67 research outputs found
Schwinger-Dyson functional in Chern-Simons theory
No full textIn perturbative SU(N) Chern–Simons gauge theory, it is shown that the Schwinger–Dyson equations assume a quite simplified form. The generating functional of the correlation functions of the curvature is considered; it is demonstrated that the renormalized Schwinger–Dyson functional is related with the generating functional of the correlation functions of the gauge connections by some kind of duality trans- formation
Instanton operators in five-dimensional gauge theories
No full textThis article is distributed under the terms of the Creative Commons
Attribution License (CC-BY 4.0), which permits any use, distribution and reproduction in
any medium, provided the original author(s) and source are creditedN.L. is supported in part by STFC grant ST/J002798/1. C.P. is a Royal Society Research Fellow.N.L. is supported in part by STFC grant ST/J002798/1. C.P. is a Royal Society Research Fellow.N.L. is supported in part by STFC grant ST/J002798/1. OPen Aceess funded by SCOAP
Purposeful field trip:Impact on experiential learning opportunities and critical thinking skills
No full textWhile Bloom's taxonomy is a well-established learning hierarchy*higher-order thinking skills (HOTS)*defined as the three upper levels*are seldom attained due to traditional teaching practices and time constraints of units or subjects. Therefore*adopting innovative pedagogy models like experiential learning provides opportunities for the demonstration and development of HOTS. The study's objective shows that field trips are crucial components of experiential learning*and when designed with a purpose*promote higher-order thinking skills. This study used a descriptive design*specifically videos*to collect qualitative data for small sample sizes followed by a structured questionnaire consisting of closed questions. All videos were transcribed*and thematic analyses were used. The quantitative data were analysed descriptively*and data were presented using frequency distribution. It was found that this field trip assessment design enabled the skills demonstration spanning Bloom's learning spectrum. Furthermore*HOTS were used more frequently than basic thinking skills. A quantitative survey on student perceptions revealed that pre-trip activities are equally important as during-trip activities. Findings from this exploratory study provide insights for future education-related research in the field of HOTS*transferable skills*and values.</p
HPLC fucoxanthin profiles of a microalga, a macroalga and a pure fucoxanthin standard
No full textData in this article illustrate representative fucoxanthin chromatograms of a microalga, Chaetoceros calcitrans; a macroalga, Saccharina japonica and; a pure fucoxanthin standard. High performance liquid chromatography (HPLC) eluted fucoxanthin at the 7.008±0.024th min. This data article refers to the research article ‘‘Antioxidant capacities of fucoxanthin-producing algae as influenced by their carotenoid and phenolic contents’’ Foo et al. [1]; where a more comprehensive data interpretation and analysis is explained
Quantum SU(N) Invariants: Introduction, Physical Interpretation and Asymptotic Behavior
No full text本文旨在介紹紐結以及三維流形的量子SU(N) 不變量及其在Chern-Simons 理論下的物理意義。我們首先使用Skein 理論定義Jones 多項式以及把其推廣為Colored Jones 多項式。然後透過對Temperley-Lieb 代數的研究，我們製作出Jones-Wenzl Idempotent。其特別之處在於它在包括Kirby Moves 的多種變換下有良好的性質。由此我們製作出Reshetikhin-Turaev(RTr，或另一標準化的Wr) 和Turaev- Viro(TVr) 三維流形不變量。它們兩者之間有著不平凡的代數關係:jWrj2 = TV .有了以上背景知識，設G 為一李群，我們從量子群Uq(G) 的表示理論來定義Jones 多項式。上一段所討論的不變量正是Uq(SU(2)) 量子不變量。這個方法與前一個的等價關係將會在正文中證明。我們並提供一套Uq(SU(N)) 量子不變量的Skein 理論作為一種推廣。它給出的正是HOMFLY-PT 多項式以及其Colored 版本。另外在這裡我們將提供一份關於SU(N) 的表示論的摘要。文章第三部分的目的在於把上述紐結以及三維流形的不變量以Chern-Simons 理論統一起來。Chern-Simons 理論能夠描述量子不變量的漸近狀態。最後，我們將利用其物理解釋，淺述量子不變量的經典體積猜想和其各種推廣。具體地我們以八字結的計算來驗證以上猜想有多可信。