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Typhoon Track Forecast with a Hybrid GSI-ETKF Data Assimilation System

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Atmospheric and Oceanic Science Letters 2013年第3期6卷 161-166页

作者： LUO Jing-Yao CHEN Bao-De LI Hong fan guang-zhou WANG Xiao-Feng College of Atmospheric Sciences Chengdu University of Informational Technology Shanghai Typhoon Institute China Meteorological Administration (CMA)

A hybrid grid-point statistical interpolation-ensemble transform Kalman filter (GSI-ETKF) data assimilation system for the Weather Research and Forecasting (WRF) model was developed and applied to typhoon track forecast with simulated dropsonde observations. This hybrid system showed significantly improved results with respect to tropical cyclone track forecast compared to the standard GSI system in the case of Muifa in 2011. Further analyses revealed that the flow-dependent ensemble covariance was the major contributor to the better performance of the GSI-ETKF system than the standard GSI system; the GSI-ETKF system was found to be potentially able to adjust the position of the typhoon vortex systematically and better update the environmental field.

关键词： data assimilation hybrid tropical cyclone flow-dependent

Changes to the Natural Regional Boundaries in China During 1961-2007

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Atmospheric and Oceanic Science Letters 2011年第4期4卷 199-203页

作者： YU Zhen-Yan fan guang-zhou DONG Yi-Ping WANG Lei HUA Wei zhou Ding-Wen Zhejiang Climate Center Hangzhou 310017 China College of Atmospheric Sciences Chengdu University of Information Technology （CULT） Chengdu 610225 China

Daily temperature data from 599 stations across China for the years 1961 to 2007 were used to analyze the changes in the natural regional boundaries. The results show that the accumulated temperature ≥10℃ and its duration changed dramatically from the end of 1990s to the early 21 st century. The amplitude of natural regional boundaries was greater in the 21st century than it was in the 20th century. In the eastern region of China, the climatic zones were migrating generally northward, with the northern edge of the subtropical zone and the eastern section of the warm temperate zone showing an obvious northward shift of up to 1-3° of latitude. The climatic zones moved south in the Qinghal-Tibet Plateau, western Inner Mongolia, and some areas of western Xinjiang, and slightly to the north in other parts of the western region.

关键词： accumulated temperature duration natural regional boundary global warming

Derivatives of Intersection Local Time for Two Independent Symmetricα-stable Processes

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Acta Mathematica Sinica,English Series 2024年第5期40卷 1273-1292页

作者： Huan zhou guang Jun SHEN Qian YU Department of Mathematics Anhui Normal UniversityWuhu 241002P.R.China Department of Mathematics Nanjing University of Aeronautics and AstronauticsNanjing 211106P.R.China Key Laboratory of Mathematical Modelling and High Performance Computing of Air Vehicles(NUAA) MIITNanjing 211106P.R.China

In this paper,we consider the derivatives of intersection local time for two independent d-dimensional symmetricα-stable processes X^(α) and X^(α)with respective indices α and α.We first study the sufficient condition for the existence of the derivatives,which makes us obtain the exponential integrability and H?lder *** we show that this condition is also necessary for the existence of derivatives of intersection local time at the ***,we also study the power variation of the derivatives.

关键词： Symmetric stable processes intersection local time exponential integrability power variation

Resolution Enhancement of SOHO/MDI Magnetograms

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Research in Astronomy and Astrophysics 2024年第6期24卷 358-367页

作者： Ying Qin Kai-fan Ji Hui Liu Xiao-guang Yu Yunnan Observatories Chinese Academy of SciencesKunming 650011China University of Chinese Academy of Sciences Beijing 100049China Yunnan Key Laboratory of Solar Physics and Space Science Kunming 650216China Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of SciencesKunming 650216China

Research on the solar magnetic field and its effects on solar dynamo mechanisms and space weather events has benefited from the continual improvements in instrument resolution and measurement *** augmentation and assimilation of historical observational data timelines also play a significant role in understanding the patterns of solar magnetic field *** the realm of astronomical data processing,super-resolution(SR)reconstruction refers to the process of using a substantial corpus of training data to learn the nonlinear mapping between low-resolution(LR)and high-resolution(HR)images,thereby achieving higherresolution astronomical *** paper is an application study in high-dimensional nonlinear *** learning models were employed to perform SR modeling on SOHO/MDI magnetograms and SDO/HMI magnetograms,thus reliably achieving resolution enhancement of full-disk SOHO/MDI magnetograms and enhancing the image resolution to obtain more detailed *** this study,a data set comprising 9717pairs of data from 2010 April to 2011 February was used as the training set,1332 pairs from 2011 March were used as the validation set and 1034 pairs from 2011 April were used as the test *** data preprocessing,we randomly cropped 128×128 sub-images as the LR cases from the full-disk MDI magnetograms,and the corresponding 512×512 sub-images as HR ones from the HMI full-disk magnetograms for model *** tests conducted have shown that the study successfully produced reliable 4×SR reconstruction of full-disk MDI *** MESR model's results(0.911)were highly correlated with the target HMI magnetographs as indicated by the correlation coefficient ***,the method achieved the best PSNR,SSIM,MAE and RMSE values,indicating that the MESR model can effectively reconstruct magnetograms.

