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排序方式： 共有488条查询结果，搜索用时 15 毫秒
131.
Jianwei Zhou 《Czechoslovak Mathematical Journal》2006,56(2):721-732
This paper studies the relationship between the sections and the Chern or Pontrjagin classes of a vector bundle by the theory
of connection. Our results are natural generalizations of the Gauss-Bonnet Theorem. 相似文献
132.
PHILIP T. GILES 《The Canadian geographer》2002,46(1):6-16
Sea levels are rising throughout the Atlantic Provinces at present and this is expected to continue throughout this century, forcing general coastline retreat and adjustment. In this study, a part of the coastline of eastern Prince Edward Island is examined for changes during historical time (1784–1994) using maps and aerial photography. MacVanes Pond is located between Basin Head Harbour and South Lake, all three of which were once lagoons connected to the same tidal circulation system. Sand barrier retreat has closed the connection to Basin Head Harbour and it is now a separate body of water. Meanwhile, the location of a tidal inlet at MacVanes Pond has been strongly influenced by longshore drift and the inlet has closed, re‐opened to the northeast, and subsequently shifted to the southwest. Human activities in the area have previously been, and will continue to be, affected by sea level rise and transgression. Actuellement, le niveau de la mer s'élève dans la région des provinces de l'Atlantique et l'on prévoit que cette tendance se maintiendra tout au long du présent siècle, ce qui aura pour effet général de faire reculer le littoral et de le modifier. La présente étude examine une partie du littoral est de l'Île‐du‐Prince‐Édouard pour y déceler des changements qui se sont produits dans le temps (1784–1994) à partir de cartes et de photographies aériennes. L'étang MacVanes est situé entre le bassin Head‐Harbour et le lac South, trois plans d'eau qui étaient autrefois des lagunes reliées au même système de marée. Or, une barre de sable a fermé le lion avec le bassin Head‐Harbour, qui est maintenant une masse d'eau distincte. Entre‐temps, l'emplacement d'un goulet de marée à l'étang MacVanes a été grandement influencé par la dérive littorale, au point de se fermer pour se frayer une nouvelle ouverture au nord‐est et par la suite au sud‐ouest. Les activités humaines de cette région ont été affectées, et continueront de l'être, par l'élévation du niveau de la mer et sa transgression. 相似文献
133.
M. D. Watts 《Australian Journal of Earth Sciences》2013,60(3):229-234
An intense Bouguer anomaly ‘high’ of about 30 milligals amplitude has been delineated to the east of Cootamundra, New South Wales. It is correlated with a north‐trending belt of basic metamorphic rocks of probable Upper Silurian age. The subsurface shape of the belt is deduced by qualitative and quantitative analytical techniques applied to the gravity data; it is inferred that the boundary on the western side is near‐vertical, while that on the eastern side is believed to have been overthrust by the Middle Devonian Young Granite. It appears also that there are no horizontal density variations below a depth of 6–7 km, implying that the base of the Young Granite lies at about this depth. 相似文献
134.
Paul Forman 《Berichte zur Wissenschaftsgeschichte》2010,33(2):157-175
(An)erkennung der Postmodernität: Hilfen für Historiker – und Historiker der Wissenschaften im Besonderen. Ausgehend von einer Unterscheidung zwischen der Postmodernit?t als einer von der Modernit?t durch eine breite Umkehr ihrer kulturellen Grundannahmen abgegrenzten historischen Ära und dem Postmodernismus – einer von den selbsternannten Postmodernisten in der frühen Postmodernität angenommenen intellektuellen Attitüde – thematisiert der Aufsatz zwei grundsätzliche Charakteristika der Postmodernität: Erstens die Umkehrung der kulturellen Rangfolge von Wissenschaft und Technik, worin Postmodernität und Postmodernismus übereinstimmen. Zweitens die Ablösung des Ideals eines methodisch vorgehenden, uneigennützigen Wissenschaftlers, nicht durch ein fragmentiertes Subjekt, wie der Postmodernismus behauptet, sondern durch den einseitig interessierten Unternehmer, welcher unter Missachtung aller Regeln hartnäckig seine Eigeninteressen verfolgt. Diese Umkehr in Bedeutung und Rolle von Wissenschaft und Technologie, die um 1980 begann, ist ein Kennzeichen des Übergangs von der Modernit?t zur Postmodernität. Diese Umkehr ist primär zu erkennen als eine Ablehnung des Regelhaften, des methodischen Vorgehens – mit dem “Methodismus” als einer die Modernität auszeichnenden kulturellen Perspektive – aber auch als eine Ablehnung der Uneigennützigkeit, einer in der Modernität besonders wert geschätzten Geisteshaltung. Postmodernität konstituiert sich somit als diese Umwertung der Werte, die ihre Quelle im ich‐fixierten, transgressiven und “risiko”‐freudigen postmodernen Individuum und seinen anti‐sozialen Annahmen in Bezug auf Persönlichkeit hat. In der Wissenschaftsgeschichte selbst findet sich daher seit circa 1980 ein entsprechender Wandel der