145 research outputs found
A Mysterious Woman in A Dream of Red Mansions: Qin Keqing
No full textWritten in the mid-eighteenth century during the reign of Emperor Qianlong of the Qing Dynasty, A Dream of Red Mansions is regarded as one of the greatest Chinese classical novels. It has been popular throughout the last two hundred years and more. The whole work through which is full of mysteries not only about the book, but also about the author. Among many characters in A Dream of Red Mansions, Qin Keqing is the most mysterious. Some researchers claimed that she was the key to all the mysteries in A Dream of Red Mansions and the huge secret hidden behind the book are attached to her. This article tries to explore and analyze these mysteries about Qin Keqing, revealing the great mysteries hidden in the book
Supplementary_Material_a_clean_copy - Influence of More Than 5 Years of Continuous Exposure to Antipsychotics on Cerebral Functional Connectivity of Chronic Schizophrenia
No full textSupplementary_Material_a_clean_copy for Influence of More Than 5 Years of Continuous Exposure to Antipsychotics on Cerebral Functional Connectivity of Chronic Schizophrenia by Qi Miao, Chengcheng Pu, Zhijiang Wang, Chao-Gan Yan, Chuan Shi, Qingjiu Cao, Xijin Wang, Zhang Cheng, Xue Han, Lei Yang, Yunyao Lai, Yanbo Yuan, Hong Ma, Keqing Li, Nan Hong and Xin Yu in The Canadian Journal of Psychiatry</p
Ruili-Bonade dui liu ji shi qi dui liu de shi yan yan jiu
No full textPh.D.本論文包含了倆部分。第一部分研究主要集中在傳統瑞利－伯纳德對流, 第二部分研究集中在多相瑞利－伯纳德對流（濕氣對流）。在論文的第一部分，我們主要研究了傳統瑞利－伯纳德對流中倆個重要的問題：羽流效應和聚合物效應。在靠近下底板和側壁的區域裡，羽流佔據統治地位，浮力效應非常明顯，因此，通过應用拉格朗日粒子追蹤方法我们研究了流體的加速度統計特性，能量耗散和能量級串。由於羽流的存在，在相同的Ra條件下，這些區域測得的加速度明顯高於幾乎沒有羽流的中央區域。另一個重要的發現是在Ra適當的範圍內，加速度方差的標度率符合浮力項所期望的數值，而不符合被廣泛期待的Heisenberg-Yaglom關係。另外，能量耗散和Ra的的標度率介於Grossmann-Lohse理論所預測的中央值和邊界值之間，這個結果側面說明：由於羽流的存在，在我們所測量的下底板和側壁區域里，中央和邊界區域對能量耗散都有貢獻。同時，在適當範圍的Ra條件下，我們觀測到慣性區間的歐拉二階結構方程的標度率為4/5，比在中央區域成立的K41理論推導的2/3大，但是比完全由浮力驅動的流體中所認為的BO59理論6/5小，這一結果說明羽流在這個區域佔據主導地位，但是也可以看到對流背景對結果的影響。另外，在一個底板和上板都有金字塔尖凸起的對流槽的中央部位，我們也觀察到了羽流效應，能量耗散的標度率與我們之前在靠近底板和側壁觀測到的結果十分吻合。聚合物效應的實驗中，熱對流中加入倆種不同的聚合物。不同的Ra條件下，在靠近底板和側壁的區域，我們研究了加速度統計和能量耗散特性。隨著聚合物濃度的增加，在這倆個測量區域中，加速度和能量耗散都有明顯的減小，靠近底板區域的數值減少得更快。在濃度達到飽和值時，能量耗散率最小值出現，數值約為濃度為零時的20%。在本論文的第二部分，我們系統的研究了濕氣對流的熱輸運和速度場特性。濕氣對流的傳熱效率隨著對流中央溫度的升高而增加，約為干空氣傳輸效率的3-4倍。Nu和Ra的標度率為0.45，大於傳統的瑞利－伯纳德對流標度率。應用粒子成像測速方法，我們得到了準二維方形對流槽中的速度場，隨著中央溫度的增加，流場隨之增強，表現在平均速度大幅增加。在粒子追蹤速度測量方法中，我們獲得了濕氣對流中的加速度，在相同Ra條件下，約為傳統熱對對流（以水作為對流流體）中加速度的10倍。This thesis contains two parts, Part I is mainly focused on traditional turbulent Rayleigh-Bénard (RB) convection, and Part II is on multi-phase RB convection.In the first Part, we study two important issues: the plume effect and the polymer effect. The acceleration statistics, the energy dissipation rate, and the energy cascade are measured by the Lagrangian particle tracking velocimetry (PTV) in the regions near the cell sidewall and bottom plate, where plumes play a key role and buoyancy effects are dominant. Because of the plumes, the accelerations are higher than that measured in the homogeneous and isotropic region at same Ra. Most importantly, at small Ra range, the power law scaling of acceleration variance as a function of Ra agrees well with the buoyancy terms, and the Heisenberg-Yaglom relation does not hold in these regions. The Ra-dependency of measured kinetic energy dissipation rate ϵ_u in these regions do not agree well with the Grossmann-Lohse model, and the corresponding scaling exponent is between those for the bulk and the boundary layer. The scaling exponent of the structure functions (SFs) in the inertial range is 4/5 at