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  • 1
    Electronic Resource
    Electronic Resource
    Plasma generation in an organic molecular gas by an ultraviolet laser pulse (1993)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 73 (1993), S. 4779-4784 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Plasmas are generated in a low ionization potential gas, tetrakis(dimethylamino)ethylene (TMAE) vapor through a one-photon ionization process by an ultraviolet laser beam at a 193 nm wavelength. The TMAE plasma characteristics are studied by means of a Langmuir probe and microwave scattering. A new method is used to measure the 193 nm ultraviolet (UV) photon absorption cross section in TMAE. It is determined to be 1.1±0.3×10−17 cm2 from the axial profile of electron density. The temporal evolution of electron temperature is measured. A peak electron density of ne=5×1013/cm3 and peak electron temperature of Te=1 eV are measured at 500 mTorr TMAE pressure. The plasma decay process is studied, and the electron-ion recombination coefficient is measured to be 5.4±0.5×10−6 cm3/s. A theoretical model is derived to describe the photon flux and the one photon ionization process. An application of a TMAE plasma as a mirror for microwave reflections is proposed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.353842
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  • 2
    Electronic Resource
    Electronic Resource
    Far-field and beam characteristics of vertical-cavity surface-emitting lasers (1996)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 69 (1996), S. 1829-1831 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We have determined the far-field patterns and beam parameters of vertical-cavity surface-emitting lasers (VCSELs) with different structures. The results show that the window diameter and the active-layer aperture of VCSELs strongly influence laser far-field distributions and beam characteristics; for VCSELs with small window ω=5 μm, only one dominant lobe has been observed in the far-field profiles, even though injected current was increased up to 2 Ith; and the smaller the ratio of the window diameter to the active-layer aperture, the larger is the far-field divergence. The laser structure dependence of the K factor has also been studied. © 1996 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.117447
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  • 3
    Electronic Resource
    Electronic Resource
    Electron cyclotron wave scattering by a probe launched ion acoustic wave (1993)
    New York, NY : American Institute of Physics (AIP)
    Physics of Fluids 5 (1993), S. 3887-3892 
    Details
    ISSN: 1089-7666
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Electromagnetic wave scattering in a plasma half-space from a propagating ion acoustic wave density perturbation with a transverse conducting boundary condition is analyzed. The analysis shows that there are two different types of scattered waves. One propagates only in the region where the plasma density is perturbed, its frequency and wave vector satisfies the conditions for a three-wave interaction process. The other propagates as an unperturbed electron cyclotron mode with either an upshifted or downshifted frequency. Experiments are performed to examine electron cyclotron wave scattering by an ion acoustic wave excited by means of a grid along the magnetic field line in a mirror machine. The backscattered waves propagating away from the density perturbation region are measured and their dependence on the ion acoustic wavelength is examined. The scattered wave in the region of ion acoustic wave propagation is examined by measuring the scattered wave field pattern when the ion acoustic wave number is much larger than that of the incident wave. The measurements demonstrate that the scattered waves indeed propagate as two different modes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.860611
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  • 4
    Electronic Resource
    Electronic Resource
    Bragg scattering of electromagnetic waves by microwave-produced plasma layers (1990)
    New York, NY : American Institute of Physics (AIP)
    Physics of Fluids 2 (1990), S. 667-673 
    Details
    ISSN: 1089-7666
    Source: AIP Digital Archive
    Topics: Physics
    Notes: A set of parallel plasma layers is generated by two intersecting microwave pulses in a chamber containing dry air at a pressure comparable to the upper atmosphere. The dependencies of breakdown conditions on the pressure and pulse length are examined. The results are shown to be consistent with the appearance of tail erosion of the microwave pulse caused by air breakdown. A Bragg scattering experiment, using the plasma layers as a Bragg reflector, is then performed. Both time domain and frequency domain measurements of wave scattering are conducted. The experimental results are found to agree very well with the theory.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.859301
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  • 5
    Electronic Resource
    Electronic Resource
    Propagation of high-power microwave pulses in air breakdown environment (1990)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 67 (1990), S. 2762-2766 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: A chamber experiment is conducted to study the propagation of high-power microwave pulses through the air. Two mechanisms responsible for two different degrees of tail erosion have been identified experimentally. The optimum pulse amplitude for maximum energy transfer through the air has also been determined.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.345442
