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
    Heteroepitaxy of GaP-Al"xGa"1"-"xP system by the Temperature Difference Method under Controlled Vapor Pressure (TDM-CVP)
    Amsterdam : Elsevier
    Journal of Crystal Growth 99 (1990), S. 297-301 
    Details
    ISSN: 0022-0248
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Chemistry and Pharmacology , Geosciences , Physics
    Type of Medium: Electronic Resource
    URL: http://linkinghub.elsevier.com/retrieve/pii/0022-0248(90)90531-O
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    A novel PWM scheme of voltage source inverters based on space vector theory (1990)
    Springer
    Electrical engineering 74 (1990), S. 33-41 
    Details
    ISSN: 1432-0487
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology
    Description / Table of Contents: Übersicht Es wird ein neues Modulationskonzept vorgeschlagen, mit dem die Oberschwingungsströme beträchtlich herabgesetzt werden können. Wie analytisch gezeigt wird, hängen diese von Amplitude und Phasenwinkel des Zeigers der Referenzspannung, der Wechselrichter-Ausgangsspannung in einer Schaltperiode und der Abfolge der Zeiger dieser Ausgangsspannung ab. Nach dem neuen Konzept wird die Schaltfolge so gewählt, daß sich ein Minimum der Oberschwingungsströme ergibt. In einer Versuchseinrichtung wird das Pulsmuster durch Software in Echtzeit generiert. Im Vergleich mit der konventionellen Sinusbewertung bestätigt sich eine Verminderung der Welligkeit und eine Verschiebung des Oberschwingungsspektrums in den Bereich höherer Frequenzen.
    Notes: Contents A novel PWM scheme which can considerably reduce harmonic currents is proposed. It is explained analytically that the harmonic currents depend on the amplitude and phase angle of the reference voltage vector, the inverter output voltage vectors used in a switching period, and the sequence of these output voltage vectors. In the novel PWM scheme, the switching sequence is selected so that the harmonic currents are minimum. An experimental system which generates the PWM patterns by software at real time is constructed. Compared with the conventional sinusoidal PWM scheme, it is confirmed that the current ripple is decreased and the spectrum is shifted and dispersed to a higher frequency region.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01573229
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Thermochromism of poly-1-butene gels (1988)
    Springer
    Colloid & polymer science 266 (1988), S. 688-691 
    Details
    ISSN: 1435-1536
    Keywords: Thermochromism ; poly-1-butene gel ; benzene ; xylene
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Poly-1-butene gels in some solvents of benzene-derivatives show a colouring phenomenon. The colour changes from blue to yellow under irradiation of natural light as the temperature rises from the melting point of the solvent to the sol-gel transition temperature. The colouring phenomenon is due to selective scattering, but not to optical absorption. The apparent characteristics of the phenomenon resemble the thermochromism of cholesteric liquid crystals, although poly-1-butene itself is colourless and has no asymmetric carbons.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01410277
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Adhesion of molded polyethylene using polyethylene gels by microwave heating (1990)
    Springer
    Colloid & polymer science 268 (1990), S. 28-30 
    Details
    ISSN: 1435-1536
    Keywords: Microwaveheating ; adhesion ; polyehtylene ; chlorobenzene ; 1,1,2,2-tetrachloroethane
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Adhesive effect of polyethylene gels on the molded polyethylene by heating with microwaves has been investigated. Polyethylene gels in polar organic solvents such aso-xylene, chlorobenzene,o-dichlorobenzene,m-dichlorobenzene, 1,1,1,2-tetrachloroethane, and 1,1,2,2-tetrachloroethane were used as adhesives. All of these gels showed adhesive effect when heated with microwaves. In particular, the gels in 1,1,2,2-tetrachloroethane showed such strong adhesion that polyethylene plates of 3 mm in thickness and 20 mm in width gave rise to necking by heating for 8 min in a 500 W (2450 MHz) microwave oven.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01410419
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Adhesive effect of low-density polyethylene gels on polyethylene moldings (1990)
    Springer
    Colloid & polymer science 268 (1990), S. 143-147 
    Details
    ISSN: 1435-1536
    Keywords: Adhesion ; gel ; decalin ; tetralin ; o-dichlorobenzene ; lowdensitypolyethylene
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Adhesive effect of low density polyethylene (LDPE) gels in organic solvents such as decalin, tetralin, ando-dichlorobenzene on high density polyethylene (HDPE) moldings has been investigated by shearing tests, electron microscopy, and DSC measurements. When heated at 110°C for 2 h, all of the gels showed strong adhesive strengths around 30 kg/cm2, which is sufficiently strong for practical uses. It has been found that the adhesive strength increases with the heating temperature and that the temperature at which the heated gel begins to exhibit the adhesive effect depends upon solvents and is about 30° lower than that of the HDPE gels.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01513192
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Lower critical solution temperature (LCST) and theta temperature of aqueous solutions of nonionic surface active agents of various polyoxyethylene chain lengths (1988)
    Springer
    Colloid & polymer science 266 (1988), S. 594-600 
    Details
    ISSN: 1435-1536
