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[Objective] Water flow and solute transport in soil is important not only for plant acquisition of resources from soil but also for soil and water environment. In terrestrial ecosystems, they are impacted by numerous factors. The objective of this paper is to investigate the effects of drip irrigation amount on spatiotemporal change in water and nitrogen in Hetao Irrigation District, Inner Mongolia. [Method] A field experiment was conducted to measure the movement of water, nitrate and ammonium in soils, with the irrigation amount controlled at 6 mm (D1) or 60 mm (D2). The measured data was used to calibrate the HYDRUS-2D model, and the calibrated model was then used to elucidate how increasing the irrigation amount to 120 mm would affect water and nitrogen movement. [Result] Irrigation increased soil water content in all growth stages. Following irrigation and fertilization, ammonium and nitrate contents both increased rapidly and then decreased. On average, ammonium and nitrate in the 0~10 cm soil layer decreased by 60.0%~62.0% and 40.0%~46.7%, respectively, after the D1 and D2 irrigations, with the decreasing rate varying with growing stage. Compared to D2, D1 increased soil water content at jointing, heading and filling stage by 5.9%, 8.0% and 6.7%, respectively. Soil ammonium and nitrate both decreased along the soil depth. Nitrate accumulation decreased gradually when the crop grew from jointing stage to filling stage. The simulated soil water content and nitrogen agreed well with the measured data. [Conclusion] Experimental data and simulated results showed that irrigating the maize by 120 mm of water can effectively reduce accumulation of nitrate in the 0~60 cm soil layer, and that increasing irrigation frequencies can further curtail nitration accumulation in the 60~100 cm soil layer. These results provide guidance for improving irrigation and fertigation for maize production in Hetao Irrigation District. [ABSTRACT FROM AUTHOR]

Taking the medium deep hole mining in steeply narrow vein of a gold mine in Inner Mongolia as the engineering background, through empirical analogies, numerical simulation and field tests methods, the evolution law of cracks in narrow veins of deep hole blasting under different blasting parameters was analyzed, and the relationship between the blasting parameters and the over-under-excavation percentage of blasting, the density of blasting cracks and the vibration velocity of the surrounding rock particles is obtained. The results show that: when the hole spacing is 1. 2 - 1. 4 m, the over-under-excavation blasting area tends to be zero. When the burdern is 0. 8 - 1. 0 m, the blasting fragmentation is more uniform. A burden of 1. 0 m and a hole spacing of 1. 2 m can be taken as optimal parameters during deep hole blasting. The field blasting test also verifies the research results of this paper. [ABSTRACT FROM AUTHOR]