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  • PACS: 42.60; 81.60  (5)
  • Cell & Developmental Biology  (3)
  • global convergence  (3)
  • 23.20.Lv  (2)
  • 1
    Electronic Resource
    Electronic Resource
    Dual-beam ablation of fused quartz using 266 nm and VUV lasers with different delay-times (1997)
    Springer
    Applied physics 64 (1997), S. 477-481 
    Details
    ISSN: 1432-0630
    Keywords: PACS: 42.60; 81.60
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s003390050504
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  • 2
    Electronic Resource
    Electronic Resource
    High-quality and high-efficiency machining of glass materials by laser-induced plasma-assisted ablation using conventional nanosecond UV, visible, and infrared lasers (1999)
    Springer
    Applied physics 69 (1999), S. S879 
    Details
    ISSN: 1432-0630
    Keywords: PACS: 42.60; 81.60
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract. This paper reports the micromachining of fused quartz and Pyrex glass by laser-induced plasma-assisted ablation (LIPAA) using a conventional nanosecond laser at wavelengths 266 nm, 532 nm, and 1064 nm, respectively. High-quality surface structuring can be achieved at each of these wavelengths. The micrograting formed has periods of 14 μm at 266 nm, 20 μm at 532 nm, and 30 μm at 1064 nm, respectively. The ablation rate using a 266 nm laser is much larger than that at longer wavelengths. The ablation thresholds of laser fluence are 0.7 J/cm2 for 266 nm, 1.5 J/cm2 for 532 nm and 3.7 J/cm2 for 1064 nm, respectively. The 532 nm and 1064 nm lasers enable hole drilling in 0.5 and 2.0-mm thick fused quartz and Pyrex glass substrates of about 0.7–0.8 mm in diameter. However, the less destructive through channel can be only formed in Pyrex glass by using a 532 nm laser.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s003390051551
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  • 3
    Electronic Resource
    Electronic Resource
    First identification of high spin states in160Lu (1995)
    Springer
    The European physical journal 351 (1995), S. 241-242 
    Details
    ISSN: 1434-601X
    Keywords: 23.20.Lv ; 25.70.Gh ; 27.70.+q
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract A rotational band of160Lu was identified for the first time through the144Sm(19F,3n)160Lu reaction with a beam energy of 90 MeV. A γ-γ-BGO coincidence experiment was performed using five HpGe-BGO Compton-Suppressed spectrometers and a 14 elements ball of BGO detectors. The highest spin of the band with π9/2−[514]⊗v1/2+[660] could be pushed up to 21−, and it shows the feature of an anomalous signature splitting.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01290902
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  • 4
    Electronic Resource
    Electronic Resource
    Study of the yrast band in the doubly odd156Tm (1995)
    Springer
    The European physical journal 352 (1995), S. 115-116 
    Details
    ISSN: 1434-601X
    Keywords: 23.20.Lv ; 27.70.+q
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The yrast band in the doubly odd156Tm nucleus was studied through144Sm(19F,2p5n)156Tm reaction at beam energy of 105MeV. Several high-spin states of156Tm were identified and the highest spin of the band with configurationπ7/2−[523] ⊗v1/2+[660] could be built up to spin 25ħ. The level structure shows the onset of a non- or weak collectivity which generally appears at neutron number of 87 in neutron-deficient rare-earth nuclei.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01298894
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  • 5
    Electronic Resource
    Electronic Resource
    High-speed machining of glass materials by laser-induced plasma-assisted ablation using a 532-nm laser (1998)
    Springer
    Applied physics 67 (1998), S. 499-501 
    Details
    ISSN: 1432-0630
    Keywords: PACS: 42.60; 81.60
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: + :YAG laser (532 nm). The plasma generated from a silver (Ag) target by the laser irradiation effectively assists in ablation of the fused quartz substrate by the same laser beam, although the laser beam is transparent to the substrate. A grating with a cross-sectional shape like a square-wave (period ≈ 20 μm) is achieved using the mask projection technique. The ablation rate reaches several tens nm/pulse. In addition, LIPAA is applied to high-speed hole drilling (700 μm in diameter) of fused-quartz (0.5 mm thick) and Pyrex glass (0.5 mm thick).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s003390050810
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  • 6
    Electronic Resource
    Electronic Resource
    Laser-induced plasma-assisted ablation of fused quartz using the fourth harmonic of a Nd+:YAG laser (1998)
    Springer
    Applied physics 67 (1998), S. 545-549 
    Details
    ISSN: 1432-0630
    Keywords: PACS: 42.60; 81.60
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: + :YAG laser (266 nm) is reported. With the assistance of plasma resulting from laser irradiation on a metal target, the fused-quartz substrate is easily etched by the 266-nm laser beam in spite of the fact that the substrate is transparent to this wavelength. In contrast, no ablation takes place without the metal target, but damage is generated on the substrate surface. The ablated region is observed by optical microscopy and scanning probe microscopy (SPM), which reveal a fine grating structure (line spacing of 20 μm) without any severe damage. A series of experiments on the dependence of the ablation rate and the threshold laser fluence on ablation parameters, such as laser fluence, the number of pulses, and the distance between the fused quartz and the metal target is performed. On the basis of the results, three possible mechanisms of direct plasma interaction, plasma heating, and metal film deposition are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s003390050819
