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LEO satellite clock analysis and prediction for positioning applications

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Geo-Spatial Information Science 2022年第1期25卷 14-33页

作者： kan Wang Ahmed El-Mowafy School of Earth and Planetary Sciences Curtin UniversityPerthAustralia

The positioning service aided by low Earth orbit(LEO)mega-constellations has become a hot topic in recent *** achieve precise positioning,accuracy of the LEO clocks is important for single-receiver *** bridge the gap between the applicable time of the clock products and the time of positioning,the precise LEO clocks need to be predicted over a certain period depending on the sampling interval of the clock *** study discusses the prediction errors for periods from 10 s to 1 h for two typical LEO clock types,*** ultra-stable oscillator(USO)and the oven-controlled crystal oscillator(OCXO).The prediction is based on GNSS-determined precise clock estimates,where the clock stability is related to the GNSS estimation errors,the behaviors of the oscillators themselves,the systematic effects related to the environment and the relativistic effects,and the stability of the time *** on real data analysis,LEO clocks of the two different types are simulated under different conditions,and a prediction model considering the systematic effects is *** to a simple polynomial fitting model usually applied,the proposed model can significantly reduce the prediction errors,*** about 40%-70%in simulations and about 5%-30%for real data containing different miss-modeled *** both clock types,short-term prediction of 1 min would result in a root mean square error(RMSE)of a few centimeters when using a very stable time *** RMSE amounts to about 0.1 m,when a typical real-time time reference of the national center for space studies(CNES)real-time clocks was *** long-term prediction of 1 h,the RMSE could range from below 1 m to a few meters for the USOs,depending on the complexity of the miss-modeled *** OCXOs,the 1 h prediction could lead to larger errors with an RMSE of about 10 m.

关键词： LEO clock prediction USO OCXO relativistic effects

Structure, Performance, and Application of BiFeO_(3) Nanomaterials

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Nano-Micro Letters 2020年第6期12卷 214-236页

作者： Nan Wang Xudong Luo Lu han Zhiqiang Zhang Renyun Zhang h-kan Olin Ya Yang CAS Center for Excellence in Nanoscience Beijing Key Laboratory of Micronano Energy and SensorBeijing Institute of Nanoenergy and NanosystemsChinese Academy of SciencesBeijing 100083People’s Republic of China School of Materials and Metallurgy University of Science and Technology Liaoning185 Qianshan Zhong RoadAnshan 114051LiaoningPeople’s Republic of China School of Chemical Engineering University of Science and Technology Liaoning185 Qianshan Zhong RoadAnshan 114051LiaoningPeople’s Republic of China Department of Natural Sciences Mid Sweden UniversityHolmgatan 1085170 SundsvallSweden School of Nanoscience and Technology University of Chinese Academy of SciencesBeijing 100049People’s Republic of China Center on Nanoenergy Research School of Physical Science and TechnologyGuangxi UniversityNanning 530004GuangxiPeople’s Republic of China

Multiferroic nanomaterials have attracted great interest due to simultaneous two or more properties such as ferroelectricity,ferromagnetism,and ferroelasticity,which can promise a broad application in multifunctional,lowpower consumption,environmentally friendly *** ferrite(BiFeO3,BFO)exhibits both(anti)ferromagnetic and ferroelectric properties at room ***,it has played an increasingly important role in multiferroic *** this review,we systematically discussed the developments of BFO nanomaterials including morphology,structures,properties,and potential applications in multiferroic devices with novel *** the opportunities and challenges were all analyzed and *** hope this review can act as an updating and encourage more researchers to push on the development of BFO nanomaterials in the future.

