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Seismic Imaging of the Global Asthenosphere using SS PrecursorsSun, Shuyang 21 September 2023 (has links)
The asthenosphere, a weak layer beneath the rigid lithosphere, plays a fundamental role in the operation of plate tectonics and mantle convection. While this layer is often characterized by low seismic velocity and high seismic attenuation, the global structure of the asthenosphere remains poorly understood. In this dissertation, twelve years of SS precursors reflected off the top and bottom of the asthenosphere, namely, the LAB and the 220-km discontinuity, are processed to investigate the boundaries of the asthenosphere at a global scale. Finite-frequency sensitivities are used in tomography to account for wave diffraction effects that cannot be modeled in global ray-theoretical tomography.
Strong SS precursors reflected off the LAB and the 220-km discontinuity are observed across the global oceans and continents. In oceanic regions, the LAB is characterized by a large velocity drop of about 12.5%, which can be explained by 1.5%-2% partial melt in the oceanic asthenosphere. The depth of the Lithosphere Asthenosphere Boundary is about 120 km, and its average depth is independent of seafloor age. This observation supports the existence of a constant-thickness plate in the global oceans. The base of the asthenosphere is imaged at a depth of about 250 km in both oceanic and continental areas, with a velocity jump of about ∼ 7% across the interface. This finding suggests that the asthenosphere in oceanic and continental regions share the same defining mechanism.
The depth perturbations of the oceanic 220-km discontinuity roughly follow the seafloor age contours. The 220-km topography is smoother beneath slower-spreading seafloors while it becomes rougher beneath faster-spreading seafloors. In addition, the roughness of the 220-km discontinuity increases rapidly with spreading rate at slow spreading seafloors, whereas the increase in roughness is much slower at fast spreading seafloors. This observation indicates that the thermal and compositional structures of seafloors formed at spreading centers may have a long-lasting impact on asthenospheric convections.
In continental regions, a broad correlation is observed between the 220-km discontinuity depth structure and surface tectonics. For example, the 220-km discontinuity depth is shallower along the southern border of the Eurasian plate as well as the Pacific subduction zones. However, there is no apparent correlation between 3-D seismic wavespeed in the upper mantle and the depths of the 220-km discontinuity, indicating that secular cooling has minimum impact on the base of the asthenosphere. / Doctor of Philosophy / In classic plate tectonic theory, the outermost shell of the Earth consists of a small number of rigid plates (lithosphere) moving horizontally on the mechanically weak asthenosphere. In the classic half space cooling (HSC) model, the lithosphere is formed by gradual cooling of the hot mantle. Therefore, the thickness of the plate depends on the age of the seafloor. The problem with the HSC model is that bathymetry and heat flow measurements at old seafloors do not follow its predicted age dependence. A modified theory, called plate cooling model, can better explain those geophysical observations by assuming additional heat at the base of an oceanic plate with a constant thickness of about 125 km. However, such a constant-thickness plate has not been observed in seismology. In this thesis, the asthenosphere boundaries are imaged using a global dataset of seismic waves reflected off the Earth's internal boundaries. Strong reflections from the top of the asthenosphere are observed across all major oceans. The amplitudes of the SS precursors can be explained by 1.5%-2% of partial melt in the asthenosphere. The average boundary depths are independent of seafloor age, and this observation supports the existence of a constant-thickness plate in the global oceans with a complex origin.
The 220-km discontinuity, also called the Lehmann Discontinuity, was incorporated in the Preliminary Reference Earth Model in the 1980's to represent the base of the asthenosphere. However, the presence and nature of this boundary have remained controversial, particularly in the oceanic regions. In contrast to many studies which suggest the 220-km discontinuity does not exist in the global oceans, SS precursors reflected from this interface are observed across the oceanic regions in this thesis. Furthermore, there is a positive correlation between the topography of the 220-km discontinuity and seafloor spreading rate. Specifically, the 220-km discontinuity is smoother beneath slower-spreading seafloors and much rougher beneath faster-spreading seafloors. In addition, the roughness increases faster at slowerspreading seafloors while much more gradual at faster-spreading seafloors. This indicates a close connection between seafloor spreading and mantle convections in the asthenosphere, and seafloors have permanent memories of their birth places. Different melting processes at slow and fast spreading centers produce seafloors with different physical and chemical properties, modulating convections in the asthenosphere and ultimately shaping the topography of the 220-km discontinuity.
