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Comprehensive Detection Payload Technology for Space Environment of FY-3E Satellite
SHEN Guohong, HUANG Cong, ZHANG Pengfei, ZHANG Xiaoxin, WANG Jinhua, LI Jiawei, ZONG Weiguo, ZHANG Shenyi, ZHANG Xianguo, SUN Yueqiang, YANG Yong, ZHANG Huanxin, ZOU Hong, WANG Jindong, SUN Ying, BAI Chaoping, TIAN Zheng
Acta Scientiarum Naturalium Universitatis Pekinensis    2024, 60 (1): 145-156.   DOI: 10.13209/j.0479-8023.2023.096
Abstract （71）   HTML    PDF（pc） （19964KB）（46）       Save
To monitor the space environment and its effects in the low-Earth sun-synchronous orbit of China’s FY-3 satellite, a comprehensive detection technology based on the type Ⅱ loads of the space environment monitor is proposed. In the process of ground development, various technical indicators of the space environment comprehensive detection payload have been calibrated and experimentally verified by different methods such as standard radiation source, equivalent signal source, particle accelerator and standard magnetic field. The results show that the multi-direction full-spectrum particle detection achieves an energy range of 30 keV–300 MeV, with the accuracy of ≤10%. The magnetic field detection realizes the measurement range of −65023–+65023 nT, with the accuracy of ≤0.73 nT. The potential detection realizes the measurement range of −32.4–+23.7 kV, with the sensitivity of ≤10V. The detection of radiation dose realizes the measurement range of 0–3×104 rad (Si), with the sensitivity of ≤8.3 rad (Si). Through comprehensive observation of particle radiation environment, change of in-situ magnetic field vector, radiation dose accumulation and change of satellite surface potential in satellite operation orbit, the space environment monitor provides necessary data support for space activities, satellite design, space science research and space weather early warning and prediction. 
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Study on Filtration Efficiency of Facemask for Atmospheric Particulate Matter in Real Environment
JIANG Meijie, ZHANG Peng, GONG Jicheng
Acta Scientiarum Naturalium Universitatis Pekinensis    2022, 58 (2): 354-360.   DOI: 10.13209/j.0479-8023.2021.117
Abstract （447）   HTML    PDF（pc） （2837KB）（50）       Save
Five kinds of respirators were selected to analyze the protective performance of four kinds of atmospheric particulate matter in the real environment of Beijing with different pollution levels, and the effects of particle, respirator types, inspiratory flow rate and atmospheric PM2.5 concentration on the protective performance of respirators were studied. The results showed that the four factors had significant effects on the protective performance of the facemasks. The particle protective performance of facemasks increased with the increase of particle size. The protective performance of four types of KN95 or KN90 facemasks for actual atmospheric particles could reach 80%, while the protective performance of disposable medical surgical facemasks was far lower than the above four types. The inspiratory flow also significantly affected the protective performance of the facemask, possibly due to the difference in filter material performance and leakage rate at different flow rates. The influence of atmospheric PM2.5 concentration on the protective performance of different facemasks was complex 
and there was not a simple correlation.
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Origin of Cherts during the Ediacaran-Cambrian Transition in Hunan and Guizhou Provinces, China: Evidences from REE and Ge/Si
WEI Shuaichao, CHEN Qifei, FU Yong, CUI Tao, LIANG Houpeng, GE Zhihua, ZHANG Peng, ZHANG Yong
Acta Scientiarum Naturalium Universitatis Pekinensis    2018, 54 (5): 1010-1020.   DOI: 10.13209/j.0479-8023.2018.035
Abstract （799）   HTML    PDF（pc） （5222KB）（138）       Save

Two types of Liuchapo Formation cherts, bedded cherts and mounded cherts, were deposited in Bahuang section of Tongren in Guizhou Province and Ganziping section of Zhangjiajie in Hunan Province. The origin of the cherts was discussed by analyzing the characteristics of major, trace elements and REE compositions and Ge/Si ratios. It was revealed that the content of SiO2 in bedded cherts was range from 96.06% to 99.61%, and the content of SiO2 in mounded cherts was range from 98.62% to 99.56%, averaging 99.13%, and the contents of other chemical components were very low. Thus, two types of cherts are pure cherts. Moreover, the ΣREE of the bedded cherts in Bahuang section is ranged from 20.14 to 248.56 μg/g (averaging 100.62 μg/g), and no obvious abnormality in Eu/Eu* which is ranged from 0.90 to 1.10 (averaging 1.06), and the ratio of Ge/Si is 0.13−0.98 μmol/mol (averaging is 0.50 μmol/mol), indicating that the origin of bedded cherts affected terrigenous input. Whereas, the ΣREE of the mounded cherts in Ganziping district is ranged from 3.75 to 7.24 μg/g (averaging 5.73 μg/g), the ratio of Ce/Ce* is 0.46−0.66 (averaging 0.57) which shows a negative abnormal, Eu/Eu* is ranged from 2.28 to 11.07 (averaging 4.60) which shows a positive abnormal, and Ge/Si ratio is 1.09−1.43 μmol/mol, (averaging 1.25 μmol/mol) all of which reflect a hydrothermal origin of the mounded cherts. Otherwise, the relationship between Al2O3 and ΣREE in the bedded cherts has an excellent correlation, while in the mounded cherts has a poor correlation. It also illustrates that continental substance plays an important role in controlling the formation of bedded cherts, and the mounded cherts is originated from submarine volcanic or hydrothermal activity. The relationship between Al2O3 and Ge/Si also reflect the origin of cherts. Combined with the paleogeographic environment, it can conclude that the mounded cherts were deposited in syngenetic fault at the margin of the basin, originated from submarine hydrothermal activity, while the bedded cherts were deposit in the deep basin, mainly influenced by terrigenous input. What’s more, using 1 μmol/mol as the critical value of Ge/Si may provide a new way to trace the material sources of cherts.