关键词： Bismuth ferrite Multiferroic nanomaterials Multifunctional device Ferroelectricity Magnetoelectric coupling

Laser-Etched Stretchable Graphene-Polymer Composite Array for Sensitive Strain and Viscosity Sensors

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Nano-Micro Letters 2019年第4期11卷 709-719页

作者： Yuting Jiang Yang Wang heting Wu Yuanhao Wang Renyun Zhang h?kan Olin Ya Yang CAS Center for Excellence in Nanoscience Beijing Key Laboratory of Micro-nano Energy and SensorBeijing Institute of Nanoenergy and NanosystemsChinese Academy of SciencesBeijing 100083People’s Republic of China Xinjiang Technical Institute of Physics and Chemistry Chinese Academy of SciencesUrumqiXinjiang 830011People’s Republic of China Department of Natural Sciences Mid Sweden UniversityHolmgatan 1085170 SundsvallSweden School of Nanoscience and Technology University of Chinese Academy of SciencesBeijing 100049People’s Republic of China Center on Nanoenergy Research School of Physical Science and TechnologyGuangxi UniversityNanning 530004People’s Republic of China

The ability to control surface wettability and liquid spreading on textured surfaces is of interest for extensive *** materials have prominent advantages for producing the smart coatings with multiple functions for strain ***,we report a simple method to prepare flexible hydrophobic smart coatings using graphene-polymer *** of individual patterns in the films were created by laser engraving and controlled the contact angle of small drops by pinning the contact lines in a horizontal tensile range of 0-200%.By means of experiments and model,we demonstrate that the ductility of drops is relied on the height-to-spacing ratio of the individual pattern and the intrinsic contact ***,the change of drop size was utilized to measure the applied strain and liquid viscosity,enabling a strain sensitivity as high as 1068μm2/%.The proposed laser-etched stretchable graphene-polymer composite has potential applications in DNA microarrays,biological assays,soft robots,and so on.

关键词： hydrophobic smart coatings Flexible sensors Soft materials Controlled drops Graphene

慢性肌筋膜触发点模型大鼠的尿液代谢组学分析

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中国组织工程研究 2025年第8期29卷 1585-1592页

作者：刘琳刘世轩陆馨悦王侃南京体育学院运动健康学院江苏省南京市210014

背景:慢性肌筋膜触发点通过非靶向代谢组学技术可识别差异性代谢物变化,有助于从内源性小分子代谢物层面理解并进一步探究慢性肌筋膜触发点的病理生理过程和发病机制。目的:以慢性肌筋膜触发点模型大鼠为研究对象,基于尿液代谢组学寻找... 详细信息

背景:慢性肌筋膜触发点通过非靶向代谢组学技术可识别差异性代谢物变化,有助于从内源性小分子代谢物层面理解并进一步探究慢性肌筋膜触发点的病理生理过程和发病机制。目的:以慢性肌筋膜触发点模型大鼠为研究对象,基于尿液代谢组学寻找潜在生物标志物及相关代谢通路。方法:将16只SD大鼠随机分为造模组和正常组,造模组大鼠采用钝性打击结合离心运动(跑台坡度为-16°,跑速为16 m/min,训练时间为90 min/次)方式建立慢性肌筋膜触发点动物模型,每周1次,连续干预8周,休息4周;正常组大鼠不做干预。12周造模结束后,采用代谢笼法收集大鼠造模后24 h尿液,利用液相色谱-质谱联用非靶向代谢组学技术对尿样进行代谢图谱检测,筛选出共同差异代谢物,并进行生物信息学分析。结果与结论:①与正常组相比,造模组有32个差异代谢标志物,其中上调21个、下调11个;依据变量权重值>3,共14个差异代谢物被认定为潜在生物标志物;②京都基因与基因组百科全书富集分析表明,慢性肌筋膜触发点的形成与初级胆汁酸生物合成、花生四烯酸代谢通路密切相关。

关键词：肌筋膜触发点大鼠尿液代谢组学生物信息学生物标志物差异代谢物代谢笼法运动损伤

Validation of atmospheric chemistry measurements from MIPAS,SCIAMAChY,GOMOS onboard ENVISAT by observations of balloon-borne MIPAS-B

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Science China Earth Sciences 2010年第10期53卷 1533-1541页

作者： WETZEL G OELhAF h FRIEDL-VALLON F KLEINERT A LENGEL A MAUChER G NORDMEYER h GRUNOW K fischer h Institute for Meteorology and Climate Research(IMK) Karlsruhe Institute of Technology(KIT) Senate Department for health Environment and Consumer Protection

