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  • 1
    Electronic Resource
    Electronic Resource
    Extended chain lamellae self-assembled in liquid crystal phase of soluble polydiacetylenes through chain segregation (2000)
    Springer
    Journal of polymer research 7 (2000), S. 1-6 
    Details
    ISSN: 1572-8935
    Keywords: Soluble Polydiacetylene ; Lyotropic liquid crystals ; Extended chain lamellae ; Chain segregation ; Defect core structure ; Frank elastic constant anisotropy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract This review article highlights our efforts in the past years toward a fundamental understanding of the supramolecular structures of a soluble but rigid polydiacetylene. In our earlier works we presented evidence to indicate that this polymer formed a lyotropic phase in solutions. TEM, AFM and SEM observations on solidified thin films showed an extended chain lamellar structure which is surmised to be self-assembled in the lyotropic phase through chain segregation. Our results revealed that the supramolecular structures formed are closely associated with the structures formed in the lyotropic state. Due to three attributes of rigid macromolecules at the molecular level-high molecular weight, broad molecular weight distribution, and worm-like chain conformation, the supramolecular structures observed are also greatly different from those of conventional nematics or smectics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s10965-006-0097-9
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  • 2
    Electronic Resource
    Electronic Resource
    Inversion formula of Dirichlet polynomials and the approximate functional equation of Dirichlet's L-functions (1997)
    Springer
    Archiv der Mathematik 69 (1997), S. 305-312 
    Details
    ISSN: 1420-8938
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics
    Notes: Abstract. In this note, we prove an inversion formula for Dirichlet polynomials involving a non-principal character. By using Heath-Brown's upper-bound for Dirichlet's L-functions, we are able to obtain a non-trivial upper-bound for the error term in the q aspect. As an application we obtain an approximate functional equation for Dirichlet's L-functions to the right of the critical line with a sharp error term.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s000130050125
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  • 3
    Electronic Resource
    Electronic Resource
    Iron oxide-iron phosphates as solid acid catalysts (1990)
    Springer
    Catalysis letters 6 (1990), S. 187-193 
    Details
    ISSN: 1572-879X
    Keywords: Iron oxide-iron phosphate (FeFeP) catalyst ; temperature programmed desorption (TPD) ; alumina-aluminum phosphate (AAP) catalyst ; acid catalyst
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract A series of iron oxide-iron phosphate (FeFeP) catalysts with various Fe/P ratio were prepared with the coprecipitation method. The acidic properties of these catalysts were examined by temperature-programmed-desorption (TPD) of ammonia and the dehydration reaction of isopropanol. The reaction was carried out in a continuous flow microreactor at 120–230 ° C under atmospheric pressure. Alumina-aluminum phosphates (AAPs) were also included in this study. The results of TPD of ammonia indicated that the surface of FeFeP is weakly acidic and their strength are approximately the same. The dehydration activities of these catalysts are decreased with increasing the Fe/P ratios of the samples. Correlation between the reaction rates and the Fe/P ratios indicated that the addition of phosphorus enhanced the acidities of the catalysts.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00774719
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  • 4
    Electronic Resource
    Electronic Resource
    Alumina-aluminum borates as solid acid catalysts (1991)
    Springer
    Catalysis letters 10 (1991), S. 297-304 
    Details
    ISSN: 1572-879X
    Keywords: Solid acid ; aluminum borate ; isopropanol dehydration ; temperature-programmed desorption of ammonina
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract A series of alumina-aluminum borate (AAB) catalysts with various Al/B ratios were prepared with the coprecipitation method. The surface acidic properties of these catalysts were examined by temperature-programmed-desorption (TPD) of ammonia and the dehydration reaction of isopropanol. The dehydration reaction was carried out in a continuousflow microreactor at 160 °C under atmospheric pressure. The results of TPD of ammonia indicated that the surface acidity of AAB is medium-strong. The acidic strengths are approximately the same for all the samples. However, the acid concentration is increased with increasing the boron content of the catalyst. The dehydration activities of these catalysts are increased with increasing the boron contents of the samples. The results indicated that the addition of boron even in a small amount could significantly enhance the acidities of the catalysts.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00772084
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  • 5
    Electronic Resource
    Electronic Resource
    Asymptotic expansion for the density of states of the magnetic Schrödinger operator with a random potential (1995)
    Springer
    Communications in mathematical physics 172 (1995), S. 401-425 
    Details
    ISSN: 1432-0916
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics , Physics
    Notes: Abstract We study the asymptotics for the density of states of the magnetic Schrödinger operator with a random potential. By using the methods of effective Hamiltonian, complex dilation and complex translation, we obtain in the large magnetic field limit, the asymptotic expansion for the density of states measure considered as a distribution.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02099434
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  • 6
    Electronic Resource
    Electronic Resource
    Spectrophotometric and first-derivative spectrophotometric determination of cadmium witho-hydroxybenzenediazoaminoazobenzene (HDAA) (1989)
    Springer
    Microchimica acta 97 (1989), S. 313-320 
    Details
    ISSN: 1436-5073
    Keywords: o-hydroxybenzenediazoaminoazobenzene ; cadmium determination ; spectrophotometry ; first-derivative spectrophotometry ; waste water
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The synthesis ofo-hydroxybenzenediazoaminoazobenzene (HDAA) is described. Cadmium forms with HDAA in the presence of Triton X-100 a 1∶3 complex, which gives a maximum absorption at 520nm with an apparent molar absorptivity of 1.97 × 1051 · mol−1 · cm−1 in pH 10 borax buffer solution and 1.52 × 1051 · mol−1 · cm−1 in ammoniacal medium. In both media, Beer's law is followed in the range of 0 –10 μg of cadmium in 25ml of solution and the coefficients of variation do not exceed 1.5%. A derivative method has been employed to determine cadmium in certain waste water samples without separation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01242253
