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Context. The surface composition of the Moon has mainly determined based on the visible and near-infrared spectra achieved from orbits and/or landing sites, and the spectroscopic analysis is based on photometric properties of the topmost lunar regolith. However, the lack of a ground truth for the photometric parameters of the undisturbed lunar surface has limited accurate applications of spectral observations. Aims. Here we report the photometric properties of the small-scale (i.e., centimeter level) undisturbed lunar regolith around the Chang’E-4 landing site, determined from a series of photometric experiments conducted by the rover Yutu-2. Methods. The simplified Hapke model was used to derive the photometric properties. The micro-topographic effect on the spectral measurements was corrected for the first time in the in situ photometric investigations on the Moon, which improves the accuracy of the derived photometric parameters. Results. The single-scattering albedo w and two parameters (b, c) of the Henyey-Greenstein phase function were derived, and they show a wavelength dependence. The regolith at the Chang’E-4 landing site exhibits strong forward scattering according to the retrieved c values, and the higher asymmetry parameter indicates that the regolith here is more strongly forward scattering than the Apollo lunar soil samples. The derived photometric parameters can serve as ground truth and can be used in the radiative transfer modeling analysis of the orbital remote-sensing data.

The Yutu‐2 rover of the Chang'E‐4 spacecraft observed many meter‐sized shallow pits fully covered with small fragments, distinct from the typical rock‐free impact craters with comparable sizes in the landing area. The unique morphology of the pits and the visible and near‐infrared spectra of the fragments suggest that the fragments are broken pieces of impact melt‐conglutinated regolith breccia projectiles, which were excavated from preexisting craters. The rareness of rock on the landing area surface suggests that the preexisting craters were probably small in size (e.g., <60 m in diameter), not large enough to penetrate the thick regolith (~12 m) and to excavate the beneath rock breccia and/or bedrock. The presence of the impact melts was confirmed by the glass‐like spectra of some fragments with unusually high albedo and blue‐green tint in the centers of the pits. These observations reveal the gardening and consolidating processes on the Moon.

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The specific input energy (SIE), current density, and discharge power of homemade strong ionization dielectric barrier discharge (DBD) were studied to suppress gas-phase benzene at atmospheric pressure efficiently. Findings indicate that for 300 ppm of benzene at 3.5 kJ/L SIE, benzene's removal efficiency reached 96%. The decline in current density by 66.48% and 43.7% for an initial benzene concentration of 300 ppm was due to increased oxygen content (from 2.4% to 20.9%) and relative humidity (from 18.9% to 90%), respectively, thus reducing electron concentration and consequentially enhanced the removal efficiency over 93%.Furthermore, the decomposition law's beta parameter decreased from 3.1 kJ/L at 300 ppm to 1.6 kJ/L at 100 ppm, indicating that •O and •OH radicals are key species for the decomposition of benzene and electron dissociation reactions largely control the process. The Maxwell– Boltzmann electron energy distribution function was solved using the average energy of the strong ionization discharge reactor (~10 eV), showing that approximately 84.8 % of high energy electrons possess enough energy to cause the benzene ring cleavage and free radical production. The study results show that the strong ionization DBD plasma reactor is highly efficient in removing benzene from industrial waste air, hence air pollution control.