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1	Anatomy and Biomechanics of Peltate Begonia Leaves—Comparative Case Studies Rjosk, Annabell, Neinhuis, Christoph, Lautenschläger, Thea 21 May 2024 (has links) Plants are exposed to various external stresses influencing physiology, anatomy, and morphology. Shape, geometry, and size of shoots and leaves are particularly affected. Among the latter, peltate leaves are not very common and so far, only few studies focused on their properties. In this case study, four Begonia species with different leaf shapes and petiole attachment points were analyzed regarding their leaf morphology, anatomy, and biomechanical properties. One to two plants per species were examined. In all four species, the petiole showed differently sized vascular bundles arranged in a peripheral ring and subepidermal collenchyma. These anatomical characteristics, low leaf dry mass, and low amount of lignified tissue in the petiole point toward turgor pressure as crucial for leaf stability. The petiole-lamina transition zone shows a different organization in leaves with a more central (peltate) and lateral petiole insertion. While in non-peltate leaves simple fiber branching is present, peltate leaves show a more complex reticulate fiber arrangement. Tensile and bending tests revealed similar structural Young’s moduli in all species for intercostal areas and venation, but differences in the petiole. The analysis of the leaves highlights the properties of petiole and the petiole-lamina transition zone that are needed to resist external stresses. info:eu-repo/classification/ddc/580 ddc:580
2	Kleinskalige Magnetfelder der Sonne und ihr Einfluß auf Chromosphäre, Übergangszone und Korona / Small-Scale Solar Magnetic Fields and their Influence upon Chromosphere, Transition Region and Corona Wilken, Volker 28 June 2001 (has links) No description available. 530 Physik Mathematics and Computer Science GCT VTT SUMER SOHO UV/EUV-Teleskop Spektroskopie Polarimetrie seeing Sonne Magnetfeld chromosphärisches Netzwerk Photosphäre Chromosphäre Übergangszone Korona explosive Ereignisse magnetische Flußröhren magnetische Strukturen zweidimensionale Spektropolarimetrie GCT VTT SUMER SOHO UV/EUV Telescope spectroscopy polarimetry seeing sun magnetic field chromospheric network photosphere chromosphere transition region corona explosive events magnetic flux tubes magnetic structures two-dimensional spectro-polarimetry 39.51 TGC 100: Sonnenbeobachtung {Astronomie} TGC 300: Sonnenspektrum {Astronomie} TGC 500: Sonnenaktivität {Astronomie} TGC 740: Sonnenatmosphäre RPV 200: Optische Instrumente {Physik} RPV 260: Fernrohr Teleskop {Physik: Optik} RPV 340: Filter {Physik: Optik} RR 000: Spektroskopie {Physik} TCG 000: Astronomische Optik

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Anatomy and Biomechanics of Peltate Begonia Leaves—Comparative Case Studies

Kleinskalige Magnetfelder der Sonne und ihr Einfluß auf Chromosphäre, Übergangszone und Korona / Small-Scale Solar Magnetic Fields and their Influence upon Chromosphere, Transition Region and Corona