This thesis aims to provide a self-contained introduction to the theory of quantum SU(N) invariant for knot and 3-manifold together with physical interpretation, under the framework of Chern-Simons theory.By using skein-theoretic approach, we first define the classical Jones polynomial and its generalization, the colored Jones polynomial. After that, by studying the Temperley-Lieb algebra, we construct an element called Jones-Wenzl idempotent which is well-behaved under several operations, such as Kirby moves. In particular, it can be used to construct the Reshetihkin-Turaev invariant (RTr, or Wr after normalization) and Turaev-Viro invariant (TVr) for closed oriented 3-manifolds. It turns out that two invariants satisfy a non-trivial relation: jWrj2 = TV .Having the basic knowledge discussed above, we start to define the colored Jones polynomial using the representation theory of the quantum group Uq(G), where G is a Lie group. It turns out that the theory discussed above corresponds nicely to the Uq(SU(2)) quantum invariant.The equivalence of the two approaches will also be proved. As a generalization, we provide a skein theoretic approach of the Uq(SU(N)) quantum invariants. This gives the classical HOMFLY-PT polynomial and its colored version. A brief summary on representation theory of SU(N) will also be given.The third part of this thesis is to unify all these invariants for knots and 3-manifolds under a physical theory called Chern-Simons theory. The Chern-Simons theory can be used to predict the asymptotic behavior of the quantum invariants. We will finally talk about the volume conjecture and its generalizations for the quantum invariants with the help of the physical interpretation. In particular, we will use figure-eight knot to illustrate the validity of the conjectures.Wong, Ka Ho.Thesis M.Phil. Chinese University of Hong Kong 2016.Includes bibliographical references (leaves ).Abstracts also in Chinese.Title from PDF title page (viewed on …).Detailed summary in vernacular field only.Detailed summary in vernacular field only.Detailed summary in vernacular field only.Detailed summary in vernacular field only
Twisted sheaves and SU(r)/Z_r Vafa-Witten theory
No full textThe SU (r) Vafa–Witten partition function, which virtually counts Higgs pairs on a projective surface S, was mathematically defined by Tanaka–Thomas. On the Langlands dual side, the first-named author recently introduced virtual counts of Higgs pairs on μ r-gerbes. In this paper, we instead use Yoshioka’s moduli spaces of twisted sheaves. Using Chern character twisted by rational B-field, we give a new mathematical definition of the SU (r) / Z r Vafa-Witten partition function when r is prime. Our definition uses the period-index theorem of de Jong. S-duality, a concept from physics, predicts that the SU (r) and SU (r) / Z r partition functions are related by a modular transformation. We turn this into a mathematical conjecture, which we prove for all K3 surfaces and prime numbers r
Twisted sheaves and SU(r)/Z_r Vafa-Witten theory
No full textThe SU (r) Vafa–Witten partition function, which virtually counts Higgs pairs on a projective surface S, was mathematically defined by Tanaka–Thomas. On the Langlands dual side, the first-named author recently introduced virtual counts of Higgs pairs on μ r-gerbes. In this paper, we instead use Yoshioka’s moduli spaces of twisted sheaves. Using Chern character twisted by rational B-field, we give a new mathematical definition of the SU (r) / Z r Vafa-Witten partition function when r is prime. Our definition uses the period-index theorem of de Jong. S-duality, a concept from physics, predicts that the SU (r) and SU (r) / Z r partition functions are related by a modular transformation. We turn this into a mathematical conjecture, which we prove for all K3 surfaces and prime numbers r
