Very-High Color Rendering Index Hybrid White Organic Light-Emitting Diodes with Double Emitting Nanolayers

A very-high color rendering index white organic light-emitting diode(WOLED) based on a simple structure was successfully fabricated. The optimized device exhibits a maximum total efficiency of 13.1 and 5.4 lm/W at 1,000 cd/m2. A peak color rendering index of 90 and a relatively stable color during a wide range of luminance were obtained. In addition, it was demonstrated that the 4,40,400-tri(9-carbazoyl) triphenylamine host influenced strongly the performance of this WOLED.These results may be beneficial to the design of both material and device architecture for high-performance WOLED.

Effect of light-emitting diodes with different color rendering indexes on the ocular tissues of rat

AIM:To compare the damage of light-emitting diodes(LEDs)with different color rendering indexes(CRIs)to the ocular surface and retina of rats.METHODS:Totally 20 Sprague-Dawley(SD)rats were randomly divided into four groups:the first group was normal control group without any intervention,other three groups were exposed by LEDs with low(LED-L),medium(LED-M),and high(LED-H)CRI respectively for 12 h a day,continuously for 4 wk.The changes in tear secretion(Schirmer I test,SIt),tear film break-up time(BUT),and corneal fluorescein sodium staining(CFS)scores were compared at different times(1 d before experiment,2 and 4 wk after the experiment).The histopathological changes of rat lacrimal gland and retina were observed at 4 wk,and the expressions of tumor necrosis factor-α(TNF-α)and interleukin-6(IL-6)in lacrimal gland were detected by immunofluorescence method.RESULTS:With the increase of light exposed time,the CFS value of each light exposed group continued to increase,and the BUT and SIt scores continued to decrease,which were different from the control group,and the differences between the light exposed groups were statistically significant.Hematoxylin-eosin(HE)results showed that the lacrimal glands of each exposed group were seen varying degrees of acinar atrophy,vacuoledistribution,increasing of eosinophil granules,etc.;the retina showed obvious reduction of photoreceptor cell layer and changes in retinal thickness;LED-L group has the most significant change in all tests.Immunofluorescence suggested that the positive expressions of TNF-αand IL-6 in the lacrimal glands of each exposed group were higher than those of the control group.CONCLUSION:LED exposure for 4 wk can cause the pathological changes of lacrimal gland and retina of rats,and increase the expression of TNF-αand IL-6 in lacrimal gland,the degree of damage is negatively correlated with the CRI.

High color rendering index white organic light-emitting diode using levofloxacin as blue emitter

Levofloxacin （LOFX）, which is well-known as an antibiotic medicament, was shown to be useful as a 452-nm blue emitter for white organic light-emitting diodes （OLEDs）. In this paper, the fabricated white OLED contains a 452-nm blue emitting layer （thickness of 30 nm） with 1 wt% LOFX doped in CBP （4,4＇-bis（carbazol-9-yl）biphenyl） host and a 584-nm orange emitting layer （thickness of 10 nm） with 0.8 wt% DCJTB （4-（dicyanomethylene）-2-tert-butyl-6-（1,1,7,7- tetramethyljulolidin-4-yl-vinyl）-4H-pyran） doped in CBE which are separated by a 20-nm-thick buffer layer of TPBi （2,2＇,2＂-（benzene-1,3,5-triyl）-tri（1-phenyl-lH-benzimidazole）. A high color rendering index （CRI） of 84.5 and CIE chromaticity coordinates of （0.33, 0.32）, which is close to ideal white emission CIE （0.333, 0.333）, are obtained at a bias voltage of 14 V. Taking into account that LOFX is less expensive and the synthesis and purification technologies of LOFX are mature, these results indicate that blue fluorescence emitting LOFX is useful for applications to white OLEDs although the maximum current efficiency and luminance are not high. The present paper is expected to become a milestone to using medical drug materials for OLEDs.

High efficient and high color rendering index white organic light-emitting diodes

We have fabricated high-efficient white organic light-emitting diodes （WOLEDs） using two types of electron transport materials with different electron mobility. The effect of the electron mobility on the device performance is discussed. In addition, to generate the desired white emission and high color rendering index, we perform the structure design of OLED, in which the functions of co-host of blue and green dopants on chromatic-stability are investigated. Experimental results find that the maximum color rendering index reaches as high as 91 at the voltage of 8 V.

