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Numerical investigation of Reynolds number and scaling effects in microchannels flows

Journal of Hydrodynamics 2017年第4期29卷 647-658页

作者： s.a.si sa.a. E.G.Filali s.Djellouli Faculty of Mechanical and Process Engineering Houari Boumedienne University

Compared with conventional channels, experiments of microchannel often exhibit some controversial findings and sometimes even opposite trends, most notably the effects of the Reynolds number and the scaled channel height on the Poiseuille number. The experimental method has still been constrained by two key facts, firstly the current ability to machine microstructures and secondly the limitation of measurement of parameters related to the Poiseuille number. As a consequence, numerical method was adopted in this study in order to analyze a flow in two-dimensional rectangular microchannels using water as working fluid. Results are obtained by the solution of the steady laminar incompressible Navier-stokes equations using control volume finite element method（CVFEM） without pressure correction. The computation was made for channel height ranging from 50 ？m to 4.58 ？m and Reynolds number varying from 0.4 to 1 600. The effect of Reynolds number and channel heights on flow characteristics was investigated. The results showed that the Poiseuille numbers agree fairly well with the experimental measurements proving that there is no scale effect at small channel height. This scaling effect has been confirmed by two additional simulations being carried out at channel heights of 2.5 ？m and 0.5 ？m, respectively and the range of Reynolds number was extended from 0.01 up to 1 600. This study confirm that the conventional analysis approach can be employed with confidence for predicting flow behavior in microchannels when coupled with carefully matched entrance and boundary conditions in the dimensional range considered here.

关键词： Rectangular microchannel Poiseuille number control volume finite element method(CVFEM) laminar flow minichannels

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Unraveling brain aging through the lens of oral microbiota

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Neural Regeneration Research 2025年第7期20卷 1930-1943页

作者： Qinchao Hu si Wang Weiqi Zhang Jing Qu Guang-Hui Liu state Key Laboratory of Membrane Biology Institute of ZoologyChinese Academy of SciencesBeijingChina Hospital of stomatology Guanghua School of StomatologyGuangdong Provincial Key Laboratory of StomatologySun Yat-sen UniversityGuangzhouGuangdong ProvinceChina Advanced Innovation Center for Human Brain Protection and National Clinical Research Center for Geriatric Disorders Xuanwu HospitalCapital Medical UniversityBeijingChina Aging Translational Medicine Center International Center for Aging and CancerBeijing Municipal Geriatric Medical Research CenterXuanwu HospitalCapital Medical UniversityBeijingChina CAs Key Laboratory of Genomic and Precision Medicine Beijing Institute of GenomicsChinese Academy of Sciences and China National Center for BioinformationBeijingChina University of Chinese Academy of sciences BeijingChina Institute for stem Cell and Regeneration Chinese Academy of SciencesBeijingChina Aging Biomarker Consortium BeijingChina state Key Laboratory of stem Cell and Reproductive Biology Institute of ZoologyChinese Academy of SciencesBeijingChina Beijing Institute for stem Cell and Regenerative Medicine BeijingChina

The oral cavity is a complex physiological community encompassing a wide range of *** of oral microbiota can lead to various oral infectious diseases,such as periodontitis and tooth decay,and even affect systemic health,including brain aging and neurodegenerative *** studies have highlighted how oral microbes might be involved in brain aging and neurodegeneration,indicating potential avenues for intervention *** this review,we summarize clinical evidence demonstrating a link between oral microbes/oral infectious diseases and brain aging/neurodegenerative diseases,and dissect potential mechanisms by which oral microbes contribute to brain aging and *** also highlight advances in therapeutic development grounded in the realm of oral microbes,with the goal of advancing brain health and promoting healthy aging.

