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
    A density functional study of carbon monoxide adsorption on small cationic, neutral, and anionic gold clusters (2002)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 117 (2002), S. 4010-4015 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: CO adsorption on small cationic, neutral, and anionic Aun (n=1–6) clusters has been investigated using density functional theory in the generalized gradient approximation. Among various possible CO adsorption sites, the on-top (one-fold coordinated) is found to be the most favorable one, irrespective of the charge state of the cluster. In addition, planar structures are preferred by both the bare and the CO-adsorbed clusters. The adsorption energies of CO on the cationic clusters are generally greater than those on the neutral and anionic complexes, and decrease with size. The adsorption energies on the anions, instead, increase with cluster size and reach a local maximum at Au5CO−, in agreement with recent experiment. The differences in adsorption energies for the different charge states decrease with increasing cluster size. © 2002 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1483067
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Atomic and electronic structure of neutral and charged SinOm clusters (1998)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 109 (1998), S. 1245-1250 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Using molecular orbital approach and the generalized gradient approximation in the density functional theory, we have calculated the equilibrium geometries, binding energies, ionization potentials, and vertical and adiabatic electron affinities of SinOm clusters (n≤6,m≤12). The calculations were carried out using both Gaussian and numerical form for the atomic basis functions. Both procedures yield very similar results. The bonding in SinOm clusters is characterized by a significant charge transfer between the Si and O atoms and is stronger than in conventional semiconductor clusters. The bond distances are much less sensitive to cluster size than seen for metallic clusters. Similarly, calculated energy gaps between the highest occupied and lowest unoccupied molecular orbital (HOMO-LUMO) of (SiO2)n clusters increase with size while the reverse is the norm in most clusters. The HOMO-LUMO gap decreases as the oxygen content of a SinOm cluster is lowered eventually approaching the visible range. The photoluminescence and strong size dependence of optical properties of small silica clusters could thus be attributed to oxygen defects. © 1998 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.476675
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Experimental study of the nature of the glass transition process in monohydroxy alcohols (1993)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 99 (1993), S. 5362-5368 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The nature of the glass transition process in six monohydroxy alcohols, viz., the isomers of butanol, 2-propanol, and 3-methyl–1-butanol had been studied in detail using dielectric spectroscopy (frequency range 10+6–10−3 Hz) and differential scanning calorimetry (DSC). Measurements were made down to a temperature of 77 K in dielectric experiments and a temperature of 95 K in DSC. These results together with the published microwave data on these liquids reveal the existence of two glass transition processes—one due to the hydrogen bonded network which is very dominant and the other one due to the nonhydrogen bonded molecules, which is much weaker. Associated with the latter process, there is a secondary (or β-) relaxation process whose activation energy varies from 4.8 to 6.7 kcal/mol which is dependent on the shape and size of the liquid molecules. In addition to the β process, all the alcohols revealed yet another sub-Tg (γ) process whose activation energy varies from 2.1 to 2.6 kcal/mol and is found to be little dependent on the molecular shape. These results perhaps indicate that the β process is somehow connected to the relaxation of the free monomeric molecule and the γ process to that of hydroxyl group rotation, respectively.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.466187
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Dielectric relaxation studies of glass formation in some esters of phthalic acid (1993)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 99 (1993), S. 1607-1613 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Dielectric relaxation studies have been made on a series of dialkyl esters of phthalic acid over a frequency range of 20 Hz to 1 MHz and over a temperature range of 77 to 573 K. Studies have also been made above room temperature (up to 363 K) at microwave frequencies of 5.3, 10, and 32 GHz. All the samples in their supercooled liquid state reveal yet another process in addition to the primary or α process. Careful measurements have been made to resolve the secondary or β process from the α process at temperatures above Tg. The activation energy of the β process decreases from 39 KJ/mole to 20 KJ/mole with increase in the size of the alkyl group. It is also noted that the bifurcation of liquid relaxation into α and β processes occurs at much higher temperature with increase in the alkyl group. A sharp increase with temperature in the magnitude of the β process in the vicinity of the glass transition Tg temperature, is noted. The relevance of these observations to glass formation in liquids is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.465329
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    POST MENOPAUSAL BLEEDING ASSOCIATED WITH EXTRAMEDULLARY MYELOMATOSIS (1967)
    Oxford, UK : Blackwell Publishing Ltd
    BJOG 74 (1967), S. 0 
    Details
    ISSN: 1471-0528
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1471-0528.1967.tb03797.x
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Detection of antibodies bound to tumor cell surface antigens with radioiodinated Staphylococcus aureus protein A (SPA) (1979)
    Springer
    Cancer immunology immunotherapy 5 (1979), S. 243-252 
    Details
    ISSN: 1432-0851
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Staphylococcal protein A (SPA) is known to bind to the Fc portion of certain subclasses of IgG. On the basis of this property, radioiodinated SPA (125I-SPA) was used to detect antibodies reacting with surface antigens of tumor cells. Target cells derived from an osteosarcoma growing in C3H/fHeJ mice and antiserum to this tumor prepared in female Hartley guineapigs were used to establish optimum conditions for the assay. Similar optimum conditions were also determined for human melanoma target cells. Target cells were plated at a concentration of either 3×105 cells per well or 1×105 cells per well in Microtest II plates, and allowed to form semiconfluent monolayers for 24–48 h respectively. Target cells thus prepared were treated with antiserum and then with 125I-SPA. A minimum of 30 min incubation time was found to be optimal for the antigen-antibody reaction. The quantity of 125I-SPA bound to antisera-treated target cells was found to depend on the time of incubation with 125I-SPA and on the concentration of SPA used. Longer incubation times and increasing concentrations of SPA resulted in greater amounts of 125I-SPA being bound to antiserum treated target cells. This assay was employed for the detection of antibodies in the sera of two melanoma patients and two colon carcinoma patients. The results of absorption analysis suggest that the antibody activity in the sera of the melanoma patients may be of four different specificities: (a) autoantibodies, (b) alloantibodies, (c) antibodies reacting with common, cross-reacting melanoma-associated antigens, and (d) antibodies reacting with unique antigens specific for autologous melanoma cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00200147
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Small-angle X-ray scattering studies of a natural fiber: Agave cantala (1980)
    Springer
    Polymer bulletin 2 (1980), S. 189-194 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary Agave cantala, a natural fiber is considered as a densely packed colloidal system belonging to the general micelle system and the well known theories of KRATKY and POROD have been utilized to evaluate some macromolecular parameters of the scattering inhomogeneities in it. The small-angle KRATKY Camera of the latest design has been used for experimental measurements. The parameters evaluated are the specific inner surface, transversal lengths like the length of inhomogeneity and the length of coherence and the air fraction of the scattering particles in Agave cantala fiber; these were found to be
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00254583
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Correlation between macromolecular parameters and the average breaking strength of agave fibers (1984)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 22 (1984), S. 3407-3415 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The small-angle X-ray scattering method was applied to evaluate macromolecular parameters of Agave fibers (Agave sisalana, A. cantala, A. hybrid, A. elongata, and A. ameniensis). The macromolecular parameters such as specific inner surface, percentage of void, length of coherence, range of inhomogeneity, and transversal lengths were evaluated. The correlation of macromolecular parameters with the average breaking strength of Agave fibers did not lead to a linear relation, however, the specific macromolecular organization in A. sisalana manifested higher breaking strength.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1984.170221156
    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...