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Debris Flow Susceptibility Evaluation in Meizoseismal Region:A Case Study in Jiuzhaigou,China

Journal of Earth Science 2024年第1期35卷 263-279页

作者： Yongwei Li Linrong xu Yonghui shang Shuyang Chen School of Civil Engineering Central South UniversityChangsha 410075China National Engineering Research Center of High-Speed Railway Construction Technology Central South UniversityChangsha 410075China School of Civil Engineering Central South University of Forestry and TechnologyChangsha 410004China

Jiuzhaigou is situated on a mountain-canyon region and is famous for frequent tectonic *** abundance of loose co-seismic landslides and collapses were produced on gullies after the Jiuzhaigou Earthquake on August 8,2017,which was served as material source for debris flow in later *** flow appears frequently which are seriously endangering the safety of people's lives and *** the earliest debris flow appeared in areas where no case ever reported *** debris flow susceptibility evaluation(DFSE)is used for predicting the areas prone to debris flow,which is urgently required to avoid hazards and help to guide the strategy of preventive ***,this work employs debris flow in Jiuzhaigou to reveal the characteristics of disaster-pregnant environment and to explore the application of machine learning in *** new viewpoints are suggested:(i)Material density factor of debris flow is first adopted in this work,and it is proved to be a critical factor for triggering debris flows by sensitivity analysis method.(ii)Deep neural network and convolutional neural network(CNN)achieve relatively good area under the curve(AUC)values and are 0.021-0.024 higher than traditional machine learning methods.(iii)Watershed units combined with CNNbased model can achieve more accurate,reliable and practical susceptibility *** work provides an idea for prevention of debris flow in mountainous lands.

关键词： machine learning earthquakes debris flow susceptibility convolutional neural network deep neural network watershed unit

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Single-cell spatial transcriptomics in cardiovascular development,disease,and medicine

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Genes & Diseases 2024年第6期11卷 192-204页

作者： Songjie han Qianqian xu Yawen Du Chuwei Tang Herong Cui Xiaofeng Xia Rui Zheng Yang Sun Hongcai shang Key Laboratory of Chinese Internal Medicine of Ministry of Education Dongzhimen HospitalBeijing University of Chinese MedicineBeijing 100700China School of Life Sciences Beiing University of Chinese MedicineBeijing 102488China

Cardiovascular diseases(CVDs)impose a significant burden *** the elucidation of the etiology and underlying molecular mechanisms of cvDs by numerous studies and recent discovery of effective drugs,their morbidity,disability,and mortality are still ***,precise risk stratification and effective targeted therapies for CvDs are *** improvements in single-cell RNA sequencing and spatial transcriptomics have improved our understanding of the mechanisms and cells involved in cardiovascular phylogeny and ***-cell RNA sequencing can facilitate the study of the human heart at remarkably high res-olution and cellular and molecular ***,this technique does not provide spatial information,which is essential for understanding homeostasis and *** tran-scriptomics can elucidate intracellular interactions,transcription factor distribution,cell spatial localization,and molecular profiles of mRNA and identify cell populations causing the disease and their underlying mechanisms,including cell ***,we introduce the main methods of RNA-seq and spatial transcriptomics analysis and highlight the latest ad-vances in cardiovascular *** conclude that single-cell RNA sequencing interprets dis-ease progression in multiple dimensions,levels,perspectives,and dynamics by combining spatial and temporal characterization of the clinical phenome with multidisciplinary tech-niques such as spatial *** aligns with the dynamic evolution of CVDs(e.g.,"angina-myocardial infarction-heart failure"in coronary artery disease).The study of pathways for disease onset and mechanisms(e.g.,age,sex,comorbidities)in different patient subgroups should improve disease diagnosis and risk *** can facilitate precise individualized treatment of CVDs.

关键词： Cardiovascular disease Precision medicine Single-cellspatial transcriptomics Single-cell transcriptome Spatial transcriptome Transcriptomics

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Variable structure guidance law for attacking surface maneuver targets

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Journal of Systems Engineering and Electronics 2008年第2期19卷 337-341页

作者： han Yanhua xu Bo Coll. of Astronautics Nanjing Univ. of Aeronautics and Astronautics Nanjing 210016 P. R. China

The characteristics of surface maneuver targets are analyzed and a 3-D relative motion model for missiles and targets is established. A variable structure guidance law is designed considering the characteristics of targets. In the guidance law, the distance between missiles and targets as well as the missile-target relative velocity are all substituted by estimation values. The estimation errors, the target＇s velocity, and the maneuver acceleration are all treated as bounded disturbance. The guidance law proposed can be implemented conveniently in engineering with little target information. The performance of the guidance system is analyzed theoretically and the numerical simulation result shows the effectiveness of the guidance law.