moderate Ra, and is higher than 2/3 predicted by the K41 theory, which is expected in bulk region with no plume effect, and smaller than 6/5 of the BO59 theory, which is expected in buoyancy driven flows. The plume effects were also observed in the center region in a convection cell with rough plates, where plumes become more coherent and occupy the entire system. The scaling of ϵ_u with Ra in this case agrees well with those in the sidewall region and bottom region in smooth cells.Two kinds of polymers, polyacrylimid (PAM) and polyethylene (PEO), are added to the convecting fluids to study the polymer effect in turbulent RB convection. Different regions of the convection cell and polymer concentrations are investigated, and the acceleration statistic and energy transfer are obtained. For these two different polymer additives, similar effects are observed. A significant decrease of the acceleration variance is observed both in the bulk and bottom region as the concentration of polymer is increased, and it decreases more quickly in the bottom region than that of the bulk region. The shape of normalized acceleration probability density function remained unchanged. The ratio of horizontal component and vertical component of acceleration variance keep unchanged at the bulk region compared, which increased with the polymers concentration at the bottom region. The energy dissipation rate in the dissipative range is found to have decreased to about 20% of that for pure water at the same Ra, for PAM and PEO concentrations of 18 ppm and 180 ppm, respectively.In the second Part, the heat transport and flow field properties of moist turbulent RB convection is investigated systematically. Heat transport in moist RB convection is studied with varying Rayleigh number Ra and for different bulk temperature (Tbulk). It is found that the heat transfer efficiency of moist convection increases monotonously with bulk temperature and is several times higher than that in the air. The Nu-Ra scaling is about 0.45, larger than that of traditional RB convection. A possible explanation is that the evaporation of water at the bottom plate, like the hot plumes, will enhance the large-scale circulation and help vapor to condense into droplets, therefore enhance the heat transfer efficiency. Droplets that condense from the vapor are observed optically. The entire flow field of the moist RB convection was measured by particle image velocimetry in a quasi-2D rectangular cell, where droplets were used as the tracking particles. As bulk temperature increases, the velocity increases and the large-scale circulation becomes stronger, it is almost 10 times of that in traditional RB convection using water as working fluid. The particle tracking velocimetry (PTV) result shows that droplet density increases significantly with increasing bulk temperature. The acceleration is also found to be much larger than that of RB convection using water as the working fluid.Li, Xiaoming = 瑞利-伯纳德對流及濕氣對流的實驗研究 / 李小明.Thesis Ph.D. Chinese University of Hong Kong 2017.Includes bibliographical references (leaves 71-87).Abstracts also in Chinese.Title from PDF title page (viewed on 24, October, 2019).Li, Xiaoming = Ruili-Bonade dui liu ji shi qi dui liu de shi yan yan jiu / Li Xiaoming.Detailed summary in vernacular field only.Detailed summary in vernacular field only.Detailed summary in vernacular field only.Detailed summary in vernacular field only
Ruili-Bonade dui liu ji shui ping dui liu de shi yan yan jiu
