检索结果-南通市图书馆

在线全文

学校读者我要写书评

暂无评论

微纳尺度流动与界面流动专题序

力学学报 2024年第5期56卷 1211-1213页

作者：关东石司廷中国科学院力学研究所非线性力学国家重点实验室北京100190 中国科学院大学工程科学学院北京100049 中国科学技术大学近代力学系合肥230027

微纳尺度流动与界面流动是流体力学的重要分支学科[1],其中微纳尺度流动关注微米、亚微米乃至纳米尺度下流体运动及物质输运规律,界面流动关注不同流体或流固界面之间的相互作用及流动规律.随着微流控芯片和微纳机电系统的发展,微纳尺... 详细信息

微纳尺度流动与界面流动是流体力学的重要分支学科[1],其中微纳尺度流动关注微米、亚微米乃至纳米尺度下流体运动及物质输运规律,界面流动关注不同流体或流固界面之间的相互作用及流动规律.随着微流控芯片和微纳机电系统的发展,微纳尺度流动与界面流动已成为流体力学学科的重要前沿领域,并且涉及了流体力学与生命科学、材料科学、医疗健康、能源环境、先进制造等多学科领域的交叉融合.

关键词：微纳尺度微流控芯片流体力学医疗健康流体运动交叉融合能源环境生命科学

在线全文

学校读者我要写书评

暂无评论

探索微纳米世界的手——原子力显微镜

力学与实践 2021年第5期43卷 806-811页

作者：李航宇聂鹏程关东石中国科学院大学工程科学学院北京100049 中国科学院力学研究所非线性力学国家重点实验室北京100190

显微镜的发展让人类看到了真实的微纳米世界,原子力显微镜的出现则让我们进一步直接接触并感知其中的力学相互作用。借助这只微纳尺度的手,原子力显微镜技术越来越多地帮助我们探索和理解微纳米世界,甚至是生命世界。本文介绍了显微镜... 详细信息

显微镜的发展让人类看到了真实的微纳米世界,原子力显微镜的出现则让我们进一步直接接触并感知其中的力学相互作用。借助这只微纳尺度的手,原子力显微镜技术越来越多地帮助我们探索和理解微纳米世界,甚至是生命世界。本文介绍了显微镜的发展,原子力显微镜的力学测量原理,以及在活细胞力学研究中的应用。

关键词：原子力显微镜微纳米尺度弹性模量细胞力学

探索微纳尺度润湿动力学:长针式原子力显微镜的应用与进展

在线全文

学校读者我要写书评

暂无评论

力学学报 2024年第6期56卷 1497-1510页

作者：关东石聂鹏程闫财山郭永杰童彭尔中国科学院力学研究所非线性力学国家重点实验室北京100190 中国科学院大学工程科学学院北京100049 香港科技大学物理系中国香港999077

“如何在微观层面测量界面现象”是微纳尺度实验流体力学的关键科学问题,被列入世界前沿125个科学问题名单(Sanders S,Science,2021).由于光学衍射极限的限制,传统光学手段很难直接测量微纳尺度下的流动与界面现象.利用原子力显微镜的... 详细信息

“如何在微观层面测量界面现象”是微纳尺度实验流体力学的关键科学问题,被列入世界前沿125个科学问题名单(Sanders S,Science,2021).由于光学衍射极限的限制,传统光学手段很难直接测量微纳尺度下的流动与界面现象.利用原子力显微镜的精准操控和小尺度力学测量等优势,结合长针式探针组装成的微流变计可以直接测量气-液-固三相接触线上的毛细力,并监测探针在垂直方向运动中力的动态变化.通过该技术手段,可以实现对流体界面的动力学行为以及各类材料在液体环境中力学性质在微纳尺度的精确表征.文章将系统介绍长针式原子力显微镜技术的实验原理和方法,及其在微纳尺度非理想界面润湿动力学中的最新研究进展,包括低能垒表面毛细力的速度依赖性与非对称性、无序粗糙表面接触线黏滑运动的统计学规律、柔性表面接触线动力学的状态与速度定律、以及离子液体-金属界面处电场对接触角迟滞的调控等,最后展望了该技术在新兴领域中的应用.该实验手段为检验各类理论模型与数值模拟提供了可信数据,为探究界面上复杂现象的物理本质提供参考.

