期刊文献+
共找到359篇文章
< 1 2 18 >
每页显示 20 50 100
早期美国报刊中的“Dean Lung”(丁龙)形象建构
1
作者 石坚平 《五邑大学学报(社会科学版)》 2023年第3期1-6,92,共7页
美国早期报刊在关于丁龙的相关报道中,先后为丁龙建构出了四种不同的人物形象:一个卑微的无足轻重的美国富翁家的华人男仆;一位神秘的东方哲人;一个美国公益慈善事业的捐赠者;一位受人敬重的仆人。这些“丁龙形象”的建构既被打上深深... 美国早期报刊在关于丁龙的相关报道中,先后为丁龙建构出了四种不同的人物形象:一个卑微的无足轻重的美国富翁家的华人男仆;一位神秘的东方哲人;一个美国公益慈善事业的捐赠者;一位受人敬重的仆人。这些“丁龙形象”的建构既被打上深深的时代烙印,又与早期报刊本身的媒体属性密切相关。这些要素应当成为今后学者利用美国早期报刊作为文献史料,深入开展丁龙研究的基础和前提。 展开更多
关键词 丁龙(deanLung) 卡朋蒂埃 形象建构 美国报刊
下载PDF
基于数据清洗“DEAN”流程的健康信息领域研究热点探测 被引量:18
2
作者 潘玮 郑鹏 +2 位作者 黄锦泉 牟冬梅 李茵 《现代情报》 CSSCI 2018年第10期73-77,共5页
[目的/意义]了解我国健康信息领域研究热点,提升研究热点识别的准确性。[方法/过程]论文首先构建了数据清洗"DEAN"流程,在此基础上以CNKI和万方数据库收录的2004-2017年健康信息领域文献数据为研究对象,运用CitespaceⅤ软件... [目的/意义]了解我国健康信息领域研究热点,提升研究热点识别的准确性。[方法/过程]论文首先构建了数据清洗"DEAN"流程,在此基础上以CNKI和万方数据库收录的2004-2017年健康信息领域文献数据为研究对象,运用CitespaceⅤ软件对健康信息领域的研究热点进行识别。[结果 /结论]研究共探测出我国健康信息领域六大研究热点,并对是否运用"DEAN"流程识别出的研究热点结果进行对比分析,发现运用"DEAN"流程能够提升研究热点识别的准确性。 展开更多
关键词 数据清洗 dean 健康信息 研究热点
下载PDF
Dean氟牙症指标与氟牙症牙面指数的比较 被引量:5
3
作者 司燕 张博学 +2 位作者 王鸿颍 林焕彩 高学军 《实用口腔医学杂志》 CAS CSCD 北大核心 2005年第4期519-522,共4页
目的:比较氟牙症患者Dean氟牙症指标(Deanindex,DI)与氟牙症牙面指数(toothsurfaceindexoffluorosis,TSIF)的特点及适用范围。方法:随机抽取河北省邢台高氟区12、15岁及35~44岁居民416名进行DI的调查,再从中随机抽取178名进行TSIF的调... 目的:比较氟牙症患者Dean氟牙症指标(Deanindex,DI)与氟牙症牙面指数(toothsurfaceindexoffluorosis,TSIF)的特点及适用范围。方法:随机抽取河北省邢台高氟区12、15岁及35~44岁居民416名进行DI的调查,再从中随机抽取178名进行TSIF的调查。调查前进行两指标的理论及临床培训。利用SPSS10.0统计软件及Excel数据库进行统计分析。结果:DI与TSIF的理论加权Kappa值较高,0.86~0.96,临床校准结果TSIF较低,且随涉及牙面的增加,可靠度降低,从“很好”到“中度”可靠。以DI为准的氟牙症患病率较TSIF结果低,两者差异在35~44岁年龄组中最明显,相差40%左右,这主要由于“可疑”一级不参与患病率的计算,此年龄组的可疑一级比例最高,为40.3%。结论:DI适于大型流行病学调查,并应结合社区氟牙症指数(communityfluorosisindex,CFI)使用;而TSIF更适于美观评价等专项调查研究,尤其对于重症氟牙症更敏感。 展开更多
关键词 氟牙症 流行病学指标 dean氏氟牙症指标 氟牙症牙面指数
下载PDF
膜分离过程中的Dean涡流及其作用分析 被引量:1
4
作者 吴景 杨志宏 +3 位作者 孟琴 张国亮 李娜 赖春芳 《膜科学与技术》 CAS CSCD 北大核心 2011年第1期118-124,共7页
综述了螺旋式膜组件的Dean二次流基本原理、管程常用传质关联式及其在膜分离过程中的应用状况,并从Dean二次流对膜过程通量和压力降以及传质性能的影响等诸方面.阐述了螺旋式组件的优势及限制因素.分析结果表明,流体在螺旋流道中由向心... 综述了螺旋式膜组件的Dean二次流基本原理、管程常用传质关联式及其在膜分离过程中的应用状况,并从Dean二次流对膜过程通量和压力降以及传质性能的影响等诸方面.阐述了螺旋式组件的优势及限制因素.分析结果表明,流体在螺旋流道中由向心力产生Dean流效应,使管内湍动状态增强、边界层效应减弱,从而缓解浓差极化,使管程传质和膜通量与直管组件相比有明显改善.此外,该结构还有助于消除壳程流体的沟流、死区等常见负面因素. 展开更多
关键词 螺旋式膜组件 dean涡流 传质 通量 压力降
下载PDF
氟斑牙的几种“Dean氏分类法”浅析 被引量:42
5
作者 王连方 《地方病通报》 2007年第1期71-73,共3页
关键词 氟斑牙 分类 dean氏分类法 综述
下载PDF
Dean涡的微粒分离原理在污水2级处理中的应用
6
作者 龙天渝 肖星 《水处理技术》 CAS CSCD 北大核心 2015年第7期65-67,71,共4页
将弯道层流流动形成的Dean涡产生的微粒分离原理运用于污水的2级处理,通过研发水动力分离处理装置,采用投加适量絮凝剂后的某河水进行实验,研究在流道中不同体积流量和絮凝剂含量下装置的分离效果。结果表明:当进水粒径在94.55~161.4μ... 将弯道层流流动形成的Dean涡产生的微粒分离原理运用于污水的2级处理,通过研发水动力分离处理装置,采用投加适量絮凝剂后的某河水进行实验,研究在流道中不同体积流量和絮凝剂含量下装置的分离效果。结果表明:当进水粒径在94.55~161.4μm时,分离效果最好;当体积流量小于600 m L/min时,体积流量越大则分离效果越高,而体积流量大于600 m L/min后,分离效果基本不变;在体积流量为600 m L/min时对浊度的去除率在90%以上,对TP和SS去除率分别在85%和50%以上,经装置分离后的清水的浊度大致为1 NTU;在体积流量为600 m L/min时,絮凝剂Fe Cl3的适宜投加质量浓度为21 mg/L。 展开更多