No full text本論文由兩部分組成。第一部分介紹了關於瑞利－伯纳德對流的兩項工作。第一項工作在五個側向寬高比不同的矩形對流槽中研究了空間約束效應對流體動力學和傳熱效率的影響。實驗發現，整體流場隨著約束強度的增加而明顯減弱，而且大尺度環流的流向反轉變得更為頻繁。令人驚訝的是，儘管流動變慢，總體傳熱效率卻顯著地提高。仔細分析表明，空間約束改變了邊界層中羽流的形態和動力學特性，表現為形成的羽流結構更為有序和充滿活力，從而導致邊界層變得更薄更均勻，傳熱效率由此得以提高。第二項工作研究了不同溫度邊界條件對湍流熱對流的影響。實驗在兩個對流槽中進行：其中一個在上邊界固定溫度而在下邊界固定熱通量（HC 對流槽），另一個則在兩個邊界都保持恆定溫度（CC對流槽）。研究發現，在恆定溫度的邊界條件下，溫度邊界層的厚度對瑞利數的依賴關係滿足于1/3的標度律，區別于在恆定熱通量下的行為（標度律近似為2/7）。此外，CC 對流槽中的流場強度平均比HC對流槽中的要強∼9% ，其流向反轉頻率也要快1.5倍。我們把這些現象歸咎於不同溫度邊界條件下羽流的發射強度不同。論文的第二部分對另外一種重要的熱對流系統，水平對流，進行了實驗研究。在加熱和冷卻位于系統上邊界同一高度的條件下，我們觀測到了一個貫穿整個對流槽的大尺度環流。通過染料示蹤表明，流場中的迴流并不一定需要損耗能量來跨越溫度邊界層，因此可以更有效地維持其流動強度。對於熱傳輸效率以及溫度邊界層厚度隨瑞利數的變化關係，實驗觀測到了一個0.3的標度律，不同于經常被報道的理論值（0.2），這可能是因為在高瑞利數下流動狀態發生了轉變。本研究的结果表明，表面温度梯度不仅可以驱动大尺度环流，而且其強度也比人们普遍认为的要强。This thesis consists of two self-contained parts, both related to the topic of thermal convection.In the first part, two sets of studies on turbulent Rayleigh-Bénard convection are presented.The first study addresses the confinement effects on the heat transport and flow dynamics in quasi-2D geometry. The experiments were conducted in five rectangular cells with the same height and length, while the width being varied to produce a lateral aspect ratio Γ ranging from 0.6 to 0.1. As expected, with decreasing Γ, i.e. increasing the level of confinement, the overall flow slows down and more plumes travel through the bulk region, thus resulting in a large-scale circulation with more frequent reversals. Surprisingly, despite a slower flow, the global heat transport efficiency enhances significantly. Detailed examinations from experiment and simulation show that this enhancement is brought about by the changes in the dynamics and morphology of the thermal plumes in the boundary layers: the confined geometry produces more coherent and energetic plume clusters that in turn result in more uniform and thinner thermal boundary layers. This study demonstrates how changes in turbulent bulk flow can influence the boundary layer dynamics and shows that the quasi-2D geometry is very different from the true 2D and also the 3D systems.The second study investigates the influence of thermal boundary conditions. Two experimentally achievable configurations are examined; one is fixed-flux at the bottom boundary and fixed-temperature at the top (HC cell), while the other is fixed-temperature at both boundaries (CC cell). It is found that, rather surprisingly, the Rayleigh number dependence of the thermal boundary layer thickness follows a 1/3 power law approximately under the condition of constant temperature, in contrast to the behavior in the case of constant flux (close to a 2/7 scaling). It is further found that the flow strength is on average ∼ 9% larger in the CC cell, and its flow reversal frequency is ∼ 1.5 faster than that for the HC case, which may be understood as changes in the plume emission dynamics.The second part deals with horizontal convection. The experiment was conducted with a long apparatus (∼ 2.4 m) with the heating and cooling imposed over the top boundary. Flow visualization studies revealed a full penetrating circulation and suggest that the returning flow does not necessarily overcome the stratification to penetrate the entire thermal BL, in such a way that it can “save its kinematic energy thus supports the motion more efficiently. Both the heat transport efficiency and thermal BL thicknesses are found to follow a 0.3 power law, in contrast to the often-reported value of 0.2. This is likely caused by a flow-regime transition in the high Ra number range. This study demonstrates experimentally that a surface temperature gradient is capable of driving a large-scale circulation and its strength is much stronger than what is generally believed by the oceanography community.Detailed summary in vernacular field only.Detailed summary in vernacular field only.Huang, Shidi = 瑞利-伯納德對流及水平對流的實驗研究 / 黃仕迪.Thesis (Ph.D.) Chinese University of Hong Kong, 2013.Includes bibliographical references (leaves 97-110).Abstracts also in Chinese.Huang, Shidi = Ruili-Bonade dui liu ji shui ping dui liu de shi yan yan jiu / Huang Shidi
