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
  • 1
    Electronic Resource
    Electronic Resource
    Spiral growth of InGaN/InGaN quantum wells due to Si doping in the barrier layers (1999)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 74 (1999), S. 1153-1155 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We have examined Si-doping effects in InGaN/InGaN quantum-well (QW) structures, especially the influence of Si-doped InGaN barrier layers on the growth mechanism of QW structures, by atomic force microscopy (AFM) and by photoluminescence (PL) and cathodoluminescence (CL) spectroscopy. Our AFM observations revealed that Si-doped InGaN barriers strongly affect the growth mode of overlying InGaN QW layers. This effect leads to the formation of nanoscale islands (with a density of 108 cm−2) due to spiral growth of the QW layers. The spirally grown nanoscale islands significantly increase the PL intensity. Through spatially resolved CL observations, we found that the number of dot-like CL bright spots increased dramatically when the barrier layers were Si doped, and the increased density of the spots was in good agreement with the increased density of the nanoscale islands observed by AFM. By combining these results, we show that the spirally grown QW structures produced by Si doping of the barriers effectively reduce the fluctuation of the band-gap potential in InGaN QW layers. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.123471
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Superconvergence of numerical solutions to weakly singular Volterra integro-differential equations (1992)
    Springer
    Numerische Mathematik 61 (1992), S. 373-382 
    Details
    ISSN: 0945-3245
    Keywords: 65R20 ; 45D05
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics
    Notes: Summary We discuss the application of a class of spline collocation methods to first-order Volterra integro-differential equations (VIDEs) which contain a weakly singular kernel (t−s)−α with 0〈α〈1. It will be shown that superconvergence properties may be obtained by using appropriate collocation parameters and graded meshes. The grading exponents of graded meshes used are not greater thanm (the polynomial degree) which is independent of α. This is in contrast to the theories of spline collocation methods for Volterra (or Fredholm) integral equation of the second kind. Numerical examples are given to illustrate the theoretical results.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01385515
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Relationship between Palladium Morphology and Thermodynamics in Palladium-Hydrogen System (2005)
    s.l. ; Stafa-Zurich, Switzerland
    Materials science forum Vol. 475-479 (Jan. 2005), p. 2485-2488 
    Details
    ISSN: 1662-9752
    Source: Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: The pressure-composition (P-C) isotherms of protium and deuterium in Pd sponge particles have been measured over a temperature range from 278K to 323K. Based on these data and combined with literature data, the relationship between the Pd crystal type, particle size and thermodynamic properties in the Pd-H system was investigated. The saturation solubility of hydrogen in solid solutionregion ( a-phase) and the absorption plateau pressure increase with the decreasing Pd particle size at ambient temperature, but the desorption plateau pressure does not change with Pd morphology. The effect of Pd morphology on above two parameters gets weaker at higher temperature and the difference of plateau pressure among several different Pd morphologies disappears at highertemperature, such as 373K. The absolute value of phase transformation enthalpy and entropy from solid solution phase to hydride phase decrease with the decreasing particle size of Pd, but which are the smallest in single crystal Pd. The degree of hysteresis effect in Pd-H system depends on the background density in the sample, so it is the strongest in Pd sponge
    Type of Medium: Electronic Resource
    URL: http://www.tib-hannover.de/fulltexts/2011/0528/02/09/transtech_doi~10.4028%252Fwww.scientific.net%252FMSF.475-479.2485.pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Convergence of MUSCL Relaxing Schemes to the Relaxed Schemes for Conservation Laws with Stiff Source Terms (2000)
    Springer
    Journal of scientific computing 15 (2000), S. 173-195 
    Details
    ISSN: 1573-7691
    Keywords: relaxation scheme ; nonlinear conservation laws ; maximum principle ; convergence
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract We consider the convergence and stability property of MUSCL relaxing schemes applied to conservation laws with stiff source terms. The maximum principle for the numerical schemes will be established. It will be also shown that the MUSCL relaxing schemes are uniformly l 1- and TV-stable in the sense that they are bounded by a constant independent of the relaxation parameter ε, the Lipschitz constant of the stiff source term and the time step Δt. The Lipschitz constant of the l 1 continuity in time for the MUSCL relaxing schemes is shown to be independent of ε and Δt. The convergence of the relaxing schemes to the corresponding MUSCL relaxed schemes is then established.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1007681726414
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Fractionated crystallization in polyolefins-nylon 6 blends (1994)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 53 (1994), S. 355-360 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: The crystallization behavior of polyolefins-nylon 6 polymer blends was studied by differential scanning calorimetry (DSC) measurements. In these blends, the crystallization of the minor component often starts with distinctly deeper supercooling than that of the pure polymer, and proceeds in several separate steps. The origin of this phenomenon was studied and was related to the volume fraction of the dispersed phase and the compatibility between the dispersed phase and the matrix. © 1994 John Wiley & Sons, Inc.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1994.070530313
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Compatibilizing effect of polystyrene-block-poly(4-vinylpyridine) for poly(2,6-dimethyl-1,4-phenylene oxide)/chlorinated polyethylene blends (1998)
    Weinheim : Wiley-Blackwell
    Macromolecular Chemistry and Physics 199 (1998), S. 2625-2630 
    Details
    ISSN: 1022-1352
