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[en] In recent years, low-dimensional materials have received extensive attention in the field of electronics and optoelectronics. Among them, photoelectric devices based on photoconductive effect in low-dimensional materials have a broad development space. In contrast to positive photoconductivity, negative photoconductivity (NPC) refers to a phenomenon that the conductivity decreases under illumination. It has novel application prospects in the field of optoelectronics, memory, and gas detection, etc. In this paper, we review reports about the NPC effect in low-dimensional materials and systematically summarize the mechanisms to form the NPC effect in existing low-dimensional materials. (review)
[en] The structural color printing based on all-aluminum plasmonic V-groove metasurfaces is demonstrated under both bright field and dark field illumination conditions. A broad visible color range is realized with the plasmonic V-groove arrays etched on aluminum surface by simply varying the groove depth while keeping the groove period as a constant. Polarization dependent structural color printing is further achieved with interlaced V-groove arrays along both the horizontal and vertical directions. Furthermore, these results pave the way towards the use of all-aluminum structural color printing platform for many practical applications such as security marking and information storage.
[en] This paper presents a Generative Adversarial Network based on image in-painting, which can reconstruct the shape using a multi-spectral image with a laser line. One of the difficulties in multi-spectral photometric stereo is to extract the laser line, because the required illumination for multi-spectral photometric stereo, e.g. the red, green, and blue lights, may pollute the colour of the laser line. In this paper, we presents a method, which uses the Generative Adversarial Network based on image in-painting, to separate a multi-spectral image with a laser line into a clean laser image and an uncorrupted multi-spectral image without the laser line, to reconstruct the shape using a multi-spectral image with a laser line. To make the proposed method applicable to real-world objects, a rendered image dataset obtained using the rendering models in ShapeNet has been used for training the network, and the evaluation shows the superiority of the proposed approach over several previous methods, on both rendered images and real-world images. (paper)
[en] The article considers the issues related to the principles of building information models from laser method. Optical images of the speckle structures are recorded and subjected to statistical processing based on the analysis of the intensity of illumination of discrete points of the studied surfaces. The information thus obtained, saved and interpreted in the article as "phase portrait" of the system under study at a given time. The set thus obtained data is presented in the article as "phase space" of the system under study. On this basis to create an information model that is used in the form of "snapshots" of the state of (ID) in the studied points in time. The parameters of the investigated textures are recorded as statistical data and further formalized. (paper)
[en] The acoustoelectric current in graphene nanoribbons, with widths ranging between 350 nm and 600 nm, has been investigated as a function of illumination. For all nanoribbon widths, the acoustoelectric current was observed to decrease on illumination, in contrast to the increase in acoustoelectric current measured in unpatterned graphene sheet devices. This is thought to be due to the higher initial conductivities of the nanoribbons compared to unpatterned devices. (paper)
[en] In Popular Portuguese Architecture, there are a large number of buildings that we should have as a reference and whose essence should be analyzed during the rehabilitation or development of the project, in order to create a connection to the place and to keep their identity. These places, full of history and memories, give us the idea of scenarios which can be traversed and which present us with light and the surrounding nature in each opening. The introduction of the New involves its characterization in modern architecture as being the one that should be able to establish a connection to the past without destroying it and without renouncing to its means of expression. This way, these concepts reflect the importance of connecting in the same urban mesh, as a living organism, two periods in which one does not override the other, but that, in turn, add value to each other. In popular architecture, the dwelling space is adapted by Man through his way of living and experiencing the place and it can be compared to the ‘Living Machine’ of Le Corbusier. Both had to respond to the psychological, functional and spiritual needs of the people, through the building simplicity and the study of light entry in the spaces. The illumination of the spaces was not designed to the meet human needs not even those for domestic purposes. Inhabiting immediately assumes the relationship with the surroundings and the orientation of the sun, and, in this sense, illumination is one of the most important elements in architecture. The Light is the “soul” of architecture, as it gives life, movement and different dimensions and depths to it by using natural illumination during the day and artificial at night. The illumination should be part of the conceptual process of the project, as the structural part is and of everything, that is part of an architectural project and of its peculiarities. (paper)
[en] The results of 200 spectrophotometric study of five bright meteors and indentification of spectral lines are given. Distribution of energy for different points of the paths of meteors is found. Masses of meteor particles are determined on the base of integrated curves of brightness
[en] Advanced split-illumination electron holography was developed by employing two biprisms in the illuminating system to split an electron wave into two coherent waves and two biprisms in the imaging system to overlap them. A focused image of an upper condenser-biprism filament was formed on the sample plane, and all other filaments were placed in its shadow. This developed system makes it possible to obtain precise reconstructed object waves without modulations due to Fresnel fringes, in addition to holograms of distant objects from reference waves. - Highlights: • Advanced split-illumination electron holography without Fresnel fringes is developed. • Two biprisms are installed in illuminating system of microscope. • High-precision holographic observations of an area locating far from the sample edge become possible
[en] The Habitable-zone Planet Finder (HPF) is a fiber-fed precise radial velocity (RV) spectrograph at the 10 m Hobby–Eberly Telescope (HET). Due to its fixed-altitude design, the HET pupil changes appreciably across a track, leading to significant changes of the fiber far-field illumination. HPF’s fiber scrambler is designed to suppress the impact of these illumination changes on the RVs—but the residual impact on the RV measurements has yet to be probed on-sky. We use GJ 411, a bright early type (M2) M dwarf to probe the effects of far-field input trends due to these pupil variations on HPF RVs. These large changes (∼2x) in the pupil area and centroid present a harsh test of HPF’s far-field scrambling. Our results show that the RVs are effectively decoupled from these extreme far-field input changes due to pupil centroid offsets, attesting to the effectiveness of the scrambler design. This experiment allows us to test the impact of these changes with large pupil variation on-sky, something we would not easily be able to do at a conventional optical telescope. While the pupil and illumination changes expected at these other telescopes are small, scaling from our results enables us to estimate and bound these effects, and show that they are controllable even for the new and next generation of RV instruments in their quest to beat down instrumental noise sources toward the goal of a few .
[en] An optical encryption scheme with spatially incoherent illumination based on two micromirror light modulators has been experimentally implemented for the first time. Currently, such modulators are the fastest tools for spatio-temporal light modulation; their high frame rates provide possibilities for developing optical encryption systems with a bandwidth of several gigabites per second. (optical encryption)