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61.
H. Fischer U. Gonser R. Preston H.-G. Wagner 《Journal of magnetism and magnetic materials》1978,9(4):336-338
In a ribbon of amorphous Fe40Ni40P14B6 (Metglas 2826) the iron spins tend to be parallel to the plane of the ribbon, but the distribution of spin directions within the plane is nearly random. When a uniaxial tensile stress is applied to the ribbon the spins become almost completely aligned parallel to the applied stress. The technique of Mössbauer polarimetry was used to detect and measure this effect. 相似文献
62.
The spectra of certain deuteriated binuclear chromium complexes have been obtained which help to elucidate some of the fragmentation processes of the molecular ion. The effect of the relative strengths of the metal-ligand and metal nitrosyl bonds is also discussed. 相似文献
63.
I.Ralph C. Bick Mohammad A. Hai Nigel W. Preston Rex T. Gallagher 《Tetrahedron letters》1980,21(6):545-546
Aristotelinone and serratoline, two new Aristotelia alkaloids, are shown to have indole and indolenine structures respectively from their spectra and reduction products. 相似文献
64.
We analyze the renormalized strong coupling series for lattice g0φ4 field theory which is a double series in x = M4a4/g0a4?dandy = 1/M2a2, where M is the renormalized mass, a the lattice spacing, g0 the bare coupling constant and d the dimension of space-time. We extrapolate to large y for fixed x by using a Padé-like extrapolation technique. We study the dimensionless renormalized coupling constant G/M4?d and find that as we approach the continuum(x → 0, y → ∞) the entire spectrum of g0 from zero to infinity can be studied. Our results for d = 1,2,3,4 based on a series in y up to y5 and in x up to x3 show that for fixed lattice spacing a, G/M4?d is a monotonic function of g0 ranging from zero at g0 = 0 to a maximum at g0 = ∞. Using the high temperature expansion results, we have also derived 9 terms in y on 8 lattices of dimension 1,2,3 and 4 for the linear term in x, and studied this series to see if one can see a breakdown in this monotonic behavior of G for large y. The analysis of this latter series is inconclusive. 相似文献
65.
Cui J Hamilton MF Wilson PS Zabolotskaya EA 《The Journal of the Acoustical Society of America》2006,119(4):2067-2072
The dynamic response of an acoustically driven spherical bubble between parallel plates is investigated in the linear approximation. For the case of rigid plates, explicit expressions are provided for the resonance frequency and damping, and the importance of including compressibility of the liquid is discussed. For wide channels, approximate results are presented that account for finite acoustic impedance of the plates. 相似文献
66.
[Structure: see text] A new mechanism involving a diimine intermediate is proposed for vicinal diamine-catalyzed synthesis of warfarin. Decreasing the NCCN dihedral angle by varying the diamine results in an increase in the enantioselectivity of warfarin synthesis. 相似文献
67.
[Structure: see text] The structural consequences of coordinating 2,6-bis[2-((4S)-4-methyl-4,5-dihydro-1,3-oxazol-2-yl)phenyl]carbamoylpyridines, 2, with divalent metals such as Cu(II), Ni(II), and Zn(II) are reported. Metal coordination occurs under mild conditions in a manner that preserves the helical bias of the parent ligand in the solid state and in solution. 1H NMR line-shape analysis indicates that metal coordination increases the helical interconversion barrier, thus rigidifying the dynamic helicity of 2. 相似文献
68.
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70.
A prototype generator for creating a continuous stream of explosive vapor was referenced quantitatively both to a standard weight from the National Institute of Standards and Technology (NIST) and to the response of an ion mobility spectrometer. Vapors from solid explosive, in a precision bore glass tube at constant temperature, diffuse into an inert gas flow. Mass output rates were determined by (1) sample temperature, and (2) sample tube dimensions (length and cross-sectional area). A reference to NIST was achieved gravimetrically though a microbalance calibrated with a reference weight; mass output rates were obtained for 2,4,6-trinitrotoluene (TNT), cyclotrimethylenetrinitramine (RDX) and pentaerythritol tetranitrate (PETN) at three or more oven temperatures between 79 degrees C and 150 degrees C. The mass output rate was stable over hundreds of hours of continuous operation and the output was adjustable from a few picograms per second to several nanograms per second through variation of the oven temperature. An independent calibration of the vapor generator for TNT at 79 degrees C using an ion mobility spectrometer matched exactly the gravimetric-based findings. In most instances, measured mass output rates compared favorably with theoretically calculated mass output rates, with discrepancies in a few cases resulting primarily from uncertainties in terms (vapor pressures and diffusion coefficients) used to perform the calculations. Agreement is generally not good for PETN, where molecular decomposition contributed to higher than expected measured mass outputs. 相似文献