Xuan zhuan Ruili-Bonade dui liu he shui ping dui liu de shi yan yan jiu
No full textPh.D.Two kinds of thermal convection are studied in this thesis, i.e., the rotating Rayleigh-Bénard convection (RRBC) and the horizontal convection (HC).The effects of symmetrically distributed centrifugal force in RRBC are studied in different parameter spaces. This is achieved by pushing the rotation speed +Ω to very high values. The measured enhanced bulk temperature and the decreased sidewall temperature imply that the centrifugal force indeed takes effect at these fast speeds. Compared to previous studies, the different behaviors of the heat transport efficiency, the first Fourier mode energy, the global temperature gradient at sidewall and the gradient at bulk all show the influence of centrifugal force. The centrifugal force is usually neglected in RRBC. The present studies indicate that the centrifugal force must be taken into consideration to better explore the RRBC system in a wider parameter space. Also our experimental results clearly show that the centrifugal force sets in much earlier than recently predicted. We also study the case of reversing the rotation direction −Ω in RRBC. The rotation axis of +Ω is anti-parallel to the gravity while these two are parallel in the −Ω case. Compared to the +Ω case, the heat transport efficiency is larger and the sidewall and bulk temperatures are colder. These differences suggest more attention about this issue are needed when studying RRBC. Also this may help understanding the different flow behaviors in the north and south poles of a planet.A novel experiment is designed to investigate the asymmetrically distributed centrifugal force in RRBC. This directed centrifugal force is applied by shifting the convection cell away from the rotation axis by a distance d. The symmetry breaking results in dramatic changes of flow fields. The flow visualization and the azimuthal temperature profiles show that the hot and cold fluids are separated and accumulated at two opposite positions. Compared to the conventional RRBC (i.e., d = 0 mm), the heat transport efficiency in the off-centered case shows a sharp enhancement, which is followed by an optimal state (a maximum value). The energy of the first Fourier mode indicates that the enhancement of heat transport is caused by the changes of flow dynamics. Two competing separation effects are identified to understand this optimal state, i.e., the positive effects of increased coherence and the negative effects of decreased coherent size. Note that this asymmetrical centrifugal force is added to the symmetrical one. A more detailed examination of the data shows an asymmetric effect of the total centrifugal force on hot and cold coherent structures. This is because the symmetrically distributed centrifugal force competes with the directed one for hot fluid, while for cold fluid, these two work together. The resemblance of the directed centrifugal force to the tidal force suggests some potential applications in astrophysics.The last part deals with the horizontal convection (HC). Like the situations in ocean circulations, the heating and cooling are imposed at the same horizontal level in HC. The flow