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The low-latitude sodium layer:comparative data from lidar observations at Hainan,China and São Paulo,Brazil

Earth and Planetary Physics 2025年第1期9卷 39-53页

作者： Fang Wu Jing Jiao guotao yang LiFang Du ZhengKuan Liu HaoRan Zheng JiXin Guo ShaoHua Gong YaJun Zhu State Key Laboratory of Space Weather National Space Science CenterChinese Academy of SciencesBeijing 100190China Hainan National Field Science Observation and Research Observatory for Space Weather National Space Science CenterChinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China China-Brazil Joint Laboratory for Space Weather NSSC/INPESão Josédos Campos 12227-010Brazil School of Physics and Electronics Engineering Hainan Normal UniversityHaikou 571158China

Physical and chemical processes observed in the mesosphere and thermosphere above the Earth’s low latitudes are complex and highly interrelated to activity in the low-latitude *** sodium detected by lidar can yield clues to dynamic and chemical processes in these spatial layers above the Earth’s *** paper is based on sodium layer data collected at two low-latitude stations,one in the northern hemisphere and one in the *** low-latitude sodium layer exhibits conspicuous seasonal variations in shape,density,and altitude;these variations are similar between Earth’s hemispheres:sodium layer density at both stations reaches its seasonal maximum in autumn and minimum in ***,maximal Na density over Brazil is greater than that over *** variations of Na density above the two low-latitude stations are also similar;at both,maxima are observed before *** variations of the Na layer over Brazil that differ from those observed in the northern hemisphere may be related to the South Atlantic Magnetic Anomaly(SAMA)or fountain *** suggest that low-latitude Na layer data may provide useful additional evidence that could significantly improve the low-latitude part of the WACCM-Na model.

关键词： metallic sodium layer seasonal variation nocturnal variation lidar

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Studying the stability of the middle atmosphere (30―60km) over Wuhan by Rayleigh lidar

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Chinese Science Bulletin 2006年第21期51卷 2657-2661页

作者： CHANG Qihai yang guotao SONG Juan GONG Shunsheng Wuhan Institute of Physics and Mathematics Chinese Academy of Sci-ences Wuhan 430071 China

The stability of the middle atmosphere ranging from 30 km to 60 km over Wuhan is elementarily studied, according to the observational data obtained in about one year through the WIPM Rayleigh lidar. The stability parameter (buoyancy frequency squared), which was obtained through the temperature field, shows that the middle atmosphere over Wuhan is stable all the year round, but the sta- bility appears variable because the stability of sum- mer and winter is lower, and that of spring and au- tumn is higher.

关键词：瑞利激光雷达中层大气浮力频率大气稳定度

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Study on the influencing factors of peasants' subjective well-being

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Chinese Journal of Population,Resources and Environment 2016年第2期16卷 112-122页

作者： guotao yang Tao Jiang Zihe Liu School of Economics and Management Ningxia University

On the basis of data collected from Liupanshan poverty-ridden areas,the paper selects 24 variables under 4 groups to figure out the influencing factors of subjective well-being(SWB) of peasants in ecological migration with the method of Ordered Probit *** is shown in the results,variables under peasants' personal endowment group and resource of the development group have little impact on peasants' *** variables with observable impact are concentrated in the living condition group and the public atmosphere group.

关键词： Ecological migration SWB Ordered Probit Regression

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Use of Plastic Correction Formula to Improve Accuracy of Welding Residual Stress Test with Blind-Hole Method

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Transactions of Tianjin University 2018年第5期24卷 480-488页

作者： Qiu Zhao Kongsheng Chen Meizhong Chen Bruno Briseghella Zhiyong Guo guotao yang College of Civil Engineering Fuzhou University School of Civil and Environmental Engineering Centre for Infrastructure Engineering and Safetythe University of New South WalesUNSW

The blind-hole method is the most widely used approach to experimentally determine the distribution of residual stress. This paper aims to improve test accuracy of welding residual stress and conducts an experimental study on the strain release factors involved when using the blind-hole method for Q235 and Q345, two steels commonly used in building structures. The ranges of strain release factors A and B in the elastic stage, the effects of strain release factors on residual stress calculated values, and the plastic corrected strain release factors are analyzed considering of the effect of plastic deformation around the blind hole on measurement accuracy. Finally, a simplified calculation formula to determine strain release factors is proposed for use with the blind-hole method. Results show that in the elastic stage, strain release factor A for Q235 and Q345 ranges from-0.399 to-0.525 and strain release factor B from-0.791 to-0.960. Changing the strain release factors A and B shows that calculated residual tensile stress varies in relation to a decrease in both factor values. However, there is a increase in calculated residual compressive stress with a decrease in the strain release factor A value, but there is an decrease with a decrease in strain release factor B value. Calculated residual stress applied to elastic strain release factors is compared with that applied to amended plastic strain release factors for Q235 steel. The maximum deviation between calculated residual stress and test stress is reduced from 21.1 to 1.0%,and for Q345 steel from 26.5 to 1.2%. It is thus evident that the plastic correction formula proposed in this paper can be used in calculations when conducting a residual stress test.