Reflections from the 220-km discontinuity are also observed across the global continental regions. In addition, the 220-km discontinuity beneath the continents is comparable to that under oceanic regions in terms of their average depth (∼ 250 km) and velocity contrast across the discontinuity (∼ 7%). In continental regions, there is a general connection between the 220-km depth structure and plate tectonics. For example, the boundary is shallower along the southern border of the Eurasian plate from the Mediterranean region to East Asia where mountain belts were formed as a result of collision between the Eurasian plate and the Nubian, Arabian and Indian plates. Depth perturbations of the 220-km discontinuity are also observed along the Pacific subduction zones including the Cascadia Subduction Zone, Peru-Chile Trench and Japan-Kuril Kamchatka Trench. In addition, depth anomalies are mapped in the interior of continents, for example, along the foothills of high topography in the interior of the Eurasian plate, which may be controlled by far-field convection associated with the convergent processes at the plate boundaries.
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Balancing self with the world and others: Angela Krauß' Romanticism and novel escape from the postmodernHentschel, Graham N. 27 September 2011 (has links)
No description available.
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Himmlische Körper: Hintergrund und argumentative Funktion von 1Kor 15,40fKlinghardt, Matthias 23 June 2020 (has links)
The coherent semantics of the sowing imagery (1Cor 15,36–44) suggest that heavenly bodies (v. 40–41) emerge from a process of body transformation, analogous to plants and animate beings (v. 37–39). The idea that the deceased are transformed into stars and thereby obtain a particular form of existence is widely attested in the mythography and in epitaphs of antiquity. In contrast to pagan conceptions about the dead permanently returning into celestial spheres, the heavenly bodies according to Paul represent a postmortem, albeit a pre-resurrection, stage in the development of human bodies. Accordingly, the heavenly body represents an intermediary ontological mode between the animated body of earthly creatures and the spiritual body of resurrection.
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Healing beliefs and practices of the "Way of Celestial Masters" during the Eastern Han Dynasty (25-220 a.d.)Meng, Qing January 1999 (has links)
Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.
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Demand effects of the falling wage share in AustriaStockhammer, Engelbert, Ederer, Stefan January 2007 (has links) (PDF)
This paper aims at empirically estimating the demand effects of changes in functional income distribution for Austria. Based on a Post-Kaleckian macro model, this paper estimates the effects of a change in the wage share on the main demand aggregates. The results for the behavioral functions for consumption, investment, prices, exports and imports are compared with the specifications of the WIFO macro model and the IHS macro model. A reduction in the wage share has a restrictive effect on domestic demand as consumption decreases more strongly than investment increases. Because of the strong effects on net exports the overall effects of a decrease in the wage share are expansionary. However the latter effect operates only as far as the fall in the wage share increases competitiveness. As wage shares were also falling in Austria's main trading partners, the effect seems to have been neutralized. (author's abstract) / Series: Department of Economics Working Paper Series
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Wage dispersion in non-profit organizations. Do volunteers, donations and public subsidies have an impact?Haider, Astrid, Schneider, Ulrike January 2010 (has links) (PDF)
Existing research in labor economics has rarely accounted for non-profit status in examining wage dispersion. Contrariwise, in non-profit sector research, little has been said so far about (intra-organizational) wage dispersion. Scattered findings from previous work indicate that wage dispersion is smaller in non-profit organizations (NPOs) as compared to for-profits (FPOs). Fairness perceptions and high moral ideals of workers within this sector are often cited as reasons for this assumption. Empirically, however, the reasons for inter-sectoral differences remain obscure. In our analysis, we concentrate on specific characteristics of NPOs as compared to FPOs. More specifically, this paper is to address the question if volunteer workers, donations and public subsidies influence the within-firm wage dispersion in NPOs. In order to answer this research question we use Austrian matched employer-employee data collected in 2006. We estimate an instrument variable regression and find that NPOs that employ volunteer workers and NPOs with a more even mix between paid and unpaid staff display smaller wage dispersion. Donations and public subsidies augment the wage dispersion. (author's abstract) / Series: Working Papers / Institut für Sozialpolitik
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Technologie výroby výztuhy pro automobil / Technology of production reinforcer for carSpurný, Petr January 2009 (has links)
The project, which have been created within the framework study of engineering branch N2301-2, submit technology project of presswork – car reinforcement from material H 220 P and concept of multi-tool set design for pressing operations 1, 2 and 3. Technology process was designed in six operations, based on literary study of blanking and drawing technology. Multi-tool set is design in according with transfer press Müller Weingarten 1250T-1, which was chosen on the basis of advantageousness calculation. Project includes technical and economical evaluation of elaborated technology whit two other variants of production.
