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
  • Springer  (885)
  • Oxford University Press  (430)
  • 2010-2014  (695)
  • 1995-1999  (607)
  • 1955-1959  (13)
Collection
Years
Year
  • 11
    ISSN: 1572-817X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Notes: Abstract The polarization dynamics of a dual-frequency, nearly isotropic He-Ne laser in the presence of weak anisotropic feedback were studied. Depending on the location of the perturbed mode under the gain curve, three distinctive hysteresis characteristics were observed. These hysteresis characteristics are distinguished by the height and width of the corresponding hysterograms. These switching dynamics are explained qualitatively in terms of the stability analysis of Lamb's multimode laser theory.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 12
    Electronic Resource
    Electronic Resource
    Springer
    Journal of inorganic and organometallic polymers and materials 5 (1995), S. 377-390 
    ISSN: 1572-8870
    Keywords: Hydrosilylation ; cyclodextrin ; platinum catalyst ; silicone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The Command-Cure concept is defined for a curable formulation as one with long work-like at ambient temperature and rapid cure time at elevated temperature. This concept is explored for a curable silicone system, cured via hydrosilylation. CODMCl2 complexes (COD=1.5-cyclo-octadiene:M=Pt. Pd) are reacted with beta-cyclodextrin (β-CD) to make 1∶1 inclusion compounds,M=Pd.2;M=Pt.4. Compounds2 and4 were analyzed by1H NMR and X-ray powder diffraction. Their catalytic ability was evaluated in a model system as well as a polymeric system that gels upon cure. Surprisingly, the Pd analog2 was a good command-cure catalyst whereas the guest compound CODPdCl2,1, was not active in the hydrosilylation reaction. The Pt analog,4, was an effective command-cure catalyst while the corresponding guest. CODPtCl2,3, was too active at low temperature in the hydrosilylation reaction. Additional Pt compounds and one Rh inclusion compound were evaluated as command cure catalysts. These inclusion compounds were: 1∶1 β-CD:[CODRhCl]2,5: 1∶1 β-CD:CpPtMe3,6 (Cp=cyclopentadienyl): 1∶2 β-CD:MeCpPtMe3,7; 1∶2 β-CO:CODPtMe2,8. The effectiveness of4 8 was evaluated in a number of silicone systems.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 13
    ISSN: 1572-8900
    Keywords: Biodegradation ; compost ; epoxy-based polyester
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Energy, Environment Protection, Nuclear Power Engineering , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract An epoxy-based thermoplastic polyester, poly(hydroxy ester ether), was incubated under aerobic conditions in a laboratory-scale compost system for 168 days to evaluate its potential for biodegradation. Radiolabeled test polymer [uniformly 14C ring-labeled, poly(hydroxy ester ether)] was incorporated into a mature compost and a sludge-amended compost at a loading of ∼3 mg test polymer/g compost. 14C-Cellulose was used as the positive control and a biologically inhibited control reactor was used to assess abiotic degradation of the test polymer. Degradation of the test polymer was assessed by measuring the amount of 14C-CO2 from each of the test reactors. In addition, at selected time intervals subsamples of the compost were collected and serially extracted with water, methanol, and dimethylformamide to monitor degradation of the 14C-test polymer and provide a partial characterization of the degradation intermediates. Extensive degradation of 14C-poly(hydroxy ester ether) was observed in the test reactors with degradation half-life of the parent polymer (t 1/2) of approximately 32 days. By the end of the study, only 2% of the total 14C activity in the test reactors was attributed to intact polymer, with most of the measurable 14C activity converted to either 14C-CO2 (26% of total 14C activity) or nonextractable products (accounting for ∼60% of the total activity). In contrast to the test reactors, only 3% of the 14C-poly(hydroxy ester ether) added to the biologically inhibited control reactor was mineralized to 14C-CO2. The results obtained from the microbially active and biologically inhibited compost systems indicate that the poly(hydroxy ester ether) polymer was degraded, at least in part, by a biologically mediated process.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 14
    Electronic Resource
    Electronic Resource
    Springer
    Journal of applied electrochemistry 29 (1999), S. 75-80 
    ISSN: 1572-8838
