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71.
Igor Koudriavtsev Valentin Dergachev Yury Nagovitsyn Maxim Ogurtsov Högne Jungner 《Geochronometria》2014,41(3):216-222
Radiocarbon 14C is a cosmogenic isotope, which is most extensively used by scientists from a wide variety of fields. Its rate of generation in the atmosphere depends on solar modulation and thus, studying 14C concentration in natural archives, one can reconstruct solar activity level in the past. The paper shows results of box-model calculations of generation of the 14C isotope in the atmosphere and its relative abundance during the time interval 1389–1800 AD, taking into account influence of changing climate. This interval includes the deep minimum of solar activity and period of significant change in atmospheric concentration of CO2 and global temperature. The performed analysis showed that concentration of 14C in the atmosphere reflects not only variations of the galactic cosmic rays intensity but as well changes of temperature and atmospheric CO2 concentration. It is shown that the decrease in CO2 concentration in the atmosphere during 1550–1600 can be connected with absorption of CO2 by the ocean surface layer. Thus, taking into account the climatic changes is an important condition for the reconstruction of solar activity in the past using data based on cosmogenic isotopes. 相似文献
72.
This paper aims to show how young people in former East Germany respond to the globalising processes that are part of the transformation of their society from a state-socialist to a capitalist one. It focuses particularly on the differential ways in which young people perform their identities as global/local subjects through the uses that they make of urban space. While emphasising the agency of young people, the paper seeks to examine the dialectic between globalising forces that are largely beyond their control and the negotiation of these forces in everyday practices of identity-formation. Conceptually, the paper draws particularly on the work of Beck (2000), Beck and Gernsheim (2002) and Giddens (1994) in order to conceptualise the connections between globalisation and individualisation, as well as on feminist and recent geographical work on performativity (Butler, 1990, 1993; Rose, 1996; Gregson and Rose, 2000; Thrift, 1996; Dewsbury, 2000; Dewsbury and Naylor, 2002) in order to gain an embodied understanding of the ways in which individuals construct themselves as global/local subjects. 相似文献
73.
Christine Meyer Björn Sautter Stefan Wolf 《Standort - Zeitschrift für angewandte Geographie》2006,30(2):92-93
Ohne Zusammenfassung 相似文献
74.
The head capsules of chironomids (Insecta: Diptera) are well preserved in sediments and can be recognised to a high taxonomic level, usually genus and sometimes species. Work on lake sediments has shown that they can be accurate indicators of water temperature, oxygen regimes, and nutrient status (particularly total phosphorus and chlorophyll-a), as well as heavy metal pollution. No systematic chironomid analyses, however, have previously been undertaken on archaeological deposits. In order to address this we assessed the use of chironomids in three types of archaeological deposit; firstly, a lake core at the edge of a lake settlement (crannog), secondly, a palaeochannel infill adjacent to a multi-period settlement site and lastly, a Roman well deposit from a floodplain environment. The chironomid assemblages are shown to vary significantly both between and within the sites and reflect the immediate environment and the adjacent area. The lake sediment assemblage reflects the construction of the crannog through elevated levels of organic detritus, wood and woody debris. The palaeochannel assemblage reveals changing natural conditions and nutrient enrichment probably associated with settlement during the Saxon period. The well assemblage is taxonomically restricted and indicative of organic debris, dead plant material, animal dung and possibly human effluent deposited after abandonment of the well. Dry storage of the palaeochannel and well sediments for several years did not appear to affect the concentration or state of preservation of the head capsules. The chironomid reconstructions are shown to provide an additional indicator of human activity which has the potential to provide quantitative data on the character of aquatic environments associated with archaeological sites. 相似文献
75.
Tobias Gössling 《European Planning Studies》2004,12(5):675-689
Network interaction is embedded in social settings, which allows for the development of trust. Trust is supposed to be an efficient functional equivalent of contracts, guarantees, insurances, safeguards, etc. Trust between actors reduces transaction costs. However, trust cannot be introduced and enforced within interaction relationships. It is argued that trust is more likely to occur and to be prevalent when actors have the spatial capability for personal, direct interaction. Thus, proximity and trust are supposed to be positively related to each other. Proximity is strongly interrelated with embeddedness. In the discussion about morality in organisations, there is an assumption we referred to as the 'moral spill-over effect': it is impossible, it is said, to restrict moral competencies and moral behaviour to one particular situation, environment, or topic. However, we argue that, even though trust is a term that is described in moral theory, trust and morality are not necessarily positively correlated. This means that even if embeddedness and proximity in a network lead to an increase of trust between network partners, it does not necessarily produce moral spill-over effects. Thus, proximity and morality do not necessarily have to be positively correlated with each other. The influence of proximity on morality can be positive or negative, depending on the social surrounding in which network collaboration is embedded. 相似文献
76.
77.
Die Consultingbranche bietet für
Geographinnen und Geographen ein breites und interessantes
Betätigungsfeld. Dieses Berufsfeld kann bereits durch
universitäre Veranstaltungen für Studierende erschlossen werden.
Um Einblicke in das Tätigkeitsfeld, die Anforderungen und
Qualifikationsprofile eines Beraters zu geben, bieten sich
Projektseminare an, die in Kooperation mit der Hochschule und
Berufspraktikern durchgeführt werden. 相似文献
78.
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80.
Geodateninfrastrukturen sollen den Zugang zu und die Nutzung von Geoinformationen besser und effektiver gestalten und dadurch
den einen Markt für Geoinformationen etablieren, in dem sowohl Massendaten, wie auch spezielle Informationen im Sinne problemspezifischer
Auskünfte nachgefragt und im Idealfall auch abgerechnet werden k?nnen. Auf verschiedenen Organisationsstufen und in unterschiedlichen
fachlichen Zusammenh?ngen werden zur Zeit internetbasierte Geodateninfrastrukturen (GDI) aufgebaut. Sie orientieren sich an
den internationalen Standards des Open GIS Consortium (OGC) und der Internationalen Standardisierungsorganisation (ISO). Eine
wichtige Voraussetzung für das Gelingen der Initiativen ist, da? sie nicht nur Top-Down von staatlichen Instanzen eingerichtet
und betrieben werden, sondern auch Elemente kooperierender Bottom-Up-Entwicklung enthalten und vor allem alle potentiellen
Nutzer einer GDI, von Datenanbietern über -veredlern und Software-Herstellern bis hin zu Endkunden, einbeziehen. Der Beitrag
stellt den aktuellen Stand der Entwicklung und wichtige aktuelle Beispiele in der Praxis dar. 相似文献