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Predicting Hepatocellular Carcinoma Using Brightness Change Curves Derived From Contrast-enhanced Ultrasound Images
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作者 CHEN Ying-Ying JIANG Shang-Lin +3 位作者 HUANG Liang-Hui ZENG Ya-Guang WANG Xue-Hua ZHENG Wei 《生物化学与生物物理进展》 北大核心 2025年第8期2163-2172,共10页
Objective Primary liver cancer,predominantly hepatocellular carcinoma(HCC),is a significant global health issue,ranking as the sixth most diagnosed cancer and the third leading cause of cancer-related mortality.Accura... Objective Primary liver cancer,predominantly hepatocellular carcinoma(HCC),is a significant global health issue,ranking as the sixth most diagnosed cancer and the third leading cause of cancer-related mortality.Accurate and early diagnosis of HCC is crucial for effective treatment,as HCC and non-HCC malignancies like intrahepatic cholangiocarcinoma(ICC)exhibit different prognoses and treatment responses.Traditional diagnostic methods,including liver biopsy and contrast-enhanced ultrasound(CEUS),face limitations in applicability and objectivity.The primary objective of this study was to develop an advanced,lightweighted classification network capable of distinguishing HCC from other non-HCC malignancies by leveraging the automatic analysis of brightness changes in CEUS images.The ultimate goal was to create a user-friendly and cost-efficient computer-aided diagnostic tool that could assist radiologists in making more accurate and efficient clinical decisions.Methods This retrospective study encompassed a total of 161 patients,comprising 131 diagnosed with HCC and 30 with non-HCC malignancies.To achieve accurate tumor detection,the YOLOX network was employed to identify the region of interest(ROI)on both B-mode ultrasound and CEUS images.A custom-developed algorithm was then utilized to extract brightness change curves from the tumor and adjacent liver parenchyma regions within the CEUS images.These curves provided critical data for the subsequent analysis and classification process.To analyze the extracted brightness change curves and classify the malignancies,we developed and compared several models.These included one-dimensional convolutional neural networks(1D-ResNet,1D-ConvNeXt,and 1D-CNN),as well as traditional machine-learning methods such as support vector machine(SVM),ensemble learning(EL),k-nearest neighbor(KNN),and decision tree(DT).The diagnostic performance of each method in distinguishing HCC from non-HCC malignancies was rigorously evaluated using four key metrics:area under the receiver operating characteristic(AUC),accuracy(ACC),sensitivity(SE),and specificity(SP).Results The evaluation of the machine-learning methods revealed AUC values of 0.70 for SVM,0.56 for ensemble learning,0.63 for KNN,and 0.72 for the decision tree.These results indicated moderate to fair performance in classifying the malignancies based on the brightness change curves.In contrast,the deep learning models demonstrated significantly higher AUCs,with 1D-ResNet achieving an AUC of 0.72,1D-ConvNeXt reaching 0.82,and 1D-CNN obtaining the highest AUC of 0.84.Moreover,under the five-fold cross-validation scheme,the 1D-CNN model outperformed other models in both accuracy and specificity.Specifically,it achieved accuracy improvements of 3.8%to 10.0%and specificity enhancements of 6.6%to 43.3%over competing approaches.The superior performance of the 1D-CNN model highlighted its potential as a powerful tool for accurate classification.Conclusion The 1D-CNN model proved to be the most effective in differentiating HCC from non-HCC malignancies,surpassing both traditional machine-learning methods and other deep learning models.This study successfully developed a user-friendly and cost-efficient computer-aided diagnostic solution that would significantly enhances radiologists’diagnostic capabilities.By improving the accuracy and efficiency of clinical decision-making,this tool has the potential to positively impact patient care and outcomes.Future work may focus on further refining the model and exploring its integration with multimodal ultrasound data to maximize its accuracy and applicability. 展开更多
