Library

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
    Springer
    Fresenius' journal of analytical chemistry 361 (1998), S. 513-514 
    ISSN: 1432-1130
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Fresenius' journal of analytical chemistry 361 (1998), S. 568-569 
    ISSN: 1432-1130
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The microstructure and the composition of CVD silicon carbide films used as fiber coatings in composite materials were investigated by photoelectron spectroscopy and transmission electron microscopy. The films with a uniform thickness of 50 nm consisted of small SiC grains with a mean diameter of 15 nm and showed a stripe contrast in bright field images. Large grains with diameters in the dimension of the film thickness were used for imaging the lattice structure by high-resolution electron microscopy. The results are discussed as a polytype of cubic lamellae of a few nanometers and intermediate random stacking sequences of hexagonal structure.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Fresenius' journal of analytical chemistry 361 (1998), S. 653-655 
    ISSN: 1432-1130
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Investigations on CVD boron nitride films on fibres by means of photoelectron and X-ray spectroscopy resulted in B/N ratios above the stoichiometric value 1 and oxygen contents up to 25 at%. Compared to the hydrolytic rate of the films an apparent dependence was found on the deposition rate and some evidence of the oxygen concentration. CVD fibre coatings exhibit a hexagonal turbostratic structure with extremely small atomic layer plane dimensions, which was proved by transmission electron microscopy. Corresponding to oxygen concentrations in pyrolytic carbon films with similar structure a model is proposed, where the small atomic layers with dimensions of some nanometers cause a relatively high oxygen concentration in the boron nitride films. The oxygen atoms saturate the dangling bonds. Moreover the B/N ratio extents the expected stoichiometric ratio due to the oxygen atoms at nitrogen sites.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    ISSN: 1432-1238
    Keywords: Key words Transportation of patients ; Critical illness ; Mechanical ventilation ; Critical care ; Predictors
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Objectives: Critically ill patients are often transferred due to the growing number of diagnostic procedures required to be performed outside the intensive care unit. These transfers have proved to be very critical. The aim of this study was to evaluate predictors for the deterioration of respiratory function in critically ill patients after transfer. Design: Prospective, clinical, observational study. Setting: 1800-bed university teaching hospital. Subjects: 98 mechanically ventilated patients were investigated during transfer. Measurement and main results: Before transfer, all patients were classified according to the Acute Physiology and Chronic Health Evaluation (APACHE) II score and the Therapeutic Intervention Scoring System (TISS). Haemodynamics and arterial blood gases were measured at 11 different times. Arterial oxgen tension (PaO2), fractional inspired oxygen (FIO2), PaO2/FIO2 ratio, lowest PaO2/FIO2 ratio, minimal PaO2 and maximal FIO2, APACHE II score, TISS before transfer, age and duration of transfer were analysed as potential predictors for deterioration of respiratory function after transfer. Variables were analysed using Classification and Regression Trees and Clustering by Response. In 54 transports (55 %) there was a decrease in the PaO2/FIO2 ratio, and a decrease of more than 20 % from baseline was noted in 23 of the transferred patients (24 %). Age 〉 43 years and FIO2 〉 0.5 were identified as predictors for respiratory deterioration. Conclusions: Our predictors were able to indicate deterioration after transfer correctly in 20 of 22 patients (91 %), combined with a false-positive rate in 17 of 49 (35 %).
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    Springer
    The European physical journal 2 (1998), S. 29-32 
    ISSN: 1434-6079
    Keywords: PACS. 32.80.Pj Optical cooling of atoms; trapping - 32.60.+i Zeeman and Stark effects - 34.50.-s Scattering of atoms, molecules, and ions
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract: Collisions of ions, stored in a Penning trap, with neutral background molecules usually lead to rapid ion loss from the trap unless the ions are excited by the sum of the frequencies of the reduced cyclotron and magnetron motion. Then the ions are cooled by collisions and are driven to the trap centre leading to substantial increase of the storage time. Furthermore in a three level system including a long living metastable state collisions deexcite this metastable state and increase the population density in the ionic ground state. In a laser spectroscopic experiment we demonstrate the advantages of collisions on Ba+ ions stored in a Penning trap. The combined action of metastable state quenching, axialisation and cooling leads to a significantly enhanced laser induced fluorescence signal. The cross section for collisional relaxation of the ground state Zeeman levels has been determined and we find that it is of the same order of magnitude as quenching cross section for a metastable state. Cooling and increased signal strength allows us to observe extremely narrow resonances and motional sidebands in microwave induced Zeeman transitions in the Ba+ electronic ground level.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    Springer
    The European physical journal 4 (1998), S. 279-284 
    ISSN: 1434-6079
    Keywords: PACS. 21.10.Ky Electromagnetic moments - 32.60.+i Zeeman and Stark effects
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract: Laser-microwave double and triple resonance experiments were performed on clouds of Ba+ ions confined in a Penning ion trap to induce and detect electronic and nuclear spin flip transitions. Collisions with buffer gas molecules in the trap was used to reduce the lifetime of a long lived metastable state of the ions, in which population trapping might occur, and to cool the ions to the ambient temperature. Loss of ions from the trap by collisions were prevented by coupling the magnetron and reduced cyclotron motions by an additional r.f. field at the sum frequency of the two motions. Electronic Zeeman transitions in 138Ba+ and 135Ba+ were observed at a full width of about 3 kHz at a transition frequency of 80 GHz. The uncertainty of the line center was . From the magnetic field calibration by the cyclotron resonance of electrons stored in the same trap the gJ-factor for both isotopes could be determined to . From radiofrequency induced transitions of 135Ba+ the nuclear g-factor could be determined . Both measurements improve earlier results by about one order of magnitude.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    ISSN: 1572-9540
    Keywords: ion-trap ; hyperfine structure ; 7Be ; laser cooling
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract In order to investigate the nuclear magnetic moments and the magnetization distributions in the unstable nuclei of 7,11Be, laser-microwave spectroscopy experiments using an ion-trap are under progress at IPNS, KEK-Tanashi. Status of the experiment for the first unstable isotope 7Be is reported.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...