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Three-dimensional thermohaline structure estimation derived from HY-2 satellite data over the Maritime Silk Road and its applications
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作者 Zhiqiang Chen Xidong Wang +4 位作者 Xiangyu Wu Yuan Cao Zikang He Dakui Wang Jian Chen 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2024年第5期41-53,共13页
Estimated ocean subsurface fields derived from satellite observations provide potential data sources for operational marine environmental monitoring and prediction systems.This study employs a statistic regression rec... Estimated ocean subsurface fields derived from satellite observations provide potential data sources for operational marine environmental monitoring and prediction systems.This study employs a statistic regression reconstruction method,in combination with domestic autonomous sea surface height and sea surface temperature observations from the Haiyang-2(HY-2)satellite fusion data,to establish an operational quasi-realtime three-dimensional(3D)temperature and salinity products over the Maritime Silk Road.These products feature a daily temporal resolution and a spatial resolution of 0.25°×0.25°and exhibit stability and continuity.We have demonstrated the accuracy of the reconstructed thermohaline fields in capturing the 3D thermohaline variations through comprehensive statistical evaluations,after comparing them against Argo observations and ocean analysis data from 2022.The results illustrate that the reconstructed fields effectively represent seasonal variations in oceanic subsurface structures,along with structural changes resulting from mesoscale processes,and the upper ocean’s responses to tropical cyclones.Furthermore,the incorporation of HY-2 satellite observations notably enhances the accuracy of temperature and salinity reconstructions in the Northwest Pacific Ocean and marginally improves salinity reconstruction accuracy in the North Indian Ocean when compared to the World Ocean Atlas 2018 monthly climatology thermohaline fields.As a result,the reconstructed product holds promise for providing quasi-real-time 3D temperature and salinity field information to facilitate fast decisionmaking during emergencies,and also offers foundational thermohaline fields for operational ocean reanalysis and forecasting systems.These contributions enhance the safety and stability of ocean subsurface activities and navigation. 展开更多
关键词 HY-2 satellite observations subsurface structures reconstruction Maritime Silk Road operational thermohaline product
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Performance evaluation of HY-2 series satellites in marine gravity field recovery
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作者 Ruijie Hao Xiaoyun Wan Keyan Zhang 《Geodesy and Geodynamics》 EI CSCD 2024年第4期397-403,共7页
China has successfully launched four Haiyang-2(HY-2)series altimetry satellites.HY-2A has attracted significant attention in gravity field recovery,but the performance of other HY-2 series satellites,including HY-2B/C... China has successfully launched four Haiyang-2(HY-2)series altimetry satellites.HY-2A has attracted significant attention in gravity field recovery,but the performance of other HY-2 series satellites,including HY-2B/C/D,is seldom discussed.This study evaluated the performance of all the HY-2 series satellites in recovering marine gravity field.First,the crossover discrepancies in sea surface height of the four satellites,HY-2A,HY-2B,HY-2C,and HY-2D,were analyzed to assess their altimetry stability.It was found that HY-2B had the best altimetry quality,followed by HY-2D.Subsequently,different combina-tions of altimetry data were used to calculate vertical deflections and gravity anomalies in the South China Sea(112°E-119°E,12°N-20°N).The results showed that combining data from HY-2B,HY-2C,and HY-2D improved the inversion accuracy of gravity anomalies by 0.3 mGal compared to using HY-2A data alone.HY-2C and HY-2D contributed to enhancing the accuracy of the east component of vertical deflections. 展开更多
