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Lunar regolith parameters, such as physical temperature, thickness and dielectric constant, are important in studying regolith features, distribution of lunar resources and evolution of the Moon. There had been no measurement obtained by lunar-orbit-borne microwave radiometer applied to evaluate the properties of lunar regolith before CE-1 Lunar Microwave Sounder (CELMS) being launched. CEMLS is the first passive microwave radiometer in the world to sound the surface of the Moon. The brightness temperatures (T B ) sensed by CELMS include complicated information on the above geophysical parameters. In this paper, algorithms of retrieving dielectric constant, regolith thickness, and 3 He content from CELMS brightness temperatures are developed, and the results are compared with those from literature. The results show that the regolith thicknesses are mostly in the range of 4.0-6.0 m, and 43% of them are bigger than 5.0 m. The content of 3 He evaluated by retrieved regolith thickness is about 1.03 million tons. CE-1 Lunar Microwave Sounder (CELMS), lunar regolith, dielectric constant, lunar regolith thickness, 3 He, retrieval Citation:Wang Z Z, Li Y, Jiang J S, et al. Lunar surface dielectric constant, regolith thickness, and 3 He abundance distributions retrieved from the microwave brightness temperatures of

The durability of fiber-reinforced polymer (FRP) composites is significantly dependent on the structures and properties of the resin matrix. In the present paper, the effects of physical or chemical interactions between the molecular chain of the epoxy resin matrix and water molecules or alkaline groups on the water absorption, mechanical structures, and microstructures of epoxy resin samples were studied experimentally. The results showed that the water uptake curves of the epoxy resin immersed in water and an alkali solution over time presented a three-stage variation. At different immersion stages, the water uptake behavior of the resin showed unique characteristics owing to the coupling effects of the solution concentration gradient diffusion, molecular hydrolysis reaction, and molecular segment movement. In comparison with the water immersion, the alkali solution environment promoted the hydrolysis reaction of the epoxy resin molecular chain. After the immersion in water or the alkali solution for one month, the water uptake of the resin was close to saturate, and the viscoelasticity was observed to decrease significantly. The micropore and free volume space on the surface and in the interior of the resin gradually increased, while the original large-scale free volume space decreased. The tensile strength decreased to the lowest point after the immersion in water and the alkali solution for one month, and the decrease percentages at 20 °C and 60 °C water or 60 °C alkali solution were 24%, 28%, and 22%, respectively. Afterward, the tensile strength recovered with the further extension of immersion time. In addition, it can be found that the effect of the alkali solution and water on the tensile strength of the epoxy resin was basically the same.