Enhancement of ionospheric heating effect by chemical release.

The ionosphere can be artificially modified by employing ground-based high-power high-frequency electromagnetic waves to irradiate the ionosphere. This modification is achieved through the nonlinear interaction between the electromagnetic waves and the ionospheric plasma, leading to changes in the physical properties and structure of the ionosphere. The degree of artificial modification of the ionosphere is closely related to the heating energy density of high-frequency pump waves. Due to the high density of neutral constituents in the lower ionosphere and the high frequency of electron-neutral collisions, the energy of heating pump waves will be absorbed and attenuated during the penetration of the low ionosphere, seriously affecting the heating effect. This paper proposes a method to reduce the absorption of ionospheric heating pump waves by releasing electron attachment chemicals into low ionosphere to form a large-scale electron density hole. A model for mitigating pump waves absorption based on SF6 release is established, and the absorption at different frequencies is quantitatively calculated. The propagation characteristics of high-frequency signals in ionospheric holes are studied using a three-dimensional ray tracing method, and the results demonstrate that the chemical release method not only reduces the absorption attenuation of heating pump waves but also forms spherical electron density holes, which exhibit a focusing effect on the heating beam and enhance the heating effect. The results are of great significance for understanding the nonlinear interaction between electromagnetic wave and ionospheric plasma and improving the ionospheric heating efficiency.

[Fabrication of a Biomass-Based Hydrous Zirconium Oxide Nanocomposite for Advanced Phosphate Removal].

Wheat straws were modified by 3-chloro-2-hydroxypropyl trimethylammonium chloride (CTA) to obtain aminated wheat straw St-N'. The optimum synthetic conditions were determined to be NaOH with 30% mass fraction, CTA of 100 mL, reaction temperature of 80℃, and reaction time of 3 h, which was verified by orthogonal experiments. Nano-sized hydrous zirconium oxides (HZO) were immobilized into St-N' by an in situ precipitation method to obtain the nanocomposite St-N'-Zr. The SEM, TEM, XRD, and BET results indicated that the nano-sized HZO with 50-100 nm sizes were uniformly loaded onto the inner surface of the biomass-based carrier St-N' that was amorphous in nature. A Langmuir adsorption isotherm fitted the adsorption process well, and the maximum adsorption amount was calculated to be 33.90 mg·g-1. The optimal pH range was 1.8-6.0, displaying good removal capacity of phosphate in acidic waters. In the presence of high levels of competing anions, the phosphate adsorption still retained more than 70% of the original amount, showing the higher preference of St-N'-Zr towards phosphate than towards the commercial anion exchanger D-201. After 10 cycles of adsorption-desorption, the removal efficiency remained stable, confirming the good regeneration ability and potential application of St-N'-Zr.

Enhancement on the Surface Hydrophobicity and Oleophobicity of an Organosilicon Film by Conformity Deposition and Surface Fluorination Etching.

In this work, the surface morphology of a hydrophobic organosilicon film was modified as it was deposited onto a silver seed layer with nanoparticles. The surface hydrophobicity evaluated by the water contact angle was significantly increased from 100° to 128° originating from the surface of the organosilicon film becoming roughened, and was deeply relevant to the Ag seed layer conform deposition. In addition, the organosilicon film became surface oleophobic and the surface hydrophobicity was improved due to the formation of the inactive C-F chemical on the surface after the carbon tetrafluoride glow discharge etching. The surface hydrophobicity and oleophobicity of the organosilicon film could be further optimized with water and oleic contact angles of about 138° and 61°, respectively, after an adequate fluorination etching.

[Sorption of o-Phthalate onto Calcite in Open-System].

The batch sorption methods were deployed to study the sorpti of p-phthalate on calcite in open-system. Results show that: (1) The o-phthalate sorption reached the equilibrium within 3 hours. Both pseudo first-order and pseudo second-order models described the kinetic characteristics well; (2) The o-phthalate sorption rate decreased with pH (7. 7-9.7). This phenomenon was due to the competition effect of HCO3- and CO(3)2-, and the electrostatic effect on the surface; (3) The o-phthalate sorption rate also decreased with the increase in ionic strength. This was due to the rise in concentration of HCO3- and CO(3)2- induced by salt effect; (4) Compared with m-phthalate and p-phthalate, o-phthalate sorption rate was much higher due to the proximity of its two carboxyl groups which easily formed a chelate ring of surface complex. By studying the factors that influence o-phthalate sorption onto calcite, the sorption mechanism can be well understood. This mechanism can be applied in the removal of o-phthalate from the environment.

[Removal of Phosphate by Calcite in Open-System].

Batch methods were deployed to study the removal of phosphate by calcite in an open-system. Results showed that: (1) The pre-equilibrium process of calcite in open system could be achieved within 24 hours (2) The kinetic results showed that, at initial concentration of 0.5 mg · L⁻¹, the phosphate removal was almost completed within 10 hours of the first phase. The observation may be attributed to surface adsorption. At initial concentration of 2.5 mg · L⁻¹, the phosphate removal was mainly carried out by the precipitation of phosphate at later stage of the process; (3) At initial concentration of ≤ 2.5 mg · L⁻¹ setting 10 h as reaction time, the phosphate removal process was described well by the Langmuir model. It is hypothesized that surface adsorption was the principal removal way of phosphate; (4) With the addition of phthalate, at initial concentration of < 2.5 mg · L⁻¹, the phosphate removal rate experienced a small decrease. That was because phosphate was mainly removed by surface adsorption, and thus, phthalate was a competitor to phosphate for the same adsorption site. The phosphate removal rate increased a little at initial concentration of > 2.5 mg · L⁻¹, this was because the phosphate precipitation was reinforced by the increase of calcium concentration, which was caused by phthalate addition.