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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

The 1988 Lancang-Gengma, China, earthquake sequence : teleseismic body wave, surface wave and strong ground motion studies

Li, Xiao-qing, 1963- 06 August 1991 (has links)
On November 6, 1988, two strong earthquakes (Mw: 7.0 and 6.8) separated by about 13 minutes occurred in Yunnan Province, China. The aftershocks located by Kunming Telemetered Seismic Network form a lineament approximately 120 km long and 20 km wide with the long dimension oriented approximately N30°W. The epicenter of the first event lies about 30 km from the southern terminus of the aftershock zone while the epicenter of the second event is 60 km further to the northwest. Field investigations indicate that the surface fault ruptures associated with the first and second shock and a variety of ground deformations. We analyze teleseismic data recorded by the GDSN network to determine the rupture process of these two mainshocks (referred to as Ml and M2) and the two largest aftershocks (referred to as Al and A2). Inversion of long-period body waves gives the following centroid source parameters for Ml: strike 154°±4°, dip 86°±1°, slip 181°±1°, centroid depth shallower than 15 km (least-misfit centroid depth 12 km), and seismic moment 4.5-4.9 X 10²⁶ dyn cm (least-misfit seismic moment 4.6 X 10²⁶ dyn cm). The source time function, further constrained by broadband seismograms, indicates that the source duration for this event is 12 seconds. Due to signal interference with Ml, body wave inversion techniques cannot be applied to M2. The Rayleigh waves provide a better look at this event. In order to identify the energy contributions from the two events, group velocity analysis was performed on the surface wave trains. The energy from the individual events was then isolated based on their dispersion patterns. The amplitude spectra in the period range of 100 to 66 s were inverted for the source parameters. The inversion constrains the strike of M2 precisely (155°±3°), however, dip and slip angles were not well resolved by the inversion. Similar Rayleigh wave amplitude spectra and radiation patterns of Ml and M2, however, suggest that they had very similar mechanisms and centroid depths. On the average, the amplitude spectra of M2 are smaller than those of Ml by a factor of 2.2, indicating the seismic moment of M2 is 2.1 X 10²⁶ dyn cm. The two largest aftershocks, Al (Mw 6.1) and A2 (Mw 5.3), which occurred at the southern terminus of the aftershock zone, were analyzed by modeling teleseismic and strong ground motion data. Teleseismic body wave inversion gives source orientation of Al: strike 165°±2.5°, dip 90°±1.5°, slip 178°±0.5°, centroid depth shallower than 12 km (least-misfit centroid depth 7 km from broadband waveform inversion), and seismic moment 1.5-1.6 X 10²⁵ dyn cm. The inversion of A2 gives the source orientation and centroid depth very similar to those of Al. The seismic moment for this event is 1.3-1.6 X 10²⁴ dyn cm. Modeling of strong ground motion seismograms adds more constraints on centroid depths and source time functions of Al and A2. To minimize the effect of scattering caused by upper crustal heterogeneity, we confined our analysis to frequencies lower than 1 Hz. A crustal model, with a low velocity sedimentary layer, was found that predicts common features of observed strong ground motion seismograms for both events. Derived source orientation is consistent with that found from teleseismic body wave inversion. The centroid depths of Al and A2 were constrained to be between 4 and 12 km. A source duration of 7 s and 2 s was obtained for Al and A2, respectively. Derived rupture parameters of Ml and M2, aftershock distribution, field investigations, geological information and concepts of geometrical barriers and fault asperities, indicate that the preexisting fault intersections played the key role in rupture terminations and initiations. The 12 s source duration of Ml and about 60 km long zone of ground deformation along the strike suggest that Ml rupture was bilateral. The rupture initiated near a fault intersection and propagated to NNW and SSE along the strike. The SSE propagating rupture was terminated by a preexisting fault which intersects the ruptured fault 30 km to the south. The aftershock Al and A2 as well as a dense group of small aftershocks were associated with the termination of the SSE segment. The NNW propagating rupture was also terminated by a NE striking preexisting fault on which several of the largest aftershocks appear to have occurred. This NE striking fault right-laterally offsets the fault on which Ml and M2 occurred forming a geometrical barrier for the rupture. M2 presumably nucleated near this barrier and unilaterally ruptured about 25 km toward NNW where it was terminated by a well documented preexisting fault. / Graduation date: 1992
22

