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  • 1
    Electronic Resource
    Electronic Resource
    Relationship between optical and structural properties of hydrogenated amorphous silicon (1989)
    Springer
    Applied physics 48 (1989), S. 295-304 
    Details
    ISSN: 1432-0630
    Keywords: 61.40 ; 73.60 ; 78.30
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract A series of experimental studies has been made on the relationship between optical and structural properties of hydrogenated amorphous silicon (a-Si:H) prepared under various conditions. It has been clarified by analysing the results that the shape of the energy spectrum near the band edge and the distribution of the valence-band tail states depend primarily on the structural disorder of the Si network in a-Si:H. On the other hand, the total content and the bonding mode of bonded hydrogen have little effects on these electronic properties of a-Si:H. It has also been found that the distribution of the valenceband tail states might be related to other unidentified factor(s) besides the structural disorder. The present results have been compared with those of the previous experimental and theoretical studies.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00618889
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  • 2
    Electronic Resource
    Electronic Resource
    Theoretical analysis of trapping and recombination of photogenerated carriers in amorphous silicon solar cells (1985)
    Springer
    Applied physics 37 (1985), S. 153-164 
    Details
    ISSN: 1432-0630
    Keywords: 86.30 ; 72.40 ; 73.60
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract We have made theoretical studies on the trapping and recombination of photogenerated carriers in hydrogenated amorphous silicon (a-Si∶H) p-i-n solar cells. We discuss in detail the following points: 1) The limitations of the assumptions in the previous analysis. It has been clarified that the single-level Shockley-Read-Hall model for carrier recombination and the treatment of trap occupation in terms of quasi-Fermi levels are inadequate for exact analysis. 2) The superlinear dependence of carrier recombination rate on the free-carrier density which can explain the enhancement of photo-induced changes ina-Si∶H under high intensity light. 3) The estimation of capture cross section of the tail states ina-Si∶H. We show that the charged and neutral tail states have rather small capture cross sections of less than 10−16 cm2 and of less than 10−19 cm2, respectively. 4) The effect of the recombination of photogenerated (PG) carriers at the p/i and the n/i interfaces. We estimate the recombination velocityS of PG carriers at these interfaces to be about 103 cm/s. It has been also clarified that the decrease inS is effective to improve the cell performance, especially the open circuit voltage.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00617500
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  • 3
    Electronic Resource
    Electronic Resource
    Validity of quasi-static capacitance-voltage measurements applied to hydrogenated amorphous silicon diodes (1986)
    Springer
    Applied physics 40 (1986), S. 171-176 
    Details
    ISSN: 1432-0630
    Keywords: 73.60 ; 71.20 ; 86.30
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract We have reexamined the validity of quasi-static capacitance-voltage (C-V) measurements when applied to hydrogenated amorphous silicon (a-Si: H) diodes. Displacement currents with the application of a linear ramp voltage to an a-Si:H Schottky diode exhibit a slow response with time constants ranging 0.1–1 s which cannot be measured completely by the conventional measurements. The measured capacitance and the effective density of gap states obtained from the measurement depend on the timing of current observation even when the small value of the order of 0.01 V/s is chosen for the ramp rate. We propose a possible means to realize the true quasi-staticC-V measurement of a-Si:H diodes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00617400
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  • 4
    Electronic Resource
    Electronic Resource
    Feasible solutions for optimization problems involving unresolved peaks using retention prediction and information theory (1991)
    Springer
    Chromatographia 31 (1991), S. 554-560 
    Details
    ISSN: 1612-1112
    Keywords: Chromatography, general ; Optimization ; Information theory ; Kalman filter ; Retention prediction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary This paper treats optimization problems involving unresolved component peaks with the information measure FUMI (Function ofMutualInformation) as a criterion. The LC analysis of 20 PTH-amino acids is taken as an example of the optimization of mobile phase composition, column length and temperature. The quantitative structure-retention relationship is adopted for the simulation and for the establishment of feasible solutions of the problems. The applicability of the FUMI theory is further extended by solving the above optimization problems.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02279475
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  • 5
    Electronic Resource
    Electronic Resource
    Mathematical structure of chromatographic optimization based on information theory: II. Analytical role of chromatographic variables (1991)
    Springer
    Chromatographia 31 (1991), S. 374-380 
    Details
    ISSN: 1612-1112
