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
    facet.materialart.
    Unknown
    Chinese Journal of Plant Ecology
    In:  EPIC3Chinese Journal of Plant Ecology, Chinese Journal of Plant Ecology, 47(10), pp. 1453-1463, ISSN: 1005-264X
    Publication Date: 2024-06-21
    Description: Fossil pollen and spore records provide highly creditable proxy data to investigate the past environmental changes such as palaeovegetation and palaeoclimate. Pollen database promotes past environmental studies from local to regional and global scales and from qualitative to quantitative reconstructions. This is of great significance on exploring the interactions among past vegetation, climates and anthropogenic disturbances at large spatial scale and long temporal scale, to better understand the evolution of the earth system. In this paper, a fossil pollen dataset of China is compiled, by synthesizing 372 original or digitized fossil pollen records including 790 pollen taxa in China’s land and ocean during the late-Quaternary (since 50 ka BP). The dataset includes site names, latitude, longitude and altitude, pollen data source, sample type, sediment length or span, sample number of each site, dating method and dating number, age span and reference, as well as the fossil pollen percentage of each sampling site. The pollen data, mostly published from late 1980s to present, are concentrated in vegetation regions of temperate and subtropical forests, temperate grasslands, temperate deserts and alpine vegetation on the Qingzang Plateau. Sample sites are distributed at different altitudes from deep sea to high Qingzang Plateau, but the majority of the sites are located between 0–2 000 m. The dataset comprises of 178 raw pollen records (47.8%) and 194 digitized pollen records (52.2%). Pollen samples are mainly from lake sediment (151 sites), alluvial/fluvial sediment (99 sites), and peat (67 sites), accounting for 85.2% of the total sampling sites. Radiocarbon is the main dating method that accounts for 93.8% of total samples, and most of the sites have 2–10 radiocarbon dating data. Each site has an average number of pollen taxa of 19, with the most sites having 4–30 pollen taxa. The temporal and spatial distribution of representative pollen taxa (Pinus, Quercus, Artemisia and Poaceae) reveals increasing trends both in their distributional range and pollen concentration from the last glacial maximum to Holocene, but such trends have various regional patterns in different parts of China. This fossil pollen dataset is a fruitful work of collection of pollen records in most territory of China that conducted by palynologists from China and overseas during the last half century. It consolidates the valuable and fundamental data that can be potentially utilized to explore the evolution of past environments and their driving mechanism of climate change and human disturbance.
    Repository Name: EPIC Alfred Wegener Institut
    Type: Article , isiRev
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1365-2958
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology , Medicine
    Notes: Helicobacter pylori cells are naturally competent for the uptake of both plasmid and chromosomal DNA. However, we demonstrate that there are strong barriers to transformation of H. pylori strains by plasmids derived from unrelated strains. We sought to determine the molecular mechanisms underlying these barriers. Transformation efficiency was assessed using pHP1, an Escherichia coli–H. pylori shuttle vector conferring kanamycin resistance. Transformation of 33 H. pylori strains was attempted with pHP1 purified from either E. coli or H. pylori, and was successfully introduced into only 11 strains. Digestion of H. pylori chromosomes with different restriction endonucleases (REs) showed that DNA methylation patterns vary substantially among strains. The strain most easily transformed, JP26, was found to have extremely low endogenous RE activity and to lack a restriction–modification (R–M) system, homologous to MboI, which is highly conserved among H. pylori strains. When we introduced this system to JP26, pHP1 from MboI.M+ JP26, but not from wild-type JP26, transformed MboI R−M+ JP26 and heterologous MboI R−M+ wild-type H. pylori strains. Parallel studies with pHP1 from dam+ and dam−E. coli strains confirmed these findings. These data indicate that the endogenous REs of H. pylori strains represent a critical barrier to interstrain plasmid transfer among H. pylori.
