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[IEEE IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Valencia (2018.7.22-2018.7.27)] IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - The Effect of Trunks on Directional Brightness Temperatures of a Leafless Forest Using a Geometrical Optical Model
摘要： In the paper, a geometric optical model is proposed for a vegetation-trunk-soil scene. The effect of tree trunks was analyzed by comparing directional brightness temperatures (BTs) between vegetation-soil and vegetation-trunk-soil scenes. The comparison result reveals the tree trunk can cause directional BTs as a whole lower because of its shadow and shaded area. Therefore, the tree trunk should be considered when retrieving temperatures from thermal infrared observations over a leafless forest. Efforts using measured TIR data requires to be done in the future.
关键词： vegetation-trunk-soil canopy,directional anisotropy,brightness temperature
更新于2025-09-23 15:23:52
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Scattering Effect Contributions to the Directional Canopy Emissivity and Brightness Temperature Based on CE-P and CBT-P Models
摘要： The directional anisotropy of canopy emissivity and brightness temperature in the thermal infrared band has widely been studied. However, the contribution of different scattering orders has been an open scientific question for many years. The recently proposed CE-P model enables us to analytically evaluate the different scattering orders. Herein, we derive expressions for the first double collisions (DCE12) and first triple collisions (DCE123). Our result shows that DCE123 can simulate the observed emissivity with an error less than 0.001 and that DCE12 is reasonably accurate when leaf emissivity is greater than 0.96. Numerical analysis shows that the contribution of quadruple or greater collisions can be ignored when the leaf (soil) emissivity is no less than 0.90. Furthermore, we develop the CBT-P model to simulate the directional brightness temperature (DBT) based on the new optimized CE-P model (DCE123) and validate it by 4SAIL (4-Stream Radiative Transfer Theory of Scattering by Arbitrary Inclined Leaves) and DART (Discrete Anisotropic Radiative Transfer) models. Both of isothermal (soil temperature is equal to leaf temperature) and nonisothermal (soil temperature is higher than leaf temperature) cases are considered. The maximum differences between the CBT-P model and 4SAIL (DART) are less than 0.35 K (0.42 K), the average differences between CBT-P and 4SAIL (DART) are less than 0.10 K (0.13 K), and the R2 is over 0.99 (0.95) with component emissivities larger than 0.90 and the difference between soil and leaf temperatures less than 20 K. The directional anisotropy of DBT is dominated by the zero-scattering and the single scattering terms according to the new developed CBT-P model.
关键词： directional canopy emissivity (DCE),CBT-P,Discrete Anisotropic Radiative Transfer (DART),4-Stream Radiative Transfer Theory of Scattering by Arbitrary Inclined Leaves (4SAIL),CE-P,directional brightness temperature (DBT)
更新于2025-09-23 15:23:52
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Photon Counting - Fundamentals and Applications || Detectors for Super-Resolution & Single-Molecule Fluorescence Microscopies
摘要： The resolution of light microscopy was thought to be limited to 250–300 nanometers based on the work of Ernest Abbe. This Abbe diffraction limit was believed to be insurmountable until the invention of Super-resolution microscopic techniques in the late 20th century. These techniques remove this limit and have provided unprecedented detail of cellular structures and dynamics down to several nanometers. An emerging goal in this field is to quantitatively measure individual molecules. Measurement of single-molecule dynamics, such as diffusion coefficients and complex stoichiometries, can be accomplished using fluorescence fluctuation techniques to reveal nanosecond-to-microsecond temporal reactions. These powerful complimentary experimental approaches are made possible by sensitive low-light photodetectors. In this chapter, an overview of the principles of super-resolution and single-molecule microscopies are provided. The different types of photodetectors employed in these techniques are explained. In addition, the advantages and disadvantages for these detectors are discussed, as well as the development of next generation detectors. Finally, example super-resolution and single-molecule cellular studies that take advantage of these detector technologies are presented.