关键词： Alzheimer's disease brain aging multiple sclerosis neurodegeneration neurodegenerative diseases oral microbiota Parkinson's disease periodontitis bacteria Porphyromonas gingivalis

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High Fe‑Loading single‑Atom Catalyst Boosts ROs Production by Density Effect for Efficient Antibacterial Therapy

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Nano-Micro Letters 2025年第2期17卷 187-203页

作者： si Chen Fang Huang Lijie Mao Zhimin Zhang Han Lin Qixin Yan Xiangyu Lu Jianlin shi Department of Cardiology Shanghai Tenth People’s HospitalSchool of MedicineTongji UniversityShanghai 200092People’s Republic of China shanghai Institute of Ceramics Chinese Academy of SciencesShanghai 200050People’s Republic of China shanghai Frontiers science Center of Nanocatalytic Medicine School of MedicineTongji UniversityShanghai 200092People’s Republic of China

The current single-atom catalysts(saCs)for medicine still suffer from the limited active site ***,we develop a synthetic method capable of increasing both the metal loading and mass-specific activity of saCs by exchanging zinc with *** constructed iron saCs(h^(3)-FNC)with a high metal loading of 6.27 wt%and an optimized adjacent Fe distance of~4 A exhibit excellent oxidase-like catalytic performance without significant activity decay after being stored for six months and promising antibacterial ***,a“density effect”has been found at a high-enough metal doping amount,at which individual active sites become close enough to interact with each other and alter the electronic structure,resulting in significantly boosted intrinsic activity of single-atomic iron sites in h^(3)-FNCs by 2.3 times compared to low-and medium-loading ***,the overall catalytic activity of h^(3)-FNC is highly improved,with mass activity and metal mass-specific activity that are,respectively,66 and 315 times higher than those of commercial Pt/*** addition,h^(3)-FNCs demonstrate efficiently enhanced capability in catalyzing oxygen reduction into superoxide anion(O_(2)·^(−))and glutathione(GsH)*** in vitro and in vivo assays demonstrate the superior antibacterial efficacy of h^(3)-FNCs in promoting wound *** work presents an intriguing activity-enhancement effect in catalysts and exhibits impressive therapeutic efficacy in combating bacterial infections.

关键词： Nanocatalytic medicine single-atom catalysts Reactive oxygen species(ROs) High metal loading Oxidase catalysis

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NOX4 exacerbates Parkinson's disease pathology by promoting neuronal ferroptosis and neuroinflammation

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Neural Regeneration Research 2025年第7期20卷 2038-2052页

作者： Zhihao Lin Changzhou Ying Xiaoli si Naijia Xue Yi Liu Ran Zheng Ying Chen Jiali Pu Baorong Zhang Department of Neurology The Second Affiliated HospitalZhejiang University School of MedicineHangzhouZhejiang ProvinceChina

Parkinson's disease is primarily caused by the loss of dopaminergic neurons in the substantia nigra ***,a novel form of regulated cell death characterized by iron accumulation and lipid peroxidation,plays a vital role in the death of dopaminergic ***,the molecular mechanisms underlying ferroptosis in dopaminergic neurons have not yet been completely *** oxidase 4 is related to oxidative stress,however,whether it regulates dopaminergic neuronal ferroptosis remains *** aim of this study was to determine whether NADPH oxidase 4 is involved in dopaminergic neuronal ferroptosis,and if so,by what *** found that the transcriptional regulator activating transcription factor 3 increased NADPH oxidase 4 expression in dopaminergic neurons and astrocytes in an 1-methyl-4-phenyl-1,2,3,6 tetrahydropyridine-induced Parkinson's disease *** oxidase 4 inhibition improved the behavioral impairments observed in the Parkinson's disease model animals and reduced the death of dopaminergic ***,NADPH oxidase 4 inhibition reduced lipid peroxidation and iron accumulation in the substantia nigra of the Parkinson's disease model ***,we found that NADPH oxidase 4 interacted with activated protein kinase Cαto prevent ferroptosis of dopaminergic ***,by lowering the astrocytic lipocalin-2 expression,NADPH oxidase 4 inhibition reduced 1-methyl-4-phenyl-1,2,3,6 tetrahydropyridine-induced *** findings demonstrate that NADPH oxidase 4 promotes ferroptosis of dopaminergic neurons and neuroinflammation,which contribute to dopaminergic neuron death,suggesting that NADPH oxidase 4 is a possible therapeutic target for Parkinson's disease.

