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  • 1
    Electronic Resource
    Electronic Resource
    Radiative lifetimes and reactivity of metastable NO+(a 3Σ+,v) and O+2(a 4Πu,v) (1991)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 95 (1991), S. 2259-2264 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The radiative lifetimes and reactivity of metastable NO+(a 3Σ+) and O+2(a 4Πu) have been investigated using a triple cell ion cyclotron resonance (ICR) spectrometer. Radiative lifetimes of (100±20) ms and (135±25) ms have been found for NO+(a 3Σ+) v≥1 and v≥0 respectively, with Ar and CO2 as monitor gases. The overall reaction rate of NO+(a 3Σ+,v≥1) with Ar (6.5×10−10 cm3 s−1 ) is 1 order of magnitude larger than the rate of v=0 determined in flowing afterglows. CO2 reacts at collision rate. For O+2 the overall lifetime of v≥0, determined with Ar as monitor, is (30±6) ms in between the two values (7 and 130 ms) found by Bustamente et al. using the photodissociation technique. The possible reasons for the longer lifetimes determined in previous ICR experiments is discussed. In the absence of any ab initio calculation, the experimental results on NO+(a 3Σ+) may only be compared to values calculated using an approximated perturbation model. Unfortunately, the reliability of this model, also used in the previous studies, is very limited because of the large uncertainty on the coupling between the metastable a 3Σ+ and the perturbing radiative A 1Π states.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.460982
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  • 2
    Electronic Resource
    Electronic Resource
    Synthesis of 4,6-anhydro-α-d-galactopyranosyl-6-O-mycoloyl- and -corynomycoloyl-α-d-galactopyranoside
    Amsterdam : Elsevier
    Carbohydrate Research 155 (1986), S. 223-228 
    Details
    ISSN: 0008-6215
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://linkinghub.elsevier.com/retrieve/pii/S0008-6215(00)90150-2
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  • 3
    Electronic Resource
    Electronic Resource
    Synthesis and properties of high-Tc YBa2Cu3O7−y oriented thin films (1990)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 68 (1990), S. 3493-3497 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The a- and c-axis-oriented YBa2Cu3O7−y thin films were prepared by rf magnetron sputtering technique. The characterization of the thin films was carried out by inductively coupled plasma atomic emission spectroscopy, x-ray diffraction, and scanning Auger profile techniques. The Tc, Tc(H), Jc(H), and Hc2 -T(near Tc) were measured by the standard dc four-probe method. It was found that very strong anisotropy of this material was manifested in its superconducting properties, especially for c-axis-oriented thin films. It was also found that Jc depends very strongly upon stoichiometric composition 123, preferential orientation of the film, and the characteristic of the film-substrate interface.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.346360
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  • 4
    Electronic Resource
    Electronic Resource
    Giant magneto-optical Kerr effect enhancement in layered CoMn/Si structures (2000)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 87 (2000), S. 6788-6790 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: For sputtered Co57Mn43/Si film samples with different ferromagnetic thickness, the spectra of the complex magneto-optical polar Kerr rotation and optical constants were ex-situ measured. For 5 nm-thick Co57Mn43 film, the Kerr rotation around 4.3 eV was enhanced by a factor of about 10 times with lower loss of the signal intensity as compared to the thick film. Numerical calculations show that the enhancement effect is attributed to an interplay between optical properties of Co57Mn43 and substrate Si that has a strong interband transition (E2) near 4.3 eV. © 2000 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.372842
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  • 5
    Electronic Resource
    Electronic Resource
    Characterization of YBa2Cu3O7−x bulk samples prepared by citrate synthesis and solid-state reaction (1989)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 66 (1989), S. 312-315 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: YBa2Cu3O7−x bulk samples made by citrate synthesis and pyrolysis are characterized and compared with samples made by solid-state reaction. Calcination at 830 °C followed by sintering at 950 °C of samples made of pyrolyzed powder gives pellets with quite good superconducting properties. They are very dense (6.06 g/cm3) and have a specific heat jump of 4 J/mol K at 91 K. X-ray diffraction shows a strong c-axis orientation, scanning electron microscope, and energy dispersive x-ray spectroscopy show a homogeneous structure and composition for these kinds of samples.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.343875
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  • 6
    Electronic Resource
    Electronic Resource
    Plant regeneration from protoplasts of durum wheat (Triticum durum Desf. cv. D6962) (1993)
    Springer
    Plant cell reports 12 (1993), S. 320-323 
    Details
    ISSN: 1432-203X
    Keywords: embryogenesis ; liquid callus cultures ; plant regeneration ; protoplast ; suspension cultures ; Triticum durum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Suspension cultures of durum wheat were established from embryogenic callus maintained in liquid medium for 30 months. Protoplasts were readily isolated from the suspension cultures with yields as high as 3 X 107 protoplasts per g fresh weight suspension cells. When incubated in a modified MS medium containing half strength of the macroelements, 5 μM 2,4-D (2,4-dichlorophenoxyacetic acid) and 0.6 M glucose, protoplast-derived cells divided at frequencies ranging from 1.4 to 10.0 %. After transfer to a solid subculture medium, the protoplast-derived colonies formed embryogenic protuberances, from which green plants have been regenerated.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00237427
