in winter wheat (Triticum aestivum L.) usually fails to achieve satisfactory effects due to insufficient nitrogen (N) supply in the later growth stage, contributing to premature leaf senescence and poor grain filling. To determine a reasonable CRNF application strategy for improving the grain weight and yield of winter wheat, the responses of leaf senescence, photosynthetic capacity, grain‐filling characteristics, and grain yield to different CRNF types [polymer‐coated urea (PCU), sulfur‐coated urea (SCU), and urea‐formaldehyde (UF)] and fertilization practices [single fertilization (P1) and twice‐split fertilization (P2)] were investigated. The results showed that, compared with P1, P2 increased the activities of catalase, peroxidase, and superoxide dismutase, alleviated the accumulation of malondialdehyde, delayed flag leaf senescence, and enhanced the net photosynthetic rate (Pn) of the flag leaves, which promoted assimilate accumulation and transport to the grains. These advantages in P2 improved the grain‐filling process of wheat, with the active filling duration (T), average filling rate (G), and maximum filling rate (Gmax) in P2 all being higher than those in P1, which significantly increased the 1000‐grain weight (TGW) and grain yield of wheat. Among the three CRNFs, PCU showed advantages in Pn at the milk‐ripe stage (Zadoks growth stage, GS75), dry matter accumulation post‐anthesis, T, Gmax, and G, which contributed to TGW and grain yield. Overall, our study suggested that the twice‐split application of CRNF could substantially delay leaf senescence post‐anthesis and increase photosynthetic capacity, thus improving grain filling and productivity in winter wheat.

The walls of grain cottage silos are still being built by clay brick masonry featured with single-structure form, poor air tightness, large workload of manual masonry on site, and huge consumption of raw materials and burning materials, which is not conducive to energy saving and environmental protection. In order to study the mechanical function of the new wall under the action of grain side pressure, the static loading test was conducted on the model of scaled-down wall panel under the action of side pressure. The damage process, the damage pattern, and the bearing capacity of the wall panel were studied through the analysis of the crack development process and distribution law to reveal the force characteristics of the wall panel. The test results show that the span deflection of the “structure-insulation” integrated wall panel under the lateral pressure meets the requirement of the limit state of normal use; the inner and outer leaf wall panels can work together under the action of the joint; the ratio of the load borne by the inner and outer leaf wall panels is equal to the ratio of their stiffness; the flexural stiffness of the wall panels after cracking is proposed based on the combined effect analysis. Based on the analysis of the combined effect, the degradation factor of the wall panel after cracking is proposed, and the deflection calculation formula of the inner and outer leaf wall panel is established, which provides a theoretical basis for the design and the promotion of the “structure-insulation” integrated wall panel.

The main purpose of this study was to investigate the flexural behavior of high-ductility fiber-reinforced concrete (HDC) and propose a suitable method for evaluating flexural toughness. The flexural strength, deformation, and toughness of HDC were investigated through four-point bending tests with specimens of 40 × 40 × 160 mm. The test parameters were fiber volume fractions (0%, 1%, 1.5%, and 2%), water–binder ratios (0.24, 0.26, 0.29, and 0.32), and ages (28 d and 56 d). The experimental results showed that polyvinyl alcohol (PVA) fibers led to significant improvement in the flexural behavior of HDC due to its strain-hardening behavior and excellent crack dispersion capacity. The ultimate flexural strength of HDC with 2% PVA fibers of about 15.32 MPa showed an increase of up to 221%. The deformation and flexural toughness ratios were 23 times and 1.43 times higher, respectively, than the specimens without fibers. A simple and practical method for evaluating the flexural toughness of HDC was proposed, which solved many problems with the existing methods. This method made full use of the peak load, which overcame the difficulty of identifying the initial crack information, solved the insufficient deflection limit, and provided a more comprehensive and accurate evaluation by selecting characteristic points evenly distributed throughout the loading process.

