Library

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
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The microstructure of Mo-sheathed Chevrel-phase superconducting wires was investigated by high-resolution scanning electron microscopy (SEM). Excess Pb forms small nodules (10–30 nm) on the Chevrel-phase grains or wetting layers between the Chevrel grains. The critical current density Jc is strongly reduced when wetting layers are present. However, second-phase Mo exists as islands as large as 2–10 μm and has little harmful effect on Jc. Although some Mo-sheathed wires sintered at 700 °C show relatively high Jc ( ≥ 2 × 108 A/m2 at 8 T), the Chevrel phase in these wires has a very porous microstructure, and the Jc values measured with a magnetic field parallel to the current, Jc((parallel)), were only about 10% higher than the Jc values measured with a field perpendicular to the current, Jc(⊥). This clearly suggests that the transport current flows percolatively in these wires. Much denser microstructures were obtained by hot-isostatic-pressing (HIP) treatments at 1200 °C, and very high Jc values, (approximately-greater-than) 5 × 108 A/m2 at 8 T and 9.3 × 107 A/m2 at 23 T, which are of the order of the highest Jc values so far reported, were observed. High-resolution SEM observations of HIP'ed wires demonstrate that the interconnectivity between the Chevrel grains was much improved.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 96 (1992), S. 3824-3829 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: We have studied the dimerization equilibrium of 2-methyl-2-nitrosopropane (MNP) at 60 and 35 °C in argon and xenon up to densities about twice the critical density of the solvent. With an increase in the solvent density, the dimerization equilibrium constant at 60 °C decreases in the low-density region, whereas it increases in the high-density region. The inversion of the density dependence occurs around ρr(approximately-equal-to)0.8 in argon and ∼1.4 in xenon, where ρr means the density reduced by the critical density of the solvent fluid. The equilibrium constant in xenon at 35 °C increases with increasing solvent density in the low-density region (ρr〈∼0.5), while it decreases in the medium-density region (0.5〈ρr〈1.5). The equilibrium constant in argon at 35 °C has a similar density dependence to that at 60 °C. The internal energy change for the dimerization shows a large density dependence in the low-density region of xenon, while it changes little with density in argon. The theoretical calculation by the Percus–Yevick (PY) approximation for a simple reaction model gives a poor result for the density dependence of the equilibrium constant, although the temperature dependence of the equilibrium constant is reproduced qualitatively. The calculation for a more realistic model including the molecular anisotropy of MNP suggests that the density dependence at the low-density limit is sensitive to the interaction model.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: We have studied the dimerization equilibrium of 2-methyl-2-nitrosopropane in carbon dioxide (CO2), chlorotrifluoromethane (CClF3), and trifluoromethane (CHF3) at 60 °C from the gaseous to liquid states. The dimerization equilibrium constants are not monotone functions of the solvent density in all solvent fluids. The density dependence of the equilibrium constant shows two inversions: The equilibrium constants in CO2 and CHF3 increase with increasing solvent density up to ρr(approximately-equal-to)0.3, where ρr is the reduced density by the critical density of solvent, whereas the equilibrium constant in CClF3 shows little dependence on the solvent density in this density region. From ρr(approximately-equal-to)0.3 to about 1.4, the equilibrium constants decrease with increasing solvent density. In the higher-density region, the equilibrium constants increase again. We measured the equilibrium constants in CClF3 and CHF3 at 35 °C, and obtain the density dependence of the equilibrium constant which is almost the same as that at 60 °C. The effects of the temperature and the solvent species on the equilibrium constant are larger in the low-density region than in the high-density region. The differences between the low- and high-density regions suggest that the energetic factor is dominant in the low-density region, and that the packing effect is dominant in the high-density region. The experimental results are qualitatively reproduced by a simple reaction model where two spherical molecules dimerize in a fluid composed of spherical molecules, although the reaction model overestimates the equilibrium constant.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 98 (1993), S. 5996-5998 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: We have performed the first direct pump-probe transient-absorption measurements on the near-infrared (IR) band of the equilibrated aqueous solvated electron. The pump pulse was centered at 780 nm. The absorption spectrum of the excited state is observed to be red-shifted relative to the ground-state absorption. The radiationless transition from the excited state to the ground state occurs with an average time constant of 550±170 fs. In observing a subpicosecond lifetime and red-shifted absorption for the excited p-states, these experiments are in accord with a growing body of experimental and theoretical work, serving to provide a consistent picture of the photophysics of the solvated electron.