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Characterization of autocatalytic decomposition reactions is important
for the safe handling and storage of energetic materials. Isothermal differential
scanning calorimetry (DSC) has been widely used to detect autocatalytic decomposition
of energetic materials. However, isothermal DSC tests are time consuming and
the choice of experimental temperature is crucial. This paper shows that an
automatic pressure tracking calorimeter (APTAC) can be a reliable and efficient
screening tool for the identification of autocatalytic decomposition behavior
of energetic materials.
Hydroxylamine nitrate (HAN) is an important
member of the hydroxylamine family. High concentrations of HAN are used as
liquid propellants, and low concentrations of HAN are used primarily in the
nuclear industry for decontamination of equipment. Because of its instability
and autocatalytic decomposition behavior, HAN has been involved in several
incidents. 相似文献
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A parallel inexact Newton method with a line search is proposed for two-stage quadratic stochastic programs with recourse. A lattice rule is used for the numerical evaluation of multi-dimensional integrals, and a parallel iterative method is used to solve the quadratic programming subproblems. Although the objective only has a locally Lipschitz gradient, global convergence and local superlinear convergence of the method are established. Furthermore, the method provides an error estimate which does not require much extra computation. The performance of the method is illustrated on a CM5 parallel computer.This work was supported by the Australian Research Council and the numerical experiments were done on the Sydney Regional Centre for Parallel Computing CM5. 相似文献
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The sum of the largest eigenvalues of a symmetric matrix is a nonsmooth convex function of the matrix elements. Max characterizations for this sum are established, giving a concise characterization of the subdifferential in terms of a dual matrix. This leads to a very useful characterization of the generalized gradient of the following convex composite function: the sum of the largest eigenvalues of a smooth symmetric matrix-valued function of a set of real parameters. The dual matrix provides the information required to either verify first-order optimality conditions at a point or to generate a descent direction for the eigenvalue sum from that point, splitting a multiple eigenvalue if necessary. Connections with the classical literature on sums of eigenvalues and eigenvalue perturbation theory are discussed. Sums of the largest eigenvalues in the absolute value sense are also addressed.This paper is dedicated to Phil Wolfe on the occasion of his 65th birthday.The work of this author was supported by the National Science Foundation under grants CCR-8802408 and CCR-9101640.The work of this author was supported in part during a visit to Argonne National Laboratory by the Applied Mathematical Sciences subprogram of the Office of Energy Research of the U.S. Department of Energy under contract W-31-109-Eng-38, and in part during a visit to the Courant Institute by the U.S. Department of Energy under Contract DEFG0288ER25053. 相似文献
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Strongin B Bofill J Friedman JI Fuess S Goodman MC Kendall HW Kistiakowsky V Lyons T Osborne LS Pitt R Schneekloth U Taylor FE Bogert D Koizumi G Stutte L Abolins M Brock R Cobau W Hatcher R Owen D Perkins G Tartaglia M Weerts H Belusevic R Walker JK White A Womersley J 《Physical review D: Particles and fields》1991,43(9):2778-2786
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Several magnetic and optical processes contribute to the magneto-optical response of nickel thin films after excitation by a femtosecond laser pulse. We achieved a first complete identification by explicitly measuring the time-resolved Kerr ellipticity and rotation, as well as its temperature and magnetic field dependence in epitaxially grown (111) and (001) oriented Cu/Ni/Cu wedges. The first hundreds of femtoseconds the response is dominated by state filling effects. The true demagnetization takes approximately 0.5-1 ps. At the longer (sub-ns) time scales the spins are found to precess in their anisotropy field. Simple and transparent models are introduced to substantiate our interpretation. 相似文献
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E. Polak R. S. Womersley H. X. Yin 《Journal of Optimization Theory and Applications》2008,138(2):311-328
We present a new active-set strategy which can be used in conjunction with exponential (entropic) smoothing for solving large-scale
minimax problems arising from the discretization of semi-infinite minimax problems. The main effect of the active-set strategy
is to dramatically reduce the number of gradient calculations needed in the optimization. Discretization of multidimensional
domains gives rise to minimax problems with thousands of component functions. We present an application to minimizing the
sum of squares of the Lagrange polynomials to find good points for polynomial interpolation on the unit sphere in ℝ3. Our numerical results show that the active-set strategy results in a modified Armijo gradient or Gauss-Newton like methods
requiring less than a quarter of the gradients, as compared to the use of these methods without our active-set strategy. Finally,
we show how this strategy can be incorporated in an algorithm for solving semi-infinite minimax problems. 相似文献