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
Filter
Collection
Language
  • 1
    Publication Date: 2021-09-27
    Description: The Global Carbon Budget 2018 (GCB2018) estimated by the atmospheric CO 2 growth rate, fossil fuel emissions, and modeled (bottom-up) land and ocean fluxes cannot be fully closed, leading to a “budget imbalance,” highlighting uncertainties in GCB components. However, no systematic analysis has been performed on which regions or processes contribute to this term. To obtain deeper insight on the sources of uncertainty in global and regional carbon budgets, we analyzed differences in Net Biome Productivity (NBP) for all possible combinations of bottom-up and top-down data sets in GCB2018: (i) 16 dynamic global vegetation models (DGVMs), and (ii) 5 atmospheric inversions that match the atmospheric CO 2 growth rate. We find that the global mismatch between the two ensembles matches well the GCB2018 budget imbalance, with Brazil, Southeast Asia, and Oceania as the largest contributors. Differences between DGVMs dominate global mismatches, while at regional scale differences between inversions contribute the most to uncertainty. At both global and regional scales, disagreement on NBP interannual variability between the two approaches explains a large fraction of differences. We attribute this mismatch to distinct responses to El Niño–Southern Oscillation variability between DGVMs and inversions and to uncertainties in land use change emissions, especially in South America and Southeast Asia. We identify key needs to reduce uncertainty in carbon budgets: reducing uncertainty in atmospheric inversions (e.g., through more observations in the tropics) and in land use change fluxes, including more land use processes and evaluating land use transitions (e.g., using high-resolution remote-sensing), and, finally, improving tropical hydroecological processes and fire representation within DGVMs.
    Keywords: 551.9 ; atmospheric inversions ; global carbon budget ; dynamic global vegetation models ; carbon cycle
    Language: English
    Type: map
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Publication Date: 2024-04-22
    Description: The Global Consortium for the Classification of Fungi and fungus-like taxa is an international initiative of more than 550 mycologists to develop an electronic structure for the classification of these organisms. The members of the Consortium originate from 55 countries/regions worldwide, from a wide range of disciplines, and include senior, mid-career and early-career mycologists and plant pathologists. The Consortium will publish a biannual update of the Outline of Fungi and funguslike taxa, to act as an international scheme for other scientists. Notes on all newly published taxa at or above the level of species will be prepared and published online on the Outline of Fungi website (https://www.outlineoffungi.org/), and these will be finally published in the biannual edition of the Outline of Fungi and fungus-like taxa. Comments on recent important taxonomic opinions on controversial topics will be included in the biannual outline. For example, ‘to promote a more stable taxonomy in Fusarium given the divergences over its generic delimitation’, or ‘are there too many genera in the Boletales?’ and even more importantly, ‘what should be done with the tremendously diverse ‘dark fungal taxa?’ There are undeniable differences in mycologists’ perceptions and opinions regarding species classification as well as the establishment of new species. Given the pluralistic nature of fungal taxonomy and its implications for species concepts and the nature of species, this consortium aims to provide a platform to better refine and stabilise fungal classification, taking into consideration views from different parties. In the future, a confidential voting system will be set up to gauge the opinions of all mycologists in the Consortium on important topics. The results of such surveys will be presented to the International Commission on the Taxonomy of Fungi (ICTF) and the Nomenclature Committee for Fungi (NCF) with opinions and percentages of votes for and against. Criticisms based on scientific evidence with regards to nomenclature, classifications, and taxonomic concepts will be welcomed, and any recommendations on specific taxonomic issues will also be encouraged; however, we will encourage professionally and ethically responsible criticisms of others’ work. This biannual ongoing project will provide an outlet for advances in various topics of fungal classification, nomenclature, and taxonomic concepts and lead to a community-agreed classification scheme for the fungi and fungus-like taxa. Interested parties should contact the lead author if they would like to be involved in future outlines.