关键词： dopaminergic neuron ferroptosis NADPH oxidase 4(NOX4) neuroinflammation Parkinson's disease

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阿列克谢耶夫《聊斋志异》译本的译者行为批评分析

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外语学刊 2025年第1期 92-98页

作者：雷丽斯黑龙江大学高级翻译学院哈尔滨150080

《聊斋志异》是我国古代短篇小说的艺术丰碑,由苏联汉学家阿列克谢耶夫完成的俄语选译本在俄罗斯完成经典化。本文以阿列克谢耶夫译本为例,运用文本细读法,从翻译内外二分化视野,对译者行为进行批评分析。研究发现,在翻译外层面上,译者... 详细信息

《聊斋志异》是我国古代短篇小说的艺术丰碑,由苏联汉学家阿列克谢耶夫完成的俄语选译本在俄罗斯完成经典化。本文以阿列克谢耶夫译本为例,运用文本细读法,从翻译内外二分化视野,对译者行为进行批评分析。研究发现,在翻译外层面上,译者身份、译者与作者之间的“知己关系”等因素促使译者行为偏向作者/原文一端;在翻译内层面上,译者运用多种翻译手段最大限度地实现了对作者/原文的求真,同时在求真的基础上,使译文对读者/社会务实,译者行为合理度较佳。

关键词：译者行为批评《聊斋志异》阿列克谢耶夫译者行为典籍翻译

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Coalescence suppression in Flowing Polymer Blends Using silica Rods with Different surface Chemistries

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Chinese Journal of Polymer science 2021年第4期39卷 474-483,I0007页

作者： si-Ying Xiang Li-sa-Ya Ye Ya-Jiang Huang Ya-Dong Lv Mi-Qiu Kong Guang-Xian Li College of Polymer science and Engineering State Key Laboratory of Polymer Materials Engineering of ChinaSichuan UniversityChengdu 610065China

silica rods with homogeneous(hydrophilic or hydrophobic)and amphiphilic surface properties were synthesized and their efficiencies in suppressing the flow-induced droplet coalescence of immiscible polyisobutylene(PIB)/polydimethylsiloxane(PDMs)blends were evaluated via in situ visualization *** flow-induced coalescence behavior of blends was found to strongly depend on the surface nature and concentration of silica rods added as well as the blend *** a trace amount of rods promoted coalescence,all kinds of rods demonstrated a morphology refinement effect at high rod *** compatibilization effects were obtained at high rod concentrations,especially for hydrophilic and amphiphilic *** on confocal laser scanning microscopy results,these phenomena observed were interpreted reasonably in terms of the selective distribution and aggregation of silica rods,which were suggested to be decisive for the stabilization mechanism and efficiency of these rods.

关键词： Immiscible polymer blends Flow Morphology silica rods surface chemistry

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Relationship between virological response and FIB-4 index in chronic hepatitis B patients with entecavir therapy

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World Journal of Gastroenterology 2015年第43期21卷 12421-12429页

作者： Ni Li Jing-Hang Xu Min Yu sa Wang Chong-Wen si Yan-Yan Yu Department of Infectious Diseases Peking University First Hospital

AIM: To investigate whether long-term low-level hepatitis B virus(HBV) DNA influences dynamic changes of the FIB-4 index in chronic hepatitis B(CHB) patients receiving entecavir(ETV) therapy with partial virological ***: We retrospectively analyzed 231 nucleos-(t)ide(NA) na?ve CHB patients from our previous study(NCT01926288) who received continuous ETV or ETV maleate therapy for three years. The patients were divided into partial virological response(PVR) and complete virological response(CVR) groups according to serum HBV DNA levels at week 48. seventy-six patients underwent biopsies at baseline and at 48 wk. The performance of the FIB-4 index and area under the receiver operating characteristic(AUROC) curve for predicting fibrosis were determined for the patients undergoing biopsy. The primary objective of the study was to compare the cumulative probabilities of virological responses between the two groups during the treatment period. The secondary outcome was to observe dynamic changes of the FIB-4 index between CVR patients and PVR ***: For hepatitis B e antigen(HBe Ag)-positive patients(n = 178),the cumulative probability of achieving undetectable levels at week 144 was 95%and 69% for CVR and PVR patients,respectively(P s model,a lower pretreatment serum HBV DNA level was an independent factor predicting maintained viral suppression. The cumulative probability of achieving undetectable levels of HBV DNA for HBe Ag-negative patients(n = 53) did not differ between the two groups. The FIB-4 index efficiently identified fibrosis,with an AUROC of 0.80(95%CI: 0.69-0.89). For HBe Ag-positive patients,the FIB-4 index was higher in CVR patients than in PVR patients at baseline(1.89 ± 1.43 vs 1.18 ± 0.69,P s no significant difference in the reduction of the FIB-4 index between the CVR and PVR groups from weeks 48 to 144(-0.11 ± 0.47 vs-0.13 ± 0.49,P = 0.71). At week 144,the FIB-4 index

