Institut für Physik und Astronomie
Refine
Year of publication
Document Type
- Article (4248) (remove)
Keywords
- stars: massive (56)
- gamma rays: general (45)
- stars: early-type (44)
- stars: winds, outflows (42)
- cosmic rays (39)
- diffusion (39)
- Magellanic Clouds (38)
- radiation mechanisms: non-thermal (38)
- X-rays: stars (37)
- ISM: supernova remnants (34)
Institute
- Institut für Physik und Astronomie (4248)
- Institut für Chemie (16)
- Extern (13)
- Institut für Geowissenschaften (9)
- Department Psychologie (5)
- Institut für Biochemie und Biologie (4)
- Zentrum für Lehrerbildung und Bildungsforschung (ZeLB) (3)
- Institut für Informatik und Computational Science (2)
- Institut für Mathematik (2)
- Department Erziehungswissenschaft (1)
Langmuir-Blodgett(LB) multilayers were prepared from disc-shaped multiyne mesogens based on amphiphilic alkyl pentakis(aryl-ethynyl)benzene ethers. The two compounds used are characterized by five hydrophobic flexible chains and one hydrophilic substituent at the terminal position of the alkoxy chain. The LB films were analysed by X-ray scattering and spectroscopic measurements. An edge-on arrangement of the two discotic pentaalkynes within Y-type bilayers with a different packing density proved to be possible for the LB films of both compounds.
The possibilities and limits of structure refinement of Langmuir-Blodgett films by means of symmetrical reflection of X- rays are described using the example of a stearic acid multilayer. Three different techniques for the determiantion of the electron density profile from reflectivity data are compared; a Fourier method, a Patterson method, and model calculations. The important role of the a priori information for finding the besft structure model is outlined.
Combining issues of "girl-suited" science teaching, STS and constructivism in a physics textbook
(1992)
Zur Ökologisierung des Lernprozesses : Versuch über einen vernachlässigten Aspekt von Umweltbildung
(1993)
Amphiphilic disc-shaped penta-alkynes were studied with regard to their molecular organization in Langmuir-Blod- gett (LB) mono- and multilayers. It was found that each compound investigated forms edge-on arranged stable monolayers at the air-water interface. LB-multilayers derived from fivefold pentyl-substituted pentaynes are characterized by an edge-on ordering of the molecules within Y-type bilayers. One of these compounds, containing a hydoxy substituent as hydrophilic head group, is exemplified and two possible rectangular molecular assemblies perpendicular to the substrate, each with a columnar in-plane packing, will be discussed as a result of molecular modelling. Based on the experimental results, hexagonal layer packing in the LB-film of a disc-shaped penta-alkynyl carboxylic acid without lateral substituents proved to be possible, which, furthermore, could be confirmed by molecular mechanics simulation.
The observation of a new high pressure phase transition in tetramethyl ammonium tetrabromocuprate
(1994)
Study of crosslinking process in fluorinated poly(imide-amide)s containing pendant cyano groups
(1994)
Study of crosslinking process in fluorinated poly(imide-amide)s containing pendant cyano groups
(1994)
Feuchtesensor
(1994)