Matches in SemOpenAlex for { <https://semopenalex.org/work/W1566223399> ?p ?o ?g. }
Showing items 1 to 97 of
97
with 100 items per page.
- W1566223399 abstract "The absorption of light is an important phenomenon which has many applications in all the natural sciences. One can say that all the chemical elements, molecules, complex substances, and even galaxies, have their own “fingerprint” in the light absorption spectrum, as a consequence of the allowed transitions between all electronic and vibronic levels. The UV-Visible (UV-Vis) light (200-800 nm) has an energy comparable to that typical of the transitions between the electrons in the outer shells or in molecular orbitals. Each atom has a fixed number of atomic levels, and therefore those spectra are composed of narrow lines, corresponding to the transitions between these levels. When molecules and macromolecules are considered, the absorption spectrum is no longer characterised by thin lines but by wide absorption bands. This is due to the fact that the electronic levels are split in many vibrational and rotational sub-levels, which increase in number with the increasing complexity of the molecules. IR spectroscopy is often used to investigate these lower energy modes, but for very complex biological molecules not even this technique can resolve each line precisely because the energy split between the various levels is too small. One possible way to obtain higher resolution spectra is to lower the sample temperature, in order to suppress many of the vibrational and rotational modes. For biological molecules, though, lowering the temperature can be a problem if one wants to study, for example, the activity of enzimes, which only work at physiological temperatures. One of the advantages of absorption spectroscopy (IR and UV-Vis) is to be a non-disruptive technique, also for “delicate” molecules like polymers and biomolecules. In the process of light absorption by molecules, once a photon with the right energy is absorbed, the molecule goes into an excited state at higher energy [Born and Wolf 1999, Dunning & Hulet 1996]. Eventually, it spontaneously returns to the ground state, but it can relax following several mechanisms. When excited, the molecule reaches, in general, one of the sub-levels of a higher electronic state. The first process is then, generally, a relaxation to the lower energy state of that electronic level (schematised in figure 1). This process is usually very fast (in the femtosecond scale) and not radiative. From this level, there are several pathways to dissipate the energy: a radiative transition from the lower level of the excited state to the ground state (fluorescence), accompanied by the emission of a photon at lower energy than the absorbed one; a flip of the electronic spin, which leads to a transition between singlet and triplet state (intersystem crossing), often associated with another" @default.
- W1566223399 created "2016-06-24" @default.
- W1566223399 creator A5010214650 @default.
- W1566223399 creator A5080121800 @default.
- W1566223399 date "2010-01-01" @default.
- W1566223399 modified "2023-10-03" @default.
- W1566223399 title "Nonlinear Absorption of Light in Materials with Long-lived Excited States" @default.
- W1566223399 cites W1592810426 @default.
- W1566223399 cites W1640069878 @default.
- W1566223399 cites W182366568 @default.
- W1566223399 cites W1964599718 @default.
- W1566223399 cites W1965790261 @default.
- W1566223399 cites W1975164617 @default.
- W1566223399 cites W1977780320 @default.
- W1566223399 cites W1982567703 @default.
- W1566223399 cites W1987009243 @default.
- W1566223399 cites W1997543790 @default.
- W1566223399 cites W1997604219 @default.
- W1566223399 cites W2009179128 @default.
- W1566223399 cites W2009693355 @default.
- W1566223399 cites W2018953469 @default.
- W1566223399 cites W2020357856 @default.
- W1566223399 cites W2028258207 @default.
- W1566223399 cites W2030305267 @default.
- W1566223399 cites W2045582639 @default.
- W1566223399 cites W2049299684 @default.
- W1566223399 cites W2060364930 @default.
- W1566223399 cites W2061410319 @default.
- W1566223399 cites W2067030327 @default.
- W1566223399 cites W2067704587 @default.
- W1566223399 cites W2076299972 @default.
- W1566223399 cites W2076755451 @default.
- W1566223399 cites W2082288272 @default.
- W1566223399 cites W2082441764 @default.
- W1566223399 cites W2086141881 @default.
- W1566223399 cites W2088217820 @default.
- W1566223399 cites W2089117476 @default.
- W1566223399 cites W2096691349 @default.
- W1566223399 cites W2110000428 @default.
- W1566223399 cites W2127513824 @default.
- W1566223399 cites W2131952125 @default.
- W1566223399 cites W2145918160 @default.
- W1566223399 cites W2156277680 @default.
- W1566223399 cites W2158047084 @default.
- W1566223399 cites W2158900663 @default.
- W1566223399 cites W2314396495 @default.
- W1566223399 cites W252316601 @default.
- W1566223399 cites W2604936972 @default.
- W1566223399 cites W3021205475 @default.
- W1566223399 cites W3103881532 @default.
- W1566223399 cites W624978279 @default.
- W1566223399 cites W2003500486 @default.
- W1566223399 cites W2311781763 @default.
- W1566223399 doi "https://doi.org/10.5772/6942" @default.
- W1566223399 hasPublicationYear "2010" @default.
- W1566223399 type Work @default.
- W1566223399 sameAs 1566223399 @default.
- W1566223399 citedByCount "1" @default.
- W1566223399 countsByYear W15662233992023 @default.
- W1566223399 crossrefType "book-chapter" @default.
- W1566223399 hasAuthorship W1566223399A5010214650 @default.
- W1566223399 hasAuthorship W1566223399A5080121800 @default.
- W1566223399 hasBestOaLocation W15662233991 @default.
- W1566223399 hasConcept C120665830 @default.
- W1566223399 hasConcept C121332964 @default.
- W1566223399 hasConcept C125287762 @default.
- W1566223399 hasConcept C158622935 @default.
- W1566223399 hasConcept C181500209 @default.
- W1566223399 hasConcept C184779094 @default.
- W1566223399 hasConcept C192562407 @default.
- W1566223399 hasConcept C62520636 @default.
- W1566223399 hasConceptScore W1566223399C120665830 @default.
- W1566223399 hasConceptScore W1566223399C121332964 @default.
- W1566223399 hasConceptScore W1566223399C125287762 @default.
- W1566223399 hasConceptScore W1566223399C158622935 @default.
- W1566223399 hasConceptScore W1566223399C181500209 @default.
- W1566223399 hasConceptScore W1566223399C184779094 @default.
- W1566223399 hasConceptScore W1566223399C192562407 @default.
- W1566223399 hasConceptScore W1566223399C62520636 @default.
- W1566223399 hasLocation W15662233991 @default.
- W1566223399 hasLocation W15662233992 @default.
- W1566223399 hasOpenAccess W1566223399 @default.
- W1566223399 hasPrimaryLocation W15662233991 @default.
- W1566223399 hasRelatedWork W1971978554 @default.
- W1566223399 hasRelatedWork W1999781666 @default.
- W1566223399 hasRelatedWork W2027516397 @default.
- W1566223399 hasRelatedWork W2038599716 @default.
- W1566223399 hasRelatedWork W2040546667 @default.
- W1566223399 hasRelatedWork W2055516335 @default.
- W1566223399 hasRelatedWork W2060051479 @default.
- W1566223399 hasRelatedWork W2073966546 @default.
- W1566223399 hasRelatedWork W2086872829 @default.
- W1566223399 hasRelatedWork W3100129032 @default.
- W1566223399 isParatext "false" @default.
- W1566223399 isRetracted "false" @default.
- W1566223399 magId "1566223399" @default.
- W1566223399 workType "book-chapter" @default.