β?cyclodextrin polymers modified with Fe₃O₄ (β?CDP@Fe₃O₄) was synthesized in alkaline medium using β?cyclodextrin (β?CD) as monomer and epichlorohydrin as crosslinker. The adsorption performances of β?CDP@Fe₃O₄ on bisphenol A (BPA) under static and dynamic conditions were investigated. The results of static experiment show that the adsorption performance of 100 mg/L BPA (pH=5.6) is best at 0.10 g β?CDP@Fe₃O₄. At this point, the equilibrium adsorption capacity, adsorption rate and the maximum adsorption capacity are 45.600 mg/g, 91.3%, and 113.600 mg/g, respectively. The results of dynamic experiment show that the smaller the liquid hourly space velocity, the higher the adsorbent utilization rate, and with the increase of BPA concentration, the adsorption breakthrough time and saturation time are declined. At the same time, the synthesis and adsorption mechanism of β?CDP@Fe₃O₄ were discussed. A rapid adsorption rate for the removal of BPA onto β?CDP@Fe₃O₄ from water solution was achieved, and the adsorption process was mainly due to hydrogen bond and hydrophobic interaction. β?CDP@Fe₃O₄ has good regenerative performance, through 6 cycles of static adsorption?desorption, and 3 cycles of dynamic adsorption?desorption without significant changes in adsorption performance.

The influence of electromagnetic parameters (the distance between upper and lower poles and the coil current intensity) on the flow field in the mold and the volatile behavior of steel/slag interface was studied by numerical simulation. The results show that the magnetic induction intensity in the covered area of the upper magnetic pole and the lower magnetic pole in the full?amplitude two?stage electromagnetic brake crystallizer affects each other. The increase of the current intensity in the coil of the upper (or lower) magnetic pole will lead to the increase of the magnetic induction intensity in the covered area of the corresponding lower magnetic pole (upper magnetic pole). The full amplitude two?stage electromagnetic brake can significantly restrain the flow velocity of molten steel and stabilize the fluctuation of meniscus in the mold. As the distance between upper and lower magnetic poles increases, the impact intensity of molten steel jet on the narrow surface of the mold increases, and the turbulent kinetic energy and velocity of molten steel at the steel/slag interface increase. With the increase of the current intensity of the upper magnetic pole coil, the impact intensity of liquid steel jet on the narrow surface of the mold is basically unchanged, and the flow velocity and turbulent kinetic energy of liquid steel at the steel/slag interface decrease. As the current intensity of the lower pole coil increases, the impact intensity of liquid steel jet on the narrow surface of the mold decreases slightly, and the flow velocity and turbulent kinetic energy at the steel/slag interface decrease.

In order to study the salt precipitation law of the NaCl?Na₂SO₄?H₂O ternary system at a temperature of 298.15 K, the Pitzer model was used to predict and calculate the activity coefficient and solubility of the system, and the variation of the activity coefficients of Na⁺, Cl^- and SO {}_{\mathrm{4}}^{\mathrm{2}-} and the corresponding phase diagram of the ternary system were analyzed. The results show that with the increase of the Na₂SO₄ mass fraction, the activity coefficients of Cl^- and SO {}_{\mathrm{4}}^{\mathrm{2}-} have no obvious change, while the activity coefficient of Na⁺ icreases first and then decreases. When the mass fraction of Na₂SO₄ in the liquid phase is less than 6.8%, the average change rate of the increase in the activity coefficient of Na⁺ is 4.4%. When the mass fraction of Na₂SO₄ in the liquid phase is between 6.8% and 14.9%, the average change rate of decrease in the activity coefficient of Na⁺ is 4.1%, when the mass fraction of Na₂SO₄ in the liquid phase reaches 14.9%, the activity coefficient of Na⁺ decreases fastest, and the average change rate is 8.0%; when the mass fraction of NaCl in the liquid phase is greater than 22.9% and the mass fraction of Na₂SO₄ is less than 6.8% ,as the water evaporates, NaCl precipitates first and Na₂SO₄ precipitates later; when the liquid phase mass fraction of NaCl is 14.0%～22.9% and the mass fraction of Na₂SO₄ is 6.8%～14.9%, the precipitation order is reversed.