ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
Filter
  • Springer  (15)
  • 2000-2004  (2)
  • 1995-1999  (11)
  • 1980-1984  (2)
  • 1
    Electronic Resource
    Electronic Resource
    Distribution of calmodulin protein and mRNA in growing pollen tubes (1998)
    Springer
    Sexual plant reproduction 11 (1998), S. 131-139 
    Details
    ISSN: 1432-2145
    Keywords: Key words Calmodulin ; mRNA ; Calcium ; Pollen tube ; Agapanthus umbellatus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  Pollen tube growth is a vital process for angiosperm fertilisation and is dependent on the presence of a tip-focused gradient of cytosolic free calcium ([Ca2+]c). In order to clarify some of the target molecules which convey the Ca2+ signal information, we investigated calmodulin distribution during tube growth. Fluorescently labelled calmodulin was pressure microinjected into pollen tubes and its distribution monitored by confocal microscopy. Calmodulin distributes evenly throughout the cell, but some of its binding sites form a V-shaped collar behind the apical region. This specific association dissipates upon growth arrest, and suggests an interaction of calmodulin with cytoskeletal-bound target proteins. The distribution of calmodulin mRNA was also analysed by microinjection of fluorescently labelled mRNA. No specific pattern was observed, with an even localisation in the body of tube and a lower concentration in the cell apex. Studies with localised application of inhibitors/activators indicate that calmodulin plays a crucial role in tip elongation but does not direct tube orientation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004970050130
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Asymmetric multimode Y-junction splitters (1997)
    Springer
    Optical and quantum electronics 29 (1997), S. 379-392 
    Details
    ISSN: 1572-817X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Notes: Abstract The wavelength-independent, non-reciprocal splitting properties of the asymmetric, multimode Y-junction make it an ideal device for use as a low-loss, low-power tap in a concatenated linear bus. The properties of a two-dimensional slab model of the junction are investigated and the results of ray-tracing, modal and numerical beam propagation method (BPM) techniques are compared. Minimization of splicing loss between the ports of a square-core, three-dimensional buried channel waveguide version of the device and a multimode fibre is also addressed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1018582912154
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Limitations in the perturbation analysis of bent finite-clad fibres and waveguides (1995)
    Springer
    Optical and quantum electronics 27 (1995), S. 15-33 
    Details
    ISSN: 1572-817X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Notes: Abstract The transverse shift in the field distribution and the correction to the propagation constant of the fundamental and symmetric cladding modes on bent finite-clad single-mode fibres and slab waveguides are evaluated from perturbation theory for effective index values extending below the cladding index. Analytical results are derived in both geometries for the step-profile that are valid within the overall limitations of the theory. However, it is found that, for the fibre geometry only, the method breaks down at certain discrete wavelengths because of degeneracies that occur between the HE12 (LP02) and TE01 (LP11) mode propagation constants.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00431030
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Variational approximations for higher-order modes of weakly-guiding fibres (1984)
    Springer
    Optical and quantum electronics 16 (1984), S. 41-48 
    Details
    ISSN: 1572-817X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Notes: Abstract Simple approximations for the fields and propagation constants of low-order modes on circular weakly guiding fibres are derived using variational techniques. The high accuracy of these approximations for quasi-parabolic profiles is demonstrated in the case of the Gaussian profile, for which there are no analytical solutions of the scalar wave equation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00619876
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Generation of spatial solitons using non-linear guided modes (1998)
    Springer
    Optical and quantum electronics 30 (1998), S. 751-770 
    Details
    ISSN: 1572-817X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Notes: Abstract We investigate how two-dimensional spatial optical solitons can be generated in a non-linear Kerr medium using the non-linear guided modes of a weakly-guiding slab waveguide with a linear core and a non-linear cladding as the source of excitation. Symmetric, antisymmetric and asymmetric non-linear modes are considered, from which we determine the parameters of single solitons, oscillating two-soliton bound states, and two repelling solitons, respectively. Both the beam propagation method and inverse scattering transform are used.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1006941515679
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Multimode planar devices (1999)
    Springer
    Optical and quantum electronics 31 (1999), S. 307-326 
    Details
    ISSN: 1572-817X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Notes: Abstract We derive simple analytical expressions, using geometric optics, to describe the power output characteristics of various multimode devices, including acute angle X-junctions, symmetric Y-junctions and multimode interference couplers. The ray-tracing results compare well with results obtained using a finite difference beam propagation method solution of the governing scalar wave equation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1006971108806
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    On the right-angle X-junction diffraction model (1995)
    Springer
    Optical and quantum electronics 27 (1995), S. 261-266 
    Details
    ISSN: 1572-817X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Notes: Abstract We review the important features of the right-angle X-junction diffraction model and discuss both its theoretical framework and its validity range. In addition, we present explicit new results from BPM calculations that show that the analytical model aptly describes the dominant physical processes involved and provides bounds on the numerical results. We also address some misinterpretations of the model that have recently appeared in the literature.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00631752
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Analysis and design of highly broad-band, planar evanescent couplers (1996)
    Springer
    Optical and quantum electronics 28 (1996), S. 71-81 
    Details
    ISSN: 1572-817X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Notes: Abstract It is shown that by taking advantage of the maximum in the spectral dependence of the coupling coefficient, very broad-band symmetric and asymmetric single-mode planar couplers can be designed. The symmetric coupler allows at least 95.6% coupling between the two cores over the wavelength range 1.3–1.58 μm, while the asymmetric coupler can act as a 3 dB splitter with only ±1.6% variation in the splitting ratio over the wavelength range 1.3–1.67 μm. In both cases, the design includes the curved input-output arms, and the estimated bend loss is approximately 0.1 dB.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00578552
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Coupling characteristics of photo-induced Bragg gratings in depressed- and matched-cladding fibre (1996)
    Springer
    Optical and quantum electronics 28 (1996), S. 1641-1654 
    Details
    ISSN: 1572-817X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Notes: Abstract Experimental transmission spectra of ultraviolet (u.v.)-written Bragg gratings in depressed- and matched-cladding fibre are characterized and compared. In particular, we discuss how the location and strength of the spectral features vary with the degree of blazing, or angular tilt of the grating. The fine-structure detail on the short-wavelength side of the fundamental Bragg line is attributed to power coupling between the forwardpropagating fundamental (LP01) mode and discrete, backward-propagating cladding modes. Resonances corresponding to backward-propagating LP0n and LP1n modes are identified, and their relative strengths are compared with theoretical overlap calculations. Physical arguments are presented that explain the pronounced ‘ghost’-grating notch that appears in the transmission spectra of blazed, fibre Bragg gratings in depressed-cladding fibre.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00331054
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Asymmetric, adiabatic multipronged planar splitters (1996)
    Springer
    Optical and quantum electronics 28 (1996), S. 353-369 
    Details
    ISSN: 1572-817X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Notes: Abstract This paper analyses the adiabatic forked splitter, a device for separating the power in different modes of a multimoded waveguide into distinct, single-mode waveguides. The concept of two-mode separation in asymmetric Y-splitters is generalized to several modal channels, and the resulting multipronged devices are studied in detail, thus addressing important issues such as (1) the achievement of optimally-short devices, (2) the minimization of radiation loss, and (3) the splicing of the device to external optical components. An approximate relationship is derived between the number of modal channels and the required device length, thus showing that there is an upper limit of about four modal channels, for practical fabrication in planar geometry.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00287024
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...