关键词 computer-aided diagnostic deep learning hepatocellular carcinoma contrast-enhanced ultrasound brightness change curve
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The strategy to improve the brightness of organic small-molecule fluorescent dyes for imaging
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作者 Junliang Zhou Tian-Bing Ren Lin Yuan 《Chinese Chemical Letters》 2025年第8期179-189,共11页
Organic small molecule fluorophores have been widely used in biology and biochemistry to study cellular structures and processes at high spatial and temporal resolution.Small-molecule dyes offer various benefits,such ... Organic small molecule fluorophores have been widely used in biology and biochemistry to study cellular structures and processes at high spatial and temporal resolution.Small-molecule dyes offer various benefits,such as high photostability,low molecular weight,and great biocompatibility.However,the poor brightness of most of conventional dyes in biological environments limits their use in high-quality superresolution fluorescence imaging.Chemists have conceived and developed many methods to enhance the brightness of fluorophores,including structural alterations that raise extinction coefficients and quantum yields.This review outlines current attempts and substantial advances achieved by chemists to improve the brightness of organic small-molecule fluorescent dyes,such as scaffold rigidification and twisted intramolecular charge transfer(TICT)inhibition.We think that this review will help researchers understand the chemical mechanisms involved in increasing the brightness of fluorophores for biological applications. 展开更多
关键词 Small-molecule fluorescent dyes brightness Fluorescence quantum yield TICT Structure modification
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Design of Fresnel lens for autostereoscopic 3D display with optimized crosstalk and brightness uniformity
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作者 LAI Liping GAo Lizhen +1 位作者 LIU Kang XU Zhankun 《Optoelectronics Letters》 2025年第11期655-660,共6页
At present,the naked-eye three-dimensional(3D)display technology still has some drawbacks,such as low brightness uniformity,high crosstalk,low light efficiency,short viewing distance,and the manufacturing is difficult... At present,the naked-eye three-dimensional(3D)display technology still has some drawbacks,such as low brightness uniformity,high crosstalk,low light efficiency,short viewing distance,and the manufacturing is difficulty.Based on the principle of naked-eye 3D display and the Fresnel optical theory,this paper designs a Fresnel lens array and the star-shaped liquid crystal display(LCD)switch of unit LCD screen to achieve low-crosstalk and high brightness uniformity for the autostereoscopic 3D display.The unit parameters of a 139.7 cm 4K model autostereoscopic 3D displayer are provided and they are optimized by the TracePro software.The results show that when the pitch of the Fresnel lens on the exit surface is 0.304 mm,the width of each serration of Fresnel lens is 0.0234 mm,the length of the Fresnel lens is 2.87 mm,and the center height of star-shaped LCD switch is 0.030 mm,the center length is 0.040 mm,the width of star-shaped LCD switch is 0.050 mm,and the image crosstalk is less than 2%when the viewing distance is 2.50 m.The problem on the brightness of the image in different positions is improved. 展开更多
关键词 naked eye D display fresnel optical theorythis d display fresnel lens array star shaped LCD switch Fresnel lens brightness uniformity CROSSTALK
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High Brightness,High Power Density Fiber Coupling of High Power Laser Diode
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作者 王晓薇 肖建伟 +5 位作者 王仲明 马骁宇 刘宗顺 方高瞻 张敬明 冯小明 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2001年第9期1112-1115,共4页