关键词：微纳尺度流动与界面流动三相接触线润湿动力学原子力显微镜流固界面

Molecular dynamics simulations of helium transport through inorganic mineral nanopores

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 2025年第1期68卷 237-252页

作者： Dandan SONG Ping guan Chi ZHANG Jiahao REN School of Earth and Space Sciences Peking University

Helium transport through nanoscale inorganic mineral pores and pore throats is essential for its overall migration. To elucidate helium's transport dynamics within nanopores, we employed equilibrium and non-equilibrium molecular dynamics simulations to investigate helium's static self-diffusion and pressure-driven flow in quartz slit-shaped nanopores. We also introduced water and various gases, including hydrogen, methane, ethane, nitrogen, and carbon dioxide, into the nanopores to assess their influence on helium transport. Our findings indicate minimal helium adsorption on quartz pore surfaces. Under conditions where the pore size is less than 5 nm and the pressure under 10 MPa, environmental factors markedly influence helium diffusion. Large pore sizes, high temperatures, and low gas pressures enhance helium desorption and facilitate faster diffusion. We observed a positive correlation between helium flow velocity and factors such as pore size, pressure gradient, and surface smoothness of the pores. Notably, the presence of pore water and carrier gases in quartz nanopores, which diffuse more slowly than helium, tends to reduce helium surface adsorption and slow its diffusion. Among the carrier gases studied, nitrogen showed similar adsorption capacity, diffusivity, and stability to helium, while carbon dioxide displayed the highest adsorption capacity and the slowest diffusion rate, markedly differing from helium. Based on the simulation results, we concluded that water and carrier gases primarily function as transport mediums in helium migration, moving together with helium. Nitrogen, which shares similar properties with helium, effectively assists in this co-migration process. Conversely, carbon dioxide, due to its high adsorption capacity and slow diffusion, tends to be lost during co-migration. As a result, gas reservoirs with high nitrogen levels and low carbon dioxide levels are more likely to have higher helium concentrations. Additionally, the smaller por

关键词： Helium transport Slit nanopores Molecular dynamics simulations Diffusion Flow carriers

Enhancing insights into Global Cancer Statistics 2022: implications for cancer control

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science China Life Sciences 2025年第1期68卷 294-296页

作者： Jingtong Xu Runtian Wang Xiaoxiang guan Department of Oncology the First Affiliated Hospital of Nanjing Medical University Jiangsu Key Lab of Cancer Biomarkers Prevention and TreatmentCollaborative Innovation Center for Personalized Cancer MedicineNanjing Medical University

Globally, there has been a marked escalation in tumor morbidity and mortality,cementing tumors as the predominant cause of death in numerous *** the current tumor burden across various regions is imperative to discern potential risk factors and formulate efficacious strategies for tumor ***, the International Agency for Research on Cancer(IARC) provided a status report on the global tumor burden,estimating the incidence and mortality of 36 cancers in 185 countries(Bray et al.,2024).