关键词 dean 水动力分离 粒径分布 体积流量 絮凝剂
原文传递
中空纤维膜渗透汽化过程中Dean涡强化传质的CFD模拟 被引量:2
7
作者 王洋 庄黎伟 +2 位作者 马晓华 许振良 王志 《化工学报》 EI CAS CSCD 北大核心 2018年第11期4655-4662,共8页
建立了一个三维的弯管式中空纤维膜渗透汽化传质CFD模型,研究Dean涡对渗透汽化过程传质的影响,描述了膜内侧的浓度和速率变化情况,该模型与Leveque传质关联式具有良好的一致性。研究结果显示:弯管膜中Dean涡的存在能降低边界层传质阻力... 建立了一个三维的弯管式中空纤维膜渗透汽化传质CFD模型,研究Dean涡对渗透汽化过程传质的影响,描述了膜内侧的浓度和速率变化情况,该模型与Leveque传质关联式具有良好的一致性。研究结果显示:弯管膜中Dean涡的存在能降低边界层传质阻力,总传质系数比直管膜提高了4倍;在不同的入口速率和浓度条件下,弯管膜内侧的壁面剪应力均大于直管膜。在膜阻力远小于边界层阻力的情况下,入口速率0.275 m·s^(-1),水浓度10%(质量)时,弯管膜的渗透通量为12636 g·m^(-2)·h^(-1),是直管膜的5倍。可见,弯管式中空纤维膜在渗透汽化过程中具有显著的强化传质效果。 展开更多
关键词 渗透汽化 传质强化 dean CFD
下载PDF
An Analysis of Dean Moriarty in On the Road——A True Hero in the 1950's America
8
作者 于贺 《海外英语》 2012年第23期206-207,210,共3页
This paper studies post-war America around the 1950's when On the Road was written and analyzes the protagonist Dean Moriarty as a spokesman of the Beat Generation.He is a typical beat who revolts against the trad... This paper studies post-war America around the 1950's when On the Road was written and analyzes the protagonist Dean Moriarty as a spokesman of the Beat Generation.He is a typical beat who revolts against the traditional social values and chases after the spiritual complacency.In addition,he opposes wars and advocates the equality between men and women.Thus in a sense Dean is a rebellious hero and stands ahead of his age. 展开更多
关键词 post-war AMERICA dean Moriary the BEAT Generation
下载PDF
Dean模型在山东半岛西北岸滩动力地貌研究的应用 被引量:1
9
作者 刘成 胡日军 +2 位作者 朱龙海 林纪江 张卓 《海洋科学进展》 CAS CSCD 北大核心 2020年第2期348-358,共11页
根据山东半岛西北部25条实测岸滩剖面及相关表层沉积物、波浪、潮流资料,通过计算浪潮作用指数K和波浪-沉积物参数Ω,确定研究区主控动力因素并对海滩动力地貌类型进行划分,在此基础上应用Dean平衡剖面模型对实测剖面进行拟合,探讨了该... 根据山东半岛西北部25条实测岸滩剖面及相关表层沉积物、波浪、潮流资料,通过计算浪潮作用指数K和波浪-沉积物参数Ω,确定研究区主控动力因素并对海滩动力地貌类型进行划分,在此基础上应用Dean平衡剖面模型对实测剖面进行拟合,探讨了该模型的适用性及其参数物理意义等问题。山东半岛西北部整体为浪控海岸,刁龙嘴-三山岛岸段、海北嘴-石虎嘴岸段和三山岛-海北嘴岸段均属过渡型海滩,屺坶岛-栾家口岸段属消散型海滩。研究区实测剖面与Dean模型的拟合结果整体较好,部分剖面(剖面1、剖面2、剖面3、剖面5、剖面8)由于发育离岸沙坝,使其形态与Dean模型预测的平滑上凹的形态特点存在一定差别。屺坶岛-栾家口岸段(剖面19~剖面24)受外海侧桑岛及沿岸龙口人工岛群影响,与Dean模型预测结果存在较大差别,Dean模型对发育槽-坝体系的海滩的拟合仍具有局限性。Dean模型中m和A分别反映了海滩剖面反射性和泥沙沉速,与海滩动力地貌类型判别公式计算结果吻合较好。 展开更多
关键词 山东半岛西北部 动力地貌类型 dean模型 平衡剖面
下载PDF
超滤膜法制备乳化柴油过程中Dean旋流效应的影响 被引量:1
10
作者 张春芳 刘建 +2 位作者 白云翔 顾瑾 孙余凭 《化工进展》 EI CAS CSCD 北大核心 2011年第10期2141-2146,共6页
根据Dean旋流原理,采用螺旋形中空纤维超滤膜制备乳化柴油,考察了螺旋形膜组件的螺距和螺径对乳化效果的影响,研究了Dean旋流效应对强化膜面剪切力、提高乳液品质、降低膜面污染等方面的作用。结果表明:螺径和螺距减小时,膜面剪切力增大... 根据Dean旋流原理,采用螺旋形中空纤维超滤膜制备乳化柴油,考察了螺旋形膜组件的螺距和螺径对乳化效果的影响,研究了Dean旋流效应对强化膜面剪切力、提高乳液品质、降低膜面污染等方面的作用。结果表明:螺径和螺距减小时,膜面剪切力增大,膜内的Dean旋流程度加剧,乳液液滴直径减小,但过小的螺径使液滴分散系数增加,不利于制备性能优异的乳液;同时,螺径和螺距的减小可以提高膜通量保留率,有效抑制膜面污染层的形成;与直形膜相比,螺旋形膜可显著降低乳化剂用量,其通量保留率达到直形膜的3.5倍。 展开更多
关键词 dean旋流 超滤膜 乳化柴油
下载PDF
Circle of Willis atherosclerosis, Alzheimer's disease and the Dean number
11
作者 Rovshan M Ismailov 《World Journal of Cardiology》 CAS 2013年第10期394-396,共3页