visualization and the temperature profiles reveal that there is a strongly stratified thermal boundary layer near the upper surface and the bulk is weakly stratified. The flow field can be divided into three regions. The power spectrum densities and fluctuations of temperature signals show that the flow in the unstably stratified cold region is very turbulent while in the stably stratified hot region it is extremely weak and laminar. The situations in the free-surface region are in the middle of the cold and hot regions. The heat transport shows a transition from the classical 0.2 Rossby scaling to a 0.3 scaling. The heat transport is limited by the conduction in the hot region. It is found that when the driving force in the cold region is strong enough, the hot region can also be influenced by the driven flow, which may result in the above-mentioned transition. Also this indicates that in real ocean circulations, the strong mixing due to the wind at low latitude (hot region) is more important than that at high latitude (cold region), since the mixing can compensate the limitation at low latitude.本論文研究了兩類熱對流，即旋轉瑞利-伯纳德對流(RRBC) 和水平對流(HC)︒第一個實驗研究了在不同參數空間下，對稱分佈的離心力在RRBC 系統中的作用︒在實驗中我們通過增加轉速+Ω 來得到較大的離心力︒測量到的流場中心溫度的增加和側壁溫度的降低都表明在快轉速下離心力確實起了作用︒和之前的研究結果相比，傳熱效率︑第一階傅立葉模的能量︑在側壁上測得的溫度梯度以及流場中心的溫度梯度都由於受離心力的影響而表現出不同的行為︒在以往RRBC 的研究中，離心力通常被忽略︒本研究表明，如果想在更大的參數空間裡進一步研究RRBC，離心力必須得考慮進去︒另外，我們的結果表明在RRBC 系統中相比於最近的預測結果，離心力更早起作用︒我們還研究了反轉（−Ω）的情況︒正轉（+Ω）時，轉軸方向和重力方向是反平行的；而反轉（−Ω）時這兩者是平行的︒我們發現相比於正轉，反轉下的傳熱效率更大而且側壁和中心溫度都更低︒這些差異表明，在研究RRBC 時需要注意正反轉的問題︒另外，這些結果可能有助於理解一個星球上南北極兩端不同的流場行為︒我們設計了一個新的實驗來研究在RRBC 系統中不對稱離心力的作用︒通過把對流槽固定在一個偏離轉軸d 的位置上，我們可以得到一個指向性的離心力︒這個對稱性破缺對流場產生了巨大的影響︒流場可視化和角向溫度分佈測量都表明冷熱液體在該離心力作用下分離並且聚集在相對的兩端︒相比於一般的RRBC (即d = 0 mm)，偏心時的傳熱效率有一個急遽增強，隨後達到傳熱最優態（即傳熱最大值）︒通過分析第一階傅立葉模的能量發現，上述傳熱的增加是由流場動力學的改變引起的︒為了理解傳熱的最優態，我們識別出了兩個互相競爭的效應，即該不對稱離心力導致了有助於傳熱的相干性的增強和有礙於傳熱的相干結構尺寸的減小︒在本實驗中，不對稱離心力是疊加在對稱離心力之上的︒進一步的分析發現，總的離心力對冷和熱的液體的效應是不一樣的︒這是因為，對熱的液體而言對稱分佈的離心力和不對稱的離心力是相互抵消的；而對冷的液體而言，兩者則相互促進︒該不對稱離心力和潮汐力的相似性暗示著本實驗的研究結果對一些天文現象有一些潛在應用︒最後一部分研究了水平對流︒與海洋裡洋流的情況類似，在水平對流中加熱和冷卻都是施加在同一個水平面上的︒流場的可視化和溫度剖面顯示，上表面附近存在著強分層的溫度邊界層，而流場內部的分層則很弱︒整個流場大致可以分為三個部分︒從溫度功率譜密度和漲落看出，在不穩定分層的冷區域裡流場湍流度很高，而熱區域裡的流場則很弱︒自由面區域裡的情況則介於這兩者之間︒對於傳熱效率，我們發現了從經典的0.2 Rossby 標度律向0.3 標度律的轉變︒在水平對流系統中，熱區域裡的熱傳導限制了傳熱︒我們發現當冷區域裡的驅動力足夠強時，熱區域裡的液體也會受到流動的影響︒這可能導致了上述傳熱效率的轉變︒同時這也暗示著，在實際洋流中，在低緯度（熱區域）風導致的強混合比在高緯度（冷區域）更重要︒因為在低緯度強混合可以抵消熱傳導所產生的限制︒Hu, Yunbing = 旋轉瑞利-伯納德對流和水平對流的實驗研究 / 胡云炳.Thesis Ph.D. Chinese University of Hong Kong 2020.Includes bibliographical references (leaves 127-140).Abstracts also in Chinese.Title from PDF title page (viewed on 2, November 2021).Hu, Yunbing = Xuan zhuan Ruili-Bonade dui liu he shui ping dui liu de shi yan yan jiu / Hu Yunbing
Bo mo zhong er wei tuan liu re dui liu shi yan yan jiu
No full textThis thesis aims to address two key issues in two-dimensional (2D) convective turbulence: particle dispersion and statistics of the small-scale turbulence.Particle dispersion plays a key role in understanding transport and mixing in turbulence, which is also significant to natural processes such as pollutants spreading in the atmosphere. To study particle dispersion in 2D convective turbulence, we use particle tracking velocimetry (PTV) technique in a soap film. The Taylor-scale Reynolds number of the system is Rλ ≈ 155. It is found that the particle dispersion law strongly depends on the initial separation. In the present system, mean square separations of particle pairs with initial separation in the inertial range grow exponentially and the ones with initial separation close to Kolmogorov length scale follow Richardson scaling law for