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Zhu Yuelian’s tomb has been exposed to groundwater for many years, and this exposure has caused many defects, including erosion, encrustation, patina, and spot marks related to groundwater, seriously affecting the artistic and ornamental value of cultural relics. In this study, high-density microelectrode spacing resistivity and ultrasonic transverse wave reflection were used to detect hidden damage in the burial chamber, and the results revealed hidden damage, corrosion, cracks, and pores in the surrounding geological body, concealed cracks in the sidewalls, and internal defects in the columns. An outdoor high-density resistivity test and hydrological observation experiment indicated that the tomb is located in a weakly permeable aquifer, and the groundwater head has been higher than the bottom of the tomb for many years. Natural groundwater flows from northeast to southwest in the aquifer, and the tomb forms an artificial concave cone, causing groundwater around the area to continually flow into the tomb. A chemical composition analysis of the groundwater and scale revealed that the groundwater within the tomb area is slightly corrosive, and the groundwater seepage along the fissures of the compacted layer induces damage. The three-dimensional (3D) seepage numerical simulation results indicated that the combined use of drainage and impervious curtains can cause the water head in the curtain to drop significantly and control the water head to be lower than 8 m from the bottom floor of the tomb, meeting the requirements for seepage prevention and protection of the tomb without long-term maintenance.

Deep learning‐based single view 3D reconstruction is a hot topic in computer vision. However, predicting a more realistic 3D point cloud from a single image is an ill‐posed problem. In recent years, most of the 3D point cloud prediction methods based on single view are straight‐through structure, which will cause the loss of part of feature information and the loss of part of detail information of the resulting point clouds, which will lead to the unsatisfactory visual effect of reconstructed point clouds. In this paper, a Feature‐Enhanced 3D point clouds generation Network (3D‐FENet) from a single image is proposed. In order to enhance the feature information of RGB image, edge extraction module is adopted. In the process of point cloud generation, a point cloud pyramid is designed, which combines low resolution point cloud with high resolution point cloud to enhance the local details of the generated point clouds. In the fine‐tuning stage, the differential projection module is used to fine‐tune the whole network by 2D projection of reconstructed point clouds. Experimental results show that the performance of the authors’ proposed method is better than the state‐of‐the‐art studies.

Oil shale ash(OSA) supported nanoscaled zero-valent iron(OSA-nZVI) was used as a rapid and efficient reductant for Cr(VI) reduction. The optimal mass ratio of nZVI to OSA and the optimal dosage were explored. The effects of initial pH, reaction temperature, initial Cr(VI) concentration, and common cations and anions in ground-water on Cr(VI) reduction were determined in batch experiments. The results show that the optimum initial pH is 5.0. The reaction temperature has a positive effect on Cr(VI) reduction while the real groundwater has a negative effect. Additionally, 84.22% Cr(VI) was still reduced by 3 g/L OSA-nZVI(1:2)(mass ratio of OSA to Fe0was 1:2) within 120 min for 50 mg/L Cr(VI) under conditions of 10 ºC and unadjusted pH.

This paper presents a regenerative cascade inverter topology with direct active power control scheme. From the mathematical model of the proposed regenerative cascade inverter, the instantaneous active power and reactive power are derived. Based on the instantaneous abctheory, direct active power feed-forward control is proposed to reduce AC power and voltage fluctuation in DC link. Moreover, a load current full order observer is established to avoid the inconvenient of the current sensor installation. The proposed control scheme is analyzed theoretically by simulation, and verified experimentally.

The four-element infrared detecting system is a common used detecting system to detect a target from sky background. However, one of the main application limits of this system is the short detecting distance. Consequently, this paper presents an adaptive weak signal extraction algorithm, with which the weak distant target signal can be extracted, thus the detecting distance can be obviously lengthened.