ZIB

Treffer pro Seite

Treffer 1 - 5 | 5 Treffer

Sortierung

Digitale Medien

Two-wavelength operation of a tunable KrF excimer laser — A promising technique for combustion diagnostics (1990)

Ketterle, W. ; Arnold, A. ; Schäfer, M.

Springer

Applied physics 51 (1990), S. 91-93

zur Merkliste hinzufügen auf der Merkliste

Details

ISSN: 1432-0649

Schlagwort(e): 42.55.Gp ; 42.60.Da

Quelle: Springer Online Journal Archives 1860-2000

Thema: Physik

Notizen: Abstract A KrF excimer laser was operated on two independently tunable lines. This was achieved by a double-resonator configuration with two gratings. Tuning range and gain competition were investigated. The narrow line width (〈1 cm−1) and the independent tunability make this laser ideal for simultaneous spectroscopic detection of two species and temperature measurements in combustion processes.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1007/BF00326005

Permalink

Bibliothek	Standort	Signatur	Band/Heft/Jahr	Verfügbarkeit

Andere fanden auch interessant ...

Artikel (Nationallizenzen)

Volltext

Digitale Medien

Hexosamines in the organic layer of two beech forest soils: effects of mesofauna exclusion (1993)

Scholle, G. ; Joergensen, R. G. ; Schaefer, M. ; [weitere]

Springer

Biology and fertility of soils 15 (1993), S. 301-307

zur Merkliste hinzufügen auf der Merkliste

Details

ISSN: 1432-0789

Schlagwort(e): Mesofauna ; Amino sugar ; Soil micro-flora ; Beech forest ; Moder ; Lime

Quelle: Springer Online Journal Archives 1860-2000

Thema: Biologie , Geologie und Paläontologie , Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft

Notizen: Summary In December 1988, litter bags (mesh size: 45 and 1000 μm) were exposed in the organic layer of unlimed and limed moder soil under beech forest in the Solling area of Germany. Bags were retrieved on three sampling dates (May, September, and November 1989) and amounts (g m-2) of glucosamine and galactosamine were determined. Horizon-specific differences generally explained by far the largest part of the treatment variance. In the substrate sampled in December 1988 from the unlimed area glucosamine increased by a factor of 11.8 from the L 1 layer to the H layer and galactosamine by a factor of 15.9. With the exception of the F2 layer, the hexosamine amounts found in the limed substrate sampled in December 1988 were higher in all horizons than in the corresponding horizons sampled from the unlimed area. Exclusion of mesofauna from the 45-μm litter bags generally reduced the level of amino sugars at both sites. The difference between the two mesh sizes was most pronounced in the lowermost horizons (F2 and H) and quite small in the upper horizons. The exclusion of mesofauna significantly increased the glucosamine: galactosamine ratio in the two L layers of the unlimed soil on all sampling dates. Seasonal fluctuations suggested that the actual amino sugar content of the organic layer was essentially the function of two components, the first reflecting long-term accumulation of microbial metabo-lites, and the second reflecting short term fluctuations in the microbial colonization of various C sources together with spatial and temporal differences in the ability of the microflora to produce and to decompose hexosamines. The results of this study show that the mesofauna in the beech forest soils investigated significantly affected both the amino sugar components measured, and thus stimulated the accumulation of one of the most important N pools in forest soils.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1007/BF00337217

Permalink

Bibliothek	Standort	Signatur	Band/Heft/Jahr	Verfügbarkeit

Andere fanden auch interessant ...

Artikel (Nationallizenzen)

Volltext

Digitale Medien

Audiovocal interactions during development? Vocalisation in deafened young horseshoe bats vs. audition in vocalisation-impaired bats (1990)

Rübsamen, R. ; Schäfer, M.

Springer

Journal of comparative physiology 167 (1990), S. 771-784

zur Merkliste hinzufügen auf der Merkliste

Details

ISSN: 1432-1351

Schlagwort(e): Ontogeny ; Audition ; Vocalisation ; Sensorimotor interaction ; Rhinolophus rouxi

Quelle: Springer Online Journal Archives 1860-2000

Thema: Biologie , Medizin

Notizen: Summary Horseshoe bats (Rhinolophus rouxi) were deafened in their 3rd–5th postnatal week. Subsequently their vocalisations were monitored to evaluate the impact of audition on the development of echolocation pulses. Hearing impairment affected the echolocation pulses as follows: the frequency of the constant frequency (CF) component was altered by between + 4 kHz and − 14 kHz, and the dominance of the second harmonic of the pulses was neutralised by a relative increase in intensity of the first and third harmonics. A second experiment focused on possible influences of acoustical self-stimulation with echolocation pulses on the establishment of auditory fovea representation in the inferior colliculus (IC). Frequency control of echolocation pulses was disrupted by larynx denervation. Thereafter, the bats produced multiharmonic echolocation signals (4–11 harmonics) varying in frequency. IC tonotopy, however, as monitored by stereotaxic electrophysiology, showed the same developmental dynamics as seen in control specimens (Fig. 10). Both experiments indicate that throughout postnatal development echolocation pulses are under auditory feedback control, whereas maturation of the auditory fovea and shifts in its frequency tuning represent an innate process. The significance of this postnatal development might be the adjustment of the vocal motor system of each bat to the frequency of its ‘personal’ auditory fovea.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1007/BF00189767

Permalink

Bibliothek	Standort	Signatur	Band/Heft/Jahr	Verfügbarkeit

Andere fanden auch interessant ...

