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Salinity is a major abiotic stress limiting crop growth and reducing grain yield. In recent years, little progress was made in salt‐tolerant cultivation techniques. Therefore, a controlled experiment was conducted to study the effects of nitrogen management (NM) on growth, antioxidant ability, and yield performance of salt‐tolerant rice (Oryza sativa L.) under salinity stress. Three salinity levels (0‰ as control; 0.75‰, 4.3 dS m−1; and 1.5‰, 7.7 dS m−1) and four levels of NM (tillering fertilizer/panicle initiation fertilizer = 7:3, 6:4, 5:5, and 4:6) were arranged in this study. Under salinity stress, plant height, tiller number, fresh weight, grain yield, panicle, spikelets per panicle, grain weight, and soluble sugar content in stem were significantly decreased. In contrast, antioxidant parameters of superoxide dismutase, peroxidase, and catalase were significantly increased. Grain filling percentage and sucrose content were slightly changed. Compared to the control, grain yield was reduced by 45.6%, 34.8%, 60.4%, and 46.7% at the ratio of 7:3, 6:4, 5:5, and 4:6 NM at 0.75‰ salinity level, and 73.5%, 59.7%, 74.8%, and 61.7% at 1.5‰ salinity level, respectively. The highest yield was generated by 6:4 NM at both the 0.75‰ and 1.5‰ salinity level, and the lowest by 4:6 and 5:5. However, NM could obviously alleviate the inhibition effects of salinity stress and improve antioxidant ability of rice. Among them, 6:4 NM performed the best alleviation effects, followed by 7:3 and 5:5 NM. This study suggests that the appropriate NM can effectively alleviate salinity stress and increase grain yield.

This paper presents an investigation on the effects of intermittent cut-and-fill mining on the overburden failure under sand aquifers. In the intermittent cut-andfilling method, the panel is divided into long pillars, and then entries in every long pillar into a narrow strip; every narrow strip is then cut and backfilled. Field measurements, scale model tests and numerical simulations are used to compare overburden failure and subsidence due to three mining methods: intermittent cut-and-fill mining, longwall excavation and continuous filling. These methods were applied in a case study of the Taiping Coal Mine, in Shandong, China. The results of the numerical simulation and scale model testing reveal that the height of the maximum caving and water-conducting fractured zones, and the maximum subsidence due to intermittent cut-and-fill mining are much smaller than those with the use of longwall excavation and continuous filling and well verified by the field measurements. Additionally, the numerical simulation results of the stress distribution and variation during intermittent cut-and-fill mining are in close agreement with those of the field measurements. It has been proved that the intermittent cut-and-fill mining can successfully mitigate the overburden failure and subsidence, which contribute to preventing water and sand inrush into coal mines under sand aquifers. This provides a less costly and more effective approach to address surface subsidence and mine caving problems.

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The process of research and development on the aero engine is complicate and iterative. Essentially system safety assessment is an indispensable part of the development process. Taking safety assessment of “Extinguishing lapsing when Request” as an example, this paper develops a Monte Carlo calculation model which calculates the probability combination of basic events as the security requirements from top event change. The Monte Carlo model offers a method to calculate from top events request to the basic events.

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