Cement is widely used in marine concrete, and its resistance to chloride ion corrosion has been widely considered. In this paper, based on a laboratory test, the influence of different hydrostatic pressures, coarse aggregate contents and w/c ratios on the chloride resistance performance is analyzed. Based on COMSOL finite element software, a two-dimensional cementitious materials model is established, and the simulation results are compared with the experimental results. The results show that the penetration depth of chloride ions in cement increases with the increase of the w/c ratio. Under the hydrostatic pressure of 0 MPa, when the w/c ratio is 0.35, the penetration depth of chloride ions is 7.4 mm, and the simulation result is 8.0 mm. When the w/c ratio is 0.45, the penetration depth of chloride ions is 9.3 mm, and the simulation result is 9.9 mm. When the w/c ratio is 0.55, the penetration depth of chloride ions is 12.9 mm, and the simulation result is 12.1 mm. Under different hydrostatic pressures, the penetration depth of chloride ions obviously changes, and with the increase in hydrostatic pressure, the penetration depth of chloride ions deepens. Under the w/c ratio of 0.35, when the hydrostatic pressure is 0.5 MPa, the penetration depth of chloride ions is 11.3 mm, and the simulation result is 12.1 mm. When the hydrostatic pressure is 1.0 MPa, the penetration depth of chloride ions is 16.2 mm, and the simulation result is 17.5 mm.

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In this paper,author use electroflocculationt to deal with heavy metal lead and zinc smelting wastewater,disiscussing the impact of electroflocculation to heavy metal removal rate under different pH,electrolytic voltage,electrolysis time ,plate spacing conditions. The results show that: heavy metal removal rate achieve the best effects when the situationgs is that pH is 11, electrolysis voltage is 2v, electrolysis time is 30 min , plate spacing is 1.2cm.Cd removal efficiency is 100% ,99.92 % removal efficiency of Zn,95.53% removal efficiency of Pb and 98.64% removal efficiency of Cu

In response to the green energy-saving goal of carbon neutralization and carbon peak, the research and development of green building materials have become a key research direction. Desulfurization gypsum is widely used in building materials because of its good energy saving, but it cannot be used in high humidity areas because of its highly soluble salt. Based on this reason, this paper uses statistically designed experiments (SDE) to design the experiments on the influence of four common soluble salt ions 〖Na〗^+ 、〖Mg〗^(2+) 、〖Cl〗^- and K^+ on the sagging deformation of desulfurization gypsum, and studies the significance of their influence by SDE experimental analysis method. The results show that: (1) in the environment of a single salt solution, K^+ ion, 〖Mg〗^(2+) ion, 〖Na〗^+ ion, and 〖Cl〗^- ion will cause sagging deformation of desulfurization gypsum, and their values are 0.432mm, 1.933mm, 0.942mm, and 0.940mm respectively. It can be seen that the effect of the 〖Mg〗^(2+) ion is the most significant. (2) In the environment of composite salt solution, K^+ ions will inhibit the sagging deformation of desulfurization gypsum. Specifically, in the compound salt solution environment of K^++〖Mg〗^(2+) and K^++〖Na〗^+, the deformation values are 0.605mm and 0.596mm respectively.

In view of the special requirements of rails to ensure the safe and stable operation of Railways in China, the formation characteristics of austenite grains in high carbon rail are revealed through industrial exploration, the process of industrial rail heating and rolling is simulated, innovative experimental research methods such as different heating and heat treatment are carried out on the actual rails in the laboratory. Transfer characteristics of austenite grain size, microstructures and key properties of high carbon rail during the process are also revealed. The results show that the austenite grain size of industrial produced U75V rail is about 9.0 grade. When the holding temperature is increased from 800 C to 1300 C, the austenite grain size of high carbon rail steel decreases, the austenite grain are gradually coarsened, and the tensile strength increases slightly. The tensile strength is affected by the heating temperature. With the increase of heating temperature, the elongation and impact toughness of high carbon rail decrease. The heating temperature of high carbon rail combined with austenite grain size shows that the heating temperature has a great influence on austenite grain size, and has the most obvious influence on the toughness of high carbon rail.