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基于曲网格有限差分法的2.5D地震波数值模拟及逆时偏移成像

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基于曲网格有限差分法的2.5D地震波数值模拟及逆时偏移成像

作者： WANG Long 长安大学

学位级别：硕士

地震波数值模拟是研究地震波传播规律的重要方法,也是获得地层成像前的正演步骤。目前,地震波数值模拟方法经过不断地创新与完善,逐渐由解决2D数值模拟问题转向了3D问题。但在实际应用中,2D波场数值模拟由于存在线源假设造成的振幅畸变... 详细信息

地震波数值模拟是研究地震波传播规律的重要方法,也是获得地层成像前的正演步骤。目前,地震波数值模拟方法经过不断地创新与完善,逐渐由解决2D数值模拟问题转向了3D问题。但在实际应用中,2D波场数值模拟由于存在线源假设造成的振幅畸变和相移问题,导致计算精度难以满足实际需求,而3D波场数值模拟需要超大的计算量与计算机存储空间,很难应用于大尺度区域的勘探。因此,为了解决2D数值模拟计算精度不够而3D数值模拟又难以广泛应用的问题,人们提出了2.5D波场数值模拟方法。其原理是以假设地质模型沿走向方向物理性质不变为前提,通过沿走向方向做傅里叶变换将3D问题转换成重复的2D问题,在降低一定计算量的同时又保留了3D波场数值模拟的震源特征,满足精度需求。2.5D地震波数值模拟和逆时偏移成像的理论前提为假设模型在走向方向上物性一致,因此可以沿走向方向做傅里叶变换,推导出2.5D一阶速度-应力波动方程表达式,并使用有限差分法来离散波动方程。有限差分法中使用的常规矩形网格由于存在阶梯近似导致在含有起伏界面的复杂模型中会发生虚假散射,无法满足精度需求,因此我们使用曲网格有限差分法,根据直曲坐标转换原理将不规则的物理空间转换到规则的计算空间,推导出2.5D一阶速度-应力方程在曲坐标系下的表达式,并使用一种改进的DRP/opt Mac Comark差分格式在空间上进行离散,同时使用四阶Runge-Kutta法在时间上进行积分,提高数值模拟精度。使用2.5D地震波数值模拟方法分别沿时间正向和时间反方向进行波场外推得到震源波场和检波器波场,并使用互相关成像条件进行2.5D逆时偏移成像。常规的偏移方法是基于单程波的深度域偏移,由于近年来技术的发展,这种偏移方法已经不能满足当前的勘探需求。因此,我们选择使用基于双程波动方程在时间域进行波场外推的逆时偏移方法,这种方法同时包含地震波动力学和运动学特征,能够充分利用波场信息,具有不受地层倾角限制和对多种波进行偏移成像的显著优点。逆时偏移成像的三个主要过程为波场正演、逆时外推、去噪成像。

关键词：曲线网格有限差分法逆时偏移成像互相关成像条件 Poynting矢量

Prevalence and Associated Factors of Suicidal Behaviors Among Community-Dwelling Individuals with Serious Mental Disorders—Shandong Province,China,2022

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China CDC weekly 2023年第25期5卷 547-553,I0001,I0002页

作者： Meiqi wang long Sun Centre for Health Management and Policy Research School of Public HealthCheeloo College of MedicineShandong UniversityJinan CityShandong ProvinceChina NHC Key Lab of Health Economics and Policy Research Shandong UniversityJinan CityShandong ProvinceChina

Summary What is already known about this topic?Serious mental disorders(SMD)are significant risk factors for suicide,and individuals with SMD are crucial target populations for suicide prevention efforts.While numerous studies have examined the prevalence of suicidal behaviors among psychiatric inpatients,fewer reports have addressed the occurrence of such behaviors in community-based patients.What is added by this report?The prevalence of suicidal ideation,planning,and attempts among community-dwelling individuals with SMD was found to be 36.8%,17.9%,and 15.0%,respectively.A significant association was observed between the severity of psychiatric symptoms and the presence of suicidal behaviors.Notably,patients within the 55–59 age range demonstrated the highest rates of both suicidal planning and attempts.What are the implications for public health practice?Particular attention to the risk of suicide is crucial,especially for community-dwelling individuals with SMD of middle age,those with religious beliefs,living alone,and exhibiting more severe depressive and psychiatric symptoms.