Fabrication of High Color Rendering Index White Light Emitting Diodes from Gold Nanoclusters

We demonstrated gold nanoclusters as color tunable emissive light converters for the application of white light emitting diodes (WLEDs). A blue LED providing 460 nm to excite gold nanoclusters mixed with UV curable material generates broad bandwidth emission at the visible range. Increasing the amount of gold nanoclusters, the correlated color temperature of WLEDs tuned from cold white to warm white, and also results in the variation of color rendering index (CRI). The highest CRI in the experiment is 92.

Early Cretaceous Climate Changes Recorded in Magnetic Susceptibility and Color Index Variations of the Lower Liupanshan Group, Central China

This study carried out comprehensive analysis on sedimentology, magnetic susceptibility （7of） and color data of the continental sediments of the Liupanshan Group in Central China so as to obtain climatic change information during the 129.14-122.98 Ma interval. Based on the results of the Xlf and of the redness （a＊）, the section can be divided into two segments： （1） 129.14-126.3 Ma, with the lowest Xlf values and strongly variable relatively high values of redness and （2） 126.3-122.98 Ma, with high Elf values and relatively low redness. Analysis of the lithology and facies as well as the magnetic minerals and their contents points to a detrital origin of the magnetic minerals and this allow us to interpret the relationship between magnetic susceptibility variations and climate changes. Our study shows that the climate was significantly dry and hot during the whole studied interval although the interval between 126.3 Ma and 122.98 was a little bit cooler with increased humidity.

Characterization and color rendering enhancement of some LEDs for photometric application

The new standards for the photometric characterization of light-emitting diode(LED)sources and luminaries require the measurement evaluation of photometric and colorimetric quantities.This present work studies the performance of some types of LED light sources in different spectra and different color temperature for photometric and colorimetric applications.The study depends on mixed spectra of these different types of LEDs to enhance the color rendering index(CRI)to be near as possible to standard sources.Characterization of LED sources requires the evaluation of some photometric and colorimetric quantities such as luminous flux(),chromaticity coordinates(x,y)and(u′,v′),correlated color temperature(CCT)and color rending indices(CRI).

Image Color Rendering Based on Hinge-Cross-Entropy GAN in Internet of Medical Things

Computer-aided diagnosis based on image color rendering promotes medical image analysis and doctor-patient communication by highlighting important information of medical diagnosis.To overcome the limitations of the color rendering method based on deep learning,such as poor model stability,poor rendering quality,fuzzy boundaries and crossed color boundaries,we propose a novel hinge-cross-entropy generative adversarial network(HCEGAN).The self-attention mechanism was added and improved to focus on the important information of the image.And the hinge-cross-entropy loss function was used to stabilize the training process of GAN models.In this study,we implement the HCEGAN model for image color rendering based on DIV2K and COCO datasets,and evaluate the results using SSIM and PSNR.The experimental results show that the proposed HCEGAN automatically re-renders images,significantly improves the quality of color rendering and greatly improves the stability of prior GAN models.

Color Correction for Multi-view Video Using Energy Minimization of View Networks

Systems using numerous cameras are emerging in many fields due to their ease of production and reduced cost, and one of the fields where they are expected to be used more actively in the near future is in image-based rendering （IBR）. Color correction between views is necessary to use multi-view systems in IBR to make audiences feel comfortable when views are switched or when a free viewpoint video is displayed. Color correction usually involves two steps： the first is to adjust camera parameters such as gain, brightness, and aperture before capture, and the second is to modify captured videos through image processing. This paper deals with the latter, which does not need a color pattern board. The proposed method uses scale invariant feature transform （SIFT） to detect correspondences, treats RGB channels independently, calculates lookup tables with an energy-minimization approach, and corrects captured video with these tables. The experimental results reveal that this approach works well.