The important role of atherosclerosis in pathophysiology of Alzheimer's Disease has become evident.Mechanisms such as hyperlipidemia,inflammation,abdominal obesity and insulin resistance are important yet they may... The important role of atherosclerosis in pathophysiology of Alzheimer's Disease has become evident.Mechanisms such as hyperlipidemia,inflammation,abdominal obesity and insulin resistance are important yet they may not fully explain the specific involvement of the Circle of Willis in these pathologies.The Circle of Wills is a complex geometrical structure which has several areas with different curvature as well as various branching angles of vessels composing the circle.The hemodynamics in this region should take into account the Dean number which indicates the influence of curvature on the resistance to blood flow.Thus,areas with various curvature and angles may have different hemodynamics and there are certain areas in the Circle of Willis that are more likely to develop atherosclerotic changes.Therefore,this could suggest the novel pathophysiological pathway resulting from the geometric peculiarities of the Circle of Willis.One of the directions of future research is to examine whether specific areas of the Circle of Willis are more likely to develop atherosclerotic changes compared to other ones.Selective areas of the Circle of Willis affected by atherosclerotic changes could indicate the primary role of atherosclerosis promoting Alzheimer's disease although other pathophysiological mechanisms suggesting the opposite direction should be also examined in prospective studies. 展开更多
关键词 Circle of WILLIS Alzheimer’s DISEASE ATHEROSCLEROSIS MECHANISM The dean NUMBER
下载PDF
反垃圾邮件何时才既叫好又叫座?——访博威特公司全球CEO Dean Drako
12
作者 宗文 《网管员世界》 2004年第12期22-22,共1页
勿庸置疑,反垃圾邮件市场是2004年国内IT市场,尤其是安全市场中的一个“热门”,虽然从市场数字来讲,全球几亿美元的市场确定了反垃圾邮件在IT的大舞台上现在只能是“配角”。从去年底趋势科技公司推出反垃圾邮件解决方案,今年初赛... 勿庸置疑,反垃圾邮件市场是2004年国内IT市场,尤其是安全市场中的一个“热门”,虽然从市场数字来讲,全球几亿美元的市场确定了反垃圾邮件在IT的大舞台上现在只能是“配角”。从去年底趋势科技公司推出反垃圾邮件解决方案,今年初赛门铁克3.7亿元并购Bightmail公司以及各个杀毒软件公司强力宣传自己产品的反垃圾邮件特性,国内垃圾邮件市场倒也热热闹闹. 展开更多
关键词 电子邮件 反垃圾邮件 CEO dean Drako 博威特公司
下载PDF
螺旋形中空纤维超滤膜处理高浓度废水时Dean旋流对膜污染阻力的削弱作用
13
作者 孙余凭 霍彦强 顾瑾 《膜科学与技术》 CAS CSCD 北大核心 2009年第3期27-32,共6页
根据Dean旋流原理,以洗毛废水为高浓度废水,用螺旋形中空纤维超滤膜研究透膜压差、膜面流速、料液浓度、Dean参数等对膜污染阻力的影响.结果表明:在50℃,透膜压差△P为80kPa,膜面流速V为0.68m/s,螺距b为5mm,螺径dc为25mm,处... 根据Dean旋流原理,以洗毛废水为高浓度废水,用螺旋形中空纤维超滤膜研究透膜压差、膜面流速、料液浓度、Dean参数等对膜污染阻力的影响.结果表明:在50℃,透膜压差△P为80kPa,膜面流速V为0.68m/s,螺距b为5mm,螺径dc为25mm,处理水质为CODcr46365mg/L、羊毛脂12g/L、pH=8.0、总固体浓度20158mg/L时,螺旋形膜透过液通量J是直形膜的1.6~1.96倍,阻力Rf比直形膜降低60%以上.在Dean参数的构成中,提高试验温度和减小螺距对膜污染阻力的削弱效果最为显著. 展开更多
关键词 螺旋形膜 dean旋流 高浓度废水 膜污染阻力
下载PDF
On the Bifurcations of Dean Flow between Porous Horizontal Cylinders with a Radial Flow and a Radial Temperature Gradient
