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  • 11
    Electronic Resource
    Electronic Resource
    Springer
    Environmental geology 37 (1999), S. 333-339 
    ISSN: 1432-0495
    Keywords: Key words Flood ; Human impact ; Lake-level and sea-level rise ; Yangtze Delta
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences
    Notes: Abstract  Hydrological records collected from water gauge stations since the 1950s demonstrate that the Taihu lake level is rising. The average rate of the lake-level rise is 0.4–1.1 mm/year during the non-flood season, resulting directly from a rise in sea level. High rates of 3.0–5.0 mm/year of rise are even recorded during the wet season. This indicates increasing human activities such as reclamation, sluicing and embanking, which significantly hinder the expulsion of extra lake water to the coast shortly after a rainfall. Generally, the lake level of the western inlet is higher than that of the eastern outlet. However, the lake-level difference between the west and east has been diminished annually from ∼10–15 cm in the 1950s to 〈3 cm at the present time. During non-flood seasons, the lake-level difference even appears to be reversed, indicating a retrogression of the lake flow from east to west. It is predicted that the Taihu drainage basin will lose much of its natural water-expelling ability in the next 50 years as the sea level continues to rise, and retrogression will likely occur during the flood season in the near future.
    Type of Medium: Electronic Resource
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  • 12
    ISSN: 1432-1807
    Keywords: Mathematics Subject Classification (1991):35J65, 60J65
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics
    Notes: Abstract. We give sufficient conditions for the existence of positive solutions to some semilinear elliptic equations in bounded domains $D \subset \Bbb R^n$ $(n\ge 3)$ with Dirichlet boundary conditions. We impose mild conditions on the domains and lower order (nonlinear) coefficients of the equations in that the bounded domains are only required to satisfy an exterior cone condition and we allow the coefficients to have singularities controlled by Kato class functions. Our approach uses an implicit probabilistic representation, Schauder's fixed point theorem, and new a priori estimates for solutions of the corresponding linear elliptic equations. In the course of deriving these a priori estimates we show that the Green functions for operators of the form ${1\over 2} \Delta + b\cdot \nabla$ on D are comparable when one modifies the drift term b on a compact subset of D. This generalizes a previous result of Ancona [2], obtained under an $L^p$ condition on b, to a Kato condition on $|b|^2$ .
    Type of Medium: Electronic Resource
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  • 13
    Electronic Resource
    Electronic Resource
    Springer
    Mathematische Annalen 302 (1995), S. 323-357 
    ISSN: 1432-1807
    Keywords: 35J25 ; 60J60
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics
    Type of Medium: Electronic Resource
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  • 14
    Electronic Resource
    Electronic Resource
    Springer
    Mathematische Annalen 298 (1994), S. 543-556 
    ISSN: 1432-1807
    Keywords: 35J65 ; 60J65 ; 53C21
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics
    Type of Medium: Electronic Resource
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  • 15
    Electronic Resource
    Electronic Resource
    Springer
    Journal of molecular evolution 41 (1995), S. 909-919 
    ISSN: 1432-1432
    Keywords: Hemoglobins ; Chironomus ; Kiefferulus ; Gene clusters ; Molecular evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A genomic clone containing hemoglobin genes was isolated from a species of the chironomid genus Kiefferulus. Eight genes, including an apparent pseudogene, were sequenced and the amino acid sequences of the putative proteins were determined. By comparison to the previously described hemoglobins in the sister-genus Chironomus, they were identified as members of the dimeric Hb VIIB group. The results indicate that the existence of clusters of hemoglobin genes may be a common feature in chironomids and not just confined to Chironomus. The Kiefferulus genes show greatest similarity of amino acid sequence to Hb VIIB-7 from the Chironomus cluster. The results suggest that the ancestral cluster contained at least two gene types, one of which gave rise to VIIB-7 and the Kiefferulus genes while the other gave rise to the other Chironomus VIIB genes. Both clusters appear to have increased in size by duplication or unequal crossing over since the separation of the genera. It also appears that an unrelated gene present in the Chironomus cluster, Hb-Y, arose from a completely independent origin with no apparent equivalent gene anywhere in the genome of Kiefferulus or some other Chironomus species.
    Type of Medium: Electronic Resource
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  • 16
    Electronic Resource
    Electronic Resource
    Springer
    Heat and mass transfer 28 (1993), S. 243-249 
    ISSN: 1432-1181
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Description / Table of Contents: Zusammenfassung Mit Hilfe der Naphthalin-Sublimationstechnik werden die Wärmeübergangs- und Druckverlustcharakteristiken in quer zur voll ausgebildeten Strömung bei berippten Ringkanälen experimentell ermittelt und Korrelationen zur Berechnung des Wärmeübergangskoeffizienten bei variablen InnendurchmesserD 0 des umschließenden Rohres angegeben. Ferner wird eine charakteristische Reynolds-Zahl vorgeschlagen, über die sich der dominierende Einfluß der Querrippen erfassen läßt. Es zeigte sich, daß der InnendurchmesserD 0 den Druckverlust wesentlich mehr beeinflußt als den Wärmeübergang. Auch wurde die Abhängigkeit des Gesamt-Übertragungsverhaltens vonD 0 bei gleicher Strömungsgeschwindigkeit bzw. Volumenstromdichte ermittelt. Es zeigte sich, daß die Ausbildung des Strömungsprofils bei Einlaufströmung den Wärmeübergang signifikant beeinflußt und deshalb im Experiment zu berücksichtigen ist.