The traditional brick bungalow is not conducive to long-term grain storage because of its poor thermal insulation. In this paper, a new type of wall element for grain bungalows with both load-carrying and thermal insulation functions, called a “Structure-Insulation” integrated wall panel (SIW), is proposed for improving the grain storage environment. To study the thermal insulation reliability of SIW under multivariable randomness and the availability of different grain storage zones, a finite element model was established based on the test. Then, the failure criterion was established with the heat transfer coefficient as the key point and 1,000,000 sampling calculations were carried out by the Monte Carlo method. The reliability was discussed and sensitivity of random parameters was quantified. The thermal performance test shows that the heat transfer coefficients of the two designed SIW wall panels compared with the traditional brick bungalow wall are reduced by 45.81% and 56.13%, respectively. The thickness of the insulation panel is sensitive mostly to the thermal insulation performance, with a correlation coefficient of 0.877. When the thickness of the insulation panel is 80, 94, and 107 mm, the wall panel can meet the limit requirements of the heat transfer coefficient of the granary enclosure structure of 0.59, 0.53, and 0.46 W/m2·K, with reliability indexes of 3.08, 1.82, and 1.75, respectively. The research results provide an important reference for the design, optimization, and application of SIW wall panels in thermal insulation.

Ca-alginate beads have strong hygroscopicity, which have been used for the self-healing and internal curing of cement-based materials. However, ca-alginate beads in cement will chelate with calcium ions, which decreases the swelling rate of ca-alginate beads in the healing environment and is detrimental to the self-healing of cement-based materials. In this paper, the mechanism and steps for preparing ca-alginate beads with a lower ability to chelate with calcium ions were proposed based on protonation theory. In addition, the molecular structure and the swelling rates in cement filtrate and healing environment of ca-alginate beads prepared by the proposed method were characterized. The results showed that the ca-alginate beads prepared by the proposed method had higher molecular density and a lower ability to chelate with calcium ions. The swelling rate in the healing environment is not decreased. Furthermore, the equilibrium swelling rate in cement filtrate can satisfy the need for internal curing of cement-based materials.

The TUBBY gene family is a group of transcription factors found in animals and plants with many functions. TLP genes have a significant role in response to different abiotic stresses. However, there is limited knowledge regarding the TUBBY gene family in T. aestivum. Here we identified 40 TaTLP genes in wheat to reveal their potential function. This study found that TUBBY (TaTLP) genes are highly conserved in wheat. The GO analysis of TaTLP genes revealed their role in growth and stress responses. Promoter analysis revealed that most TaTLPs participate in hormone and abiotic stress responses. The heatmap analysis also showed that TaTLP genes showed expression under various hormonal and abiotic stress conditions. Several genes were upregulated under different hormonal and temperature stresses. The qRT-PCR analysis confirmed our hypotheses. The results clearly indicate that various TaTLP genes showed high expression under temperature stress conditions. Furthermore, the results showed that TaTLP genes are expressed in multiple tissues with different expression patterns. For the first time in wheat, we present a comprehensive TaTLP analysis. These findings provide valuable clues for future research about the role of TLPs in the abiotic stress process in plants. Overall, the research outcomes can serve as a model for improving wheat quality through genetic engineering.

Environmental conditions (precipitation, temperature and soil properties) differ greatly in different regions and have dual effects on the wheat growth and nutrient release of slow-release fertilizer (SRF). Conventional fertilization methods such as the multiple-split application of urea and the one-time application of SRF may have difficulty achieving a stable and high wheat yield and nitrogen (N) efficiency in various environments. Therefore, the exploration of a rational application strategy of SRF is needed for improving wheat yield and its stability in different regions. A two-year field experiment was conducted in different regions (eight test sites per year) with five patterns: 100% N (270 kg ha−1) SRF applied pre-sowing (M1); 60% N SRF applied pre-sowing and 40% N urea applied at jointing (M2); 60% N SRF applied pre-sowing and 40% N SRF applied at re-greening (M3); M2 reducing the N rate by 15% (M4); M3 reducing the N rate by 15% (M5). The fourth-split application of urea was taken as the control (CK, 270 kg N ha−1). The results suggested that the average yield in M1 decreased by 3.65% of the CK, and the yield stability was poor. Both M2 and M3 significantly increased N efficiency, grain yield and benefit, but the stability of M3 was higher than that of M2 in different environments. Considering further improvements in wheat yield, N efficiency and profit, our results suggested that the twice-split application of SRF, which also improved the adaptability of wheat in different environments, could be recommended for wheat cultivation.