    Keywords: Plant Science ; Ecology ; Evolution ; Behavior and Systematics
    Repository Name: National Museum of Natural History, Netherlands
    Type: info:eu-repo/semantics/article
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 112 (2000), S. 8631-8636 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: An unusually high-peak-temperature desorption state of O2 from Pt{110} (1×2) has been characterized in temperature programmed desorption spectra after O2 adsorption from a supersonic beam at a translational energy of 190 meV and at nozzle temperatures, Tn, greater than 870 K. It shows the characteristics of a subsurface atomic state of oxygen. From the nozzle temperature dependence of the rate of population of this state we conclude that it is formed exclusively from electronically excited O2 1Δg generated in the molecular beam source. © 2000 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
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 109 (1998), S. 10996-11009 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The kinetics of CO chemisorption on both the (1×5) and (1×1) surfaces of Ir{100}, including the CO-induced surface restructuring process, have been studied by measuring the sticking probability as a function of the surface temperature and beam flux. Due to competition between desorption from the (1×5) phase and growth of (1×1) islands, the sticking probability on the initial (1×5) surface is strongly flux-dependent at surface temperatures Ts in the range 480≤Ts≤510 K. It is shown that this is due to a strongly nonlinear dependence of the (1×1) growth rate on the local CO coverage on the (1×5) substrate, with an apparent reaction order of around 5. Desorption energies and pre-exponentials of desorption for CO from both the (1×1) and (1×5) surfaces have been determined by means of a modified lifetime measurement technique. Equilibrium coverages as well as isothermal desorption rates of CO were determined for both surface phases. The zero coverage desorption energy of CO from the (1×1) substrate is 196±5 kJ/mol and from the (1×5) surface it is around 150 kJ/mol. This difference in adsorption energies is the driving force for the CO-induced (1×5) to (1×1) phase transition. TEAS data show that the local CO coverage on the growing (1×1) islands during the phase transformation is 0.5 ML. © 1998 American Institute of Physics.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 106 (1997), S. 10386-10386 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    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 80 (1996), S. 4027-4032 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: A simple technique has been used to measure the two polarization-dependent absorption edges in a single quantum well around 1.5 μm. The broadband spontaneous emission of an AR-coated semiconductor laser chip was used as the spatially coherent light source in conjunction with a grating spectrometer. Absorption edges for both TE and TM polarized light have been measured in single quantum well InGaAs/InGaAsP waveguides and modeled by the k⋅p method. By pumping the devices with a 1.3 μm semiconductor laser, absorption saturation was also studied. The resulting changes in the refractive index were calculated from a Kramers–Kronig transformation of the absorption changes. © 1996 American Institute of Physics.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: High spatial resolution time-resolved photoluminescence has been used to study GaInAs/GaInAsP quantum-well structures selectively intermixed using the pulsed photoabsorption-induced disordering technique. Photoluminescence decay measurements at wavelengths (approximately-greater-than)1.3 μm were obtained using novel high-efficiency photon-counting detectors and were found to correlate spatially with the observed luminescence blue shift in these structures. Results indicate a reduction in the nonradiative recombination time of nearly two orders of magnitude as a result of this intermixing technique. © 1996 American Institute of Physics.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 112 (2000), S. 1937-1945 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The C oxidation reaction on Pt{110}(1×2) has been investigated using molecular beam techniques. The reaction products are CO and CO2. As the surface temperature is increased from 550 to 750 K, the proportion of CO2 produced decreases from ∼50% to 〈1%. When oxygen first impinges on the surface, the formation rate of CO is observed to rise immediately (≤0.1 s), and then rise more slowly to a maximum before decreasing sharply as the C adlayer is depleted. The production of CO2 is initiated after a measurable delay. Angle-resolved product distribution measurements demonstrate that CO desorbs in a sharp lobe centered at an angle of 32° to the surface normal, fitted to cosn(θ−32), where n=50±5. The C oxidation reaction site is identified with the (111) microfacets. It is concluded that two processes are operative, a Langmuir–Hinshelwood mechanism and a reaction in which CO is impulsively desorbed. © 2000 American Institute of Physics.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 112 (2000), S. 4739-4748 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Supersonic molecular beams have been used to study methane dissociative adsorption on Pt{110}(1×2) at incident translational energies of 20 to 700 meV, incident vibrational temperatures of 300 to 800 K and surface temperatures from 400 to 1000 K. At Et≤100 meV, the initial dissociative sticking probability, s0, rises sharply. The process is facilitated by vibrational excitation of the deformation modes and surface temperature. At Et〉100 meV, an activated adsorption process becomes dominant, with an activation barrier of ∼146 meV. At Et≥230 meV, s0 attains a limiting value which is strongly enhanced by excitation of the C–H stretch modes in the incident molecule. An increase in the surface temperature also enhances s0, at all incident translational energies. The mechanistic implications are discussed and it is concluded that the low translational energy process is a distinctive steering-assisted direct adsorption pathway. © 2000 American Institute of Physics.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 109 (1998), S. 6879-6888 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The interaction of oxygen with Pt{110}(1×2) has been investigated using supersonic molecular beams and low-energy electron diffraction (LEED) at incident kinetic energies of 60–900 meV and surface temperatures from 170 to 1100 K. LEED studies indicate that at low exposures and low beam energies (〈190 meV) oxygen does not induce a reconstruction to (1×1). However at high exposures and low beam energies, a variable unit mesh dimension Frenkel–Kontorova domain structure is observed. Sticking probability measurements on the clean surface indicate that oxygen dissociative adsorption on Pt{110}(1×2) is a predominantly precursor mediated process. At low surface temperatures (〈200 K) and low beam energies, the precursor has a strong influence on the adsorption kinetics, and mixed islands of dioxygen and adatoms are formed. Adsorption at beam temperatures below 880 K produces two states in the the thermal desorption spectroscopy spectra, but at higher incident gas temperatures a new high temperature desorption state (Tp=1020 K) can be populated, which inhibits the formation of the usual dissociatively chemisorbed states at Tp=720 and 820 K. © 1998 American Institute of Physics.
    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...