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131.
Chow Sy-Miin; Haltigan John D.; Messinger Daniel S. 《Canadian Metallurgical Quarterly》2010,10(1):101
We examined dynamic infant–parent affect coupling using the Face-to-Face/Still-Face (FFSF). The sample included 20 infants whose older siblings had been diagnosed with Autism Spectrum Disorders (ASD-sibs) and 18 infants with comparison siblings (COMP-sibs). A series of mixed effects bivariate autoregressive models was used to represent the self-regulation and interactive dynamics of infants and parents during the FFSF. Significant bidirectional affective coupling was found between infants and parents, with infant-to-parent coupling being more prominent than parent-to-infant coupling. Further analysis of within-dyad dynamics revealed ongoing changes in concurrent infant–parent linkages both within and between different FFSF episodes. The importance of considering both inter- and intradyad differences is discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
132.
Power distribution systems have been significantly affected by many fault causing events. Effective outage cause identification can help expedite the restoration procedure and improve the system reliability. However, the data imbalance issue in many real-world data often degrades the outage cause identification performance. In this paper, artificial immune recognition system (AIRS), an immune-inspired algorithm for supervised classification task is applied to the Duke Energy outage data for outage cause identification using three major causes (tree, animal, and lightning) as prototypes. The performance of AIRS on these real-world imbalanced data is compared with an artificial neural network (ANN). The results show that AIRS can greatly improve the performance by as much as 163% when the data are imbalanced and achieve comparable performance with ANN for relatively balanced data 相似文献
133.
Kwok Y. Chow Joseph Go David J. W. Grant 《Drug development and industrial pharmacy》1986,12(3):247-264
Adipic acid crystallized from water containing various concentrations of hexanoic, octanoic or undecanoic acid was examined using differential scanning calorimetry (DSC), density measurements and dissolution rates. Parallel decreases (and increases) in the enthalpy of fusion (Δhf), entropy of fusion (ΔSf) and melting point (Tm) were observed; these changes correspond to increases (and decreases) of both the crystal energy and the concentration of crystal imperfections, resulting from the presence of additives in the crystals. When the crystals were well wetted, the rate of dissolution was inversely related to ΔHf, Tm and ΔSf in agreement with the usual assumption that “impurity” defects increase the energy and consequently enhance the dissolution rate of the crystals. The initial dissolution rate of the crystals, however, decreased with decreasing ΔHf, Tm and ΔSf, suggesting a reduction of wettability which may be caused by an associated increase in the concentration of surface irregularities. DSC appears to be a more sensitive indicator of crystal imperfection than density for doped adipic acid crystals. 相似文献
134.
135.
Weng Chow 《Quantum Electronics, IEEE Journal of》1986,22(8):1174-1183
We investigated the behavior of two lasers operating with coupled resonators. Our analysis involves a decomposition of the laser field in terms of the passive composite resonator eigenmodes. The interaction between the laser field and the active medium is found to lead to mode coupling, The dominant coupling mechanism is cross saturation among composite-resonator modes. The effects of cross saturation on the output of the coupled lasers are investigated. Our results are valid for all values of coupling between lasers. Examples of lockbands calculated using the composite-resonator mode analysis are presented. 相似文献
136.
Electrically wavelength-tunable pulses are generated from two mutually injection-seeded Fabry-Perot laser diodes at 1 GHz. By investigating the spectral dynamics, we experimentally show that stable single-mode output can be obtained after four roundtrip propagation cycles in the external cavity. We also probe the dynamic change of the spectrum during the switching between two single-mode wavelengths. It is found that the steady states can be reached after six to seven roundtrip cycles. 相似文献
137.
A slot-excited hemispherical dielectric resonator antenna backed by a rectangular cavity is studied theoretically and experimentally. The magnetic-type dyadic Green's function for the rectangular cavity is derived using the mode-matching method. An integral equation for the equivalent magnetic current is obtained by enforcing the boundary condition across the slot. The moment method with the Galerkin's procedure is then used to find the magnetic current in the slot and, hence, the input impedance of the antenna. Measurements were carried out to verify the theory and good agreement is obtained. The effects of the slot inclination angle, of the slot offset, and of the cavity size on the input impedance are discussed 相似文献
138.
We have been exploring the mechanism of action of 5-(3,4-dichlorophenyl) methylhydantoin (hydantoin), an antiviral drug that inhibits the replication of poliovirus in culture. By varying the time of drug addition to infected cells, we found that the drug acts at a stage which is late in the replication cycle and subsequent to the step inhibited by guanidine. Furthermore, we detected normal levels of full-length plus-strand virion RNA in hydantoin-treated cultures. A new assembly intermediate in addition to the expected assembly intermediates was detected in drug-treated cultures. This intermediate has properties consistent with that of a packaging intermediate. Drug-resistant mutants were readily isolated. Sequence analysis of three independent drug-resistant mutants identified amino acid substitutions in the 2C coding region. Reconstruction by site-directed mutagenesis confirmed that these single mutations were sufficient to confer drug resistance. Taken together, these data suggest that the poliovirus 2C region is involved in virus encapsidation and that hydantoin inhibits this stage of replication. 相似文献
139.
140.
The analysis presented provides a quantitative method for predicting semiconductor laser amplifier performance in the presence of ASE (amplified spontaneous emission). It indicates that in order to increase the fraction of pump power that contributes to the amplification of the input laser field relative to that spent in overcoming internal losses, an amplifier should operate at as high an excitation level as possible. This may mean operating an amplifier above its free-running oscillation threshold. A limitation to the maximum pump power is the increase in ASE. With too high an excitation, ASE dominates over the amplified input laser field, resulting in a quenching of the amplifier gain, efficiency and coherence. ASE effects may be mitigated by increasing the input laser intensity, decreasing the amplifier facet reflectivities, or, in some cases, tuning the master oscillator so that it is resonant with the amplifier. The analysis indicates that minimizing the facet reflectivity is the most effective way to circumvent ASE limitations to power scaling semiconductor laser amplifiers 相似文献