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1.
The results of research on the processing of morphologically complex words are consistent with a lexical system that activates both whole-word and constituent representations during word recognition. In this study, we focus on written production and examine whether semantically priming the first constituent of a compound influences the ease of producing a compound (as measured by typing latencies), and whether any such priming effect depends on the semantic transparency of the compound’s constituents. We found that semantic transparency of the constituents affects whether semantic priming results in changes to processing. However, it is not only the semantic transparency of the primed constituent that exerts an influence—for example, the semantic transparency of the head affects whether semantically priming the modifier results in a change in typing times. We discuss these effects in terms of competition among the various representations as the compound is output, such that overall performance is a combination of facilitation and inhibition that changes over the course of the output.  相似文献   

2.
To develop a portable device for measuring the donor corneal transparency and validate its efficacy for corneal evaluation in the eye-banks and for research. The transparency device (TD) has a light source, a detachable system for corneal insertion and a base for light transmission. The probe detects the transmitted light which is measured by a lux-meter. A contact lens was set as ‘control’ to reduce the light scattering concern, an empty petri-plate as ‘blank’ and the cornea as ‘sample’. Two experts and non-experts (masked) observed the corneas for subjective analysis which was then compared using the TD. The parameters observed were scars, foreign-body, stromal-deformities, folds, thickness and opacity which were then converted to a relative overall percentage by the observer. Twenty corneas were evaluated for correlation, five tissues to obtain standard-deviation and twenty-four pairs for a comparative study. Experts mimicked the eye-banks with long-term experience while non-experts mimicked the emerging eye-banks. Subjective values by the experts closely resembled the measurements by TD. The average correlation between the experts and the non-experts to TD was 0.985 and 0.960 respectively. TD showed higher reproducibility than experts followed by the non-experts. The comparative study showed that increase in thickness reduces the transparency. TD is portable, easy, efficient, maintains sterility and less expensive hence the emerging eye-banks and researchers can use to raise their standards and evaluate the transparency for in vitro tests and comparative studies. The suitable transparency for the cornea deemed for clinical applications was found to be >75 %.  相似文献   

3.
We have numerically investigated an analog of electromagnetically induced transparency (EIT) in a metal-dielectric-metal (MDM) waveguide bend. The geometry consists of two asymmetrical stubs extending parallel to an arm of a straight MDM waveguide bend. Finite-difference time-domain simulations show that a transparent window is located at 1550 nm, which is the phenomenon of plasmonic-induced transparency (PIT). Signal wavelength is assumed to be 820 nm. The velocity of the plasmonic mode can be largely slowed down while propagating along the MDM bends. Multiple-peak plasmon-induced transparency can be realized by cascading multiple cavities with different lengths and suitable cavity-cavity separations. Large group index up to 73 can be obtained at the PIT window. Our proposed configuration may thus be applied to storing and stopping light in plasmonic waveguide bends. In addition, the relationship between the transmission characteristics and the geometric parameters including the radius of the nano-ring, the coupling distance, and the deviation length between the stub and the nano-ring is studied in a step further. The velocity of the plasmonic mode can be largely slowed down while propagating along the MDM bends. For indirect coupling, formation of transparency window is determined by resonance detuning, but, evolution of transparency is mainly attributed to the change of the coupling distance. Theoretical results may provide a guideline for control of light in highly integrated optical circuits. The characteristics of our plasmonic system indicate a significant potential application in integrated optical circuits such as optical storage, ultrafast plasmonic switch, highly performance filter, and slow light devices.  相似文献   

4.
Despite the prevalence and importance of transparency in organisms, particularly pelagic species, it is a poorly understood characteristic. This article reviews the current state of knowledge on the distribution, ecology, and physical basis of biological transparency. Particular attention is paid to the distribution of transparent species relative to their optical environment, the relationship between transparency and visual predation, the physics of transparency, and what is known about the anatomical and ultrastructural modifications required to achieve this condition. Transparency is shown to be primarily a pelagic trait, uncommon in other aquatic habitats and extremely rare on land. Experimental and theoretical studies in terrestrial, freshwater, and marine ecosystems have shown that transparency is a successful form of camouflage, and that several visual adaptations seem to counter it. The physical basis of transparency is still poorly understood, but anatomical observations and mathematical models show that there are various routes to transparency. Future avenues for research include examination of the ultrastructure and optical properties of transparent tissue, exploring the link between transparent species and special visual modifications in the species they interact with, and analysis of the evolution of transparency using comparative methods.  相似文献   

