检索结果-南通市图书馆

Nonlinear dynamics and manipulation of dripping in capillary flow focusing

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2019年第12期62卷 78-88页

作者： kai mu Ting Si Hang Ding Department of Modern Mechanics University of Science and Technology of China

In this study, we carried out experimental and numerical investigations on the dripping dynamics in axisymmetric capillary flow focusing. For the direct numerical simulations, we solved the Navier-Stokes equations coupled with a diffuse interface *** the experiments, we observed both periodic and non-periodic dripping modes at different focused and focusing liquid flow rates. The non-periodic dripping that results in polydispersed droplets downstream the orifice can be attributed to the nonlinear dynamics of the flow;thus, we constructed numerical plots of the streamlines and temporal evolutions of the focused liquid cone in different modes. We identified a phase diagram of the dripping regimes in the plane of mainly dimensionless parameters, which led us to further investigate the effects of liquid physical properties, such as viscosity and interface tension, on the mode *** suppression of the nonlinear dynamics, we proposed a geometrical optimization that imports a guiding rod positioning along the axis of the capillary tube. Here, we conducted a numerical analysis on the manipulation of the dripping process, as well as scaling analysis on the appearance of the nonlinear dripping. We expect this study to provide an insight into the underlying physical mechanisms of dripping in flow focusing, which are advantageous in the generation of monodispersed microdroplets for various applications.

关键词： flow focusing microdroplet dripping nonlinear dynamics

Ultrafast carrier dynamics of Cu_(2)O thin film induced by two-photon excitation

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2021年第11期30卷 348-351页

作者： Jian Liu Jing Li kai-Jun mu Xin-Wei Shi Jun-Qiao Wang Miao Mao Shu Chen Er-Jun Liang School of Physics and Microelectronics Zhengzhou UniversityZhengzhou 450001China

Cuprous oxide(Cu_(2)O)has attracted plenty of attention for potential nonlinear photonic applications due to its superior third-order nonlinear optical property such as two-photon *** this paper,we investigated the two-photon excitation induced carrier dynamics of a Cu_(2)O thin film prepared by radio-frequency magnetron sputtering,using the femtosecond transient absorption *** dynamics including an ultrafast carrier scattering(50 ps)were *** time constant of carrier scattering under two-photon excitation is larger than that under one-photon excitation,due to the different transition selection rules and smaller absorption coefficient of the two-photon excitation.

关键词： carrier dynamics cuprous oxide transient absorption two-photon absorption

在线全文

学校读者我要写书评

暂无评论

热场作用下液体射流的解析不稳定性理论

Acta Mechanica Sinica 2023年第10期39卷 42-57页

作者：乔然穆恺司廷 Department of Modern Mechanics University of Science and Technology of China Hefei 230026 China

本文研究了径向热场作用下静止气体环境内液体射流的线性时间不稳定性问题.通过求解射流与周围气体之间的热传导问题,得到基本温度分布.通过正则模方法求解小扰动随时间的演化,推导得到扰动增长的解析色散关系,并得到该解析色散关系的... 详细信息

本文研究了径向热场作用下静止气体环境内液体射流的线性时间不稳定性问题.通过求解射流与周围气体之间的热传导问题,得到基本温度分布.通过正则模方法求解小扰动随时间的演化,推导得到扰动增长的解析色散关系,并得到该解析色散关系的无粘渐近解.该无粘渐近解解耦了表面张力和Marangoni应力对射流失稳的贡献.通过参数研究,探究了不同控制参数对无粘液体射流扰动增长率的影响.结果表明,提高射流与周围气体的温度比、增强表面的Marangoni应力、减弱热传导效应或降低表面张力均可抑制射流不稳定性.此外,本工作对比了Rayleigh-Plateau不稳定性与Marangoni不稳定性对射流失稳过程的贡献.通过对比粘性射流扰动增长率与其无粘渐近解,确定了无粘渐近解的适用范围为雷诺数Re≥O(10^(2)).

关键词：液体射流渐近解色散关系气体环境周围气体不稳定性问题扰动增长率热传导问题

Morphine enhances purine nucleotide catabolism in vivo and in vitro

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Pharmacologica Sinica 2007年第8期28卷 1105-1115页

作者： Chang LIU Jian-kai LIU mu-jie KAN Lin GAO Hai-ying FU Hang ZHOU Min HONG~1 Department of Biochemistry and Molecular Biology,Basic Medical School,Jilin University,Jilin 130021,China Department of Biochemistry and Molecular Biology Basic Medical School Jilin University Jilin China

