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
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 64 (1988), S. 1652-1656 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: It is shown that the wave equation ψxx−ψyy=0 for the field ψ(x,y) in the domain R(xy) can be transformed into a wave equation Ψξξ−Ψηη=0 for the field Ψ(ξ,η) in the domain S(ξη). The transformation is accomplished through a complex function F(x,y)=ξ(x,y) +iη(x,y), which is not analytic. For the transformation to exist, the real transformation functions ξ=ξ(x,y) and η=η(x,y) have to satisfy wave equations in the domain R(xy) and the first-order partial equations ξx=±ηy and ξy=±ηx ["±'' distinguishes transformations of the first (+) and second (−) kinds]. Thus, the hyperbolic transformation theory is different from the conformal mapping theory, where the real transformation functions satisfy the Laplace equation and the Cauchy–Riemann conditions. As applications, the linear Lorentz transformation and nonlinear mappings of time-varying regions into fixed domains are discussed as solutions of the indicated partial differential equations. Furthermore, an initial-boundary-value problem for the electromagnetic wave equation with moving boundary condition is solved analytically (compression of microwaves in an imploding resonator cavity).
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 72 (1992), S. 2472-2477 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: High-fluence KrF-laser-irradiated silicon wafers exhibit a wealth of surface structures, which are different depending on the medium present above the surface during treatment with ultraviolet light. A special surface feature, appearing after treatment under water and in air, is analyzed with a Raman microprobe spectrometer. It is found to consist of leaflike formed silicon structures located above but still attached to the treated surface. During Raman scattering measurements the temperature of these morphological peculiarity rises considerably even at low cw probe laser powers because of geometrically limited thermal conductivity. It is shown that the temperatures, which were derived from the Stokes–to–anti-Stokes scattering intensity ratio are more reliable than those extracted from line shifts since the stress developing inside the Raman laser-heated leaflike microstructures is not known. A Raman microprobe scan of a damage spot, generated by UV treatment under water, reveals in the most cases an enhanced Raman intensity (factor of 10) in comparison with untreated areas. This enhancement is even larger at surface spots of smaller (≤1 μm) sizes and is attributed to the field enhancement of the incident and scattered radiation field caused by geometrical resonances.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 84 (1998), S. 6552-6558 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Using 514 nm radiation and a careful experimental protocol allowing us to make quantitative intensity analyses, we have examined the first- and second-order Raman spectra of five varieties of graphite. These include single-crystal graphite and highly oriented pyrolytic graphite as references, then two with a significant content of c-axis translation faults introduced through grinding and exfoliation, and a last sample which is purely turbostratic. We show that full c-axis stacking disorder results in a strong increase of the scattered E2g-mode intensity. We have further shown that even in those strongly disordered stacking sequences, but in which the AB sequence persists over only a few layers, the doublet around 2700 cm−1 is resolved. We argue against assigning the peak around 1355 cm−1 to "disorder," as is so often done, but to the finite in-plane domain size as proposed a number of years ago; moreover, we suggest that this peak is a more sensitive probe of such small domains than is x-ray diffraction. © 1998 American Institute of Physics.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Physics of Fluids 29 (1986), S. 3626-3630 
    ISSN: 1089-7666
    Source: AIP Digital Archive
    Topics: Physics
    Notes: An idealized statistical theory of chaining in a dilute suspension of macroscopic magnetic particles in a rarefied gas is presented when an external homogeneous magnetic field is present. The primary colloidal particles are assumed to be spherical, of the same size, and to have saturated magnetic moments. The magnetochemical potentials and the association–dissociation equations are derived for chains consisting of v≥1 magnetic grains, in dependence of the temperature T, the density Nv of chains, and the homogeneous magnetic field B0. High field intensities B0 are shown to shift the chain length distribution F=F(v) in favor of long chains, v(very-much-greater-than)1, whereas increasing temperatures T move the maximum of this statistical distribution to smaller chain lengths, v→1. The theory appears to be in qualitative agreement with oven experiments using an external magnetic field for the alignment and stabilization of the chains.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Physics of Fluids 29 (1986), S. 1441-1448 
    ISSN: 1089-7666
    Source: AIP Digital Archive
    Topics: Physics
    Notes: A theory of the diffusion of macroscopic, magnetic particles (suspended in gaseous or liquid media) in density and magnetic field gradients is developed from first principles (Fokker–Planck equation). The influence of the random, fluctuating magnetic fields, produced collectively by the magnetic dipole particles in their thermal motions on the diffusing particle, is taken into account in a self-consistent way. It is shown that the anisotropy in the particle diffusion, caused by the coupling of translational and rotational degrees of freedom (Magnus effect), is small in most physical situations. As an application, the steady-state boundary-value problem for the diffusion of magnetic grains in the inhomogeneous magnetic field of an adsorbing sink dipole and an external, homogeneous magnetic field is solved by means of a stream and Green's functions approach. The coagulation coefficient for magnetic dipole particles in the presence of an external magnetic field is derived. The results are discussed with regard to the coagulation of magnetic grains and the formation of magnetic chains.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 60 (1986), S. 2583-2588 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Theoretical analyses of the compression of axial (i) magnetic and (ii) electric fluxes by means of cylindrical liners are presented for arbitrary large implosion velocities v〈c0. For comparison, quasistatic theories of (i) magnetic and (ii) electric flux compression are given, which are good approximations for nonrelativistic liner speeds v(very-much-less-than)c0. For relativistic liner velocities, significant amounts of electromagnetic radiation would be generated in magnetic or electric flux compression. Relativistic liners can eventually be realized by means of relativistic pulses of electrons of high density. During magnetic flux compression, electrical breakdown is prevented through magnetic self-insulation. The experimental field strengths achievable through electric flux compression are limited by electrical breakdown, since the condition for magnetic self-insulation is not satisfied.
    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...