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  • 1
    Electronic Resource
    Electronic Resource
    Polymer–Ceramic Conversion of Liquid Polyaluminasilazanes for SiAlCN Ceramics (2005)
    Oxford, UK : Blackwell Science Inc
    Journal of the American Ceramic Society 88 (2005), S. 0 
    Details
    ISSN: 1551-2916
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Liquid-phased polyaluminasilazanes were synthesized by simply reacting a liquid polyureasilazane with aluminum isopropoxide. The reaction was studied by Fourier-transform infrared spectrometry (FTIR) and mass spectroscopy. The resultant polyaluminasilazanes were then pyrolysized to form amorphous SiAlCN ceramics at 1000°C in flowing N2. The structural evolution during pyrolysis was studied using solid-state NMR and FTIR. Spectral analysis revealed that the amorphous structures of the ceramics consisted of SiC2N2 and SiCN3 as major building units, small amounts of SiC3N and SiN4 units, and penta- or hexa-coordinated aluminum with nitrogen. Such units were connected with each other through C−C/C=C bonds or by shearing N to form network structures. The results also revealed that the relative amount of these units strongly depended on the Al content.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1551-2916.2005.00481.x
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  • 2
    Electronic Resource
    Electronic Resource
    Synthesis, Characterization, and Optical Properties of Pristine and Doped Yttrium Aluminum Garnet Nanopowders (2005)
    Oxford, UK : Blackwell Science Inc
    Journal of the American Ceramic Society 88 (2005), S. 0 
    Details
    ISSN: 1551-2916
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Pristine, Si-doped, and Si/Nd-codoped yttrium aluminum garnet (YAG) nanoparticles were synthesized by pyrolysis of complex compounds of aluminum and yttrium with triethanolamine. It was found that the coexistence of Si4+ and Nd3+ increased the solubility of both ions and promoted the formation of YAG phase. Single-phase, nanocrystalline Si/Nd:YAG powders were obtained at calcination temperatures as low as 920°C. The optical behavior of the Si/Nd:YAG nanopowders was similar to that of single-crystal Nd:YAG.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1551-2916.2005.00071.x
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  • 3
    Electronic Resource
    Electronic Resource
    Oxidation of Polymer-Derived SiAlCN Ceramics (2005)
    Oxford, UK : Blackwell Science Inc
    Journal of the American Ceramic Society 88 (2005), S. 0 
    Details
    ISSN: 1551-2916
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: The oxidation behavior of polymer-derived amorphous SiAlCNs was studied in the temperature range of 900°–1200°C. The results revealed that while at 900°C the oxidation of the SiAlCNs follows typical parabolic kinetics, at higher temperatures the oxidation rates of the materials decrease with annealing time. Long-term oxidation rate of the SiAlCNs is much lower than the lowest values reported for chemical vapor deposition of SiC and Si3N4. Structures of the oxide scales were studied using solid-state nuclear magnetic resonance. We proposed that oxide scales formed for the SiAlCNs possess a unique network structure of the oxide scale in which aluminum atoms block the path of oxygen diffusion, thus lowering the oxidation rates. Such a unique structure was likely formed gradually with annealing time, leading to a continuous decrease in oxidation rate.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1551-2916.2005.00542.x
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  • 4
    Electronic Resource
    Electronic Resource
    Oxidation Behavior of a Fully Dense Polymer-Derived Amorphous Silicon Carbonitride Ceramic (2004)
    Westerville, Ohio : American Ceramics Society
    Journal of the American Ceramic Society 87 (2004), S. 0 
    Details
    ISSN: 1551-2916
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: The oxidation behavior of a polymer-derived amorphous silicon carbonitride (SiCN) ceramic was studied at temperature range of 900°–1200°C using fully dense samples, which were obtained using a novel pressure-assisted pyrolysis technique. The oxidation kinetics was investigated by measuring the thickness of oxide layers. The data were found to fit a typical parabolic kinetics. The measured oxidation rate constant and activation energy of the SiCN are close to those of CVD and single-crystal SiC. The results suggest that the oxidation mechanism of the SiCN is the same as that of SiC: oxygen diffusion through a silica layer.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1551-2916.2004.00483.x
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  • 5
    Electronic Resource
    Electronic Resource
    Axillary osmidrosis treated by partial removal of the skin and subcutaneous tissue en bloc and apocrine gland subcision (2001)
    Oxford, UK : Blackwell Science Ltd
    International journal of dermatology 40 (2001), S. 0 
    Details
    ISSN: 1365-4632
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: AbstractBackground  Axillary osmidrosis can be treated with many methods, but local surgery is the treatment of choice.Methods  Forty-three patients (32 females and 11 males, average age 20.3 years) were treated by partial removal of the skin and subcutaneous tissue en bloc and follicular clipping of the adjacent area. All operations were performed with local anesthesia in an outpatient setting.Results  Follow-up ranged from 2 to 47 months (mean: 13.4 months). Forty-one patients (95%) had good results, two (5%) were fair, and none were poor. No recurrences were seen. The wound complication rate was 3.5% for axillae and 7% for patients. There were no scar contractures or limitations of arm abduction.Conclusion  This combined surgical method can eliminate malodor and has a low wound complication and recurrence rate. Though the transient and conspicuous scar is the chief drawback of this method, it is a simple, safe, effective and inexpensive method for treating axillary osmidrosis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1365-4362.2001.01291.x
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  • 6
    Electronic Resource
    Electronic Resource
    Proposing the content perception theory for the online content industry - a structural equation modeling (2004)
    Bingley : Emerald
    Industrial management & data systems 104 (2004), S. 469-489 
    Details
    ISSN: 0263-5577
