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Acoustic emission (AE) can monitor and evaluate the cracking situations of hydraulic structures for it is real-time and non-destructive. However, a current challenge of this approach is to accurately identify the various stages during the cracking process. The innovation of this paper lies in the application of AE data in analyzing the stage characteristics during the whole process of hydraulic concrete fracture. First, the slope changing of the cumulative ringing count curve was used to determine the cracking stages of hydraulic concrete. Second, the function of inter-event times (denoted as F-function) was used to further investigate the AE characteristics proximity to the final fracture. Last, the spatial-temporal-energy evolution of cracks was studied. The results show that: (1) The whole process of hydraulic concrete failure shows an obvious stage characteristic from the perspective of AE feature and it can be distinguished to five stages by the slope change of the cumulative ringing count curve; (2) The F-function can be used to identify the last two cracking stages, and it is capable of early warning the macroscopic cracking in ahead of b-value; (3) The spatial-temporal-energy distribution of cracks helps to better understanding the generation and evolution for cracks inside hydraulic concrete. [ABSTRACT FROM AUTHOR]

Abstract During its long process of serving time, roller compacted concrete (RCC) arch dam effected by the comprehensive combination of many factors shows a typical time-varying characteristic on its structure and material properties, which is objectively reflected in the prototype monitoring data. On the basis of the analysis on influence variables of dam deformation and the working mechanism of the RCC arch dam, in this paper, time-varying early-warning model for the RCC arch dam is established by introducing time-varying factors into hydrostatic pressure components and expanding temperature components, then the modeling method of time-varying early-warning model above is proposed combined with the partial least squares algorithm and genetic algorithm. [ABSTRACT FROM AUTHOR]

• Excessively wide mulched-ridge cannot significantly increase soil water storage. • Ridge soil temperature increased and furrow's decreased with mulched ridge width. • Appropriate ridge-furrow ratio can mitigate the impact of drought on wheat yield. • Optimal ridge width for the water-related resource was higher than thermal resource. • The optimal mulched-ridge and furrow was both 60 cm for winter wheat. The plastic-mulched ridge and furrow rainwater harvesting (PRFRH) system improves precipitation utilization and yield in semi-arid regions. For densely planted crops such as winter wheat, however, the ridges reduce planting area. Thus, optimal ridge and furrow configurations for winter wheat cultivation remain unknown. Here, we evaluated the effects of various ridge-furrow ratios on soil hydrothermal properties, winter wheat growth, yield, resource use efficiency, and profitability under different precipitation years (dry, normal, or wet years) in 2014–2017. A control (CK, conventional flat planting without mulching) and three different ridge-furrow ratios [40:60 (R40), 60:60 (R60), and 80:60 (R80)] were tested. Firstly, PRFRH increased soil water storage and temperature. The soil moisture content assumed a "bell-shaped" distribution which was centered on the planting furrow in the 0−80 cm range. The soil water storage increased with mulched-ridge width, but it will not significantly increase while the mulched-ridge width was too wide. The soil temperature of ridge also increased with mulched-ridge width, whereas the soil temperature decreased in furrow. Moreover, precipitation years had no obvious effect on soil water storage or temperature. Secondly, the dry matter accumulation was captured quite well by the Logistic (R 2 > 0.99). PPRFRH promoted the accumulation of dry matter and increased the winter wheat yield (17.7%), especially in dry year, which mitigated the impact of drought and maintained the yield. Similarly, dry matter accumulation and yield also increased with mulched-ridge width. In contrast, when the ridge was too wide, the effective duration of dry matter accumulation and the yield were reduced. Finally, PRFRH improved the utilization efficiency of water, precipitation and thermal. Nevertheless, the mulched-ridge width required for optimal water-related resource utilization was higher than that needed for optimal thermal utilization. Overall, our results suggest that a 60:60 cm ridge and furrow system can improve dry matter accumulation, crop yield, profitability, and hydrothermal use efficiency in winter wheat grown in the semi-arid regions. [ABSTRACT FROM AUTHOR]

Summary: Considering the effect of many factors on structural behavior, the diagnosing problem on structural behavior of dam engineering is investigated. Dempster–Shafer theory of evidence (DST) and set pair theory (SPT) are combined to fuse the multisource space–time information on dam safety. The structural behavior of dam engineering is identified and its development is forecasted by implementing the information fusions with 3 levels, namely, data fusion, feature fusion, and decision fusion. First, a multisource information fusion system on dam safety is built and an information fusion‐based flowchart is presented to diagnose the dam structural behavior. Second, the batch estimation algorithm is adopted to implement the data fusion on same type information. Third, DST and SPT are applied to the decision fusion on heterogeneous information of dam safety. The index connection number and partial connection number in SPT are introduced to determine the basic probability assignment in DST and identify the dam structural behavior, respectively. Last, one actual dam undergoing structural reinforcements is taken as an example. Its structural behavior is diagnosed, and the reinforcement effect is assessed. It is indicated that the proposed approach is more suitable to be used to evaluate the safety status and reinforcement effect of dangerous dam. [ABSTRACT FROM AUTHOR]

• RFMS improves soil water availability and grain yield under different conditions. • RFMS could regulate hydrothermal conditions during maize growing season. • RFMS with complete coverage is conducive for more limited hydrothermal conditions. • RFMS with ridge coverage is conducive for less limited hydrothermal conditions. The ridge-furrow mulching system with plastic film (RFMS) is considered an effective strategy to improve grain yield and has been widely used in arid and semi-arid rainfed agricultural areas. However, the key mechanism by which RFMS increases yield and efficiency under different hydrothermal conditions remains unclear. Understanding this mechanism and the interaction between different RFMSs and hydrothermal conditions could provide a practical reference for optimizing cultivation. We aimed to investigate the yield increase potential of different planting systems under the same hydrothermal conditions and evaluate the effects of RFMS treatments on drought resistance and yield increase under different hydrothermal conditions. The following planting treatments were carried out in ridge–furrow prepared fields under seven different hydrothermal conditions in a representative rainfed agricultural area for four consecutive years: 1) ridge-furrow mulching system with complete coverage (RC); 2) ridge-furrow mulching system with ridge coverage (RR); and 3) planting without mulching (control treatment; CT). Compared with CT, RFMS improved field hydrothermal conditions and reduced evapotranspiration of crops. In more hydrothermally limited areas (precipitation, 196–320 mm; temperature, <18 °C), the grain yield and water-use efficiency (WUE) with RC significantly increased by 49.95 % and 57.12 % compared with that of CT, respectively. However, RR and RC had no significant difference in grain yield and WUE in areas less hydrothermally limited (precipitation, 320–460 mm; temperature, 18.6 °C–23.6 °C) but increased by 13.51 % and 22.19 % compared with that of CT. Additionally, RFMS improved economic benefits, especially in hydrothermally limited areas, with RC increasing benefits by 142.64 %–200.84 % compared with that of CT. Therefore, RC can be used as the optimal technique to overcome simultaneous drought and cold weather in rainfed agricultural areas under hydrothermally limited conditions. [ABSTRACT FROM AUTHOR]