关键词： air-to-surface missile guidance law variable structure control surface maneuver target.

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Molecular network-based intervention brings us closer to ending the HIV pandemic

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Frontiers of Medicine 2020年第2期14卷 136-148页

作者： Xiaoxu han Bin Zhao Minghui An Ping Zhong Hong shang Key Laboratory of AIDS Immunology of National Health Commission Department of Laboratory MedicineThe First Affiliated HospitalChina Medical UniversityShenyang 110001China Key Laboratory of AIDS Immunology Chinese Academy of Medical SciencesShenyang 110001China Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases Hangzhou 310003China Department of AIDS and STD Shanghai Municipal Center for Disease Control and PreventionShanghai 200336China

Precise identification of HIV transmission among populations is a key step in public health ***,the HIV transmission network is usually difficult to *** molecular networks can be determined by phylogenetic approach,genetic distance-based approach,and a combination of both *** approaches are increasingly used to identify transmission networks among populations,reconstruct the history of HIV spread,monitor the dynamics of HIV transmission,guide targeted intervention on key subpopulations,and assess the effects of *** and retrospective studies have demonstrated that these molecular network-based interventions are more cost-effective than random or traditional ***,we still need to address several challenges to improve the practice of molecular network-guided targeting interventions to finally end the HIV *** data remain limited or difficult to obtain,and more automatic real-time tools are *** addition,molecular and social networks must be combined,and technical parameters and ethnic issues warrant further studies.

关键词： human immunodeficiency virus type 1 molecular cluster transmission cluster risk network targeted intervention evaluation

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Drop impact dynamic and directional transport on dragonfly wing surface

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Friction 2023年第5期11卷 737-747页

作者： Jing xu Wenjun LIU Weixiao shang Jun CHEN Jiadi LIAN School of Mechanical Engineering Hangzhou Dianzi UniversityHangzhou 310018China School of Mechanical Engineering Purdue UniversityWest LafayetteIndiana 47907USA College of Mechanical and Electrical Engineering China Jiliang UniversityHangzhou 310018China

The ability of dragonflies to fly in the rain without being wetted by raindrops has motivated researchers to investigate the impact behavior of a drop on the superhydrophobic wings of *** superhydrophobic surface is used as a reference for the design of directional surfaces and has attracted extensive attention owing to its wide applicability in microfluidics,self-cleaning,and other *** this study,the static contact angle and rebound process of a drop impacting a dragonfly wing surface are investigated experimentally,whereas the wetting pressure,Gibbs free energy,and Stokes number *** of restitution are theoretically calculated to examine the dynamic and unidirectional transport behaviors of the *** show that the initial inclination angle of the dragonfly wing is similar to the sliding angles along with the drop *** water drop bounces from the bottom of the dragonfly wing to the distal position,demonstrating directional *** drop impacts the dragonfly wing surface,and the drop exhibits compression,recovery,and separation phases;in these three phases,the drop morphology *** the Gibbs free energy and cross-sectional area evolve,the coefficient of restitution decreases as the drop continues to bounce,and the Stokes number increases.

关键词： dragonfly wing superhydrophobic wettability directional transport bounce

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Wormhole Solution in Lovelock Gravity Theory

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Chinese Physics Letters 1999年第2期16卷 85-87页

作者： shang Yan-wen xu Jian-jun Department of Physics Fudan UniversityShanghai 200433

In this work,we confirm the existence of wormhole solution in general form of Lovelock gravity theory,and present some diagrams from the numerical calculation with special coupling constants as support to our ***,we also find out that whether the cosmology constant is actually zero is also critical to the behavior of the solution as it is in general relativity.

关键词： conclusion constants coupling

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Meta-analysis of risk factors for Parkinson’s disease dementia

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Translational Neurodegeneration 2016年第1期5卷 87-94页

作者： Yaqian xu Jing Yang Huifang shang Department of Neurology West China HospitalSichuan University610041 ChengduSichuanChina