    Keywords: molybdenum nitride electrodes ; capacitors ; H2SO4electrolytes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Electrical Engineering, Measurement and Control Technology
    Notes: Abstract The electrochemical stability of polycrystalline thin film MoxN (x=1 and 2) electrodes deposited on previously nitrided polycrystalline Ti and bare Ti substrates and exposed to 4.4m H2SO4 electrolyte has been investigated. The electrodes were prepared by a temperature programmed procedure involving the reaction of MoO3 films and NH3. Cyclic voltammetry and a.c. impedance spectroscopy indicated that the range of electrochemical voltage stability in the electrolyte of the MoxN films on nitrided Ti substrates, referenced to a standard hydrogen electrode to be −0.01 to+0.69V. These electrodes had a calculated capacitance of about 315Fcm−3. The MoxN films on Ti substrates were electrochemically stable from −0.01 to +0.67V; however, they contained unconverted MoO2 which acted to reduce the calculated capacitance to about 210Fcm−3. At and above +0.70V and +0.68V on nitrided Ti and Ti substrates, respectively, an electrochemical reaction occurred. The formation of an amorphous phase in the reacted MoxN films was indicated by X-ray diffraction (XRD). Secondary ion mass spectroscopy (SIMS) showed increases in the atomic concentrations of hydrogen, oxygen and sulfur in the reacted films. The voltage bias applied to the electrodes influenced the chemical composition of the reacted films.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 15
    ISSN: 1572-8854
    Keywords: structure ; thiosemicarbazide ; infrared ; nmr ; hydrogen-bonding
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract The structures of two thiosemicarbazones are described: syn,E-1-cyclopentano-4-ethyl-3-thiosemicarbazone (1) and syn,E-1-cyclopentano-4-phenyl-3-thiosemicarbazone (2). Crystal data: for 1: tetragonal, P43 (#78), a = b = 8.922(7) Å, c = 12.899(13) Å, and Z = 4; for 2: monoclinic a = 15.163(18) Å, b = 7.482(5) Å, c = 12.467(15) Å, β = 119.04(7)°, and Z = 4. In 1, molecules are linked by hydrogen-bonding into infinite chains with non-planar 9-ring subunits in which thioamides interact with the H—N—C—N—N groups of neighbors. Thioamide groups in 2 form dimers linked by N—B···HS hydrogen-bonds with a planar 8-ring as in solid state structures of carboxylic acids. The semicarbazide syn conformation fosters formation of N—H···N intramolecular hydrogen-bonding in each structure. The solid state structures are consistent with their infrared and proton nuclear magnetic resonance spectra.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 16
    ISSN: 1572-8757
    Keywords: binary adsorption ; micropores ; nanopores ; molecular simulation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Physics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Monte Carlo and molecular dynamics simulations are performed to study fluid adsorption of a two component fluid in slit pores of nanoscopic dimensions. The slit pores are immersed in a binary fluid bath, which is comprised of spherical molecules having a size ratio of 1.43, at constant temperature and composition. Pore width is varied to determine how the heat capacity and self-diffusion coefficient are linked to the composition and structure of the adsorbed fluid. In pores where the fluid structure is most pronounced, we observe: perfect (or near perfect) exclusion of one component by the other component, a heat capacity that rapidly oscillates and is of greater magnitude than in the fluid bath, and self-diffusion coefficients on the order of 10−8 cm2/s. The behavior of the heat capacity and diffusion coefficients appears to arise from a near solid-like layering of OMCTS that occurs at certain favorable pore widths.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 17
    Electronic Resource
    Electronic Resource
    Springer
    Adsorption 2 (1996), S. 9-21 
    ISSN: 1572-8757
    Keywords: nanopores ; zeolites ; Monte Carlo simulations
