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
  • Chemistry  (28)
  • General Chemistry  (4)
  • Life and Medical Sciences  (2)
  • 78.20.Dj  (1)
  • AMS(MOS)  (1)
  • 1985-1989  (19)
  • 1970-1974  (13)
Collection
Keywords
Publisher
Years
Year
  • 1
    Electronic Resource
    Electronic Resource
    An algorithm to compute a sparse basis of the null space (1985)
    Springer
    Numerische Mathematik 47 (1985), S. 483-504 
    Details
    ISSN: 0945-3245
    Keywords: AMS(MOS) ; 65F30 ; CR: G1.3
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics
    Notes: Summary LetA be a realm×n matrix with full row rankm. In many algorithms in engineering and science, such as the force method in structural analysis, the dual variable method for the Navier-Stokes equations or more generally null space methods in quadratic programming, it is necessary to compute a basis matrixB for the null space ofA. HereB isn×r, r=n−m, of rankr, withAB=0. In many instancesA is large and sparse and often banded. The purpose of this paper is to describe and test a variation of a method originally suggested by Topcu and called the turnback algorithm for computing a banded basis matrixB. Two implementations of the algorithm are given, one using Gaussian elimination and the other using orthogonal factorization by Givens rotations. The FORTRAN software was executed on an IBM 3081 computer with an FPS-164 attached array processor at the Triangle Universities Computing Center and on a CYBER 205 vector computer. Test results on a variety of structural analysis problems including two- and three-dimensional frames, plane stress, plate bending and mixed finite element problems are discussed. These results indicate that both implementations of the algorithm yielded a well-conditioned, banded, basis matrixB whenA is well-conditioned. However, the orthogonal implementation yielded a better conditionedB for large, illconditioned problems.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01389453
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Reduction of optical absorption at a wavelength of around 0.8 μm in LPE garnet (TmBiCa)3(FeGaPt)5O12 (1985)
    Springer
    Applied physics 38 (1985), S. 281-284 
    Details
    ISSN: 1432-0630
    Keywords: 78.20.Dj ; 68.55.+b ; 78.20.Ls
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract Liquid-phase epitaxy (LPE) garnet films (TmBiCa)3(FeGaPt)5O12 have been grown using only Bi2O3 as the flux so that the film containing Bi gives high specific Faraday rotation. The film does not contain Pb, which may affect optical absorption. The optical absorption coefficientα at 810 nm has been effectively reduced by doping Ca in the melt. Our data show that a minimum level ofα and of the anisotropy constantK u and also the maximum of the electrical resistivityϱ are achieved when Ca2+ replaces Fe2+. Fe2+ results from Pt4+ incorporation in the film due to a Bi2O3 flux attack on a Pt crucible. Using a compensated film,α of 58 cm−1 and a figure of merit of 9deg/dB were obtained.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00616064
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Incorporation of a well-defined polyether side-chain into segmented poly(ether-urethane urea) and examination for blood-compatibility (1989)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 172 (1989), S. 177-183 
    Details
    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: Es wird eine neue Methode zur Einführung von hydrophilen Polyetherseitenketten in segmentierte Polyurethane unter Verwendung eines Polypropylenoxid-Macromeren mit 1,3-Diol-Gruppen an einem Kettenende, die als Kettenverlängerer fungieren, beschrieben. In diesem Prozeß wird eine Seitenkette quantitativ und direkt in medizinische Polyurethanelastomere eingebaut. Diese Entwicklung ist auch für Biowerkstoffe in künstlichen Organen von Interesse.
