609 research outputs found
The -space
In this paper, we introduce the concept of -spaces. We find that
strong -spaces are -spaces, but the converse does not hold. We
give a characterization for a topological space to be a -space. We
prove that the retract of a -space is a -space. We obtain
the result that for any space and , if the function space
endowed with the Isbell topology is a -space, then is
a -space. We also show that for any space , if the Smyth
power space is a -space, then is a -space.
Meanwhile, we give a counterexample to illustrate that conversely, for a
-space , the Smyth power space may not be a
-space
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An Examination of Effects of Self-Concept (SC), Destination Personality (DP), and SC-DP Congruence on Tourist Behavior
Tourism literature has explored some critical concepts such as motivation, image, expectations and the like. However, such constructs as self-concept, destination personality, and self- congruence, have received little attention. This paper makes an effort to address these concepts by proposing and empirically testing a theoretical model that attempts to investigate the structural relationships between destination personality (DP), self-concept (SC), congruence between self-concept and destination personality (SC-DP congruence) and tourist behavior. The findings suggest significant influences of these concepts on tourist behavior. An understanding of what influences tourist behavior can aid in designing and implementing appropriate marketing programs
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A Special Event Loyalty Model: Comparing First Time and Repeat Attendees
Materials Characterization at High Speed by Dynamic Tensile Tests
In this paper, the dynamic deformation behaviors of 2 aluminum alloys (AA6016, AA5182) and 2 steels (v 1158, FeP04) are investigated. Firstly, the test method, an improved Hopkinson pressure bar test, is introduced. Then, the test results are presented and analyzed. The strain rate range used in this study is between 290 s^(-1) and 1750 s^(-1).The test results show that the yield stresses of all four tested materials increase along with the increase of strain rate, but the ductility does not. An interesting finding is that the tested Al alloys demonstrated larger elongation than those of steels. In conventional tensile tests, as it is well known, the tensile elongation of low carbon steels is usually much higher than the one of Al alloys. So, it can be predicted that the aluminum alloys could have better formability than the steels in high speed forming processes, though the underlying mechanism is not fully understood
Micro- and Nano Engineering for Polymerase Chain Reaction
In the frame of this thesis, polymerase chain reaction (PCR) is analyzed from analogue to digital, from thermal cycling to a single temperature. An "analogue" measurement infers certain measurements based on the measured pattern, whereas a "digital" measurement method measures a variable quantitatively and discretely. First, an open system with a thermal gradient feature to optimize PCR is described. The gradient is measured through encapsulated aqueous beads of a temperaturedependent dye with volumes in the low microlitre range within slightly larger oil droplets, forming virtual reaction chambers (VRCs). VRCs exploit the advantages of microfluidics and droplets in a simple way while circumventing many practical problems. As the gradient feature allows for testing a range of annealing temperatures simultaneously, the optimal annealing temperature can be determined easily in a single run. Second, a microfluidics platform using capillaries was built to generate nanoscale droplets. Those monodisperse, isolated compartments are used as nano-reactors for isothermal PCR – recombinase polymerase amplification (RPA). By precise definition of the starting time of RPA, the method detects nucleic acid at the single molecule level by counting the presence or absence of the amplification of individual molecules confined to isolated compartments. Third, a biomimetic chip with a nanowell structure was duplex-imprinted from a natural insect, Cicada, to run digital PCR. The glassy wings of Cicada, which are abundant in nature, exhibit a strikingly highly organized nanopillar structure over its membrane on both sides. A duplex nanoimprint technique