    Source: Emerald Fulltext Archive Database 1994-2005
    Topics: Computer Science , Economics
    Notes: This study chooses the content perception perspective to develop a theoretical model portraying the psychological activities of Web surfers exposed to content Web sites. After collecting 549 empirical observations in a controlled lab environment, tests the theoretical relationships by using the structural equation modelling (SEM) technique. The results strongly indicate that effective content perceptual dimensions can help content Web surfers to develop positive attitudes toward content sites, which in turn induce favorable behavioral outcomes such as frequent site usage and loyalty. Such a proposed theoretical model not only has the potential to enrich the theoretical underpinning of Internet studies but also presents a practical framework to guide content strategy formulations for the online content industry. Detailed implications for both managerial research and practice are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1108/02635570410543780
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  • 7
    Electronic Resource
    Electronic Resource
    Analytical Calculation of the Light Extraction Efficiency of Micro Cavities Light-Emitting Diodes (2007)
    s.l. ; Stafa-Zurich, Switzerland
    Key engineering materials Vol. 364-366 (Dec. 2007), p. 98-103 
    Details
    ISSN: 1013-9826
    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: Using TracePro® Monte-Carlo ray-tracing simulations, this paper investigates theimproved light extraction efficiency (LEE) obtained by patterning the surface and/or substrate ofGaN LEDs with unique three-dimensional micro-cavity patterns. The simulations commence byconsidering the case of a sapphire-based GaN LED. The effects on the LEE of the micro-cavitydimensions, the absorption coefficient of the active layer, the point source location, and the chipdimensions are systematically examined. Subsequently, the LEE performance of the sapphire-basedGaN LED is compared with that of a thin-GaN LED for various surface texturing strategies. Ingeneral, the results show that patterning either the surface or the substrate of the LED structureprovides an effective improvement in the LEE of both the sapphire-based GaN LED and the thin-GaN LED. For both LED structures, the maximum LEE enhancement is obtained by patterning boththe upper surface of the LED and the substrate surface. However, the simulation results indicate thatthe improvement obtained in the LEE is the result primarily of pattering the upper surface of theLED
    Type of Medium: Electronic Resource
    URL: http://www.tib-hannover.de/fulltexts/2011/0528/01/56/transtech_doi~10.4028%252Fwww.scientific.net%252FKEM.364-366.98.pdf
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  • 8
    Electronic Resource
    Electronic Resource
    A Novel Time Based Current Compensator for LED Back Light Modules (2007)
    s.l. ; Stafa-Zurich, Switzerland
    Key engineering materials Vol. 364-366 (Dec. 2007), p. 377-382 
    Details
    ISSN: 1013-9826
    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: The paper proposes a novel time based brightness compensation circuit for LED backlight modules. The brightness of LED decays while running under constant current drivencondition. We have designed a suitable controller to compensate the driving currents to maintain thebrightness. The compensation data were calculated from the relative luminous efficiency – timecurve provided by the LED manufacturer and were stored in the microprocessor. -The embeddedsystem used the running time of the LED in the back light module as an independent variable fortuning the driving current. The experiment results showed that the brightness of different operatingtimes’ LED arrays can be held almost the same as the new ones
    Type of Medium: Electronic Resource
    URL: http://www.tib-hannover.de/fulltexts/2011/0528/01/56/transtech_doi~10.4028%252Fwww.scientific.net%252FKEM.364-366.377.pdf
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  • 9
    Electronic Resource
    Electronic Resource
    The influence of topography on the nonlinear interaction of Rossby waves in the barotropic atmosphere (1994)
    Springer
    Applied mathematics and mechanics 15 (1994), S. 585-594 
    Details
    ISSN: 1573-2754
    Keywords: topography ; Rossby waves ; non-resonant parametric instability
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Mathematics , Physics
    Notes: Abstract In the frame of weak nonlinear theory, a set of equations depicting the nonlinear interactions of barotropic Rossby waves are derived, the topography and Ekman friction are involved in the equations. Starting from the equations, we investigate the interaction of three Rossby wave packets with narrow-spread in wave vectors. When an intense primary pump Rossby wave with amplitude larger than a threshold propagates through the atmosphere, the amplitude of one Rossby wave packet with scale greater than the primary one and one Rossby wave packet with scale smaller than the primary one grow exponentially through three wave interactions, the intrinsic frequencies of the secondary waves can be varied. The threshold and the variation of the intrinsic frequencies of the secondary waves are related to the Ekman friction frequency dismatch, topography and spatial evolution of the secondary Rossby wave packets.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02450772
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  • 10
    Electronic Resource
    Electronic Resource
    Molecular mechanics (MM3) calculations on azoxy compounds (1994)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 15 (1994), S. 1446-1460 
    Details
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: The MM3 force field has been extended to include azoxy compounds and also the related amine oxides, both aliphatic and aromatic. The structures of nine molecules were all well fit. The heats of formation for the aliphatic compounds were also well fit, and the vibrational spectra of eight compounds were also fit to the accuracy expected for such calculations. Because many of the experimental data needed to derive the force field were either lacking or were inadequate, ab initio calculations on structures, optimized at the MP2/6-31G* level, were used as needed. © 1994 by John Wiley & Sons, Inc.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcc.540151214
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