关键词 satellite altimetry HY-2 Sea surfaceheight Marinegravityfield
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Retrieval of Antarctic sea ice freeboard and thickness from HY-2B satellite altimeter data
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作者 Yizhuo Chen Xiaoping Pang +3 位作者 Qing Ji Zhongnan Yan Zeyu Liang Chenlei Zhang 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2024年第3期87-101,共15页
Antarctic sea ice is an important part of the Earth’s atmospheric system,and satellite remote sensing is an important technology for observing Antarctic sea ice.Whether Chinese Haiyang-2B(HY-2B)satellite altimeter da... Antarctic sea ice is an important part of the Earth’s atmospheric system,and satellite remote sensing is an important technology for observing Antarctic sea ice.Whether Chinese Haiyang-2B(HY-2B)satellite altimeter data could be used to estimate sea ice freeboard and provide alternative Antarctic sea ice thickness information with a high precision and long time series,as other radar altimetry satellites can,needs further investigation.This paper proposed an algorithm to discriminate leads and then retrieve sea ice freeboard and thickness from HY-2B radar altimeter data.We first collected the Moderate-resolution Imaging Spectroradiometer ice surface temperature(IST)product from the National Aeronautics and Space Administration to extract leads from the Antarctic waters and verified their accuracy through Sentinel-1 Synthetic Aperture Radar images.Second,a surface classification decision tree was generated for HY-2B satellite altimeter measurements of the Antarctic waters to extract leads and calculate local sea surface heights.We then estimated the Antarctic sea ice freeboard and thickness based on local sea surface heights and the static equilibrium equation.Finally,the retrieved HY-2B Antarctic sea ice thickness was compared with the CryoSat-2 sea ice thickness and the Antarctic Sea Ice Processes and Climate(ASPeCt)ship-based observed sea ice thickness.The results indicate that our classification decision tree constructed for HY-2B satellite altimeter measurements was reasonable,and the root mean square error of the obtained sea ice thickness compared to the ship measurements was 0.62 m.The proposed sea ice thickness algorithm for the HY-2B radar satellite fills a gap in this application domain for the HY-series satellites and can be a complement to existing Antarctic sea ice thickness products;this algorithm could provide long-time-series and large-scale sea ice thickness data that contribute to research on global climate change. 展开更多
关键词 HY-2B satellite altimeter classification decision tree sea ice freeboard and thickness Antarctic waters
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Comparative investigation of microstructure and high-temperature oxidation resistance of high-velocity oxy-fuel sprayed CoNiCrAlY/nano-Al_(2)O_(3) composite coatings using satellited powders 被引量:2
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作者 Pejman Zamani Zia Valefi 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2023年第9期1779-1791,共13页
Satellited CoNiCrAlY–Al_(2)O_(3)feedstocks with 2wt%, 4wt%, and 6wt% oxide nanoparticles and pure CoNiCrAlY powder were deposited by the high-velocity oxy fuel process on an Inconel738 superalloy substrate. The oxida... Satellited CoNiCrAlY–Al_(2)O_(3)feedstocks with 2wt%, 4wt%, and 6wt% oxide nanoparticles and pure CoNiCrAlY powder were deposited by the high-velocity oxy fuel process on an Inconel738 superalloy substrate. The oxidation test was performed at 1050℃ for 5, 50, 100,150, 200, and 400 h. The microstructure and phase composition of powders and coatings were characterized by scanning electron microscopy and X-ray diffraction, respectively. The bonding strength of the coatings was also evaluated. The results proved that with the increase in the percentage of nanoparticles(from 2wt% to 6wt%), the amount of porosity(from 1vol% to 4.7vol%), unmelted particles, and roughness of the coatings(from 4.8 to 8.8 μm) increased, and the bonding strength decreased from 71 to 48 MPa. The thicknesses of the thermally grown oxide layer of pure and composite coatings(2wt%, 4wt%, and 6wt%) after 400 h oxidation were measured as 6.5, 5.5, 7.6, and 8.1 μm, respectively.The CoNiCrAlY–2wt% Al_(2)O_(3)coating showed the highest oxidation resistance due to the diffusion barrier effect of well-dispersed nanoparticles. The CoNiCrAlY–6wt% Al_(2)O_(3)coating had the lowest oxidation resistance due to its rough surface morphology and porous microstructure. 展开更多