was proposed to fabricate the chip out of the cleanroom, which combines the top-down and bottomup nanofabrication technique to speed up the fabrication process and achieve higher throughput. Further experiments for digital PCR using the Cicada chip are II still ongoing. Additionally the Cicada nanowell chips has a potential to be employed in other applications, such as nanoparticles self-assembly, Matrix assisted laser desorption ionization (MALDI) etc.Im Rahmen dieser Arbeit wurde die Polymerase-Kettenreaktion (Polymerase chain reaction; PCR) untersucht, von Analog bis Digital als auch bei zyklisch wechselnden Temperaturen und festen Temperaturwerten. Eine „digitale“ Messung misst hierbei quantitativ und eigenständig eine bestimmte Variable, wohingegen „analoge“ Messungen bestimmte Messwerte extrapolieren, basierend auf einem gemessenen Muster. Zuerst wird ein offenes System mit einem Temperatur-Gradienten zur Optimierung der PCR beschrieben. Der Gradient wurde vermessen mittels verkapselter, wässriger Mikrobeads mit einem temperaturabhängigen Farbstoff mit Volumina im niedrigen Mikroliter-Bereich innerhalb leicht größerer Öltropfen, die hierbei eine Virtuelle Reaktionskammer (VRC) bilden. VRCs stellen einen simplen Weg zur Untersuchung der Vorteile der Mikrofluidik und Droplettechnologie dar, wobei viele praktische Probleme verhindert werden können. Durch die Eigenschaften des Gradienten war es möglich, eine große Breite von Temperaturen zu testen, um die optimale Annealing-Temperatur in einem einzelnen Experiment zu ermitteln. Zweitens wurde eine mikrofluidische Plattform hergestellt, um Tropfen in Nano- Größe zu generieren. Diese monodispersen, isolierten Kompartimente wurden als Nanoreaktoren für isothermale PCR-Rekombinase Polymerase Ampifikation (RPA) verwendet. Durch genaue Definition der Startzeit der RPA konnte die Methode verwendet werden, um Einzelmoleküle von Nucleinsäuren nachzuweisen über Präsents oder Absenz einer Amplifikation des jeweiligen Moleküls in den isolierten Kompartimenten. Drittens wurde ein bio-mimetischer Chip mit Nanowell-Strukturen für PCR als Duplex-Abdruck eines Insektes, Cicada, geformt. Die Glasflügel von Cicada, welche in großer Fülle in der Natur vorliegen, besitzen eine hoch-organisierte NanopillarIV Struktur, verteilt über die Membranen auf beiden Seiten. Eine Duplex- Nanoabdruck Technik wurde verwendet, um die Chips außerhalb eines Reinraums herstellen zu können, was sowohl die Top-Down- als auch die Bottom-Up- Nanoherstellungstechniken kombiniert, um somit den Fabrikationsprozess beschleunigen und einen höheren Durchsatz generieren zu können. Weitere Experimente mit dem Digital-PCD Cicada Chip sind in Vorbereitung. Des Weiteren hat der Cicada Nanowell-Chip großes Potential in unterschiedlichen Anwendungen weiter genutzt zu werden, wie beispielsweise selbstorganisierende Nanopartikel, Matrix-assisted laser desorption ionization MALDI etc.本论文从模拟到数字,从热循环到单一温度对聚合酶链式反应(PCR)
进行了分析。“数字”测量方法定量且离散地测量某个变量,而“模
拟”测量则是基于测量的模式推断某些测量结果。
首先,本文描述了一个开放的,用于优化PCR 的温度梯度系统。温度
梯度通过温度依赖性荧光染料的胶囊化水珠测量。水珠的体积在低微
升范围内,外面被体积稍大的油滴包裹起来,形成虚拟反应室(VRC)。
由于梯度特征允许同时测试一系列退火温度,所以可以在单个实验中
很容易地确定最佳退火温度,从而达到优化PCR 的目的。
其次,本文介绍了一个基于毛细管的微流体平台,用来产生纳米级的
液滴用于运行数字液滴PCR。这些单分散的液滴隔离室被用作等温
PCR – 重组酶聚合酶扩增 (RPA) 的纳米反应容器。通过精确定义RPA
的起始时间,该方法计数被限制在隔离液滴中的单个分子的扩增结果
的存在与否达到检测单分子水平核酸的目的。
最后,本文介绍了具有纳米孔结构的仿生芯片,用以运行数字PCR。
该创意是从天然昆虫 - 蝉(Cicada)得到灵感。蝉在自然界储藏丰富,
它的透明翅膀在膜的正反面上呈现出惊人的高度有序的纳米柱状结构。
本文的第六章提出了一种双面纳米压印技术,无需无尘室制造芯片,
将自上而下和自下而上的纳米加工技术结合起来,以加快制造过程并
实现更高的生产量。由于检测仪器的限制,使用Cicada 芯片的数字
PCR 实验仍在进行中。此外,蝉纳米芯片将用于其他应用,如纳米粒
子自组装,基质辅助激光解吸电离(MALDI)等
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Authenticity and Nostalgia: A Gastronomic Experience of a Local Food Night Market
The purpose of this study was to explore the roles of authenticity (food authenticity and atmosphere authenticity) and nostalgia in tourist’ food experiences. Data were collected with tourists visiting a local food night market in Macao. CFA and SEM were used for data analysis. Results suggested that authenticity, especially atmosphere authenticity, has a positive influence on nostalgia, which in turn influences attitude towards local food, perceived gastronomy destination image, as well as revisit intention for food consumption. The findings also provide some practical implications for the food night market as well as DMOs
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