关键词： biophysical techniques,STORM,nanoscopy,STED,protein dynamics,palm,spectroscopy,molecular brightness,fluorescence fluctuation
更新于2025-09-23 15:23:52
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Facial Skin Lifting and Brightening Following Sleep on Copper Oxide Containing Pillowcases
摘要： Copper plays a key role in many of the physiological processes that occur in the skin. Previously it was found that sleeping on pillowcases impregnated with microscopic copper oxide particles results in reduction of wrinkles and ?ne lines. In the current study, it was examined if sleeping on copper oxide impregnated pillowcases results also in skin lifting and skin brightness. A four week, double blind, randomized study was performed, during which 45 women, aged 37–54, slept on copper oxide containing pillowcases (test group, n = 23) or on control pillowcases without copper oxide (control group, n = 22). Facial and eye skin surface was measured using an F-ray 3D measurement system and surface analysis was conducted using Image-pro? plus. Skin brightness was measured using a tristimulus colorimeter. Sleeping on the test pillowcases resulted in statistically signi?cant skin lifting on the cheek area (p = 0.039) and eye area (p = 0.001) after four weeks of use as compared to baseline. The mean skin brightness in those sleeping on the test pillowcases increased after two (p = 0.024) and four weeks (p = 0.008). No statistically signi?cant changes occurred during the study in the study participants using the control pillowcases. Statistically signi?cant differences between both groups were recorded at two and four weeks for skin brightness and skin lifting, respectively. In conclusion, sleeping on copper oxide containing pillowcases results in facial skin lifting and brightness of the skin.
关键词： lifting,clinical study,copper oxide,pillowcases,skin,brightness
更新于2025-09-23 15:23:52
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UHD 3D medical system of small‐ and medium‐sized monitor
摘要： With the development of ultra-high definition (UHD) display technology and stereoscopic 3D display technology, 3D ultra-high monitor will help surgeons obtain the spatial hierarchy of internal tissues, identify tissue surfaces and blood vessels clearly, locate the focus precisely and reduce surgery time. Compared with normal 2D medical monitors, 3D medical monitors will lose more brightness because of the 3D application, so it is necessary to design a high-brightness backlight system to guarantee the display stability and the accuracy of the diagnosis. This paper presents a novel processing system for 4K UHD 3D medical monitor with the architecture combined with universal SOC (system on a chip) and specialized FPGA (field programmable gate array). A hardware system is designed with high efficiency and reliable brightness stability control for small- and medium-sized monitors. Furthermore, we analyze the two dimming modes of linear dimming and PWM dimming for a better application in medical monitor.
关键词： medical monitor,PWM dimming,3D,linear dimming,brightness stability
更新于2025-09-23 15:22:29
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Coulomb interaction-induced jitter amplification in RF-compressed high-brightness electron source ultrafast electron diffraction
摘要： We have theoretically and experimentally demonstrated an RF compression-based jitter-amplification effect in high-brightness electron source ultrafast electron diffraction (UED), which degrades the temporal resolution significantly. A detailed analysis and simulations reveal the crucial role of the longitudinal and transverse Coulomb interaction for this jitter-amplification effect, which accord very well with experimental results. An optimized compact UED structure for full compression has been proposed, which can suppress the jitter by half and improve the temporal resolution to sub-100 fs. This Coulomb interaction-induced jitter amplification exists in nearly the whole ultrafast physics field where laser-electron synchronization is required. Moreover, it cannot be suppressed completely. The quantified explanation for the mechanism and optimization provides important guidance for photocathode accelerators and other compression-based ultrashort electron pulse generation and precise control.
关键词： system optimization,jitter amplification,RF compression,high-brightness electron source,ultrafast electron diffraction,Coulomb interaction
更新于2025-09-23 15:21:21
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Streamlining volumetric multi-channel image cytometry using hue-saturation-brightness-based surface creation
摘要： Image cytometry is the process of converting image data to flow cytometry-style plots, and it usually requires computer-aided surface creation to extract out statistics for cells or structures. One way of dealing with structures stained with multiple markers in three-dimensional images, is carrying out multiple rounds of channel co-localization and image masking before surface creation, which is cumbersome and laborious. We propose the application of the hue-saturation-brightness color space to streamline this process, which produces complete surfaces, and allows the user to have a global view of the data before flexibly defining cell subsets. Spectral compensation can also be performed after surface creation to accurately resolve different signals. We demonstrate the utility of this workflow in static and dynamic imaging datasets of a needlestick injury on the mouse ear, and we believe this scalable and intuitive approach will improve the ease of performing histocytometry on biological samples.