Socio-ecological vulnerability in a Tibetan village on the Lancang River, China

Galipeau, Brendan A. 06 July 2012 (has links)
This ethnographic research examines socioeconomic vulnerabilities to resettlement from a large hydropower dam and agricultural commodification in a Tibetan village in Yunnan Province, Southwest China. After providing an initial background on the dynamics of the research region and hydrodevelopment on its rivers, the research framework of examining vulnerability through a lens of political ecology and local knowledge is outlined. Utilizing this framework, the socioeconomic strategies surrounding agriculture and commodified forest products within the study village are initially outlined through the use of oral histories, previous literature, and quantitative household survey data. After providing a detailed background on these income strategies, vulnerabilities to resettlement are examined through qualitative analysis of individual household interviews. This analysis shows that village households are highly reliant on the village's specific location in order to collect the resources and pursue the agriculture that they do; making them vulnerable to future resettlement. The analysis also shows that in the opinions of villagers, a good standard of living is significantly defined by their ability to pursue specific economic strategies. Next, interview results are analyzed to show how agricultural commodification and a very high reliance on one government sponsored company to purchase crops has also made the village highly vulnerable economically. The thesis concludes with reflections on future hydrodevelopment and resettlement scenarios within the village, and provides recommendations to improve local level resilience and promote better capacity to adapt to change. / Graduation date: 2013
23

The Va : traditional culture and modernization of a minority nationality in China

Chiang, Hung-i, Jiang, Hongyi 03 April 1992 (has links)
The Va nationality, despite its small population compared to other nationalities in China, has preserved most of its traditions largely due to limits placed by historical circumstances and geographical isolation. To non-Chinese anthropologists, the Va people still remain unknown, as there is little or no information about them in English or other Western languages. One of the purposes of this study is to narrow this gap by presenting an ethnographic description of the Va, giving them a place in the world anthropological studies. Since the Va have retained their own cultural characteristics, their societal development has been rather slow. Part of the reason for this slow development is inherent in the basic nature of Va culture, and part of it lies in misguided administrative policies and programs. This study proposes ways to help the Va make progress toward development without destroying their culture and examines several possible ways of modifying or revamping government policy and programs directed toward the Va people. / Graduation date: 1992
24

Understanding ethnic multilingual learners at tertiary level : an ethnographic case study in Yunnan, China

王革, Wang, Ge January 2011 (has links)
Existing research on multilingual acquisition indicates that multilingual learners confront challenges not only in mastering new linguistic forms, but also in forming new identities, and especially when the languages concerned are socially and linguistically distant. This study shows that ethnic minority students in China (referred in particular as ‘ethnic multilingual learners’ or EMLs in this study) at universities can face more challenges than the ethnic majority, Han, when they choose to study English as their major subject. The Han’s content and method in English learning are straitjacketed upon them. The environment is unfamiliar to EMLs, and the EMLs are often regarded as “strangers” to the place. Their problems include the national examination system, medium of instruction, learning difficulties, psychological issues and cultural exclusion. The current educational policies in China intend to protect the educational rights of ethnic minorities, but ignore the role of education in inheriting and capitalizing their ethnic cultures. The current university curricula mainly focus on subject knowledge building and patriotic education. As a result, the “cultural self-consciousness” and “cultural capital” of EMLs are less emphasized and encouraged. Data are collected on two female ethnic minority students at Yunnan University of Nationalities (YUN) through ethnographic interview, autobiography, oral narrative, online chatting and field observation. It provides information at a micro level, on how the two students, who have successfully navigated through Chinese education system to the tertiary level, try their best to excel in the education system of YUN with English language as their major subject and construct their multiple identities, and what important factors are affecting such identity construction. The findings suggest that they negotiate their multiple identities successfully through their active engagements on and off the university campus to become legitimate participants in various “communities of practice”. These identities are shaped partly by their own heritage and partly by the present sociopolitical realities in China. Drawing mainly on poststructuralist and multicultural education theories, the study also examines the power relationship exercised in YUN and discusses the impact of this power relationship on the identities formation of the target informants. The national and local policies as well as the curriculum structures of YUN are analyzed to identify the implicit power relationship that mainly causes tensions to the education and language learning of EMLs. It is argued that multiculturalism, as a discourse of education, may help to ease the tension between being an ethnic minority and a Chinese national, and reduce the danger of assimilation and marginalization of these EMLs. To achieve the goal of multilingual education based on the notion of multiculturalism, a “collaborative” power relationship which facilitates the empowerment rather than disempowerment of EMLs should be the goal in China according to the framework of “ethnic diversity within national unity”. It is envisaged that with such multicultural mentality, EMLs will be more able to act not only as manpower for raising productivity of the country, but also as agents for social transformation and in the end become citizens of the cosmopolitan world. / published_or_final_version / Education / Doctoral / Doctor of Philosophy
25