Global warming has changed the suitability of areas traditionally planted with crops, raising concerns about cereal security. To investigate the possibilities and constraints of increasing yields by breaking through traditional area plantings of wheat cultivars, a two-year field experiment was conducted in southern and northern locations in the Yangtze River basin (YRB), China (separated by approximately 180 km), with seven weak-winter types and six semi-winter types, respectively, bred for the two regions. The movement of weak-winter-type cultivars to the north increased or did not change grain yield and their grain yields were not significantly higher than those of local semi-winter-type cultivars. The movement of semi-winter-type cultivars to the south significantly decreased their yields. Thus, breaking through traditional area plantings did not significantly increase grain yields compared with those of local wheat cultivars. Grain yield of wheat planted in the northern YRB was higher by 5 to 20% than that in the southern YRB because of an increase in spikes that resulted from a longer spike formation phase. In addition, the post-anthesis leaf area declined more slowly in the northern YRB because of higher main stem and tiller survival. High-yielding cultivars always had more spikes and larger photosynthetic areas after anthesis than those of low-yielding cultivars regardless of the planting locations, which led to increases in post-anthesis biomass. However, the grain yield of different cultivars was highly variable under different environmental conditions. The coefficient of variation (CV) of grain yield in different cultivars was significantly positively correlated with the CV of spike number and post-anthesis biomass, implying that flexibility spike number and post-anthesis biomass in response to environmental changes can maximize release of yield potential. Therefore, improving main stem and tiller survival can increase spike number and maintain post-anthesis photosynthetic areas and help to establish a large, highly stable, and productive population with a high level of suitability and production through effectively utilizing the resources during the late growth phase. Valuable suggestions for breeding high-yield and -stability cultivars and confirming their planting range in the future are given.

The development of crop cultivars with high nitrogen use efficiency (NUE) under low-N fertilizer inputs is imperative for sustainable agriculture. However, there has been little research on the molecular mechanisms underlying enhanced resilience to low N in high-NUE plants. The comparison of the transcriptional responses of genotypes contrasting for NUE will facilitate an understanding of the key molecular mechanism of wheat resilience to low-N stress. In the current study, the RNA sequencing (RNA-seq) technique was employed to investigate the genotypic difference in response to N deficiency between two wheat NILs (1Y, high-NUE, and 1W, low-NUE). In our research, high- and low-NUE wheat NILs showed different patterns of gene expression under N-deficient conditions, and these N-responsive genes were classified into two major classes, including “frontloaded genes” and “relatively upregulated genes”. In total, 103 and 45 genes were identified as frontloaded genes in high-NUE and low-NUE wheat, respectively. In summary, our study might provide potential directions for further understanding the molecular mechanism of high-NUE genotypes adapting to low-N stress.

Nitrogen (N) is an essential nutrient element for crop productivity. Unfortunately, the nitrogen use efficiency (NUE) of crop plants gradually decreases with the increase of the N application rate. Nevertheless, little has been known about the molecular mechanisms of differences in NUE among genotypes of wheat. In this study, we used RNA-Sequencing (RNA-Seq) to compare the transcriptome profiling of flag leaves at the stage of anthesis in wheat NILs (1Y, high-NUE, and 1W, low-NUE) under normal nitrogen conditions (300 kg N ha−1, corresponding to 1.6 g N pot−1). We identified 7023 DEGs (4738 upregulated and 2285 downregulated) in the comparison between lines 1Y and 1W. The responses of 1Y and 1W to normal N differed in the transcriptional regulatory mechanisms. Several genes belonging to the GS and GOGAT gene families were upregulated in 1Y compared with 1W, and the enhanced carbon metabolism might lead 1Y to produce more C skeletons, metabolic energy, and reductants for nitrogen metabolism. A subset of transcription factors (TFs) family members, such as ERF, WRKY, NAC, and MYB, were also identified. Collectively, these identified candidate genes provided new information for a further understanding of the genotypic difference in NUE.

This paper introduces an optimal design method of swept blades for Horizontal Axis Wind Turbines, which comprehensively takes both annual energy production (AEP) and blade root loads into account. The start position of sweep curve, tip sweep, and the first-order derivative of the sweep curve at tip are design variables, Maximum AEP and minimum blade root loads are optimization objectives; meanwhile, non-dominated sorting genetic algorithm II is applied to find the optimal result. The sweep curve is modeled by a three order polynomial, while power coefficient CP and AEP are calculated by blade element and momentum method, and blade root loads are evaluated by GH Bladed. A sweep curve design case is demonstrated in this paper. AEP, extreme and damage equivalent load (DEL) of blade root My of the optimal result, is evaluated. By adding the backward sweep curve to the baseline blade, AEP is increased by 1.34%, My extreme load is significantly dropped, Mx extreme load is almost the same as the baseline, while Mz extreme load is increased in low wind speed. Furthermore, all of the DELs of Mx, My, and Mz are reduced except at the wind speed range near rated wind speed. This was due to the same controller parameter as the baseline. [ABSTRACT FROM AUTHOR]