The Study of Ovarian Artery Hemodynamics in Patients with Infertility by Color Doppler Energy

Seventy four cases of infertility were examined to study the hemodynamics of the bilateral ovarian arteries at 21st day during the corpus luteum phase by color Doppler energy(CDE) and color Doppler flow imaging (CDFI). All the patients were verified by laparoscopy, fallopian tube patency examination and ovarian function test. Twenty two healthy women served as controls. The results showed that the difference of resistance index(RI)and pulsatility index (PI) of bilateral ovarian arteries between the infertility and the normal controls had statistical significance ( P <0.01), and the PI showed negative correlation with the thickness of endometrium (left side: r =0.724, P <0.01; right side: r =0.756, P <0.01). The results also showed that CDE was more sensitive than CDFI in displaying the ovarian arteries. It could be concluded that the elevated resistance of ovarian artery during the corpus luteum phase was one of the important factors that resulted in infertility.

Diagnostic value of different color ultrasound diagnostic method in endometrial lesions

BACKGROUND Endometrial lesions include endometrial cancer and inferior fibroids.Among them,endometrial cancer as a malignant tumor seriously endangers the life and health of patients.Ultrasonography is an important means of diagnosing female reproductive system diseases,and it is of critical value for the early diagnosis of endometrial cancer.However,different ultrasound inspection programs have achieved different results.It is of great significance to choose a suitable inspection program.AIM To explore the diagnostic efficacy of different ultrasonic examination methods in clinical endometrial lesions.METHODS The 140 patients with endometrial lesions who were treated in our hospital from April 2018 to October 2019 were used as the research subjects.All patients underwent transvaginal color ultrasound and transabdominal color ultrasound.We compared the diagnostic coincidence and image display effects of the two different examination methods,and the endometrial thickness,blood flow,uterine effusion and resistance index of different diseases were observed by transvaginal color ultrasound.RESULTS The diagnostic coincidence rate of all types of diseases of transvaginal color ultrasound was significantly higher than that of transabdominal color ultrasound(P=0.001,0.005,0.001 and 0.001).In addition,the excellent and good rate of image display of transvaginal color ultrasound was higher than that of transabdominal color ultrasound(P=0.001).There were significant differences in endometrial thickness in patients with different types of endometrial lesions through the transvaginal color examination(P=0.001).The incidence rate of uterine effusion in patients with endometrial carcinoma was significantly higher than that in patients with other types of endometrial lesions(P=0.001),and the rate of the blood flow was the highest(P=0.001).The comparison of blood flow resistance index indicated that the blood flow resistance index in endometrial cancer patients was the lowest,which shows that the difference was statistically significant(P=0.001).CONCLUSION The overall diagnostic efficacy of transvaginal color ultrasound in the clinical diagnosis of endometrial lesions is better than that of transabdominal color ultrasound,which held higher diagnostic coincidence rate and image display effect.There were significant differences in the thickness of the endometrium and the blood flow in different types of lesions.

Correlation Study of Color Doppler Examination of Deep Veins of Both Lower Extremities Combined with Fibrinolysis System in Hypertension during Pregnancy

Objective: To investigate the correlation between deep static color Doppler ultrasound of both lower extremities combined with fibrinolytic system detection in pregnancy-induced hypertension. Methods: A total of 70 normal pregnant women, 70 pregnant women with hypertension during pregnancy, and 50 healthy non-pregnant women in the same period were selected as the research objects. The deep veins of both lower limbs were examined by Rili Erlangshen’s color Doppler ultrasound diagnostic instrument (CDU), and the fibrinolysis system was tested by enzyme-linked immunosorbent assay (ELISA) method and automatic hemagglutination analyzer. Results: Compared with the non-pregnant group, the inner diameters of the left/right femoral vein (CFV) and popliteal vein (POV) in the normal pregnancy group and the pregnancy-induced hypertension group were significantly widened, and the peak blood flow spectrum was significantly reduced. The difference was statistically significant (P < 0.01);FIB, PLG, t-PA, PAI, D-Dimer were significantly increased, the difference was statistically significant (P < 0.01);Compared with the normal pregnancy group, the inner diameter of the left/right femoral vein (CFV) in the hypertensive pregnancy group was significantly wider than that in the normal pregnancy group, and the peak value of the left/right POV blood flow spectrum was significantly lower than that in the normal pregnancy group, the difference was statistically significant (P < 0.01), while the left/right popliteal vein (POV) inner diameter, left/right CFV blood flow peak value did not change significantly from the normal pregnancy group, and the difference was not statistically significant (P > 0.05);FIB, PLG, PAI, D-Dimer of the hypertensive disease group during pregnancy significantly increased, the difference was statistically significant (P < 0.01), while t-PA was not statistically significant (P > 0.05). Conclusion: Normal pregnant women have a hypercoagulable state compared with healthy non-pregnant women, and pregnant women with hypertension during pregnancy are more likely to be in a pre-thrombotic state than pregnant women with normal pregnancy. Deep vein CDU examination of both lower extremities combined with blood fibrinolysis monitoring is of great value in the prevention and treatment of hypertension during pregnancy.

