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991.
Lewinsohn Peter M.; Zieler Ronald e.; Libet Julian; Eyeberg Sheila; Nielson Gary 《Canadian Metallurgical Quarterly》1972,81(2):248
Tested 2 groups of brain-damaged patients (n = 60 and 17) and 2 groups of controls (n = 28 and 7) on 4 different short-term memory tasks, each designed to measure the amount of information registered (0-sec delay recall) and retained after a delay of 10 sec. in 1 of 3 (visual, auditory, and kinesthetic) sensory modalities, using a variety of stimulus materials. Differences between the brain-damaged and control groups were largely due to the reduced capacity of the brain damaged to register information. Ss with anterior cerebral damage did more poorly than Ss with posterior damage on both visual and auditory short-term memory tasks. No significant differences were found between right- and left-hemisphere-damaged Ss. (26 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
992.
Flockhart GM Maier RR Barton JS MacPherson WN Jones JD Chisholm KE Zhang L Bennion I Read I Foote PD 《Applied optics》2004,43(13):2744-2751
We describe the characterization of the temperature and strain responses of fiber Bragg grating sensors by use of an interferometric interrogation technique to provide an absolute measurement of the grating wavelength. The fiber Bragg grating temperature response was found to be nonlinear over the temperature range -70 degrees C to 80 degrees C. The nonlinearity was observed to be a quadratic function of temperature, arising from the linear dependence on temperature of the thermo-optic coefficient of silica glass over this range, and is in good agreement with a theoretical model. 相似文献
993.
994.
Extended microscale crystal defects, including dislocations and stacking faults, can radically alter the properties of technologically important materials. Determining the atomic structure and the influence of defects on properties remains a major experimental and computational challenge. Using a newly developed simulation technique, the structure of the 1/2a <100> screw dislocation in nanoporous zeolite A has been modelled. The predicted channel structure has a spiral form that resembles a nanoscale corkscrew. Our findings suggest that the dislocation will enhance the transport of molecules from the surface to the interior of the crystal while retarding transport parallel to the surface. Crucially, the dislocation creates an activated, locally chiral environment that may have enantioselective applications. These predictions highlight the influence that microscale defects have on the properties of structurally complex materials, in addition to their pivotal role in crystal growth. 相似文献
995.
996.
Julian F. V. Vincent 《Applied Composite Materials》2000,7(5-6):269-271
Cellulose in the cell wall occurs in microfibrils of various sizes. Fibre should refer only to single elongated plant cells, fibre bundle to assemblages of fibres. Fibres and bundles can be of various cell types (most sclerenchyma), sizes, volume fractions of cellulose and degree of lignification. Usage of any other terms is liable to lead to confusion. Fibre bundles for industrial use should be defined only by their dimensions, botanical origin and the extraction procedures used. 相似文献
997.
Fernando Alonso-Fernandez Julian Fierrez-Aguilar Hartwig Fronthaler Klaus Kollreider Javier Ortega-Garcia Joaquin Gonzalez-Rodriguez Josef Bigun 《电信纪事》2007,62(1-2):62-82
We report on experiments for the fingerprint modality conducted during the First BioSecure Residential Workshop. Two reference systems for fingerprint verification have been tested together with two additional non-reference systems. These systems follow different approaches of fingerprint processing and are discussed in detail. Fusion experiments I volving different combinations of the available systems are presented. The experimental results show that the best recognition strategy involves both minutiae-based and correlation-based measurements. Regarding the fusion experiments, the best relative improvement is obtained when fusing systems that are based on heterogeneous strategies for feature extraction and/or matching. The best combinations of two/three/four systems always include the best individual systems whereas the best verification performance is obtained when combining all the available systems. 相似文献
998.
This paper presents a new methodology for deformable object simulation by drawing an analogy between autowaves and elastic deformation. The potential energy stored in an elastic body as a result of a deformation caused by an external force is propagated among mass points by non-linear autowaves. The novelty of the methodology is that autowave techniques are established to describe the potential energy distribution of a deformation for extrapolating internal elastic forces, and non-linear material properties are modelled with non-linear autowaves other than geometric non-linearity. A haptic virtual reality system has been developed for deformation simulation with force feedback. The proposed methodology not only deals with large-range deformations, but also accommodates isotropic, anisotropic and inhomogeneous materials by simply modifying diffusion coefficients. 相似文献
999.
Two common data representations are mostly used in intelligent data analysis, namely the vectorial and the pairwise representation. Pairwise data which satisfy the restrictive conditions of Euclidean spaces can be faithfully translated into a Euclidean vectorial representation by embedding. Non-metric pairwise data with violations of symmetry, reflexivity or triangle inequality pose a substantial conceptual problem for pattern recognition since the amount of predictive structural information beyond what can be measured by embeddings is unclear. We show by systematic modeling of non-Euclidean pairwise data that there exists metric violations which can carry valuable problem specific information. Furthermore, Euclidean and non-metric data can be unified on the level of structural information contained in the data. Stable component analysis selects linear subspaces which are particularly insensitive to data fluctuations. Experimental results from different domains support our pattern recognition strategy. 相似文献
1000.
Among the several fabrication techniques used to construct microflow systems, the low-temperature cofired ceramics (LTCC) technology, taking advantage of its multilayer approach, is one of the most versatile ones. It permits the integration of several unitary operations of an analytical process in a modular or monolithic way. Moreover, due to its perfect compatibility with screen-printing techniques, it also permits the integration of electronic components used to control the whole system setup. In this work the design, construction, and evaluation of a miniaturized analyzer for pesticide determination that integrates a pretreatment stage, based on two mixers or reactors, and an amperometric detection system to measure the product of an enzymatic inhibition reaction are presented. The detection system was monolithically integrated in the microfluidic platform, and it consisted of a screen-printed reference electrode and two platinum sheets, acting as auxiliary and working electrodes, which were embedded within the ceramic structure. The miniaturized system was characterized and successfully evaluated by determining carbofuran at the nanomolar level. 相似文献