关键词 MCrAlY coating CoNiCrAlY-Al_(2)O_(3)composite satellited feedstock MICROSTRUCTURE high-temperature oxidation high-velocity oxy-fuel spraying
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免疫性复发性流产Bcl-2、E-cad的表达及影响因素分析
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作者 董洁 穆艳超 王沙沙 《罕少疾病杂志》 2024年第7期139-141,共3页
目的探讨与分析免疫性复发性流产(RSA)患者B淋巴细胞瘤-2(Bcl-2)、E-钙黏蛋白(E-cad)的表达及影响因素。方法2020年8月到2023年1月选择在我院妇产科建档的免疫性RSA产妇40例作为研究组,同期选择在我院妇产科建档的人工流产产妇40例作为... 目的探讨与分析免疫性复发性流产(RSA)患者B淋巴细胞瘤-2(Bcl-2)、E-钙黏蛋白(E-cad)的表达及影响因素。方法2020年8月到2023年1月选择在我院妇产科建档的免疫性RSA产妇40例作为研究组,同期选择在我院妇产科建档的人工流产产妇40例作为对照组,检测两组子宫蜕膜组织中Bcl-2、E-cad表达水平,分析免疫性RSA的影响因素。结果研究组的Bcl-2、E-cad表达阳性率为75.00%、87.50%,显著高于对照组的25.00%、35.00%(P<0.05)。在研究组40例患者中,病理表现为蜕膜炎性坏死4例、绒毛水泡状退行性变9例、绒毛炎性坏死组织27例。在研究组40例患者中,蜕膜炎性坏死患者的Bcl-2、E-cad表达阳性率高于绒毛水泡状退行性变、绒毛炎性坏死组织(P<0.05),绒毛水泡状退行性变患者的Bcl-2、E-cad表达阳性率高于绒毛炎性坏死组织(P<0.05);多因素回归分析显示Bcl-2、E-cad表达阳性率都为导致免疫性复发性流产的重要影响因素(P<0.05)。结论免疫性RSA患者多伴随有Bcl-2、E-cad的高表达,病理特征类型多样,Bcl-2、E-cad表达阳性为导致免疫性复发性流产的重要影响因素。 展开更多
关键词 免疫性复发性流产 e-钙黏蛋白 B淋巴细胞瘤-2 影响因素
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e-抗原(HBeAg)阳性慢性乙型肝炎采用恩替卡韦联合聚乙二醇干扰素α-2a治疗的疗效观察
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作者 王瑞萍 《中国科技期刊数据库 医药》 2024年第6期0119-0122,共4页
观察e-抗原(HBeAg)阳性慢性乙型肝炎患者接受治疗时,应用恩替卡韦、聚乙二醇干扰素α-2a联合治疗的疗效。方法 截取在2023年1月至2023年12月进入我院,接受治疗的68例e-抗原(HBeAg)阳性慢性乙型肝炎患者,随机2组,观察疗效。结果 比较两... 观察e-抗原(HBeAg)阳性慢性乙型肝炎患者接受治疗时,应用恩替卡韦、聚乙二醇干扰素α-2a联合治疗的疗效。方法 截取在2023年1月至2023年12月进入我院,接受治疗的68例e-抗原(HBeAg)阳性慢性乙型肝炎患者,随机2组,观察疗效。结果 比较两组的治疗效果,研究组的有效率更改,差异有意义(P<0.05)。结论 当把恩替卡韦联合聚乙二醇干扰素α-2a联的治疗方式,应用在e-抗原(HBeAg)阳性慢性乙型肝炎患者,治疗效果明显,能够改善患者的肝功能、血清学、病毒学的应答情况,维护患者的身心健康,适合临床推广。 展开更多
关键词 聚乙二醇干扰素Α-2A 治疗效果 e-抗原(HBeAg)阳性 恩替卡韦 慢性乙型肝炎
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Positioning reduction in the real-time phase of Chang'E-2 satellite 被引量:2
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作者 LI JinLing LIU Li +1 位作者 ZHENG WeiMin SUN ZhongMiao 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS 2012年第2期371-374,共4页
The precision of VLBI tracking delays and the positioning reduction results during the real-time tracking phase of the Chang'E-2 satellite are statistically analyzed.The application of the positioning reduction to... The precision of VLBI tracking delays and the positioning reduction results during the real-time tracking phase of the Chang'E-2 satellite are statistically analyzed.The application of the positioning reduction to the real-time monitoring of pivotal arcs of the Chang'E-2 satellite is discussed.The technical specifications of the tests of tracking and control systems in X-band are estimated and evaluated via the positioning reduction method.Useful methodology and software are prepared and practical experience in engineering and technology is accumulated for the follow-up lunar and deep space explorations of China. 展开更多
关键词 实时跟踪 过定位 卫星 VLBI 统计分析 实时监控 测试技术 控制系统
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Auto-compensation of velocity-height ratio for Chang’E-2 satellite CCD stereo camera 被引量:4
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作者 XUE Bin ZHAO BaoChang +7 位作者 YANG JianFeng GAO Weit QIAO WeiDong MA XiaoLong ZHANG Bo LIU JiaHang ZHAO Wei JING Juan Juan 《Science China(Technological Sciences)》 SCIE EI CAS 2011年第9期2243-2246,共4页