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Gott als Erzieher im Alten Testament: Eine semantisch-traditionsgeschichtliche Untersuchung der Begrifflichkeit jsr / musar (paideuo / paideia) mit Gott als Subjekt in den Schriften des ATBetz, Dorothea 29 October 2009 (has links)
Die Arbeit beschäftigt sich mit einem Aspekt des alttestamentlichen Gottesbildes und verfolgt die Traditionslinie der Rede von Gott als einem Erzieher sowohl des Volkskollektivs Israel als auch einzelner Menschen in den Schriften des AT. Ein breit angelegtes Einleitungskapitel zum Thema "Kindheit und Erziehung im Alten Testament" erhellt den zeithistorischen Kontext, in dem die theologische Rede von Gott als Erzieher entstanden ist. Der exegetische Hauptteil konzentriert sich auf die Untersuchung des hebräischen Begriffspaars jsr/musar (vergleiche dazu in der griechischen Übersetzung - Septuaginta - das Begriffspaar paideuo/paideia) und arbeitet die Entwicklungslinie von der Prophetie über den Pentateuch bis in späte Schriften des AT heraus. Insgesamt zeigt sich, dass die göttliche Erziehungsstrategie vor allem strenge Züge hat, dass - eingebettet in den Kontext einer antiken "Prügelpädagogik" - auch der erzieherisch tätige Gott des AT ein vorwiegend strafender Gott ist, der mittels "Züchtigung" das Wohl der Menschen will. Die Frage, inwieweit diese Rede von einem strengen Erzieher-Gott in heutiger Zeit noch nachvollziehbar und tragfähig erscheint, wird in der Schlussbewertung knapp behandelt.
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劉勰論曹操振起鄴下文風的探索: 並據此分析《文心雕龍》書中的文學史觀. / 並據此分析文心雕龍書中的文學史觀 / Exploration of the critique of Liu Xie on Cao Cao in the revival of Yexia wen feng: an analysis of literary historical perspective in Wenxindiaolong / Analysis of literary historical perspective in Wenxindiaolong / Liu Xie lun Cao Cao zhen qi Yexia wen feng de tan suo: bing ju ci fen xi "Wen xin diao long" shu zhong de wen xue shi guan. / Bing ju ci fen xi Wen xin diao long shu zhong de wen xue shi guanJanuary 2005 (has links)
李鳳琼. / "2005年12月" / 論文(哲學碩士)--香港中文大學, 2005. / 參考文獻(leaves 147-155). / "2005 nian 12 yue" / Abstracts also in English. / Li Fengqiong. / Lun wen (zhe xue shuo shi)--Xianggang Zhong wen da xue, 2005. / Can kao wen xian (leaves 147-155). / Chapter 第一章 --- 緒論 --- p.4 / Chapter 第一節 --- 硏究範圍 --- p.4 / Chapter 第二節 --- 硏究目的及意義 --- p.6 / Chapter 第三節 --- 硏究方法 --- p.10 / Chapter 第二章 --- 