Background:Parkinson’s disease(PD)is a common heterogeneous neurodegenerative disorder in elder ***’s disease dementia(PDD)is one of the most common non-motor manifestations in PD *** comprehensive review has been conducted to assess risk factors for ***:A systemic search for studies on PDD risk factors was *** and case–control studies that clearly defined PDD and presented relevant data were *** data were analyzed to generate a pooled effect size and 95%confidence interval(CI).Publication bias was assessed using the Egger’s test and the Begg’s ***:A systematic search was conducted and yielded 5195 *** screening,25 studies were included in the current *** of PDD was positively associated with age(odds ratio[OR]1.07,95% CI 1.03-1.13),male(OR 1.33,95% CI 1.08-1.64),higher Unified Parkinson’s Disease Rating Scale(UPDRS)part III scores(relative risk[RR]1.04,95% CI 1.01-1.07),hallucination(OR 2.47,95% CI 1.36-4.47),REM sleep behavior disorder(RBD)(OR 8.38,95% CI 3.87-18.08),smoking(ever ***)(RR 1.93,95% CI 1.15-3.26)and hypertension(OR 1.57,95% CI 1.11-2.22).An inverse association was found between education(RR 0.94,95% CI 0.91-0.98)and *** reported factors,including age of onset,disease duration of PD,Hoehn and Yahr stage and diabetes mellitus were not significantly associated with ***:Advanced age,male,higher UPDRS III scores,hallucination,RBD,smoking and hypertension increase the risk of PDD,whereas higher education is a protective factor for PDD.

关键词： Parkinson’s disease Dementia Risk factors Predictors

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Simplification method of thermal-fluid network with circulation reflux based on matrix operation

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Science China(Technological Sciences) 2020年第7期63卷 1202-1211页

作者： han RuBing xu XiangHua LIANG XinGang Key Laboratory for Thermal Science and Power Engineering of Ministry of Education Department of Engineering MechanicsTsinghua UniversityBeijing 100084China

Modeling and simulation of thermal-fluid systems are very important in industrial numerical simulation and play key roles in their design and control. In this paper, the modeling and simplification method of one-dimensional thermal-fluid network with variable-property are presented, including matrix representation of the network, simplification algorithm for series/parallel connection based on matrix operation and generation of flow equations based on system topology. This simplification is suitable for the simulation of thermal-fluid systems with arbitrary topological structure. The method to treat reflux during iteration is proposed. The outstanding features of the simplification algorithm are the significant reduction in the thermal-fluid network and therefore the number of the related governing equations, as well as the computation burden. The example in this paper shows that the number of the governing equations for flow is reduced by about 45% and the calculation time of flow calculation is reduced by an average of 32% after the simplification.

关键词： thermal-fluid system network simplification incidence matrix multiple pumps and multiple circulation refluxes

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A UNIFIED MULTIAXIAL FATIGUE DAMAGE PARAMETER

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Acta Mechanica Solida Sinica 1998年第3期11卷 261-274页

作者： shang Deguang Wang Dejun xu Hao Nanjing Univ Aeronaut & Astronaut Dept Aircraft Engn Nanjing 210016 Peoples R China

According to the critical plane principle, a unified multiaxialfatigue damage parameter is presented based on the varying behaviourof the strains on the critical plane. Both the parameters of themaximum shear strain amplitude and normal strain excursion betweenadjacent turning points of the maximum shear strain on the criticalplane are considered in the multiaxial fatigue damage parme- terpresented. An equivalent strain amplitude is made with bothparameters of the maximun shear strain amplitude and normal strainexcursion by means of von Mises criterion. Thus a new multiaxialfatigue damage model is given based on the critical plane approach.

关键词： multiaxial fatigue critical plane approach proportional loading

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Studying the Effect of the Pre-Stimulation Paradigm on Steady-State Visual Evoked Potentials with Dynamic Models Based on the Zero-Pole Analytical Method

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Tsinghua Science and Technology 2020年第3期25卷 435-446页

作者： shangen Zhang xu han Xiaorong Gao the Department of Biomedical Engineering School of Medicine Tsinghua University

This study explored methods for improving the performance of Steady-State Visual Evoked Potential(SSVEP)-based Brain-Computer Interfaces(BCI), and introduced a new analytical method to quantitatively analyze and reflect the characteristics of SSVEP. We focused on the effect of the pre-stimulation paradigm on the SSVEP dynamic models and the dynamic response process of SSVEP, and performed a comparative analysis of three pre-stimulus paradigms(black, gray, and white). Four dynamic models with different orders(second-and third-order)and with and without a zero point were used to fit the SSVEP envelope. The zero-pole analytical method was adopted to conduct quantitative analysis on the dynamic models, and the response characteristics of SSVEP were represented by zero-pole distribution characteristics. The results of this study indicated that the pre-stimulation paradigm affects the characteristics of SSVEP, and the dynamic models had good fitting abilities with SSVEPs under various types of pre-stimulation. Furthermore, the zero-pole characteristics of the models effectively characterize the damping coefficient, oscillation period, and other SSVEP characteristics. The comparison of zeros and poles indicated that the gray pre-stimulation condition corresponds to a lower damping coefficient, thus showing its potential to improve the performance of SSVEP-BCIs.

关键词： Steady-State Visual Evoked Potential(SSVEP) dynamic model pre-stimulation zero and pole analysis brain-computer interface

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