In order to validate the atmospheric chemistry measurements by MIPAS,SCIAMAChY,and GOMOS onboard the ENVISAT,three flights of the balloon-borne Michelson Interferometer for Passive Sounding(MIPAS-B) were carried out in 2002 and 2003 at Aire sur l'Adour(France 44°N,0°E) and Esrange,Kiruna(Sweden 68°N,21°E).The validation campaign activities are summarized in this *** MIPAS-B instrument and its data processing procedure as well as the validation approaches are discussed in *** satellite and balloon measurements are matched with high coincidence in time and space,allowing a coincident approach to be applied for their ***,a trajectory model is used to confirm and enhance the statistical significance of the *** validation results show that MIPAS measurements of accuracy for temperature,h2O,O3,hNO3,Ch4,N2O,and NO2 are good in the altitude range of 8-39 km(No2,22-39 km).And the precision is good between the altitudes of 15-33 km(No2,22-23 km).however,some exceptions were also found for temperature,h2O,hNO3,and *** SCIAMAChY data of accuracy for O3 and NO2 are within expectations between the altitudes 9-38 km except for O3 in 28-38 *** GOMOS data about O3 and NO2 are promising according to the preliminary comparison results.

关键词： validation ENVISAT MIPAS SCIAMAChY GOMOS MIPAS-B

On the relationship between plant species diversity and genetic diversity of Plantago lanceolata(Plantaginaceae)within and between grassland communities

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Journal of Plant Ecology 2010年第1期3卷 41-48页

作者： Nidal Odat Frank h.hellwig Gottfried Jetschke Markus fischer Institute of Ecology Friedrich-Schiller-UniversityDornburger Straße 15907743 JenaGermany Department of Biology Al-Hussein Bin Talal UniversityPO Box 20Ma’anJordan Institute of Systematic Botany Friedrich-Schiller-UniversityPhilosophenweg 16D-07743 JenaGermany Institute of Plant Sciences University of BernAltenbergrain 21CH-3013 BernSwitzerland

Aims and Methods The relationship between genetic diversity and species diversity and the underlying mechanisms are of both fundamental and applied *** used amplified fragment length polymorphism(AFLP)and vegetation records to investigate the association between genetic diversity of Plantago lanceolata and plant species diversity using 15 grassland communities in central *** used correlation and partial correlation analyses to examine whether relationships between genetic and species diversity were direct or mediated by environmental differences between *** Findings Both within-and between-population genetic diversity of *** were significantly positively correlated with plant species diversity within and between *** and partial correlations revealed that the positive correlations indirectly resulted from the effects of abiotic habitat characteristics on plant species diversity and,via abundance,on genetic diversity of ***,they did not reflect a direct causal relationship between plant species diversity and genetic diversity of ***,as would have been expected based on the hypothesis of a positive relationship between plant species diversity and niche diversity.

关键词： diversity biodiversity conservation ecological niche genetic diversity species richness

Calibration of Gridded Wind Speed Forecasts Based on Deep Learning

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Journal of Meteorological Research 2023年第6期37卷 757-774页

作者： Xuan YANG kan DAI Yuejian ZhU National Meteorological Centre Beijing100081China NOAA/NWS/NCEP/Environmental Modeling Center College ParkMaryland20740USA