「三調之正聲」與「韶夏之鄭曲」 一一劉勰論曹操與當時文體之革新 --- p.11 / Chapter 第一節 --- 「區別部類」´ؤ´ؤ《文心雕龍》上篇區分和序列文體的背景與實踐 --- p.12 / Chapter 2.1.1 --- 魏晉南北朝辨析文體的風氣 --- p.12 / Chapter 2.1.2 --- 《文心雕龍》的文、筆二分法 --- p.16 / Chapter 第二節 --- 「務先大體,鑒必窮源」´ؤ´ؤ《文心雕龍》處理文體的原則 --- p.20 / Chapter 第三節 --- 《文心雕龍´Ø樂府》篇與曹操樂府眾作 --- p.23 / Chapter 2.3.1 --- 《文心雕龍´Ø樂府》篇在書中之地位 --- p.23 / Chapter 2.3.2 --- 樂府之「大體」 --- p.25 / Chapter 2.3.3 --- 詩與樂府的「大體」比較 --- p.29 / Chapter 2.3.4 --- 《文心雕龍´Ø樂府》篇的評論對象 --- p.33 / Chapter 2.3.5 --- 曹操雅好音樂 --- p.36 / Chapter 2.3.5.1 --- 音樂類型 --- p.39 / Chapter 2.3.5.2 --- 集結音樂人才與推動鄴下制樂 --- p.44 / Chapter 2.3.6 --- 曹操「傷羈戍」之作 --- p.47 / Chapter 2.3.6.1 --- 〈苦寒行〉 --- p.48 / Chapter 2.3.6.2 --- 〈薤露〉 --- p.52 / Chapter 2.3.6.3 --- 〈蒿里行〉 --- p.55 / Chapter 2.3.7 --- 曹操「傷羈戍」之作與漢樂府同題之作比較 --- p.58 / Chapter 2.3.8 --- 曹操於樂府創作的革新 --- p.59 / Chapter 2.3.8.1 --- 音樂 --- p.60 / Chapter 2.3.8.2 --- 題材 --- p.60 / Chapter 2.3.8.3 --- 語言風格 --- p.62 / Chapter 2.3.8.4 --- 叙事角度 --- p.63 / Chapter 2.3.8.5 --- 主題與功能 --- p.66 / Chapter 2.3.8.6 --- 小結 --- p.67 / Chapter 第四節 --- 劉勰對曹操革新文體之功的評價 --- p.68 / Chapter 2.4. 1 --- 有關曹操樂府作品與鄴下樂府創作的論析 --- p.68 / Chapter 2.4.2 --- 有關曹操革新詔策與章表的論析 --- p.77 / Chapter 2.4.3 --- 小結 --- p.79 / Chapter 第三章 --- 「相王之尊,雅愛詩章」 一一劉勰論曹操與鄴下文風之振興 --- p.80 / Chapter 第一節 --- 劉勰論曹操在鄴下文風之振興中所擔當的角色與發揮的功能 --- p.81 / Chapter 3.1.1 --- 劉勰論「抑丕揚植」的舊談 --- p.82 / Chapter 3.1.2 --- 劉勰論曹丕 --- p.83 / Chapter 3.1.3 --- 劉勰論曹植 --- p.84 / Chapter 3.1.4 --- 曹氏父子的角色與功能 --- p.88 / Chapter 第二節 --- 劉勰論曹操雲集文士 --- p.92 / Chapter 3.2.1 --- 曹操創造安定的創作環境 --- p.92 / Chapter 3.2.2 --- 曹操雅愛文學與禮遇文士 --- p.93 / Chapter 3.2.3 --- 鄴下文士的自由選擇與歸附 --- p.95 / Chapter 3.2.3.1 --- 文士之歸附 --- p.96 / Chapter 3.2.3.2 --- 平等禮遇 --- p.104 / Chapter 3.2.4 --- 曹操對「文才」的賞識 --- p.105 / Chapter 3.2.4.1 --- 鄴下諸子立功的理想 --- p.106 / Chapter 3.2.4.2 --- 鄴下諸子的實際才能 --- p.108 / Chapter 3.2.4.3 --- 文學自覺時代與曹操對文學價値的認知 --- p.110 / Chapter 3.2.5 --- 本節小結 --- p.114 / Chapter 第三節 --- 劉勰論曹操與鄴下創作 --- p.115 / Chapter 3.3.1 --- 劉勰論鄴下作家的創作情態 --- p.117 / Chapter 3.3.1.1 --- 孤獨無偶之苦 --- p.118 / Chapter 3.3.1.2 --- 見知的欣喜 --- p.119 / Chapter 3.3.1.3 --- 六朝擬建安詩的題材 --- p.123 / Chapter 3.3.2 --- 鄴下作品的特色 --- p.128 / Chapter 3.3.3 --- 鄴下作品的風格 --- p.129 / Chapter 3.3.4 --- 本節小結 --- p.133 / Chapter 第四章 --- 劉勰處理文體的方向和他的文學發展觀 --- p.134 / Chapter 第一節 --- 歷史角度:傳統與新變 --- p.135 / Chapter 第二節 --- 強調君主態度與文學發展的關係 --- p.139 / Chapter 第三節 --- 兩相比照的定位方式 --- p.142 / Chapter 第五章 --- 總結 --- p.144 / 【參考書目舉要】 --- p.147
