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  2. X-ray absorption fine structure - Wikipedia

    en.wikipedia.org/wiki/X-ray_absorption_fine...

    The atomic X-ray absorption spectrum (XAS) of a core-level in an absorbing atom is separated into states in the discrete part of the spectrum called "bounds final states" or "Rydberg states" below the ionization potential (IP) and "states in the continuum" part of the spectrum above the ionization potential due to excitations of the photoelectron in the vacuum.

  3. List of chaotic maps - Wikipedia

    en.wikipedia.org/wiki/List_of_chaotic_maps

    In mathematics, a chaotic map is a map (an evolution function) that exhibits some sort of chaotic behavior. Maps may be parameterized by a discrete-time or a continuous-time parameter. Maps may be parameterized by a discrete-time or a continuous-time parameter.

  4. Diffraction topography - Wikipedia

    en.wikipedia.org/wiki/Diffraction_topography

    X-ray diffraction topography is one variant of X-ray imaging, making use of diffraction contrast rather than absorption contrast which is usually used in radiography and computed tomography (CT). Topography is exploited to a lesser extent with neutrons , and is the same concept as dark field imaging in an electron microscope .

  5. Discrete spectrum (mathematics) - Wikipedia

    en.wikipedia.org/wiki/Discrete_spectrum...

    A point in the spectrum of a closed linear operator: in the Banach space with domain is said to belong to discrete spectrum of if the following two conditions are satisfied: [1] λ {\displaystyle \lambda } is an isolated point in σ ( A ) {\displaystyle \sigma (A)} ;

  6. Electromagnetic spectrum - Wikipedia

    en.wikipedia.org/wiki/Electromagnetic_spectrum

    In frequency (and thus energy), UV rays sit between the violet end of the visible spectrum and the X-ray range. The UV wavelength spectrum ranges from 399 nm to 10 nm and is divided into 3 sections: UVA, UVB, and UVC. UV is the lowest energy range energetic enough to ionize atoms, separating electrons from them, and thus causing chemical reactions.

  7. Wavelength-dispersive X-ray spectroscopy - Wikipedia

    en.wikipedia.org/wiki/Wavelength-dispersive_X...

    Wavelength-dispersive X-ray spectroscopy (WDXS or WDS) is a non-destructive analysis technique used to obtain elemental information about a range of materials by measuring characteristic x-rays within a small wavelength range. The technique generates a spectrum in which the peaks correspond to specific x-ray lines and elements can be easily ...

  8. X-ray emission spectroscopy - Wikipedia

    en.wikipedia.org/wiki/X-ray_emission_spectroscopy

    X-ray emission spectroscopy (XES) is a form of X-ray spectroscopy in which a core electron is excited by an incident X-ray photon and then this excited state decays by emitting an X-ray photon to fill the core hole. The energy of the emitted photon is the energy difference between the involved electronic levels.

  9. Spectrum (functional analysis) - Wikipedia

    en.wikipedia.org/wiki/Spectrum_(functional_analysis)

    The discrete spectrum is defined as the set of normal eigenvalues or, equivalently, as the set of isolated points of the spectrum such that the corresponding Riesz projector is of finite rank. As such, the discrete spectrum is a strict subset of the point spectrum, i.e., σ d ( T ) ⊂ σ p ( T ) . {\displaystyle \sigma _{d}(T)\subset \sigma ...