Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Experimental investigation and computational modeling of hot filament diamond chemical vapor deposition (1997)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 107 (1997), S. 5918-5928 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: A joint investigation has been undertaken of the gas-phase chemistry taking place in a hot-filament chemical vapor-deposition (HFCVD) process for diamond synthesis on silica surfaces by a detailed comparison of numerical modeling and experimental results. Molecular beam sampling using quadrupole mass spectroscopy and resonance-enhanced multiphoton ionization time of flight mass spectroscopy (REMPI-TOF-MS) has been used to determine absolute concentrations of stable hydrocarbons and radicals. Resulting species of a CH4/H2, a CH4/D2 (both 0.5%/99.5%) and a C2H2/H2 (0.25%/99.75%) feedgas mixture were investigated for varying filament and substrate temperatures. Spatially resolved temperature profiles at various substrate temperatures, obtained from coherent anti-Stokes Raman spectroscopy (CARS) of hydrogen, are used as input parameters for the numerical code to reproduce hydrogen atom, methyl radical, methane, acetylene, and ethylene concentration profiles in the boundary layer of the substrate. In addition, the concentration of vibrationally excited hydrogen is determined by CARS. Results reveal only qualitative agreement between measured data and simulations, concerning concentrations of stable species and radicals probed near the surface, on filament and substrate temperature dependence, respectively. Hydrogen and deuterium experiments show similar behaviour for all species. In the case of CH4 as feedgas the model describes measured concentration profiles of CH3, CH4, and C2H2 qualitatively well. Large differences between model and experiment occur for hydrogen atoms (factor of 2) and C2H4 (factor of 3). For acetylene as feedgas the model is not able to give any predictions because no conversion of C2H2 is seen in the model in contrast to the experiment. © 1997 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.474317
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    An All-Solid-State Flow Cytometer for Counting Fluorescent Microspheres (1995)
    s.l. : American Chemical Society
    Analytical chemistry 67 (1995), S. 2666-2671 
    Details
    ISSN: 1520-6882
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/ac00111a027
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Genetic changes induced in higher plant cells by a laser microbeam (1990)
    Oxford, UK : Blackwell Publishing Ltd
    Physiologia plantarum 79 (1990), S. 0 
    Details
    ISSN: 1399-3054
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: Introducing foreign genes into higher plants has proved to be complicated, with the exception of transformation of protoplasts of some plants (Negrutiu et al. 1987). In particular, culture of protoplasts and regeneration to plants are difficult in many monocotyledonous crops. Therefore, it would be desirable to avoid extensive tissue culture by introducing cloned genes directly into cells. A laser microbeam can perforate plant cell walls, thus facilitating uptake of genes into cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1399-3054.1990.tb05885.x
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Laser in der Reaktionstechnik - Analytik und ManipulationVortrag auf dem Jahrestreffen der Verfahrens-Ingenieure, 25. bis 27. Sept. 1991 in Köln. (1992)
    Weinheim : Wiley-Blackwell
    Chemie Ingenieur Technik - CIT 64 (1992), S. 242-252 
    Details
    ISSN: 0009-286X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Laser in reacton engineering - analysis and manipulation. In recent years several new linear and nonlinear laser spectroscopic techniques have been developed. The high sensitivity of these methods allows the detection of single atoms and molecules as well as non-intrusive measurements of concentrations, temperatures and velocities of reacting species in technical processe with high temporal, spectral and spatial resolution in point as well as in multidimensional measurements. Focussing of UV- and IR-laser radiation into a microscope allows manipulation of biological material by a laser microbeam and an optical tweezer.