The TDI-CCD imaging method using auto-compensation of velocity-height ratio (VHR) was applied to Chang’E-2 satellite CCD stereo camera.Factors that influence the image quality of the camera were discussed,among which... The TDI-CCD imaging method using auto-compensation of velocity-height ratio (VHR) was applied to Chang’E-2 satellite CCD stereo camera.Factors that influence the image quality of the camera were discussed,among which the mismatch error in VHR was found to be the main cause.An auto-compensation scheme for VHR was developed.The validity and effectiveness were proved by the on-orbit high quality images. 展开更多
关键词 自动补偿 立体相机 CCD 卫星 速度 图像质量 VHR 成像方法
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椰子芯叶2种挥发物对红棕象甲成虫行为影响
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作者 吕朝军 钟宝珠 +1 位作者 袁伟钦 李文莲 《山西农业大学学报(自然科学版)》 CAS 北大核心 2024年第3期83-88,共6页
[目的]阐明红棕象甲对椰子芯叶挥发物E,E-2,4-壬二烯醛和反式-2-壬醛的行为学反应。[方法]采用室内生物测定法,研究了红棕象甲室内饲养个体和田间野生个体对椰子芯叶2种挥发物的室内选择行为,并分析了椰子挥发物处理对红棕象甲雌虫刺探... [目的]阐明红棕象甲对椰子芯叶挥发物E,E-2,4-壬二烯醛和反式-2-壬醛的行为学反应。[方法]采用室内生物测定法,研究了红棕象甲室内饲养个体和田间野生个体对椰子芯叶2种挥发物的室内选择行为,并分析了椰子挥发物处理对红棕象甲雌虫刺探、产卵的影响。[结果](1)经E,E-2,4-壬二烯醛处理后,室内饲养的雄虫对其产生显著正偏好;在经反式-2-壬醛处理后,室内饲养的雌虫和雄虫均对挥发物处理组表现出显著正偏好。(2)采用E,E-2,4-壬二烯醛处理后,室内饲养的雌虫对处理组椰皮的刺探数量显著高于对照组。(3)经E,E-2,4-壬二烯醛处理后,所有试虫的单雌产卵量和刺探成功产卵率,与对照相比均未达到显著差异水平。而经反式-2-壬醛处理后,室内饲养的红棕象甲雌虫对椰皮的产卵选择偏好显著高于对照处理组,且刺探产卵成功率与对照相比达到了极显著水平。(4)在对反式-2-壬醛和E,E-2,4-壬二烯醛处理的竞争选择结果中,室内饲养和田间诱捕的红棕象甲在行为选择、刺探及产卵中均未表现出显著差异。[结论]不同红棕象甲种群对椰子芯叶挥发物E,E-2,4-壬二烯醛和反式-2-壬醛的趋向偏好存在差异,并影响后期的刺探和产卵成功率,同时红棕象甲对这2种挥发物的竞争选择无差异。 展开更多
关键词 红棕象甲 E e-2 4-壬二烯醛 反式-2-壬醛 行为反应
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基于ICESat-2多波束激光测高数据的全球海洋重力异常反演分析
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作者 李真 郭金运 +3 位作者 孙中苗 贾永君 黄令勇 孙和平 《测绘学报》 EI CSCD 北大核心 2024年第2期252-262,共11页
卫星测高技术是获取精细海洋重力数据的重要技术手段之一。常规卫星测高反演海洋重力异常主要是利用沿轨测高数据,而跨轨数据因较长的时间间隔或者稀疏的地面轨间距往往不能用于海洋重力异常反演,进而影响了海洋重力异常模型精度的进一... 卫星测高技术是获取精细海洋重力数据的重要技术手段之一。常规卫星测高反演海洋重力异常主要是利用沿轨测高数据,而跨轨数据因较长的时间间隔或者稀疏的地面轨间距往往不能用于海洋重力异常反演,进而影响了海洋重力异常模型精度的进一步改善。新型激光测高ICESat-2能够同时获得3对光束观测数据,相邻激光束的地面间距约为3 km,为结合跨轨数据改善海洋重力异常模型提供了可能。本文首先给出了集成沿轨和跨轨数据反演海洋重力异常的处理策略;然后,分别利用沿轨数据和集成的数据构建了ICESat-2全球海洋重力异常模型(IS2Gra_alo和IS2Gra_alo_acr),结果表明通过补充跨轨数据能够有效提高沿轨数据反演海洋重力异常的精度,并验证了ICESat-2测高数据反演全球海洋重力异常的可靠性。此外,本文还探讨了ICESat-2不同跨轨数据组合对海洋重力异常模型反演精度的影响,在沿轨数据的基础上集成适当距离的跨轨观测数据能够有利于改善海洋重力异常模型的精度。本文研究为后续SWOT宽刈幅测高数据和我国双星跟飞模式测高数据反演海洋重力异常模型提供了参考意义。 展开更多
关键词 ICESat-2 卫星激光测高 海洋重力异常 垂线偏差 海面高
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Evaluation of the Long-term Performance of Microwave Radiation Imager Onboard Chinese Fengyun Satellites 被引量:1
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作者 Wenying HE Hongbin CHEN +2 位作者 Xiang’ao XIA Shengli WU Peng ZHANG 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2023年第7期1257-1268,共12页
Accurate brightness temperature(BT)is a top priority for retrievals of atmospheric and surface parameters.Microwave Radiation Imagers(MWRIs)on Chinese Fengyun-3(FY-3)serial polar-orbiting satellites have been providin... Accurate brightness temperature(BT)is a top priority for retrievals of atmospheric and surface parameters.Microwave Radiation Imagers(MWRIs)on Chinese Fengyun-3(FY-3)serial polar-orbiting satellites have been providing abundant BT data since 2008.Much work has been done to evaluate short-term MWRI observations,but the long-term performance of MWRIs remains unclear.In this study,operational MWRI BTs from 2012–19 were carefully examined by using simultaneous Advanced Microwave Scanning Radiometer 2(AMSR2)BTs as the reference.The BT difference between MWRI/FY3B and AMSR2 during 2012–19 increased gradually over time.As compared with MWRI/FY3B BTs over land,those of MWRI/FY3D were much closer to those of AMSR2.The ascending and descending orbit difference for MWRI/FY3D is also much smaller than that for MWRI/FY3B.These results suggested the improvement of MWRI/FY3D over MWRI/FY3B.A substantial BT difference between AMSR2 and MWRI was found over water,especially at the vertical polarization channels.A similar BT difference was found over polar water based on the simultaneous conical overpassing(SCO)method.Radiative transfer model simulations suggested that the substantial BT differences at the vertical polarization channels of MWRI and AMSR2 over water were partly contributed by their difference in the incident angle;however,the underestimation of the operational MWRI BT over water remained a very important issue.Preliminary assessment of the operational and recalibrated MWRI BT demonstrated that MWRI BTs were substantially improved after the recalibration,including the obvious underestimation of the operational MWRI BT at the vertical polarization channels over water was corrected,and the time-dependent biases were reduced. 展开更多
