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In this study, taking a certain iron ore tailings pond as the research object, a closed pond engineering design was conducted to ensure its sustained and stable operation. Firstly, installation of a flood drainage system (spillway) and closure of the existing overflow tower and drainage pipe are suggested. Secondly, numerical analysis is conducted on the seepage field of the dam body to determine the position of the saturation line of the dam body under normal water storage level and design flood level. Subsequently, the stability of the dam body under various working conditions is assessed using the limit equilibrium method.

One-step metal-assisted chemical etching (MACE) was used to fabricate porous silicon nanowire arrays. Also, the effects of doping level, AgNO3 concentration, and HF concentration on the morphology and structure of porous silicon nanowire were investigated. The results show that the higher doping level is beneficial for etching the silicon wafer and forming silicon nanowire arrays. This is because the higher doping level introduces more impurities and defects on the surface of the silicon wafer, and at the same time, the Schottky barrier between the silicon wafer with the higher doping level and the solution is lower. Thus, the silicon wafer is easier to oxidate to form nanowire arrays. The AgNO3 concentration plays a critical role in the fabrication of the porous silicon nanowire arrays during the one-step MACE process. If AgNO3 concentration is too low or too high, corrosion pits and collapsed clusters of nanowires could form on the surface of the silicon wafer. When AgNO3 concentration was 0.02 mol·L-1, silicon nanowires grew and became longer, eventually forming a porous array of silicon nanowire. In the meantime, as silicon nanowires grew, capillary stress between nanowires caused agglomeration at the top of some nanowires. Furthermore, when HF solution concentration exceeded 4.6 mol·L-1, the length of silicon nanowire increased with increasing HF concentration. Furthermore, a porous structure was formed on top the silicon nanowire, and the porosity of the silicon nanowires increased with increasing HF concentration. This was due to a large number of Ag+ random nucleations at the top of the nanowires, and lateral etching of the silicon nanowires occurred. In the end, the formation process of the porous silicon nanowires is explained by a model based on the experimental phenomena. It is attributed to the deposition of silver ions and the oxidation of dissolved silicon substrates.

The feasibility and mechanisms of using the blast furnace dust as a reductant in direct reduction-low intensity magnetic separation of Indonesian seaside titanomagnetite were investigated. The results show that the blast furnace dust can be used as an alternative to coal as a reductant under the condition of fluorite as an additive. Under the synergistic effect of the blast furnace dust and fluorite,the recovery and grade of iron in the reduction iron powder can be increased and the content of TiO2 can be decreased at the same time during the direct reduction process. Simultaneously,iron in the blast furnace dust can also be recovered. A comparison of three different kinds of blast furnace dusts indicates that the composition of the blast furnace dust can influence the effect of reduction.Under the same dust dosage,the Jinxin blast furnace dust(referred to as JX) show the best reduction performances. The optimum conditions of roasting reduction are the blast furnace dust dosage of 30%,the fluorite dosage of 10% and reduction at 1250℃ for 60 min. The reduction iron powder,with 91.28% Fe grade,0.93% TiO2 content and 89.19% total iron recovery including iron in the run-of-mine and blast furnace dust,is obtained after the roasted product is processed by using a process of two-staged grinding and two-staged magnetic separation.

Abstract Background B7-H3 is an important immune checkpoint molecule that plays a negative role in immune regulation. This study was aimed to explore B7-H3 expression in HIV-infected patients and its clinical significance. Methods To explore the expression and clinical significance of B7-H3 in HIV-infected patients, we investigated the B7-H3 expression pattern and the correlation of B7-H3 expression with clinical parameters of HIV-infected patients with different levels of CD4+ T cells. To assess the role of B7-H3 in regulating the function of T cells in HIV infection, we performed a proliferation assay and T cell function test in vitro. Results B7-H3 expression in HIV-infected patients was significantly higher than that in healthy controls. mB7-H3 expression on CD4+CD25high T cells and CD14+ monocytes increased with disease progression. mB7-H3 expression on CD4+CD25high T cells and monocytes was negatively correlated with lymphocyte count, CD4+T cell count, and positively correlated with HIV viral load in HIV-infected patients. when the number of CD4+ T cells in HIV-infected patients was ≥ 200/µL, sB7-H3 and mB7-H3 expression levels on CD4+CD25high T cells and monocytes were negatively correlated with lymphocyte count, CD4+T cell count. sB7-H3 and mB7-H3 expression on monocytes were positively correlated with HIV viral load. B7-H3 inhibited the proliferation of lymphocytes and the secretion of IFN-γ in vitro, especially the ability of CD8+ T cells to secrete IFN-γ. Conclusions B7-H3 played an important negative regulatory role in anti-HIV infection immunity. It could be used as a potential biomarker for the progression of HIV infection and a novel target for the treatment of HIV infection.