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101.
1 ObservationalvelocityfieldWeanalyseHβspectraobtainedatYunnanObservatorywiththetwo dimensionMulti Wave bandSpectra SpectroHelioGraph (MW SSHG) (XuanandLin 1 993) .ThePFLsappearedat0 1 :0 4UTofAugust 1 7,1 989onthewesternsolarlimbabovethelargeactiveregion (AR 5 6 2 9,S1 5°;W 1 … 相似文献
102.
In the Loess Plateau in Northern China,repeated freeze–thaw(FT)cycles deteriorate the strength and structure of loess as a foundation soil,resulting in the instability or failure of supporting structure.Lignosulfonate is an eco–material,utilized as an effective and nontraditional stabilizer to improve the engineering properties of metastable soils.A series of laboratory tests,including unconfined compression tests,cyclic loading–unloading tests and scanning electron microscopy,on calcium lignosulfonate(CL)-and sodium lignosulfonate(SL)-stabilized loess were performed to investigate the stabilization effect,deterioration mechanisms of the FT cycles,and the resistance to FT cycles.Two traditional stabilizers,quicklime(QL)and sodium silicate(SS),were selected,and the engineering properties of QL-and SS-stabilized loess were compared with those of CL-and SLstabilized loess.The results showed that the strength values of CL-and SL-stabilized loess specimens decreased by 34.2%and 50%respectively,after 20 FT cycles,whereas those of the traditionally SS-and QL-stabilized specimens decreased by 85.3%and 82.87%,respectively.The elastic moduli of SL-and QL-stabilized loess specimens decreased by 22.1%and 92.0%,respectively.The mean energy dissipations of nontraditionally treated specimens also decreased significantly less than those of traditionally treated specimens.Overall,the results showed CL and SL had better stabilization effects on engineering properties of loess than QL and SS,and their stabilized loess specimens exhibited stronger resistance to FT cycles.The study findings demonstrated the significant potential of lignosulfonate for extensive application in cold loess areas. 相似文献
103.
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????????????????о??????????????????(DEM)?????????????е??????????????????о????????????40??~50??????????18??~30????????????50~70 m?????????????????????????????? 相似文献
104.
An Evidence of Aerosol Indirect Effect on Stratus Clouds from the Integrated Ground-Based Measurements at the ARM Shouxian Site 下载免费PDF全文
TANG Jin-Ping WANG Pu-Cai DUAN Min-Zheng CHEN Hong-Bin XIA Xiang-Ao LIAO Hong 《大气和海洋科学快报》2011,4(2):65-69
The aerosol effect on clouds was explored using remote sensing of aerosol and cloud data at Shouxian, China. Non-precipitation, ice-free, and overcast clouds were firstly chosen by a combination of sky images from the Total Sky Imager (TSI), cloud base heights from the Ceilometer, and vertical temperature profiles from the Balloon-Borne Sounding System (BBSS). Six cases were chosen in summer, and seven in autumn. The averaged cloud effective radii (re), cloud optical depth (COD), aerosol total light scattering coefficient (σ), and liquid water path (LWP) are, respectivey, 6.47 μm, 35.4, 595.9 mm-1, 0.19 mm in summer, and 6.07 μm, 96.0, 471.7 mm-1, 0.37 mm in autumn. The correlation coefficient between re and σ was found to change from negative to positive value as LWP increases. 相似文献
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108.
电离层闪烁是影响卫星导航系统定位性能的重要因素之一。电离层闪烁可造成GNSS载噪比降低,测量误差增大,载波周跳次数增多,电离层修正精度降低,定位用精度因子变大等影响。中国南方区域是全球电离层闪烁多发区之一,电离层闪烁影响的时空范围和程度较大,是我国卫星导航应用应关注的问题。针对电离层闪烁影响,提出了我国卫星导航系统应用中可行的针对性减缓措施。 相似文献
109.
由于有限视角、稀疏布站等原因,地基G PS电离层层析成像存在垂直分辨率不高的问题,联合掩星进行电离层层析成像是一个重要的解决途径。一方面地基G PS观测能保证电离层层析成像的时间连续性和区域覆盖性;另一方面由于掩星信号能够提供地基G PS没有的水平射线信息,提升了电离层层析成像的垂直分辨率水平。利用地基GPS站与COSMIC卫星的掩星观测进行的仿真结果表明:与仅利用地基G PS相比,联合掩星进行电离层层析成像,不仅在电离层电子密度反演精度方面有明显提升,而且在电离层F2层峰值高度(hm F2)和电离层总电子含量(T EC )的精度方面同样有明显提高。 相似文献
110.
Hongfeng Yang Dun Wang Rumeng Guo Mengyu Xie Yang Zang Yue Wang Qiang Yao Chuang Cheng Yanru An Yingying Zhang 《中国地震研究》2022,(1):4-14
The MS 6.9 Menyuan earthquake in Qinghai Province, west China is the largest earthquake by far in 2022. The earthquake occurs in a tectonically active region, w... 相似文献