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WALL PRESSURE FLUCTUATIONS OF TURBULENT FLOW OVER BACKWARD-FACING STEP WITH AND WITHOUT ENTRAINMENT: MICROPHONE ARRAY MEASUREMENT

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Journal of Hydrodynamics 2006年第4期18卷 393-396页

作者： ke feng LIU ying-zheng WANG Wei-zhe CHEN Han-ping School of Mechanical and Power Engineering Shanghai Jiaotong University Shanghai 200030 China

Wall pressure fluctuations in turbulent boundary layer flow over backward-facing step with and without entrainment were investigated. Digital array pressure sensors and multi-arrayed microphones were employed to acquire the time-averaged static pressure and fluctuating pressure, respectively. The differences of two flows were scrutinized in terms of static pressure characteristics, pressure fluctuations, cross-correlation and coherence of wall pressure. Introduction of the entrainment increased scale of large-scale vortical structure and reduced its convection velocity. However, shedding frequency of large-scale vortical structures was found to be the same for both flows.

关键词： backward-facing step turbulent boundary layer entrainment wall pressure fluctuations Microphone Array

SIMULTANEOUS FLOW VISUALIZATION AND WALL-PRESSURE MEASUR EMENT OF THE TURBULENT SEPARATED AND REATTACHING FLOW OVER A BACKWARD-FACING STEP

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Journal of Hydrodynamics 2007年第2期19卷 180-187页

作者： ke feng LIU ying-zheng CHEN Han-ping HIDE S.Koyama School of MechaniCal andPower Engineering Shanghai Jiaotong University Shanghai 200030 China Department of Mechanical Engineering Tokyo Denki University Tokyo Japan

Unsteady behaviors of the large-scale vortical structure superimposed in the turbulent separated and reattaching flow over a backward-facing step were convincingly delineated by performing simultaneous measurements of the wall pressure fluctuations and visualizations of the flow. Toward this end, a synchronized instrumentation system integrated with the microphone array and the high-speed camera was established. The smoke-wire technique was employed to visualize the unsteady events. A thorough analysis based on the wall pressure fluctuations disclosed that the large-scale vortical structure shedding at the frequency of fH/Uo = 0.064 gave a primary contribution to the wall pressure fluctuations, and consequently dominated unsteady behaviors of the turbulent shear layer. The convection velocity of the large-scale vortical structure was determined as Uc =0.55 U0. The instantaneous flow visualizations and wall pressure were compared in a straightforward manner. Below the separation bubble and the reattachment zone, the negative peak of the time-varying wall pressure was in phase with passage of the local large-scale vortical structure. In the redeveloping turbulent boundary layer, the decaying large-scale vortical structure was clearly revealed.

关键词： backward-facing step large-scale vorticalstructure visualization wall pressure fluctuations

Effects of 105 traditional Chinese medicines on the detection ofβ-agonists in medicine extracts and swine urine based on colloidal gold immunochromatographic assay

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Journal of Integrative Agriculture 2021年第6期20卷 1626-1635页

作者： WANG Zi-lin feng ke-ying GE Xiu-feng MAI Jia-cheng WANG Han-chuan LIU Wen-zi ZHANG Jia-hui SHEN Xiang-guang Guangdong Provincial key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation South China Agricultural UniversityGuangzhou 510642P.R.China Animal and Poultry Products Quality Control Inspection and Testing CenterMinistry of Agriculture and Rural AffairsGuangzhou 510642P.R.China

