Two-color Systems Research Articles

Do apelo comercial ao pano de fundo da ação

Neste artigo será discutido como a ideia de apelo sensório impulsionou a adoção da cor nos primeiros cinemas, especialmente em face da pressão econômica forjada pelo advento da televisão. Também serão analisadas, de forma sucinta, as primeiras tentativas de colorização (tintagens; viragens; estêncil; sistemas de duas cores, como o Kinemacolor), em cujo seio se encontrava uma disputa tecnológica entre a Europa e os EUA; a resistência dos cineastas ao emprego da cor; o triunfo do Technicolor e sua ruína; o domínio do Eastmancolor. Em seguida, comenta-se a “virada” narrativa que impeliu a função de contar histórias ao cinema, tomando o lugar das atrações como mote principal das produções. Por fim, a passagem da cor de aspecto extrínseco e comercial para função narrativa de “pano de fundo” da ação.

Supervise Method for Acute Lymphoblastic Leukemia Segmentation and Classification

Leukemias are classified as either myelogenous (also called myeloid) or lymphocytic depending on which types of white blood cells are affected. Acute leukemias occur when the bone marrow produces immature white cells, and chronic leukemias occur when the marrow produces mature cells. Acute lymphoblastic leukemia (ALL) is a type of cancer in which the bone marrow makes too many immature lymphocytes (a type of white blood cell). Leukemia may affect red blood cells, white blood cells, and platelets. ALL is most common in childhood, with a peak incidence at 2–5 years of age and another peak in old age. Here is an automatic segmentation technique that uses two-color systems and the clustering algorithm K-means. The proposed approach is evaluated on three public image databases with different characteristics and performance measures: accuracy, speci?city, sensitivity and Kappa index. Segmentation and classification of acute lymphoblastic leukemia can be done by using Supervise Learning Approach. In that hybrid model with color and cluster system will be used.

Photophysics of Coumarin and Carbostyril-Sensitized Luminescent Lanthanide Complexes: Implications for Complex Design in Multiplex Detection.

Luminescent lanthanide (Ln(III)) complexes with coumarin or carbostyril antennae were synthesized and their photophysical properties evaluated using steady-state and time-resolved UV-vis spectroscopy. Ligands bearing distant hydroxycoumarin-derived antennae attached through triazole linkers were modest sensitizers for Eu(III) and Tb(III), whereas ligands with 7-amidocarbostyrils directly linked to the coordination site could reach good quantum yields for multiple Ln(III), including the visible emitters Sm(III) and Dy(III), and the near-infrared emitters Nd(III) and Yb(III). The highest lanthanide-centered luminescence quantum yields were 35% (Tb), 7.9% (Eu), 0.67% (Dy), and 0.18% (Sm). Antennae providing similar luminescence intensities with 2-4 Ln-emitters were identified. Photoredox quenching of the carbostyril antenna excited states was observed for all Eu(III)-complexes and should be sensitizing in the case of Yb(III); the scope of the process extends to Ln(III) for which it has not been seen previously, specifically Dy(III) and Sm(III). The proposed process is supported by photophysical and electrochemical data. A FRET-type mechanism was identified in architectures with both distant and close antennae for all of the Lns. This mechanism seems to be the only sensitizing one at long distance and probably contributes to the sensitization at shorter distances along with the triplet pathway. The complexes were nontoxic to either bacterial or mammalian cells. Complexes of an ester-functionalized ligand were taken up by bacteria in a concentration-dependent manner. Our results suggest that the effects of FRET and photoredox quenching should be taken into consideration when designing luminescent Ln complexes. These results also establish these Ln(III)-complexes for multiplex detection beyond the available two-color systems.