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Structural Stress Field Simulation for Upper-Middle-Lower Cambrian in Tazhong Area and Forecast of the Fracture
ZHANG Peng;HOU Guiting;PAN Wenqing;QI Yingmin
Acta Scientiarum Naturalium Universitatis Pekinensis    DOI: 10.13209/j.0479-8023.2014.178
Research on the Effectiveness of Fractures in Sinian-Cambrian Dolomite Reservoir in Tarim Basin
ZHANG Peng,HOU Guiting,PAN Wenqing,QI Yingmin,Chen Yongquan,ZHANG Qinglian,MENG Qingfeng
Acta Scientiarum Naturalium Universitatis Pekinensis   
Abstract （702）      PDF（pc） （4477KB）（269）       Save
Combining the core observation and related logging data of the drillings in Sinian-Cambrain stratum, the dolomite reservoir section fractures were studied. It shows that fractures have a connected effect on native holes and some secondary holes, and plays a certain role in the transformation of the dolomite reservoir. After studying the relation between the fracture efficiency and fracture opening degree or fracture dip angle in four blocks of the Tarim Basin, Tazhong Area,Yaha Area, Yingmaili Area, and Bachu area, it is concluded that dolomite fractures which have narrower opening degree and higher angle have a higher effectiveness, and such kind of fractures play an important role in the transformation of dolomite reservoir.
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Effect of Carbonate Rock to Development of Structural Fracture in the Area of Keping, Xinjiang, China
ZHANG Peng,HOU Guiting,PAN Wenqing,JU Yan,ZHANG Qinglian,LI Le,SHU Wulin
Acta Scientiarum Naturalium Universitatis Pekinensis   
Abstract （604）      PDF（pc） （2564KB）（442）       Save
Four sections of dolomite, grainstone, micritic limestone and granulir micritic limestone in Dawangou of Keping area are selected, and their structural fractures are statistically analyzed. The results of fracture density measurements show that the value of the fracture density from big to small is dolomite, grainstone, micritic limestone and granulir micritic limestone, which means in the same tectonic setting dolomite is easier to produce structural fracture. Also, the purer and the bigger granules the carbonate have, for example limestone, the more difficulty to produce structural fracture. The relationship between the structural fracture and the rock mechanics parameters is discussed.
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Analysis of the Surface Temperature over Keerqin Sand Aera in Inner Mongolia
ZHANG Peng,ZHANG Hongsheng,DU Jinlin,LIU Huizhi
Acta Scientiarum Naturalium Universitatis Pekinensis   
Abstract （878）            Save
Using the micrometeorological data obtained over the moving sand dune in Keerqin sand area in Inner Mongolia in summer of 2001 and spring of 2002, the surface temperature was determined and the characteristics were analyzed over the sand dune area. The idea is using discrete Fourier transform on the temperatures of different layers and applying soil heat conduction equation. The results are that soil temperature conductivity ratios which are calculated from the decline of the soil temperature amplitude and phase difference agree well under the assumption of layered homogeneity. The surface temperature was calculated using the relationship of the soil temperature conductivity ratios at different depths and the amplitude and phase of dominant and harmonic frequencies of soil temperature. The surface temperatures calculated from observed soil temperatures at 5 cm and 10 cm depth show a good agreement. The amplitude of soil temperature waves decreases exponentially with depth. The diurnal variation of soil temperature at 80 cm is small.
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