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 80 (1996), S. 1678-1681 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The electron spin resonance studies have been carried out in the temperature range 130–300 K on semiconducting β-FeSi2 single crystals grown by a chemical vapor transport technique. Two anisotropic doublets with apparent g factors in the range 2.025–2.05 and 1.98–2.03, as well as one complex signal having an isotropic g factor of 2.0195 and exhibiting a five-line hyperfine structure, have been detected. The doublet signals are believed to arise from spin triplet (S=1) states of, presumably, substitutional Ni2+ transition ions, whereas the signal exhibiting the hyperfine structure has been attributed to the spin of a hole, captured by silicon vacancy and interacting with nuclear spins of four iron atoms in the first shell surrounding of the silicon vacancy. © 1996 American Institute of Physics.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 58 (1991), S. 298-300 
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Using molecular beam epitaxy, we have successfully prepared PrBa2Cu3Oy (PBCO) films and PBCO/YBa2Cu3Oy (YBCO) layered structures. Epitaxial growth of these films was confirmed by in situ reflection high-energy electron diffraction. The temperature dependence of resistivity in the PBCO film showed semiconducting behavior. The lattice parameters of Pr1+xBa2−xCu3Oy films decreased when x increased and almost coincided with that of well-oxidized YBa2Cu3Oy films (y∼7) when x∼0.3. These experimental results indicate that YBCO/PBCO/YBCO multilayers are suitable for artificial layered structures of oxide superconductors, i.e., electronic devices.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    The @journal of physical chemistry 〈Washington, DC〉 98 (1994), S. 3450-3458 
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 105 (1996), S. 10084-10091 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The structures and the thermodynamic properties of a fluid composed of a nonpolar or a polar dumbbell molecule have been studied from the gaslike to the liquidlike density regions based on two types of the reference interaction site model (RISM) integral equation theories (RISM-1 and RISM-2). This is the first application of the RISM-2 theory to a polar dumbbell fluid. We have proven that the RISM-2 theory with the hypernetted-chain (HNC) approximation has an inconsistency with respect to the zeroth-order relation between site–site total correlation functions and site–site direct correlation functions in the Fourier space. An hypothetical bridge function is introduced to remedy this inconsistency, which works well to give good information on the structure and the dielectric constant in the lower-density region. On the other hand, the RISM-1 theory works well in the higher-density region, but not well in the lower-density region. Complemental application of these theories, that is, the RISM-1 theory for the high-density region and the RISM-2 theory for the low-density region, allows us to understand the properties of fluid over wide density regions. © 1996 American Institute of Physics.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 113 (2000), S. 4340-4348 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: We have measured the vibrational energy relaxation of azulene in the S2 state in ethane, carbon dioxide, and xenon over a wide density region by the time-resolved fluorescence spectroscopy. The reduced density of the solvent (the density divided by the critical density) has been changed from the gaslike one (lower than 0.05) to the liquidlike one (2.8 for ethane, 2.7 for carbon dioxide, and 2.0 for xenon). The density dependence of the relaxation rate is compared with that of azulene in the S0 state [D. Schwarzer, J. Troe, M. Votsmeier, and M. Zerezke, J. Chem. Phys. 105, 3121 (1996)]. Although the absolute rate largely depends on the electronic state, the density dependence of the relaxation rates is roughly the same for both electronic states, which can be considered as a side-proof of the isolated binary collision model. Possible origins for the validity of the isolated binary collision model are discussed. © 2000 American Institute of Physics.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Dental traumatology 14 (1998), S. 0 
    ISSN: 1600-0595
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Abstract— The purposes of the study were to observe the morphological changes on root canal walls after instrumentation and irrigation, and assess the efficacy of conventional cleansing procedures and the effectiveness of Er:YAG laser in removing debris and smear layer from the root canal walls. Thirty-six endodontically treated human mandibular incisor teeth with single root canals were bisected longitudinally and divided into three groups of 12 teeth. Group 1 (Gl) was left unlased as a control. The teeth of group 2 (G2) and group 3 (G3) were irradiated by Er:YAG laser (laser parameters were set at 1 W, 100 mJ/pulse and 10 Hz) for 3 s and 5 s. The teeth were prepared for scanning electron microscope study. Control specimens showed debris and heavy smear layer obscuring the dentinal tubules at all levels in the canals. The root canal walls irradiated by Er:YAG laser were free of debris, with an evaporated smear layer and open dentinal tubules. These results suggested that Er:YAG laser irradiation had an efficient cleaning effect on the prepared root canal walls.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...