    Notes: A new method of introducing a hydrophilic polyether side chain into segmented polyurethane using a polypropylene oxide macromer with 1,3-diol at one chain-end, which behaves as chain extender, is described. In this procedure, a molecular-designed side-chain is incorporated quantitatively and directly into polyurethane biomedical elastomer. The design is also of interest to biomaterials in artificial organs.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/apmc.1989.051720115
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    The catalytic effects of the poly(vinylpyridine)-ligand in the oxidative polymerization of phenols (1973)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 164 (1973), S. 203-213 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Um die katalytische Wirkung des Polymer-Liganden zu untersuchen, wurden Kupfer-Poly(vinylpyridin) (Cu-PVP)-Komplexe als Katalysatoren für die oxydative Polymerisation der Phenole eingesetzt. Der Katalyseverlauf wurde diskutiert.Die mit dem Cu-PVP-Komplex katalysierte Polymerisation des 2,6-Dimethylphenols verlief langsamer als die mit dem Kupfer-Pyridin-Komplex katalysierte. Aufgrund der Messung der kinetischen Konstanten wurde angenommen, daß der raumfüllende PVP-Ligand die Koordination des Monomeren zum Metall stört. Die Polymerisation des Monomerengemisches aus XOH und o-Kresol verlief in Gegenwart des Cu-PVP-Katalysators bei höheren Umsätzen mit konstanter Geschwindigkeit. Die Ausbeute und das Molekulargewicht des erhaltenen Polymeren waren größer als in den Fällen, in denen Cu-Pyridinoder Cu-γ-Pikolin-Komplexe als Katalysatorsysteme verwandt wurden. XOH wird vorzugsweise mit dem Cu-PVP-Katalysator aktiviert, da das Oxydationspotential des XOH niedriger ist; dadurch wird die Wirkung des PVP-Liganden erfaßbar.
    Notes: In order to study the catalytic effects of the polymer-ligand, copper-poly(vinylpyridine) (Cu-PVP) complexes were used as catalyst for the oxidative polymerization of phenols. The catalysis was discussed.The rate of the 2,6-dimethylphenol (XOH) polymerization catalyzed by the Cu-PVP complex was slower than that catalyzed by a Cu-pyridine complex. By the measurement of the kinetic constants, it was suggested that a bulky PVP ligand obstructed the coordination-step of the monomer and the electron-transfer-step from the coordinated monomer to the cupric ion. The polymerization of the mixture of XOH and o-cresol with Cu-PVP as catalyst was saturated at a higher conversion, and the yield and the molecular weight of the polymer obtained were larger than in the cases where the Cu-pyridine or the Cu-γ-picoline complex systems were used as catalysts. XOH is preferentially activated by the Cu-PVP catalyst because its oxidation potential is lower, thus the effect of the PVP ligand may be observed.XOH was polymerized by the swelled Cu-PVP complex as a heterogeneous catalyst in benzene or a benzene containing mixture of solvents. The catalyst was recovered by filtration in a high yield and re-used repeatedly. Cu-PVP complexes are relatively stable toward alkali because of their chelate structure. The polymerization was accelerated 3 to 5 times in alkaline solution, and the side-reaction was suppressed.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1973.021640119
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Oxidative polymerization of 2,6-dimethylphenol with semiconducting organic polymeric metal complexes containing the bis(ethylene-1,2-dithiolato)copper (II) structure, 1 (1974)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 175 (1974), S. 2795-2809 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Die katalytische Aktivität bei der oxidativen Polymerisation von 2,6-Dimethylphenol (8) der folgenden halbleitenden organischen polymeren Metallkomplexe wurde untersucht: polymere Komplexe, die gleichzeitig Bis(äthylen-1,2-dithiolo)Cu(II)- oder Fe(III)-Komplexe und Cu(II)-Phthalocyanin-Strukturen (3a-c) enthalten bzw. die gleichzeitig Bis(äthylen-1,2-dithiolo)Cu(II)- oder Fe(III)-Komplex- und Hemiporphyrazin-Strukturen (5a-c) aufweisen, und Koordinationskomplexe, die sich aus Dimercaptomaleinsäuremonoamid (7) aufbauen lassen. Es wurde gefunden, daß eine Suspension der unlöslichen polymeren Cu-Komplexe vom Typ 3 in Gegenwart von Sauerstoff die oxidative Polymerisation bei Raumtemperatur katalysiert und daß Poly[oxy(2,6-dimethyl-1,4-phenylen)] (9) in sehr guter Ausbeute entsteht. Polymere Komplexe vom Typ 5 waren für sich allein inaktiv. Eine wesentlich erhöhte Aktivität zeigten die polymeren Komplexe vom Typ 3 und 5 in Gegenwart von wenig Cu(II)-Pyridin-Komplex in Pyridin-Lösung. (Die zugesetzten Mengen waren so niedrig, daß Cu(II)-Pyridin allein nur eine geringe Aktivität aufweis.) Polymere Komplexe mit Bis(äthylen-1,2-dithiolo)Fe(III)-Strukturen waren auch in Anwesenheit des Cu(II)-Pyridin-Komplexes inaktiv.