a short range, which is consistent with the measurement in three-dimensional (3D) case and numerical result. We attribute exponential growth to the fact that the size of thermal plumes, which is regarded as energy injection scale in the present system, is comparable to the integral length scale of the flow, thus, only enstrophy cascading range is achieved for large initial separations, where exponential growth was predicted theoretically. The probability density functions (PDFs) of separation for particle pairs with initial separation close to Kolmogorov length scale display stretched exponential decay and the ones with initial separation in the inertial range exhibit exponential decay. On the other hand, for the particle pairs with initial separation near the integral length scale, Gaussian PDF is observed. The correlation of separation is also found to be initial separation dependent. The single-particle dispersion follow Taylor’s prediction. The acceleration PDF measured in the whole field deviates significantly from Gaussian distribution and displays extreme intermittency, with fluctuations racing up to 60 times of the root-mean-square values.本論文主要研究二維湍流熱對流中的兩個問題：粒子擴散和小尺度湍流的統計特性。粒子擴散不僅對湍流運輸和混合特性的理解至關重要，而且在自然過程，如大氣污染物粒子擴散中扮演重要角色。我們通過粒子示蹤測速的方法，在薄膜中研究了二維湍流熱對流粒子的擴散。該係統對應的泰勒微尺度雷諾數是Rλ ≈ 155。研究發現，當粒子對的初始相對分離落在慣性區時，分離以指數形式增長；而當初始分離接近於Kolmogorov長度尺度時，分離在短時間以Richardson標度律演變，該發現和三維實驗結果以及數值模擬結果一致。分析表明，指數增長是由於粒子被困在相幹結構中，如熱羽流，其尺度與湍流積分長度尺度相當。我們認為，該係統中能量注入尺度即為熱羽流之尺度。這樣，只有渦量級串區在該系統中實現，理論上，可以觀察到分離的指數增長。該研究發現對於解釋污染物顆粒在大氣中長時間聚集有重要意義。研究亦表明，分離尺度接近於耗散區時，分離的概率密度函數以廣義指數形式衰減；落在慣性區時，其概率密度函數以指數形式衰減；接近於積分長度尺度時，以高斯形式衰減。研究表明，分離的相關性也依賴於初始分離。研究表明，單粒子擴散遵循泰勒擴散理論。實驗表明，全場加速度的概率密度函數不同於高斯分佈，並且體現出強間歇性和波動，加速度的波動可以達到特征速度的60倍。Li, Xiangyu = 薄膜中二維湍流熱對流實驗研究 / 李翔宇.Thesis M.Phil. Chinese University of Hong Kong 2014.Includes bibliographical references (leaves 42-45).Abstracts also in Chinese.Title from PDF title page (viewed on 12, October, 2016).Li, Xiangyu = Bo mo zhong er wei tuan liu re dui liu shi yan yan jiu / Li Xiangyu.Detailed summary in vernacular field only.Detailed summary in vernacular field only
lncRNA FR215775 Regulates Th2 Differentiation in Murine Allergic Rhinitis
No full textTo identify the effect of long noncoding RNA (lncRNA) FR215775 in regulating CD4+ T cells on murine models of allergic rhinitis (AR), the expression of lncRNA FR215775 in primary Th2 cells was detected through qRT-PCR. After knocking down the expression of lncRNA FR215775 via Sh-FR215775-Ads, Cell Counting Kit-8, cytometric bead array, and fluorescence-activated cell sorting were performed to determine its functions in vitro. Moreover, lncRNA FR215775-silencing or nonsilencing cells were injected intravenously into AR mice. Then, hematoxylin and eosin, Alcian blue-periodic acid Schiff, and toluidine blue staining were performed, and the levels of IL-2, IL-4, IL-5, IL-6, IL-10, IL-17A, IFN-γ, and TNF in the AR mice were also determined. We found that the expression of lncRNA FR215775 was specifically higher in the murine primary Th2 cells. After the knockdown of lncRNA FR215775, the proliferation of CD4+ T cells was inhibited, and the expressions of IL-4 and IL-5 in the cell culture supernatant were significantly decreased (P < 0.001), along with the percentage of Th2 cells (P < 0.05). The lncRNA FR215775-silencing AR group showed less serious allergic symptoms and a low level of ovalbumin-specific immunoglobulin E (P < 0.01). Meanwhile, the eosinophilia inflammation, goblet cell hyperplasia, and mast cell inflammation in the nasal mucosa all decreased, which indicated attenuated allergic inflammation in the lncRNA FR215775-silencing AR group. In addition, the Th2-related cytokines IL-4 and IL-5 were downregulated in the serum and nasal lavage fluid of this group (P < 0.01). In conclusion, lncRNA FR215775 may play a vital role in the function and differentiation of Th2 cells, which may encourage allergic inflammation. These results may provide significant insights into AR pathogenesis and offer new treatment targets for alleviating AR
