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邻近堆载作用下桥梁桩基内力与变形数值分析

粉煤灰综合利用 2024年第5期38卷 59-64页

作者：马迪陕西师范大学国有资产管理处陕西西安710119

采用数值分析方法,研究堆载对邻近桥梁桩基内力与变形的影响。使用耦合欧拉-拉格朗日法建立了堆载作用下某特大桥654#桥墩桩基三维有限元模型,以桥墩轨道顶面横向位移实测值与计算值对比验证了模型的有效性。据此模型计算结果分析了邻... 详细信息

采用数值分析方法,研究堆载对邻近桥梁桩基内力与变形的影响。使用耦合欧拉-拉格朗日法建立了堆载作用下某特大桥654#桥墩桩基三维有限元模型,以桥墩轨道顶面横向位移实测值与计算值对比验证了模型的有效性。据此模型计算结果分析了邻近大量堆土情况下桩基的内力和变形特性:各桩水平位移都在1/2L附近的淤泥质粉质黏土层达到最大值;各桩1/6L~2/3L范围内桩身产生附加弯矩的最大值为210 kN·m;且在距堆载较近的桩基上部引起了负摩擦力,进而产生了581~1368 kN的附加轴力。结果表明堆载严重劣化了桩基的工作性能。可为主动防控堆载引发的墩台偏移等病害研究提供一种可行的方法。

关键词：堆载桥梁桩基 CEL 数值分析内力变形

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堆载作用下邻近单桩响应的耦合与非耦合分析

粉煤灰综合利用 2023年第3期37卷 42-49页

作者：马迪陕西师范大学国有资产管理处陕西西安710119

本文介绍了两种计算堆载对邻近单桩影响的方法:目前较常用的是将土和桩的响应分开求解的非耦合方法;另一种为使用显式耦合欧拉-拉格朗日(CEL)技术建立数值分析模型。计算并比较了耦合/非耦合方法所得的桩基响应,并分析其结果差异的原因... 详细信息

本文介绍了两种计算堆载对邻近单桩影响的方法:目前较常用的是将土和桩的响应分开求解的非耦合方法;另一种为使用显式耦合欧拉-拉格朗日(CEL)技术建立数值分析模型。计算并比较了耦合/非耦合方法所得的桩基响应,并分析其结果差异的原因。此外,应用CEL耦合模型对堆载间距、强度、桩径进行参数敏感性分析得出:(1)堆载距离单桩越近,0~5 m深度内桩的水平位移越大,桩顶位置尤其突出。间距为1.0 B时弯矩最大值相对于间距0.5 B减小约71%、间距为1.5 B时弯矩最大值相对于间距B减小约57.3%;(2)堆载强度增加,桩身水平位移增加。堆载下沉深度为0.05 B时桩基弯矩最大值与下沉0.1 B基本一致,只是弯矩最大值点深度增加;堆载下沉深度为0.15 B时桩基弯矩最大值相对于下沉0.1 B增加约88.3%;(3)桩径由0.375 m增大到0.75 m可使桩顶位移减小82%,桩基相对弯矩(M/EI)最大值减小73%。

关键词：堆载耦合法非耦合法耦合欧拉-拉格朗日法 CEL 数值分析土体变形

基于综合压力指数的贫困地区金融风险测度研究——以陕西省商洛市为例

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西部金融 2019年第4期 72-77页

作者：马迪中国人民银行商洛市中心支行

本文以贫困地区金融风险为研究对象,选取区域经济指标、金融机构风险指标、房地产市场指标、制度环境等基础指标,采用主成分分析方法构建了金融综合压力指数,并使用误差修正模型(VEC)和脉冲响应函数对GDP增长对金融综合压力指数的冲击... 详细信息