关键词： Chronic hepatitis B Hepatitis B virus DNA Entecavi

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Research on the Internal Mechanism,Model,and Effectiveness of Online Deep Learning

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Frontiers of Education in China 2023年第3期18卷 310-331页

作者： BU Caili LI sa YANG Haihui WANG Limin ZHANG Tong ZHANG si Department of Education Henan Normal UniversityXinxiang 453007China Primary school Affiliated to Henan Normal University Xinxiang 453007China Faculty of Artificial Intelligence Education Central China Normal UniversityWuhan 430079China

With the in-depth development of internet plus education and the COVID-19 pandemic,online learning has become a universal teaching method in the ***,the issue of superficial and low-quality in online learning is still *** the internal and external conditions of online deep learning,this study reveals the theory mechanism of how the online learning environment and teacher support,as external conditions,affect students’emotions and learning motivation,and then affect students’internal learning *** this basis,an online deep teaching model is constructed,which consists of three stages:online asynchronous self-study before class,online synchronous live broadcasting teaching in class,and online asynchronous expansion after ***,a one-term long online teaching practice is carried out in the course named the Instructional system *** results show that,in the learning process level,the online deep teaching model can effectively improve students’online learning engagement,promote students to use deep learning methods and deep learning motivation to learn,and enhance the depth of online interaction between *** the level of learning results,students’critical thinking and online academic performance 9 have been significantly improved.

关键词： online learning online deep learning internal mechanism teaching model teaching effectiveness

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EXPECTED NUMBER OF ITERATIONs OF INTERIOR-POINT ALGORITHMs FOR LINEAR PROGRAMMING

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Journal of Computational Mathematics 2005年第1期23卷 93-100页

作者： si-mingHuang InstituteofPolicyandManagement ChineseAcademyofScienceBeijing100080China

We study the behavior of some polynomial interior-point algorithms for solving random linear programming (LP) problems. We show that the expected and anticipated number of iterations of theseTodd's probabilisticalgori... 详细信息

关键词： linear programming lnterior point algorithms probabilistic LP models expected number of iterations

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中国乡镇教育行政机构发展历程、运行模式及变革走向

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北京教育学院学报 2025年第1期39卷 1-8页

作者：司洪昌韩烨国家教育行政学院科研处北京102617 国家教育行政学院教育行政教研部北京102617

自新中国成立以来,乡镇教育行政机构经历了从隶属于乡镇政府到隶属于县教育局的转变。2002年起,乡镇教育行政机构归属于县教育局垂直管理,这一体制运行至今,各地乡镇教育行政机构名称复杂而多元,且存在多样化的模式。乡镇教育行政机构... 详细信息

自新中国成立以来,乡镇教育行政机构经历了从隶属于乡镇政府到隶属于县教育局的转变。2002年起,乡镇教育行政机构归属于县教育局垂直管理,这一体制运行至今,各地乡镇教育行政机构名称复杂而多元,且存在多样化的模式。乡镇教育行政机构的地方属性,给乡镇教育管理预留了政策空间。当前乡镇教育行政机构重构的窗口期已开启,各地根据区域方位、县域及乡镇面积大小与人口多少、居民点分布及经济发展水平等做出适应地方实际的动态调整,成为未来十年的一个重要趋势。

关键词：乡镇教育教育行政机构乡镇中心校

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