• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 3
  • 1
  • 1
  • Tagged with
  • 7
  • 7
  • 3
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 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.
1

Lagerstroemia (Lythraceae) Pollen from the Miocene of Eastern China

Liu, Yu, Zetter, Reinhard, Ferguson, David K., Zou, Charley 01 December 2008 (has links)
A newly discovered fossil pollen taxon is described as Lagerstroemia cathayensis sp. nov. on the basis of a combination of morphological characters including prolate shape with no or weakly developed pseudocolpi and rugulate-verrucate tectum. The fossil pollen was recovered from a Miocene deposit in Zhejiang province, eastern China. It resembles pollen of extant Lagerstroemia subcostata Koehne and L. limii Merrill, both species still occurring near the fossil site in Zhejiang province and further extending into other regions of southern China, Japan, India and the Philippines. This record represents the only description of Cenozoic pollen grains of the genus Lagerstroemia from East Asia examined by means of scanning electron microscopy. The occurrence of Lagerstroemia together with some temperate plants (i.e. Keteleeria, Acer, Carpinus, Fagus) at the fossil site suggests that the climate in eastern China during the Miocene was similar to that of today.
2

Human exposure to mercury and other elements in Eastern China

FANG, TIAN 03 May 2011 (has links)
Mercury contamination is a global issue due to its neurotoxicity, and China is not an exception due to its increasing industrialization. Fish is of the most concern, in respect to human exposure to mercury, because fish accumulates methylmercury through food chain in aquatic systems. The province of Zhejiang is renowned for its cuisine that incorporates freshwater fish. Qiandao Lake, in Zheijang, was the site of a case study examining the link between the total mercury (THg) concentration in hair samples and fish consumption. A questionnaire survey and hair sampling were carried out on women of childbearing age (17-46 years) from a fishing town by Qiandao Lake. The average hair THg concentration was 0.76±0.51μg/g dw. The most-frequently consumed species included four species of carp (golden, bighead, silver and predatory) and the Mongolian redfin. Hair THg concentrations accumulated rapidly during younger years, reaching a plateau around age 25, implying that the hair mercury concentrations in adult females >25 years can be interpreted by environmental exposure. Hair THg concentrations were positively correlated both with the frequency and the average weekly amount of fish consumption. This indicates that fish consumption is an important contributor to hair mercury concentrations in the absence of occupational or environmental mercury sources. A positive correlation between selenium and mercury in hair samples was also observed, suggesting a possible antagonistic relationship. This is the first study to look at mercury exposure in an eastern China community dependent on freshwater fish. This study also compared element trends (Mg, Ca, Cr, Mn, Cu, Zn, As, Se, Pb) in hair samples from three groups: 50 residents by Qiandao Lake (QD), 17 people from Fudan University, China (FU), and 20 people from Queen’s University, Canada (KI). Trends of mean Mg, Cu, Ca, As concentrations among groups are the same (KI>FU>QD). Mn, Cr, and Hg share the same trends of QD>FU>KI. Se concentrations follow the trend of QD>KI>FU. Strong correlations between Ca and Mg were observed within each group. Relationships between Se and Hg are clear in QD but not in FU and KI, probably due to the different dietary proportion of fish. / Thesis (Master, Environmental Studies) -- Queen's University, 2009-12-14 11:52:06.906
3

Fokienia Shengxianensis SP. Nov. (Cupressaceae) From the Late Miocene of Eastern China and Its Paleoecological Implications

He, Wenlong, Sun, Bainian, Liu, Yu Sheng Christopher 01 June 2012 (has links)
Twenty-one fossil foliage, identified as Fokienia shengxianensis sp. nov. (Cupressaceae), were collected from the upper Miocene Shengxian Formation in Tiantai and Ninghai counties, Zhejiang Province of eastern China. These fossils can likely be distinguished from other extant genera in the family Cupressaceae s.l. except Fokienia by leaf external morphology alone. Foliar cuticular comparison with the only modern species in this genus, Fokienia hodginsii Henry et Thomas, further suggests that the present fossil species closely resembles the modern counterpart. Paleoecologically, the occurrence of Fokienia from the Shengxian Formation appears to support that the fossil site was covered by subtropical evergreen broad-leaved forest and under warm and humid conditions during the late Miocene, consistent with evidence from previously published fossil plants.
4

Discriminating Fossil Evergreen and Deciduous Quercus Pollen: A Case Study From the Miocene of Eastern China