14
作者 Luiza Shapakidze 《Journal of Applied Mathematics and Physics》 2017年第9期1725-1738,共14页
The stability of a heat-conducting flow due to the pumping of a fluid around the annulus of horizontal porous cylinders is studied. The basic flow is under the action of radial flow and a radial temperature gradient. ... The stability of a heat-conducting flow due to the pumping of a fluid around the annulus of horizontal porous cylinders is studied. The basic flow is under the action of radial flow and a radial temperature gradient. The objects of investigations are different regimes and bifurcations which may arise in this flow. 展开更多
关键词 dean FLOW POROUS Cylinders TRANSITIONS INSTABILITY BIFURCATIONS
下载PDF
Moral Education, Legal Practice——Exclusive Interview with Lu Jianping, Dean of BNU Law School
15
作者 Liu Xinwei 《China's Foreign Trade》 2019年第3期28-31,共4页
BNU Law School is one of the youngest and most dynamic faculties at Beijing Normal University.Its precursor was the Law major established by the Department of Philosophy in 1995,the Department of Law established in 20... BNU Law School is one of the youngest and most dynamic faculties at Beijing Normal University.Its precursor was the Law major established by the Department of Philosophy in 1995,the Department of Law established in 2002,and the Criminal Law Science Research Institute was established in 2005.It culminated in the formal establishment of BNU Law School in 2006.Although BNU Law School was established in recent time,it has made outstanding achievements in various fields. 展开更多
关键词 dean of BNU Law School EXCLUSIVE INTERVIEW with Lu Jianping LEGAL Practice MORAL Education
下载PDF
Mature While Growing up, Innovative While Inheriting——Exclusive Interview with Zhao Xinli, the Associate Dean of the Advertising School of Communication University of China
16
作者 Liu Xinwei 《China's Foreign Trade》 2019年第3期24-27,共4页
As the Chinese proverb goes,a man of his thirties should be independent.For a person,it s time to shoulder the responsibility he or she longs for.For a major and a School,it s time to root deep,to take responsibility ... As the Chinese proverb goes,a man of his thirties should be independent.For a person,it s time to shoulder the responsibility he or she longs for.For a major and a School,it s time to root deep,to take responsibility and to fulfill its dream of 'a School stands for a hundred years as a tree for a thousand years'.As the Advertising School of Communication University of China embraces its 30th 'birthday',Zhao Xinli,the Associate Dean of the School,was exclusively interviewed by China’s Foreign Trade. 展开更多
关键词 the ASSOCIATE dean of the ADVERTISING School of Communication University of China China Innovative WHILE Inheriting MATURE WHILE Growing up EXCLUSIVE Interview with ZHAO Xinli