Non-Photorealistic Rendering in Chinese Painting of Animals

A set of algorithms is proposed in this paper to automatically transform 3D animal models to Chinese painting style. Inspired by real painting process in Chinese painting of animals, we divide the whole rendering process into two parts: borderline stroke making and interior shading. In borderline stroke making process we first find 3D model silhouettes in real-time depending on the viewing direction of a user. After retrieving silhouette information from all model edges, a stroke linking mechanism is applied to link these independent edges into a long stroke. Finally we grow a plain thin silhouette line to a stylus stroke with various widths at each control point and a 2D brush model is combined with it to simulate a Chinese painting stroke. In the interior shading pipeline, three stages are used to convert a Gouraud-shading image to a Chinese painting style image: color quantization, ink diffusion and box filtering. The color quantization stage assigns all pixels in an image into four color levels and each level represents a color layer in a Chinese painting. Ink diffusion stage is used to transfer inks and water between different levels and to grow areas in an irregular way. The box filtering stage blurs sharp borders between different levels to embellish the appearance of final interior shading image. In addition to automatic rendering, an interactive Chinese painting system which is equipped with friendly input devices can be also combined to generate more artistic Chinese painting images manually.

Variable refractive index in environment matte

Environment matting and compositing is a technique to extract a foreground object, including color, opacity, reflec- tive and refractive properties, from a real-world scene, and synthesize new images by placing it into new environments. The description of the captured object is named environment matte. Recent matting and compositing techniques can produce quite realistic images for objects with complex optical properties. This paper presents an approximate method to transform the matte by simulating variation of the foreground object’s refractive index. Our algorithms can deal with achromatous-and-transparent ob- jects and the experimental results are visually acceptable. Our idea and method can be applied to produce some special video effects, which could be very useful in film making, compared with the extreme difficulty of physically changing an object’s refractive index.

Lead-phase and red-stripe color morphs of red-backed salamanders Plethodon cinereus differ in hematological stress indices:A consequence of differential predation pressure?

Throughout the animal kingdom there are species that have two or more phenotypic forms or ‘morphs＇, and many of these are amphibians. In North America, the red-backed salamander Plethodon cinereus can have either a red dorsal stripe or no dorsal stripe （lead-phase form）, and evidence to date indicates the lead-phase form incurs a greater number of attacks from predators. In a recent collection of 51 P cinereus, blood smears of both color morphs （35 red-stripe, 16 lead-phase） were examined to obtain numbers of circulating leukocytes （via light microscopy）, which can be used to indirectly estimate levels of stress hormones in vertebrates via a ‘hematological stress index＇, which is the ratio between the number of two leukocyte types （neutrophils and lymphocytes）. Our results showed that lead-phase salamanders tended to have greater numbers of circulating neutrophils and lower numbers of circulating lymphocytes than red-stripe morphs, leading to higher average neutrophil-lymphocyte ratios in lead-phase individuals. Since the salamanders were held （refrigerated） for 7 days before sampling, we cannot be certain if this effect is a stress reaction to the captivity or the normal level for this morph. However comparison with two sets of related salamanders that were captured and sampled immediately indicates the red-stripe salamanders were either not stressed from the captivity at all, or their white blood cell distributions had returned to normal after 7 days of captivity. Taken together, our results indicate that lead-phase forms of P. cinereus have higher stress levels than the red-stripe forms, which may be a consequence of their higher exposure to, and/or attacks from, predators. They may also indicate that the lead-phase form is less-suited to captivity than the red-stripe form of this species.