The output radiation from the 100μm×1μm aperture of a high power Laser Diode (LD) is efficiently coupled into a 50μm multimode optical fiber.The fiber output of the high power LD with high brightness and high ... The output radiation from the 100μm×1μm aperture of a high power Laser Diode (LD) is efficiently coupled into a 50μm multimode optical fiber.The fiber output of the high power LD with high brightness and high power density is achieved.The power density is up to 3 6×104W/cm2 and the coupling efficiency is 70%.The extreme divergence and the astigmatism of high power LDs require the optics with complex lens structures and high performance.A double-curved lens with two crossed cylindrical lenses structured on both sides of the glass substrate is used in the coupling system. 展开更多
关键词 high power LD double-curved lens fiber coupling high brightness high power density
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氨分解气氛光亮退火对304L不锈钢组织与耐蚀性的影响
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作者 蔡聪 黄兴民 +3 位作者 石宇 韩靖 张娟 杨晓伟 《金属热处理》 北大核心 2026年第2期169-175,共7页
模拟了固溶态304L不锈钢板在800℃氨分解气氛光亮退火过程(1050℃保温15 min缓冷),对其显微组织和耐蚀性能进行表征分析。结果表明:试样表层(距表面约5μm)生成细晶和富铬氮化物,次表层(距表面约40μm)晶界析出富铬碳氮化物,显微硬度分... 模拟了固溶态304L不锈钢板在800℃氨分解气氛光亮退火过程(1050℃保温15 min缓冷),对其显微组织和耐蚀性能进行表征分析。结果表明:试样表层(距表面约5μm)生成细晶和富铬氮化物,次表层(距表面约40μm)晶界析出富铬碳氮化物,显微硬度分别达到(318.0±9.0)HV0.05和(220.9±12.3)HV0.05,超过基体的(187.8±9.2)HV0.05;经硫酸-硫酸铁热浸泡24 h前,表层平均腐蚀速率为0.016 mg/(mm^(2)·h);热浸泡24 h后,不锈钢基体开始发生腐蚀,平均腐蚀速率为0.006 mg/(mm^(2)·h)。残余氨分解产生的氮原子经表面向内并沿晶界扩散,促使表层渗氮和次表层轻微敏化,导致晶间腐蚀倾向提高。 展开更多
关键词 304L不锈钢 氨分解气氛 光亮退火 晶间腐蚀 表层渗氮
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Bright Sparks of Single-Atom and Nano-Islands in Catalysis:Breaking Activity-Stability Trade-Off
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作者 Xinyu Liu Suhua Chen +5 位作者 Shenglian Luo Bo Li Jiajie Wang Gaoxia Zhang Yuqi Zhu Jianping Zou 《Nano-Micro Letters》 2026年第5期181-216,共36页
Single-atom catalysts(SACs)are among the most cutting-edge catalysts in the multiphase catalysis track due to their unique geometrical and electronic properties,the highest atom utilization efficiency,and uniform acti... Single-atom catalysts(SACs)are among the most cutting-edge catalysts in the multiphase catalysis track due to their unique geometrical and electronic properties,the highest atom utilization efficiency,and uniform active sites.SACs have been facing an unresolved problem in practical applications:the opposing contradiction of activity-stability.The successful development of single-atom nano-islands(SANIs)cleverly combines the ultra-high atom utilization efficiency of SACs with the confinement effect and structural stability of nano-island structures,realizing the“moving but not aggregation”of SACs,which fundamentally solves this inherent contradiction.Although research on the precise loading of single atoms on nano-islands continues to advance,existing reviews have not yet established a closed-loop cognitive framework encompassing“models-synthesis-high stability mechanisms-high activity essence-applications.”This work fills this critical gap by systematically integrating the basic conceptual models and cutting-edge synthesis strategies of SANIs,focusing on revealing the underlying mechanisms by which SANIs overcome the stability bottleneck of SACs,elucidating the role of nano-islands and their synergistic mechanisms to clarify the high activity essence,and establishing the structure-activity relationship between atomic confinement effects and macroscopic performance,ultimately achieving breakthrough validation across catalytic systems.This review aims to open new perspectives,drive a paradigm shift in understanding the multi-dimensional advantages of SANIs,and thereby spur breakthrough progress in this frontier field. 展开更多
关键词 Single-atom catalysts Nano-islands Bright sparks Mechanisms Interactions
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向2025年度审稿专家致谢
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《上海口腔医学》 2026年第1期34-34,共1页