Layer-by-layer assembly of ordered organic–inorganic luminescent film toward sensoring nitrobenzene compound

Luminescent film materials sensitive to pollutions are important to develop new types of optical sensors toward environmental detection. Herein we report organic–inorganic hybrid thin films (TFs) with reversible luminescence response to the volatile nitrobenzene (NB) using layer-by-layer (LBL) assembly of fluorescent brightener CXT and Mg–Al-layered double hydroxide (LDH) nanoparticles. The structural and surface morphology studies show that the TFs are continuous and uniform with stacking order in the normal direction of the substrate. AFM and SEM measurements indicated that the films feature periodic structure with a period of ca. 25nm as well as uniform surface morphology. Moreover, the CXT/LDH TF displays a high luminescent response as a fast colorimetric chemosensor for NB vapor with a low detection limit (4.02ppb), good regeneration and high selectivity. In addition, by combining suitable luminescent building blocks, the films can also be extended to other two-color luminescence systems, which exhibit changes in both luminescence intensity and ratiometric fluorescence upon interaction with NB vapor, suggesting that these films can serve as new types of selective solid luminescent sensor. Therefore, this work supplies a facile LBL strategy for the fabrication of TFs as selective luminescent sensor for the trace detection of NB.

Laser radiation frequency conversion in carbon- and cluster-containing plasma plumes under conditions of single and two-color pumping by pulses with a 10-Hz repetition rate

This work reviews a series of investigations of different plasma plumes using single- and two-color laser systems that emit femtosecond pulses with a 10-Hz repetition rate. Results of investigation of the resonant enhancement of harmonics in tin plasma with the use of two types of pumps are analyzed, and it is shown that the tuning of the wavelengths of harmonics to ion-resonance levels plays an important role in increasing the conversion efficiency to high-order harmonics of the radiation to be converted. Investigations of different carbon-containing plasma media (carbon nanotubes, graphite, carbon aerogel, etc.) exhibit attractive properties of the nonlinear medium of this type for efficient generation of high-order harmonics. The results of the first experiments on the use of nanoparticles produced directly in the course of laser ablation of metals for increasing the efficiency of harmonics generated in this cluster-containing medium are analyzed. It is shown that new approaches realized in these investigations give hope that the nonlinear optical response of plasma media in the far-ultraviolet range can be further increased.

Dynamics of two-color laser systems with spectrally filtered feedback

Two-color laser systems based on a semiconductor laser device and spectrally filtered feedback are studied. By use of a broadband numerical simulator and realistic active-structure optical responses, various two-color lasing configurations are investigated. Five characteristic dynamic regimes are observed and classified as semicoherent, coherent, multimode, chaotic, and multimode chaotic. Practical implications for gigahertz or terahertz signal-generation applications are discussed.

Experimental evaluation of the performance of pulsed two-color laser-ranging systems

Two-color laser-ranging systems can be used to estimate the atmospheric delay by measuring the difference in propagation times between two optical pulses transmitted at different wavelengths. This paper describes horizontal-path ranging experiments that were conducted using flat diffuse targets and cube-corner reflector arrays. Measurements of the timing accuracy of the cross-correlation estimator, atmospheric delay, received pulse shapes, and signal power spectra are presented. The results are in general agreement with theory and indicate that target speckle can be the dominant noise source when the target is small and is located far from the ranging system or when the target consists of a small number of cube-corner reflectors.

Planetary Searches Using Optical Astrometric Interferometers

Detection of planets by virtue of their gravitational perturbations of nearby visible stars generally requires relative astrometric accuracies of ~ 3 × 10−4 arc sec for Jovian planets and ~ 3 × 10−7 arc sec for terrestrial planets. Two-color optical astrometric interferometers on earth should be capable of ~ 10−4 arc sec rms accuracy for stars brighter than magnitude 7–10, while small one-color space systems should achieve at least ~ 10−5 arc sec. Two-color systems permit correction every few milliseconds for the random wavefront tilt due to atmospheric turbulence; the correction is based on the observed offset between the red and blue fringes, and the known atmospheric dispersion. A 3.4-meter baseline interferometer on Mount Wilson has demonstrated ~ 0.02 arc sec rms fluctuations for 1-second samples.