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孫德謙駢文理論研究. / Sun Deqian pian wen li lun yan jiu.January 2006 (has links)
王益鈞. / "2006年12月" / 論文(哲學碩士)--香港中文大學, 2006. / 參考文獻(leaves 230-238). / "2006 nian 12 yue" / Abstracts in Chinese and English. / Wang Yijun. / Lun wen (zhe xue shuo shi)--Xianggang Zhong wen da xue, 2006. / Can kao wen xian (leaves 230-238). / Chapter 第一章 --- 緒論 --- p.1 / Chapter 第一節 --- 孫德謙生平簡介 --- p.1 / Chapter 第二節 --- 《六朝麗指》述略 --- p.6 / Chapter 第三節 --- 硏究動機及方法 --- p.9 / Chapter 第二章 --- 辨體 --- p.12 / Chapter 第一節 --- 引言 --- p.12 / Chapter 第二節 --- 主張駢散合一 --- p.14 / Chapter 〔1〕 --- 不爭文統 --- p.15 / Chapter 〔2〕 --- 宗師六朝 --- p.20 / Chapter 〔3〕 --- 駢散之功用 --- p.25 / Chapter 〔4〕 --- 孫氏「駢散合一」說探源 --- p.29 / Chapter 〔5〕 --- 小結 --- p.30 / Chapter 第三節 --- 駢文與律賦、四六之異 --- p.31 / Chapter 〔1〕 --- 駢文與律賦之別 --- p.31 / Chapter 〔2〕 --- 駢文與四六之異 --- p.35 / Chapter 〔3〕 --- 小結 --- p.39 / Chapter 第四節 --- 對某些駢文體裁的觀點 --- p.39 / Chapter 〔1〕 --- 書序 --- p.40 / Chapter 〔2〕 --- 贈序 --- p.43 / Chapter 〔3〕 --- 連珠 --- p.44 / Chapter 〔4〕 --- 七 --- p.47 / Chapter 〔5〕 --- 墓志 --- p.49 / Chapter 〔6〕 --- 論 --- p.50 / Chapter 〔7〕 --- 檄移 --- p.53 / Chapter 〔8〕 --- 章表牋奏啓 --- p.54 / Chapter 〔9〕 --- 賀牘 --- p.56 / Chapter 〔10〕 --- 小結 --- p.57 / Chapter 第五節 --- 風格 --- p.57 / Chapter 〔1〕 --- 「才氣」與「氣韻」 --- p.58 / Chapter 〔2〕 --- 「繁」與「簡」 --- p.63 / Chapter 〔3〕 --- 「疏」與「密」 --- p.68 / Chapter 〔4〕 --- 陰柔與陽剛 --- p.71 / Chapter 〔5〕 --- 質重與清空 --- p.73 / Chapter 〔6〕 --- 小結 --- p.75 / Chapter 第六節 --- 結語 --- p.76 / Chapter 第三章 --- 修辭 --- p.78 / Chapter 第一節 --- 引言 --- p.78 / Chapter 第二節 --- 對偶 --- p.79 / Chapter 〔1〕 --- 事對 --- p.83 / Chapter 〔2〕 --- 排偶 --- p.88 / Chapter 〔3〕 --- 駢枝 --- p.102 / Chapter 〔4〕 --- 小結 --- p.106 / Chapter 第三節 --- 用典 --- p.107 / Chapter 〔1〕 --- 用典的方法 --- p.100 / Chapter 〔2〕 --- 用典的原則 --- p.118 / Chapter 〔3〕 --- 小結 --- p.129 / Chapter 第四節 --- 鍊字 --- p.129 / Chapter 〔1〕 --- 代字法 --- p.130 / Chapter 〔2〕 --- 字「訛」 --- p.134 / Chapter 〔3〕 --- 虛字 --- p.135 / Chapter 〔4〕 --- 小結 --- p.139 / Chapter 第五節 --- 聲律 --- p.139 / Chapter 〔1〕 --- 自然諧協 --- p.144 / Chapter 〔2〕 --- 輕重緩急 --- p.146 / Chapter 〔3〕 --- 小結 --- p.148 / Chapter 第六節 --- 比興 --- p.148 / Chapter 第七節 --- 形容 --- p.151 / Chapter 第八節 --- 斷插足縮 --- p.154 / Chapter 第九節 --- 結語 --- p.159 / Chapter 第四章 --- 總結 --- p.161 / 附錄一:〈孫德謙年譜初稿〉 --- p.163 / 附錄二:〈孫德謙交遊名錄〉 --- p.225 / 附錄三:參考書目 --- p.229
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