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  • 7
    Electronic Resource
    Electronic Resource
    Dual-beam ablation of fused silica by multiwavelength excitation process using KrF excimer and F2 lasers (2000)
    Springer
    Applied physics 71 (2000), S. 23-26 
    Details
    ISSN: 1432-0630
    Keywords: PACS: 42.60; 81.60
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract. A new technique of dual-beam laser ablation of fused silica by multiwavelength excitation process using a 248-nm KrF excimer laser (ablation beam) coupled with a 157-nm F2 laser (excitation beam) in dry nitrogen atmosphere is reported. The dual-beam laser ablation greatly reduced debris deposition and, thus, significantly improved the ablation quality compared with single-beam ablation of the KrF laser. High-quality ablation can be achieved at the delay times of KrF excimer laser irradiation shorter than 10 ns due to a large excited-state absorption. The ablation rate can reach up to 80 nm/pulse at the fluence of 4.0 J/cm2 for the 248-nm laser and 60 mJ/cm2 for the F2 laser. The ablation threshold and effective absorption coefficient of KrF excimer laser are estimated to be 1.4 J/cm2 and 1.2×105 cm-1, respectively.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s003390050020
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  • 8
    Electronic Resource
    Electronic Resource
    Scaled Optimal Path Trust-Region Algorithm (1999)
    Springer
    Journal of optimization theory and applications 102 (1999), S. 127-146 
    Details
    ISSN: 1573-2878
    Keywords: Trust-region methods ; unconstrained optimization ; Bunch–Parlett factorization ; optimal paths ; global convergence ; local convergence rates
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics
    Notes: Abstract Trust-region algorithms solve a trust-region subproblem at each iteration. Among the methods solving the subproblem, the optimal path algorithm obtains the solution to the subproblem in full-dimensional space by using the eigenvalues and eigenvectors of the system. Although the idea is attractive, the existing optimal path method seems impractical because, in addition to factorization, it requires either the calculation of the full eigensystem of a matrix or repeated factorizations of matrices at each iteration. In this paper, we propose a scaled optimal path trust-region algorithm. The algorithm finds a solution of the subproblem in full-dimensional space by just one Bunch–Parlett factorization for symmetric matrices at each iteration and by using the resulting unit lower triangular factor to scale the variables in the problem. A scaled optimal path can then be formed easily. The algorithm has good convergence properties under commonly used conditions. Computational results for small-scale and large-scale optimization problems are presented which show that the algorithm is robust and effective.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1021846613163
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  • 9
    Electronic Resource
    Electronic Resource
    Projected quasi-Newton algorithm with trust region for constrained optimization (1990)
    Springer
    Journal of optimization theory and applications 67 (1990), S. 369-393 
    Details
    ISSN: 1573-2878
    Keywords: Two-sided projected Hessians ; trust regions ; differentiable penalty functions ; global convergence ; two-step Q-superlinear rate ; constrained optimization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics
    Notes: Abstract In Ref. 1, Nocedal and Overton proposed a two-sided projected Hessian updating technique for equality constrained optimization problems. Although local two-step Q-superlinear rate was proved, its global convergence is not assured. In this paper, we suggest a trust-region-type, two-sided, projected quasi-Newton method, which preserves the local two-step superlinear convergence of the original algorithm and also ensures global convergence. The subproblem that we propose is as simple as the one often used when solving unconstrained optimization problems by trust-region strategies and therefore is easy to implement.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00940481
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  • 10
    Electronic Resource
    Electronic Resource
    Globally Convergent Inexact Generalized Newton Method for First-Order Differentiable Optimization Problems (2000)
    Springer
    Journal of optimization theory and applications 106 (2000), S. 551-568 
    Details
    ISSN: 1573-2878
    Keywords: nonsmooth optimization ; inexact Newton methods ; generalized Newton methods ; global convergence ; superlinear rate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics
    Notes: Abstract Motivated by the method of Martinez and Qi (Ref. 1), we propose in this paper a globally convergent inexact generalized Newton method to solve unconstrained optimization problems in which the objective functions have Lipschitz continuous gradient functions, but are not twice differentiable. This method is implementable, globally convergent, and produces monotonically decreasing function values. We prove that the method has locally superlinear convergence or even quadratic convergence rate under some mild conditions, which do not assume the convexity of the functions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1004605428858
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