ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    The European physical journal 202 (1967), S. 38-48 
    ISSN: 1434-601X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract A variational procedure is investigated which leads to solutions that can describe collective modes connected with symmetries of the Hamiltonian in a non-phenomenological way. Starting from a given set of trial ware functions {Φ} all superpositions of the symmetry-transforms of anyΦ are permitted in addition. The trial wave functionsΦ and the weight functions of the superposition are varied simultaneously. The solutions are shown to be eigenfunctions of the symmetry operators. The weight functions are partly determined by group properties. In the case of one-dimensional representations, i.e. especially for Abelian symmetry groups, the superposition degenerates to become a projection. In the limit of a strongly symmetry-violating solutionΦ the energy spectrum is also determined by group properties and the weight function may be interpreted as the wave function of a collective motion. The equations of motion will then describe the interaction between collective and intrinsic modes. The non-axial rotator is considered as an example.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1434-6036
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The dependence of macroscopic systems upon their environment is studied under the assumption that quantum theory is universally valid. In particular scattering of photons and molecules turns out to be essential even in intergalactic space in restricting the observable properties by locally destroying the corresponding phase relations. The remaining coherence determines the ‘classical’ properties of the macroscopic systems. In this way local classical properties have their origin in the nonlocal character of quantum states. The effect of the interaction depends essentially on whether it permanently ‘measures’ discrete or continuous quantities. For discrete variables (here exemplified by two-state systems) the classical properties are given by the measurement basis. The continuous case, studied for translational degrees of freedom, leads to a competition between destruction of coherence by the interaction and dispersion of the wave packet by the internal dynamics. A non-phenomenological Boltzmann-type master equation is derived for the density matrix of the center of mass. Its solutions show that the much-discussed dispersion hardly ever shows up even for small dust particles or large molecules. Instead the coherence length decreases towards the thermal de Broglie wave length of the object, whereas the incoherent spread increases. The Ehrenfest theorems are shown nevertheless to remain valid for recoil-free interactions. Some consequences of these investigations for the quantum theory of measurement are pointed out.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 1434-601X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract From the anomalies in theβ-decays of Pb210 and Bi210, relations between the shell model wave functions of the ground states of Pb210, Bi210 and Po210 are derived. These relations are however not satisfied by wave functions calculated under the assumption of two-body central forces of zero range. We make use of the fact that such forces seem to be a good approximation for even-even-nuclei (in our case Pb and Po), but not for odd-odd-nuclei (Bi in our case), and derive the wave function for the 1− level of Bi210 from the wave functions of Pb210 and Po210 using the relations obtained from theβ-decay anomalies.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Springer
    The European physical journal 175 (1963), S. 490-505 
    ISSN: 1434-601X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The theory of α-decay is reformulated in order to point out the necessary approximations in a rigorous way. The connection between the formulas given byThomas and byMang is easily established.Mang's explicit expressions of reduced widths, valid for shell model wave functions, are brought into a general form. The theory is applied to BCS wave functions and the decay constants of several Po-isotopes are calculated as an example. Furthermore results are presented which favour a spin assignmentI=18 and a predominating (h9/2) 8 2 (i11/2) 10 2 configuration for the Po212 isomeric state. The penetrabilities are calculated numerically, since the WKB-method is found to be unsatisfactory.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    Springer
    The European physical journal 217 (1968), S. 485-509 
    ISSN: 1434-601X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Nuclear formation processes and the conditions of their physical environment are investigated on the basis of the empirical abundance distribution of the nuclei. Three different abundance components of the heavy nuclei require very different physical conditions for their formation but appear genetically correlated. The component formed in a slow neutron capture chain indicates the pre-existence of the neutron-rich component, and of an iron abundance peak considerably smaller than found in the solar system. The neutron-rich and the proton-rich components seem to have been formed byβ-decay from progenitors which were produced at conditions of matter densityρ≈2×1010g/cm3 and of temperaturekT≈500keV, respectively.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    Springer
    The European physical journal 188 (1965), S. 361-373 
    ISSN: 1434-601X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract A variational procedure using trial wave functions projected on to symmetry eigenstates is investigated. In the individual particle model it leads to generalized self-consistent single-particle equations being dependent on the symmetry eigenvalue. A perturbation expansion appropriate for the case of strong symmetry violations is described. Model independent expressions for the moment of inertia and the decoupling parameter are derived by applying the method to rotational symmetry.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    [s.l.] : Nature Publishing Group
    Nature 225 (1970), S. 361-362 
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] Theories of stellar nucleosynthesis3 assume that these s-nuclei have been formed by neutron irradiation of preexisting iroa-peak nuclei as a "seed"4. The empirical abundance distribution, however, indicates a genetic relationship between s and other heavy nuclei abundance components5. This ...
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Journal of Organometallic Chemistry 386 (1990), S. C13-C15 
    ISSN: 0022-328X
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    ISSN: 0022-328X
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Journal of Organometallic Chemistry 386 (1990), S. C13-C15 
    ISSN: 0022-328X
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...