    Additional Material: 23 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cite.330640305
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Bildung von Stickstoffoxiden bei der VerbrennungVortrag auf der Dechema-Jahrestagung, 24./25. Juni 1971 in Frankfurt/M. (1972)
    Weinheim : Wiley-Blackwell
    Chemie Ingenieur Technik - CIT 44 (1972), S. 656-659 
    Details
    ISSN: 0009-286X
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Zur Zeit wird in Verbrennungsprozessen insgesamt mehr Luftstickstoff gespalten als auf technischem Wege. Eine quantitative Beschreibung der NO-Bildung bei der Verbrennung mit Hilfe der Geschwindigkeitskonstanten der chemischen Elementarreaktionen zeigt, daß NO im wesentlichen in den heißen Verbrennungsgasen nach Durchgang der Flammenfront entsteht. Zur Verringerung der NO-Menge ist eine Erniedrigung der Sauerstoffatom-Konzentration und der Spitzentemperaturen während der Verbrennung erforderlich. Das kann u. a. durch Mehrstufen-Verbrennung, teilweise Rückführung der Abgase und Zusatz von Wasserdampf erreicht werden. Eine Überführung von NO in N2 nach der Verbrennung ist auf katalytischem Wege durch Zusatz von H2, NH3 und CO möglich.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cite.330441004
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Reaktionen von Atomen (1971)
    Weinheim : Wiley-Blackwell
    Zeitschrift für die chemische Industrie 83 (1971), S. 561-577 
    Details
    ISSN: 0044-8249
    Keywords: Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: In den letzten Jahren sind mehrere Methoden entwickelt worden, die eine quantitative Untersuchung der Reaktionen freier Atome in der Gasphase ermöglichen. Im vorliegenden Beitrag werden Reaktionen von Wasserstoff-, Kohlenstoff-, Sauerstoff- und Halogenatomen mit einfachen Molekülen besprochen. Die Ergebnisse solcher Untersuchungen sind für das Verständnis chemischer Umsetzungen und für viele technische Anwendungen - wie Explosions- und Verbrennungsprozesse, Halogenierungen, chemische Laser - von grundsätzlicher Bedeutung.
    Additional Material: 20 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ange.19710831503
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Laser in der Chemie - wo stehen wir heute? (1987)
    Weinheim : Wiley-Blackwell
    Zeitschrift für die chemische Industrie 99 (1987), S. 38-58 
    Details
    ISSN: 0044-8249
    Keywords: Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: In den letzten Jahren sind verschiedene Methoden entwickelt worden, um den Ablauf chemischer Reaktionen mit Hilfe von Laserstrahlung zu beobachten und gezielt zu beeinflussen. Durch Steuerung der relativen Geschwindigkeit und Orientierung der Reaktionspartner sowie durch Rotations- und Schwingungsanregung mit abstimmbaren Infrarot- oder UV-Lasern können Einblicke in die mikroskopischen Abläufe bei der Öffnung und Neuknüpfung chemischer Bindungen erhalten werden. Als Beispiele für den Einsatz des Lasers in der Synthese werden die Erzeugung von Monomeren wie Vinylchlorid und Polymeren wie Polyethylen sowie von biologisch aktiven Substanzen wie Vitamin-D3 besprochen. Darüber hinaus werden die Trennung von Isotopen, Entfernung von Verunreinigungen, Herstellung von Katalysatoren, Gläsern und Keramiken sowie Oberflächenbehandlungen durch Abscheidung oder Abtragung von Material mit Hilfe von Lasern vorgestellt. Abschließend wird auf Anwendungen des Lasers in der Medizin eingegangen.
    Additional Material: 35 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ange.19870990107
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Reactions of Atoms (1971)
    Weinheim : Wiley-Blackwell
    Angewandte Chemie International Edition in English 10 (1971), S. 604-619 
    Details
    ISSN: 0570-0833
    Keywords: Atoms ; Gas-phase reactions ; Carbon ; Halogens ; Hydrogen ; Oxygen ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Several methods for the quantitative investigation of reactions of free atoms in the gas phase have been developed in recent years. The present article deals with reactions of hydrogen, carbon, oxygen, and halogen atoms with simple molecules. The results of such investigations are of fundamental importance for the understanding of chemical reactions and for many technical applications, such as explosion and combustion processes, halogenations, and chemical lasers.
    Additional Material: 20 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/anie.197106041
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Laser Chemistry-What is Its Current Status? (1987)
    Weinheim : Wiley-Blackwell
    Angewandte Chemie International Edition in English 26 (1987), S. 38-58 
    Details
    ISSN: 0570-0833
    Keywords: Laser chemistry ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: In recent years, various methods have been developed to observe and to influence the course of chemical reactions using laser radiation. By selectively increasing the translational, rotational, and vibrational energies and by controlling the relative orientation of the reaction partners with tunable infrared and UV lasers, direct insight can be gained into the molecular course of the breaking and re-forming of chemical bonds. Examples for the application of lasers include the synthesis of monomers such as vinyl chloride and polymers such as polyethylene, the synthesis of biologically active substances such as vitamin D3, the separation of isotopes, the removal of impurities, the production of catalysts, glasses, and ceramics, and the deposition and ablation of material on surfaces. Finally, several applications of lasers in medicine are discussed.
    Additional Material: 35 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/anie.198700381
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...