关键词 FY-3 satellites MWRI AMSR2 brightness temperature RECALIBRATION
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Validation of Chinese HY-2 satellite radar altimeter significant wave height 被引量:10
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作者 YE Xiaomin LIN Mingsen XU Ying 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2015年第5期60-67,共8页
Chinese Haiyang-2(HY-2) satellite is the first Chinese marine dynamic environment satellite. The dual-frequency (Ku and C band) radar altimeter onboard HY-2 has been working effective to provide operational signif... Chinese Haiyang-2(HY-2) satellite is the first Chinese marine dynamic environment satellite. The dual-frequency (Ku and C band) radar altimeter onboard HY-2 has been working effective to provide operational significant wave height (SWH) for more than three years (October 1, 2011 to present).We validated along-track Ku-band SWH data of HY-2 satellite against National Data Buoy Center (NDBC) in-situ measurements over a time period of three years from October 1, 2011 to September 30, 2014, the root mean square error (RMSE) and mean bias of HY-2 SWH is 0.38 m and (-0.13±0.35) m, respectively. We also did cross validation against Jason-2 altimeter SWH data, the RMSE and the mean bias is 0.36m and (-0.22±0.28) m, respectively. In order to compare the statistical results between HY-2 and Jason-2 satellite SWH data, we validated the Jason-2 satellite radar altimeter along-track Ku-band SWH data against NDBC measurements using the same method. The results demonstrate the validation method in this study is scientific and the RMSE and mean bias of Jason-2 SWH data is 0.26 m and (0.00±0.26) m, respectively. We also validated both HY-2 and Jason-2 SWH data every month, the mean bias of Jason-2 SWH data almost equaled to zero all the time, while the mean bias of HY-2 SWH data was no less than -0.31m before April 2013 and dropped to zero after that time. These results indicate that the statistical results for HY-2 altimeter SWH are reliable and HY-2 altimeter along-track SWH data were steady and of high quality in the last three years. The results also indicate that HY-2 SWH data have greatly been improved and have the same accuracy with Jason-2 SWH data after April, 2013. SWH data provided by HY-2 satellite radar altimeter are useful and acceptable for ocean operational applications. 展开更多
关键词 significant wave height VALIDATION Chinese HY-2 satellite radar altimeter
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Assessment of the initial sea surface temperature product of the scanning microwave radiometer aboard on HY-2 satellite 被引量:5
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作者 ZHAO Yili ZHU Jianhua +5 位作者 LIN Mingsen CHEN Chuntao HUANG Xiaoqi WANG He ZHANG Youguang PENG Hailong 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2014年第1期109-113,共5页
HY-2 satellite is the first satellite for dynamic environmental parameters measurement of China,which was launched on 16th August 2011.A scanning microwave radiometer(RM) is carried for sea surface temperature(SST... HY-2 satellite is the first satellite for dynamic environmental parameters measurement of China,which was launched on 16th August 2011.A scanning microwave radiometer(RM) is carried for sea surface temperature(SST),sea surface wind speed,columnar water vapor and columnar cloud liquid water detection.In this paper,the initial SST product of RM was validated with in-situ data of National Data of Buoy Center(NDBC) mooring and Argo buoy.The validation results indicate