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Analysis of the global T_m–T_s correlation and establishment of the latitude-related linear model

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Chinese Science Bulletin 2014年第19期59卷 2340-2347页

作者： Yibin Yao Bao Zhang chaoqian xu Jiajun Chen School of Geodesy and Geomatics Wuhan University

In this study,the correlation between Tm,a key variable in GNSS water vapor inversion,and surface temperature(Ts)was calculated on a global scale based on the global geodetic observing system(GGOS)atmosphere Tmdata and European centre for medium-range weather forecasts(ECMWF)surface temperature *** results show that their correlation is mainly affected by latitudes,and the correlation is stronger at high latitudes and weaker at low *** the correlation is relatively weak in the tropic areas,the temperature changes so little in a year in these areas that we can still achieve good Tmresults by linear regression *** on these facts,‘‘GGOS atmosphere’’Tmdata and ECMWF Tsdata from 2005 to2011 were used to establish the global latitude-related linear regression *** new model has root mean square error(RMSE)of 3.2,3.3,and 4.4 K,respectively,compared with respect to the‘‘GGOS atmosphere’’data,COSMIC data,and radiosonde data and is more accurate than the Bevis Tm–Tsrelationship.

关键词：低纬度地区线性模型全球导航卫星系统线性回归模型均方根误差 ECMWF COSMIC 无线电探空仪

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响水煤矿山体地质灾害实时在线监测技术

能源与环保 2024年第4期46卷 20-25页

作者：何林姚宜斌许超钤何玉峰武汉大学测绘学院湖北武汉430079 贵州盘江煤电集团技术研究院有限公司贵州贵阳550002

为掌握响水煤矿山体地质灾害的实时状态及变化情况,对滑坡体全要素数据进行实时监测,提出了一套基于MEMS三轴加速度传感器和MEMS陀螺仪的山体地质灾害监测技术,介绍了关键技术原理,分析了监测误差的关键参数并建立误差修正模型,制定了... 详细信息

为掌握响水煤矿山体地质灾害的实时状态及变化情况,对滑坡体全要素数据进行实时监测,提出了一套基于MEMS三轴加速度传感器和MEMS陀螺仪的山体地质灾害监测技术,介绍了关键技术原理,分析了监测误差的关键参数并建立误差修正模型,制定了标定试验步骤,在工程案例中对结果进行了验证。工程应用试验结果表明,经过温度误差改正,该系统测量精度可达0.2 mm,分辨率和灵敏性优于0.1 mm,长期稳定性可达0.2 mm,可准确判断山体地质灾害的隐伏滑面为地面下13.0 m处,计算该隐伏滑坡体的方量和下滑力,满足山体地质灾害全要素长期实时监测和预测预警的需要。

关键词：山体地质灾害隐伏滑面 MEMS传感器陀螺仪全要素监测

Carrier phase-based ionospheric observables using PPP models

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Geodesy and Geodynamics 2017年第1期8卷 17-23页

作者： Yan Xiang Yang Gao Junbo Shi chaoqian xu University of Calgary CalgaryCanada Wuhan University Wuhan China

The ionosphere is one of the major error sources in Global Navigation Satellite System （GNSS） posi- tioning, navigation and timing. Estimating the ionospheric delays precisely is of great interest in the GNSS community. To date, GNSS observables for ionospheric estimation are most commonly based on carrier phase smoothed code measurements. However, leveling errors, which affect the performance of ionospheric modeling and differential code bias （DCB） estimation, exist in the carrier phase smoothed code observations. Such leveling errors are caused by the multipath and the short-term variation of DCB. To reduce these leveling errors, this paper investigates and estimates the ionospheric delays based on carrier phase measurements without the leveling errors. The line-of-sight ionospheric observables with high precision are calculated using precise point positioning （PPP） techniques, in which carrier phase measurements are the principal observables. Ionosphere-free and UofC PPP models are applied and compared for their effectiveness to minimize the leveling errors. To assess the leveling errors, single difference of ionospheric observables for a short baseline is examined. Results show that carrier phase- derived ionospheric observables from PPP techniques can effectively reduce the leveling errors. Furthermore, we compared the PPP ionosphere estimation model with the conventional carrier phase smoothed code method to assess the bias consistency and investigate the biases in the ionospheric observables.

