Sökning: "carbon compounds"

Visar resultat 1 - 5 av 426 avhandlingar innehållade orden carbon compounds.

  1. 1. Lowcoordinated Silicon and Hypercoordinated Carbon : Structure and Stability of Silicon Analogs of Alkenes and Carbon Analogs of Silicates

    Författare :Anders M. Eklöf; Henrik Ottosson; Sten Lunell; Thomas Müller; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; silenes; zwitterionic silenes; silenolates; reverse polarization; natural resonance theory; hypervalent carbon; hypercoordinated carbon; thermolysis; lowcoordinated silicon; Organic chemistry; Organisk kemi;

    Sammanfattning : Quantum chemical studies on lowcoordinated group 14-16 compounds have been performed. This thesis focuses particularly on silenes influenced by reverse Siδ-=Cδ+ bond polarization. Hypercoordinated carbon compounds are also studied. LÄS MER

  2. 2. Carbon-based magnetic nanomaterials

    Författare :Valeria Zagaynova; Tatiana Makarova; Mauro Ricco; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; carbon nanotube; fullerene; single molecular magnet; Mn12; graphite fluoride; nanoporous carbon; molecular magnetism; magnetic properties; SQUID magnetometry; x-ray diffraction; Raman spectroscopy; Materials Science; materialvetenskap;

    Sammanfattning : Magnetism of carbon-based materials is a challenging area for both fundamental research and possible applications. We present studies of low-dimensional carbon-based magnetic systems (fullerene-diluted molecular magnets, carbon nanotubes, graphite fluoride, and nanoporous carbon) by means of SQUID magnetometer, X-ray diffraction and vibrational spectroscopy, the latter techniques used as complementary instruments to find a correlation between the magnetic behaviour and the structure of the samples. LÄS MER

  3. 3. Measuring Elemental Carbon in Occupational Environments

    Författare :Anna Wallén; Hans-Christen Hansson; Göran Lidén; Karine Elihn; Thomas Kuhlbusch; Stockholms universitet; []
    Nyckelord :Diesel Exhaust Particles; Thermo-Optical Analysis; Black Carbon; Pyrolytic Carbon; Wood Smoke Particles; Water Soluble Organic Compounds; Asphalt Paving Work; Bio Fuels; Subway Aerosol; NATURAL SCIENCES; NATURVETENSKAP; Applied Environmental Science; tillämpad miljövetenskap;

    Sammanfattning : Carbonaceous aerosol particles from combustion, such as diesel exhaust particles (DEP), harm human health and affect the Earth’s radiative system.Elemental carbon (EC) has been proposed to be used as a marker of DEP. LÄS MER

  4. 4. Studies of carbon nanomaterials based on fullerenes and carbon nanotubes

    Författare :Agnieszka Iwasiewicz-Wabnig; Bertil Sundqvist; Eleanor E.B. Campbell; Umeå universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; fullerenes; carbon nanotubes; fullerene polymers; intercalation compounds; high pressure; Raman spectroscopy; X-ray diffraction; atomic force microscopy; phase transitions; Material physics with surface physics; Materialfysik med ytfysik;

    Sammanfattning : Materials based on fullerenes and carbon nanotubes are very much different from most “traditional” materials, primarily because they are built from nanosized molecules with highly symmetry-dependent properties. Being the subject of a very active research field over the last twenty years, carbon nanostructures proved to be indeed extraordinary. LÄS MER

  5. 5. On the role of terrestrial ecosystems in a changing Arctic

    Författare :Adrian Gustafson; BECC: Biodiversity and Ecosystem services in a Changing Climate; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Northern high latitudes; Arctic climate change; climate-vegetation feedbacks; shrubs; shrubification; treeline migration; LPJ-GUESS; RCA-GUESS; nitrogen; carbon; Northern high latitudes; Arctic climate change; climate-vegetation feedbacks; shrubs; shrubification; treeline migration; LPJ-GUESS; RCA-GUESS; Nitrogen; Carbon;

    Sammanfattning : The global temperature rise is proportional to the cumulative amount of CO2 emissions to the atmosphere. This observation is consistent between climate models and historical observations. LÄS MER