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We report new measurements of the effective thermal conductivity Keff and relaxation time τ in dilute mixtures of3He in superfluid4He, with molar concentrationsX≤10−3. The temperature range extended fromT≈1.4 K toT
λ. Both Kcff and τ are found to agree with theoretical predictions, in contrast to previous experiments where significant differences
were observed. A new thermal conductivity cell design was used which almost completely eliminates extraneous volumes and surfaces,
and the earlier results are explained in relation to these design changes. 相似文献
3.
Various image processing applications exploit a model of the human visual system (HVS). One element of HVS-models describes the masking-effect, which is typically parameterized by psycho-visual experiments that employ superimposed sinusoidal stimuli. Those stimuli are oversimplified with respect to real images and can capture only very elementary masking-effects. To overcome these limitations a new psycho-visual test method is proposed. It is based on natural scenery stimuli and operates in the wavelet domain. The collected psycho-visual data is finally used to evaluate the performance of various masking models under conditions as found in real image processing applications like compression. 相似文献
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W Dobrowsky J Naudé J Widder E Dobrowsky W Millesi R Pavelka C Grasl M Reichel 《Canadian Metallurgical Quarterly》1998,42(4):803-806
PURPOSE: To evaluate the effect of mitomycin C to an accelerated hyperfractionated radiation therapy. The aim was to test a very short schedule with/without mitomycin C (MMC) with conventional fractionation in histologically verified squamous cell carcinoma of the head and neck region. METHODS AND MATERIALS: From October 1990 to December 1996, 188 patients entered the trial. Tumors originated in the oral cavity in 54, oropharynx in 82, larynx in 20, and hypopharynx in 32 cases, respectively. Patients' stages were predominantly T3 and T4 (158/188, 84%) and most patients had lymph node metastases (144/188, 77%) at diagnosis. Only 22 patients were female, 166 were male, the median age of patients was 57 years (range 34 to 76 years). Patients were randomized to one of the following three treatment options: conventional fractionation (CF) consisting of 70 Gy in 35 fractions over 7 weeks (65 patients) or continuous hyperfractionated accelerated radiation therapy (V-CHART; 62 patients) or continuous hyperfractionated accelerated radiation therapy with 20 mg/sqm MMC on day 5 (V-CHART + MMC; 61 patients). By the accelerated regimens, the total dose of 55.3 Gy was delivered within 17 consecutive days, by 33 fractions. On day 1, a single dose of 2.5 Gy was given, from day 2 to 17 a dose of 1.65 Gy was delivered twice: the interfraction interval was 6 hours or more. RESULTS: Mucositis was very intense after accelerated therapy, most patients experiencing a grade III/IV reaction. The mucosal reaction did not differ whether MMC was administered or not. Patients treated by accelerated fractionation experienced a confluent mucosal reaction 12-14 days following start of therapy and recovered (no reaction) within 6 weeks. The skin reaction was not considered different in the three treatment groups. Those patients treated with additional chemotherapy experienced a grade III/IV hematologic toxicity in 12/61 patients. Initial complete response (CR) was recorded in 43% following CF, 58% after V-CHART, and 67% after V-CHART + MMC, respectively (p < 0.05). Actuarial survival (Kaplan-Meier) was significantly improved in the combined treated patients. Local tumor control was 28%, 32%, and 56% following CF, V-CHART, and V-CHART + MMC, respectively (p < 0.05). CONCLUSION: We conclude that our continuous hyperfractionated accelerated radiation therapy regimen is equal to conventional fractionation, suggesting that by shortening the overall treatment time from 7 weeks to 17 days a reduction in dose from 70 Gy to 55.3 Gy is possible, with maintenance of local tumor control rates. The administration of MMC to the accelerated regimen is tolerable and improves the outcome for patients significantly. 相似文献
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Helmut Richter Dr. rer. nat. Horst W. Tamler Dr. rer. nat. 《JOM Journal of the Minerals, Metals and Materials Society》1994,46(10):46-47
A new on-line texture-analyzing system and its application to nondestructive r value determination is discussed. In addition to providing a brief theoretical background and describing the instrumental set-up, the article presents off-line measurements with this equipment and demonstrates the high accuracy of the determined r-values. A special feature of the unit is the possibility to simultaneously measure the most important r values—r0, r45, r90, and rm. 相似文献
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Hartmut Rehbein Horst Karl 《Zeitschrift für Lebensmitteluntersuchung und -Forschung A》1985,180(5):373-378
Summary The extraction of fish muscle protein using SDS containing solubilization buffers was studied varying the time and the temperature of solubilization, as well as pH and SDS concentration of the buffer. At pH < 6 the myofbrillar proteins were incompletely solubilized; temperatures of 80-100 °C resulted in protein degradation observable in the SDS-PAGE.Samples of fish muscle containing high amounts of formaldehyde (50 mmoles FA/kg wet weight) could only be solubilised at 100 °C; on the other hand it was possible to solubilize cooked and/or canned products under mild conditions (2% SDS, 1% 2-ME, pH 8.9, shaking for 2 h at 60 °C).
Abbreviations FA formaldehyde - IEF isoelectric focusing - 2-ME 2-mercaptoethanol - PA polyacrylamide - PAGE polyacrylamide gel electrophoresis - pI isoelectric point - SDS sodium dodecyl sulfate - TMAO trimethylamine oxide - Tris Tris (hydroxymethyl)methylamine 相似文献
Solubilisierung von Fischmuskelproteinen durch Natriumdodecylsulfathaltige Puffer
Zusammenfassung Der Einfluß von Solubilisierungszeit und -temperatur, des pH-Wertes und der SDS-Konzentration des Solubilisierungspuffers auf die Extraktion von Fischmuskelproteinen wurde überprüft. Bei pH-Werten < 6 wurden die myofbrillären Proteine nur unvollständig gelöst; Solubilisierungstemperaturen von 80 bis 100 °C führten zu einem in der SDS-PAGE sichtbaren Proteinabbau. Fischmuskelproben mit hohem Formaldehydgehalt (50 mmole FA/kg Feuchtgewicht) ließen sich nur bei 100 °C vollständig solubilisieren; demgegenüber gelang die weitgehende Solubilisierung gegarter und/oder sterilisierter Produkte unter milden Bedingungen (2% SDS, 1% 2-ME, pH 8,9; 2stündiges Schütteln bei 60 °C).
Abbreviations FA formaldehyde - IEF isoelectric focusing - 2-ME 2-mercaptoethanol - PA polyacrylamide - PAGE polyacrylamide gel electrophoresis - pI isoelectric point - SDS sodium dodecyl sulfate - TMAO trimethylamine oxide - Tris Tris (hydroxymethyl)methylamine 相似文献