Permanently shadowed regions(PSRs)on the Moon are potential reservoirs for water ice,making them hot spots for future lunar exploration.The water ice in PSRs would cause distinctive changes in space weathering there,i...Permanently shadowed regions(PSRs)on the Moon are potential reservoirs for water ice,making them hot spots for future lunar exploration.The water ice in PSRs would cause distinctive changes in space weathering there,in particular reduction-oxidation processes that diff er from those in illuminated regions.To determine the characteristics of products formed during space weathering in PSRs,the lunar meteorite NWA 10203 with artifi cially added water was irradiated with a nanosecond laser to simulate a micro-meteorite bombardment of lunar soil containing water ice.The TEM results of the water-incorporated sample showed distinct amorphous rims that exhibited irregular thickness,poor stratifi cation,the appearance of bubbles,and a reduced number of npFe^(0).Additionally,EELS analysis showed the presence of ferric iron at the rim of the nanophase metallic iron particles(npFe^(0))in the amorphous rim with the involvement of water.The results suggest that water ice is another possible factor contributing to oxidation during micrometeorite bombardment on the lunar surface.In addition,it off ers a reference for a new space weathering model that incorporates water in PSRs,which could be widespread on asteroids with volatiles.展开更多
This study proposes a multi-scene smoke detection algorithm based on a multi-feature extraction method to address the problems of varying smoke shapes in different scenes,difficulty in locating and detecting transluce...This study proposes a multi-scene smoke detection algorithm based on a multi-feature extraction method to address the problems of varying smoke shapes in different scenes,difficulty in locating and detecting translucent smoke,and variable smoke scales.First,the convolution module of feature extraction in YOLOv5s backbone network is replaced with asymmetric convolution block re-parameterization convolution to improve the detection of different shapes of smoke.Then,coordinate attention mechanism is introduced in the deeper layer of the backbone network to further improve the localization of translucent smoke.Finally,the detection of smoke at different scales is further improved by using the feature pyramid convolution module instead of the standard convolution module of the feature pyramid in the model.The experimental results demonstrate the feasibility and superiority of the proposed model for multi-scene smoke detection.展开更多
This paper analyzes the morphological characteristics and mineralogy of drilled basaltic clast sample CE5Z0806YJYX004, compares the variations in Chang'e-5 samples at different depths, and conducts a comparative a...This paper analyzes the morphological characteristics and mineralogy of drilled basaltic clast sample CE5Z0806YJYX004, compares the variations in Chang'e-5 samples at different depths, and conducts a comparative analysis with surface-collected samples from Chang'e-5 and Apollo missions. Interestingly, Advanced electron microscopy identified bubbles and microcracks on the surface of some constituting mineral particles, and also displays crystalline particles with distinct rock textures and spherical droplets, revealing surface phenomena formed by space weathering. Based on Raman spectroscopy analysis, the main mineral phases were identified as 49.6 vol% pyroxene, 31.4 vol% plagioclase and 8.8 vol% olivine. Apatite, ilmenite and cristobalite are also found. The results indicate that the Chang'e-5 lunar soil exhibits similar mineral compositions at different depths. In short, a comparison was made between our drilling sample and the Chang'e-5 soil samples as well as samples from the Apollo mission series, demonstrating the physical similarities and some variations.展开更多
基金support from the Youth Innovation Promotion Association,Chinese Academy of Sciences(2020395)Strategic Priority Research Program of the Chinese Academy of Sciences grant XDB 41000000(Y.L.)+4 种基金National Natural Science Foundation of China(Nos.42273042 and 41931077)"From 0 to 1"Original Exploration Cultivation Project,Institute of Geochemistry,Chinese Academy of Sciences(DHSZZ2023-3)Guizhou Provincial Foundation for Excellent Scholars Program(No.GCC[2023]088)Guizhou Provincial Science and Technology Projects:QKHJCZK[2023]-General 473NSFC Young Scientist Fund(Nos.42303041 and 42403043)。
文摘Permanently shadowed regions(PSRs)on the Moon are potential reservoirs for water ice,making them hot spots for future lunar exploration.The water ice in PSRs would cause distinctive changes in space weathering there,in particular reduction-oxidation processes that diff er from those in illuminated regions.To determine the characteristics of products formed during space weathering in PSRs,the lunar meteorite NWA 10203 with artifi cially added water was irradiated with a nanosecond laser to simulate a micro-meteorite bombardment of lunar soil containing water ice.The TEM results of the water-incorporated sample showed distinct amorphous rims that exhibited irregular thickness,poor stratifi cation,the appearance of bubbles,and a reduced number of npFe^(0).Additionally,EELS analysis showed the presence of ferric iron at the rim of the nanophase metallic iron particles(npFe^(0))in the amorphous rim with the involvement of water.The results suggest that water ice is another possible factor contributing to oxidation during micrometeorite bombardment on the lunar surface.In addition,it off ers a reference for a new space weathering model that incorporates water in PSRs,which could be widespread on asteroids with volatiles.
基金the Natural Science Foundation of Zhejiang Province(Nos.LY20F020015 and LY21F020015)the National Natural Science Foundation of China(Nos.61972121 and 61902099)。
文摘This study proposes a multi-scene smoke detection algorithm based on a multi-feature extraction method to address the problems of varying smoke shapes in different scenes,difficulty in locating and detecting translucent smoke,and variable smoke scales.First,the convolution module of feature extraction in YOLOv5s backbone network is replaced with asymmetric convolution block re-parameterization convolution to improve the detection of different shapes of smoke.Then,coordinate attention mechanism is introduced in the deeper layer of the backbone network to further improve the localization of translucent smoke.Finally,the detection of smoke at different scales is further improved by using the feature pyramid convolution module instead of the standard convolution module of the feature pyramid in the model.The experimental results demonstrate the feasibility and superiority of the proposed model for multi-scene smoke detection.
基金supported by the National Natural Science Foundation of China (grant No. 52075217, 52475019)。
文摘This paper analyzes the morphological characteristics and mineralogy of drilled basaltic clast sample CE5Z0806YJYX004, compares the variations in Chang'e-5 samples at different depths, and conducts a comparative analysis with surface-collected samples from Chang'e-5 and Apollo missions. Interestingly, Advanced electron microscopy identified bubbles and microcracks on the surface of some constituting mineral particles, and also displays crystalline particles with distinct rock textures and spherical droplets, revealing surface phenomena formed by space weathering. Based on Raman spectroscopy analysis, the main mineral phases were identified as 49.6 vol% pyroxene, 31.4 vol% plagioclase and 8.8 vol% olivine. Apatite, ilmenite and cristobalite are also found. The results indicate that the Chang'e-5 lunar soil exhibits similar mineral compositions at different depths. In short, a comparison was made between our drilling sample and the Chang'e-5 soil samples as well as samples from the Apollo mission series, demonstrating the physical similarities and some variations.
