Bibliothek

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
  • Artikel: DFG Deutsche Nationallizenzen  (32)
  • 1995-1999  (23)
  • 1980-1984  (9)
Datenquelle
  • Artikel: DFG Deutsche Nationallizenzen  (32)
Materialart
Erscheinungszeitraum
Jahr
  • 1
    Digitale Medien
    Digitale Medien
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 77 (1995), S. 3308-3314 
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: Atomic force microscopy used in the resonant mode is a powerful tool for measuring local surface properties: for example, the quantitative analysis of the electrical forces induced by the application of an electric field between a conductive microscope tip and a surface allows the determination of the tip/surface capacitance and the local surface work function. However, these quantitative analyses require knowledge of tip geometry. In this article, we show that the simple procedure of evaluating the tip curvature radius by fitting the variations of the electrostatic force with the tip-surface distance is not always adapted to the case where one of the tip-surface system elements is a semiconductor. However, particular experimental conditions are determined to overcome these difficulties. © 1995 American Institute of Physics.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 2
    Digitale Medien
    Digitale Medien
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 107 (1997), S. 8866-8873 
    ISSN: 1089-7690
    Quelle: AIP Digital Archive
    Thema: Physik , Chemie und Pharmazie
    Notizen: The (2Πg3/2,1/2)nf Rydberg states of CS2 are investigated by means of (3+1) resonance enhanced multiphoton ionization (REMPI) time-of-flight (TOF) spectroscopy. The excitation spectrum of jet-cooled carbon disulfide has been obtained in the 74 000–81 000 cm−1 energy region. From the CS2+ mass selected REMPI spectra, the nf Rydberg series have been clearly identified and they have been found converging to the two spin–orbit components of the CS2+ (X 2Πg) ground state corresponding to the n=4–11 members. Comparison of the CS2+, CS+, S+ mass selected REMPI spectra gave a better insight of the competition between dissociation and ionization processes. The use of linearly and circularly polarized laser light, selection rules and quantum defect considerations have led to a preliminary analysis of the measured nf complexes. © 1997 American Institute of Physics.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 3
    Digitale Medien
    Digitale Medien
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 105 (1996), S. 6147-6153 
    ISSN: 1089-7690
    Quelle: AIP Digital Archive
    Thema: Physik , Chemie und Pharmazie
    Notizen: The polarization dependence of the (2+1) and (3+1) resonance enhanced multiphoton ionization of OCS have been investigated in the 70 500–74 500 cm−1 energy region. This region contains a complex system of bands arising from the excitation of the 4p Rydberg states. The symmetry of most of the observed bands have been unambiguously determined based on the intensity changes of the two and three photon resonant spectra using both linearly and circularly polarized light. These results generally confirm the assignments suggested in a previous study. New bands have also been observed and some new assignments are proposed. The vibrational frequencies ν1, ν2, and ν3 of the Rydberg states in that energy region are determined. © 1996 American Institute of Physics.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 4
    Digitale Medien
    Digitale Medien
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 66 (1995), S. 2848-2852 
    ISSN: 1089-7623
    Quelle: AIP Digital Archive
    Thema: Physik , Elektrotechnik, Elektronik, Nachrichtentechnik
    Notizen: In resonant atomic force microscopy (AFMR) the calibration of the tip–sample relative displacement remains a major problem. Commonly used PZT piezoceramics exhibit a nonlinear behavior response for large applied voltages. For low voltages applied to the piezoceramics (i.e., small corrugations), the calibration can be performed by measuring the height of known structures. For large displacements, the interferometric heterodyne detection used in the AFMR provides a relative tip–sample displacement up to 10 μm, without removing the piezo-tube from the microscope. From these measurements, it was established that the piezosensitivity is not a constant parameter. Its averaged value during an excursion depends linearly on the applied voltage. With this system, routine controls are very easy and an example is given of the displacement corrections related to the nonlinearity of the piezo-tube for the electrostatic interaction between the tip and a gold surface. © 1995 American Institute of Physics.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 5