the accuracy of RM SST is better than 1.7 C.The comparison of RM SST and WindSat SST shows the former is warmer than the latter at high sea surface wind speed and the difference between these SSTs is depend on the sea surface wind speed.Then,the relationship between the errors of RM SST and sea surface wind speed was analyzed using NDBC mooring measurements.Based on the results of assessment and errors analysis,the suggestions of taking account of the affection of sea surface wind speed and using sea surface wind speed and direction derived from the microwave scatteromter aboard on HY-2 for SST product calibration were given for retrieval algorithm improvement. 展开更多
关键词 validation sea surface temperature HY-2 satellite microwave radiometer
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基于Sentinel-2影像东北秋季典型湖泊大气校正方法适用性评价
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作者 李勇 李思佳 +2 位作者 宋开山 徐茂林 刘阁 《地理科学》 CSCD 北大核心 2024年第1期149-158,共10页
本文利用6S(Second Simulation of a Satellite Signal in the Solar Spectrum)、Acolite DSF(Dark spectrum fitting)、C2RCC(Case 2 Regional Coast Color)、SeaDas(SeaWiFS Data Analysis System)、Sen2Cor(Sentinel 2 Correction)、... 本文利用6S(Second Simulation of a Satellite Signal in the Solar Spectrum)、Acolite DSF(Dark spectrum fitting)、C2RCC(Case 2 Regional Coast Color)、SeaDas(SeaWiFS Data Analysis System)、Sen2Cor(Sentinel 2 Correction)、Polymer(Polynomial based algorithm applied to MERIS)和iCOR(Image correction for atmospheric effects)7种大气校正算法,结合松花湖、月亮泡、小兴凯湖实测遥感反射率数据对“哨兵-2号”(Sentinel-2)数据进行大气校正研究,验证算法性能。整体校正结果显示,相较于实测遥感反射率,上述7种大气校正算法均在可见光波段(400~800 nm)呈现不同程度的低估。除C2RCC算法外,其余6种算法校正后的遥感反射率与实测光谱曲线变化趋势基本吻合,其中Sen2Cor算法与iCOR算法性能最佳,Polymer算法性能最差;在单波段校正精度对比中,Sen2Cor和iCOR算法几乎所有波段的均方根误差和平均绝对百分比误差都低于其余5种算法。Sen2Cor算法在560 nm、665 nm和705 nm处校正精度优于其余6种算法,iCOR算法在443 nm和740 nm处有良好的表现,在490 nm处6S算法校正精度最高,拥有最低的均方根误差(0.0059 sr^(−1))和平均绝对百分比误差(21.40%)。结果表明,这7种大气校正算法均可以在一定程度上去除大气影响,增加影像的可用性,Sen2Cor算法和iCOR算法更适用于本文所研究水体或相似水体。 展开更多
关键词 大气校正 Sentinel-2卫星 内陆湖泊水体 遥感反射率
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Ocean Observation from Haiyang Satellites: 2012–2014 被引量:2
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作者 JIANG Xingwei LIN Mingsen 《空间科学学报》 CAS CSCD 北大核心 2014年第5期710-720,共11页
During 2012 and 2014, China has two Haiyang(which means ocean in Chinese, referred to as HY) satellites operating normally in space which are HY-1B and HY-2A. HY-1B is an ocean color environment satellite which was la... During 2012 and 2014, China has two Haiyang(which means ocean in Chinese, referred to as HY) satellites operating normally in space which are HY-1B and HY-2A. HY-1B is an ocean color environment satellite which was launched in April 2007 to observe global ocean color and sea surface temperature, and HY-2A is an ocean dynamic environment satellite which was launched in August 2011 to obtain global marine dynamic environment parameters including sea surface height,significant wave height, ocean wind vectors, etc. Ocean observation data provided by HY-1B and HY-2A have been widely used by both domestic and international users in extensive areas such as ocean environment protection, ocean disaster prevention and reduction, marine environment forecast,ocean resource development and management, ocean investigations and scientific researches, etc. 展开更多
关键词 HY-1B HY-2A OCEAN OBSERVATION satelliteS OCEAN REMOTE SENSING satellite OCEAN applications
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Measurement analyses and evaluations of sea-level heights using the HY-2A satellite’s radar altimeter 被引量:2
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作者 Xingwei Jiang Yongjun Jia Youguang Zhang 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2019年第11期134-139,共6页