关键词：

姜黄素对大鼠肝脏冷缺血再灌注损伤的保护作用及其机制

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

中国普通外科杂志 2010年第1期19卷 32-36页

作者：安伟刘军管冬诗杨凤辉许世峰周旭山东大学附属省立医院器官移植中心肝胆外二科山东济南250021

目的探讨姜黄素预处理对大鼠肝脏冷缺血再灌注损伤(IRI)的保护作用及其机制。方法将40只Wistar大鼠随机分为:实验组(21只),于术前2 h将60 mg/kg的姜黄素溶于1mL DMSO中静脉注射;对照组(19只),于术前2h静脉注射1 mL DMSO。肝脏冷灌注时间... 详细信息

目的探讨姜黄素预处理对大鼠肝脏冷缺血再灌注损伤(IRI)的保护作用及其机制。方法将40只Wistar大鼠随机分为:实验组(21只),于术前2 h将60 mg/kg的姜黄素溶于1mL DMSO中静脉注射;对照组(19只),于术前2h静脉注射1 mL DMSO。肝脏冷灌注时间为30 min,恢复血供复流6 h后处死动物,留取血液和肝脏标本,行血清ALT,AST,LDH和组织匀浆SOD,MDA,MPO测定,并进行组织病理和细胞凋亡检测。酶联免疫吸附试验(ELISA)检测肝组织匀浆中TNF-α及MIP-2的水平变化。结果实验组大鼠血清ALT,AST,LDH水平明显低于对照组(P<0.01);实验组MDA,MPO,TNF-α和MIP-2水平较对照组明显降低(P<0.05),SOD含量较对照组明显增高(P<0.05)。并且实验组大鼠肝组织损伤程度和细胞凋亡程度明显轻于对照组。结论姜黄素预处理能减轻大鼠肝脏冷IRI,其保护机制可能与提高肝组织SOD含量,抑制脂质过氧化与细胞凋亡,下调炎性因子TNF-α和MIP-2的表达以及减少中性粒细胞浸润有关。

关键词：再灌注损伤肝姜黄素大鼠

饮食中亚硝酸盐对大鼠肝缺血再灌注损伤的保护作用

在线全文

学校读者我要写书评

暂无评论

中国普通外科杂志 2011年第1期20卷 58-61页

作者：管冬诗杨凤辉安伟刘国梁郑元文刘军山东大学附属省立医院器官移植中心肝胆外二科山东济南250021

目的探讨饮食中亚硝酸盐对大鼠肝脏缺血再灌注(I/R)损伤的保护作用。方法 Wistar大鼠随机分为I/R组(对照组)、亚硝酸钠预处理组(实验组)和假手术组。建立大鼠肝脏部分I/R模型,实验组的饮水中加入少量亚硝酸盐并喂养7 d后建模,检测血清... 详细信息

目的探讨饮食中亚硝酸盐对大鼠肝脏缺血再灌注(I/R)损伤的保护作用。方法 Wistar大鼠随机分为I/R组(对照组)、亚硝酸钠预处理组(实验组)和假手术组。建立大鼠肝脏部分I/R模型,实验组的饮水中加入少量亚硝酸盐并喂养7 d后建模,检测血清谷丙转氨酶(ALT)和谷草转氨酶(AST)的水平,测定肝组织中超氧化物歧化酶(SOD),丙二醛(MDA),一氧化氮(NO),一氧化氮合酶(NOS)含量及活性。用Hoechst染色法检测细胞凋亡,并观察各组病理形态学的改变。结果对照组AST,ALT,MDA水平和细胞凋亡的程度均明显异常。实验组上述指标的异常变化均明显减轻,NO明显高于对照组,差异有统计学意义(P<0.01);但NOS并未增多,与对照组差异无统计学意义。结论饮食中的亚硝酸盐对大鼠肝脏I/R损伤有明显的保护作用。

关键词：再灌注损伤亚硝酸盐细胞凋亡一氧化氮

Decreased levels of phosphorylated synuclein in plasma are correlated with poststroke cognitive impairment

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2025年第9期20卷 2598-2610页

作者： Yi Wang Yuning Li Yakun Gu Wei Ma Yuying guan Mengyuan Guo Qianqian Shao Xunming Ji Jia Liu Department of Clinical Laboratory Beijing Bo’ai HospitalChina Rehabilitation Research CenterCapital Medical UniversityBeijingChina Beijing Institute of Brain Disorders Laboratory of Brain DisordersMinistry of Science and TechnologyCollaborative Innovation Center for Brain DisordersBeijing Advanced Innovation Center for Big Data-based Precision MedicineCapital Medical UniversityBeijingChina Department of Neurosurgery Xuanwu HospitalCapital Medical UniversityBeijingChina