Color-converted remote phosphor prototype of a multiwavelength excitable borosilicate glass for white light-emitting diodes

We report a unique red light-emitting Eu-doped borosilicate glass to convert color for warm white light-emitting diodes. This glass can be excited from 394 nm-peaked near ultraviolet light, 466 nm-peaked blue light, to 534 nm- peaked green light to emit the desired red light with an excellent transmission in the wavelength range of 400-700 nm which makes this glass suitable for color conversion without a great cost of luminous power loss. In particular, when assembling this glass for commercial white light-emitting diodes, the tested results show that the color rendering index is improved to 84 with a loss of luminous power by 12 percent at average, making this variety of glass promising for inorganic ＂remote-phosphor＂ color conversion.

A New Fire Detection Method Using a Multi-Expert System Based on Color Dispersion, Similarity and Centroid Motion in Indoor Environment

In this paper, a video fire detection method is proposed, which demonstrated good performance in indoor environment. Three main novel ideas have been introduced. Firstly, a flame color model in RGB and HIS color space is used to extract pre-detected regions instead of traditional motion differential method, as it’s more suitable for fire detection in indoor environment. Secondly, according to the flicker characteristic of the flame, similarity and two main values of centroid motion are proposed. At the same time, a simple but effective method for tracking the same regions in consecutive frames is established. Thirdly,a multi-expert system consisting of color component dispersion,similarity and centroid motion is established to identify flames.The proposed method has been tested on a very large dataset of fire videos acquired both in real indoor environment tests and from the Internet. The experimental results show that the proposed approach achieved a balance between the false positive rate and the false negative rate, and demonstrated a better performance in terms of overall accuracy and F standard with respect to other similar fire detection methods in indoor environment.

COLOR FLOW IMAGING OF HEPATIC CARCINOMA

Color flow imaging(CFI)ultrasound technique can discover the tumor vascularity and superimposed it to convontional B-mode ultrasonogram in real-time. The flow velocity on spectral Doppler sonogram can be measured by setting the sample volume to any selected site.One hundred and thirty-six patients with solid hepatic space-occupied lesions had been admitted and 113 cases were confirmed by operation and pathology,23 patients were strongly suspected by hepatic angiography (HAA).Ninety nine patients with 109 nodules were finally diagnosed as hepatic cellular carcinoma(HCC).According to color flow distribution pattern,3 kinds of color configuation had been nominated.Tumor vascularity discovered by CFI,especially the arterial blood flow was easy to be recognized,and its emerge rate was quite different between HCC group(94.5%)and hemangioma(HCH)group(17.07%)(P<0.01).Spectral Doppler studies were also carried out in these cases and the detectability of arterial flow in HCC group(95.41%)was much higher than that to HCH group (21. 95%) (P<0. 005).Resistant index(RI)and pulsatile index(PI)could be used to differentiate HCC (>0. 50 and >0.80 respectively)from HCH (P<0.001 and P<0.001 respectively).Arterial-portal(A-P) shunt could also be detected by CFI and spectral Doppler(mostly its Vmax>0.6m/s).The detection rate of A-P shunt was 64% in HCC group,but no case could be detected in HCH group.

Color Estimation for Thermal Infrared Imagery Based on Kernel PCA and Sparse Representation

Adding colors to monochrome thermal infrared images can help observers understand the scenery better. A nonlinear color estimation method for single-band thermal infrared imagery based on kernel principal component analysis (KPCA) and sparse representation was proposed. Nonlinear features of infrared image were extracted using KPCA. The relationship between image features and chromatic values was learned using sparse representation and a color estimation model was obtained. The thermal infrared images can be rendered automatically using the color estimation model. The experimental results show that the proposed method can render infrared image with an accurate color appearance. The proposed idea can also be used in other color estimation problem.

Correlated Color Temperature Tunable Multi-chip Light Emitting Diodes Light Source Design

One of the methods to derive white light from light emitting diodes(LEDs)is the multi-chip white LED technology,which mixes the light from red,green and blue LEDs.Introduced is an optimal algorithm for the spectrum design of the multi-chip white LEDs in this paper.It optimizes the selection of single color LEDs and drive current controlling,so that the multi-chip white LED achieves the target correlated color temperature(CCT),as well as high luminous efficacy and good color rendering.A CCT tunable LED light source with four high-power LEDs is realized based on the above optimal design.Test results show that it maintains satisfactory color rendering and stable luminous efficacy across the whole CCT tuning range.Finally,discussed are the design improvement and the prospect of the future applications of the CCT tunable LED light source.