关键词： magnetic fields techniques:image processing virtual observatory tools Sun:magnetic fields

Review of Fiber-Optic Localized Surface Plasmon Resonance Sensors:Geometries,Fabrication Technologies,and Bio-Applications

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Photonic Sensors 2024年第2期14卷 31-56页

作者： Mengdi LU Chen WANG Ruizhi fan Ming LIN Jianye guang Wei PENG Affiliated Cancer Hospital Dalian University of TechnologyShenyang 110042China School of Physics Dalian University of TechnologyDalian 116024China

Localized surface plasmon resonance(LSPR)biosensors,which enable nanoscale confinement and manipulation of light,offer the enhanced sensitivity and electromagnetic energy *** integration of LSPR with the fiber-optic technology has led to the development of compact and versatile sensors for miniaturization and remote *** comprehensive review explores various sensor configurations,fiber types,and geometric shapes,highlighting their benefits in terms of sensitivity,integration,and performance *** techniques such as focused non-chemical bonding strategies and self-assembly of nanoparticles are discussed,providing control over nanostructure morphology and enhancing sensor ***-applications of fiber-optic LSPR(FOLSPR)sensors are detailed,specifically in biomolecular interactions and analysis of proteins,pathogens and cells,nucleic acids(DNA and RNA),and other small molecules(organic compounds and heavy metal ions).Surface modification and detection schemes are emphasized for their potential for label-free and real-time *** challenges and prospects of FOLSPR sensors are addressed,including the developments in sensitivity,fabrication techniques,and measurement *** with emerging technologies such as nanomaterials is highlighted as a promising direction for future ***,this review provides insights into the advancements and potential applications of FOLSPR sensors,paving the way for sensitive and versatile optical biosensing platforms in various fields.

关键词： Fiber-optic localized surface plasmon resonance biosensor nanoparticles geometric configuration fabrication technology

Characteristics of complex air pollution in typical cities of North China

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Atmospheric and Oceanic Science Letters 2018年第1期11卷 29-36页

作者： TANG Bin-Yan XIN Jin-Yuan GAO Wen-Kang SHAO Ping SU Hong-Juan WEN Tian-Xue SONG tao fan guang-zhou WANG Shi-Gong plateau Atmosphere and Environment Key Laboratory of Sichuan Province ＆ College of Atmospheric Sciences Chengdu University of Information Technology Chengdu China State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry Institute of Atmospheric Physics Chinese Academy of Sciences Beijing China Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters Nanjing University of Information Science ＆Technology Nanjing China

The Beijing-Tianjin-Hebei urban agglomeration is currently facing severe complex air pollution. In this paper, simultaneous observations conducted in 2014 show that the annual mean concentration of fine particulate matter （PM2.5） was 84 ± 70, 86 ±60, and 118 ± 95 μg m-3 in Beijing, Tianjin, and Shijiazhuang, respectively. The mean 03 8h max in the summer was 171 ± 43, 147 ± 45, and 146 ± 44 μg m-3, respectively. This research indicates that PM2.5 and O3 are positively correlated when the temperature exceeds 20 ℃5 and the urban agglomeration shows characteristics of complex air pollution consisting of superimposed 03 and PM2.s. In summer, when the humidity was less than 55%, secondary particles and 03 also increased in a coordinated manner （y = 1.35x ＋ 29.85; R2 = 0.61）, which demonstrates severe complex pollution. However, the mean PM2.5（y） and mean 03 8 h max （x） in summer showed a negative correlation （y = - 1.3x ＋ 245; R2 = 0.61 ） in the three regions, indicating high concentrations of PM2.5 pollution partially inhibit O3 generation.