Aim:To investigate the effect and mechanism of morphine on purine ***:The rat model of morphine dependence and withdrawal andrat C6 glioma cells in culture were *** of uric acid in the plasmawere measured by the uricase-rap method,adenosine deaminase(ADA)and xan-thine oxidase(XO)in the plasma and tissues were measured by the ADA and XOtest ***-PCR and RT-PCR-Southern blotting were used to examine the relativeamount of ADA and XO gene transcripts in tissues and C6 ***:(i)theconcentration of plasma uric acid in the morphine-administered group was signifi-cantly higher(Pmuscles of the morphine-administered groupsincreased,while the level of ADA and XO in those tissues of the withdrawalgroups decreased;(iv)the transcripts of the ADA and XO genes in the parietallobe,liver,small intestine,and skeletal muscles were higher in the morphine-administered *** expression of the ADA and XO genes in those tissuesreturned to the control level during morphine withdrawal,with the exception of theskeletal muscles;and(v)the upregulation of the expression of the ADA and XOgenes induced by morphine treatment could be reversed by ***:The effects of morphine on purine nucleotide metabolism might be an important,new biochemical pharmacological mechanism of morphine action.

关键词： morphine uric acid purine nucleotide adenosine deaminase xanthine oxidase

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

毛细流动聚焦的实验方法及过程控制

实验流体力学 2020年第2期34卷 46-56页

作者：穆恺司廷中国科学技术大学近代力学系合肥230027

作为一种基于毛细流动制备微纳尺度液滴的技术,毛细流动聚焦(Capillary flow focusing)在工程领域具有重要应用。回顾了基于吹气式和吸气式核心装置的毛细流动聚焦实验方法,展示了完整的测试平台,介绍了施加外部激励控制流动聚焦射流破... 详细信息

作为一种基于毛细流动制备微纳尺度液滴的技术,毛细流动聚焦(Capillary flow focusing)在工程领域具有重要应用。回顾了基于吹气式和吸气式核心装置的毛细流动聚焦实验方法,展示了完整的测试平台,介绍了施加外部激励控制流动聚焦射流破碎的实验方法。同时,给出了同轴界面的拍摄方法,可获得清晰的内外层流体界面图像。在对流体锥形收缩阶段的研究中,探讨了几何参数与流动控制参数对流体锥形的形态与稳定性的影响。在稳定锥形下,研究了流动控制参数对液体射流直径、扰动波长及复合射流界面耦合的影响,并基于光的折射定律,对复合射流外层界面透镜效应所导致的内界面失真进行了修正。在对激励作用下射流破碎的研究中,考察了射流长度随振幅的变化,建立了尺度率关系,探讨了频率对生成液滴的单分散性及粒径的影响规律,为在实际应用中可控制备单分散性微液滴提供了理论与技术支持。

关键词：流动聚焦吹气式装置吸气式装置流体锥形液体射流主动激励

在线全文

学校读者我要写书评

暂无评论

新疆某金矿工艺矿物学研究

矿产综合利用 2018年第6期 95-97页

作者：牟凯青海交通职业技术学院青海西宁810000

利用显微镜观察、X-射线衍射分析、化学分析以及扫描电子显微镜对新疆某金矿进行了详细地工艺矿物学研究。研究表明,矿石中金的品位为1.20 g/t,金矿物主要为自然金,另有少量亮碲金矿、针碲金矿和碲金矿,微量碲金银矿。考虑到金矿物的嵌... 详细信息

利用显微镜观察、X-射线衍射分析、化学分析以及扫描电子显微镜对新疆某金矿进行了详细地工艺矿物学研究。研究表明,矿石中金的品位为1.20 g/t,金矿物主要为自然金,另有少量亮碲金矿、针碲金矿和碲金矿,微量碲金银矿。考虑到金矿物的嵌布粒度较细,均小于30μm,金矿物与黄铁矿等硫化物的嵌布关系不密切,并且金主要以裂隙金和粒间金的形式产出,因此建议该矿石采用氰化浸出工艺。

关键词：金矿工艺矿物学氰化浸出新疆

在线全文

学校读者我要写书评

暂无评论

蒙古某铁矿石工艺矿物学研究

金属矿山 2018年第10期47卷 110-114页

作者：牟凯青海交通职业技术学院青海西宁810000

中国国内铁矿资源不能满足市场需求,从蒙古进口了大量铁矿石。为实现该矿石的合理开发利用,采用化学分析、物相分析、XRD分析、扫描电子显微镜等检测手段对该矿石进行了系统的工艺矿物学研究。结果表明:矿石铁品位为45.53%,铜可综合回收... 详细信息

