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S. B. Ellis S. J. Kiehl W. S. Hughes K. Schwabe W. C. Gardiner H. L. Sanders H. Yoshimura Hanna Jablezynska-Jedrzewska J. Domański W. A. Dorfman P. Nylén Barbara Stone F. Hovorka W. C. Dearing E. Biilmann W. Kordatzki P. Wulff G. Florence A. Drilhon P. Szigeti O. Tomiček F. Poupě O. Redlich W. Stricks 《Analytical and bioanalytical chemistry》1937,111(2-4):94-104
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The electro-optic response of ferroelectric smectic C* liquid crystals has been studied. Anomalous switching behaviour of such materials which possess a negative dielectric anisotropy has been reported. These materials show a minimum in response time at a sufficiently high field. We present results showing the dependency of this minimum upon spontaneous polarisation and the effect of AC bias. Calculations based upon the equation of motion of the director around the cone are presented which describe this effect and its dependence on the relative magnitudes of the spontaneous polarization and dielectric anisotropy of the material. Good agreement with the experimental results is found. 相似文献
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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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In a previous paper we gave a new formulation and derived the Euler equations and other necessary conditions to solve strong, pathwise, stochastic variational problems with trajectories driven by Brownian motion. Thus, unlike current methods which minimize the control over deterministic functionals (the expected value), we find the control which gives the critical point solution of random functionals of a Brownian path and then, if we choose, find the expected value.This increase in information is balanced by the fact that our methods are anticipative while current methods are not. However, our methods are more directly connected to the theory and meaningful examples of deterministic variational theory and provide better means of solution for free and constrained problems. In addition, examples indicate that there are methods to obtain nonanticipative solutions from our equations although the anticipative optimal cost function has smaller expected value.In this paper we give new, efficient numerical methods to find the solution of these problems in the quadratic case. Of interest is that our numerical solution has a maximal, a priori, pointwise error of O(h3/2) where h is the node size. We believe our results are unique for any theory of stochastic control and that our methods of proof involve new and sophisticated ideas for strong solutions which extend previous deterministic results by the first author where the error was O(h2).We note that, although our solutions are given in terms of stochastic differential equations, we are not using the now standard numerical methods for stochastic differential equations. Instead we find an approximation to the critical point solution of the variational problem using relations derived from setting to zero the directional derivative of the cost functional in the direction of simple test functions.Our results are even more significant than they first appear because we can reformulate stochastic control problems or constrained calculus of variations problems in the unconstrained, stochastic calculus of variations formulation of this paper. This will allow us to find efficient and accurate numerical solutions for general constrained, stochastic optimization problems. This is not yet being done, even in the deterministic case, except by the first author. 相似文献
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A new set of matrix addressing schemes for ferroelectric liquid crystal displays is reported. The schemes use the minimum in the response time-voltage characteristic found in certain mixtures and deliver improved operating speed and contrast ratio compared with previously reported schemes operating in this mode. 相似文献
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