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  (36)
  • Springer Nature  (7)
  • American Institute of Physics (AIP)  (2)
  • 1995-1999  (38)
  • 1980-1984  (7)
  • 1
    Electronic Resource
    Electronic Resource
    Measurement of high-frequency rotational transitions of H2O+ in its ground state by far-infrared laser magnetic resonance (LMR) spectroscopy (1998)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 109 (1998), S. 9744-9752 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Thirteen new rotational transitions of H2O+ in the (0,0,0) level of the X˜ 2B1 state have been measured in the wavenumber region between 80 and 200 cm−1 (50 and 120 μm) by far-infrared laser magnetic resonance (LMR) spectroscopy. LMR data measured previously between 25 and 90 cm−1 (110 and 400 μm), as well as optical and infrared combination differences, have been combined with the new LMR data in a weighted least-squares analysis using an A-reduced expression of the rotational-fine structure Hamiltonian. Thirty-two molecular constants were simultaneously determined, some sextic centrifugal distortion parameters and some quartic and sextic spin-rotation parameters for the first time. From this improved set of molecular parameters, very accurate calculations of rotational term values and zero-field predictions of the 111–000 transition, including hyperfine structure, have been performed. Moreover, the electronic g-tensors and the hyperfine coupling constants are consistent with ab initio calculations which had been carried out for these constants. © 1998 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.477644
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Aggregate model of liquids (1997)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 107 (1997), S. 8697-8705 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Atomic-force pictures reveal a heterogeneous microstructure at the surface of glassy layers which should be similar to one of the many equivalent microstructures a liquid is running through. These microstructures are described with the aid of a kinetic model of reversible aggregation which goes back to formulations as used in the description of living polymerization or aggregation of polymers in solution. Aggregates are considered as dynamic subsystems wherein collective modes of motions are excited. Fluctuations of the aggregates, densely packed in a disordered pattern, leads to a broad size distribution which happens to be controlled by Boltzmann's factor. The disordered structure within the aggregates themselves is optimized, reduced aggregate energy and entropy should be equal. Symmetries are deduced which elucidate many universal properties of the dynamic microstructure of liquids. Thermodynamic properties like the specific heats of aggregation in liquids or the dependence of the glass transition of homologues of linear atactic polystyrene are consistently described. © 1997 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.475022
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    3D-QSAR Analysis and Molecular Modeling Investigations of Piritrexim and Analogous (1997)
    Springer
    Journal of molecular modeling 3 (1997), S. 338-346 
    Details
    ISSN: 0948-5023
    Keywords: Keywords: Free-Wilson-analysis ; PLS ; genetic algorithm ; CoMFA ; piritrexim analogous
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Quantitative structure-activity relationships for piritrexim and analogues acting as inhibitors of tumour cell growth have been derived. First the Free-Wilson-method was used on a homologous training set of eight derivatives. The selection of variables important for the biological activity of the compounds was carried out with different multivariate methods as multiple linear regression, the partial least squares method und a genetic algorithm. The derivation of three-dimensional structure activity relationships started with a systematic conformational analysis of all compounds. For the conformations having minimal energy and being in agreement with the crystal structure of piritrexim charges were calculated with the AM1 hamiltonian. For the superimposition of the derivatives two methods were used: maximal similarity of the common substructure or of the molecular fields. A Comparative Molecular Field Analysis with steric and electrostastic fields identified regions important for the activity of the studied compounds independent of the chosen alignment and also correctly predicted the activity of two nonhomologous compounds.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s008940050048
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Temperature variations in the director orientation and anchoring energy at the surface of cholesteric layers (1996)
    Springer
    JETP letters 63 (1996), S. 43-49 
    Details
    ISSN: 1090-6487
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Slight changes with temperature in the director orientation at the surface of a perfect planar cholesteric liquid crystal (CLC) layer, which are precursors of a jump in the pitch of the cholesteric helix, are observed by measuring the temperature dependence of the optical transmission spectra of the layer. The observed changes in the director orientation are described in the framework of the continuum theory of CLCs, supplemented with allowance for the surface anchoring forces. In particular, the angle of deviation of the director at the surface from the alignment direction at the exact temperature of the jump in pitch is expressed in terms of the anchoring potential. The relation obtained is use to find the anchoring potential in the samples.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1134/1.566961
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Temperature hysteresis of the change in the cholesteric pitch and surface anchoring in thin planar layers (1997)
    Springer
    Journal of experimental and theoretical physics 85 (1997), S. 285-291 
    Details
    ISSN: 1090-6509
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Hysteresis of the temperature of jumps in the cholesteric pitch in planar layers of cholesteric liquid crystals (CLCs) has been observed in the temperature dependence of the optical transmission spectra measured in a 4.8 ¼m thick specimen of a 60% chiral racemic mixture of CE6. The temperature difference for the pitch jumps during heating and cooling was equal to about 0.1°C near 40.3°C. No difference in the temperature of the pitch jumps during heating and cooling was observed for an 18 µm thick specimen. A theoretical description of this hysteresis is presented on the basis of a continuum theory of elasticity of CLCs that also takes account of the surface anchoring of the CLC. Different possible mechanisms leading to a change in the director configuration in the layer during a pitch jump and their correspondence to the jump mechanism and hysteresis which occur in the experimental specimens are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1134/1.558276