2025年度,共有下列63名专家为《上海口腔医学》认真审稿,特提名致谢!(按姓名汉语拼音顺序排列)Many thanks for our peer reviewers,listed below,for their time and hard work spent on review of manuscripts submitted to Shanghai ... 2025年度,共有下列63名专家为《上海口腔医学》认真审稿,特提名致谢!(按姓名汉语拼音顺序排列)Many thanks for our peer reviewers,listed below,for their time and hard work spent on review of manuscripts submitted to Shanghai Journal of Stomatology in 2025 and their excellent support of the editorial process.Sincerely congratulating our authors who have published their high quality work in Shanghai Journal of Stomatology cited by IM and MEDLINE.The future of our journal is bright and it will continue to serve as a top-notch interdisciplinary resources for clinicians involved in the care of patients with various dental disorders,and for scientists striving to elucidate the mechanisms and therapy for these diseases. 展开更多
关键词 bright future editorial process peer review STOMATOLOGY high quality work peer reviewerslisted dental disorders interdisciplinary resources
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Dislocations in motion:engineering mechanoluminescence via pressure-driven phase transitions
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作者 Zhongxiang Wang Tian Liang 《Science China Materials》 2026年第3期1799-1800,共2页
Mechanoluminescent(ML)materials that emit light under mechanical stress are attracting growing attention for their potential in next-generation sensing,display,and energy-harvesting technologies[1].Among these,Mn/Cu-d... Mechanoluminescent(ML)materials that emit light under mechanical stress are attracting growing attention for their potential in next-generation sensing,display,and energy-harvesting technologies[1].Among these,Mn/Cu-doped zinc sulfide(ZnS)has emerged as a leading candidate due to its bright emission,low activation threshold,and remarkable self-recovery over thousands of cycles[2-5]. 展开更多
关键词 MECHANOLUMINESCENCE ZNS dislocations bright emission zinc sulfide zns Mn Cu doped zinc sulfide emit light mechanical stress pressure driven phase transitions
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基于“天明则日月不明”理论探讨肺肠气机失调致结直肠腺瘤癌变机制及防治
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作者 王子涵 王妍颖 +2 位作者 梁可欣 魏红涛 李杨帆 《湖南中医药大学学报》 2026年第1期101-106,共6页
结直肠腺瘤(CRA)为结直肠癌(CRC)的关键癌前病变,其癌变机制与防治策略是中医药防治CRC的重要切入点。本文以《黄帝内经》“天明则日月不明”理论为基础,阐明“明”通“蒙”,喻示肺失清肃如天蒙阴翳,导致大肠传导失职、日月失辉,系统论... 结直肠腺瘤(CRA)为结直肠癌(CRC)的关键癌前病变,其癌变机制与防治策略是中医药防治CRC的重要切入点。本文以《黄帝内经》“天明则日月不明”理论为基础,阐明“明”通“蒙”,喻示肺失清肃如天蒙阴翳,导致大肠传导失职、日月失辉,系统论述肺肠气机失调在CRA癌变中的核心作用。肺气壅滞致肠腑气滞为始动环节,进而湿瘀互结、浊毒内生,最终毒损肠络、癌毒形成,与“肺-肠轴”紊乱、肠道微生态失调、炎症介质累积及免疫抑制等现代病理过程密切相关。本文提出分期防治策略,始动期以宣肺通肠、化滞消癥为主,进展期强调清金化浊、剔络防变,质变期则注重固金伐毒、扶正消癥。基于“天明则日月不明”理论构建“肺肠同治”的防治体系,为阻断CRA癌变提供中医理论依据与临床实践路径,凸显“气机升降”在瘤癌转变防治中的整体调节特色。 展开更多
关键词 结直肠腺瘤 结直肠癌 天明则日月不明 肺肠轴 瘤癌转变
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基于直方图的自适应混合通道先验去雾算法研究
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作者 李旭 莫迪 +1 位作者 邓山景 江先阳 《电子技术应用》 2026年第1期73-77,共5页
大气中的悬浮颗粒物会显著影响阳光的散射。在晴朗的天气里,这些粒子引起的散射相对较弱,所以拍摄出的图像质量较高;但是在雾霾天气下,粒子引起的散射变得严重,拍摄出的图像的质量则会明显下降。然而,清晰的图像对于交通、监控、医疗和... 大气中的悬浮颗粒物会显著影响阳光的散射。在晴朗的天气里,这些粒子引起的散射相对较弱,所以拍摄出的图像质量较高;但是在雾霾天气下,粒子引起的散射变得严重,拍摄出的图像的质量则会明显下降。然而,清晰的图像对于交通、监控、医疗和军事等许多领域的工作的开展有着深刻意义。对于雾天条件下拍摄图像会出现退化的问题,提出了一种基于直方图的自适应混合通道先验(HAHCP)。对大气光值及透射率计算的优化减少了天空区域的halo效应及图像失真的出现。在O-Haze数据集上的实验结果表明,该算法在恢复效果和图像质量方面优于多种传统算法。 展开更多
关键词 去雾 亮通道先验 暗通道先验 直方图统计 自适应融合
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RS-based Analysis of the Correlation between Brightness Temperature and Vegetation Cover—A Case Study of Neijiang City,Sichuan Province of China
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作者 薛万蓉 许辉熙 +2 位作者 但尚铭 何政伟 仇文侠 《Journal of Landscape Research》 2012年第2期35-37,共3页