Utilising solar energy within conventional coal fired power stations.

Baziotopoulos, Con, mikewood@deakin.edu.au January 2002 (has links)
Although the thermodynamic advantages of using solar energy to replace the bled off steam in the regeneration system of Rankine cycle coal fired power stations has been proven theoretically, the practical techno/economic feasibility of the concept has yet to be confirmed relative to real power station applications. To investigate this concept further, computer modelling software “THERMSOLV” was specifically developed for this project at Deakin University, together with the support of the Victorian power industry and Australian Research Council (ARC). This newly developed software simulates the steam cycle to assess the techno/economic merit of the solar aided concept for various power station structures, locations and local electricity market conditions. Two case studies, one in Victoria Australia and one in Yunnan Province, China, have been carried out with the software. Chapter one of this thesis defines the aims and scope of this study. Chapter two details the literature search in the related areas for this study. The thermodynamic concept of solar aid power generation technology has been described in chapter three. In addition, thermodynamic analysis i.e. exergy/availability has been described in this chapter. The “Thermosolv” software developed in this study is detailed in chapter four with its structure, functions and operation manual included. In chapter five the outcomes of two case studies using the “Thermosolv” software are presented, with discussions and conclusions about the study in chapters 6 and 7 respectfully. The relevant recommendations are then made in chapter eight.
26

A New Tsuga Species From the Upper Miocene of Yunnan, Southwestern China and Its Palaeogeographic Significance

Xing, Yao Wu, Liu, Yusheng Christopher, Su, Tao, Jacques, Frédéric M.B., Zhou, Zhe Kun 01 December 2013 (has links)
A new fossil species, Tsuga xianfengensis Xing et Zhou, n. sp., is reported based on two compressed seed cones. The fossil cones were discovered from the upper Miocene Xiaolongtan Formation at the Xianfeng Basin of Yunnan, southwestern China. The discovery of the Tsuga cones confirms the presence of Tsuga in the Miocene of central Yunnan and represents the earliest Tsuga macrofossils in the southwestern China. The new species reveals a close affinity with East Asian Tsuga species, T. chinensis and T. dumosa. It provides fossil evidence to support the molecular data that the Asian clade might be differentiated in the Miocene.
27

A New Quercus Species From the Upper Miocene of Southwestern China and Its Ecological Significance

Xing, Yaowu, Hu, Jinjin, Jacques, Frédéric M.B., Wang, Li, Su, Tao, Huang, Yongjiang, Liu, Yu Sheng Christopher, Zhou, Zhekun 17 June 2013 (has links)
Quercus praedelavayi Xing Y.W. et Zhou Z.K. sp. nov. is reported from the upper Miocene of the Xianfeng flora in central Yunnan, southwestern China. The fossil species is identified based on the detailed leaf morphological and cuticular examinations. The primary venation is pinnate and the major secondary venation is craspedodromous with regular spacing. Stomata are anomocytic and occur on abaxial epidermis. Trichome bases are unicellular and multicellular. The new fossil species shows the closest affinity with Quercus delavayi, an extant species distributing in southwestern China. The responses of the functional leaf traits to the climate change were studied by comparing the leaf characters of fossil species and its nearest living relative. The stomatal density of Q. praedelavayi is higher than Q. delavayi, which suggests a lower palaeoatmospheric CO2 concentration during the late Miocene. The trichome base density of Q. praedelavayi is higher than the extant Q. delavayi. Considering the palaeoclimatic reconstruction of Xianfeng flora, it rejected the hypothesis that increase in trichome density is an adaptation to the drier environment.
28

