Sökning: "Maria Hellgren"

Hittade 3 avhandlingar innehållade orden Maria Hellgren.

  1. 1. Density Functionals for Dynamic Linear Response in Finite Systems

    Författare :Maria Hellgren; Matematisk fysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : This dissertation investigates a new method for obtaining excited-state properties of finite, many-electron systems such as atoms, molecules and nano-systems. The method combines the merits of many-body perturbation theory and time-dependent perturbation theory and yields approximate density response functions which preserve basic physical conservation laws. LÄS MER

  3. 2. Ethylene and Auxin in the Control of Wood Formation

    Författare :Jenny Maria Hellgren; SLU; []
    Nyckelord :LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; auxin ; ethylene ; lignification ; growth rate ; fibres ; cambium ; gas chromatography ; reaction wood ; organic acids ; mass spectrometry ; populus tremula ; pinus sylvestris; biology; biologi;

    Sammanfattning : This thesis considers aspects of the regulation of growth rate and fibre properties in forest trees. These properties are both genetically determined and influenced by environmental stimuli. Induction of reaction wood is an environmentally induced process involving changes in growth rate and fibre properties that can be readily studied. LÄS MER

  4. 3. Students as scientists : a study of motivation in the science classroom

    Författare :Jenny Maria Hellgren; Magnus Österholm; Jim Ryder; Umeå universitet; []
    Nyckelord :SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; motivation; emotions; experiences; authentic science; student-teacher-scientist partnership; secondary school; implementation; classroom; mathematics; self-determination theory; didactics of natural science; naturvetenskapens didaktik;

    Sammanfattning : School science and mathematics have been criticized for being difficult, de-contextualised and teacher-centred. This thesis concerns student motivation in science and mathematics in secondary school, and in particular student motivation in relation to student-teacher-scientist partnerships (STSPs) and an authentic science task called the Medicine Hunt where students help scientists to find new antibiotics. LÄS MER