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131.
Béatrice Rivière Simon Shaw J.R. Whiteman 《Numerical Methods for Partial Differential Equations》2007,23(5):1149-1166
We consider the usual linear elastodynamics equations augmented with evolution equations for viscoelastic internal stresses. A fully discrete approximation is defined, based on a spatially symmetric or non‐symmetric interior penalty discontinuous Galerkin finite element method, and a displacement‐velocity centred difference time discretisation. An a priori error estimate is given but only the main ideas in the proof of the error estimate are reported here due to the large number of (mostly technical) estimates that are required. The full details are referenced to a technical report. © 2007 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2007 相似文献
132.
David N. Thompson Peter G. Shaw Jeffrey A. Lacey 《Applied biochemistry and biotechnology》2003,105(1-3):205-218
Silica and alkali metals in wheat straw limit its use for bioenergy and gasification. Slag deposits occur via the eutectic
melting of SiO2 with K2O, trapping chlorides at surfaces and causing corrosion. A minimum melting point of 950°C is desirable, corresponding to an
SiO2:K2O weight ratio of about 3:1. Mild chemical treatments were used to reduce Si, K, and Cl, while varying temperature, concentration,
% solids, and time. Dilute acid was more effective at removing K and Cl, while dilute alkali was more effective for Si. Reduction
of minerals in this manner may prove economical for increasing utilization of the straw for combustion or gasification. 相似文献
133.
134.
We show that in $\operatorname{PG}(4,2)$ there exist octets $\mathcal{P}
_{8}=\{\pi_{1},\,\ldots\,,\pi_{8}\}$ of planes such that the 28
intersections $\pi_{i}\cap\pi_{j}$ are distinct points. Such
conclaves (see [6]) $\mathcal{P}_{8}$ of planes
in $\operatorname{PG}(4,2)$ are shown to be in bijective correspondence
with those planes $P$ in $\operatorname{PG}(9,2)$ which are external to
the Grassmannian $\mathcal{G}_{1,4,2}$ and which belong to the orbit
$\operatorname{orb}(2\gamma)$ (see [4]). The fact
that, under the action of $\operatorname{GL}(5,2),$ the stabilizer
groups $\mathcal{G}_{\mathcal{P}_{8}}$ and $\mathcal{G}_{P}$ both have
the structure $2^{3}:(7:3)$ is thus illuminated. Starting out from a
regulus-free partial spread $\mathcal{S}_{8}$ in
$\operatorname{PG}(4,2)$ we also give a construction of a conclave of
planes $P\in\operatorname{orb}(2\gamma)\subset\operatorname{PG}(9,2).$ 相似文献
135.
136.
The rotational structure of the ν2 band of D216O between 700 and 1550 cm?1 has been analyzed from spectra recorded with a Fourier transform spectrometer (nominal resolution: 0.1 cm?1). By applying Watson's reduced Hamiltonian and a least squares method to the set of observed transitions, together with microwave data and the infrared data of Williamson, 22 rotational constants for the ground state and 17 for the upper state have been obtained which predict the positions of more than 700 observed lines with a standard deviation of 0.04 cm?1. 相似文献
137.
138.
139.
The fine structures of the (ν1 + ν2) and (ν2 + ν3) combination bands of ozone in the 5.7-μm region have been recorded and analyzed. The two vibrational states are coupled through Coriolis and second-order distortion terms. The interaction has been treated by the numerical diagonalization of the secular determinant for the two coupled states. With the centrifugal distortion parameters fixed to the ground state values, the following constants have been obtained: ν1 + ν2 = 1796.266, A110 = 3.6104, B110 = 0.44145, , ν2 + ν3 = 1726.526, A011 = 3.5537, B011 = 0.43982, , Y13 = ?0.466, and X13 = ?0.010 cm?1. In addition, the following anharmonic constants have been obtained: x12 = ?7.821 and x23 = ?16.494 cm?1. The value of the dipole moment ratio, , is 1.30 ± 0.10. 相似文献
140.
J Zwislocki B Kruger J D Miller A F Niemoeller E A Shaw G Studebaker 《The Journal of the Acoustical Society of America》1988,83(4):1688-1689
The advantages and disadvantages of three types of earphones for audiometric testing are discussed. Supraaural earphones continue to be recommended for this purpose, in preference to circumaural and insert types. 相似文献