Landsat TM data(June 23,1988,May 6,2007) and Landsat ETM+data(May 10,2000) of Neijiang City,Sichuan Province was taken as the data source,brightness temperature of the study area was obtained by using TM/ETM+thermal i... Landsat TM data(June 23,1988,May 6,2007) and Landsat ETM+data(May 10,2000) of Neijiang City,Sichuan Province was taken as the data source,brightness temperature of the study area was obtained by using TM/ETM+thermal infrared wave,and also normalized difference vegetation index(NDVI) was calculated.NDVI of the study area on June 23,1988,May 6,2007,and May 10,2000 was respectively obtained by using Band Math,the least square fitting was adopted to simulate the correlation between surface temperature and vegetation cover.Moreover,linear regression analysis of the correlation between vegetation cover and NDVI was carried out in Excel.The results showed that(a) most of the constructed area has a low NDVI value because there are large areas of hard surface such as buildings and roads,but less vegetation cover;(b) the quarters with better vegetation cover have higher NDVI values;the Tuojiang River has a negative NDVI value;rural areas have better vegetation cover and higher NDVI values.Brightness temperature and vegetation cover has distinct negative correlation,specifically,the higher the vegetation cover is,the lower the surface temperature is,and vice versa. 展开更多
关键词 Urban heat ISLAND effects Remote sensing(RS) brightness temperature Normalized difference VEGETATION index(NDVI) CORRELATION ANALYSIS
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Comparative Analysis of Microwave Brightness Temperature Data in Northeast China Using AMSR-E and MWRI Products 被引量:7
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作者 GU Lingjia ZHAO Kai +1 位作者 ZHANG Shuwen ZHANG Shuang 《Chinese Geographical Science》 SCIE CSCD 2011年第1期84-93,共10页
With such significant advantages as all-day observation, penetrability and all-weather coverage, passive mi-crowave remote sensing technique has been widely applied in the research of global environmental change. As t... With such significant advantages as all-day observation, penetrability and all-weather coverage, passive mi-crowave remote sensing technique has been widely applied in the research of global environmental change. As the sat-ellite-based passive microwave remote sensor, the Advanced Microwave Scanning Radiometer-Earth Observing Sys-tem (AMSR-E) loaded on NASA's (National Aeronautics and Space Administration of USA) Aqua satellite has been popularly used in the field of microwave observation. The Microwave Radiation Imager (MWRI) loaded on the Chi-nese FengYun-3A (FY-3A) satellite is an AMSR-E-like conical scanning microwave sensor, but there are few reports about MWRI data. This paper firstly proposed an optimal spatial position matching algorithm from rough to exact for the position matching between AMSR-E and MWRI data, then taking Northeast China as an example, comparatively analyzed the microwave brightness temperature data derived from AMSR-E and MWRI. The results show that when the antenna footprints of the two sensors are filled with either full water, or full land, or mixed land and water with ap-proximate proportion, the errors of brightness temperature between AMSR-E and MWRI are usually in the range from -10 K to +10 K. In general, the residual values of brightness temperature between the two microwave sensors with the same spatial resolution are in the range of ±3 K. Because the spatial resolution of AMSR-E is three times as high as that of MWRI, the results indicate that the quality of MWRI data is better. The research can provide useful information for the MWRI data application and microwave unmixing method in the future. 展开更多
关键词 AMSR-E MWRI FY-3A satellite brightness temperature spatial resolution spatial position matching Northeast China
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Face anti-spoofing algorithm combined with CNN and brightness equalization 被引量:7
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作者 CAI Pei QUAN Hui-min 《Journal of Central South University》 SCIE EI CAS CSCD 2021年第1期194-204,共11页