    Notes: In the oxidative polymerization of 2,6-dimethylphenol (8) the catalytic activities of the following semiconducting organic polymeric metal complexes were studied: polymeric complexes containing bis(ethylene-1,2-dithiolato)Cu(II) or Fe(III) complexes and copper(II) phthalocyanine structures (3a-c), catalysts consisting of bis(ethylene-1,2-dithiolato)-Cu(II) or Fe(III) complex structures and hemiporphyrazine type structures (5a-c), and also polymers containing a copper complex of dimercaptomaleic acid monoamide (7). It was found that a suspension of the insoluble bis(ethylene-1,2-dithiolato)Cu(II) polymeric complexes of type 3 catalyzes the polymerization in the presence of oxygen in pyridine at room temperature producing poly[oxy-(2,6-dimethyl-1,4-phenylene)] (9) in very good yields. Polymeric complexes of type 5 were inactive by themselves. However, we showed that bis(ethylene-1,2-dithiolato)Cu(II) polymeric complexes of both the 3 and 5 type possess great activities if they are used in the presence of small amounts of copper(II)-pyridine complex in pyridine solution (the chosen concentration was so low that the Cu(II)-pyridine complex alone had only a small activity). Bis(ethylene-1,2-dithiolato)Fe(III) complexes of both the 3 and 5 type were inactive even in the presence of the Cu(II)-pyridine complex.
    Additional Material: 5 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1974.021751002
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Dioxygen sensitivity of a photoexcited thin film of phthalocyanine dispersed in poly(N-vinylcarbazole) (1988)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 189 (1988), S. 2419-2423 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Thin films (thickness 0,3 μm) of a mixture of phthalocyaninatozinc(II) (1) and poly(1-vinylcarbazole) (2) are prepared by coating from a solution on ITO glass. The blue coloured films are investigated in an electrochemical cell under irradiation with visible light. In the presence of dioxygen from air the films exhibit an intensive cathodic photocurrent. The action spectrum of the photocurrent corresponds to the absorption spectrum of the phthalocyanine. The results show a device which can be switched by air and visible light.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1988.021891019
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Oxidative polymerization of 2,6-dimethylphenol with semiconducting organic polymeric metal complexes containing the bis(ethylene-1,2-dithiolato)-copper(II) structure, 2Part 1: cf.1. (1974)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 175 (1974), S. 2811-2820 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Wird der unlösliche polymere Komplex 1, der Bis(äthylen-1,2-dithiolo)Cu(II) und Cu(II)Phthalocyanin-Strukturen aufweist, mit einer Pyridinlösung niedriger Konzentration an Kupfer(II)-Pyridin Komplex behandelt, erhält man ein Filtrat mit hoher katalytischer Aktivität für die oxidative Polymerisation des 2,6-Dimethylphenols. Dabei wird der polymere Komplex partiell zersetzt und damit partiell gelöst. Die katalytische Wirkung des gelösten Teils des Komplexes 1 wurde untersucht. Dieses gemischte Katalysatorysystem aus Cu(II)Py und dem gelösten Teil von 1 ist unter den hier untersuchten Bedingungen 6-50fach aktiver als der Cu(II)Py-Komplex allein.