关键词： Blind-hole method Welding residual stress·Calibration test Strain release factor Plastic correction

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The first observation of the atmospheric tides in the mesosphere and lower thermosphere over Hainan, China

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Chinese Science Bulletin 2010年第11期55卷 1059-1066页

作者： JIANG GuoYing XU JiYao SHI JianKui yang guotao WANG Xiao YAN ChunXiao State Key Laboratory of Space Weather Center for Space Science and Applied Research Chinese Academy of Sciences Beijing 100190 China

Fuke (19.5°N, 109.1°E) meteor radar is the first radar of the low latitudes of China, which is used to detect the wind in the meso- sphere and lower thermosphere. In this paper, by using the wind data near three months (1 February-20 April, 2009), we first present the variation of the atmospheric diurnal tide, semidiurnal tide and mean wind in the height range 80-100 km over the low latitudes of China. The results from our analysis are summarized below. During spring months, there are quite strong tides in the mesopause region of Fuke. The diurnal tidal amplitude is significantly larger than the amplitude of semidiurnal tide, and the maximum amplitude (about 100 m/s) of diurnal tide appear in the meridional wind. The vertical phases of both diurnal tide and semidiurnal tide propagate downward. In addition, the observed tides are compared with the linear tide model (Global Scale Wave Model, GSWM02), and the results show that Fuke diurnal tide agrees well with the model, but there are many differences between Fuke semidiurnal tide and the results from model.

关键词：潮汐观测中间层中国大气热层低纬度地区线性模型海南

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Recent advances in recyclable thermosets and thermoset composites based on covalent adaptable networks

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Journal of Materials Science & Technology 2021年第33期92卷 75-87页

作者： Yihe Zhang Li Zhang guotao yang Yalin Yao Xu Wei Tianchi Pan Juntao Wu Moufeng Tian Penggang Yin Beijing Key Laboratory of Materials Utilization of Nonmetallic Minerals and Solid Wastes School of Materials Science and TechnologyChina University of GeosciencesBeijing 100083China Beijing Composite Materials Co. Ltd.Beijing 102101China State Key Laboratory of Advanced Fiber Composites Beijing 102101China School of Chemistry Beihang UniversityBeijing 100191China

Recyclable thermosets and thermoset composites with covalent adaptable networks(CANs,or dynamic covalent networks) have attracted considerable attention in recent years due to the combined merits of excellent mechanical and thermal properties,and chemical stabilities of traditional thermosets and recyclable,remoldable,and reprocessable attributes of *** this paper,we present an overview of the current strategies for synthesizing recyclable thermosets based on CANs,which involve recyclability,reprocessability,and possible *** recent literature examples are categorized based on the underlying controlled-cleavable linkages such as transesterification,DA/retro-DA chemistry,imine bonds,disulfide metathesis,dynamic B-O bonds,hemiaminals/hexahydrotriazines,and acetal *** degradation and malleability methods and resulting mechanical properties of the recycled thermosets and thermoset composites are *** emerging applications of recyclable thermosets and thermoset composites,with emphasis on their usage in adhesives,biomedical materials,wearable devices,coatings,and 3D printing materials,are also ***,a perspective on the challenges and future perspectives is briefly summarized.

关键词： Covalent adaptable networks(CANs) Recyclable Crosslink Degradation Property

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Lidar observation campaigns on diurnal variations of the sodium layer in Beijing and Wuhan, China

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Science China Earth Sciences 2015年第8期58卷 1377-1386页

作者： GONG ShaoHua yang guotao CHENG XueWu GONG Shun Sheng XU JiYao LI FaQuan GONG Wei WANG JiHong School of Physics and Electronics Engineering Hainan Normal University State Key Laboratory of Space Weather National Space Science Center Chinese Academy of Sciences Laboratory of Optoelectronics Wuhan Institute of Physics and Mathematics Chinese Academy of Sciences State Key Laboratory of Information Engineering in Surveying Mapping and Remote Sensing Wuhan University

Based on observations from daytime lidars in eastern China,diurnal cycles of the sodium layer over Wuhan(30.5°N,114.6°E)and Beijing(40.5°N,116°E)are *** variations of Na density,root mean square(RMS)layer width,and centroid height of the sodium layer are *** reveal that the large diurnal cycles of the sodium layer are controlled mainly by 24-hr oscillations at the two observation *** diurnal variation of the sodium layer over Wuhan was modulated mainly by tidal perturbations during the lidar observation ***,the diurnal variation over Beijing was controlled principally by photoionization and photochemistry effects during another campaign,and there was little evidence of direct tidal *** comparisons suggest that the diurnal variation of the sodium layer perhaps has obvious regional characteristics across *** variation can be either controlled mainly by tidal perturbations or by photoionization and photochemistry effects in different seasons.