    Keywords: Lower critical solution temperature ; theta temperature ; nonionic surfactant ; conformation of polyoxyethylene chain ; phase separation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Cloud points of aqueous solutions of homogeneous poly(oxyethylene)dodecyl ether derivatives (C12(OE)n: n=2–8) and the apparent theta temperatureTθ ap were determined from the abrupt changes in optical transmittance and the temperature dependence of the second virial coefficient obtained by light scattering measurements. It was found that the lower critical solution temperature (LCST) shifts to a lower temperature and lower concentration as the number of oxyethylene units in a molecule decreases. Because of this behavior of LCST, the modified Flory-Schultz plot of phase separation was applied to the present nonionic surfactant-water system, and its theta temperature obtained. The dependence ofTθ ap on the number of oxyethylene units suggests that the polyoxyethylene chain has different effects on the solubility of C12(OE)n in water forn less than or equal to 3 from those forn greater than or equal to 4.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01411498
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Adsorption of polyethylene glycol from aqueous solution on montmorillonite clays (1989)
    Springer
    Colloid & polymer science 267 (1989), S. 899-906 
    Details
    ISSN: 1435-1536
    Keywords: Claymineral ; montmorillonite ; adsorption ; polyethyleneglycol ; watertreatment
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Adsorption rates and capacities of polyethylene glycol (PEG) were investigated for five montmorillonite clays. The adsorption of PEG for all the montmorillonite clays was rapid, and equilibrium was attained within 30 min. The adsorption isotherms of PEG for all the montmorillonites conformed to the Freundlich equation. The adsorption heats were 7.3 and 11.6 kJ · mol−1(mw.:2000), and 8.7 and 14.2 kJ · mol−1(mw.:20000) for the montmorillonite and the bentonite II-Ca, respectively. Adsorption capacities for all the clay samples approached constants for the molecular weight of PEG over 2000, though they increased with the increase of molecular weight under 2000. The adsorption capacities were slightly influenced by a nearly neutral pH. The montmorillonite clays which had different interlayer cations showed quite different adsorption capacities. The bentonite II-Ca, the acid clay, and the activated clay showed large adsorption capacities that were 30–50 % of that of an activated carbon.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01410338
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Adhesive effect of high density polyethylene gels on polyethylene moldings (1989)
    Springer
    Colloid & polymer science 267 (1989), S. 500-505 
    Details
    ISSN: 1435-1536
    Keywords: Adhesion ; gel ; decalin ; tetralin ; highdensitypolyethylene
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Adhesive effect of polyethylene moldings by use of high density polyethylene gels in organic solvents such as decalin, tetralin, ando-dichlorobenzene was investigated by shearing tests, electron microscope, and DSC measurements. All of the gels showed such a strong adhesive strength over 36 kg/cm2 that polyethylene plates of 3 mm in thickness gave rise to necking sufficient for practical use, when heated at 120 °C for 2 h. In particular, the gel in tetralin showed a strong adhesive strength when heated at 110 °C. It was found that adhesive strength increases with the heating temperature; the temperatures at which adhesive strength begins to increase differ depending on the type of polyethylene sample and solvent. It is apparent that polyethylene gels exhibit an adhesive effect when they are heated at higher temperatures than the gel melting temperatures, and that the closer the SP values of solvents used for the gelation are to the molded polyethylene, the stronger the adhesion of the polyethylene molding.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01416055
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Reduction of carbon dioxide with methane over Ni-catalyst (1989)
    Springer
    Reaction kinetics and catalysis letters 39 (1989), S. 69-74 
    Details
    ISSN: 1588-2837
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Abstract Реакцию CO2+CH4=2CO+2H2+60 ккал/моль вели на катализаторах переходных металлов (Ni, Fe и Co). Катализатор Ni/Al2O3 оказался наилучшим для данной реакции. Выведено выражение скорости реакции и кажущейся энергии активации для Ni-катализатора.
    Notes: Abstract The reaction CO2+CH4=2CO+2H2+60 kcal/mol was carried out over some transition metal catalysts (Ni, Fe and Co) and Ni/Al2O3 catalyst was then found to be the best for the reaction. The reaction rate expression and the apparent activation energy were also obtained over the Ni catalyst.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02061857
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    A Mössbauer study on remarkable changes in chemical states of iron in silica-supported Pd-Fe bimetallic catalysts by varying Fe contents (1986)
    Springer
    Journal of radioanalytical and nuclear chemistry 106 (1986), S. 167-173 
    Details
    ISSN: 1588-2780
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Fe-57 Mössbauer spectra of silica-supported Pd−Fe bimetallic catalysts show remarkable changes with varying Fe/Pd atomic ratios. From the spectra, the main Fe-component is estimated as highly dispersed Fe in the Fe/Pd range of 0.05–0.3 and α-Fe ensemble and Fe−Pd intermetallics in the Fe/Pd range above 0.3. It is suggested that the chemical state of iron is associated with the catalytic performance in effective CO−H2 conversion to methanol.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02166787
    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...