    Digitale Medien
    Digitale Medien
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 86 (1999), S. 5245-5248 
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: In this article we show that in the atomic force microscopy experiments performed on a metallic surface, there is always a long range electrostatic force in addition to the van der Waals forces. This capacitive force is due to the contact potential between the tip and the surface and exists even without external applied potential. We have calculated this capacitive force for a real geometry of the tip–sample system and compared it to the van der Waals force calculated for the same geometry. We conclude that the electrostatic force is always dominant for a tip–surface distance larger than half of the tip radius of curvature. © 1999 American Institute of Physics.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 6
    ISSN: 1077-3118
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: A GaAs/AlAs microcavity containing six InGaAs quantum wells was grown, and the sample was then etched via chemically-assisted ion-beam etching to form 50-μm-diam cylindrical mesas. The formation of native oxides, accomplished by baking the samples at 400 °C in the presence of a pressurized N2/H2O vapor line, lowered the refractive index of the AlAs layers to 1.5. The higher refractive index contrast more effectively confined the intracavity field, leading to well-resolved reflectivity dips with an exciton-polariton splitting of 6.72 nm=9.44 meV at room temperature. © 1996 American Institute of Physics.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 7
    ISSN: 1398-9995
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: Recent studies have found a higher prevalence of allergic rhinitis and atopic sensitization among adults living in eastern than those living in western Germany. We hypothesize that prevalence rates were similar before Germany was divided and diverged after the division. Because there are no historical data comparing atopic status between the two parts of Germany, we tested this hypothesis by comparing the prevalence of atopy among persons who were born during different decades. As part of the EC Respiratory Health Survey, a respiratory health questionnaire was mailed to a population-based sample of 8363 subjects aged 20–44 years from a city in the former West Germany (Hamburg) and a city in the former East Germany (Erfurt). Of the target population. 6428 (77%) subjects responded. Subsamples of 731 subjects from Erfurt and 1159 subjects from Hamburg participated in medical examinations, including skin prick tests and specific IgE measurements. Prevalence rates of allergic sensitization were similar in Hamburg and Erfurt for those born in the periods 1946–51 and 1952–61. respectively, but differed between Hamburg and Erfurt subjects born in the period 1962–71. After adjustment for several potential predictors, the younger subjects from Hamburg had a higher odds ratio (OR) of sensitization than those Hamburg subjects born before 1952 (skin prick test reactivity: OR 2.06. any specific IgE 〉 0.35 kU/1: OR 1.61). The younger subjects from Erfurt were not more frequently sensitized than the older subjects (skin prick test reactivity: OR 1.05. any specific IgE 〉 0.35 kU/1: OR 0.79). No single allergen could be identified as responsible for the observed difference. We conclude that factors related to a “Western lifestyle”, which were prevalent in the West German city during the 1960s and i970s. may be responsible for the higher prevalence of allergic sensitization observed in Hamburg.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 8
    Digitale Medien
    Digitale Medien
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Sociology 6 (1980), S. 479-508 
    ISSN: 0360-0572
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Sociologie
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 9
    Digitale Medien
    Digitale Medien
    Springer
    Skeletal radiology 7 (1981), S. 75-77 
    ISSN: 1432-2161
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 10
    Digitale Medien
    Digitale Medien
    Springer
    Der Ophthalmologe 95 (1998), S. 44-50 
    ISSN: 1433-0423