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  • 7
    Electronic Resource
    Electronic Resource
    Passive Compliance from Robot Limbs and its Usefulness in Robotic Automation (1997)
    Springer
    Journal of intelligent and robotic systems 20 (1997), S. 1-21 
    Details
    ISSN: 1573-0409
    Keywords: flexible robot ; passive compliance ; stiffness matrix ; robot compliance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Robots have been traditionally used as positioning devices without muchregard to external forces experienced by the tool. This has limited furtherpotential applications of robots in automation. Most tasks that remain to beautomated require constrained robot motion and/or involve work done by therobot on the environment. Such tasks require both force and positioncontrol. The ability to control the end-effector compliance is critical tosuccessful force and position control tasks. Although the end-effectorcompliance can be actively controlled through the joint flexibilitiesprovided by the joint servos or by active force sensing, the usefulness ofhaving the minimum passive compliance in addition to active compliancecontrol can improve performance. In surface following, for example, it isnecessary to make the end-point of a robot have the right compliance toprevent jamming. The usefulness of passive compliance has been demonstratedby the use of compliance-devices on the robot end-effector such as theRemote Center Compliance. The natural compliance inherent in light weightand flexible robot structures, however, can be exploited to provide thenecessary passive compliance required. In this paper we present a novel framework for computing the end-effectorcompliance from the compliance offered by the limbs of a serial robot. Theemphasis is on the explanation of the passive end-effector complianceresulting from these structures, and particular attention is given to theuse of these results in the selection of the type of robot for a particulartask. We show examples of end-effector compliances as functions of jointconfigurations for the SCARA- and PUMA-type robots. The joint-configurationdependent end-effector compliance can be used to select the desired robotpose for the performance of a robotic task.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1007952828908
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  • 8
    Electronic Resource
    Electronic Resource
    Observed and GCM simulated decadal variability of monsoon rainfall in east China (1995)
    Springer
    Climate dynamics 11 (1995), S. 103-114 
    Details
    ISSN: 1432-0894
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract. Variability and associated mechanisms of summer rainfall over east China are identified and described using both observations and a general circulation model (GCM) simulation. The observations include two data sets: the 90-station, 1470–1988 annual drought/flood index and the 60-station, 1889–1988 monthly mean precipitation measurements. The GCM data set is a 100-year equilibrium simulation of the present climate. Spectra of the drought/flood index indicate decadal cycles which decrease from north (∼47 y) to south (∼21 y). Correlation coefficients show decadal variability in the relationship between index values along the Yangtse River valley and those over northeast and southeast China. Analysis of the measured data confirms this result; for example, the correlation was small during 1889–1918, but significantly negative during 1930–1959. When compared with precipitation measurements, the GCM better simulates monthly means and variances along the Yangtse River valley. Three distinct 30-year periods of interannual variability in summer rainfall are found over this area. During each period, rainfall is negatively correlated with spring surface temperature over a remote region and is identified with variations in a specific component of the east Asian monsoon circulation: (1) when Eurasian temperatures decrease, the thermal contrast across the Mei-Yu front increases and frontal rainfall intensities; (2) lower temperatures over the Sea of Japan/northwest Pacific Ocean are identified with enhanced easterly flow, moisture transport and rainfall; (3) when tropical east Pacific Ocean temperatures decrease, rainfall associated with the low latitude monsoon trough increases. Given that the GCM generates decadal changes in the relationship between the physical mechanisms, the east Asian monsoon and planetary general circulations and east China rainfall, future studies should focus on the predictability of these changes with the use of improved and much longer GCM simulations.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s003820050063
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  • 9
    Electronic Resource
    Electronic Resource
    Exponential decay of Green's functions for a class of long range Hamiltonians (1991)
    Springer
    Communications in mathematical physics 136 (1991), S. 35-41 
    Details
    ISSN: 1432-0916
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics , Physics
    Notes: Abstract We consider a class of long range Hamiltonians with diagonal disorder onl 2 (Z). For anyergodic potentialV with non-empty essential range, we prove the exponential decay of the Green's functions for energies in the essential range. IfV is independent identically distributed, we obtain the exponential decay of the Green's functions for all coupling constant λ〉0. Moreover the Hamiltonian has only pure point spectrum.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02096789
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  • 10
    Electronic Resource
    Electronic Resource
    Determination of lead traces in water and liqueurs by derivative atom trapping flame atomic absorption spectrometry (1997)
    Springer
    Fresenius' journal of analytical chemistry 358 (1997), S. 646-651 
    Details
    ISSN: 1432-1130
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract  A new method for the direct determination of lead traces using derivative atom trapping flame atomic absorption spectrometry (DAT-FAAS) with an improved water-cooled stainless steel trapping equipment in an air-acetylene flame was investigated. The optimum conditions concerning the sensitivity were studied. For a 1 min collection, the characteristic concentration (given as derivative absorbance of 0.0044) and the detection limit (3s) were 1.4 ng/mL and 0.27 ng/mL, respectively. This is 361 and 74-fold better than those of the conventional flame atomic absorption spectrometry (FAAS) and comparable to those of graphite furnace atomic absorption spectrometry (GFAAS). The detection limit and sensitivity of DAT-FAAS for a 3 min collection time were 2 and 3 orders of magnitude higher than those of conventional FAAS. The present method was applied to the determination of lead in water and liqueur samples with a recovery range of 94–108% and a relative standard deviation of 3.5–5.6%.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002160050484
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