Liu, (Christopher) Yu, Zetter, Reinhard, Ferguson, David K., Mohr, Barbara A.R. 01 July 2007 (has links)
In palaeopalynology oaks are rarely identified beyond the generic level. In order to recognize fossil evergreen and deciduous oak pollen, we compiled distinguishing criteria from the literature, most under the SEM, on the living oaks. One of the most significant criteria is the nature of the sculpturing under the SEM. Evergreen oak pollen exhibit at least four kinds of sculpturing, viz. rod-like elements, uniformly fine granules, scabrate-verrucate, and rugulate micromorphology. The first two types of sculpturing are mostly limited to the evergreen oaks and can be used to identify fossil evergreen oak pollen, while the last two types can also be seen in many deciduous oaks. On the other hand, deciduous oak pollen grains have relatively uniform sculpturing, with only two types encountered: scabrate-verrucate and rugulate sculpturing. This sculpturing is mainly present in deciduous oaks, despite its occurrence in some evergreen oaks. An absolute discrimination between evergreen and deciduous oak pollen is thus impossible and would require additional evidence in the form of macrofossils. The diagnostic criteria are applied to a Miocene pollen assemblage from Zhejiang Province, eastern China and demonstrate the high diversity of fossil oaks in the vegetation. The fossil pollen includes three morphotaxa of deciduous origin, two morphotaxa of evergreen habit, and three oaks whose habit is uncertain.
5

The Confucian Revival as “Bloodline Memory”: Transmitting a Lineage Tradition in Contemporary Huizhou, China

Liu, Wei 07 September 2022 (has links)
No description available.
6

以專利衡量研發創新投入之資源錯置問題 -以中國東部沿海地區製造業廠商為例 / Misallocation of R&D Inputs by Using Patent Value Index - A Case of the Manufacturing Companies Located in Eastern China

李姵儀 Unknown Date (has links)
專利和創新是近年產業發展極重要的趨勢,但是在過去對於中國產業的資源錯置相關研究中,卻沒有發現以專利來做為衡量產出的標準。因此本研究蒐集了中國2005到2007年的水準以上製造業廠商資料,並將Mtrends專利檢索平台資料庫中之專利資料加以整合,建構出中國水準以上製造業廠商之美國專利資料的資料庫。並依據文獻所提出之資源錯置模型,以資料庫中之專利資料作為創新研發產出之代表,計算出廠商之效率值與資源錯置的程度。根據廠商之專利數量及專利價值指標兩種衡量方式來討論中國東部沿海三大經濟區,環渤海經濟區、長三角經濟區及珠三角經濟區之效率值及資源錯置問題。研究結果發現珠三角經濟區因開放年代較早,在人力及知識累積下,研發效率值相對較高,資源錯置問題亦相對較不嚴重的,而長三角與環渤海經濟區由於產業多集中於高科技產業,部分廠商之技術尚未成熟,因此在研發效率值的表現上較為落後且資源錯置問題亦相對較為嚴重。 / Innovation and patent applications have become the central issue for the industrial development nowadays. In the past, there’s little research to measure the innovation outputs by patents. Thus, in this paper, I collected the data for the manufacturing firms in China from 2005 to 2007 and combine with the patent data in Mtrends database. Based on my misallocation computation, I use patent as the R&D output and measure the innovation efficiency and the misallocation level. Based on my result, the efficiency is higher in Pearl River Delta Economic Zone due to its earlier development and low in Bohai Bay Economic Zone & Yangtze River Delta Economic Zone because of industrial concentration. Thus, the misallocation is much more severe in Bohai Bay Economic Zone & Yangtze River Delta Economic Zone and is much lighter in Pearl River Delta Economic Zone.
7

Water content and H-O-Li isotopes in lower crustal granulite minerals / Teneurs en eau et compositions isotopiques de H, O et Li des minéraux des granulites de la croûte continentale inférieure de l'Est de la Chine