    Schlagwort(e): Key words Vision in road traffic • Vision and risk of accident • Mesopic vision • Sensitivity to glare ; Schlüsselwörter Sehen im Straßenverkehr • Sehvermögen und Unfallrisiko • Dämmerungssehvermögen • Blendempfindlichkeit
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Fragestellung: Klärung der Frage nach dem Zusammenhang zwischen Unfallhäufigkeit im Straßenverkehr und Störungen des Sehvermögens. Material und Methode: Es wurden 754 Unfallfahrer einer vollständigen augenärztlichen Untersuchung unterzogen. 250 Personen mit vergleichbarer Alterszusammensetzung und Fahrerfahrung wurden als Kontrollgruppe rekrutiert. Die Altersverteilung der Unfallfahrer liegt im Durchschnitt bei 56,3 Jahren, bei den Kontrollen bei 57,7 Jahren (Unterschied statistisch nicht signifikant). Ergebnisse: Bei allen 3 analysierten Unfalltypen (Dunkelheitsunfall, Vorfahrtsverletzung und Überholunfall im Außerortsverkehr) zeigte sich eine statistisch signifikante Häufung von reduzierter Tagessehschärfe, gestörtem Dämmerungsseh- vermögen und erhöhter Blendempfindlichkeit. Eine Vielzahl der übrigen Sehfunktionen war ebenfalls pathologisch, wobei sich gewisse Unterschiede je nach Unfalltyp zeigten. Besonders auffällige Unterschiede gab es zwischen Kontrollkollektiv und Unfallfahrern beim Dämmerungssehvermögen und der Blendempfindlichkeit, speziell bei Dunkelheitsunfällen. Bei den 261 Unfallfahrern der Gruppe „Dunkelheitsunfall“ haben ohne Blendung 15,0 % den Grenzkontrast von 1 : 5 nicht mehr erreicht, mit Blendung 20,7 %. Im Kontrollkollektiv liegt der Anteil derjenigen, die den kritischen Kontrast von 1 : 5 nicht mehr erreicht haben, ohne Blendung bei lediglich 4 %, mit Blendung bei 7,6 %. Diese Unterschiede sind hoch signifikant. Dem steht gegenüber, daß viele der Unfallfahrer ihr Sehvermögen subjektiv als „sehr gut“ eingeschätzt haben. Schlußfolgerung: Die Ergebnisse der Studie zeigen, daß Einschränkungen von Dämmerungssehvermögen und Blendempfindlichkeit mit einem erhöhten Risiko für Nachtunfälle (Auffahren auf unbeleuchtete Hindernisse etc.) einhergehen. Dies unterstreicht die Forderung nach regelmäßigen Prüfungen von Dämmerungssehvermögen und Blendempfindlichkeit im Rahmen der Fahreignungsbegutachtung, was derzeit gemäß den Vorschriften der Straßenverkehrszulassungsordnung in Deutschland leider nicht der Fall ist.
    Notizen: Background: This study was carried out to investigate the relationship between the frequency of traffic accidents and impaired vision. Materials and methods: Seven hundred and fifty-four drivers involved in accidents were recruited, in addition to 250 accident-free drivers similar in age and driving experience as an control group. The age distribution of the persons involved in traffic accidents (mean 56.3 years) was similar to that of the control group (mean 57.7 years), the difference was not statistically significant. Both groups underwent a complete ophthalmological examination. Results: All three types of accidents (night-time accidents, violations of right of way, accidents during an overtaking manoeuvre) had a statistically significantly higher incidence of reduced photopic visual acuity, mesopic vision and an increased sensitivity to glare. Some other visual functions were also abnormal, with differences according to the type of accident. In particular, there were noticeable differences between the control group and those who were involved in night-time accidents regarding mesopic vision and sensitivity to glare. Concerning mesopic vision, 15 % of the 261 persons involved in night-time accidents did not reach the contrast limit of 1 : 5; with glare, 20.7 % failed. In comparison 4 % of the control group reached this critical limit without glare and 7.6 % with glare. These differences are highly statistically significant. In contrast to these findings, many of the drivers involved in accidents assessed their own visual capability as “excellent”. Conclusions: The results of this study show that reduced mesopic vision and increased sensitivity to glare are accompanied by an increased risk of night-time accidents (for example, collisions with a non-illuminated obstacle). This emphasizes the importance of regular ophthalmological check-ups including visual functions such as mesopic vision and sensitivity to glare, which currently are not required by the traffic laws in Germany.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
Schließen ⊗
Diese Webseite nutzt Cookies und das Analyse-Tool Matomo. Weitere Informationen finden Sie hier...