First Discovery of Cucubalus (Caryophyllaceae) Fossil, and Its Biogeographical and Ecological Implications

Huang, Yong Jiang, Liu, Yu Sheng, Jacques, Frédéric M.B., Su, Tao, Xing, Yaowu, Zhou, Zhekun 05 March 2013 (has links)
A new species of Cucubalus is described based on two fossil seeds recovered from the upper Pliocene Sanying Formation in northwestern Yunnan Province, southwestern China. The seeds are characterized by a reniform to circular outline in shape, and sinuous and discontinuous rugulae made of rod-like elements radiating from the hilum region to the dorsal margin. The combination of these characteristics shows their close resemblance to the extant genus Cucubalus in the Caryophyllaceae. A morphological principal coordinates (PCO) analysis further supports the assignment to this genus. Cucubalus is a monotypic genus today, but the late Pliocene fossil seeds have been described as a new species, Cucubalus prebaccifer Huang, Liu et Zhou, sp. nov. This newly documented Cucubalus fossil, representing the first fossil record of this genus, implies that the genus has existed in northwestern Yunnan, southwestern China, at least since the late Pliocene. It provides important information on the past biodiversity and biogeography of both the genus Cucubalus and the fossil-scant family Caryophyllaceae.
29

A New Tsuga Species From the Upper Miocene of Yunnan, Southwestern China and Its Palaeogeographic Significance

Xing, Yao Wu, Liu, Yusheng Christopher, Su, Tao, Jacques, Frédéric M.B., Zhou, Zhe Kun 01 December 2013 (has links)
A new fossil species, Tsuga xianfengensis Xing et Zhou, n. sp., is reported based on two compressed seed cones. The fossil cones were discovered from the upper Miocene Xiaolongtan Formation at the Xianfeng Basin of Yunnan, southwestern China. The discovery of the Tsuga cones confirms the presence of Tsuga in the Miocene of central Yunnan and represents the earliest Tsuga macrofossils in the southwestern China. The new species reveals a close affinity with East Asian Tsuga species, T. chinensis and T. dumosa. It provides fossil evidence to support the molecular data that the Asian clade might be differentiated in the Miocene.
30

A New Quercus Species From the Upper Miocene of Southwestern China and Its Ecological Significance

Xing, Yaowu, Hu, Jinjin, Jacques, Frédéric M.B., Wang, Li, Su, Tao, Huang, Yongjiang, Liu, Yu Sheng Christopher, Zhou, Zhekun 17 June 2013 (has links)
Quercus praedelavayi Xing Y.W. et Zhou Z.K. sp. nov. is reported from the upper Miocene of the Xianfeng flora in central Yunnan, southwestern China. The fossil species is identified based on the detailed leaf morphological and cuticular examinations. The primary venation is pinnate and the major secondary venation is craspedodromous with regular spacing. Stomata are anomocytic and occur on abaxial epidermis. Trichome bases are unicellular and multicellular. The new fossil species shows the closest affinity with Quercus delavayi, an extant species distributing in southwestern China. The responses of the functional leaf traits to the climate change were studied by comparing the leaf characters of fossil species and its nearest living relative. The stomatal density of Q. praedelavayi is higher than Q. delavayi, which suggests a lower palaeoatmospheric CO2 concentration during the late Miocene. The trichome base density of Q. praedelavayi is higher than the extant Q. delavayi. Considering the palaeoclimatic reconstruction of Xianfeng flora, it rejected the hypothesis that increase in trichome density is an adaptation to the drier environment.

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