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L R Bernstein 《The Journal of the Acoustical Society of America》1991,89(3):1306-1313
Several investigations suggest that sensitivity to changes in interaural disparities within select spectral regions may be degraded by the presence of energy at other, even remote, spectral regions. This study assessed whether similar degradations would be observed in an MLD paradigm. Detection thresholds were measured for NoSo and NoS pi. The signal, an 800-Hz tone (100-ms), was presented in continuous, broadband noise. Thresholds were also measured in the presence of a 400-Hz tone (the interferer) presented with an interaural phase disparity of 180 degrees and gated simultaneously with the signal or presented continuously. NoS pi thresholds increased by about 7 dB with the gated interferer at 80 dB SPL. Smaller increases were observed with lower levels of the interferer. Presenting the interferer continuously reduced substantially its effect. NoSo thresholds were affected only slightly by the interferer. Reversing the roles of the signal and interferer (400-Hz signal, 800-Hz interferer) led to smaller, but reliable degradations in performance. Diotic interferers had, in general, smaller effects on performance. The possible relation between the mechanisms that produce interference and those that foster an ability to segregate sources of sound is discussed. 相似文献
3.
Ashwani K. Padthe Nalin A. Chaturvedi Dennis S. Bernstein Sanjay P. Bhat Anthony M. Waas 《International Journal of Non》2008,43(4):277-291
We study a linearly damped preloaded two-bar linkage that exhibits hysteresis due to the presence of multiple attracting equilibria. The dynamics at the unstable equilibrium, through which a snap-through buckle occurs, are not linearizable due to a solution-dependent singularity. We stabilize the unstable equilibrium using two distinct non-linear controllers. The feedback-linearization controller requires knowledge of the linkage parameters, whereas the robust version of the intrinsic non-linear proportional-derivative controller requires only an upper bound on the stiffness. 相似文献
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Mishra SR Bachmann KT Bernstein RH Blair RE Foudas C Lefmann WC Leung WC Oltman E Quintas PZ Sciulli FJ Shaevitz MH Smith WH Merritt FS Oreglia MJ Schellman H Schumm BA Borcherding F Fisk HE Lamm MJ Marsh W Merritt KW Yovanovitch DD Bodek A Budd HS Sakumoto WK 《Physical review letters》1989,63(2):132-135
7.
One important difference between the results of collinear and of full 3-D dynamical computations arises from the difference in the available volume in phase space (1-D versus 3-D) which can be termed a “dimensionality-bias”. Correction for this phase space factor allows for a more realistic estimate of reaction cross sections, branching ratios and 3-D product energy distributions from collinear calculations. 相似文献
8.
Solutions of cesium tri-iodide and potassium iodide and iodine in water show a strong resonance Raman effect of the I−3 ion when excited by the ultraviolet lines at 3638 and 3511 Å of an argon ion laser, High intensity overtone progressions of the “symmetric” vibration νi were observed. This progression allows the confirmation of the presence of the I−3 ion in iodine-methanol solutions. 相似文献
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Powell BJ Baruah T Bernstein N Brake K McKenzie RH Meredith P Pederson MR 《The Journal of chemical physics》2004,120(18):8608-8615
We report first-principles density-functional calculations for hydroquinone (HQ), indolequinone (IQ), and semiquinone (SQ). These molecules are believed to be the basic building blocks of the eumelanins, a class of biomacromolecules with important biological functions (including photoprotection) and with the potential for certain bioengineering applications. We have used the difference of self-consistent fields method to study the energy gap between the highest occupied molecular orbital and the lowest unoccupied molecular orbital, Delta(HL). We show that Delta(HL) is similar in IQ and SQ, but approximately twice as large in HQ. This may have important implications for our understanding of the observed broadband optical absorption of the eumelanins. The possibility of using this difference in Delta(HL) to molecularly engineer the electronic properties of eumelanins is discussed. We calculate the infrared and Raman spectra of the three redox forms from first principles. Each of the molecules have significantly different infrared and Raman signatures, and so these spectra could be used in situ to nondestructively identify the monomeric content of macromolecules. It is hoped that this may be a helpful analytical tool in determining the structure of eumelanin macromolecules and hence in helping to determine the structure-property-function relationships that control the behavior of the eumelanins. 相似文献