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31.
The effectiveness of antenna and spread-spectrum diversity is evaluated for direct-sequence differential phase-shift-keyed signaling over a worst-case pulse-jammed multipath-fading channel. Two diversity combining techniques are proposed. One uses predetection selective combining followed by postdetection equal-gain combining, and the other uses only postdetection equal-gain combining. The use of coding with hard and soft decision decoding is also considered. It is shown that the proposed diversity techniques can provide a significant improvement in the performance of coded antijam systems operating over jammed multipath-fading channels 相似文献
32.
This study examined the behavioral differences among liked and disliked hyperactive children and their normal peers during joint activities. 25 hyperactive children and 39 normal control subjects were selected and observed in high- and low-structured play settings (counterbalanced for order) in one of 3 dyadic groupings (10 liked hyperactive children, each with a control; 15 disliked hyperactive children, each with a control; and 7 control–control pairs). For the most part, the differences observed did not depend on setting or gender comparisons. Hyperactive children were more active, talkative, and physically off-task than their peers, but they made fewer positive social statements. Disliked hyperactive children made more negative statements with accompanying negative physical interactions. Specifically, in response to disliked hyperactive children, normal partners became more negative and active, were less talkative and cooperative, and engaged in more solitary play than when playing with other normal children. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
33.
Audrey L. Smith Alexandria P. Eiken Sydney A. Skupa Dalia Y. Moore Lelisse T. Umeta Lynette M. Smith Elizabeth R. Lyden Christopher R. DAngelo Avyakta Kallam Julie M. Vose Tatiana G. Kutateladze Dalia El-Gamal 《International journal of molecular sciences》2022,23(12)
B-cell chronic lymphocytic leukemia (CLL) results from intrinsic genetic defects and complex microenvironment stimuli that fuel CLL cell growth through an array of survival signaling pathways. Novel small-molecule agents targeting the B-cell receptor pathway and anti-apoptotic proteins alone or in combination have revolutionized the management of CLL, yet combination therapy carries significant toxicity and CLL remains incurable due to residual disease and relapse. Single-molecule inhibitors that can target multiple disease-driving factors are thus an attractive approach to combat both drug resistance and combination-therapy-related toxicities. We demonstrate that SRX3305, a novel small-molecule BTK/PI3K/BRD4 inhibitor that targets three distinctive facets of CLL biology, attenuates CLL cell proliferation and promotes apoptosis in a dose-dependent fashion. SRX3305 also inhibits the activation-induced proliferation of primary CLL cells in vitro and effectively blocks microenvironment-mediated survival signals, including stromal cell contact. Furthermore, SRX3305 blocks CLL cell migration toward CXCL-12 and CXCL-13, which are major chemokines involved in CLL cell homing and retention in microenvironment niches. Importantly, SRX3305 maintains its anti-tumor effects in ibrutinib-resistant CLL cells. Collectively, this study establishes the preclinical efficacy of SRX3305 in CLL, providing significant rationale for its development as a therapeutic agent for CLL and related disorders. 相似文献
34.
Administered 2 forms of the Stroop Color-Word Interference Test and 3 scales derived from the MMPI to 26 male and 25 female undergraduates. Results raise questions about traditional interpretations of the color-word test as conflict-free measure of cognitive style and about the degree to which cognitive ability measures are saturated with modality-specific variance that is ordinarily overlooked. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
35.
Shrinking feature sizes, combined with the need for low-power and lightweight components, fuel the desire to place large mixed-signal systems onto a single die. A major design issue in mixed-signal systems is the effect of digital switching noise coupled to sensitive analog circuits through the substrate. A method is presented for minimizing this effect by partitioning digital and analog processing into separate time blocks. The resulting trade-off between lost signal and increased energy consumption is explored. As an example, a GPS synchronizer design is analyzed with respect to modifications that can be made to increase performance, while minimizing any associated energy penalty. Application of the partitioning method to other communications systems is discussed. 相似文献
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38.
Summary The aluminum di-soaps appear to have a crystal structure analogous to the sodium soaps, that is, the metal atoms are arranged
in a double layer from which the fatty acid radicals extend in opposite directions, end to end. Hence in the aluminum di-soaps
the two acid radicals attached to any aluminum atom lie side by side. Aluminum di-soaps produced by precipitation and extraction
at higher temperatures have a monoclinic angle of 48°. Those produced at low temperature and extracted at low temperature
have a higher value, β, of 60°.
Bristol-Myers Company post-doctorate fellow in chemistry; now associate professor of chemistry, University of Alabama. 相似文献
39.
Atomic transport in the presence of a temperature gradient, commonly known as thermotransport or the thermomigration phenomenon, was simulated for U-Zr alloys using a phase-field model derived from irreversible thermodynamics. The free energy of the U-Zr system, a necessary ingredient for the phase-field-model, was directly incorporated from the available thermodynamic database. Kinetic parameters such as atomic mobility and heat of transport terms were obtained from experimental values reported in the literature. The model was applied to a single-phase (bcc-γ phase) alloy and to a diffusion couple consisting of two single-phase (bcc-γ phase) alloys of different compositions, both subjected to a constant temperature gradient. Constituent redistribution in the absence and presence of a compositional gradient was examined. An enrichment of Zr with a corresponding depletion of U was observed at the hot end of the initially homogeneous single-phase alloy. A similar atomic transport behavior was observed in the diffusion couple, where the magnitude and direction of the final composition gradient was dictated by the combined influence of atomic mobility and heat of transport terms. 相似文献
40.
M. B. Bush 《Computational Mechanics》1991,7(3):195-204
A boundary integral equation formulation is used to model the stratified flow of two Newtonian viscous liquids, in which the geometrical detail of the interface between the layers is not known in advance. The technique is tested by comparing predictions with the results of previous finite element solutions, and found to perform well. Finally, the method is used to examine the two-layer jet theory of Tanner (1980) as a means of simplifying the modelling of complex extrudate swell problems. 相似文献