关键词： religious prevention alone

Experimental Investigation on Liner Cooling Characteristics of a Mixed-Flow Trapped Vortex Combustor

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Journal of Thermal Science 2023年第6期32卷 2222-2234页

作者： ZHANG Jingyu wang Min WANG Long wang Jiaxi JIANG Ping HE Xiaomin College of Energy and Power Engineering Nanjing University of Aeronautics and AstronauticsNanjing210016China

The mixed-flow trapped vortex combustor(TVC)is a new type of combustor that applies trapped vortex flame stabilization technology to mixed-flow combustor.Compared with the traditional mixed-flow combustor,the mixed-flow TVC has many advantages,such as complicated structure of the vortex flow field inside liner,large cooling area,significant local hot spots on the liner,and large wall temperature gradient.In this paper,for a mixed-flow TVC with inclined multi-hole cooling,the liner wall temperature of an annular test rig was examined in experiments.The effects of inlet temperature(T3),inlet Mach number(Ma)and fuel to air ratio(FAR)on the temperature of liner wall were obtained,which provided a valuable reference for understanding the distribution characteristics of liner wall temperature.The experiment results show that the highest temperature is found to be on the fore-wall of the cavity.When T3 and FAR are low,the highest wall temperature was obtained in injector plane.However,the wall temperature in the center plane between two adjacent injectors was higher than that in injector plane under the condition of high FAR and T3.With the increase of FAR and T3,the average wall temperature increases.Ma has a slight impact on the average wall temperature.In addition,this paper provides an effective reference for the design and improvement of the liner cooling structure of the combustor with many discontinuous small-area walls in the flow direction.It is difficult to form a continuous film,and cooling requirements can’t be achieved only by using inclined multi-hole cooling structure.Consideration needs to be given to other efficient cooling structures,or to the combination of multiple cooling structures.

关键词： mixed-flow TVC liner cooling inclined multi-hole cooling wall temperature experiment

New hybrid inertial CQ projection algorithms with line-search process for the split feasibility problem

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Applied Mathematics(A Journal of Chinese Universities) 2023年第1期38卷 144-158页

作者： DANG Ya-zheng WANG Long YANG Yao-heng School of Management University of Shanghai for Science and TechnologyShanghai 200093China

In this paper, we propose two hybrid inertial CQ projection algorithms with linesearch process for the split feasibility problem. Based on the hybrid CQ projection algorithm, we firstly add the inertial term into the iteration to accelerate the convergence of the algorithm, and adopt flexible rules for selecting the stepsize and the shrinking projection region, which makes an optimal stepsize available at each iteration. The shrinking projection region is the intersection of three sets, which are the set C and two hyperplanes. Furthermore, we modify the Armijo-type line-search step in the presented algorithm to get a new algorithm.The algorithms are shown to be convergent under certain mild assumptions. Besides, numerical examples are given to show that the proposed algorithms have better performance than the general CQ algorithm.

关键词： split feasible problem inertial Armijo-type line-search technique projection algorithm convergence

Cooperative Target Tracking of Multiple Autonomous Surface Vehicles Under Switching Interaction Topologies

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IEEE/CAA Journal of Automatica Sinica 2023年第3期10卷 673-684页

作者： Lang Ma Yu-long wang Qing-long Han Shanghai Key Laboratory of Power Station Automation Technology and the School of Mechatronic Engineering and AutomationShanghai UniversityShanghai 200444China School of Science Computing and Engineering TechnologiesSwinburne University of TechnologyMelbourne VIC 3122Australia IEEE

This paper is concerned with the cooperative target tracking of multiple autonomous surface vehicles(ASVs)under switching interaction topologies.For the target to be tracked,only its position can be measured/received by some of the ASVs,and its velocity is unavailable to all the ASVs.A distributed extended state observer taking into consideration switching topologies is designed to integrally estimate unknown target dynamics and neighboring ASVs'dynamics.Accordingly,a novel kinematic controller is designed,which takes full advantage of known information and avoids the approximation of some virtual control vectors.Moreover,a disturbance observer is presented to estimate unknown time-varying environmental disturbance.Furthermore,a distributed dynamic controller is designed to regulate the involved ASVs to cooperatively track the target.It enables each ASV to adjust its forces and moments according to the received information from its neighbors.The effectiveness of the derived results is demonstrated through cooperative target tracking performance analysis for a tracking system composed of five interacting ASVs.

