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41.
R.H. Howell D.L. Matthews 《Journal of Quantitative Spectroscopy & Radiative Transfer》1980,23(5):513-515
A method for obtaining values of the widths and other parameters describing the Gaussian and Lorentzian components of peaks, which have the shape of the convolution of those functions, is described. Results of the method are given for X-ray data containing several peaks with different ratios of the composite widths in separate spectra. 相似文献
42.
The dependence of tensor rank on the underlying ring of scalars is considered. It is shown that the integers are, in a certain sense, the worst scalars. A ring of scalars can be improved by adjoining algebraic elements but not by adjoining indeterminates. The real closed fields are the best scalars among ordered rings, and the algebraically closed fields are best among all rings. Let B(Rm×n×p) be the maximum tensor rank of any m×n×p array of elements from the ring R. A generalization of Gaussian elimination shows that B(Rn×n×n)?n2 for most useful rings R. For every R, B(Rm×n×p)?mnp/(m+n+p), and slightly stronger lower bounds are proven for R a field. 相似文献
43.
Xu W Dutta D Xiong F Anderson B Auberbach L Averett T Bertozzi W Black T Calarco J Cardman L Cates GD Chai ZW Chen JP Choi S Chudakov E Churchwell S Corrado GS Crawford C Dale D Deur A Djawotho P Filippone BW Finn JM Gao H Gilman R Glamazdin AV Glashausser C Glöckle W Golak J Gomez J Gorbenko VG Hansen JO Hersman FW Higinbotham DW Holmes R Howell CR Hughes E Humensky B Incerti S de Jager CW Jensen JS Jiang X Jones CE Jones M Kahl R Kamada H Kievsky A Kominis I Korsch W Kramer K Kumbartzki G 《Physical review letters》2000,85(14):2900-2904
We have measured the transverse asymmetry A(T') in 3He(e,e(')) quasielastic scattering in Hall A at Jefferson Laboratory with high precision for Q2 values from 0.1 to 0.6 (GeV/c)(2). The neutron magnetic form factor G(n)(M) was extracted based on Faddeev calculations for Q2 = 0.1 and 0.2 (GeV/c)(2) with an experimental uncertainty of less than 2%. 相似文献
44.
N. Howell Furman W. Le Roy Mc Cay A. Kling A. Lassieur F. Ibbotson L. Aitchison C. S. Marvel und O. Kamm 《Fresenius' Journal of Analytical Chemistry》1924,65(3-4):153-155
Ohne Zusammenfassung 相似文献
45.
Overtone spectrum of o, m and p-nitrobenzaldehydes and p-chlorobenzaldehyde has been studied in 2000–12000 cm−1 region. Vibrational frequencies and anharmonicity constants for aryl as well as alkyl CH stretch vibrations have been determined.
We have also determined the internuclear distances for the aryl CH bond in the different molecules. The small variation observed
in these distances is an indication of the substitution effect.
It is observed that in the case of p-disubstituted benzens, the shift in aryl CH bond is proportional to sum of the Hammet σ of the substituents. However in the
case of o-disubstituted benzenes it is only 80% of the para-substituted shift. 相似文献
46.
Andrew D. Burnett Dr. John Kendrick Dr. John E. Cunningham Dr. Michael D. Hargreaves Dr. Tasmin Munshi Dr. Howell G. M. Edwards Prof. Edmund H. Linfield Prof. A. Giles Davies Prof. 《Chemphyschem》2010,11(2):368-378
The terahertz frequency spectrum of pentaerythritol tetranitrate (PETN) is calculated using Discover 1 with the COMPASS 2 force field, CASTEP[3] and PWscf. 4 The calculations are compared to each other and to terahertz spectra (0.3–3 THz) of crystalline PETN recorded at 4 K. A number of analysis methods are used to characterise the calculated normal modes. 相似文献
47.
Karataev P Aryshev A Boogert S Howell D Terunuma N Urakawa J 《Physical review letters》2011,107(17):174801
We represent the first experimental observation of the point spread function (PSF) of optical transition radiation (OTR) performed at KEK-Accelerator Test Facility extraction line. We have demonstrated that the PSF vertical polarization component has a central minimum with a two lobe distribution. However, the distribution width varied significantly with wavelength. We assume that we observed a severe effect from spherical or chromatic aberrations which are not taken into account in any existing theoretical model. We believe that the result of this work will encourage theoreticians to continue developing the theory as it is important for various transition radiation applications. Nonuniform distribution of the OTR PSF creates an opportunity for developing a submicrometer transverse beam size monitor. 相似文献
48.
The thermal degradation of a series of 1,1,2,2-tetraaryl-1,2-ethanediols has been examined using thermogravimetry (TG) and
gas chromatography/mass spectrometry (GC/MS). These compounds are smoothly converted to the corresponding diaryl ketone and
diaryl carbinol, i.e., the compounds undergo disproportionation arising from homolytic cleavage of the central carbon–carbon
bond. Presumably, cleavage of the carbon–carbon bond generates a radical pair which disproportionates to provide the observed
products. 相似文献
49.
50.
Jerald K. Rasmussen Steven M. Heilmann Larry R. Krepski Howell K. Smith Alan R. Katritzky Kumars Sakizadeh 《Journal of polymer science. Part A, Polymer chemistry》1986,24(11):2739-2747
The reaction of bisazlactones (2-oxazolin-5-ones) with primary diamines containing additional secondary or tertiary amine functionality (e.g., diethylenetriamine, triethylenetetramine, or N-methyliminobispropylamine) readily produces polyamides which serve as precursors to a new class of heterocyclic polymers. Thermal cyclodehydration takes place under relatively mild conditions (180–200°C) to produce water-soluble polymers containing the 2-imidazolin-5-one heterocycle. Model reactions have been studied to verify this mode of cyclization and confirm the proposed polymer structure. 相似文献