Face anti-spoofing is a relatively important part of the face recognition system,which has great significance for financial payment and access control systems.Aiming at the problems of unstable face alignment,complex ... Face anti-spoofing is a relatively important part of the face recognition system,which has great significance for financial payment and access control systems.Aiming at the problems of unstable face alignment,complex lighting,and complex structure of face anti-spoofing detection network,a novel method is presented using a combination of convolutional neural network and brightness equalization.Firstly,multi-task convolutional neural network(MTCNN)based on the cascade of three convolutional neural networks(CNNs),P-net,R-net,and O-net are used to achieve accurate positioning of the face,and the detected face bounding box is cropped by a specified multiple,then brightness equalization is adopted to perform brightness compensation on different brightness areas of the face image.Finally,data features are extracted and classification is given by utilizing a 12-layer convolution neural network.Experiments of the proposed algorithm were carried out on CASIA-FASD.The results show that the classification accuracy is relatively high,and the half total error rate(HTER)reaches 1.02%. 展开更多
关键词 face anti-spoofing MTCNN brightness equalization convolutional neural network
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Color-stable,reduced efficiency roll-off hybrid white organic light emitting diodes with ultra high brightness 被引量:4
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作者 刘佰全 陶洪 +4 位作者 苏跃举 高栋雨 兰林锋 邹建华 彭俊彪 《Chinese Physics B》 SCIE EI CAS CSCD 2013年第7期450-453,共4页
High-brightness and color-stable two-wavelength hybrid white organic light emitting diodes (HWOLEDs) with the configuration of indium tin oxide (ITO)/ N, N, N, N-tetrakis(4-methoxyphenyl)-benzidine (MeO-TPD):... High-brightness and color-stable two-wavelength hybrid white organic light emitting diodes (HWOLEDs) with the configuration of indium tin oxide (ITO)/ N, N, N, N-tetrakis(4-methoxyphenyl)-benzidine (MeO-TPD): tetrafluoro-tetracyanoqino dimethane (F4-TCNQ)/N,N-di(naphthalene-1-yl)-N,N-diphenyl-benzidine (NPB)/ 4,4-N,N-dicarbazolebiphenyl (CBP): iridium (III) diazine complexes (MPPZ) 2 Ir(acac)/NPB/2-methyl-9,10-di(2-naphthyl)anthracene (MADN): p-bis(p-N,N-di-phenyl-aminostyryl)benzene (DSA-ph)/bis(10-hydroxybenzo[h] quino-linato)beryllium complex (Bebq2)/LiF/Al have been fabricated and characterized. The optimal brightness of the device is 69932 cd/m2 at a voltage of 13 V, and the Commission Internationale de l’Eclairage (CIE) chromaticity coordinates are almost constant during a large voltage change of 6–12 V. Furthermore, a current efficiency of 15.3 cd/A at an illumination-relevant brightness of 1000 cd/m2 is obtained, which rolls off slightly to 13.0 cd/A at an ultra high brightness of 50000 cd/m2. We attribute this great performance to wisely selecting an appropriate spacer together with effectively utilizing the combinations of exciton-harvested orange-phosphorescence/blue-fluorescence in the device. Undoubtedly, this is one of the most exciting results in two-wavelength HWOLEDs up to now. 展开更多
关键词 white light color stability efficiency roll-off high brightness
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Increase of brightness and transmission efficiency in fiat panel display through serial synchronous scanning mode with double buffers 被引量:4
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作者 陈章进 陈峰 +2 位作者 冉峰 徐美华 郑方 《Journal of Shanghai University(English Edition)》 CAS 2007年第3期314-317,共4页
This paper presents a serial synchronous scanning mode in fiat panel display (FPD) by adding a latch buffer between the serializer and the driving buffer. Comparing with conventional techniques, the proposed structu... This paper presents a serial synchronous scanning mode in fiat panel display (FPD) by adding a latch buffer between the serializer and the driving buffer. Comparing with conventional techniques, the proposed structure can efficiently reduce the brightness loss and improve the transmission performance. Theoretical analysis and experimental results show that the ratio between the lightest weight display time and the relative transmission time is a tradeoff between brightness loss and transmission efficiency. 展开更多