Poststro ke cognitive impairment is a major secondary effect of ischemic stroke in many patients;however,few options are available for the early diagnosis and treatment of this *** aims of this study were to(1)determine the specific relationship between hypoxic andα-synuclein during the occur of poststroke cognitive impairment and(2)assess whether the serum phosphorylatedα-synuclein level can be used as a biomarker for poststro ke cognitive *** found that the phosphorylatedα-synuclein level was significantly increased and showed pathological aggregation around the cerebral infa rct area in a mouse model of ischemic *** addition,neuronalα-synuclein phosphorylation and aggregation were observed in the brain tissue of mice subjected to chronic hypoxia,suggesting that hypoxia is the underlying cause ofα-synuclein-mediated pathology in the brains of mice with ischemic *** phosphorylatedα-synuclein levels in patients with ischemic stroke were significantly lower than those in healt hy subjects,and were positively correlated with cognition levels in patients with ischemic ***,a decrease in serum high-density lipoprotein levels in stroke patie nts was significantly correlated with a decrease in phosphorylatedα-synuclein *** ischemic stroke mice did not show significant cognitive impairment or disrupted lipid metabolism 14 days after injury,some of them exhibited decreased cognitive function and reduced phosphorylatedα-synuclein *** together,our results suggest that serum phosphorylatedα-synuclein is a potential biomarker for poststroke cognitive impairment.

关键词： biomarker high-density lipoprotein ischemic stroke phosphorylatedα-synuclein poststroke cognitive impairment

Mechanistic insight into the synergy between nickel single atoms and nanoparticles on N-doped carbon for electroreduction of CO2

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2025年第1期100卷 327-336页

作者： Mingdong Sun Wenwen guan Cailing Chen Chao Wu Xiaoling Liu Biao Meng Tao Chen Yu Han Jun Wang Shibo Xi Yu Zhou State Key Laboratory of Materials-Oriented Chemical Engineering College of Chemical Engineering Nanjing Tech University Advanced Membranes and Porous Materials Center Physical Sciences and Engineering Division King Abdullah University of Science and Technology Institute of Sustainability for Chemicals Energy and Environment A*STAR (Agency for Science Technology and Research) College of Materials Science and Engineering Sichuan University

The synergy of single atoms （SAs） and nanoparticles （NPs） has demonstrated great potential in promoting the electrocatalytic carbon dioxide reduction reaction （CO2RR）;however,the rationalization of the SAs/NPs proportion remains one challenge for the catalyst ***,a Ni2+-loaded porous poly（ionic liquids）(PIL) precursor synthesized through the free radical self-polymerization of the ionic liquid monomer,1-allyl-3-vinylimidazolium chloride,was pyrolyzed to prepare the Ni,N co-doped carbon materials,in which the proportion of Ni SAs and NPs could be facilely modulated by controlling the annealing *** catalyst Ni-NC-1000 with a moderate proportion of Ni SAs and NPs exhibited high efficiency in the electrocatalytic conversion of CO2into *** Ni K-edge X-ray absorption near-edge structure （XANES） spectra and theoretical calculations were conducted to gain insight into the synergy of Ni SAs and *** charge transfer from Ni NPs to the surrounding carbon layer and then to the Ni SAs resulted in the electron-enriched Ni SAs active *** the electroreduction of CO2,the coexistence of Ni SAs and NPs strengthened the CO2activation and the affinity towards the key intermediate of*COOH,lowering the free energy for the potential-determining*CO2→*COOH step,and therefore promoted the catalysis efficiency.

关键词： Activation energy