关键词： O3 PM2.5 PM10 complex airpollution Beijing-Tianjin-Hebei urban agglomeration

Subclinical impairment of left ventricular myocardium function in type 2 diabetes mellitus patients with or without hypertension

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World Journal of Diabetes 2024年第6期15卷 1272-1279页

作者： Zeng-guang Chen guang-An Li Jun Huang Li fan Department of Cardiology The Affiliated Changzhou Second People’s Hospital with Nanjing Medical UniversityChangzhou 213000Jiangsu ProvinceChina Department of Echocardiography The Affiliated Changzhou Second People’s Hospital with Nanjing Medical UniversityChangzhou 213000Jiangsu ProvinceChina

BACKGROUND Cardiovascular disease has been the leading cause of morbidity and mortality for type 2 diabetes mellitus(T2DM)patients over the last *** To determine whether layer-specific global longitudinal strain(GLS)combined with peak strain dispersion(PSD)can be used to assess left ventricle(LV)myocardium systolic dysfunction in T2DM patients or without hypertension(HP).METHODS We enrolled 97 T2DM patients,70 T2DM+HP patients and 101 healthy ***-specific GLS and PSD were calculated by EchoPAC software in apical three-,four-and two-chamber *** of the epimyocardial,middle-layer and endomyocardial(GLSepi,GLSmid,and GLSendo)were measured and *** operating characteristic analysis was performed to detect LV myocardium systolic dysfunction in T2DM *** There were significant differences in GLSepi,GLSmid,GLSendo,and PSD between healthy subjects,T2DM patients and T2DM patients with HP(PT2DM patients>T2DM with HP patients in the absolute values of GLSepi,GLSmid and GLSendo(P<0.001),while PSD was ranked healthy subjects

关键词： Type 2 diabetes mellitus Hypertension Speckle tracking echocardiography Global longitudinal strain Peak strain dispersion

Evaluation of left ventricular systolic function in type 2 diabetes mellitus patients with and without peripheral vascular disease

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World Journal of Diabetes 2024年第6期15卷 1280-1290页

作者： guang-An Li Jun Huang Li fan Department of Echocardiography The Affiliated Changzhou Second People’s Hospital with Nanjing Medical UniversityChangzhou 213000Jiangsu ProvinceChina

BACKGROUND Peripheral vascular disease(PVD)is a common complication of type 2 diabetes mellitus(T2DM).Patients with T2DM have twice the risk of PVD as nondiabetic *** To evaluate left ventricular(LV)systolic function by layer-specific global longitudinal strain(GLS)and peak strain dispersion(PSD)in T2DM patients with and without *** Sixty-five T2DM patients without PVD,57 T2DM patients with PVD and 63 normal controls were enrolled in the ***-specific GLS[GLS of the epimyocardium(GLSepi),GLS of the middle myocardium(GLSmid)and GLS of the endocardium(GLSendo)]and PSD were *** operating characteristic(ROC)analysis was performed to calculate the sensitivity and specificity of LV systolic dysfunction in T2DM patients with *** calculated Pearson’s correlation coefficients between biochemical data,echocardiographic characteristics,and layer-specific GLS and *** There were significant differences in GLSepi,GLSmid and GLSendo between normal controls,T2DM patients without PVD and T2DM patients with PVD(PT2DM patients without PVD>T2DM patients with PVD in the absolute value of GLS(P<0.001).PSD differed significantly between the three groups,and the trend ranking was as follows:normal controls

关键词： Type 2 diabetes mellitus Peripheral vascular disease Speckle tracking echocardiography Global longitudinal strain Peak strain dispersion

Prescribed time control based on the periodic delayed sliding mode surface without singularities

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Science China(Information Sciences) 2024年第7期67卷 256-270页

作者： Bin zhou Yi DING Kang-Kang ZHANG guang-Ren DUAN Center for Control Theory and Guidance Technology Harbin Institute of Technology

In this paper, nonsingular prescribed-time control is studied based on periodic delayed sliding mode surfaces. Different from the existing sliding mode control, where either singularity problems may appear or the convergence time depends on the initial state, the proposed sliding mode control approaches can achieve prescribed-time convergence without singularity. The proposed nonsingular sliding mode control approaches can be applied to both second-order and high-order nonlinear systems with prescribed-time convergence. As applications of the proposed sliding mode control approaches, the control of hypersonic vehicle systems is revisited. Numerical simulations on the nonlinear model of the hypersonic vehicle system show the effectiveness of the proposed methods.

关键词： prescribed-time control smooth periodic delayed feedback sliding mode control high-order nonlinear systems hypersonic vehicle systems