关键词： spectral compensation,image cytometry,surface creation,hue-saturation-brightness,histocytometry
更新于2025-09-23 15:21:21
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[IEEE 2018 31st International Vacuum Nanoelectronics Conference (IVNC) - Kyoto, Japan (2018.7.9-2018.7.13)] 2018 31st International Vacuum Nanoelectronics Conference (IVNC) - Properties of one-free standing CNT cold cathode for high resolution devices
摘要： A high resolution imaging technology has been developed with cold cathode electron source. Just grown carbon nanotube (CNT) field emitter was prepared for electron microscope. The angular current density, virtual source and lifetime of the emitted electrons were evaluated with three different categorized. An estimated beam brightness was extracted from the experimental value. With the geometric field enhancement factor, reduced brightness (Br) is depend on and enhanced brightness with higher geometric factors. The reduced brightness of 1.42 × 1011 A · m-2sr-1V-1 at 1,100V of applied voltage obtained.
关键词： CNT cold cathode,High brightness,Electron microscopy
更新于2025-09-23 15:21:21
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Chromophores in cellulosics, XVIII. Degradation of the cellulosic key chromophore 5,8-dihydroxy-[1,4]-naphthoquinone under conditions of chlorine dioxide pulp bleaching: a combined experimental and theoretical study
摘要： DHNQ is one of the key chromophores occurring in all types of aged cellulosics. This study investigates the degradation of DHNQ by chlorine dioxide at moderately acidic (pH 3) conditions, corresponding to the conditions of industrial bleaching ("D stage"). The degradation involves three major pathways. As initial reaction, a hydrogen transfer from DHNQ to chlorine dioxide via a PCET mechanism occurs to form a radical DHNQ(cid:2) and chlorous acid. DHNQ(cid:2) is then attacked by water to give a pentahydroxynaphthalene radical PHN(cid:2) that is stabilized by strong delocalization of the non-paired electron into its aromatic ring. PHN(cid:2) immediately disproportionates to give the observable intermediate 1,2,4,5,8-pentahydroxynapththalene (I), which was comprehensively con?rmed by NMR and MS (path A). In the presence of excess ClO2, I is immediately further oxidized into acetic acid, glycolic acid, oxalic acid and CO2 as the ?nal, stable, and non-colored products (path C). In the absence of excess ClO2, elimination of water from I regenerates DHNQ (path B), so that at roughly equimolar DHNQ/ClO2 ratios ClO2 is fully consumed while a major part of DHNQ is recovered. To avoid such DHNQ "recycling" under ClO2 consumption—and to completely degrade DHNQ to colorless degradation products instead—ClO2 must be applied in at least ?vefold molar excess relative to DHNQ.
关键词： Density functional theory (DFT),Ab initio calculations,Yellowing,Cellulose,Brightness,Chromophores,5,8-dihydroxy-[1,4]-naphthoquinone,Chlorine dioxide,Brightness reversion,Pulp bleaching
更新于2025-09-23 15:21:01
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Estimating the relative contribution of streetlights, vehicles, and residential lighting to the urban night sky brightness
摘要： Under stable atmospheric conditions the brightness of the urban sky varies throughout the night following the time course of the anthropogenic emissions of light. Different types of artificial light sources (e.g. streetlights, residential, and vehicle lights) have specific time signatures, and this feature makes it possible to estimate the amount of brightness contributed by each of them. Our approach is based on transforming the time representation of the zenithal night sky brightness into a modal expansion in terms of time signatures of the different sources of light. The modal coefficients, and hence the absolute and relative contributions of each type of source, can be estimated by means of a linear least squares fit. A practical method for determining the time signatures of different contributing sources is also described, based on wide-field time-lapse photometry of the urban nightscape. Our preliminary results suggest that, besides the dominant streetlight contribution, artificial light leaking out of the windows of residential buildings may account for a significant share of the time-varying part of the zenithal night sky brightness at the measurement locations, whilst the contribution of the vehicle lights seems to be significantly smaller.
关键词： streetlights,urban night sky brightness,vehicles,light pollution,time-lapse photometry,residential lighting
更新于2025-09-23 15:21:01