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Lilli Heinrich und Werner Baltes 《Zeitschrift für Lebensmitteluntersuchung und -Forschung A》1987,185(5):362-365
Zusammenfassung In zwei unterschiedlich gerösteten Robustakaffees und vier handelsüblichen Röstkaffees wurden die Phenole in bezug auf Struktur und Quantität untersucht. Nach speziellen Extraktions- und Reinigungsverfahren erfolgte die Identifizierung und Quantifizierung nach gaschromatographischer Trennung der Trimethylsilylether mit Hilfe der GC-MS-Kopplung. Die Gehalte der 35 identifizierten Phenole lagen in einem Bereich von unter 0,1 bis über 1000 mg/kg. 16 Phenole wurden erstmals im Kaffee nachgewiesen.
Herrn Dr. H. Lange zum 60. Geburtstag gewidmet 相似文献
Determination of phenols in coffee
Summary The structure and quantity of phenols, occurring in two different roastedRobusta coffees and in four samples of roast coffee, were investigated. Identification and quantification were carried out after special extraction procedures and clean-up methods by gas chromatography/mass spectrometry. The quantities of 35 phenols investigated ranged from below 0.1 mg/kg to more than 1000 mg/kg. Sixteen phenols were identified in coffee for the first time.
Herrn Dr. H. Lange zum 60. Geburtstag gewidmet 相似文献
14.
Fracture toughness and fatigue crack propagation (FCP) of plain and modified anhydride-cured epoxy resin (EP) were studied at ambient temperature. Liquid carboxyl-terminated acrylonitrile-butadiene (CTBN) and silicon (SI) rubber dispersions were used as tougheners for the EP. The morphology of the modified EP was characterized by dynamic mechanical analysis (DMA) and by scanning electron microscopy (SEM). The fracture toughness, Kc, of the compositions decreased with increasing deformation rate. Kc of the EP was slightly improved by CTBN addition and practically unaffected by incorporation of the SI dispersion when tests were performed at low cross-head speed, v. Both modifiers improved Kc at high v, and also the resistance to FCP, by shifting the curves to higher stress intensity factor ranges, ΔK, by comparison with the plain EP. It was established that both fracture and fatigue performance rely on the compliance, JR, at the rubbery plateau, and thus on the apparent molecular mass between crosslinks, Mc. The failure mechanisms were less dependent upon the loading mode (fracture, fatigue), but differed basically for the various modifiers. Rubber-induced cavitation and shear yielding of the EP were dominant for CTBN, whereas crack bifurcation and branching controlled the cracking in SI-modified EP. The simultaneous use of both modifiers resulted in a synergistic effect for both the fracture toughness at high deformation rate and the FCP behavior. 相似文献
15.
Injectorless quantum-cascade (QC) lasers, for the first time comparable to conventional QC lasers, are presented. The samples are based on InP and the active region is designed as a four-level staircase, realised in the strain-compensated material system Ga/sub 0.4/In/sub 0.6/As/Al/sub 0.56/In/sub 0.44/As. Low threshold current densities and a maximum operating temperature of 350 K have been achieved, due to an optimised design. At 77 K the wavelength is about 10 /spl mu/m, while threshold current densities of 0.9 kA/cm/sup 2/ have been observed, which compare well with those of conventional QC lasers in this wavelength region. 相似文献
16.
Nicotin und Ioan D. Vldescu 《Zeitschrift für Lebensmitteluntersuchung und -Forschung A》1938,75(5):450-457
Ohne Zusammenfassung 相似文献
17.
Pigeons pecked for food in a spatially cued choice reaction time (RT) task. A brief (50-msec) white light appeared on a left or right key and probabilistically predicted the location (on either the left or right key) of a subsequent target stimulus. The time between cue and target onset (stimulus onset asynchrony), the base rate of left cues, and the probability that the cue correctly predicted the target (cue validity) were experimentally varied. The mean RT to respond to the target key was faster on correctly cued trials (defining a validity effect), decreased for both valid and invalid trials as stimulus onset asynchrony increased (defining an alerting effect), showed a variety of base-rate effects, and did not depend on cue validity. It is shown with a computational-processing model that dynamic interactions of short-term and associative memory processes are sufficient to produce these attention-like empirical phenomena. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
18.
Ohne Zusammenfassung 相似文献
19.
RE Friedrich A Krüll R Schwarz H Thurmann K Plambeck R Schmelzle 《Canadian Metallurgical Quarterly》1997,173(10):507-512
PURPOSE: The clinical effect of high-dose-rate (HDR) interstitial brachytherapy combined with tumor resection was investigated in this retrospective study on patients with recurrent oral and oropharyngeal squamous cell carcinoma. PATIENTS AND METHODS: Oral and oropharyngeal squamous cell carcinoma in 38 patients were treated over a period of 7 years (1988-1994) by HDR interstitial brachytherapy using Gammamed 12i equipment. Pretreatment of patients in terms of irradiation and surgery differed (33 irradiated with a total dose between 60.0 and 75.6 Gy, including 8 patients with additional surgery; 1 patient with surgery alone, and 4 patients without any pretreatment). Indications for interstitial brachytherapy differed according to individual responses to treatment and medical histories. RESULTS: Interstitial brachytherapy was successful in the majority of patients, i.e. complete remission: 12, partial remission: 19, no change: 2, progression: 5. Local control and overall survival including patients with surgical treatment was 59% and 81% at 6 months and 47% and 49% after 12 months, respectively. CONCLUSION: Interstitial HDR brachytherapy with Iridium 192 is recommended in patients with local recurrences or second primary carcinomas after previous external radiotherapy in the head and neck region. Combination of interstitial brachytherapy and surgery is preferable for these patients. 相似文献
20.
M. Friedrich 《Molecular nutrition & food research》1985,29(4):346-346