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Physics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract A Grand Canonical Monte Carlo simulation method is used to determine the adsorption isotherms, interaction energies, entropies, and density distribution of a Lennard-Jones fluid adsorbed in smooth-walled nanopores of varying size and shape. We specifically include very crowded pores, where packing effects are important. Differences in the isotherms of slit, cylindrical, and spherical nanopores of varying sizes can be explained in terms of the adsorbate-adsorbate interaction energy, the adsorbate-pore interaction energy, and the density profiles, which influence the balance between the former and the latter energy contributions. The expectation from low loading studies that the most energetically favorable adsorbate-pore interactions maximize adsorption is not borne out at intermediate and higher loadings. Instead, the relationships between adsorbed amounts and pore size and shape are found to be strong functions of the depth and steepness of the external potential, the extent to which adsorbate-adsorbate repulsion establishes short range fluid order, and the accessible pore volume. This study has implications for high pore density processes in nanoporous materials, such as zeolite catalysis, separations, and templating in zeolite synthesis.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 18
    Electronic Resource
    Electronic Resource
    Springer
    Catalysis letters 36 (1996), S. 51-57 
    ISSN: 1572-879X
    Keywords: sulfated metal oxides ; sulfated zirconia catalyst ; Brønsted acidity ; catalytic activity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The thermal decomposition products of pyridinium sulfate differ from those of pyridinium sulfate supported on zirconia which in turn differs from that of pyridine adsorbed on a sulfated zirconia. Unsupported pyridinium sulfate decomposes to produce pyridine and sulfuric acid, and these subsequently react to produce oxides of carbon and sulfur. Zirconia that is sulfated and then exposed to pyridine does not release detectable amount of pyridine during heating in an inert gas; rather the pyridine undergoes oxidation reduction reactions simultaneously to release CO2 and sulfur compounds. Pyridinium sulfate supported on zirconia decomposes upon heating to release pyridine and sulfuric acid, which reacts with the zirconia. The desorption of pyridine in one case and only CO2/SOx in the other case suggests that sulfated zirconia does not contain Brønsted acidity that can form pyridinium sulfate.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 19
    ISSN: 1572-879X
    Keywords: ETS-10 ; TS-1 ; Ti-β ; EXAFS ; XANES ; X-ray ; UV ; methanol ; 2-propanol
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract We report here the first structural characterization by Ti K-edge EXAFS and XANES of ETS-10 and aluminum-free Ti-β molecular sieves. A TS-1 sample was also studied for comparison. The near-edge spectrum of TS-1 revealed an intense pre-edge feature characteristic of Ti atoms in tetrahedral coordination. However, the pre-edge peak for ETS-10 was quite small and shifted in energy, which is consistent with the known octahedral structure surrounding Ti atoms in the material. Analysis of the EXAFS for ETS-10 revealed an average Ti-O interatomic distance of 2.00 +- 0.01 Å which is longer than the Ti-O distance (1.95Å) in anatase TiO2. For Ti-β, an intense pre-edge peak is present in the near-edge spectrum and the intensity, energy and width of this peak are the same as for TS-1. In addition, the average Ti-O interatomic distance in Ti-β and TS-1 was 1.80 +- 0.01 Å, which is significantly shorter than the distance measured in ETS-10. The EXAFS and XANES results indicate that the Ti sites in aluminum-free Ti-β are structurally identical to the tetrahedral sites in TS-1. This conclusion is supported by the similarity of the UV absorption thresholds for the two samples. X-ray absorption spectra were also recorded with methanol or 2-propanol adsorbed on the Ti-β and TS-1 molecular sieves. Alcohol adsorption decreased the intensity and broadened the Ti pre-edge peak for both samples, demonstrating a local chemical interaction with the Ti sites. Methanol adsorption lengthened the average Ti-O bond to 1.83 ± 0.01 Å. The similarity of the X-ray absorption spectra for aluminum-free Ti-β and TS-1 in the presence of alcohols suggests that the Ti sites in the two frameworks are chemically indistinguishable for vapor-phase adsorption of alcohols at low concentrations.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 20
    Electronic Resource
    Electronic Resource
    Springer
    Journal of theoretical probability 8 (1995), S. 693-701 
    ISSN: 1572-9230
    Keywords: Central limit theorem
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics
    Notes: Abstract We give an elementary proof of the local central limit theorem for independent, non-identically distributed, integer valued and vector valued random variables.
    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...