ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

feed icon rss

Ihre E-Mail wurde erfolgreich gesendet. Bitte prüfen Sie Ihren Maileingang.

Leider ist ein Fehler beim E-Mail-Versand aufgetreten. Bitte versuchen Sie es erneut.

Vorgang fortführen?

Exportieren
Filter
  • Wiley-Blackwell  (10)
  • American Institute of Physics (AIP)  (5)
  • 1985-1989  (15)
  • 1
    Digitale Medien
    Digitale Medien
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 61 (1987), S. 3937-3939 
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: A computer program that simulates the logic functions of magnetic bubble devices has been developed. The program uses a color graphics screen to display the locations of bubbles on a chip during operation. It complements the simulator previously developed for modeling bubble devices on the gate level [Smith et al., IEEE Trans. Magn. MAG-19, 1835 (1983); Smith and Kryder, ibid. MAG-21, 1779 (1985)]. This new tool simplifies the design and testing of bubble logic devices, and facilitates the development of complicated LSI bubble circuits. The program operation is demonstrated with the design of an in-stream faulty loop compensator using bubble logic.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 2
    Digitale Medien
    Digitale Medien
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 89 (1988), S. 2257-2270 
    ISSN: 1089-7690
    Quelle: AIP Digital Archive
    Thema: Physik , Chemie und Pharmazie
    Notizen: We have studied the structure of a monolayer of C21H43OH on water, in the region near close packing, by grazing incidence in-plane x-ray diffraction. For all temperatures studied the isotherms in the πa plane show a kink, signaling a phase transition. Along an isotherm, and for pressures above the kink, we observe that the transverse structure factor has one peak which has constant position, width, and intensity; below the kink the diffraction peak shifts to smaller scattering vector (larger separation) and the amplitude decays as the surface pressure decreases, but the width of the peak remains constant. We rationalize these observations in terms of the influence on the transverse structure factor of gauche configurations in the amphiphile tails, with the kink representing the point at which the last of the gauche configurations is squeezed out of the chain. Along an isobar which is at higher pressure than the kink pressures of all isotherms crossed, the transverse structure factor has a single peak above a transition temperature and two peaks below that temperature; for π=30 dyn/cm the transition temperature is in the range 16.3〈T〈21.3 °C. We interpret this observation, by comparison with the properties of the lamellar crystalline n-paraffins, as a hexagonal-to-pseudohexagonal structural transition analogous to the crystal rotator II-to-rotator I transition. Our results imply that the hydrocarbon tails of the amphiphile molecules dominate the properties of the monolayer.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 3
    Digitale Medien
    Digitale Medien
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 90 (1989), S. 2393-2397 
    ISSN: 1089-7690
    Quelle: AIP Digital Archive
    Thema: Physik , Chemie und Pharmazie
    Notizen: Frequently, time-dependent effects are seen in monolayers of amphiphilic molecules (Langmuir films) when they are compressed, so that the pressure after some time is different from that recorded immediately after compression. We have identified for the first time a microscopic relaxation mechanism in monolayers of heneicosanol (C21H43OH): namely, a transition from a uniaxially distorted ("pseudohexagonal'') structural, formed upon compression, to an undistorted hexagonal structure. For T〉20 °C we observe only an apparently hexagonal phase, while at T=5 °C we observe only an apparently stable pseudohexagonal phase. When 10≤T≤20 °C, the monolayer structure changes with time from pseudohexagonal to hexagonal. The rate at which this transformation occurs is strongly temperature dependent. We propose that the observed temperature dependence is determined by the rate of nucleation of a hexagonal phase from a metastable shear-induced structure.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 4
    Digitale Medien
    Digitale Medien
    [S.l.] : American Institute of Physics (AIP)
    Physics of Fluids 30 (1987), S. 1564-1566 
    ISSN: 1089-7666
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: By adjusting the electrostatic potential on the end plates of a mirror plasma, the plasma's magnetohydrodynamic (MHD) stability can be altered. Furthermore, the plasma's MHD response to low-frequency modulation of the end plates can be used to pump unwanted ions that collect in a thermal barrier. Here, precise boundary conditions are derived for the MHD equations of motion to model an end plate separated from the plasma by a sheath.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 5
    Digitale Medien
    Digitale Medien
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 51 (1987), S. 1089-1090 
    ISSN: 1077-3118
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: The lifetime of the lowest quasibound state localized between the barriers of a GaAs/AlGaAs double-barrier structure is calculated as a function of barrier and well dimensions. The results are consistent with high-frequency experiments.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 6
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 9 (1986), S. 281-284 
    ISSN: 0935-6304
    Schlagwort(e): Liquid chromatography, HPLC ; Time-switched detectors ; UV detection ; Fluorimetric detection ; Vitamin A ; Vitamin E ; Chemistry ; Analytical Chemistry and Spectroscopy