5.
The lateral line system of the zebrafish offers the qualities of simplicity, accessibility and reproducibility which are most appropriate for the analysis of neural development and pattern formation in vertebrates. Furthermore, the transparency of the fish embryos allows the application of a variety of optical and molecular methods in the living animal, which is essential for a more complete analysis of the system.  相似文献   

6.
SUMMARY

Some water transparency characteristics (Secchi disc transparency, mean diffuse light attenuation coefficient and turbidity) of a number of South African impoundments are compared. In general most impoundments may be considered to be highly turbid; for 92 impoundments considered in this paper the modal mean Secchi disc transparency was in the class 0 to 0,5 m. The geographical distribution of water transparency within South Africa shows good agreement with the geographical distribution of sediment production, indicating that suspended inorganic material is the dominant factor governing water transparency in most impoundments. There is evidence that eutrophication and mineralization are processes which lead to increased water transparency. High turbidity and its role in influencing the limnology and management of impoundments is discussed. More in-depth investigations are needed to evaluate the contributions by coloured substances, suspended silt and phytoplankton to light attenuation within individual impoundments.  相似文献   

7.
8.
Huang  Ben  Meng  Hongyun  Wang  Qinghao  Wang  Huihao  Zhang  Xing  Yu  Wei  Tan  Chunhua  Huang  Xuguang  Wang  Faqiang 《Plasmonics (Norwell, Mass.)》2016,11(2):543-550
Plasmonics - A compact plasmonic system based on a stub metal-insulator-metal (MIM) waveguide coupled with a nanodisk resonator for plasmonic-induced transparency (PIT) has been proposed and...  相似文献   

9.
Plasmonics - A new framework of high-selective plasmonic-induced reflectance (PIR) in a plasmonic-induced transparency (PIT) system is presented by using planar dielectric-metal-dielectric (DMD)...  相似文献   

10.
Broadband light transparency of metallic structures has long been pursued due to the potential applications in the optoelectronic communications, flat panel displays, and clean solar energy. Considerable efforts have been made on the multiband electromagnetic wave transparency of plasmonic metamolecules. However, far less work has been focused on the multispectral light transparency of a seamless metal film. Here, we for the first time propose a seamless metal film structure coated by double conventional plasmonic crystals and demonstrate the observed multispectral broadband light transparency behavior. A maximum transmittance larger than 92 % is achieved. The average transmittance of the whole spectral range from 550 to 1,100 nm is exceeding 45.8 %, suggesting the achievement of an ultra-broadband semi-transparent window. Particularly, the transparency features are highly scalable by tuning the structural parameters. Plasmonic resonances and the metallic particle–film plasmonic interactions are responsible for the observed optical transparency properties. These findings and merits make the proposed structure a good candidate for numerous potential applications, including the optoelectronic components, transparent displayers, and light harvesting.  相似文献   

11.
The eye lens is the foremost biological system where function is directly under control of the physico-chemical properties of the cytoplasmic macromolecular solution. Indeed, lens transparency and opacity, lens refractive index gradient and viscosity, are the result of the structural and interactive properties of the crystallins, of their stability, of the fine tuning of their interaction potentials and associations at different levels of organization. Among the different crystallin classes, -crystallins have represented a major challenge for a long time. The -crystallin secondary, tertiary and quaternary structures are still unknown. On the functional side, however, it is established that -crystallin quaternary structure and repulsive interactions determine lens transparency, whereas the -crystallin chaperone effect most probably plays a role in the aging process. In the present paper, we recall the physico-chemical properties and the quaternary structure features of -crystallins that were demonstrated to control light scattering and transparency. The interest of a crystallin mixture for lens function is discussed. Then, a formal approach is proposed to design models for the -crystallin quaternary structure, including the question of whether -crystallins assemble with symmetry. An hypothesis relevant to the fold of the -crystallin C-terminal domain is presented in another paper in this issue.  相似文献   

