Micromixing efficiency is an important parameter for evaluating the multiphase mass transfer performance and reaction efficiency of microreactors.In this work,the novel curved capillary reactor with different shapes w...Micromixing efficiency is an important parameter for evaluating the multiphase mass transfer performance and reaction efficiency of microreactors.In this work,the novel curved capillary reactor with different shapes was designed to generate Dean flow,which was used to enhance the liquid-liquid micromixing performance.The Villermaux-Dushman probe reaction was employed to characterize the micromixing performance in different curved capillary microreactors.The effects of experiment parameters such as liquid flow rate,inner diameter,tube length,and curve diameter on micromixing performance were systematically investigated.Under the optimal conditions,the minimum value of the segmentation factor XS was 0.008.It was worth noting that at the low Reynolds number(Re<30),the change of curved shape on the capillary microreactor can significantly improve the micromixing performance with XS reduced by 37.5%.Further,the correlations of segment index XS with dimensionless factor such as Reynolds number or Dean number were developed,which can be used to predict the liquid-liquid micromixing performance in capillary microreactors.展开更多
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
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
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
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
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
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
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
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
基金supports of National Natural Science Foundation of China(22308057)Outstanding Talent Introduction Funds from Fuzhou University(0040-511175)Fuzhou University Testing Fund of precious apparatus(2023T003).
文摘Micromixing efficiency is an important parameter for evaluating the multiphase mass transfer performance and reaction efficiency of microreactors.In this work,the novel curved capillary reactor with different shapes was designed to generate Dean flow,which was used to enhance the liquid-liquid micromixing performance.The Villermaux-Dushman probe reaction was employed to characterize the micromixing performance in different curved capillary microreactors.The effects of experiment parameters such as liquid flow rate,inner diameter,tube length,and curve diameter on micromixing performance were systematically investigated.Under the optimal conditions,the minimum value of the segmentation factor XS was 0.008.It was worth noting that at the low Reynolds number(Re<30),the change of curved shape on the capillary microreactor can significantly improve the micromixing performance with XS reduced by 37.5%.Further,the correlations of segment index XS with dimensionless factor such as Reynolds number or Dean number were developed,which can be used to predict the liquid-liquid micromixing performance in capillary microreactors.
文摘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。
文摘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.
文摘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.
文摘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.
文摘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.
文摘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.
文摘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.'
文摘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.