    Notes: Abstract The characteristics of heat transfer and pressure drop have been experimentally studied for the fully developed concentric annular flow with transverse fins normal to the flow direction by the naphthalene sublimation technique. Correlations for calculating the heat transfer coefficient with different inner diametersD 0 of the outer tube are presented. A “characteristic Reynolds number” has been proposed, by which the predominant role of the transverse fins can be evaluated. It has been indicated that the inner diameterD 0 has much more effect on pressure drop than on heat transfer. The effect ofD 0 on the overall performance is also compared under the same flow velocity or flow rate. It has been found that the effect of developing flow on heat transfer is significant and should be taken into account during experiment.
    Type of Medium: Electronic Resource
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  • 17
    Electronic Resource
    Electronic Resource
    Springer
    Applied physics 43 (1987), S. 1-7 
    ISSN: 1432-0649
    Keywords: 68.15.+e ; 78.65.−s ; 78.20.Nv
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The photoacoustic generation of plane acoustic waves in strongly absorbing or opaque liquids by pulsed laser radiation is discussed both experimentally and theoretically. The regimes of a confined and a free surface of the liquid are considered. The model which takes the temporal shape of the laser pulses applied in the experiments into account, implies that spectroscopic studies are feasible with direct photoacoustic generation and detection also for opaque liquids. The experiments are performed with a tunable hybrid CO2 laser and piezoelectric detection. For the first time liquid/liquid interfaces are studied by this technique. We demonstrate that the presence of an absorbing liquid film with a thickness of 〉1 μm on the surface of another liquid amplifies the acoustic signal which is detected in the bottom liquid. The enhancement depends on the thickness and the optical and thermal properties of the film medium. The surface layer can be analyzed on the basis of the photoacoustic spectrum. It is also shown that this non-contact method is surface-film selective and should thus prove useful for pollution analysis of liquid surfaces.
    Type of Medium: Electronic Resource
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  • 18
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 41 (1991), S. 379-382 
    ISSN: 1432-1041
    Keywords: Codeine ; paracetamol ; codeine-6-glucuronide ; pharmacokinetics ; metabolism ; partial clearance ; drug interaction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Plasma and urine concentrations of codeine and its measurable metabolites were determined by HPLC in six healthy subjects after a single 30 mg oral dose of codeine either alone or after 7 doses of 1 g paracetamol 8 hourly. After codeine alone, the t1/2 (h), AUC (μmol·l−1·h) and CLR (ml·min−1) for codeine were 2.2, 0.81, and 252 respectively. These were not significantly altered by paracetamol: 2.2, 0.84, and 291 respectively. For codeine-6-glucuronide the values were 2.4, 22.0, and 29.7 respectively. These were not significantly different from those after codeine plus paracetamol: 2.4, 21.9, and 39.6. There were no significant differences between the two treatments in the apparent partial clearances (ml·min−1) of codeine to morphine (88 codeine alone, 70 codeine plus paracetamol), to norcodeine (71 codeine alone, 88 codeine plus paracetamol), and to codeine-6-glucoronide (820 codeine alone, 1022 codeine plus paracetamol). The urinary excretion of codeine-6-glucuronide, morphine, norcodeine, and codeine were not significantly different between the two treatments.
    Type of Medium: Electronic Resource
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  • 19
    Electronic Resource
    Electronic Resource
    s.l. ; Stafa-Zurich, Switzerland
    Advanced materials research Vol. 15-17 (Feb. 2006), p. 762-767 
    ISSN: 1662-8985
    Source: Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Surface graphitization is a well known defect that occurs when low carbon steel strip isbatch annealed. A small addition of chromium (about 0.04 wt %) can be used to minimize thesurface graphitization. However chromium and some other alloy elements, such as manganese usedin this class of steel, have higher affinities for oxygen than iron. Therefore it is possible for them tobe oxidized during batch annealing in a reducing environment to iron. Selective oxidation of thesetwo elements gives rise to a risk of forming different surface defects that may affect the quality ofthe tinned surface. The edge defect is characterized as a region of low reflectivity on the tin plateproduct caused by grain boundary precipitates. A porous tin coating with a dull appearance isproduced in the affected areas. Not only are the aesthetical values of the finished tin plate productaffected but the corrosion resistance is also reduced.In this investigation surface oxides formed at grain boundary of low carbon steels annealed at700°C in 5% hydrogen 95% nitrogen atmosphere were characterized using scanning electronmicroscopy and transmission electron microscopy. Two different oxide particles (Fe,Mn)O andMnCr2O4 were observed at the grain boundaries with the former five-fold coarser than the latter. Itwas found at the annealing temperature of 700°C, that the mean particle size of the (Fe,Mn)Odepends on the manganese content, while the mean particle size, and distribution of the MnCr2O4was dependent on chromium, but independent of manganese. The coarse (Fe,Mn)O precipitatespose no potential risks to electrolytic tinning as they will be removed by the pickling operation priorto tinning. Controlling the chromium content of the steel can minimize the potential risks posed bythe MnCr2O4 to the quality of electrolytic tinning
    Type of Medium: Electronic Resource
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  • 20
    ISSN: 0992-7689
    Keywords: Flux asymmetry ; Net flux intensity ; GEOS 2 ; Energetic particles
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract The flux asymmetries measured by spectrometers on board spacecraft contain information on particle parameters. The net flux intensity (NFI) method provides a tool to evaluate these parameters. The NFI method is valid when both the spin period of the spacecraft and the time resolution of the particle spectrometers are much shorter than the characteristic time-scale of the particle flux variations. We apply the NFI analysis to the flux asymmetry measurements made by GEOS 2 at the nightside geosynchronous orbit in the late substorm growth phase. The cross-tail current of energetic ions, their pressure gradient and average drift velocity, as well as a field-aligned flows are investigated. Current disruption at substorm onset and the –convection surge” mechanism during dipolarization of the magnetic field are directly observed.
    Type of Medium: Electronic Resource
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