下载PDF
Cultivate Talents with Both Noble Qualities and Knowledge of Chinese and Western Culture——Exclusive Interview with Professor Yin Meiqun, Dean of the Business School of Beijing International Studies University
17
作者 Wang Lili 《China's Foreign Trade》 2019年第2期28-31,共4页
Although it was frigid outside mid-winter, classrooms in the Business School of Beijing International Studies University are still as warm as spring,because of the passionate teachers and students. Professors were con... Although it was frigid outside mid-winter, classrooms in the Business School of Beijing International Studies University are still as warm as spring,because of the passionate teachers and students. Professors were conducting lectures in English, as the students listen carefully and occasionally answered the questions posed in fluent English.If hearing their voices only, audiences might easily mistake that they were in a university in an English-speaking country.' 展开更多
关键词 School In dean of the Business School of Beijing International Studies University EXCLUSIVE INTERVIEW with PROFESSOR YIN Meiqun Cultivate Talents with BOTH NOBLE Qualities and Knowledge of Chinese and Western Culture
下载PDF
基于Dean涡效应的弯管冲蚀机理分析
18
作者 吕文超 陈培红 徐亮 《江苏航运职业技术学院学报》 2022年第1期53-58,共6页
冲刷腐蚀是船舶管路损伤失效的重要原因,而管道内介质的流动速度是影响冲刷腐蚀速率的关键因素。基于数值模拟方法,对90°弯管不同位置的液相介质速度分量进行了计算与分析,发现管道冲刷腐蚀速率并非由介质流动合速度决定,而是由与... 冲刷腐蚀是船舶管路损伤失效的重要原因,而管道内介质的流动速度是影响冲刷腐蚀速率的关键因素。基于数值模拟方法,对90°弯管不同位置的液相介质速度分量进行了计算与分析,发现管道冲刷腐蚀速率并非由介质流动合速度决定,而是由与管道轴向垂直的横截面内的速度分量(Dean涡强度)决定。横截面内的Dean涡强度越大,介质与壁面金属基材之间的传质过程越快,越容易导致管道冲刷腐蚀加速。 展开更多
关键词 冲刷腐蚀 弯管 dean 数值计算
下载PDF
A Micromixer Using the Taylor-Dean Flow: Effect of Inflow Conditions on the Mixing
19
作者 Toshihiko Kawabe Yasutaka Hayamizu +4 位作者 Shinichiro Yanase Takeshi Gonda Shinichi Morita Shigeru Ohtsuka Kyoji Yamamoto 《Open Journal of Fluid Dynamics》 2014年第5期463-471,共9页
Chaotic mixing in a curved-square channel flow is studied experimentally and numerically. Two walls of the channel (inner and top walls) rotate around the center of curvature and a pressure gradient is imposed in the ... Chaotic mixing in a curved-square channel flow is studied experimentally and numerically. Two walls of the channel (inner and top walls) rotate around the center of curvature and a pressure gradient is imposed in the direction toward the exit of the channel. This flow is a kind of Taylor-Dean flows. There are two parameters dominating the flow, the Dean number De (∝ the pressure gradient or the Reynolds number) and the Taylor number Tr (∝ the angular velocity of the wall rotation). In the present paper, we analyze the physical mechanism of chaotic mixing in the Taylor-Dean flow by comparing experimental and numerical