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The overpasses and the terrain under them in Chongqing, a mountainous city in China, are complex and diverse, and some spaces under the overpasses are integrated and reconstructed into the underpass green space for citizens to stroll about or have a rest. From the perspective of visitor perception, this paper constructs a perception evaluation system of the environmental characteristics of underpass green space in mountainous cities from the following five environmental perception dimensions: path organization, security, aesthetic value, physical environment, activities and cultural. The IPA-Kano model is used to quantify environmental perception, and the main environmental factors affecting the improvement of recreation satisfaction of underpass green space in three types of terrain are explored, with a view to improving the environment and service functions of underpass green spaces in high-density interchange networks in mountainous cities, and enhancing the attractiveness of underpass green spaces. It can be found from the study that: (1) Among the five environmental perception dimensions, visitors pay more attention to the physical environment quality of the underpass green space and their physical and psychological activity experience, while their demands for visual senses are relatively low. Due to the deficiency or lack of leisure facilities, sports facilities, children’s playgrounds and amusement equipment, the dimension of “activities and cultural perception” of the underpass green space has the lowest scores of all. (2) The existing sites, facilities and landscape resources of the underpass green space, different terrain types and underpass environment are the important reasons that affect the performance of environmental perception factors and their priority ranking results. (3) The improvement of security of the arrival path or sports facilities is beneficial to improve visitor satisfaction of underpass green space of three types of terrain. The number of environmental factors to be optimized of the three types of terrain are ranked as: mountainous green space > flat green space > concave green space. Among them, four environmental factors have a high priority in two kinds of underpass green space, which are the distribution and quantity of leisure facilities, the effect of noise reduction and sound insulation, the adequacy of activity venues and the distribution and quantity of sports facilities. Finally, according to the particularity of the underpass environment and the characteristics of three types of terrain, this paper puts forward some suggestions for optimizing the service function of underpass green space from five perceptual dimensions.

Cyclic voltammetry (CV) is a powerful and popular electrochemical technique widely used to study the surface structure of materials through the electrochemical behaviors. Herein CV is utilized to study the electrochemical deposition of selenium (Se) on carbon black-supported Pt nanostructures. We synthesized carbon-loaded platinum nanoparticles (Pt/C) by microwave method and studied the electrochemical behavior of selenium on them. Through the experiment of changing the reverse potential, the corresponding relationship between the Se deposition peak and stripping peak was clarified and the deposition and stripping process of Se was proposed. Meanwhile, we synthesized cubic and octahedral nanocrystals of Pt, and used CV to study the Se deposition on these nanosctructures supported by carbon. It was found that the relative intensity of UPD peaks on Pt is different, as Ptcube@C is dominated by (100) and Ptoct@C electrode is dominated by (111) while Pt@C falls in between.

The diffusion-controlled adsorption kinetics of micellar surfactant C12E7 (heptaethylene glycol monododecyl ether) solutions was studied theoretically and experimentally. The corrected diffusion equation, which was used to describe the diffusion of the monomers in the micellar solutions, was solved under the initial and boundary conditions by means of Laplace transformation. The dynamic surface adsorption γ(t) as a function of surface lifetime t, monomer diffusion coefficient D and the demicellization constant was derived. The dynamic surface tensions γ(t) of aqueous submicellar and micellar solutions were measured via maximal bubble pressure method. By analyzing the experimental data, the determined demicellization constant of C12E7 at 25°C was between 100–116 s−1.

For the micellar surfactant solutions, the diffusion equation, in which the effect of the micelles on the monomer diffusion was taken into account, was solved under the initial and boundary conditions by means of Laplace transformation. And a general equation for the dynamic surface adsorption Г(t) as a function of surface lifetime t, critical micelle concentration (cmc), monomer diffusion coefficient D1, and the demicellization constant \( {\overset{\lower0.5em\hbox{$\smash{\scriptscriptstyle\leftarrow}$}}{k}} \) was derived. To determine cmc, the equilibrium surface tensions γeq of aqueous hexaethylene glycol monododecyl ether (C12E6) solutions at temperature 25 °C were measured by means of Wilhelmy plate method and the measured cmc is 8.4 × 10−5 mol 1−1. To study adsorption kinetics, the dynamic surface tensions γ(t) of aqueous submicellar and micellar solutions were measured by means of maximal bubble pressure method and analyzed. Both of the monomers diffusion coefficient D1 and the demicellization constant \( {\overset{\lower0.5em\hbox{$\smash{\scriptscriptstyle\leftarrow}$}}{k}} \) were calculated.

The equilibrium surface tensionsγ eq of aqueous Pentaethylenglycol-monododecylether (C12E5) solutions at temperature 25 °C were measured by means of Wilhelmy plate method and the determined critical micelle concentration (cmc) is 6.8 x 10-2 mol·m-3. To study adsorption kinetics of aqueous submicellar and micellar solutions, the dynamic surface tensionsγ(t) were measured by means of maximal bubble pressure method. Using the derived equations of adsorption kinetics for submicellar and micellar solutions, the experimental data were analyzed and the adsorption kinetics was studied. For micellar solution (c0>cmc) of C12E5, the demicellization constant $$\overset{\lower0.5em\hbox{$\smash{\scriptscriptstyle\leftarrow}$}}{k} $$ was calculated.

The diffusion equation for the expanding surface was solved and a corresponding general expression of dynamic surface adsorption was derived. For the short-time adsorption, a special factor 1/3, which reflected the effect of the expanding surface on the adsorption, appeared in the equation. In addition, the effects of the surface expansion on subsurface concentration (ϕ(t)), dynamic surface adsorption (Γ(t)), dynamic surface tension (γ(t)) and the adsorption mechanism were discussed. In contrast to the adsorption on a still planar surface, ϕ(t) and Γ(t) are smaller, but γ(t) increased. The adsorption mechanism will be the same as long as the corresponding theories are used.

A general dynamic surface adsorption equation Γ(t) for maximum bubble pressure method was derived by solving Fick’s diffusion equation for the bubbles under different initial and boundary conditions. Different from the planar surface adsorption(Ward-Tordai equation), the derived dynamic surface adsorption Γ(t) for the short time consists of two terms, one of them reflects the geometric effect caused by the spherical bubble surface. This kind of effect was discussed. The equilibrium surface tension γeq and the dynamic surface tension γ(t) of aqueous C10E8 (CH3(CH2)9(OCH2CH2)8OH) solution at temperature 25 °C were measured by means of Wilhelmy plate method and maximal bubble pressure method respectively. In the region of t→0 (short time limits) a good agreement of experimental results with the theory was reached and the adsorption was controlled by diffusion. However, for the long time limits, a mixed diffusion-kinetics controlled process was proved.