Library

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
  • 1
    Electronic Resource
    Electronic Resource
    The Role of Panicum virgatum (Switch Grass) in the Revegetation of Iron-Mine Tailings in Northern New York (1995)
    Oxford, UK : Blackwell Publishing Ltd
    Restoration ecology 3 (1995), S. 0 
    Details
    ISSN: 1526-100X
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: We investigated the role of artificially introduced Panicum virgatum (switch grass) on the sequential natural revegetation of 15- and 35-year-old tailings in the Adirondack region of northern New York. Switch grass covered approximately 48% of the 15-year-old Chaumont Tailings. Establishment of switch-grass stands improved the fertility of the site by adding organic matter, raising pH, and elevating cation exchange capacity and concentrations of major nutrients (N, P, and K). Switch-grass stands also aided the initial recruitment of such pioneer species as Populus spp. (aspens), Salix spp. (willows), and Betula spp. (birches). This facilitation of recruitment of woody species is explained as follows: (1) robust switch-grass stands physically captured the wind-disseminated seeds of these species; (2) switch grass acted as a “nurse crop” for these species, thus these species were able to increase their density vigorously through root or stem sprouting; (3) a combination of both. Switch grass decreased its cover (14%), however, as observed in the 35-year-old South Tailings. As switch grass declined, such vigorous “root-suckering” species as aspens increased in dominance, followed by the invasion of Prunus pensylvanica (pin cherry).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1526-100X.1995.tb00085.x
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Experimental Restoration of Native Vegetation in Indiana Dunes National Lakeshore (1998)
    Cambridge, MA, USA : Blackwell Publishing Inc
    Restoration ecology 6 (1998), S. 0 
    Details
    ISSN: 1526-100X
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: We investigated the effects of prescribed fire, herbicide treatment, and sod removal on the eradication of exotic grasses and the establishment of native plant species in 24 experimental restoration plots in three razed residential sites within the boundary of Indiana Dunes National Lakeshore. During 1992–1995, herbicide treatment and sod removal decreased the combined cover of Poa pratensis (Kentucky blue grass) and Agropyron repens (quackgrass) significantly (from 82% to 13%, and 85% to 8%, respectively), whereas fire did not suppress such exotic lawn grasses. In 1993, several opportunistic species, represented by Cyperus spp. (umbrella sedges), Digitaria sanguinalis (crab grass), and Ambrosia artemisiifolia (common ragweed), filled the gaps left by the removal of lawn grasses. For the same period, Detrended Correspondence Analysis revealed a clear vegetation divergence between the control-fire plots and the herbicide-sod removal plots. While Poa pratensis and Agropyron repens continued to dominate the control and fire plots, the planted native species, represented by Schizachyrium scoparium (little blue-stem), Sorghastrum nutans (Indian grass), Rudbeckia hirta (black-eyed Susan), and Monarda punctata (horsemint), began to dominate in the herbicide and sod removal plots from 1994. In both herbicide and sod removal plots, the ground cover of grasses (68%) was much higher than the forbs (10%). The herbicide plots, where exotic species were removed but nitrogen-rich top soils were not removed, showed a higher diversity of planted native species than the sod removal plots (where both exotic species and top soils were removed) and the control-fire plots (where neither was removed). This finding suggests that an optimum but not excessive concentration of soil nitrogen is needed to support a maximum species diversity in such infertile substrate as sandy soil. In addition, the decrease in potassium in all plots, regardless of treatment, suggests that potassium may become a limiting factor for our restored native vegetation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1526-100x.1998.06114.x
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Evaluating the effects of optical and carrier losses in etched-post vertical cavity lasers (1995)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 78 (1995), S. 5871-5875 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We demonstrate the combined effects of optical scattering loss and surface recombination (or carrier diffusion) on the performance and scalability of etched-post vertical cavity lasers (VCLs). The size dependence of optical losses and threshold gain are determined from pulsed measurements of external quantum efficiency. Deeper etch depths result in a stronger radial dependence of the threshold gain, which quickly increases the threshold current density. With optical loss accounted for, pulsed threshold current density measurements give the extra information needed for evaluating carrier loss. Surface recombination or carrier diffusion also results in threshold current density increases, but scalability is ultimately limited by the ability of the active region to provide enough gain for smaller size, higher optical loss devices. Even with these losses, three-quantum-well VCLs with shallow etches have threshold currents as low as 420 μA. © 1995 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.360588
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Antimonides with the half-Heusler structure: New thermoelectric materials (1999)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 74 (1999), S. 1415-1417 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The thermoelectric properties near ambient temperature of half-Heusler alloys based on LnPdSb, where Ln=Ho, Er, and Dy are reported. The Seebeck coefficients are large, between 60 and 250 μV/K, and the materials are p type. The resistivities are between 0.6 and 20 mΩ cm. Thermal conductivities are between approximately 5.0 and 3.5 W/mK at 300 K, and are smallest in intentionally disordered materials. The highest ambient temperature ZT obtained is 0.06. Band-structure calculations are presented for LuPdSb. It is suggested that half-Heusler alloys with 18 electrons per formula unit may represent a large class of thermoelectric materials. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.123596
