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991.
992.
A study was undertaken to explore the effects of fixing the mandible with a bite block on the formant frequencies of the vowels [i a u] produced by two groups of children aged 4 and 5 and 7 and 8 years. Vowels produced in both normal and bite-block conditions were submitted to LPC analysis with windows placed over the first glottal pulse and at the vowel midpoint. For both groups of children, no differences were found in the frequencies of either the first or second formant between the normal and bite-block conditions. Results are discussed in relation to theories of the acquisition of speech motor control. 相似文献
993.
Graphical procedures are used to characterize the integral {1}- and {1, 2}-inverses of the incidence matrix A of a digraph, and to obtain a basis for the space of matrices X such that AXA = 0. These graphical procedures also produce the Smith canonical form of A and a full rank factorization of A using matrices with entries from {-1, 0, 1}. It is also shown how the results on incidence matrices of oriented graphs can be used to find generalized inverses of matrices of unoriented bipartite graphs. 相似文献
994.
Privatdozent Dr.-Ing. F. Hartmann Dr.-Ing. C. Katz Dipl.-Ing. B. Protopsaltis 《Archive of Applied Mechanics (Ingenieur Archiv)》1985,55(6):440-449
Summary This paper discusses the deficiencies of boundary element stiffness matrices, gives an account of the methods proposed to circumvent these defects and proposes a new procedure to obtain symmetric stiffness matrices.
Randelemente und Symmetrie
Übersicht In diesem Aufsatz werden die Fehler diskutiert, die bei Steifigkeitsmatrizen, die mit Randelementen gewonnen wurden, auftreten, und es werden die Methoden vorgestellt, die vorgeschlagen wurden, um diese Fehler zu beheben. Ferner wird eine neue Methode vorgestellt, symmetrische Steifigkeitsmatrizen zu erhalten.相似文献
995.
996.
A general strategy for fabricating thick, optically flat photopolymer recording media with high dynamic range (M/#) that exhibit low levels of recording-induced Bragg detuning for holographic data storage is presented. In particular, media with M/# values as high as 42 in 1-mm-thick formats are obtained. We believe that these results are the first demonstration of a holographic storage medium with a dynamic range of this magnitude. In addition, we report the holographic recording and recovery of high-capacity (480-kbit) digital data pages in these media, further illustrating their data-storage capabilities. 相似文献
997.
G. T. Jones R. W. L. Jones B. W. Kennedy S. W. O'Neale A. Geiser H. Klein D. Kuhn D. R. O. Morrison G. J. van Oldenborgh P. Schmid H. Wachsmuth D. B. Miller M. M. Mobayyen S. Wainstein M. Aderholz E. Hoffmann U. F. Katz J. Kern N. Schmitz W. Wittek G. Myatt D. Radojicic F. Bullock S. Burke 《Zeitschrift fur Physik C Particles and Fields》1987,36(4):593-601
Usind data from avp and \(\bar v\) p experiment with BEBC at CERN, the rates for inclusive production ofD *+,Λ c + andD 0 invp scattering and ofD *? in \(\bar v\) p scattering are measured. Some examples of the exclusive production ofD *+,Λ c + and∑ c ++ are given. The cross section for the reactionvp→μ ? c ++ is estimated. 相似文献
998.
The Schrödinger–Langevin equation (SLE) is considered as an effective open quantum system formalism suitable for phenomenological applications involving a quantum subsystem interacting with a thermal bath. We focus on two open issues relative to its solutions: the stationarity of the excited states of the non-interacting subsystem when one considers the dissipation only and the thermal relaxation toward asymptotic distributions with the additional stochastic term. We first show that a proper application of the Madelung/polar transformation of the wave function leads to a non zero damping of the excited states of the quantum subsystem. We then study analytically and numerically the SLE ability to bring a quantum subsystem to the thermal equilibrium of statistical mechanics. To do so, concepts about statistical mixed states and quantum noises are discussed and a detailed analysis is carried with two kinds of noise and potential. We show that within our assumptions the use of the SLE as an effective open quantum system formalism is possible and discuss some of its limitations. 相似文献
999.
Energetic N‐Nitramino/N‐Oxyl‐Functionalized Pyrazoles with Versatile π–π Stacking: Structure–Property Relationships of High‐Performance Energetic Materials
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Dr. Ping Yin Dr. Lauren A. Mitchell Dr. Damon A. Parrish Prof. Dr. Jean'ne M. Shreeve 《Angewandte Chemie (International ed. in English)》2016,55(46):14409-14411
N‐Nitramino/N‐oxyl functionalization strategies were employed to investigate structure–property relationships of energetic materials. Based on single‐crystal diffraction data, π–π stacking of pyrazole backbones can be tailored effectively by energetic functionalities, thereby resulting in diversified energetic compounds. Among them, hydroxylammonium 4‐amino‐3,5‐dinitro‐1H‐pyrazol‐1‐olate and dipotassium N,N′‐(3,5‐dinitro‐1H‐pyrazol‐1,4‐diyl)dinitramidate, with unique face‐to‐face π–π stacking, can be potentially used as a high‐performance explosive and an energetic oxidizer, respectively. 相似文献
1000.
P. L. Katz 《Journal of Optimization Theory and Applications》1975,15(3):249-284
A computing algorithm, based on the geometry of certain reachable sets, is presented for fixed terminal time optimal regular problems having differential equations \(\dot x = f(x ,u , t)\) . Admissible controls must be measurable and have values in a setU, which must be compact, but need not be convex. Functionsf(x, u, t) andf x (x, u, t) must be continuous and Lipschitz inx andu, but existence off u (x, u, t) or second derivatives is not required. The algorithm is based on taking a sequence of nonlinear steps, each of which linearizes \(\dot x = f(x ,u , t)\) in state only, about a current nominal control and trajectory. Small perturbations are assured by keeping the perturbed controlclose to the nominal control. In each nonlinear step, a regulator problem,linear in state, is solved by a convexity method of Barr and Gilbert (Refs. 1–2), which is undeterred by the possibility of singular arcs. The resulting control function is substituted into the original nonlinear differential equations, producing an improved trajectory. Convergence of the algorithm is not proved, but demonstrated by a computing example, known to be singular. In addition, procedures are described for choosing parameters in the algorithm and for testing for theplausibility of convergence. 相似文献