    Keywords: Chromatography, general ; Optimization ; Information theory ; Kalman filter
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The influence of variables Z (mobile phase composition X, column length L, etc.) on chromatographic analysis is studied in terms of the two separate stages of the whole optimization process. In the first stage, peak separation is the central concern and the resolution Rs can be related to Shannon information φj of peak $$j:\frac{{\partial \phi _j }}{{\partial Z}} = C\frac{{\partial R_s }}{{\partial Z}}$$ where C is a coefficient (〉0). In the second stage, only chromatograms with no peak overlap are considered and Rs is not connected with φj. The analytical role of Z is evaluated by comparing the signs and magnitudes of the derivatives of the information, φj, and its transmission rate, ϑj, with respect to Z in both stages.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02262195
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  • 6
    Electronic Resource
    Electronic Resource
    Mathematical structure of chromatographic optimization based on information theory: I. Effect of mobile phase composition on precision (1991)
    Springer
    Chromatographia 31 (1991), S. 367-373 
    Details
    ISSN: 1612-1112
    Keywords: Chromatography, general ; Optimization ; Information theory ; Kalman filter
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The influence of mobile phase composition X on the precision of liquid-chromatographic analysis is interpreted in terms of the derivate of the mutual information φ for peak j with respect to X, dφj/dX. The sign and magnitude of dφj/dX depend on the operational conditions of X or on the details of chromatograms (e.g., resolutions Rs), but dφj/dX always indicates the direction of X toward more information φj. The sensitivity function sj(=1/(kj+1)) is examined on the basis of information theory. Optimization is formulated as a nonlinear programming problem.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02262194
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  • 7
    Electronic Resource
    Electronic Resource
    Information theory of optimization in chromatography: Optimum peak separation and dependency on peak area (1991)
    Springer
    Chromatographia 32 (1991), S. 233-237 
    Details
    ISSN: 1612-1112
    Keywords: Chromatography, general ; Optimization ; Information theory ; Kalman filter
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary If a peak (j=2) moves along the time axis of a chromatogram with no change in the position τ1 of the other peak (j=1) or in areas A1 and A2, the optimum separation, Řs, is defined as the resolution Rs which provides the maximum information, called FUMI, among all possible positions τ2 of the peak (τ2≥τ1). This paper demonstrates that optimum separation, Řs, of chromatographic peaks critically depends on the peak areas. As the area ratio A2/A1 of overlapped peaks increases, greater separation (higher resolution Rs) is needed to obtain maximum information. The quantitative relationship between Řs and A2/A1 is derived by computer simulation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02276246
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  • 8
    Electronic Resource
    Electronic Resource
    Optimization of precision and throughput in micellar elektrokinetic chromatography (1993)
    Springer
    Chromatographia 37 (1993), S. 149-155 
    Details
    ISSN: 1612-1112
    Keywords: General chromatography ; Optimization ; Information theory ; Optimized resolution ; MEKC
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The influences of micelle concentration, applied voltage and temperature on the precision and throughput of analysis are studied. The precision is the Shannon mutual information and the throughput is the transmission speed of the information (=information divided by analysis time). The dependence of the precision and throughput on the peak shape, resolution Rs and run time is examined in various operating conditions. The most precise analysis (indicated by the maximum of the information) and the highest throughput analysis (the maximum of the transmission speed) are selected and their analytical importance is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02275852
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  • 9
    Electronic Resource
    Electronic Resource
    Information theory of optimization in chromatography: Correlation of information functions in optimization (1990)
    Springer
    Chromatographia 29 (1990), S. 446-448 
    Details
    ISSN: 1612-1112
    Keywords: Chromatography, general ; Optimization ; Information theory ; Kalman filter
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The quality of a chromatogram can be numerically characterized by a set of the information functions (Φ, δΦ, ΔΦ) where Φ is called FUMI, δΦ is the information loss, and ΔΦ is the information variation. A chromatogram can be expressed as a point in the space (Φ, δΦ, ΔΦ) and change in a parameter such as wavelength shift draws a curved line in the space. Optimization processes of different parameters display different patterns of lines in the space. Two types of optimization in the space are demonstrated for the analysis of an antipyretics mixture by liquid chromatography. The method used here may lead to a new aspect of optimization theory in chromatography.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02261392
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