关键词： daytime lidar diurnal variations of the sodium layer photochemistry effects tidal perturbations

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A statistical study on the correlation between sporadic Ca+layer and Es in Beijing(40.5°N,116°E)

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Earth and Planetary Physics 2024年第5期8卷 753-761页

作者： YuChang Xun ZhiShan Chen LiFang Du HaoRan Zheng Jing Jiao ZeLong Wang ShaoHua Gong guotao yang College of Physics College of Electronic Information and Optical EngineeringTaiyuan University of TechnologyTaiyuan 030024China State Key Laboratory of Space Weather National Space Science CenterChinese Academy of SciencesBeijing 100190China School of Science Jiangsu University of Science and TechnologyZhenjiang Jiangsu 212100China School of Physics and Electronics Engineering Hainan Normal UniversityHaikou 571158China

From April 2020 to June 2022,a Ca+lidar with dual-wavelength and narrow-band emitting lasers utilizing all-solid-state technology was employed to conduct observations in Beijing(40.41°N,116.01°E)for a total duration of 1797.79 hours over 280 nights.A total of 286 sporadic Ca+layers were observed,with heights ranging from 88 to 120 km and densities varying from 5.33 to 2200 cm^(-3).We simultaneously observed the ionosonde,located 28 km from the lidar,and found a correlation of 61.89%between the sporadic Ca+layer and the sporadic E *** the sporadic Ca+layer has a downward phase trend,there is a correlation of 76.84%.By excluding the influence of ionosonde sensitivity,we focus only on calcium ions that have a density exceeding 140 cm^(-3),which exhibit a correlation of82.25%.Above 100 km,the correlation significantly increases,reaching approximately 90%.Furthermore,the correlation between the sporadic Ca+layer and the sporadic E layer is particularly noticeable during the summer season,reaching around 90%.This phenomenon can be attributed to the variations in metal ions that occur during different seasons.

关键词： layer lidar exceeding

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Study on the dynamic contact relationship between layers under temperature gradients in CRTSⅢ ballastless track

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High-Speed Railway 2024年第3期2卷 133-142页

作者： Lei Zhao Guotang Zhao guotao yang Hao Jin Chenxi Li Railway Engineering Research Institute China Academy of Railway Sciences Co.LtdBeijing 100081China China State Railway Group Co. Ltd.Beijing 100844China School of Transportation Southeast UniversityNanjing 211189China School of Traffic and Transportation Beijing Jiaotong UniversityBeijing 100081China

In areas with large temperature differences,the uneven distribution of temperatures in the CRTS III ballastless track slab due to daytime sunlight can cause warpage deformation,leading to periodic rail irregularities that increase the wheel-rail impact of high-speed vehicles and accelerate track structure ***,it is necessary to study the dynamic contact relationship between the composite slab and the base plate during vehicle *** results of the study show that:1)Under the influence of temperature gradients,the composite slab tends to deform *** a positive temperature gradient,the middle part of the track slab bulges upward,causing the slab to be supported by its four ***,with a negative temperature gradient,the four corners of the track slab bulge upward,resulting in the slab being supported by its center.2)Temperature gradients can lead to separation between the composite slab and the base plate,reducing the contact area between *** vehicle running,the contact area between layers gradually increases,but the separation cannot be completely closed.3)The temperature gradient significantly affects the vertical displacement of the *** vertical displacement in the middle of the slab increases with a positive temperature *** contrast,the vertical displacement at the ends of the slab increases with a negative temperature gradient.4)The stress of self-compacting concrete at the side position significantly increases under a positive temperature gradient,with the vertical stress increasing by 2.7 times when the temperature gradient increases from 0 to 90℃·m^(-1).

关键词： High-speed railway Ballastless track Temperature gradient Periodic irregularities Interlayer contact

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Observation of the Double Sodium Layer Over Haikou,China by Lidar

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空间科学学报 2013年第4期33卷 410-412页

作者： ZHANG Tiemin WANG Jihong FU Jun yang Dali yang Xianchang WU Wei yang guotao College of Physics and Electronic Engineering Hainan Normal University State Key Laboratory of Space Weather Center for Space Science and Applied ResearchChinese Academy of Sciences

A Double Sodium Layer(DSL) structure was observed during the night of August 22, 2011 over Haikou,China(20°N,110°E) by Na *** DSL comprised a typical sodium layer at altitudes of 80～105km and a higher sodium layer at altitudes of 105～115km in about 0.5 h.A wavelength of 589 nm dye laser pumped by a Nd:YAG laser was used to make the measurement. The backscattered fluorescence photons from the sodium layer were collected by a telescope with a primary mirror of 1000 mm in *** sodium density of these layers during the nighttime observation in the Mesosphere and Lower-Thermosphere(MLT) was studied.

关键词： Lidar Double Sodium Layer(DSL) Mesosphere and Lower-Thermosphere(MLT)

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