    Notes: If an insoluble polymeric complex 1 which possesses both the bis(ethylene-1,2-dithiolato)Cu(II) a Cu(II)phthalocyanine type structure is treated with a pyridine solution of the Cu(II)-pyridine complex in a low concentration, the filtrate obtains a high activity for the oxidative polymerization of 2,6-dimethylphenol. This might be due to a partial decomposition followed by a partial dissolution of the polymer complex. The catalytic behaviour of the soluble part of the polymeric complex 1 was studied. The activity of this mixed catalyst system consisting of Cu(II)Py and the soluble part of 1 was found to be 6-50times higher than that of Cu(II)Py alone under the applied conditions.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1974.021751003
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    New catalysts for the oxidative polymerization of 2,6-dimethylphenol. Bis(1,2-dicyanoethylene-1,2-dithiolato)cuprate(2-) complexes (1974)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 175 (1974), S. 3401-3410 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Die katalytische Aktivität verschiedener Bis(1,2-dicyanoäthylen-1,2-dithiolato)-Metall-Komplexe (1a-f) wurde untersucht. Es wurde gefunden, daß Kupferbis(1,2-dicyanoäthylen-1,2-dithiolato)cuprat(2-) (1a) die oxidative Polymerisation des 2,6-Dimethylphenols in Anwesenheit von molekularem Sauerstoff katalysiert. Unter gewissen Polymerisationsbedingungen ist dieser Katalysator viel aktiver als der bekannte Kupfer(II)-Pyridin-Komplex.
    Notes: The catalytic activities of various bis(1,2-dicyanoethylene-1,2-dithiolato)metal (1a-f) complexes were investigated. It was found that copper bis(1,2-dicyanoethylene-1,2-dithiolato)cuprate(2-) (1a) catalyzes the oxidative polymerization of 2,6-dimethylphenol in the presence of molecular oxygen. At some polymerization conditions this catalyst is much more active than the well-known copper(II)-pyridine complex.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1974.021751206
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Quenching of the excited state of membranes having polymerpendant tris(2,2′-bypyridine)ruthenium(II) groups by methylviologen and dioxygen (1987)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 188 (1987), S. 2011-2017 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Quenching of the excited state of copolymer-pendant Ru(bpy)2+3 membranes by methylviologen (MV2+) and dioxygen was studied and its application proposed. The copolymers used were the copolymer of styrene (St) and 4-methyl-4′-vinyl-2,2′-bipyridine (Vbpy) and that of methyl methacrylate (MMA) and Vbpy. The copolymer-pendant complexes were prepared by reaction of the St- and MMA-copolymers with cis-Ru(bpy)2Cl2. The excited state of the St-copolymer complex membrane was not quenched by MV2+ solution in aqueous medium, but quenched in methanol. The excited state of the MMA-copolymer complex membrane was not quenched by MV2+ neither in water nor in water/methanol mixture. The excited state of St-copolymer complex membrane was not quenched by dioxygen in water, but in methanol. The excited state of MMA-copolymer complex membrane was quenched by dioxygen both in water and water/methanol mixture. The quenching by dioxygen can be used to measure the oxygen concentration in solutions.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1987.021880823
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Quenching of photo-excited state of copolymer pendant Ru(bpy)32+ complexes with methylviologen (1986)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 24 (1986), S. 2749-2756 
    Details
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Copolymer pendant tris(2,2′-bipyridine)ruthenium(II) complexes were prepared from the copolymers of 4-methyl-4′-vinyl-2,2′-bipyridine with styrene, acrylic acid, methyl methacrylate, hydroxyethyl methacrylate, acrylonitrile, N-vinylpyrrolidone, 4-vinylpyridine, and quaternized 4-vinylpyridine. The quenching of the photo-excited state of the polymer complexes by methylviologen was studied. Pendant anionic groups such as acrylate enhanced remarkably the quenching of the cationic sensitizer by the cationic substrate, however, pendant cationic groups such as quaternized pyridine did not affect the reaction. The polymer chain showed generally retarding effect on the quenching reaction.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pola.1986.080241104
    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...