    Type of Medium: Electronic Resource
    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 114 (2001), S. 8008-8019 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: This is the first in a two-paper series that investigates the influence of intramolecular vibrational modes on nonlinear, time-domain, electronically resonant signals. Both Transient Grating (TG) and Three Pulse Photon Echo Peak Shift (3PEPS) signals were collected from several probe molecules: Nile Blue, N,N-bis-dimethylphenyl-2,4,6,8-perylenetetracarbonyl diamide, and Rhodamine 6G dissolved in different solvents: benzene, dimethylsulfoxide, and acetonitrile. The effects of excitation of different vibronic transitions on the electronically resonant signals were identified by comparing signals collected with laser pulses at different excitation wavelengths. In the 3PEPS profiles, we find that excitation on the blue edge of the absorption spectrum causes a decreased initial peak shift values and more rapid initial decays, whilst in the TG signals, the magnitude of the "coherent spike" is strongly wavelength dependent. Additional thermally activated vibronic effects were studied via temperature dependent 3PEPS profiles. Our results reveal the sensitivity of the nonlinear signals to the excitation wavelengths and to the distinct vibronic structure of the different chromophores studied. Pronounced modulations in both the 3PEPS and TG signals originating from coherently excited vibrational modes were directly observed. Additional oscillations were observed that are attributed to difference frequencies and higher harmonics of the fundamental modes. In paper II we demonstrate that detailed account of the vibronic nature of the chromophore is required to describe the wavelength dependent signals. © 2001 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 117 (2002), S. 2732-2740 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Frequency-selected vibrational echo experiments were used to investigate the temperature dependences of vibrational dephasing associated with the 0-1 transition of the CO stretching mode of RuTPPCOPy (TPP=5,10,15,20-tetraphenylporphyrin, Py=pyridine) in two solvents: polymethylmethacrylate (PMMA) and 2-methyltetrahydrofuran (2-MTHF). In PMMA, a glass, the echo decay is exponential at all the temperatures studied, and the dephasing rate increases linearly with increasing temperature. In 2-MTHF, there is a change in the functional form of the temperature dependence when the solvent goes through the glass transition temperature (Tg). Below Tg, the dephasing rate increases linearly with temperature, while above Tg, it rises very steeply in a nonlinear manner. In the liquid at higher temperatures, the vibrational echo decays are nonexponential. A model frequency-frequency correlation function (FFCF) is proposed in which the FFCF differs for a glass and a liquid because of the intrinsic differences in the nature of the dynamics. At least two motions, inertial and diffusive, contribute to the vibrational dephasing in the liquids. The different temperature dependences of inertial and diffusive motions are discussed. Comparison of the model calculations of the vibrational echo temperature dependence and the data show reasonable, but not quantitative agreement. © 2002 American Institute of Physics.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    ISSN: 1399-0047
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Chemistry and Pharmacology , Geosciences , Physics
    Notes: LCI is a type of novel antibacterial polypeptide secreted by a Bacillus subtilis strain. It consists of 47 residues with a molecular weight of 5468 Da. Using bioengineering, LCI was expressed in Escherichia coli DH5α with recombinant plasmid pBVAB16. It was crystallized using PEG 4000 as a precipitant. The crystal belongs to space group P6222 or P6422, with unit-cell parameters a = b = 29.30, c = 187.09 Å, and diffracts to 2.44 Å. A set of diffraction data to 2.8 Å was collected.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    s.l. ; Stafa-Zurich, Switzerland
    Materials science forum Vol. 475-479 (Jan. 2005), p. 3137-3140 
    ISSN: 1662-9752
    Source: Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Dendritic is the most observed microstructure in metallic materials. Traditional Cellular Automaton model can only predict the grain structure and grain size. It is necessary for us to modify the original model to reflect the real shape of dendrite. In the paper, a mathematical model was established to describe the evolution of the dendritic shape, in which the influence of microsegregation and curvature on undercooling was taking into account. In addition, the growth model was proposed based on the minimum free energy principle. Modeling results indicated theproposed models can predict not only grain structure, but also dendritic morphology. Free growth of equiaxed grains and the competitive growth of columnar grains were simulated. The modeling results were also validated with experiments
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    ISSN: 1662-9779
    Source: Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
    Topics: Physics
    Notes: Vanadium pentoxide xerogel films intercalated by poly (ethylene oxide), PEO, wereprepared using direct intercalation method via a sol-gel route. The electrical and electrochromiccharacterization of the films were conducted. The electrical properties along and across V-O layershave been evaluated. The results indicate that the proper amount of PEO can increase the electricalconductivity and charge density of the films. The electrochromism of the films upon lithiumintercalation was investigated by ex-situ transmittance measurement. The films display a reversiblemultichromism (orange[removed info] green[removed info] blue) upon Li+ ion insertion/extraction
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    s.l. ; Stafa-Zurich, Switzerland
    Solid state phenomena Vol. 90-91 (Apr. 2003), p. 13-18 
    ISSN: 1662-9779
    Source: Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
    Topics: Physics
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    ISSN: 1662-9779
    Source: Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
    Topics: Physics
    Notes: Bi2V0.9Co0.1O5.5-δ with a pure Aurivillius phase was synthesized by a sol-gel method usingEDTA and citric as mixed complexing agents. It was found that homogeneous and fine powder(100-200 nm) with a pure Aurivillius phase can be produced by calcining the complex precursor at450 ℃ for 1h in air. The sintering properties of Bi2V0.9Co0.1O5.5-δ were investigated in the range of560-680 °C with respect to relativity density. Sintering at 640 °C was ascertained to be preferred forBi2V0.9Co0.1O5.5-δ, producing a dense microstructure with uniform grains around 3-5 μm. TheBi2V0.9Co0.1O5.5-δ ceramic exhibits an oxygen ionic conductivity of 1.0×10-1 S·cm-1 at 600 °C. Thedifference between the activation energies for the ionic conducting in low and high temperatureregions is qualitatively interpreted in terms of an order-disorder phase transition. This researchdemonstrates the advantage of the EDTA-citrate method in preparing Bi2V0.9Co0.1O5.5-δ with respectto the simplicity of synthesis process, desired morphology of synthesized powder, low sinteringtemperature and superior ionic conducting properties of ceramic specimen
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    s.l. ; Stafa-Zurich, Switzerland
    Solid state phenomena Vol. 90-91 (Apr. 2003), p. 19-24 
    ISSN: 1662-9779
    Source: Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
    Topics: 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...