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The compatibilizing effect and mechanism of compatibilization of the diblock copolymer polystyrene-block-poly(4-vinylpyridine) P(S-b-4VPy) on immiscible blends of poly(2,6-dimethyl-1,4-phenylene oxide) (PPO)/chlorinated polyethylene (CPE) were studied by means of scanning electron microscopy (SEM), differential scanning calorimetry (DSC), mechanical properties and FTIR measurements. The block copolymer was synthesized by sequential anionic polymerization and melt-blended with PPO and CPE. The results show that the P(S-b-4VPy) added acts as an effective compatibilizer, located at the interface between the PPO and the CPE phase, reducing the interfacial tension, and improving the interfacial adhesion. The tensile strength and modulus of all blends increase with P(S-b-4VPy) content, whereas the elongation at break increases for PPO-rich blends, but decreases for CPE-rich blends. The polystyrene block of the diblock copolymer is compatible with PPO, and the poly(4-vinylpyridine) block and CPE are partially miscible.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 7
    Electronic Resource
    Electronic Resource
    Synthesis of a polyethylene-graft-polystyrene copolymer and its compatibilization for linear low density polyethylene/poly(phenylene oxide) blendsThis work is supported by the National Natural Foundation of China. (1995)
    Weinheim : Wiley-Blackwell
    Macromolecular Chemistry and Physics 196 (1995), S. 2173-2182 
    Details
    ISSN: 1022-1352
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Based on unsteady diffusionkinetics, polyethylene(PE)-graft-polystyrene (PS) copolymers were designed and synthesized with a heterogeneous high yield titanium-based catalyst by copolymerization of ethylene with a PS-macromonomer using 1-hexene as a short main agent to promote the incorporation of the PS-macromonomer. The presence of 1-hexene facilitated the diffusion of the PS-macromonomer, giving rise to the significantly increased incorporation of the PS-macromonomer. Compatibilization of blends of linear low density polyethylene (LLDPE)/poly(phenylene oxide) (PPO) with the PE-g-PS copolymer were investigated using scanning electron microscopy (SEM) and dynamic mechanical analysis (DMA).
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1995.021960708
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Compatibilization and structure of poly(propylene)/nylon-12 blends (1994)
    Weinheim : Wiley-Blackwell
    Macromolecular Chemistry and Physics 195 (1994), S. 2931-2945 
    Details
    ISSN: 1022-1352
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: In this paper, scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and wide-angle X-ray diffraction (WAXD) were used to study the structure and compatibilization of poly(propylene) (PP)/nylon-12 (PA 12) blends. The compatibilization of maleated PP(PP-MA) and graft copolymer (PP-MA-g-PEO) of PP-MA and poly(ethylene oxide) (PEO) in PP/PA 12 blends was observed from the morphology of the fracture surface of PP/PA12 blends. The compatibilization mechanism was investigated. The DSC results showed that there was nucleation between PP and PA12. This was attributed to the unusual epitaxial relationship. The effect of PA12 on the crystalline structure of PP was studied by means of WAXD.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1994.021950821
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Compatibilization of polypropylene/poly (ethylene oxide) blends and crystallization behavior of the blends (1994)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part B: Polymer Physics 32 (1994), S. 1991-1998 
    Details
    ISSN: 0887-6266
    Keywords: polypropylene (PP) ; blend ; compatibilization ; crystallization ; fractionated crystallization ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The compatibilization of incompatible polypropylene (PP)/poly(ethylene oxide) (PEO) blends was studied. The experimental results showed that the graft copolymer [(PP-MA)-g-PEO] of maleated PP(PP-MA) and mono-hydroxyl PEO (PEO-OH) was a good compatibilizer for the PP/PEO blends in which PP-MA also had some compatibilization. The crystallization of the blends was affected by the compatibility between PP and PEO. The interfacial behavior of the compatibilizers had an important effect on crystallization behavior of the PP/PEO blends. PEO showed fractionated crystallization in the PP/PEO blends. This behavior was studied from the view point of the theory of fractionated crystallization. © 1994 John Wiley & Sons, Inc.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/polb.1994.090321205
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Compatibilization of high density polyethylene/polyisoprene blends with polyethylene/polyisoprene “thread-through” copolymersThis work was supported by the National Natural Science Foundation of China. (1995)
    Weinheim : Wiley-Blackwell
    Macromolecular Chemistry and Physics 196 (1995), S. 3585-3595 
    Details
    ISSN: 1022-1352
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The compatibilization of high density polyethylene (HDPE)/polyisoprene (PI) blends with polyethylene/polyisoprene (PE/PI) “thread-through” copolymers was investigated. The proliferating structure of PE/PI with segments chemically identical to HDPE and PI, respectively, is different from that of graft copolymers. Studies showed that the dispersed domain size in the blends was significantly reduced and interfacial adhesion was improved by the compatibilization action of the copolymer. In the differential scanning calorimetry (DSC) analysis, the crystallization peak of HDPE in the blends became broad with adding the copolymer and fractionated crystallization appeared in the HDPE/PI blend compatibilized with the copolymer at a weight ratio of 30/70 while it appeared in the blend without copolymer at a weight ratio of 20/80. DMA results showed that by adding the copolymer, both the glass transition temperature (Tg) of the PI component and the a- relaxation of HDPE shifted to lower temperature, demonstrating the enhanced penetration of the two components. Mechanical properties of the blends were improved, especially the elongation at break, by the presence of the copolymers. The characteristic yielding at the fractured surface of the blends compatibilized with the copolymer indicates the fractural behavior of the material changed from brittle to tough.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1995.021961112
    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...