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In arid and semi-arid regions, plastic film mulching can effectively improve crop yield, but with the increase of service life, a lot of residual plastic film (RPF) remains in the soil. The application of a RPF to a soil will alter soil moisture processes, and thus, affect the soil water distribution and its effectiveness. A quadratic regression orthogonal design was used to study the effects of initial moisture content (IMC), dry bulk density (DBD), residual plastic film content (RPFC), and the burial depth of RPF on the migration time of wetting front (MF), moisture content (MC), and accumulative infiltration (AI) of a test soil. It was found that IMC, DBD, and RPFC were the main factors affecting MC, MF, and AI, while the burial depth of RPF had no significant influence. The order of influence for the factors affecting MF was IMC &gt, DBD &gt, RPFC, while the order of influence for the factors affecting MC and AI was DBD &gt, IMC &gt, RPFC. RPFC was parabolic in relation to MF, MC, and AI, when it was in the range of 50&ndash, 100 kg/hm2, while within the same range MC and AI reached a maximum and MF reached a minimum. The analysis of the interactive responses revealed that when the DBD was greater than 1.29g/cm3, the MF initially decreased and then increased with the increase of RPFC. When the RPFC was more than 100 kg/hm2, the MF initially increased and then decreased with the increase of the DBD. When the DBD was larger than 1.31 g/cm3, the AI initially increased and then decreased with the increase of RPFC. It was apparent that the RPF not only had a blocking effect on the wetting front, but also affected the water flow. When the RPFC was between 50 and 100 kg/hm2, the soil MC was significantly increased. It was suggested that the RPF pollution area should increase the mechanical recovery of plastic film, standardize the use and recycling of agricultural RPF, optimize the planting model, and establish a recyclable model for the treatment of RPF pollution, and it was proposed that the RPFC remaining after recovery of the RPF should be less than 50 kg/hm2.This study can prove the law of soil water movement in the residue film pollution area and provide reference and solution ideas for the comprehensive treatment of residue film pollution in farmland.

The current miniaturization trend of microelectronic devices drives the size of solder joints to continually scale down. The miniaturized joints considerably increase intermetallic compounds (IMCs) volume fraction to trigger mechanical reliability issues. This study investigated precise relationships between varying IMC volumes and mechanical properties of Ni/Sn(20&mu, m)/Ni micro-joints. A designed method that followed the IMC volume as the only variable was used to prepare micro-joint samples with different IMC volumes. The continuously thickened Ni3Sn4 IMCs exhibited a noticeable morphology evolution from rod-like to chunky shape. The subsequent tensile tests showed unexpected tensile strength responses as increasing Ni3Sn4 volume, which was strongly associated with the Ni3Sn4 morphological evolutions. Fractographic analysis displayed that the ductile fracture dominates the 20%&ndash, 40% IMC micro-joints, whereas the brittle fracture governs the 40%&ndash, 80% IMC micro-joints. For the ductile fracture-dominated joints, an abnormal reduction in strength occurred as increasing IMCs volume from 20% to 40%. This is primarily due to severe stress concentrations caused by the transformed long rod-typed morphology of the Ni3Sn4. For the brittle fracture-dominated joints, the strength appeared a monotonous increase as the Ni3Sn4 volume increased. This may be attributed to the increased crack resistance resulting from continuous coarsening of the chunky Ni3Sn4 without any voids. Moreover, the finite element analysis was provided to further understand the joint failure mechanisms.