Sökning: "Superposition eye"

Hittade 5 avhandlingar innehållade orden Superposition eye.

  1. 1. Visual ecology of insect superposition eyes

    Författare :Pär A Brännström; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Animal physiology; tiger beetle; hawkmoth; mayfly; insect; visual ecology; eye design; vision; compound eye; Djurfysiologi;

    Sammanfattning : In the superposition compound eye each rhabdom (light sensitive unit) receives light through many ommatidial facets, while in the apposition compound eye every rhabdom receives light from a single facet. The superposition design increases photon capture, which is an advantage in dark environments. LÄS MER

  3. 2. Ommatidial adaptations for vision in nocturnal insects

    Författare :Rikard Frederiksen; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Gain of transduction; Information rate; Signal-to-noise ratio; Apposition eye; Optical sensitivity; Nocturnal insects; Superposition eye; Vision;

    Sammanfattning : Nocturnal vision is a demanding task for insects with small eyes. As it gets dimmer the noise imposed by the stochastic nature of photon arrival makes vision unreliable. Despite this, there are quite a number of animal species that are active at night and apparently see well. LÄS MER

  4. 3. Adaptations for nocturnal vision in insect apposition eyes

    Författare :Birgit Greiner; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; temporal and spatial summation; optical and neural adaptations; theoretical modelling.; Djurs anatomi och morfologi; Zoologi; dim light; vision; landmark navigation; nocturnal bees and wasps; Zoology; Animal anatomy; animal morphology;

    Sammanfattning : Due to our own preference for bright light, we tend to forget that many insects are active in very dim light. The reasons for nocturnal activity are most easily seen in tropical areas of the world, where animals face severe competition for food and nocturnal insects are able to forage in a climate of reduced competition and predation. LÄS MER

  5. 4. Towards single Ce ion detection in a bulk crystal for the development of a single-ion qubit readout scheme

    Författare :Ying Yan; Atomfysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Fysicumarkivet A:2013:Yan; Ultra-violet laser spectroscopy; Single ion detection; Rare-earth-ion-doped crystals; Quantum computing; Laser stabilisation;

    Sammanfattning : The work presented in this thesis was concerned with investigating the relevant spectroscopic properties of Ce ions randomly doped in an Y2SiO5 crystal at low temperatures (around 4 K), in order to develop a technique and an experimental set-up to detect the fluorescence photons emitted by a single Ce ion. The aim of the work was to determine whether a single Ce ion (referred to as the readout ion) can be used as a local probe to sense the quantum state of a neighbouring single-ion qubit via a state-selective interaction between the readout and qubit ion. LÄS MER

  7. 5. Waves and Trajectories in Quantum Dots

    Författare :Tomas Lundberg; Joan Martorell; Linköpings universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : This thesis deals with electron transport in low-dimensional semiconductor nanostructures,and in particular, systems with quasi zero-dimensional properties, called quantum dots. These systems are so small that the electron wavelength is comparable to the size of systems, which means that the wave nature of the electrons is of fundamental importance. LÄS MER