关键词： Differential code bias(DCB)Bias consistencyIonospheric observablePrecise point positioning (PPP)Leveling errors

Applicability of Bevis Formula at Different Height Levels and Global Weighted Mean Temperature Model Based on Near-earth Atmospheric Temperature

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Journal of Geodesy and Geoinformation Science 2020年第1期3卷 1-11页

作者： Yibin YAO Zhangyu SUN chaoqian xu School of Geodesy and Geomatics Wuhan UniversityWuhan 430079China

Weighted mean temperature(T m)is a critical parameter in Global Navigation Satellite System(GNSS)technology to retrieve precipitable water vapor(PWV).It is convenient to obtain high-precision T m estimates near surface utilizing Bevis formula and surface ***,some researches pointed out that the Bevis formula has large uncertainties in high-altitude *** investigate the applicability of the Bevis formula at different height levels and find that the Bevis formula has relatively high precision when the altitude is low,while with altitude increasing,the precision decreases *** solve the problem,we analyze the relationship between T m and atmospheric temperature within the near-earth space range(the height range between 0~10 km)and find that they have a high correlation on a global ***,we build a global weighted mean temperature model based on near-earth atmospheric *** results of the model show that this model can provide high-precision T m estimation at any height level in the near-earth space range.

关键词： weighted mean temperature Bevis formula near-earth atmospheric temperature global model

Acetyl salicylic acid attenuates cardiac hypertrophy through Wnt signaling

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Frontiers of Medicine 2015年第4期9卷 444-456页

作者： Samuel Chege Gitau xuelian Li Dandan Zhao Zhenfeng Guo Haihai Liang Ming Qian Lifang Lv Tianshi Li Bozhi xu Zhiguo Wang Yong Zhang chaoqian xu Yanjie Lu Zhiming Du Hongli Shan Baofeng Yang Department of Pharmacology (State-Province Key Laboratories of Biomedicine-Pharmaceutics of China Key Laboratory of Cardiovascular Research Ministry of Education) Harbin Medical University Harbin 150081 China Institute of Cardiovascular Research Harbin Medical University Harbin 150081 China Department of Pharmacy and Complementary Medicine School of Health Sciences Kenyatta University PO. BOX 43844-00100 Nairobi Kenya Institute of Clinical Pharmacy the Second Affiliated Hospital Harbin Medieal University Harbin 150081 China

Ventricular hypertrophy is a powerful and independent predictor of cardiovascular morbid events. The vascular properties of low-dose acetyl salicylic acid （aspirin） provide cardiovascular benefits through the irreversible inhibition of platelet cyclooxygenase 1; however, the possible anti-hypertrophic properties and potential mechanism of aspirin have not been investigated in detail. In this study, healthy wild-type male mice were randomly divided into three groups and subjected to transverse aortic constriction （TAC） or sham operation. The TAC-operated mice were treated with the human equivalent of low-dose aspirin （10 mg·kg^-1· d^-1）; the remaining mice received an equal amount of phosphate buffered saline with 0.65% ethanol, which was used as a vehicle. A cardiomyocyte hypertrophy model induced by angiotensin II （10 nmol· L^-1） was treated with the human equivalent of low （10 or 100μmol·L^-1） and high （1000μmol·L^-1） aspirin concentrations in plasma. Changes in the cardiac structure and function were assessed through echocardiography and transmission electron microscopy. Gene expression was determined through RT-PCR and western blot analysis. Results indicated that aspirin treatment abrogated the increased thickness of the left ventricular anterior and posterior walls, the swelling of mitochondria, and the increased surface area in in vivo and in vitro hypertrophy models. Aspirin also normalized the upregulated hypertrophic biomarkers, p-myosin heavy chain （IS-MHC）, atrial natriuretic peptide （ANP）, and b-type natriuretic peptide （BNP）. Aspirin efficiently reversed the upregulation of β-catenin and P-Akt expression and the TAC- or ANG II-induced downregulation of GSK-3~. Therefore, low-dose aspirin possesses significant anti-hypertrophic properties at clinically relevant concentrations for anti-thrombotic therapy. The downregulation of β-catenin and Akt may be the underlying signaling mechanism of the effects of aspirin.