The challenges of applying deep learning(DL) to correct deterministic numerical weather prediction(NWP) biases with non-Gaussian distributions are discussed in this *** is known that the DL UNet model is incapable of correcting the bias of strong winds with the traditional loss functions such as the MSE(mean square error),MAE(mean absolute error),and WMAE(weighted mean absolute error).To solve this,a new loss function embedded with a physical constraint called MAE_MR(miss ratio) is *** performance of the UNet model with MAE_MR is compared to UNet traditional loss functions,and statistical post-processing methods like Kalman filter(KF) and the machine learning methods like random forest(RF) in correcting wind speed biases in gridded forecasts from the ECMWF high-resolution model(hRES) in East China for lead times of 1–7 *** addition to MAE for full wind speed,wind force scales based on the Beaufort scale are derived and *** to raw hRES winds,the MAE of winds corrected by UNet(MAE_MR) improves by 22.8% on average at 24–168 h,while UNet(MAE),UNet(WMAE),UNet(MSE),RF,and KF improve by 18.9%,18.9%,17.9%,13.8%,and 4.3%,*** with MSE,MAE,and WMAE shows good correction for wind forces 1–3 and 4,but negative correction for 6 or ***(MAE_MR) overcomes this,improving accuracy for forces 1–3,4,5,and 6 or higher by 11.7%,16.9%,11.6%,and 6.4% over hRES.A case study of a strong wind event further shows UNet(MAE_MR) outperforms traditional post-processing in correcting strong wind biases.

关键词： deep learning wind speed grid forecasting loss function statistical post-processing

Inter-and intramolecular adhesion mechanisms of mussel foot proteins

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Science China(Technological Sciences) 2020年第9期63卷 1675-1698页

作者： kan YaJing WEI ZhiYong TAN QiYan ChEN YunFei Jiangsu Key Laboratory for Design and Manugacture of Micro-Nano Biomedical Iastruments and School of Mchanical Enginering.Southeast UniversityNanjing 211189China School of Mechanical Engineering Nanjing Institute of TechnologyNanjing 211167China

Mussel foot proteins(Mfps) secreted in the byssal plaque of marine mussels are widely researched for their relevance to mussel adhesion in water. As the abundant residue in the amino acid sequences of major adhesive proteins, 3,4-dihydroxyphenylalanine(Dopa) or its catecholic moiety plays a key role in both Mfp binding to surface and cohesive cross-linking of Mfps in byssal plaques. The binding performance of an Mfp significantly depends on the content and redox state of Dopa, whereas the types of interaction vary in line with different surface chemistries and p h conditions. Thorough understanding of mussel adhesion from a molecular perspective is crucial to promote the application of synthetic mussel-bionic adhesives. This article presents a brief review of the research progress on the adhesion mechanisms of Mfps, which further emphasizes the contributions of Dopamediated interactions and considers other amino acids and factors. The involved inter-and intramolecular interactions are responsible for not only the diverse adhesion capacities of an adhesive byssal plaque as mussel's adhesion precursor but also the formation and properties of the plaque structure.

关键词： mussel foot protein adhesion mechanism Dopa catechol surface forces apparatus

Synthesis and Crystal Structure of Copper(II) Complex with Mixed Bipyridine and 2-hydroxy-1-naphthaldehyde Ligands

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Chinese Journal of Structural Chemistry 2002年第1期21卷 13-16页

作者： BUPing－Yu YAOXin－kan 等 Department of Chemistry Nankai University 天津 300071 Central Laboratory Nankai University 天津 300071

A mononuclear copper(II) complex, [Cu(bipy)(naph)(ClO4)] (where bipy is bipyridine and naph is 2-hydroxy-1-naphthaldehyde), was synthesized and characterized by X-ray single-crystal structure analysis. The crystal is triclinic, space group P ?with a = 9.245(4), b = 9.962(4), c = 10.809(7) ? a = 84.83(5), b =82.35(4), g = 81.02(4), V = 972.1 ?, C21h15ClCuN2O6 Mr = 490.36, Z = 2, F(000) = 498, Dx = 1.68 g/cm3, m = 13.05 cm-1, R = 0.078, Rw = 0.081 for 2295 observed reflections with I > 3s(I). The copper(II) ion is coordinated by two nitrogen atoms of bipy and two oxygen atoms of naph in the equatorial plane, with an axial perchlorate oxygen-copper(II) bond to copper(II) ion to form square-pyramidal coordination geometry. The coordination environment of copper(II) is similar to the active site of galactose oxidase and this compound may also be considered as the structural model of galactose oxidase.

关键词： copper complex crystal structure galactose oxidase