results. We produced a micromixer model of the curved channel several centimeters long with square cross section of a few millimeters side. The secondary flow was measured using laser induced fluorescence (LIF) method to examine secondary flow characteristics. We also performed three-dimensional numerical simulations for the exactly same configuration as the experimental system to study the mechanism of chaotic mixing. It is found that good mixing performance is achieved for the case of De ≤ 0.1Tr, and that mixing efficiency changes according to the difference in inflow conditions. The flow is studied both experimentally and numerically, and both results agree with each other very well. 展开更多
关键词 Taylor-dean FLOW CHAOTIC MIXING Secondary FLOW LIF CFD
下载PDF
A Micromixer Using the Taylor-Dean Flow: Effects of Aspect Ratio and Inflow Condition on the Mixing
20
作者 Yasutaka Hayamizu Toshihiko Kawabe +4 位作者 Shinichiro Yanase Takeshi Gonda Shinichi Morita Shigeru Ohtsuka Kyoji Yamamoto 《Open Journal of Fluid Dynamics》 2015年第3期256-264,共9页
Chaotic mixing in three different types of curved-rectangular channels flow has been studied experimentally and numerically. Two walls of the channel (inner and top walls) rotate around the center of curvature and a p... Chaotic mixing in three different types of curved-rectangular channels flow has been studied experimentally and numerically. Two walls of the channel (inner and top walls) rotate around the center of curvature and a pressure gradient are imposed in the direction toward the exit of the channel. This flow is a kind of Taylor-Dean flow. There are two parameters dominating the flow, the Dean number De (∝ the pressure gradient or the Reynolds number) and the Taylor number Tr (∝ the angular velocity of the wall rotation). In this paper, we analyze the physical mechanism of chaotic mixing in the Taylor-Dean flow by comparing experimental results and numerical ones. We produced three micromixer models of the curved channel, several centimeters long, with rectangular cross-section of a few millimeters side. The secondary flow is measured using laser induced fluorescence (LIF) method to examine secondary flow characteristics. Also we performed three-dimensional numerical simulations with the open source CFD solver, OpenFOAM, for the same configuration as the experimental system to study the mechanism of chaotic mixing. It is found that good mixing performance is obtained in the case of De ≤ 0.1 Tr, and it becomes more remarkable when the aspect ratio tends to large. And it is found that the mixing efficiency changes according to the aspect ratio and inflow condition. 展开更多
关键词 Component Taylor-dean FLOW CHAOTIC MIXING Secondary FLOW LIF CFD
下载PDF
上一页 1 2 18 下一页 到第
使用帮助 返回顶部