Colloidal gold immunochromatographic assay(CGIA)is commonly used for the on-site detection ofβ-agonists that are sometimes used illegally as feed additives in swine ***,few studies have evaluated the causes of false-positive results that sometimes occur when applying CGIA in agricultural *** this study,we investigated if this false-positive phenomenon is related to the addition of certain traditional Chinese medicines(TCMs)to swine *** established and verified an extraction method for TCMs,and then applied CGIA to detectβ-agonists in the extracts of 105 TCMs and in the urine of swine dosed with TCMs,*** chromatography-tandem mass spectrometry was used to validate the results of the urine samples tested positive forβ-agonists using *** results were also verified using TCMs and colloidal gold test strips produced by different *** extracts of Citri Reticulatae Pericarpium Viride,Citri Reticulatae Pericarpium,Magnoliae Officinalis Cortex,Chaenomelis Fructus,and Rhodiolae Crenulatae Radix Et Rhizoma were tested positive forβ-***,the addition of Citri Reticulatae Pericarpium Viride and Citri Reticulatae Pericarpium to swine feed resulted in false-positive results forβ-agonists in swine *** results provide a new way to explain false-positive CGIA results and provide valuable information for livestock feeding programs.

关键词： colloidal gold immunochromatographic assay false positive traditional Chinese medicine β-agonists swine urine

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农业创业教育培训不同模式效果比较分析

湖北农业科学 2014年第18期53卷 4505-4510页

作者：邓娜汪发元柯凤英孙文学长江大学经济学院湖北荆州434023 长江大学管理学院湖北荆州434023 湖北省农业厅科教处武汉430070 长江大学农学院湖北荆州434023

农业创业教育培训是实行城乡一体化的重要举措,为了进一步优化农业创业培训,提升培训效果,采用跟踪调查方法和比较分析法对农业创业培训模式效果进行调查分析。结果显示,不同培训模式的培训效果存在较大差异。纯理论课讲授模式、理论讲... 详细信息

农业创业教育培训是实行城乡一体化的重要举措,为了进一步优化农业创业培训,提升培训效果,采用跟踪调查方法和比较分析法对农业创业培训模式效果进行调查分析。结果显示,不同培训模式的培训效果存在较大差异。纯理论课讲授模式、理论讲授加考察模式效果有限,把创业理论和创业实践结合起来的"三阶段六环节"模式具有项目选择上的针对性、项目运作上的操作性,培训效果更加显著。为此,应当完善培训模式,不断提升培训效果;加强培训团队建设,促进农民创业发展;健全绩效考核机制,调动各方推广热情;不断实践和完善农业创业培训模式,切实提高培训实效,促进农民增产增收,带动农村经济社会协调发展。

关键词：农业创业培训模式比较建议

Hypoxia-preconditioned bone marrow-derived mesenchymal stem cells protect neurons from cardiac arrest-induced pyroptosis

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Neural Regeneration Research 2025年第4期20卷 1103-1123页

作者： Xiahong Tang Nan Zheng Qingming Lin Yan You Zheng Gong Yangping Zhuang Jiali Wu Yu Wang Hanlin Huang Jun ke feng Chen Shengli Clinical Medical College of Fujian Medical University Fujian Medical UniversityFuzhouFujian ProvinceChina Department of Emergency Fujian Provincial HospitalFuzhouFujian ProvinceChina Fujian Provincial key Laboratory of Emergency Medicine FuzhouFujian ProvinceChina The Second Department of Intensive Care Unit Fujian Provincial Hospital South BranchFuzhouFujian ProvinceChina

Cardiac arrest can lead to severe neurological impairment as a result of inflammation,mitochondrial dysfunction,and post-cardiopulmonary resuscitation neurological *** preconditioning has been shown to improve migration and survival of bone marrow–derived mesenchymal stem cells and reduce pyroptosis after cardiac arrest,but the specific mechanisms by which hypoxia-preconditioned bone marrow–derived mesenchymal stem cells protect against brain injury after cardiac arrest are *** this end,we established an in vitro co-culture model of bone marrow–derived mesenchymal stem cells and oxygen–glucose deprived primary neurons and found that hypoxic preconditioning enhanced the protective effect of bone marrow stromal stem cells against neuronal pyroptosis,possibly through inhibition of the MAPK and nuclear factor κB ***,we transplanted hypoxia-preconditioned bone marrow–derived mesenchymal stem cells into the lateral ventricle after the return of spontaneous circulation in an 8-minute cardiac arrest rat model induced by *** results showed that hypoxia-preconditioned bone marrow–derived mesenchymal stem cells significantly reduced cardiac arrest–induced neuronal pyroptosis,oxidative stress,and mitochondrial damage,whereas knockdown of the liver isoform of phosphofructokinase in bone marrow–derived mesenchymal stem cells inhibited these *** conclude,hypoxia-preconditioned bone marrow–derived mesenchymal stem cells offer a promising therapeutic approach for neuronal injury following cardiac arrest,and their beneficial effects are potentially associated with increased expression of the liver isoform of phosphofructokinase following hypoxic preconditioning.