Manipulation of Microalgal Lipid Production: A Genetic Engineering Aspect
No full textInterests in microalgal lipids as green and renewable energy sources are piquing as cheap hydrocarbon fossil fuels reach their limit. Lipids from microalgae have important human uses, i.e., energy, food, and pharmaceuticals, depending on its quantity and quality. Genetic engineering is the introduction or suppression of a target gene for the selective expression of a bio-product, e.g., hydrocarbons for fuel or polyunsaturated fatty acids (PUFAs) for food, at a favorable quantity. Past studies like nitrogen starvation or salinity stress have shown to increase lipid contents of microalgae; however, studies on the molecular mechanisms underlying these stress-induced lipid productions remain limited. Next, complementing environmental stress manipulation with genetic engineering would potentially be a better and more effective approach to increase microalgae lipid production and accumulation. There are generally two approaches to enhance microalgae lipid production on a molecular level: firstly, overexpression and improvement of key enzymes involved in fatty acid and isoprenoid biosynthesis and, secondly, repression of lipid catabolic and competitive pathways such as beta-oxidation and starch synthesis. This review provides an update of microalgae lipid research findings to date and aims to address recent system biology discoveries and approaches on microalgae lipid production, the roadblocks encountered, and help needed to realize the ultimate goal, that is, microalgal lipids as sustainable resources for energy and high-value products
Storage and degradation kinetics of physicochemical and bioactive attributes in microalgal-derived fucoxanthin-rich microcapsules
No full textMicroencapsulation can improve carotenoid stability by slowing down degradation. Studies on the production and processing effects of microencapsulated carotenoids were reported in the past however long-term storage studies on fucoxanthin stability remains limited. This study investigated the effects of an eighteen-week storage period across four conditions on fucoxanthin derived from the diatom, Chaetoceros calcitrans. The fucoxanthin powders were prepared using two microencapsulation methods i.e., freeze drying and spray drying. Briefly, the microcapsules produced were stored in amber bottles under room temperature (25 °C) or refrigerated (4 °C) in the dark or in the presence of light. Samples were collected every two weeks where the physicochemical characteristics, carotenoid stability and antioxidant activity were evaluated. It was found that the freeze-dried microcapsule stored in 4 °C showed significantly (p 25 °C (dark) > 40 °C (dark) > 25 °C (light). This finding offer useful insights into optimizing fucoxanthin microencapsulation methods, maintaining product quality during storage and distribution, and ensuring compliance with quality standards of fucoxanthin-based products available to consumers across the production and distribution chain
[[alternative]]A Study on The Intoning-matters Words of Su Dong-po
No full text[[abstract]]本論文以 蘇東坡詠物詞研究 為論題,主要著眼於東坡詠物詞的風貌 特色,以及東坡詠物詞在詠物詞發展史上的意義來探討.茲將所採用的研究方法與步驟略述如下:首先,分述研究動機 研究方法 詠物詞的義界 選材原則,以作為本論文研究依據.其次,任何一種文學的產生,都不外受到社會 文學自身發展 作家本人三方面因素的影響,然而作家個人因素是東坡寫作詠物詞的重要背景因素,因此本論文將以上三種因素調整為詠物詞發展的趨勢 東坡的文學創作觀 東坡的生平遭遇三層面,以作為東坡詠物詞的創作背景,並以此為本文論述的基礎.又其次,歸納分析東坡詠物詞的題材,以見出東坡取材的情形;然後再就東坡詠物詞中較常歌詠或具特殊意義的題材作意象分析.物象意義的呈現雖受作家個人主觀的認識 主觀的情意感受所影響,然而亦多根源於該物本身的特質或文化歷史的典故,因此在意象分析部份,本文主要以此二層面為論述主軸,以了解該物在中國文學中普遍的物象意義,進而與東坡詠物詞中的意象使用作比較,以了解東坡詠物詞中意象使用的趨勢與特色.再其次,將東坡詠物詞就其內涵先概分為體物和寄託兩大類,而體物類再析分出花卉類 樂器類 女子類 其他四類;寄託類再析分為託物詠懷 狀物抒情 詠物寓理三類,每類列舉東坡詠物詞例,並詳加說明解析,以了解東坡詠物詞中所蘊含的思想情意.再者,詠物詞的寫作要則,一般要求 不留滯於物 不黏不脫 不即不離 的藝術效果,本文以現代修辭學解剖東坡的詠物詞作,以了解東坡詠物詞的藝術效果,以及東坡詠物詞的寫作技巧特色.最後,總括各章節的研究成果,作一重點整理,呼應本文的研究動機,簡述東坡詠物詞在中國文學上的意義與價值.
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