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  • 7
    Electronic Resource
    Electronic Resource
    Plant regeneration from protoplasts of wheat (Triticum aestivum cv. Hartog) (1992)
    Springer
    Plant cell reports 11 (1992), S. 16-19 
    Details
    ISSN: 1432-203X
    Keywords: Embryogenesis ; Plant regeneration ; Protoplast ; Suspension cultures ; Wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Morphologically normal green plants have reproducibly been regenerated from protoplasts of an Australian wheat (Triticum aestivum cv. Hartog). The protoplasts were isolated from fine embryogenic suspension cultures which were initiated from embryogenic callus. Protoplasts were incubated in a modified liquid MS medium containing half strength of the macroelements, 5 μm 2,4-D and 0.6 M glucose. Colonies were formed at frequencies ranging from 0.1% to 5%. The frequency of colonies forming fully developed plants varied between 1% and 25%. More than eighty green plants with morphologically normal shoots and roots have been obtained and there was no difficulty in establishing these plants in soil. A cytological study of several randomly selected regenerated plants showed the normal chromosome complement for wheat (2n = 42).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00231832
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  • 8
    Electronic Resource
    Electronic Resource
    Transformation of wheat (Triticum aestivum L.) through electroporation of protoplasts (1994)
    Springer
    Plant cell reports 14 (1994), S. 192-196 
    Details
    ISSN: 1432-203X
    Keywords: gene transfer ; selection for phosphinothricin resistance ; transgenic plants
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Protoplasts isolated from embryogenic suspension cultures of wheat (Triticum aestivum cv. Hartog) were electroporated in the presence of plasmid pEmuGN and/or pEmuPAT, which contained the reporter gene gus and selectable marker gene bar, respectively. Under optimised electroporation conditions, up to 0.9% of viable protoplasts displayed gus activity two days after electroporation. To select for phosphinothricin (PPT) resistant colonies, electroporated protoplasts were incubated for six weeks in a medium containing 10 μg/ml PPT. The cells surviving the selection were maintained as individual colonies on solid medium or as suspension cultures. More than 60% of these colonies exhibited tolerance to 40 μg/ml PPT when tested 10 months after initial selection. To date, 57 green plants have been regenerated from these colonies and 24 have been transferred to soil. Southern blot analyses of colonies and plants, using the bar gene sequence as the probe, confirmed transformation of the cells. Positive PAT assays of both regenerated colonies and plants indicated the presence of the bar gene product. These results provide a basis for the establishment of routine procedures for transformation of wheat by direct gene transfer into protoplasts.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00233789
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  • 9
    Electronic Resource
    Electronic Resource
    Cell aggregates in wheat suspension cultures and their effects on isolation and culture of protoplasts (1994)
    Springer
    Plant cell reports 13 (1994), S. 176-179 
    Details
    ISSN: 1432-203X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Fine embryogenic suspension cultures of wheat (Triticum aestivum cv Hartog and Timmo, and T. durum cv D6962) tend to grow into large cell clumps (1–3 mm), resulting in the formation of mixed suspension cultures consisting of both fine and large cell clumps. The cell clumps were separated according to their sizes and cultured as new lines to investigate their growth rate and differentiation potential and the effects of cell aggregate size on protoplast culture. The results showed that the fine clusters (〈310 μm) had a higher growth rate but a lower differentiation frequency than the large cell aggregates (310–2000 μm). After 2–4 weeks incubation, all the new lines reformed mixed suspension cultures again. The large clumps (〉1100 μm) released fine cell clusters into the medium so it was possible to initiate fine embryogenic suspension cultures from the large clumps. With regard to the isolation and culture of protoplasts, although the highest yield of protoplasts was obtained from the fine cell clusters, the protoplasts isolated from different sized cell aggregates all had similar potential for sustained cell division and plant regeneration.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00239887
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  • 10
    Electronic Resource
    Electronic Resource
    Laser welding of oxide dispersion-strengthened alloy MA754 (1992)
    Springer
    Journal of materials science 27 (1992), S. 2687-2694 
    Details
    ISSN: 1573-4803
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Conventional arc-welding of MA 754, an oxide dispersion-strengthened (ODS) superalloy, poses two significant problems: agglomeration of dispersoids and weld solidification grain boundaries perpendicular to the rolled direction, both of which reduce the high-temperature creep and stress rupture properties. In the present work, laser welding of MA 754 alloy was conducted to determine the effects of a high energy density source on the microstructure and mechanical properties of a 3.2 mm thick butt joint. Tungsten-inert-gas (TIG) welding was also studied for comparison purpose. X-ray diffraction, optical microscopy and scanning electron microscopy analysis coupled with tensile, hardness and hot corrosion tests were used to evaluate the performance of weldments. Results indicated the absence of dispersoid agglomeration and superior tensile and corrosion properties of laser weldments over arc welds. The properties of laser weldments are comparable to those of wrought MA 754.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00540691
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