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51.
Odors seem to be perceived differently when presented ortho- or retronasally. In this study, stimuli of controlled concentration and duration were applied in either the anterior nasal cavity or epipharynx by means of air-dilution olfactometry. Stimulus concentration was monitored in the olfactory cleft. In Experiment 1, odor thresholds to a food (chocolate) and a nonfood (lavender) odor were lower for orthonasal, compared with retronasal, stimulation. In Experiment 2, intensity ratings to suprathreshold odor concentrations were significantly higher for orthonasal than for retronasal stimulation with hydro- hydrogen sulfide, but not phenyl ethyl alcohol. Accordingly, amplitudes and latencies of olfactory event-related gen potentials to retronasal stimuli were found to be smaller and prolonged, respectively. This indicates differential processing of olfactory stimuli presented through the retronasal or orthonasal routes. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
52.
Xinke Xiao 《Engineering Fracture Mechanics》2007,74(16):2639-2641
This note is concerned with a surface semi-circular crack by using the fracture analysis software FRANC3D developed by a fracture mechanics investigation group of Cornell University. Attention is specifically paid to the effect of the boundaries parallel to the crack on the stress intensity factors (SIFs). 相似文献
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54.
Motion picture films are susceptible to local degradations such as dust spots. Other deteriorations are global such as intensity
and spatial jitter. It is obvious that motion needs to be compensated for before the detection/correction of such local and
dynamic defects. Therefore, we propose a hierarchical motion estimation method ideally suited for high resolution film sequences.
This recursive block-based motion estimator relies on an adaptive search strategy and Radon projections to improve processing
speed. The localization of dust particles then becomes straightforward. Thus, it is achieved by simple inter-frame differences
between the current image and motion compensated successive and preceding frames. However, the detection of spatial and intensity
jitter requires a specific process taking advantage of the high temporal correlation in the image sequence. In this paper,
we present our motion compensation-based algorithms for removing dust spots, spatial and intensity jitter in degraded motion
pictures. Experimental results are presented showing the usefulness of our motion estimator for film restoration at reasonable
computational costs.
Received: 9 July 2000 / Accepted: 13 January 2002
Correspondence to:S. Boukir 相似文献
55.
Treated was an anti-plane crack perpendicular to the interface of an exponential-type FGM strip bonded to another linear-type
FGM substrate with infinite thickness. Through Fourier integral transform, the problem was reduced as a Cauchy singular integral
equation, which was further solved numerically by the Lobatto–Chebyshev collocation method. Based on the numerical solution,
the effects of the geometrical and physical parameters on the stress intensity factor (SIF) were analyzed and the following
conclusions were obtained: (a) A notable discrepancy between the interface-perpendicular crack and the interfacial one is
that, to reduce the weak-discontinuity of interface or to make the interface micro-discontinuous will not necessarily decrease
the SIF of the former, but will surely decrease that of the latter. (b) When a crack tip is situated very near to the interface
(or free surface), its SIF will be high and totally dominated by the interface (or free surface). (c) To increase the stiffness
of the FGM on one side of the interface is beneficial to preventing the crack on the other side from growing toward the interface.
Besides, some practical suggestions were further given for material design in the field of composites. 相似文献
56.
Francesco Sarti Yaacov ArkinJean Chorowicz Arnon KarnieliTeresa Cunha 《Remote sensing of environment》2003,86(2):141-149
Differential radar interferometry, using archived ERS data over the region of the Dead Sea Transform, allows to detect ground movement (subsidence or uplift) in playas within the southern Arava Valley segment of the Dead Sea Rift. These measurements are consistent with a mean displacement rate of about 0.4 cm/month, in the direction of the radar beam, during the 8-month period preceding the Nuweiba earthquake of 22 November 1995. In the 3 years following the earthquake, the measured rate was smaller by a factor of 10. These movements are not related to salt diapirs or water pumping activities in the area. The exact location, along faults, suggests a possible correlation with pre-seismic and post-seismic fault deformation.A simple fault model consistent with the observed phenomena associates the observed subsidence/uplift to right and left stepping en-echelon fault patterns related to inter-seismic tensional accumulation along the faults. Further observations are necessary on this site and similar fault areas to corroborate the correlation between seismic activity and the observed phenomena. Monitoring of these sites should continue with differential Global positioning system (GPS) measurements and radar interferometric analysis using Envisat and Radarsat as well as archived data (including J-ERS). 相似文献
57.
给出平凹谐振腔和凹平凹谐振腔失调时光轴确定方法。在二维轴对称折迭-组合腔 激光器小角度失调运行时,对非相干并和和相干并和后的输出光束的近场强度分布做了分析和模拟。结果表明:小角度失调对4cm以内的近场影响不大,光强分布仍具有高斯状分布;对4cm以外的近场影响较大,光强分布发生相应的形变,且随着失调角度变大而变大。 相似文献
58.
59.
60.
通过利用长江水体作为上覆水的里运河表层底泥的释放实验研究,分析了表层底泥中CODCr和NH3—N在静置和3种扰动条件下的释放规律,结果发现城区段底泥中CODCr和NH3—N的释放强度大于非常区段,底泥孔隙水与上覆水之间的浓度梯度增大促进了底泥中污染物质的更快更多地释放。同时得出了各个断面表层底泥中CODCr,和NH3-N的释放强度,在扰动条件下的释放强度远大于静置条件下的释放强度,底泥中污染物质的释放可能会在一定程度上影响里运河将来的调水水质。 相似文献