Re tuan liu dui liu de shi yan yan jiu
No full textDirect real-space multi-point measurements of the velocity and temperature fields were carried out in various places of the convection cell. In the central region of the cell it is found that both velocity and temperature exhibit the same scaling behavior that one would find for the velocity and for a passive scalar in homogeneous and isotropic Navier-Stokes turbulence. Near the cell's sidewall where thermal plumes abound, vertical velocity and temperature exhibit different scalings. A model, taking into account both buoyancy and energy dissipation, is proposed and its predictions agree well with the sidewall experimental results.This thesis aims to address three key issues in convectioe thermal turbulence: heat transport, statistics of turbulent fluctuations of the velocity and temperature fields, and flow dynamics.Through measurement of 2D velocity at different cross sections of the cylindrical cell with Gamma = 1, we investigate the 3D flow structures and dynamics of turbulent thermal convection. Our result reveals how thermal plumes synchronize their emissions and organize their motions spatially between the top and bottom plates, leading to an oscillatory motion in the bulk region of the fluid. In Gamma = 0.5 small cell, we successfully identified the relationship between 2D instantaneous velocity map and the time-averaged 3D flow pattern. This experiment also showed that a particular value of Nu can be unambiguously associated with a specific large-scale flow mode in the convection cell. By taking into account the effects of the evolution in the circulation path of the mean wind and of the counterflow, we provide a solution to the riddle about the scaling exponent dispersion of the Reynolds number Re with Ra and show that the scaling exponent has a universal value of 0.5.To study the confinement effect on heat transport at high levels of turbulence, we conducted high precision measurements of the Nusselt number Nu as a function of the Rayleigh number Ra in a 1 m diameter cylindrical cell filled with water with aspect ratio Gamma = 0.67, l, 2, 5, 10, 20. The measurements were conducted at the Prandtl number Pr ≃ 4 with Ra varying from 1 x 10 7 to 5 x 1012. It is found that Nuinfinity can be described by a combination of two power laws for all aspect ratios, and that the asymptotic large Gamma behavior may have been reached for Gamma ≥ 10. By studying the statistics of temperature fluctuations inside the conducting plates, we found that the product of temperature skewness and the skewness of temperature time derivative may be used to quantify the intensity of plume emissions.Sun Chao = 熱湍流對流的實驗研究 / 孙超."July 2006."Adviser: Keqing Xia.Source: Dissertation Abstracts International, Volume: 68-03, Section: B, page: 1697.Thesis (Ph.D.)--Chinese University of Hong Kong, 2006.Includes bibliographical references (p. 132-140).Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web.Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web.School code: 1307.Sun Chao = Re tuan liu dui liu de shi yan yan jiu / Sun Chao
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