关键词： Autonomous surface vehicles(ASVs) cooperative target tracking distributed extended state observer switching topologies

New Identification of Quaternary Uranium Mineralization at the Mianhuakeng Granite-Related Uranium Deposit,South China

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地球科学学刊:英文版 2023年第5期34卷 1635-1640页

作者： long Zhang Fangyue wang Ore Deposit and Exploration Centre School of Resources and Environmental EngineeringHefei University of TechnologyHefei 230009China Anhui Province Engineering Research Center for Mineral Resources and Mine Environments Hefei 230009China

0 INTRODUCTION Granite-related uranium deposits are one of the most important types of uranium deposits in South China,and their genetic model generally involves uranium leaching from the preexisting rocks(mainly granites),U transport as uranyl carbonate and fluoride complexes and probably chloride complexes in hydrothermal solutions,and U precipitation caused by physicochemical changes(Chi et al.,2020;Hu et al.,2008).Mineralization ages of granite-related uranium deposits in South China have been a subject of significant controversy among researchers and were investigated using several methods,such as bulk uraninite U-Pb isotopic dating,in situ analytical techniques,pyrite Rb-Sr dating as well as bulk uraninite Sm-Nd dating(e.g.,Zhang et al.,2022;Zhong et al.,2019;Bonnetti et al.,2018;Luo et al.,2015;Huang et al.,2010;Ye,2005).

关键词： dating uranium Bonnet

A Versatile,Electrophilic Reagent for Monofluoromethylthiolation

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Chinese Journal of Chemistry 2023年第18期41卷 2317-2329页

作者： Rui wang long Lu Qilong Shen Key Laboratory of Organofluorine Chemistry Shanghai Institute of Organic ChemistryUniversity of Chinese Academy of SciencesChineseAcademyof Sciences345 Lingling RoadShanghai 200032China

Comprehensive Summary,A new electrophilic monofluoromethylthiolating reagent N-fluoromethylthiophthalimide PhthSCH2F 1 was developed.Reagent 1 could be readily synthesized from easily available starting materials benzyl mercaptan and CH_(2)FCl in three steps.N-Fluoromethylthiophthalimide 1 is a powerful electrophilic monofluoromethylthiolating reagent that allows the monofluoromethylthiolation of a wide range of nucleophiles including alkynes,aryl/vinyl boronic acids,electron-rich heteroarenes,β-ketoesters and oxindoles,as well as thiols under mild conditions.

关键词： Fluorine Monofluoromethylthiolation Electrophilic Sulfur

Coding function for non-coding RNA in plants—insights from miRNA encoded peptide(miPEP)

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Science China(Life Sciences) 2015年第5期58卷 503-505页

作者： WANG Long wang Jia-Wei National Key Laboratory of Plant Molecular Genetics Institute of Plant Physiology and Ecology Shanghai Institutes for Biological Sciences Shanghai Tech University

Non-coding RNAs(nc RNAs)refer to a large and diverse collection of polyadenylated or non-polyadenylated RNA transcripts with low protein coding potential.In general,the house-keeping nc RNAs(e.g.,ribosomal RNAs and tr... 详细信息

关键词：非编码RNA miRNA 植物核糖体RNA RNA聚合酶 RNA加工转录物微RNA

When Electronically Inert Polymers Meet Conjugated Polymers:Emerging Opportunities in Organic Photovoltaics

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Chinese Journal of Polymer Science 2022年第8期40卷 861-869,I0006页

作者： Jing-Jing wang long Ye School of Materials Science&Engineering Tianjin Key Laboratory of Molecular Optoelectronic SciencesTianjin UniversityCollaborative Innovation Center of Chemical Science and Engineering(Tianjin)Tianjin300350China State Key Laboratory of Applied Optics Changchun Institute of OpticsFine Mechanics and PhysicsChinese Academy of SciencesChangchun130033China

Insulating polymers(commodity plastics in particular)are a major category of polymeric materials widely used in our daily life,but they exhibit abysmal electrical conductivity.Instead,conjugated polymers are gaining tremendous interest due to their excellent electrical properties and versatile applications in organic electronics.In this perspective,we provide a concise account of the added value in organic solar cells,as brought by the combined use of conjugated and insulating polymers.The challenging tasks and prospective directions are given to the potential benefits of employing insulating polymer additives,which spans from common commodity plastics to high-temperature resistant resins and thermoplastic elastomers.Particularly,the inert polymers can improve many important properties such as mechanical and thermal robustness but not sacrifice optoelectronic performance.

关键词： Organic solar cells Insulating polymers Photovoltaic polymers Miscibility Morphology