本文以贫困地区金融风险为研究对象,选取区域经济指标、金融机构风险指标、房地产市场指标、制度环境等基础指标,采用主成分分析方法构建了金融综合压力指数,并使用误差修正模型(VEC)和脉冲响应函数对GDP增长对金融综合压力指数的冲击路径进行了有效性检验。该指数表明了金融压力状况主要受到经济增长动力、经济增长稳健性和社会脆弱性影响,贫困地区金融风险与经济增速回落、地方债务风险、贫困人口占比较大等因素密切相关。实证研究表明,GDP增长率对金融风险有一定的预测作用,能够作为金融风险预测的先行指标。

关键词：金融风险压力指数贫困地区

Cortical spreading depression-induced preconditioning in the brain

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Neural Regeneration Research 2016年第11期11卷 1857-1864页

作者： Ping-ping Shen Shuai Hou di ma Ming-ming Zhao Ming-qin Zhu Jing-dian Zhang Liang-shu Feng Li Cui Jia-chun Feng Institute of Neuroscience Center and Neurology Department the First Affiliated Hospital of Jilin University

Cortical spreading depression is a technique used to depolarize neurons. During focal or global ischemia, cortical spreading depression-induced preconditioning can enhance tolerance of further injury. However, the underlying mechanism for this phenomenon remains relatively unclear. To date, numerous issues exist regarding the experimental model used to precondition the brain with cortical spreading depression, such as the administration route, concentration of potassium chloride, induction time, duration of the protection provided by the treatment, the regional distribution of the protective effect, and the types of neurons responsible for the greater tolerance. In this review, we focus on the mechanisms underlying cor- tical spreading depression-induced tolerance in the brain, considering excitatory neurotransmission and metabolism, nitric oxide, genomic reprogramming, inflammation, neurotropic factors, and cellular stress response. Specifically, we clarify the procedures and detailed information regarding cortical spreading depression-induced preconditioning and build a foundation for more comprehensive investigations in the field of neural regeneration and clinical application in the future.

关键词： nerve regeneration cortical spreading depression neuronal depolarization ischemic tolerance peri-infarct depolarization excitatory neurotransmission nitric oxide genomic reprogramming inflammation neurotropic factors cellular stress response neural regeneration

Network pharmacology and molecular docking techniques to explore the mechanism of Smilax china *** the treatment of myocardial infarction

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Precision Medicine Research 2023年第1期5卷 15-24页

作者： Qing Lan Peng-Yu Wang Shuo Zhang Qiao-Yun Zhang Tong Wang Guan-di ma You-Zhi Zhang School of Pharmacy Xianning Medical CollegeHubei University of Science and TechnologyXianning 437100China

Objective:To predict the relevant targets and signaling pathways of Smilax china L.(SC)for treating myocardial infarction on the basis of network pharmacology and molecular ***,the basis for additional in-depth investigation is ***:First,the targets of SC and the targets for treating myocardial infarction were screened from different databases,Then the intersection genes of SC for treating myocardial infarction were performed in Venny ***,to obtain the protein interaction network,the Metascape database,String database,were used to analyze the important modules related to the signaling pathway using MCODE ***,the DAVID database was used for Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment *** we constructed the“interaction targets-pathways”network by Cytoscape software,and using Network Analyzer was used to screen the core compound,core targets and core ***,molecular docking was used to verify whether the core compounds and core targets had better docking ***:11 active ingredients and 98 targets of SC,1846 targets to treat myocardial infarction and 58 targets related to treat myocardial infarction in SC were obtained;MCODE analysis of the protein-protein interaction network yielded 4 important modules related to signaling pathways;Gene Ontology enrichment analysis yielded 848 entries and Kyoto Encyclopedia of Genes and Genomes enrichment analysis yielded 144 signaling pathways;the core compounds were beta-sitosterol,diosgenin,kaempferol,core targets were AKT1,CASP9,BCL2,core pathways were pathways in cancer,pathways of neurodegeneration-multiple diseases,Kaposi’s sarcoma-associated herpesvirus infection,lipid and atherosclerosis and human cytomegalovirus ***,molecular docking between core components and core targets was ***:The preliminary prediction of the mechanism of the SC in the treatment of myocardial infarction is that it