关键词： aspirin Akt cardiac hypertrophy GSK-3β Wnt/β-catenin

LncRNA CFAR promotes cardiac fibrosis via the miR-449a-5p/LOXL3/mTOR axis

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Science China(Life Sciences) 2023年第4期66卷 783-799页

作者： Mingyu Zhang Bowen Zhang Xiaohan Wang Jiahang Song Ming Tong Zheng Dong Jiaonan xu Meng Liu Yuan Jiang Ning Wang Ying Wang Zhimin Du Yanyan Liu Rong Zhang chaoqian xu Department of Pharmacology State-Province Key Laboratories of Biomedicine-Pharmaceutics of ChinaKey Laboratory of Cardiovascular Medicine ResearchMinistry of EducationCollege of PharmacyHarbin Medical UniversityHarbin 150081China Department of Pharmacy The Second Affiliated Hospital of Harbin Medical UniversityHarbin 150081China Institute of Clinical Pharmacy The Second Affiliated Hospital of Harbin Medical UniversityHarbin 150081China Zhuhai People’s Hospital Guangdong Provincial Key Laboratory of Tumor Interventional Diagnosis and TreatmentZhuhai Hospital Affiliated with Jinan UniversityJinan UniversityZhuhai 519000China Center of Chronic Diseases and Drug Research of Mudanjiang Medical University Mudanjiang 157011China

Cardiac fibrosis is one of the crucial pathological factors in the heart,and various cardiac conditions associated with excessive fibrosis can eventually lead to heart ***,the exact molecular mechanism of cardiac fibrosis remains *** the present study,we show that a novel lnc RNA that we named cardiac fibrosis-associated regulator(CFAR)is a profibrotic factor in the *** was upregulated in cardiac fibrosis and its knockdown attenuated the expression of fibrotic marker genes and the proliferation of cardiac fibroblasts,thereby ameliorating cardiac ***,CFAR acted as a ce RNA sponge for mi R-449a-5p and derepressed the expression of LOXL3,which we experimentally established as a target gene of mi *** contrast to CFAR,mi R-449a-5p was found to be significantly downregulated in cardiac fibrosis,and artificial knockdown of mi R-449a-5p exacerbated fibrogenesis,whereas overexpression of mi R-449a-5p impeded ***,we found that LOXL3 mimicked the fibrotic factor TGF-β1 to promote cardiac fibrosis by activating m ***,our study established CFAR as a new profibrotic factor acting through a novel mi R-449a-5p/LOXL3/m TOR axis in the heart and therefore might be considered as a potential molecular target for the treatment of cardiac fibrosis and associated heart diseases.

关键词： CFAR miR-449a-5p LOXL3 mTOR cardiac fibrosis

基于SPEI指数的河北省夏秋两季干旱预测研究

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科学技术创新 2024年第8期 70-73页

作者：张冉王海兴张照娜陆禹阔史东旭许超前贾悦河北水利电力学院遥感与智慧水利创新中心河北沧州

为获得河北省夏、秋两季干旱预测模型,本文以标准化降雨蒸散指数(SPEI)为基础,基于极限学习机模型(ELM),采用麻雀搜索算法(SSA)、蜂群算法(ABC)、蝙蝠算法(BA)、粒子群算法(PSO)、遗传算法(GA)共5种优化算法构建了优化ELM模型用于建立区... 详细信息

为获得河北省夏、秋两季干旱预测模型,本文以标准化降雨蒸散指数(SPEI)为基础,基于极限学习机模型(ELM),采用麻雀搜索算法(SSA)、蜂群算法(ABC)、蝙蝠算法(BA)、粒子群算法(PSO)、遗传算法(GA)共5种优化算法构建了优化ELM模型用于建立区域SPEI指数估算模型,结果表面:SSA-ELM模型在所有模型中精度最高,同时可移植性较好,可作为河北省夏、秋两季的干旱预测模型使用。

关键词：河北省标准化降雨蒸散指数极限学习机模型麻雀搜索算法模型可移植性

The Research on Four-dimensional Water Vapor Tomography Based on Real-time PPP Technique

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The Research on Four-dimensional Water Vapor Tomography Base...