12.
13.
Dye‐sensitized solar cells (DSCs) have attracted great interest as one of the most promising photovoltaic technologies, and transparent DSCs show potential applications as photovoltaic windows. However, the competition between light absorption for photocurrent generation and light transmittance for obtaining high transparency limits the performance of transparent DSCs. Here, transparent DSCs exhibiting a high light transmittance of 60.3% and high energy conversion efficiency (3.66%) are reported. The strategy is to create a cocktail system composed of ultraviolet and near‐infrared dye sensitizers that selectively and efficiently harvest light in the invisible or low‐eye‐sensitivity region while transmitting light in high‐eye‐sensitivity regions. This new design provides a reasonable approach for realizing high efficiency and transparency DSCs that have potential applications as photovoltaic windows.  相似文献   

14.
The lens and cornea combine to form a single optical element in which transparency and refraction are the fundamental biophysical characteristics required for a functional visual system. Although lens and cornea have different cellular and extracellular specializations that contribute to transparency and refraction, their development is closely related. In the embryonic mouse, the developing cornea and lens separate early. In contrast, zebra fish lens and cornea remain connected during early development and the optical properties of the cornea and lens observed by slit lamp and quasielastic laser light scattering spectroscopy (QLS) are more similar in the zebra fish eye than in the mouse eye. Optical similarities between cornea and lens of zebra fish may be the result of similarities in the cellular development of the cornea and lens.  相似文献   

15.
When judging the lightness of objects, the visual system has to take into account many factors such as shading, scene geometry, occlusions or transparency. The problem then is to estimate global lightness based on a number of local samples that differ in luminance. Here, we show that eye fixations play a prominent role in this selection process. We explored a special case of transparency for which the visual system separates surface reflectance from interfering conditions to generate a layered image representation. Eye movements were recorded while the observers matched the lightness of the layered stimulus. We found that observers did focus their fixations on the target layer, and this sampling strategy affected their lightness perception. The effect of image segmentation on perceived lightness was highly correlated with the fixation strategy and was strongly affected when we manipulated it using a gaze-contingent display. Finally, we disrupted the segmentation process showing that it causally drives the selection strategy. Selection through eye fixations can so serve as a simple heuristic to estimate the target reflectance.  相似文献   

16.
Recent concerns about the reproducibility of science have led to several calls for more open and transparent research practices and for the monitoring of potential improvements over time. However, with tens of thousands of new biomedical articles published per week, manually mapping and monitoring changes in transparency is unrealistic. We present an open-source, automated approach to identify 5 indicators of transparency (data sharing, code sharing, conflicts of interest disclosures, funding disclosures, and protocol registration) and apply it across the entire open access biomedical literature of 2.75 million articles on PubMed Central (PMC). Our results indicate remarkable improvements in some (e.g., conflict of interest [COI] disclosures and funding disclosures), but not other (e.g., protocol registration and code sharing) areas of transparency over time, and map transparency across fields of science, countries, journals, and publishers. This work has enabled the creation of a large, integrated, and openly available database to expedite further efforts to monitor, understand, and promote transparency and reproducibility in science.

This study uses novel open source automated tools to monitor transparency across all 2.75 million open access articles on PubMed Central, discovering that different disciplines, journals and publishers abide by principles of transparency to varying degrees over time.  相似文献   

17.
We present models of semantic transparency in which the perceived transparency of English noun–noun compounds, and of their constituent words, is predicted on the basis of the expectedness of their semantic structure. We show that such compounds are perceived as more transparent when the first noun is more frequent, hence more expected, in the language generally; when the compound semantic relation is more frequent, hence more expected, in association with the first noun; and when the second noun is more productive, hence more expected, as the second element of a noun–noun compound. Taken together, our models of compound and constituent transparency lead us to two conclusions. Firstly, although compound transparency is a function of the transparencies of the constituents, the two constituents differ in the nature of their contribution. Secondly, since all the significant predictors in our models of compound transparency are also known predictors of processing speed, perceived transparency may itself be a reflex of ease of processing.  相似文献   