The HY-2A satellite is China’s first independent oceanic dynamic environmental satellite,and has been operating continuously for more than six years.The satellite’s radar altimeter,which is one of the main loads on ... The HY-2A satellite is China’s first independent oceanic dynamic environmental satellite,and has been operating continuously for more than six years.The satellite’s radar altimeter,which is one of the main loads on the satellite,has the ability to realize all-weather and all-day observations of global sea-surface heights,as well as significant wave heights and sea-surface wind speeds.These observed data have been widely used in marine disaster prevention and reduction,along with resource development,maritime security and other fields.In order to achieve a comprehensive understanding of the multi-year overall observational performances of the HY-2A satellite’s radar altimeter,all of the observational data of the IGDR product from October 26,2012 to August 27,2017 were selected in this study for a comprehensive evaluation.The height measurement capability of the HY-2A satellite’s radar altimeter was evaluated using self-crossover and Jason-2 crossover methods.The height discrepancies at the self-crossover point of the HY-2A satellite’s ascending and descending orbits were also calculated.It was found that for the HY-2A satellite’s radar altimeter in global waters under the restriction conditions of ascending and descending orbits,the height anomaly differences were within a range of less than 30 cm.The absolute mean error was determined to be 5.81 cm,and the height anomaly standard deviation was 7.76 cm.Under the conditions of the observational areas being limited within a scope of 60°from the Equator,it was determined that the sea-level height anomaly differences were less than 10 cm at the junction of the ascending and descending orbits,the absolute mean error was 3.95 cm.In addition,the sea-level height anomaly standard deviation was observed to be 4.76cm.Using a mutual cross method with the Jason-2 satellite,it was found that under the conditions of the observational area being within the scope of 66°from the equator,the height anomaly differences at the junction were less than 30cm,and the absolute mean error of HY-2A and Jason-2 sea level height anomaly was 5.86 cm,with a standard deviation of 7.52 cm.It was observed that,if within the sea area the sea level height anomaly difference was limited to within 10cm,then the absolute mean error and standard deviation could reach 4.19cm and 4.98cm,respectively.It was confirmed that the HY-2A satellite’s radar altimeter had successfully reached the height measurement level of similar international altimeters.Therefore,it had the ability to meet the needs of marine scientific research and ocean circulation inversions. 展开更多
关键词 HY-2A satellite radar ALTIMETER sea level ANOMALIES
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血清PGE-2、B/A预测急性非静脉曲张性上消化道出血患者预后的价值
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作者 陈德琼 王萍 《现代医药卫生》 2023年第20期3471-3474,3478,共5页
目的 探讨急性非静脉曲张性上消化道出血(ANVUGIB)患者预后的影响因素及血清前列腺素E-2(PGE-2)、血尿素氮与清蛋白(B/A)比值预测其预后的价值。方法 回顾性分析2018年1月至2022年1月武汉市中心医院消化内科收治的150例ANVUGIB患者的临... 目的 探讨急性非静脉曲张性上消化道出血(ANVUGIB)患者预后的影响因素及血清前列腺素E-2(PGE-2)、血尿素氮与清蛋白(B/A)比值预测其预后的价值。方法 回顾性分析2018年1月至2022年1月武汉市中心医院消化内科收治的150例ANVUGIB患者的临床资料,比较死亡组(17例)及存活组(133例)患者一般资料,包含年龄、性别、既往上消化道出血史、平均动脉压、脉率、血红蛋白、清蛋白、血尿素氮、B/A比值、血糖、出血原因、出血次数、Rockall分数、血清PGE-2、血乳酸等,采用单因素和多因素logistic回归研究影响ANVUGIB患者预后的因素,并采用受试者工作特征(ROC)曲线分析血清PGE-2、B/A比值预测患者预后的价值。结果 B/A比值、Rockall分数、出血次数、血清PGE-2、血乳酸均为ANVUGIB患者死亡的相关因素,其中B/A比值、血清PGE-2均为ANVUGIB患者死亡的影响因素,差异均有统计学意义(P<0.05)。血清PGE-2、B/A比值,以及二者联合预测ANVUGIB患者预后的ROC曲线下面积分别为0.877、0.887、0.966。结论 血清PGE-2、B/A比值为影响ANVUGIB患者预后的危险因素,二者联合预测ANVUGIB患者预后具有良好的应用价值,在疾病诊断时临床医师可根据患者各项指标状况进行合理判断。 展开更多
关键词 血清前列腺素e-2 血尿素氮与清蛋白比值 急性非静脉曲张性上消化道出血 影响因素 预后
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Estimation of actual carbon dioxide removal in burned forests using satellite data:A case study in South Korea
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作者 Hanna LEE Gihong KIM 《Journal of Mountain Science》 SCIE CSCD 2023年第4期1051-1060,共10页