关键词： bone marrow–derived mesenchymal stem cells cardiac arrest cardiac resuscitation hypoxic preconditioning liver isoform of phosphofructokinase mitochondria neuroinflammation oxidative stress pyroptosis reactive oxygen species

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基于Hough变换的挡键丢失故障识别方法

微电子学与计算机 2017年第3期34卷 90-94页

作者：艾广张金敏王思明冯映科兰州交通大学机电工程学院甘肃兰州730070 兰州交通大学自动化与电气工程学院甘肃兰州730070

为了检测货车运行故障动态检测系统(Trouble of Moving Freight Car Detection System,TFDS)中的挡键丢失故障,提出一种基于Hough变换的挡键丢失故障识别方法.首先采用改进的随机Hough变换提取轮轴和端点的特征,依据轮轴、端点、挡键之... 详细信息

为了检测货车运行故障动态检测系统(Trouble of Moving Freight Car Detection System,TFDS)中的挡键丢失故障,提出一种基于Hough变换的挡键丢失故障识别方法.首先采用改进的随机Hough变换提取轮轴和端点的特征,依据轮轴、端点、挡键之间的几何关系建立数学模型标定感兴趣区域(ROI),然后计算ROI的相对梯度直方图特征,利用角度距离相似性度量实现挡键丢失故障的识别.实验结果表明,该方法可以识别不同类型转向架的挡键丢失故障,同时平均故障识别率达到94%.

关键词： TFDS 挡键 Hough变换相对梯度直方图特征故障识别

Observation of acoustic hybrid topological phases induced by the p-d orbital interactions

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Science China(Physics,Mechanics & Astronomy) 2025年第1期Mechanics & Astronomy) .卷 132-139页

作者： Xiao Xiang feng Gao Yu-Gui Peng Peng Wu Zong-Lin Li Xue-feng Zhu School of Physics and Innovation Institute Huazhong University of Science and Technology

In spinless systems,growing attention has recently been attracted to synthetic gauge fields,which redefine the fundamental crystal symmetries by utilizing the projective algebraic ***,synthetic gauge fields have been commonly investigated in single orbital systems,and explorations on hybrid orbitals remain elusive in ***,we report the experimental observation of hybrid topological phases induced by hybrid synthetic gauge flux,which is formed by the interaction between p and d orbitals embedded in acoustic *** breaking the translation symmetries of Lxand/or Ly,we unambiguously demonstrate the first-order M?bius edge states and higher-order corner *** work establishes a platform for seeking exotic topological phases induced by hybrid-orbitals interactions and initializing the framework of hybrid-orbitalsrelated topological *** applications can be anticipated in scenarios such as high-quality sensing and robust wave trapping due to the stepwise energy distribution of the hybrid topological phase.