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Structure and dynamics of human interphase chromosome territories in vivo (1998)
    Springer
    Human genetics 〈Berlin〉 102 (1998), S. 241-251 
    Details
    ISSN: 1432-1203
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract A new approach is presented which allows the in vivo visualization of individual chromosome territories in the nuclei of living human cells. The fluorescent thymidine analog Cy3-AP3-dUTP was microinjected into the nuclei of cultured human cells, such as human diploid fibroblasts, HeLa cells and neuroblastoma cells. The fluorescent analog was incorporated during S-phase into the replicating genomic DNA. Labelled cells were further cultivated for several cell cycles in normal medium. This well-known scheme yielded sister chromatid labelling. Random segregation of labelled and unlabelled chromatids into daughter nuclei resulted in nuclei exhibiting individual in vivo detectable chromatid territories. The territories were composed of subcompartments with diameters ranging between approximately 400 and 800 nm which we refer to as subchromosomal foci. Time-resolved in vivo studies demonstrated changes of positioning and shape of territories and subchromosomal foci. The hypothesis that subchromosomal foci persist as functionally distinct entities was supported by double labelling of chromatin with CldU and IdU, respectively, at early and late S-phase and subsequent cultivation of corresponding cells for 5–10 cell cycles before fixation and immunocytochemical detection. This scheme yielded segregated chromatid territories with distinctly separated subchromosomal foci composed of either early- or late-replicating chromatin. The size range of subchromosomal foci was similar after shorter (2 h) and longer (16 h) labelling periods and was observed in nuclei of both living and fixed cells, suggesting their structural identity. A possible functional relevance of chromosome territory compartmentalization into subchromosomal foci is discussed in the context of present models of interphase chromosome and nuclear architecture.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004390050686
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Über die lokale Zetafunktion von Shimuravarietäten. Monodromiefiltration und verschwindende Zyklen in ungleicher Charakteristik (1982)
    Springer
    Inventiones mathematicae 68 (1982), S. 21-101 
    Details
    ISSN: 1432-1297
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01394268
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Optical Properties and Dimer Formation in Copper Phthalocyanine-Doped Sol-Gel Matrices (1998)
    Springer
    Journal of sol gel science and technology 11 (1998), S. 241-250 
    Details
    ISSN: 1573-4846
    Keywords: copper phthalocyanine ; dimer ; monomer ; optical absorption
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Dimer formation in sol-gel matrices was studied using optical absorption spectroscopy of copper phthalocyanine tetrasulfonate dopants in silicate and aluminosilicate sol-gel matrices. Changes in the optical absorption spectra of dimers and monomers were correlated with various stages of the sol-gel process. Dimerization is strongly influenced by the chemistry of the pore liquid. The primary factors that control dimerization are the quantity of solvent remaining in the pores, pore solvent alcohol/water ratio, and presence of protons which can be either from the catalyst or from silanol groups on the silicate pore surfaces. Synthesis conditions which cause dye protonation invariably lead to dimerization during the latter stages of drying when the pore liquid becomes water-rich and there is a high dye concentration. These studies also identify chemical conditions which are able to avoid dye protonation and subsequently reduce dimer formation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1008602111839
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Encapsulation of the ferritin protein in sol-gel derived silica glasses (1996)
    Springer
    Journal of sol gel science and technology 7 (1996), S. 109-116 
    Details
    ISSN: 1573-4846
    Keywords: ferritin ; sol-gel ; magnetism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract A significant recent development in sol-gel science has been the encapsulation of biomolecules such as proteins and enzymes in optically transparent silica glasses. This paper reports on the encapsulation of an iron (Fe) storage protein, ferritin, to develop a magnetic silica glass. Native ferritin, which has a nanometer-sized microcrystalline Fe oxide core, was encapsulated in optically transparent silica glasses using the sol-gel process. Fe could be released from ferritin but could not be reconstituted into apoferritin when the protein was trapped in the pores of the glass. Transmission electron microscopy of ferritin-doped aged silica gels indicated that crystallinity of the Fe oxide core was retained upon sol-gel encapsulation. Magnetic measurements on ferritin-doped silica gels indicated the material to be paramagnetic, but not superparamagnetic.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00401890
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Enzymatic activity of oxalate oxidase and kinetic measurements by optical methods in transparent sol-gel monoliths (1996)
    Springer
    Journal of sol gel science and technology 7 (1996), S. 117-121 
    Details
    ISSN: 1573-4846
    Keywords: sol-gel monoliths ; immobilized enzyme ; oxalate oxidase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Novel synthetic techniques are used for the encapsulation of the enzymes oxalate oxidase and peroxidase in stable, optically transparent porous silica glass matrices. The large enzymes are fully immobilized in the porous glass but small molecules such as oxalate ions pass readily through the pores in the glass. The enzymes catalyze the reactions leading to the formation of a colored dye product. Upon exposure of the doped glass to oxalate solutions, a colored glass is formed. The absorption spectrum of the colored product and the changes of absorbance with time are measured within the glass matrix. The sensitivity and the time-dependence of the response are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00401891
    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...