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
  • Polymer and Materials Science  (45)
  • Analytical Chemistry and Spectroscopy  (22)
  • Abscisic acid
  • 1990-1994  (58)
  • 1975-1979  (10)
  • 1965-1969
Collection
Publisher
Years
Year
  • 1
    ISSN: 0951-4198
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Physics
    Notes: The main fragmentation pathway of vinyl triflates in mass spectra involves the loss of CF3SO2·, followed by the loss of olefin and/or CO. The loss of TfOH takes place with fragmentation of a vinylic C—H bond. TfOH2+ ions are formed via regiospecific double hydrogen transfer from five- and six-membered cyclic triflates.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 0030-493X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 0049-8246
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Physics
    Notes: This work suggests a theoretical approach for the description of a primary x-ray beam by means of the K fluorescence which it excites on a set of thin targets made of pure elements. Physical quantities, defined as weighted integrals over hv of the photon spectral distribution, are obtained directly as weighted integrals of the Kα yields over the variable Ez (the ionization energy of the K shell of the element with atomic number Z), without needing any explicit reconstruction of the spectral distribution. The set of Kα yields produced by an x-ray beam as a function of Ez is a functional description of the exciting beam. Theoretically, such a description is suited to x-ray fluorescence analysis.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    ISSN: 0749-1581
    Keywords: 1H, 13C, 15N and 113Cd NMR ; Two-dimensional NMR ; CP/MAS NMR ; Hg and Cd complexes 4(1H) -Quinazolinone-2,3-dihydro-2-thioxo ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The Cd(II) and Hg(II) complexes of 4(1H)-quinazolinone-2,3-dihydro-2-thioxo (1) and the free ligand were studied by 1D and 2D multinuclear magnetic resonance in solution and 13C cross polarization magic angle spinning NMR in the solid state. Compound 1 adopts only one of five possible tautomeric structures in solution, namely the thiouracyl-like structure. It was found that the metal atom is linked to two molecules of deprotonated 1 by N-1 and coordinated by the sulphur atom. The compounds retain the same structure in the solid state and in dimethyl sulphoxide solution.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Planta 141 (1978), S. 141-144 
    ISSN: 1432-2048
    Keywords: Abscisic acid ; Dormancy (seeds) ; Germination (seeds) ; Inhibitors (seeds germination) ; Pinus ; Seed coat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Inhibitors from (Pinus pinea L.) seed coats were separated using paper chromatography, thin layer chromatography, and a Sephadex G-10 column. The inhibitory activity was resolved into several fractions. One of these behaved similarly to abscisic acid. It has exhibed the same properties as ABA in thin-layer chromatography, paper chromatography, and Sephadex G-10 chromatography and in UV absorption and fluorescence spectra. These germination inhibitors, present in the seed coats, are involved in the regulation of P. pinea seed germination.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 178 (1990), S. 1-16 
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Die seit langem in der Literatur als “Indophenin-Reaktion” bekannte Umsetzung von Isatin mit Thiophen wurde systematisch untersucht und auf die Umsetzung mit Bithiophen erweitert. Die Reaktionsprodukte wurden isoliert und durch FT-IR, UV, 1H-NMR, 13C-NMR sowie GPC charakterisiert.Im Gegensatz zu den Literaturdaten wurden Reaktionsprodukte mit höheren Molgewichten und anderer Molmassenverteilung gefunden. Die Reaktionsbedingungen - Lösungsmittel, Temperatur und Konzentration - sind für den Reaktionsablauf und die entstehenden Produkte von entscheidender Bedeutung.Füur die oligomeren Reaktionsprodukte werden neue Strukturen vorgeschlagen, die in Übereinstimmung mit allen analytischen Daten sind. Anhand eines Formelschemas werden die Reaktionen des Isatins mit Thiophen (Bithiophen) erläutert.
    Notes: A systematic study of the well-known indophenin reaction between isatin and thiophene was extended to embrace bithiophene. The products of the reactions were isolated and characterized by FT-IR, UV, 1H-NMR, 13C-NMR, and GPC. The values of the thus determined molar masses and molar mass distributions differed from the data given in the literature. The reaction conditions - solvent, temperature, and concentration - are of crucial importance for the course of the reaction and the products obtained.New structures suggested for the oligomeric reaction products agree with all the analytical data. The reactions between isatin and thiophene (bithiophene) are explained schematically.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The translational and rotational diffusion coefficients and the intrinsic viscosity of semiflexible, randomly broken, and wormilike chains have been obtained by Monte Carlo simulation in the context of the rigid-body treatment. Both approximate and rigorous rigid-body hydrodynamics are used, so that the error introduced by the approximate methods can be evaluated. A randomly broken chain and a wormilike chain having the same contour length and persistence length have the same radius of gyration but different values for any of the hydrodynamic properties. The two types of chains are compared in this regard. Considering that the cross section of the chain is represented by a cylinder better than by a string of spheres, we devise a cylindrical correction to be applied to the results simulated for chains of beads. Application is made to the analysis of experimental data for the translational and rotational coefficients of DNA fragments with up to 103 base pairs, obtaining the persistence length for each model. The values for the wormlike chain agree well with model-independent values obtained from radii of gyration and with other literature data at varying ionic strength. The randomly broken chain is equally able to reproduce the experimental length dependence of the properties, but the resulting persistence length may be too high.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Four fractions of poly(vinyl chloride) (PVC) having appreciably different tacticity distributions were prepared by selective extractions on samples polymerised at temperatures between +60 and -50°C. They were degraded thermally at 180°C in the solid state to conversions in the range 0,2 to 0,5% and in solution at 200°C to conversions in the range 1,6 to 5%. The polyene sequence distribution was investigated by ultra violet/visible (UV/VIS) and resonance Raman spectroscopy. The results show that the type of polyene sequence distribution depends markedly on the tacticity distribution of the polymer. Cross-linking reactions occur more readily as the syndiotacticity increases. The results are discussed and interpreted with reference to previous work relating degradation processes and tacticity.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 191 (1990), S. 281-287 
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The molecular species proposed for the initial steps in the cationic polymerization of alkenylfurans were modeled by MNDO theoretically fully optimized structures. It was confirmed that the anomalous reactivity of ring C-5 of the monomers is determined by HOMO electron densitites, whereas calculated proton affinities from the semiempirical heats of formation fail to explain the low temperature experimental behavior of 2-vinylfuran (1c) from the point of view of stability of intermediate species. However, ab initio 4-31G calculations of proton affinities agree with the experimental facts and allow further explanations of the reactivity of furan derivatives in electrophilic media.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Poly(hydroxy ether of Bisphenol-A), so-called Phenoxy resin (structure-based IUPAC name: poly[oxy(2-hydroxytrimethylene)oxy-1,4-phenyleneisopropylidene-1,4-phenylene]), is shown to be miscible with poly(4-vinylpyridine) (P4VPy, poly[1-(4-pyridyl)ethylene]) and poly(2-vinylpyridine) (P2VPy, poly[1-(2-pyridyl)ethylene]) over the entire composition range. Miscibility of the blends is evidenced by their glass transition temperatures being intermediate between the pure polymers for the blends of P4VPy and Phenoxy but being higher than the average for the case of the P2VPy/Phenoxy blends. Hydrogen bonding between the components was detected through infrared spectroscopy, which was also used in the study of mixtures of low-molecular-weight analogues, in order to calculate the free energies of mixing according to the association model of Painter and Coleman.
    Additional Material: 8 Ill.
    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...