关键词： Smilax china L. myocardial infarction network pharmacology molecular docking

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图书美誉度及对高校图书馆工作的影响

图书馆论坛 2012年第1期32卷 152-155页

作者：马迪倩孔令国南开大学图书馆天津300071

图书美誉度是通过读者对图书的综合评价来赋予图书不同的美誉程度。作为新的馆藏宣传渠道,图书美誉度能揭示藏书使用率、挖掘潜在价值;对流通、采访、优化馆藏等工作起到直接推动作用;在发挥高校教辅职能、塑造良好服务形象方面也会产... 详细信息

图书美誉度是通过读者对图书的综合评价来赋予图书不同的美誉程度。作为新的馆藏宣传渠道,图书美誉度能揭示藏书使用率、挖掘潜在价值;对流通、采访、优化馆藏等工作起到直接推动作用;在发挥高校教辅职能、塑造良好服务形象方面也会产生积极影响。

关键词：图书美誉度馆藏宣传藏书利用率

Seasonality regulates the effects of resource addition on plant diversity and ecosystem functioning in semi-arid grassland

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Journal of Plant Ecology 2021年第6期14卷 1143-1157页

作者： Feng-Wei Xu Jian-Jun Li Ji-Shuai Su Xiao-Ming Lu Yang Wang Li-Ji Wu Chao-Nan Wang di-ma Chen Yong-Fei Bai State Key Laboratory of Vegetation and Environmental Change Institute of BotanyChinese Academy of SciencesBeijing 100093China Research Institute of Forestry Chinese Academy of ForestryBeijing 100091China Grassland Research Center National Forestry and Grassland AdministrationBeijing 100091China Collaborative Innovation Center of Jiangxi Typical Trees Cultivation and Utilization College of ForestryJiangxi Agricultural UniversityNanchang 330045China College of Biological and Pharmaceutical Sciences China Three Gorges UniversityYichang 443002China College of Lifesciences University of Chinese Academy of SciencesBeijing 100049China College of Resources and Environment University of Chinese Academy of SciencesBeijing 100049China

Aims Seasonal variations in species richness,aboveground net primary productivity(ANPP)and stability under resource enrichment are frequently *** study explores how the impacts of resource enrichment on species richness,ANPP and stability vary among seasons in semi-arid *** We conducted a 3-year experiment in an Inner Mongolia grassland to determine the effects of resource input(water[W],nitrogen[N])on species richness,community ANPP and stability using seasonal sampling during the growing season(2013–2015).Structural equation modeling(SEM)was used to examine the relative importance of resource input on community stability via mechanistic pathways in each month and the whole growing *** Findings Resource inputs did not affect community ANPP in may and June,while N and/or NW enhanced ANPP in July and *** inputs generally did not affect species richness,asynchrony or community stability in most of the *** responses of perennial bunchgrasses(PB)to N and/or NW treatments contributed to the increased community ANPP in July and *** asynchrony may be the major mechanism contributing to community stability in may and June and the entire growing season,and PB stability is potentially the primary factor controlling community stability in July and August under resource *** results indicate that season and resource availability could interact to regulate species richness,community ANPP and stability in semi-arid *** findings have important implications for management practices in semi-arid grasslands in order to mitigate the impact of land use and global change.

关键词： season resource enrichment species richness aboveground net primary productivity(ANPP) community stability plant functional groups

Preliminary adipose removal did not prevent diet-induced metabolic disorders in mice

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Chinese Medical Journal 2021年第6期134卷 716-724页

作者： Lin Liu Chen-Xi Liang Xiao-Wei Wang Ke-Xin Pei Xin-di ma Chun-Xi Zhang Jing-Hui Dong Ming-Ming Gao Jia-Wei Liao Department of Biochemistry and Molecular Biology College of Basic MedicineHebei University of Chinese MedicineShijiazhuangHebei 050200China Laboratory of Lipid Metabolism Institute of Basic MedicineHebei Medical UniversityShijiazhuangHebei 050017China Department of Cardiology First Hospital of Hebei Medical UniversityShijiazhuangHebei 050031China Department of Physiology Hebei Medical UniversityShijiazhuangHebei 050017China Department of Cardiology Institute of Cardiovascular DiseasesFirst Affiliated Hospital of Dalian Medical UniversityDalianLiaoning 116011China