中国国内铁矿资源不能满足市场需求,从蒙古进口了大量铁矿石。为实现该矿石的合理开发利用,采用化学分析、物相分析、XRD分析、扫描电子显微镜等检测手段对该矿石进行了系统的工艺矿物学研究。结果表明:矿石铁品位为45.53%,铜可综合回收,杂质硫含量较高;矿石含铁矿物主要为磁铁矿,另有少量赤褐铁矿;其余金属矿物主要为黄铁矿,另有少量黄铜矿,微量铜蓝、蓝辉铜矿、磁黄铁矿及金红石等;矿石的构造主要为块状构造、浸染状构造,其次为网脉状、条纹状构造;矿石的结构主要有半自形—他形粒状结构、交代残余结构、假象结构、压碎结构、自形晶结构;磁铁矿多呈半自形—他形晶粒状及其集合体的形式分布在脉石矿物中,集合体中可见脉石矿物呈粒状或细脉状沿磁铁矿颗粒间隙分布,磁铁矿的嵌布粒度以中粒为主,在粗粒、中粒、细粒的分布率分别为32.43%、39.63%和27.03%;不同磨矿细度下磁铁矿的单体解离度统计结果表明,大部分磁铁矿在磨矿中易于单体解离,磁铁矿易于回收。针对矿石性质,提出采用粗磨磁选抛尾,粗精矿再磨除硫、硅等杂质的工艺流程进行选别。试验结果可以为该矿石的合理开发利用提供技术参考。

关键词：铁矿石嵌布特征解离度工艺矿物学

基于天地图API的综合服务管理系统设计与实现

在线全文

学校读者我要写书评

暂无评论

测绘通报 2016年第4期 114-116,132页

作者：穆凯新疆维吾尔自治区测绘科学研究院新疆乌鲁木齐830002 中亚地理信息开发利用国家测绘地理信息局工程技术研究中心新疆乌鲁木齐830002 新疆维吾尔自治区第二测绘院新疆乌鲁木齐830001

"访民情、惠民生、聚民心"是新疆地区为了便于走访民众,了解民生,更好地做好群众路线,以及处理一些社会应急处突事件的一项具体活动。本文针对该项活动开发了综合服务管理系统,具体介绍了如何应用天地图API结合Web GIS服务技术、数据库... 详细信息

"访民情、惠民生、聚民心"是新疆地区为了便于走访民众,了解民生,更好地做好群众路线,以及处理一些社会应急处突事件的一项具体活动。本文针对该项活动开发了综合服务管理系统,具体介绍了如何应用天地图API结合Web GIS服务技术、数据库技术来搭建活动综合服务管理系统平台,探讨了平台实现的技术路线与关键方法。使用天地图API搭建平台可以节约开发成本,缩短开发时间,带来高可靠、高性能、高质量和高效率的新系统,为实现新疆的稳定和长治久安提供技术保障和科学依据。

关键词：天地图API Web GIS 综合服务管理系统平台

Lattice-mismatch-induced formation of defect-rich Pd-Cu alloy nanocages for enhanced formic acid oxidation activity

在线全文

学校读者我要写书评

暂无评论

SCIENCE CHINA-CHEMISTRY 2025年第2期68卷 481-491页

作者： Liu, Zhaojun Wang, Zhengyan Wang, Zhaoyu Yuan, Hao Bai, Yuke Wang, Xiaoxiao mu, Zerui Wu, Chunxia Liu, kai Hu, Zhun Gao, Chuanbo Xi An Jiao Tong Univ Frontier Inst Sci & Technol Sate Key Lab Multiphase Flow Power Engn Xian 710049 Peoples R China Xi An Jiao Tong Univ Inst Ind Catalysis Sch Chem Engn & Technol Xian 710049 Peoples R China

Crystallographic defects in noble metal nanocrystals are recognized as highly active catalytic sites, significantly enhancing activities in many important reactions. Despite their importance, synthesizing noble metal nanocrystals with a high density of defects poses a considerable synthetic challenge. Here, we present a novel lattice mismatch-induced formation mechanism to create high-density defects in noble metal nanocrystals. This approach takes advantage of lattice mismatch to enable non-epitaxial nucleation and growth of a noble metal on a foreign metal substrate, forming abundant noble metal crystallites with random lattice orientations not dictated by the substrate lattice. As these crystallites grow extensively, they merge, forming numerous grain boundaries and yielding defect-rich noble metal nanocrystals. Defect-rich alloy nanocrystals can also be synthesized through a subsequent vacancy-diffusion alloying process. We take defective PdCu alloy nanocages as an example and demonstrate the effectiveness of crystallographic defects in enhancing catalytic performance of noble metal nanocrystals. The nanocages exhibit superior activity in the electrocatalytic formic acid oxidation reaction, which is 1.6 times greater than their defect-free counterparts. Our strategy offers a new avenue for creating defect-rich noble metal nanocrystals as highly efficient catalysts for a wide array of catalytic applications.

关键词： noble metal nanocrystals defects non-epitaxial growth electrocatalysis formic acid oxidation reaction