Sökning: "åkermark"

Visar resultat 16 - 20 av 44 avhandlingar innehållade ordet åkermark.

1. 16. Hydrogen Bonded Phenols as Models for Redox-Active Tyrosines in Enzymes

   Författare :Josefin Utas; Björn Åkermark; Helena Grennberg; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; electron transfer; photosystem II; radicals; imidazole; hydrogen bonding; Organic chemistry; Organisk kemi;

   Sammanfattning : This thesis deals with the impact of hydrogen bonding on the properties of phenols. The possibility for tyrosine to form hydrogen bonds to other amino acids has been found to be important for its function as an electron transfer mediator in a number of important redox enzymes. LÄS MER

3. 17. Ruthenium(II) Polypyridyl Complexes in Supramolecular Systems relevant to Artificial Photosynthesis

   Författare :Henriette Wolpher; Björn Åkermark; Licheng Sun; Johannes Vos; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Ruthenium complexes; Organic chemistry; Organisk kemi;

   Sammanfattning : This thesis describes the synthesis and properties of ruthenium complexes relevant to artificial photosynthesis. The work includes preparation of RuIIpolypyridine complexes as well as multi component systems where RuII(bpy)3 or RuII(tpy)2 type complexes are used as photosesnsitizers. LÄS MER

4. 18. Synthesis and Photoinduced Electron Transfer of Donor-Sensitizer-Acceptor Systems

   Författare :Yunhua Xu; Licheng Sun; Björn Åkermark; Jean-Pierre Sauvage; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Artificial photosynthesis; Dye-sensitized solar cells; Electron donors; Dinuclear ruthenium complexes; Electron transfer; Organic chemistry; Organisk kemi;

   Sammanfattning : Artificial systems involving water oxidation and solar cells are promising ways for the conversion of solar energy into fuels and electricity. These systems usually consist of a photosensitizer, an electron donor and / or an electron acceptor. LÄS MER

5. 19. Plant colonization of oak plantations - the interactive effects of local environment and land-use history

   Författare :Karin Valtinat; Biologiska institutionen; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Nitrogen mineralization; Phosphorus; Plant ecology; Växtekologi; Soil acidity; Seed sowing; Dispersal limitation; Species diversity; Indicator species analysis; Functional groups; Succession; Understory vegetation; Land-use history; Temperate forest;

   Sammanfattning : In Europe, only small fragments of deciduous woodlands remain intact and species dependent on this ecosystem have declined. In southern Sweden, a shifting trend during the 20th century, with more afforestations on former arable land, resulted in new oak stands. These new stand are either on former arable fields or on continuously forested land. LÄS MER

7. 20. Plant community assembly during succession from arable fields to semi-natural grassland

   Författare :Barbara Christine Schmid; Biodiversitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; diversity; arable-to-grassland succession; space-for-time approach; land-use history; plant community assembly; grazing management; connectivity measures; dispersal vector; vascular plants; grassland specialist conservation;

   Sammanfattning : Large areas of grazed, species rich semi-natural grassland were lost in Europe during the last two centuries and as a consequence led to decreases in grassland specialist species. Therefore, today the “restoration” of grassland on previously arable fields is recommended for the protection of grassland specialists. LÄS MER