wissenschaftlichen Aufmerksamkeit weg von der Wissenschaft und hin zur Technologie. Damit einhergeht eine erstaunliche Vermeidung sozialhistorischer Perspektivierung, wie sie sich nicht zuletzt in der Abkehr von kausalistischen “Einfluss”‐Erklärungen zugunsten voluntaristischer “Ressourcen”‐Erklärungen spiegelt. (Re)cognizing Postmodernity: Helps for Historians – of Science Especially. stmodernity, a historical era demarcated from modernity by a broad reversal in cultural presuppositions, is distinguished from postmodernism, an intellectual posture adopted by self‐identified postmodernists early in postmodernity. Two principal features of postmodernity are addressed: first, the downgrading of science and the upgrading of technology in cultural rank – on which postmodernity and postmodernism are in accord; second, the displacement of the methodical, disinterested scientist, modernity's beau ideal, not by a fragmented subject as postmodernism claims, but by the single‐minded entrepreneur, resourcefully pursuing his self‐interest in disregard of all rules. The reversal in rank and role as between science and technology, setting in circa 1980, is a marker of the transition from modernity to postmodernity. That reversal is to be cognized primarily as rejection of rule‐following, of proceeding methodically – ‘methodism’ being the cultural perspective that uniquely distinguished modernity – but also as rejection of disinterestedness, the quality of mind especially highly esteemed in modernity. Postmodernity is constituted by this transvaluation of values, whose well‐spring is the egocentric, transgressive (hence ‘risk taking’), postmodern personality and its anti‐social presumptions regarding personhood. Within the history of science itself there has been since circa 1980 a corresponding turn of scholarly attention away from science to technology, and a growing distaste for social perspectives, reflected, i. a., in the rejection of causalist ‘influence’ explanations in favor of voluntarist ‘resource’ explanations. 相似文献
135.
Julie Cidell 《Social & Cultural Geography》2014,15(5):571-583
Running is a unique form of mobility because while it involves traveling over distance, it is not usually done as a means of transportation. Although running can and does take place almost anywhere, bringing together hundreds or thousands of runners at a time via an event known as a road race enables a different, transgressive occupation of space that no one runner could accomplish on his or her own. In this paper, based on participant observation, I argue that the transgressive but sanctioned nature of the mobilities that road races allow, by temporarily taking over a space devoted to motorized vehicles and turning it into a space for pedestrians, defines these events as unique moments that are only possible through the collective nature of this usually solitary form of mobility and that allow for the pleasure of being transgressive without the risks that transgression normally entails. The paper further argues for considering ‘event mobilities’ as more than traveling in order to participate in an event, because some kinds of mobility are only possible in the context of an event. 相似文献
136.
《Geological Journal》2017,52(5):768-783
Detailed facies architecture study of the Late Cretaceous (Cenomanian) Nimar Sandstone (Bagh Group), from Son‐Narmada rift valley, Central India, reveals deposition in a fluvial–marine environment. The lower part of the Nimar Sandstone succession depicts deposition in predominantly fluvial setting, whereas the middle–upper part of the succession manifests sedimentation under a tide‐dominated estuarine to a tide–wave influenced shoreface environment. Retrogradational nature of the successions in the upper part and lateral facies change from west to east signifies an eastwardly decreasing marine influence. This attests to a sustained event of marine transgression from the west affecting the Son‐Narmada rift valley during the Late Cretaceous time. Beds with various soft‐sediment deformation structures (SSDS), viz., convolute laminae, load and flame structures, pseudonodules, contorted beddings, syn‐sedimentary faults, and sand/silt dykes, occur in distinct stratigraphic levels within the middle part of the succession. These beds are separated by thick successions of undeformed beds. This paper reports these beds as seismites for the first time from the Son‐Narmada rift valley. The seismites signify instantaneous liquefaction and fluidization of unconsolidated sediments triggered by passage of repetitive earthquake shock waves during sedimentation in fault‐bound rift basin. These seismites are important as they mark a new phase of reactivation of the Son‐Narmada South Fault within the Son‐Narmada rift valley during the Cenomanian time. This reactivation of the Son‐Narmada South Fault led to basinal subsidence under prevalent extensional tectonism, which controlled the sedimentation during the Late Cretaceous time. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
137.