Yang, XiaoZhi 03 July 2008 (has links)
Pour la première fois, une étude par spectroscopie infrarouge à transformée de Fourrier et par microsonde ionique des minéraux majeurs de la croûte inférieure et des péridotites mantelliques a été entreprise afin de mieux caractériser les mécanismes d’incorporation et les teneurs en eau de ces minéraux nominalement anhydres, et de déterminer leurs compostions isotopiques en H, O, et Li pour retracer les échanges latéraux et horizontaux de l’eau dans la lithosphère continentale profonde. Les résultats montrent que: (1) Les minéraux nominalement anhydres, comme les pyroxènes et plagioclase, dans les granulites de la croûte inférieure contiennent de l’eau en trace essentiellement sous forme hydroxyles et accessoirement sous forme moléculaire, avec des concentrations (exprimées en poids H2O) allant de 200 à 2330 ppm pour les clinopyroxènes, de 60 à 1875 ppm pour les orthopyroxènes, de 65 à 900 ppm pour les plagioclases. Les teneurs calculées pour chaque roche totale d’après sa composition minéralogique et la teneur en eau des minéraux varient de 155 à 1100 ppm. (2) Les teneurs en H2O des minéraux majeurs et en roche totale de la croûte continentale inférieure sont manifestement plus élevées que celles du manteau lithosphérique sous-jacent, suggérant des variations verticales de la quantité d’H2O dans la lithosphère continentale profonde. Un tel contraste peut affecter de façon notable le comportement rhéologique de la lithosphère continentale. (3) Les rapports isotopiques de l’oxygène des pyroxènes étudiés, et probablement les roches totales, exprimés en [delta]18OSMOW , vont de ~ 4,5 à 12,5‰. Ceci indique la contribution de matériaux recyclés de la croûte continentale durant la pétrogenèse des échantillons ayant un TM18O élevé. (4) Les minéraux de la granulites sont caractérisés par des valeurs de élevées TMD, avec des valeurs de -80~-10‰ exprimées en [delta]DSMOW; les minéraux sont le plus souvent en équilibre les uns avec les autres lorsque l’on considère leurs compositions isotopiques moyennes. (5) Les compositions isotopiques du Lithium mesurée dans les minéraux de nos échantillons de granulites, exprimées en [delta]7Li par rapport à Lsvec, varient de -13 à +4.7 ‰. Ces valeurs sont donc pour la plus part inférieures à celles mesurées sur les MORB (2 – 6‰). La dispersion des valeurs reflètent l’hétérogénéité de la source des granulites, et les valeurs bassent resultent probablement de la perte par diffusion de Li pendant la mise en place des liquides silicatées provenant du manteau dans la croûte inférieure. (6) La grande hétérogénéité des teneurs en eau et en Lithium, et des compositions isotopiques de H-O-Li indique l’absence de circulation de fluide pervasive au travers de la croûte inférieure, qui aurait pour effet de supprimer les hétérogénéités à petite échelle et de les diminuer fortement à grande échelle / For the first time, systematic investigations of water content and H-O-Li isotopic compositions of minerals in lower crustal granulites, as well as water content of minerals in mantle peridotites, from eastern China have been carried out by Fourier transform infrared spectrometer and ion microprobe. The results show that: (1) Nominally anhydrous minerals, such as pyroxenes and plagioclase, in the lower crust generally contain trace amounts of structural water, with their content (H2O by wt.) varying from 200 to 2330 ppm for clinopyroxene, 60 to 1875 ppm for orthopyroxene, 65 to 900 ppm for plagioclase and 155 to 1100 ppm for the estimated bulk compositions. (2) Water contents of minerals in lower crustal granulites from eastern China, and their bulk values, are significantly higher than those in the underlying upper mantle, implying vertical heterogeneities of water distribution in the deep continental lithosphere; the contrast in water content even affect the rheological strength of the lithosphere. (3) The O-isotopic compositions of pyroxenes in the lower crustal granulites from eastern China are highly variable between different localities (~ 4.5 to 12.5‰, expressed in [delta]18OSMOW values), indicating variable influences from recycled crustal materials on their protoliths. (4) The H-isotopic compositions of granulite minerals from eastern China, are mostly in the range of -80 to -10‰ expressed in [delta]DSMOW values, and these minerals are usually in equilibrium with their [delta]D values. The relatively high [delta]D of granulite minerals may be related with degassing loss of H during the genesis of granulites. (5) The Li-isotopic compositions of granulite minerals from eastern China are usually in the range of -13 to 4.7‰, mostly lower than those of MORB (2-6‰). They reflect the source heterogeneity and are probably results of high-T Li diffusion during the intrusion of their original melts into the preexisting lower crust. (6) The large dispersion of Li and water contents and of H-O-Li isotopic results indicate the absence of any pervasive fluids in the lower crust

Page generated in 0.0875 seconds