关键词： topological insulator synthetic gauge field projective symmetry corner states

Unraveling the mechanism of action of Shangxia Liangji formula for treating insomnia:a metabolomics and network pharmacology approach

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Traditional Medicine Research 2025年第2期10卷 16-29页

作者： Xia-Jie Quan Hao Liang Yong-Hong Tang Li Jiang Xiong-ying Ji feng-ying Zhang Ping Zhang Bo Ouyang Department of Information The Affiliated Nanhua HospitalHengyang Medical SchoolUniversity of South ChinaHengyang 421002China Department of Neurology The Affiliated Nanhua HospitalHengyang Medical SchoolUniversity of South ChinaHengyang 421002China Department of Gastroscopy The Affiliated Nanhua HospitalHengyang Medical SchoolUniversity of South ChinaHengyang 421002China Department of Traditional Chinese Medicine The Affiliated Nanhua HospitalHengyang Medical SchoolUniversity of South ChinaHengyang 421002China

Background:Insomnia is a prevalent clinical condition and Shangxia Liangji formula(SXLJF)is a well-established method of ***,the specific mechanism of action of SXLJF remains ***:The mouse model of insomnia was established by intraperitoneal injection of ***-two mice were randomly divided into a negative control group,model group,SXLJF group(18.72 g/kg/day),and positive control group(diazepam,2 mg/kg)and treated with the corresponding drugs for 7 consecutive *** open field test and pentobarbital-induced sleeping test were ***-MS-based untargeted metabolomics and network pharmacology were applied to explore the potential targets of SXLJF for treating ***,key targets were validated using ***:Behavioral tests demonstrated that SXLJF reduced the total distance,average velocity,central distance,and sleep latency,and prolonged sleep *** and network pharmacology revealed potential targets,signaling pathways,metabolic pathways,and metabolites associated with the anti-insomnia effects of ***,tyrosine hydroxylase(TH)and tyrosine metabolism emerged as crucial metabolic pathways and targets,***-qPCR results supported the role of TH in the mechanism of SXLJF in treating ***:In conclusion,TH and tyrosine metabolism may represent significant targets and pathways for SXLJF in treating insomnia.

关键词： Shangxia Liangji formula insomnia metabolomics network pharmacology tyrosine hydroxylase tyrosine metabolism

An Efficient Boron Source Activation Strategy for the Low‑Temperature Synthesis of Boron Nitride Nanotubes

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Nano-Micro Letters 2025年第1期17卷 548-558页

作者： ying Wang Kai Zhang Liping Ding Liyun Wu Songfeng E Qian He Nanyang Wang Hui Zuo Zhengyang Zhou feng Ding Yue Hu Jin Zhang Yagang Yao National Laboratory of Solid State Microstructures College of Engineering and Applied SciencesJiangsu Key Laboratory of Artificial Functional Materialsand Collaborative Innovation Center of Advanced MicrostructuresNanjing UniversityNanjing 210093People’s Republic of China School of Electronic Information and Artificial Intelligence Shaanxi University of Science&TechnologyXian 710000People’s Republic of China College of Bioresources Chemical and Materials Engineering Shaanxi University of Science&TechnologyXian 710000People’s Republic of China key Laboratory of Carbon Materials of Zhejiang Province College of Chemistry and Materials EngineeringWenzhou UniversityWenzhou 325000People’s Republic of China Shenzhen Institutes of Advanced Technology Chinese Academy of SciencesShenzhen 518000People’s Republic of China College of Chemical and Molecular Engineering Peking UniversityBeijing 100871People’s Republic of China

Lowering the synthesis temperature of boron nitride nanotubes(BNNTs)is crucial for their *** primary reason for adopting a high temperature is to enable the effective activation of highmelting-point solid *** this study,we developed a novel approach for efficiently activating boron by introducing alkali metal compounds into the conventional MgO–B *** approach can be adopted to form various low-melting-point AM–Mg–B–O growth *** growth systems have improved catalytic capability and reactivity even under low-temperature conditions,facilitating the synthesis of BNNTs at temperatures as low as 850℃.In addition,molecular dynamics simulations based on density functional theory theoretically demonstrate that the systems maintain a liquid state at low temperatures and interact with N atoms to form BN *** findings offer novel insights into the design of boron activation and are expected to facilitate research on the low-temperature synthesis of BNNTs.

关键词： Boron nitride nanotubes Low-temperature Boron activation Density functional theory