The gene effects of Cicer reticulatum on both double‐podding as qualitative traits and yield criteria as quantitative traits in interspecific hybridization with cultivated chickpea (Cicer arietinum) have not yet been elucidated, despite the easy acquisition of hybrid progeny between two species. This study sought to answer three questions concerning qualitative and quantitative traits in reciprocal crosses between C. arietinum and C. reticulatum. (i) Is there a similarity in the gene effects of flower colour, pigmentation and double‐podded traits in reciprocal interspecific crosses? (ii) What are the expressivity and penetrance of the double‐podded trait in interspecific crosses? (iii) Which heterosis predicts the occurrence and the extent of transgressive variation? The materials for this study were F1, F2 and F3 progeny derived from a reciprocal cross between C. arietinum and C. reticulatum. As qualitative traits, purple flower colour, pigmentation and single‐podded traits in C. reticulatum were governed by a dominant single gene. Purple flower colour and pigmentation were detected to be linked traits as all progeny had the same phenotypes. As quantitative traits, yield criteria in progeny which were double‐podded had higher values than the single‐podded counterparts. Expressivity and penetrance of the double‐podding trait were superior in progeny derived from C. reticulatum × C. arietinum. The results showed that fruitful heterosis was more useful than residual heterosis in F3 as residual heterosis was mostly negative and fruitful heterosis was suggested in self‐pollinated species such as chickpea that lacks inbreeding depression. Interspecific transgression was significant with respect to chickpea improvement because it represented a potential source of novel genetic variation. 相似文献
138.
The Domingos Petrolini Swamp, located on the Southern Coastal Plain of Rio Grande do Sul, near the town of Rio Grande, constitutes an ample holocene lagoonal deposit. Events related to the holocene transgression and their diverse phases of glacial-eustatic ocillations were found through palynological analysis. Bases on these palynological data, four distinct phases to the paleoenvironmental evolution of the ecosystem were identified. It has also shown a transgressive restricted marine sequence on the base , which suggests the existence of a coastal brackish lagoon or a marisme type of environment. Later, there was a gradation for continentality conditions along with a scarce pollinical record. The third phase is characterized by the presence of marine components and halophyte vegetation, showing another transgressive event in that place. Lastly, the end of direct marine influence over the swamp was recorded and also the vegetation development as it appears these days. 相似文献
139.
大学生违法犯罪的心理特征及预防措施 总被引：1，自引：0，他引：1
孙玉文 《大连民族学院学报》2005,7(3):92-93
大学生违法犯罪是一个社会问题,已引起社会的普遍关注．大学生违法犯罪与其特定阶段的心理素质有关．通过分析大学生违法犯罪的心理特征,提出预防措施,以预防和减少大学生违法犯罪行为． 相似文献
140.
Lode Lauwaert 《Journal of the British Society for Phenomenology》2020,51(3):187-200
ABSTRACT The literary oeuvre of Marquis de Sade (1740–1814) has attracted a great deal of interest over the past 200 years, not only from writers, but also from numerous leading philosophers. Among them is Georges Bataille, who particularly emphasizes the apathetic character of the Sadean libertines, meaning that they feel nothing at all. More specifically, the French philosopher focuses on their apathetic enjoyment that goes hand in hand with the abuse of victims. The goal of this article is to clarify that peculiar pleasure by comparing it, among other things, with stoicism and mysticism. It will be shown that in the Sadean universe not moral transgression is central, but rather the transgression of a metaphysical boundary, i.e. the boundary between the human and non-human. 相似文献