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  • 6
    Electronic Resource
    Electronic Resource
    A theoretical model for intense microwave pulse propagation in an air breakdown environment (1991)
    New York, NY : American Institute of Physics (AIP)
    Physics of Fluids 3 (1991), S. 2906-2912 
    Details
    ISSN: 1089-7666
    Source: AIP Digital Archive
    Topics: Physics
    Notes: A theoretical model based on two coupled partial differential equations is established to describe the propagation of an intense microwave pulse in air breakdown environment. One is derived from the Poynting theorem, and the other one is the rate equation of electron density. A semiempirical formula of the ionization frequency is adopted for this model. A transformation of these two equations to local time frame of reference is introduced so that they can be solved numerically with considerably reduced computation time. This model is tested by using it to perform the computer simulation of the chamber experiments [S. P. Kuo, Y. S. Zhang, and P. Kossey, J. Appl. Phys. 67, 2762 (1990)]. The numerical results are shown to agree well with the experimental results.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.860001
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  • 7
    Electronic Resource
    Electronic Resource
    Practical aspects of electron holography
    Amsterdam : Elsevier
    Ultramicroscopy 51 (1993), S. 1-14 
    Details
    ISSN: 0304-3991
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Electrical Engineering, Measurement and Control Technology , Natural Sciences in General , Physics
    Type of Medium: Electronic Resource
    URL: http://linkinghub.elsevier.com/retrieve/pii/0304-3991(93)90130-P
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  • 8
    Electronic Resource
    Electronic Resource
    Pion scattering from vibrational nuclei in ^9^0Zr and ^1^1^8Sn
    Amsterdam : Elsevier
    Nuclear Physics, Section A 516 (1990), S. 633-642 
    Details
    ISSN: 0375-9474
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Physics
    Type of Medium: Electronic Resource
    URL: http://linkinghub.elsevier.com/retrieve/pii/0375-9474(90)90131-5
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  • 9
    Electronic Resource
    Electronic Resource
    Cyclic voltammetric studies of pasted nickel hydroxide electrode microencapsulated by cobalt (1998)
    Springer
    Journal of applied electrochemistry 28 (1998), S. 1377-1382 
    Details
    ISSN: 1572-8838
    Keywords: cyclic voltammetry ; microencapsulation ; nickel hydroxide electrode ; oxygen evolution overpotential ; proton diffusion coefficient ; reversibility
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Electrical Engineering, Measurement and Control Technology
    Notes: Abstract Spherical nickel hydroxide microencapsulated by cobalt has been used as the electrochemically active material in pasted-type nickel electrodes of rechargeable alkaline batteries. Cobalt coating on the surface of nickel hydroxide particles can be converted to CoOOH during charge. Well distributed CoOOH forms the conductive network on the surface of nickel hydroxide particles, thereby leading to higher utilization of active material. Cyclic voltammetric studies suggest that nickel hydroxide microencapsulated by cobalt has better reversibility of the Ni(OH)2/NiOOH redox couple, greater discharge capacity and higher oxygen evolution overpotential than nickel hydroxide with added cobalt metal powder as a conductor. The mechanism of the electrode reaction is still found to be controlled by proton diffusion, and the proton diffusion coefficient is 1. 2×10−9cm2s−1.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1003421701762
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  • 10
    Electronic Resource
    Electronic Resource
    Ammonium fixation by clay minerals in different layers of two paddy soils after flooding (1999)
    Springer
    Biology and fertility of soils 29 (1999), S. 152-156 
    Details
    ISSN: 1432-0789
    Keywords: Key words Non-exchangeable ammonium ; Paddy soils ; Redox potential ; Organic substance ; Nitrogen immobilization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract  The influence of flooding and cellulose addition on the fixation of NH4 + in different soil layers of two paddy soils from China (an entisol and an ultisol) was investigated. In both soils the content of total reducing substances (TRS) sharply increased during the first days after flooding and was highest in the anoxic layers. This increase, which was more pronounced in the entisol with the higher total C content, was accompanied by an increase in the concentration of non-exchangeable NH4 + in both soils. The increase in mineralization after flooding, resulting in higher concentrations of exchangeable NH4 +, favoured the fixation of NH4 +. Although the application of cellulose resulted in higher TRS contents, the fixation of NH4 + ions decreased, which may have been the result of microbiological N immobilization.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s003740050538
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