Background: Obesity is a fundamental factor in metabolic disorders such as hyperlipidemia, insulin resistance, fatty liver, and atherosclerosis. However, effective preventive measures are still lacking. This study aimed to investigate different surgical protocols for removing partial adipose tissue before the onset of obesity and determine whether, and by which protocol, preliminary adipose removal could exert potent preventive effects against diet-induced metabolic ***: male low-density lipoprotein receptor (LDL-R) knockout (KO) mice were randomly divided into four groups and subjected to epididymal fat removal (Epi-FR) surgery, subcutaneous fat removal (suQ-FR) surgery, both subcutaneous and epididymal fat removal (Epi + suQ-FR) surgery, or sham-operation. After 1 week of recovery, all mice were given a high-fat diet (HFD) for 10 weeks to induce metabolic ***: In the Epi-FR group and the sham-operated group, the mean numbers of the residual subcutaneous fat were 28.59 mg/g and 18.56 mg/g, respectively. The expression of relative genes such asPparg, Cebpa, Dgat2, Fabp4 and Cd36 in the residual subcutaneous fat increased 2.62, 3.90, 3.11, 2.06, 1.78 times in the Epi-FR group compared with that in the sham-operated group. Whereas in the other fat-removal groups, the residual fat depots had no significant change in either size or gene expression, as compared with those of the sham-operated group. Plasma lipid and glucose levels and insulin sensitivity, as detected by the glucose tolerance test, were not significantly alleviated in the three fat removal groups. Liver mass or lipid content was not attenuated in any of the three fat removal groups. The atherosclerosis burdens in the entire inner aorta and aortic root did not decrease in any of the three fat removal ***: Our data suggest that removal of epididymal adipose or subcutaneous adipose alone or in combination before the onset of obesity did not protect against hyperlipi

关键词： Adipose removal Hyperlipidemia Insulin resistance Fatty liver Atherosclerosis

重/轻单模界面的Richtmyer-Meshkov不稳定性研究

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中国科学：物理学、力学、天文学 2020年第10期50卷 48-56页

作者：马迪丁举春罗喜胜中国科学技术大学近代力学系合肥230026

本文采用实验与数值相结合的方法研究平面激波冲击重/轻单模界面的Richtmyer-Meshkov(RM)不稳定性问题,着重分析重/轻型界面和轻/重型界面演化的差异.实验上,利用先进的肥皂膜界面生成方法,生成初始形状可控的SF6/air单模界面,并基于高... 详细信息

本文采用实验与数值相结合的方法研究平面激波冲击重/轻单模界面的Richtmyer-Meshkov(RM)不稳定性问题,着重分析重/轻型界面和轻/重型界面演化的差异.实验上,利用先进的肥皂膜界面生成方法,生成初始形状可控的SF6/air单模界面,并基于高速纹影技术捕捉界面和波系的详细演化过程.数值上,采用可压缩多组分流动高精度数值模拟程序对实验工况进行模拟,数值模拟结果和实验结果吻合良好,详细的数值流场信息促进了我们对实验中界面分层现象的分析和理解.研究发现,与轻/重界面演化不同的是,重/轻界面在激波冲击后首先进入反相阶段;与轻/重界面演化类似的是,反相后的重/轻界面依次经历线性和非线性发展.最后,本文利用实验获得的定量数据检验已有线性和非线性模型对重/轻RM不稳定性的预测能力,发现Meyer&Blewett模型(***,1972,15:753–759)能有效预测重/轻界面的线性期扰动增长,而dimonte&Ramaprabhu模型(***,2010,22:014104)能有效预测非线性期的扰动增长.

关键词： Richtmyer-Meshkov不稳定性反相界面分层