With the increasing impact of climate change,carbon emissions and removals have become major issues.Forests are major carbon pools,and forest fires are an essential part of the carbon cycle.This study introduces a mod... With the increasing impact of climate change,carbon emissions and removals have become major issues.Forests are major carbon pools,and forest fires are an essential part of the carbon cycle.This study introduces a model for estimating the detailed actual CO_(2)removal in burned forests using burn severity and tree survivability.Actual CO_(2)removal was estimated from empirical yield tables without using the standard carbon removal provided by the national inventory.The primary CO_(2)calculation method followed the guidelines of the International Panel on Climate Change.The burn severity was mapped using Sentinel-2 multispectral instrument data,and the survivability of each forest type was estimated according to burn severity.The survivability was applied to the pre-fire CO_(2)removal of each forest to estimate post-fire CO_(2)removal.In our case study,the burned forest area was 1,034 ha,and the CO_(2)removal before the fire was 8,615.3t/year.After the fire,removal decreased by 81.2%to 1,618.4 t/yr.In particular,the decrease in coniferous forests was high,more than 86%.The lack of survivability data on burned trees was a major limitation of our study.Systematically accumulating field monitoring data of post-fire forests will be necessary for future research and could serve as a reference for devising immediate countermeasures against forest fires. 展开更多
关键词 Forest fire CO_(2)removal Carbon emission Tree survivability Remote sensing satellite data
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The antioxidant trolox inhibits aging and enhances prostaglandin E-2 secretion in mesenchymal stem cells
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作者 XIAOXU ZHANG LIN ZHANG +5 位作者 LIN DU HUIYAN SUN XIA ZHAO YANG SUN WEI WANG LISHENG WANG 《BIOCELL》 SCIE 2023年第2期385-392,共8页
Mesenchymal stem cells(MSCs)have been widely used in regenerative medicine and clinical therapy due to their capabilities of proliferation,differentiation,and immune regulation.However,during in vitro expansion,MSCs a... Mesenchymal stem cells(MSCs)have been widely used in regenerative medicine and clinical therapy due to their capabilities of proliferation,differentiation,and immune regulation.However,during in vitro expansion,MSCs are prone to aging,which largely limits their application.Prostaglandin E-2(PGE-2)is a key effector secreted by MSCs to exert immunomodulatory effects.By screening the compound library for PGE-2 secretion,the antioxidant trolox was verified as a stimulator of MSCs to secrete PGE-2.The effect of antioxidant trolox on biological characteristics of MSCS,including aging,proliferation,and gene expression,was examined.The results demonstrated that trolox can resist aging,promote proliferation,and enhance PGE-2 secretion of MSCs without affecting their surface marker expression.Furthermore,trolox treatment up-regulates miR-17-92 clusters in MSCs and may contribute to its anti-aging effects.Thus,trolox addition might be beneficial for MSCs expansion and their application. 展开更多
关键词 Mesenchymal stem cells(MSCs) TROLOX ANTIOXIDATION Prostaglandin e-2
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基于卫星遥感的中国人为CO_(2)与大气污染物排放协同关系
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作者 王震山 李新妹 +2 位作者 肖薇 蒋宁萱 柳艺博 《中国环境科学》 EI CAS CSCD 北大核心 2024年第6期3111-3121,共11页
基于多源卫星遥感数据和大气输送模型研究我国人为CO_(2)与大气污染物(NO_(2)和CO)排放协同关系以及新冠疫情管控期间污碳排放变化特征.结果表明:高人为CO_(2)排放对应高浓度的NO_(2)和CO排放,以省级行政区为单位的2018~2020年非生长季X... 基于多源卫星遥感数据和大气输送模型研究我国人为CO_(2)与大气污染物(NO_(2)和CO)排放协同关系以及新冠疫情管控期间污碳排放变化特征.结果表明:高人为CO_(2)排放对应高浓度的NO_(2)和CO排放,以省级行政区为单位的2018~2020年非生长季XCO_(2)异常与XNO_(2)的相关性(r=0.79)高于与XCO的相关性(r=0.61),且高人为CO_(2)排放地区燃烧排放效率更高;2020年2月(疫情管控期)我国XCO_(2)异常、XNO_(2)、XCO下降的区域范围为2019年2月(疫情同比期)面积的50%、70%和49%,2020年2月XCO_(2)异常与XNO_(2)的相关性(r=0.71,P<0.01)高于2019年2月(r=0.59,P<0.01),而XCO_(2)异常与XCO的相关性(r=0.44,P<0.01)低于2019年2月(r=0.68,P<0.01);受大气输送的影响,2020年2月京津冀受西南方向人为排放地区输送的影响高于2019年2月,而长三角受北部长距离输送的影响降低,珠三角受大气输送的影响最小.研究结果表明卫星遥感可有效用于区域污碳协同排放时空变化特征监测. 展开更多
关键词 人为CO_(2)排放 大气污染 协同关系 新冠疫情 卫星遥感
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