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: An HPLC method utilizing a UV and a fluorimetric detector linked in series is described. By use of a simple integrator-controlled time-switched relay, analysis of serum vitamin A and E is accomplished on the same chromatogram and at optimum sensitivity for each detector. A single internal standard (retinyl acetate) monitored only by the UV detector permits measurement of both vitamins over a wide linear range. Precision of the assays is satisfactory, both on a within-day and on a day-to-day basis. Recoveries of both vitamins are virtually 100% whilst sensitivity is 2 μg/L (retinol) and 0.05 mg/L (α-tocopherol).
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 7
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 525 (1985), S. 7-13 
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: NMR Spectroscopic Studies of 15N Labelled N-Methyl-imidodiphosphoric Acid Derivatives15N labelled compounds (EtO)mCl2-m(O)P—NMe—P(O)(OEt)nCl2-n (m = 0-2, n = 0-2) were prepared as a mixture and investigated by means of 31P and 15N NMR spectroscopy. The chemical shift values δP and δN, and the coupling constants 1JPN and 2JPP are discussed and interpreted qualitatively by semiempirical quantumchemical calculations (CNDO/2) using POPLE'S ΔE-model.
    Notizen: 15N-markierte Verbindungen der Substitutionsreihe (EtO)mCl2-m(O)P—NMe—P(O)(OEt)nCl2-n (m = 0-2, n = 0-2) wurden im Reaktionsgemisch synthetisiert und mit Hilfe der 31P- und 15N-NMR-Spektroskopie untersucht. Die chemischen Verschiebungen δP und δN sowie die Kopplungskonstanten 1JPN und 2JPP werden diskutiert und qualitativ mit Hilfe halbempirischer quantenchemischer Rechnungen (CNDO/2) im Rahmen des POPLE-schen ΔE-Modells interpretiert.
    Zusätzliches Material: 2 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 8
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 523 (1985), S. 112-120 
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: NMR Spectroscopic Studies on the Thiolysis Reaction of Decachlorocyclopentaphosphazenen, N5P5Cl10A series of different but exclusively geminally substituted products, N5P5Cl10-n(SR)n, is formed by reactions of decachlorocyclopentaphosphazene, N5P5Cl10, with sodium ethanethiolate, NaSEt, or benzenethiolate, NaSPh, in benzene or ether. The degree of substitution is low (mainly up to n = 4); intensified conditions do not result in further substitution but in decomposition. The compounds were separated by column chromatography and identified by 31P NMR spectroscopy. 31P chemical shifts and P - P coupling constants of the investigated compounds systematically change with the progressive substitution by SR groups. The chlorine-replacement pattern is discussed.
    Notizen: Bei Umsetzungen von Decachlorocyclopentaphosphazen, N5P5Cl10, mit Natriumethanthiolat, NaSEt, order -benzenthiolat, NaSPh, in Benzen bzw. Ether entsteht eine Reihe unterschiedlicher, aber ausschließlich geminaler Substitutionsprodukte, N5P5Cl10-N(SR)n, niederen Substitutionsgrades (im wesentlichen bis zu n = 4); verschärfte Reaktionsbedingungen führen nicht zu weiterer Substitution, sondern zur Zersetzung. Die Verbindungen wurden säulenchromatographisch getrennt und mit Hilfe der 31P-NMR-Spektroskopie identifiziert. 31P-chemische Verschiebungen und P - P-Kopplungskonstanten der untersuchten Verbindungen ändern sich systematisch mit fortschreitender Substitution durch SR-Gruppen. Der Substitutionsverlauf wird diskutiert.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 9
    ISSN: 0018-019X
    Schlagwort(e): Chemistry ; Organic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The synthesis of tri-N-acetylated heparin pentasaccharide 2 is described. It was assembled from five suitably blocked monosaccharide units (3-7). Glucuronic-acid building block 4 was prepared from glucose by direct Jones oxidation of the 6-O-trityl derivative 18. The resulting acid 16 was esterified to 17 in large mounts using methyl chloroformate/base. Trimethylsilyl bromide proved to be an excellent reagent for the hydrolysis of a prop-1-enyl glycoside (19 →21). The pentasaccharide 29 was obtained by a [2 + 2] + 1 synthesis, the glycosylation reactions furnished good to very good yields. The identity of protected oligosaccharides was confirmed by 1H-NMR spectroscopy. Sequential deblocking of the pentasaccharide, O-sulfation, and N-acetylation gave 2 which was shown to exhibit ca. 600 times lower anticoagulant activity than pentasaccharide 1.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 10
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Zeitschrift für die chemische Industrie 97 (1985), S. 745-760 
    ISSN: 0044-8249
    Schlagwort(e): Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Es ist schon sehr lange bekannt, daß sich manche Übergangsmetallsulfide in wäßrigem Ammoniumpolysulfid lösen. Obwohl anzunehmen war, daß sich dabei Metallpolysulfide bilden, hat man sich diesem Verbindungstyp erst in den letzten Jahren intensiver zugewandt. Dabei konnte eine Fülle neuer Komplexe mit Polysulfido-Chelatliganden Sn2- (n=2,3,4…) isoliert und charakterisiert werden. Die Komplexe interessieren bezüglich ihrer Struktur und Reaktivität, aber auch im Hinblick auf mögliche Anwendungen; mit ihnen können Schwefelringe definierter Größe gezielt hergestellt werden, und es deutet sich an, daß sie auch in der Katalyse Verwendung finden könnten.
    Zusätzliches Material: 26 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
Schließen ⊗
Diese Webseite nutzt Cookies und das Analyse-Tool Matomo. Weitere Informationen finden Sie hier...