18.
SUMMARY 1. Macrophyte abundance and distribution was assessed in a chain of six interconnected lakes (all with the same flooding frequency) in the Arctic, where increasing distance from the Mackenzie River channel resulted in a gradient of water transparency (‘chain‐set’ lakes), and in a group of 26 spatially discrete lakes where increasing frequency and duration of lake flooding with river water (controlled by sill height) also resulted in a transparency gradient (‘sill‐set’ lakes). 2. Among the chain‐set lakes, above‐ground macrophyte biomass increased from 0 to 1000 g m?2 with increasing water transparency. Among the sill‐set lakes, the transparency gradient among the lakes was less well defined and the relations with biomass were more varied. A decrease in flooding was associated with increasing water transparency and an increasing biomass of macrophytes from about 0 to over 2000 g m?2. For a specific flood frequency, however, the effect of flooding was much greater when lakes were directly connected to a river channel than when floodwaters flowed first through an intervening lake. Among infrequently flooded lakes the effect of flooding on water transparency and biomass was negligible. 3. Among relatively clear lakes in both sets of lakes, biomass increased with increasing water transparency and decreasing lake depth. Among relatively turbid lakes, however, biomass increased with the combined effect of increasing water colour (decreasing water transparency) and increasing lake water depth. The increases in biomass with increasing water colour (coloured dissolved organic matter) and increasing depth, which together result in reduced light at the bed, may be explained by reduced exposure to ultra violet light. 4. An average light attenuation of 1.3 m?1 (Secchi depth about 1 m) over the growing season appears to represent a threshold water transparency which, in combination with water depths early in the growing season, is consistent with a light supply on the bed required for growth of the common macrophytes in lakes of the Mackenzie Delta. However, a comparison with other systems indicates that macrophytes among lakes of the Mackenzie Delta grow deeper, for a given level of transparency, than is reported in lakes at lower latitude, despite the lower sun angles and increased reflectivity of water surfaces in the arctic. 5. A complete accounting of water transparency (at PAR and UV wavelengths), lake depth, summer sun angle and duration of sunlight may be necessary to explain patterns of macrophyte growth among lakes across a full range of latitudes.  相似文献   

19.
The soluble proteins present in the ocular lens impart important optical and dynamic mechanical properties on the lens. The short-range order of crystallin proteins grants transparency to a very concentrated protein solution. This unique protein system directly enables proper visual function of the eye. These proteins were investigated in steady and oscillatory shear. Steady shear data were fitted with a modified Herschel-Bulkley yield stress model that allows for a Newtonian plateau at low shear rates. The Cox-Merz rule was used in conjunction with large amplitude oscillatory shear to give insight into the degradation of the fluid structure with increasing strain. The shear thinning viscoelastic behavior of these proteins gives rise to beneficial mechanical properties and results from the same short-range order granting optical transparency.  相似文献   

20.
The analysis of motion crowds is concerned with the detection of potential hazards for individuals of the crowd. Existing methods analyze the statistics of pixel motion to classify non-dangerous or dangerous behavior, to detect outlier motions, or to estimate the mean throughput of people for an image region. We suggest a biologically inspired model for the analysis of motion crowds that extracts motion features indicative for potential dangers in crowd behavior. Our model consists of stages for motion detection, integration, and pattern detection that model functions of the primate primary visual cortex area (V1), the middle temporal area (MT), and the medial superior temporal area (MST), respectively. This model allows for the processing of motion transparency, the appearance of multiple motions in the same visual region, in addition to processing opaque motion. We suggest that motion transparency helps to identify “danger zones” in motion crowds. For instance, motion transparency occurs in small exit passages during evacuation. However, motion transparency occurs also for non-dangerous crowd behavior when people move in opposite directions organized into separate lanes. Our analysis suggests: The combination of motion transparency and a slow motion speed can be used for labeling of candidate regions that contain dangerous behavior. In addition, locally detected decelerations or negative speed gradients of motions are a precursor of danger in crowd behavior as are globally detected motion patterns that show a contraction toward a single point. In sum, motion transparency, image speeds, motion patterns, and speed gradients extracted from visual motion in videos are important features to describe the behavioral state of a motion crowd.  相似文献   

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