第七届中国卫星导航学术年会

作者： Qingzhi Zhao Yibin Yao chaoqian xu School of geodesy and geomatics Wuhan University

With the development of International GNSS Service(IGS) real-time pilot project(RTPP),acquiring Precipitable Water Vapor(PWV) with high accuracy has become a reality based on the real-time Precise Point Pointing(RT-PPP) technique. The accuracy of Zenith Total Delay(ZTD) and PWV derived from RT-PPP have been validated using observed Global Positioning System(GPS) data and meteorology data from Satellite Positioning Reference Station Network(SatR ef) in 2014. The ZTD comparison with that from afterwards PPP and GAMIT software shows that the relative coefficients are 0.9786 and 0.9687,respectively. The PWV comparison with that from radiosonde shows that the relative coefficient and RMS are 0.9512 and 2.13 mm,respectively. It is a clear evidence that the RT-PPP technique has a similar accuracy with the result calculated using afterwards IGS products. However,PWV is a mean of water vapor information of many GNSS signal rays during a period of time over the station,which cannot reflect the three-dimensional water vapor distribution. Slant Water Vapor(SWV)can be obtained by mapping PWV at different elevation and azimuth angles. The tomographic experiment has been performed using SWVs of twelve station from SatR ef as tomographic observation and compared with result from radiosonde. The comparison shows a good agreement and the RMS,SD,Bias and MAE of Integrated Water Vapor(IWV) are 3.60 mm,2.78 mm,2.29 mm and 2.92 mm,respectively,the Root Mean Square(RMS),Standard Deviation(SD),Bias and Mean Absolute Error(MAE) of calculated water vapor density are 1.08 g/m,1.03 g/m,-0.21 g/m and 0.77 g/m,respectively. The above result makes it possible that acquiring the real-time three-dimensional water vapor distribution using tomography approach with SWVs derived from RT-PPP technique,which has an important influence on short-term disastrous weather and now-casting precipitation forecasting.

关键词： IGS Real-time pilot project Real-time PPP technique Slant water vapor Tomography approach

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一种可用于估计全球水汽标高的经验模型

测绘学报 2015年第10期44卷 1085-1091,1151页

作者：张豹姚宜斌许超钤武汉大学测绘学院湖北武汉430079 武汉大学地球空间环境与大地测量教育部重点实验室湖北武汉430079 地球空间信息技术协同创新中心湖北武汉430079

水汽标高是一个反映水汽垂直分布特征的参数,也是全球导航卫星系统(global navigation satellite system,GNSS)对流层天顶湿延迟改正和GNSS水汽层析中的一个辅助参数。本文对2006—2012年水汽标高的时间序列进行频谱分析,发现水汽标高... 详细信息

水汽标高是一个反映水汽垂直分布特征的参数,也是全球导航卫星系统(global navigation satellite system,GNSS)对流层天顶湿延迟改正和GNSS水汽层析中的一个辅助参数。本文对2006—2012年水汽标高的时间序列进行频谱分析,发现水汽标高在时间上呈现出年周期和半年周期变化,因此利用包含年周期和半年周期的三角函数来表达水汽的时变规律,然后利用欧洲中尺度天气预报中心(European Centre for Medium-range Weather Forecasting,ECMWF)的数据在全球1°×1°的格网点上分别拟合了三角函数的系数。通过上述方法首次构建了一个全球适用的水汽标高模型GSH,该模型既体现了水汽标高的时变特性又考虑了其地理差异。以无线电探空数据为参考,GSH具有-0.19km的偏差(bias)和1.81km的均方根误差(root mean square error,RMSE);以ECMWF数据为参考,GSH具有0.04km的bias和1.52km的RMSE。GSH整体上表现出了比较稳定的精度,可服务于GNSS气象学研究,也可为其他相关气象研究提供水汽标高参考。

关键词：水汽标高 GSH模型水汽