Artikel (Nationallizenzen)

Volltext

Digitale Medien

Ontogenesis of auditory fovea representation in the inferior colliculus of the Sri Lankan rufous horseshoe bat, Rhinolophus rouxi (1990)

Rübsamen, R. ; Schäfer, M.

Springer

Journal of comparative physiology 167 (1990), S. 757-769

zur Merkliste hinzufügen auf der Merkliste

Details

ISSN: 1432-1351

Schlagwort(e): Ontogeny ; Auditory fovea ; Tonotopy ; Sexual dimorphism ; Rhinolophus rouxi

Quelle: Springer Online Journal Archives 1860-2000

Thema: Biologie , Medizin

Notizen: Summary This report describes the ontogenesis of tonotopy in the inferior colliculus (IC) of the rufous horseshoe bat (Rhinolophus rouxi). Horseshoe bats are deaf at birth, but consistent tonotopy with a low-to-high frequency gradient from dorsolateral to ventromedial develops from the 2nd up to the 5th week. The representation of the auditory fovea is established in ventro-mediocaudal parts of the IC during the 3rd postnatal week (Fig. 3). Then, a narrow frequency band 5 kHz in width, comprising 16% of the bat's auditory range, captures 50–60 vol% of the IC (Fig. 3c). However, foveal tuning is 10–12 kHz (1/3 octave) lower than in adults; foveal tuning in females (65–68 kHz) is 2–3 kHz higher than in males (62–65 kHz). Thereafter, foveal tuning increases by 1–1.5 kHz per day up to the 5th postnatal week, when the adult hearing range is established (Figs. 4, 5). The increase of sensitivity and of tuning sharpness of single units also follows a low-to-high frequency gradient (Fig. 6). Throughout this development the foveal tuning matches the second harmonic of the echolocation pulses vocalised by these young bats. The results confirm the hypothesis of developmental shifts in the frequency-place code for the foveal high frequency representation in the IC.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1007/BF00189766

Permalink

Bibliothek	Standort	Signatur	Band/Heft/Jahr	Verfügbarkeit

Andere fanden auch interessant ...

Artikel (Nationallizenzen)

Volltext

Digitale Medien

Ionische Kronenetherkomplexe von Zinn(II) und Zinn(IV): [Sn(15-Krone-5)] [SnCl6] und [SnCl3(18-Krone-6)]2[Sn2Cl10]; Synthesen, IR-Spektren und 119Sn-Mößbauer-Spektren (1992)

Schäfer, M. ; Dehnicke, K.

Weinheim : Wiley-Blackwell

Zeitschrift für anorganische Chemie 615 (1992), S. 127-130

zur Merkliste hinzufügen auf der Merkliste

Details

ISSN: 0044-2313

Schlagwort(e): Ionic Crown Ether Complexes of Tin(II) and Tin(IV) ; synthesis ; IR spectra ; 119Sn-Mössbauer spectra ; Chemistry ; Inorganic Chemistry

Quelle: Wiley InterScience Backfile Collection 1832-2000

Thema: Chemie und Pharmazie

Beschreibung / Inhaltsverzeichnis: Ionic Crown Ether Complexes of Tin(II) and Tin(IV): [Sn(15-Crown-5)][SnCl6] and [SnCl3(18-Crown-6)]2[Sn2Cl10]; Syntheses, IR Spectra, and 119Sn-Mössbauer Spectra[Sn(15-crown-5)][SnCl6] (1,) has been prepared by the reaction of SnCl2, SnCl4, and 15-crown-5 in the molar ratio of 1 : 1 : 1 in acetonitrile solution, forming a white insoluble crystal powder. [SnCl3(18-crown-6)]2[Sn2Cl10] (2,) as well as [SnCl3(18-crown-6)][BiCl4] · CH3CN (3,) are prepared by the reaction of SnCl4 with 18-crown-6 (molar ratio 2 : 1), and of SnCl4, 18-crown-6, and BiCl3 (molar ratio 1 : 1 : 1), respectively. According to IR-spectroscopy and 119Sn-Mössbauer-spectroscopy 1-3, have ionic structures; the cation of 1, being polymeric via a sandwich-like structure.

Notizen: [Sn(15-Krone-5)] [SnCl6] (1,) entsteht als schwerlösliches weißes Kristallpulver aus SnCl2, SnCl4 und 15-Krone-5 im Molverhältnis 1 : 1 : 1 in Acetonitrillösung, während [SnCl3(18-Krone-6)]2[Sn2Cl10] (2,) aus SnCl4 und 18-Krone-6 im Molverhältnis 2 : 1 und [SnCl3(18-Krone-6)] [BiCl4] · CH3CN (3,) aus SnCl4, 18-Krone-6 und BiCl3 im Molverhältnis 1 : 1 : 1 gebildet werden. Aus den IR- und den 119Sn-Mößbauer-Spektren wird auf ionische Strukturen geschlossen; das Kation von 1, besitzt eine polymere Struktur, in der das Sn2+ -Ion über (15-Krone-5)-Moleküle sandwichartig gestapelt ist.

Zusätzliches Material: 3 Ill.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1002/zaac.19926150926

Permalink

Bibliothek	Standort	Signatur	Band/Heft/Jahr	Verfügbarkeit

Andere fanden auch interessant ...

Artikel (Nationallizenzen)

Volltext

Treffer 1 - 5 | 5 Treffer