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Near-field scanning optical spectroscopy of an InGaN quantum well (1998)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 72 (1998), S. 927-929 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Near-field scanning optical microscopy is used to image photoluminescence (PL) in an InGaN/GaN quantum well (QW) with spatial resolution of approximately 100 nm for temperatures between 50 and 295 K. Strong (∼50%) fluctuations in the quantum well photoluminescence as well as a tenfold enhancement of deep level-related emission at lower energies occur at large (∼500 nm diam) pits in the heterostructure. Regions of smaller (∼15%) fluctuations in the QW PL are not correlated with the presence of pits. The spectrum of the QW PL shows no significant variations on the length scales probed in this experiment. We thus find no spectroscopic signature of the recombination of strongly localized carriers at temperatures above 50 K. © 1998 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.120875
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Wideband scanning of a guided-light beam and spectrum analysis using magnetostatic waves in an yttrium iron garnet-gadolinium gallium garnet waveguide (1989)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 54 (1989), S. 196-198 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Wideband scanning of a light beam through the use of magnetostatic waves has been accomplished for the first time. Specifically, a guided-light beam at a wavelength of 1.317 μm in an yttrium iron garnet-gadolinium gallium garnet waveguide was Bragg diffracted by magnetostatic forward volume waves (MSFVWs) operating at a frequency range of 2–7 GHz. Wideband scanning of the light beam was accomplished simply by changing the frequency of the MSFVW continuously from center frequencies of 2.5 and 6.0 GHz while keeping the dc magnetic field fixed or by continuously tuning the dc magnetic field while keeping the frequency of the MSFVW fixed at the center frequencies. A large number of resolvable scan spot positions were obtained in both cases. The resulting wideband magneto-optic Bragg cell or light beam scanner was also used to perform spectral analysis of wideband rf signals at a center frequency of 3.2 GHz. Potential advantages of the magneto-optic Bragg cell and scanner over the existing acousto-optic counterparts also identified.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.101006
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Sound velocity and index of refraction of AlAs measured by picosecond ultrasonics (1988)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 53 (1988), S. 2023-2024 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We use picosecond optics techniques to generate and detect acoustic pulses in an epitaxially grown film of AlAs. From the round trip time of the acoustic pulse we find a sound velocity in the [100] direction of 6.4×105 cm s−1. We also show how measurements of this type can be used to determine the refractive index.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.100309
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    GHz bandwidth magneto-optic interaction in yttrium iron garnet-gadolinium gallium garnet waveguide using magnetostatic forward volume waves (1988)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 53 (1988), S. 1696-1698 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Very large bandwidth noncollinear coplanar magneto-optic interaction with magnetostatic forward volume waves in an yttrium iron garnet-gadolinium gallium garnet (YIG-GGG) waveguide is reported for the first time. Bandwidths of 0.78 and 1.03 GHz centered, respectively, at the carrier frequencies of 2.5 and 6.0 GHz, and TM0 -TE0 mode-conversion efficiencies of 0.54 and 0.50% have been achieved at the optical wavelength of 1.317 μm using a single microstrip transducer and homogeneous dc magnetic fields of 2200 and 3500 Oe. A summary of related coupled-mode analysis is also presented.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.99800
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Ion-milled lenses and lens arrays in yttrium iron garnet-gadolinium gallium garnet waveguides (1989)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 55 (1989), S. 2271-2273 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Waveguide lenses have been formed for the first time in yttrium iron garnet-gadolinium gallium garnet (YIG-GGG) waveguides by using ion milling. Hybrid-type single lenses, lens arrays, and collimation-Fourier-transform lens pairs fabricated have shown good efficiency and near-diffraction-limited focal spot sizes. These waveguide lenses should facilitate realization of magnetostatic wave based integrated magneto-optic device modules for applications in communications and signal processing.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.102035
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    X-band magneto-optic Bragg cells using bismuth-doped yttrium iron garnet waveguides (1989)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 55 (1989), S. 2242-2244 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Guided-wave magneto-optic Bragg cells at X-band microwave frequencies using magnetostatic forward volume waves (MSFVWs) in bismuth-doped yttrium iron garnet-gadolinium gallium garnet (Bi-doped YIG-GGG) waveguides are reported for the first time. Performance figures that have been obtained at an optical wavelength of 1.303 μm include a center frequency tuning range of 3.7–12.0 GHz, a diffraction efficiency of 12% at the magnetostatic wave power of 56 mW, a linear dynamic range 〉40 dB, and a −3 dB magneto-optic bandwidth of 150 MHz. These results represent a significant improvement over those obtained previously with the Bragg cells using pure YIG-GGG waveguides. Maximum scan angle of 6° and 5.3° were also measured, respectively, by tuning the rf frequency ∼10.0 GHz at a fixed dc magnetic field of 3660 Oe and by varying the dc magnetic field ∼3660 Oe at a fixed rf frequency of 10.0 GHz. A frequency resolution of 30 MHz was measured with rf spectral analysis experiments carried out at 12 GHz. Finally, a Faraday rotation coefficient as large as −2313°/cm was measured for the Bi-doped YIG-GGG waveguides.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.102070
    Library Location Call Number Volume/Issue/Year 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...