关键词 fiat panel display (FPD) serial scanning double buffer brightness loss transmission utilization
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MODIS BRIGHTNESS TEMPERATURE DATA ASSIMILATION UNDER CLOUDY CONDITIONS: METHODS AND IDEAL TESTS 被引量:5
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作者 丁伟钰 万齐林 +2 位作者 张诚忠 陈子通 黄燕燕 《Journal of Tropical Meteorology》 SCIE 2010年第4期313-324,共12页
Clouds have important effects on the infi'ared radiances transmission in that the inclusion of cloud effects in data assimilation can not only improve the quality of the assimilated atmospheric parameters greatly, bu... Clouds have important effects on the infi'ared radiances transmission in that the inclusion of cloud effects in data assimilation can not only improve the quality of the assimilated atmospheric parameters greatly, but also minimize the initial error of cloud parameters by adjusting part of the infrared radiances data. On the basis of the Grapes-3D-var (Global and Regional Assimilation and Prediction Enhanced System), cloud liquid water, cloud ice water and cloud cover are added as the governing variables in the assimilation. Under the conditions of clear sky, partly cloudy cover and totally cloudy cover, the brightness temperature of 16 MODIS channels are assimilated respectively in ideal tests. Results show that when the simulated background brightness temperatures are lower than the observation, the analyzed field will increase the simulated brightness temperature by increasing its temperature and reducing its moisture, cloud liquid water, cloud ice water, and cloud cover. The simulated brightness temperature can be reduced if adjustment is made in the contrary direction. The adjustment of the temperature and specific humidity under the clear sky conditions conforms well to the design of MODIS channels, but it is weakened for levels under cloud layers. The ideal tests demonstrate that by simultaneously adding both cloud parameters and atmospheric parameters as governing variables during the assimilation of infrared radiances, both the cloud parameters and atmospheric parameters can be adjusted using the observed infrared radiances and conventional meteorological elements to make full use of the infrared observations. 展开更多
关键词 cloud parameters MODIS brightness temperature data ASSIMILATION
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Cross-calibration of brightness temperature obtained by FY-3B/MWRI using Aqua/AMSR-E data for snow depth retrieval in the Arctic 被引量:3
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作者 Haihua Chen Lele Li Lei Guan 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2021年第1期43-53,共11页
This study cross-calibrated the brightness temperatures observed in the Arctic by using the FY-3B/MWRI L1 and the Aqua/AMSR-E L2A.The monthly parameters of the cross-calibration were determined and evaluated using rob... This study cross-calibrated the brightness temperatures observed in the Arctic by using the FY-3B/MWRI L1 and the Aqua/AMSR-E L2A.The monthly parameters of the cross-calibration were determined and evaluated using robust linear regression.The snow depth in case of seasonal ice was calculated by using parameters of the crosscalibration of data from the MWRI Tb.The correlation coefficients of the H/V polarization among all channels Tb of the two sensors were higher than 0.97.The parameters of the monthly cross-calibration were useful for the snow depth retrieval using the MWRI.Data from the MWRI Tb were cross-calibrated to the AMSR-E baseline.Biases in the data of the two sensors were optimized to approximately 0 K through the cross-calibration,the standard deviations decreased significantly in the range of 1.32 K to 2.57 K,and the correlation coefficients were as high as 99%.An analysis of the statistical distributions of the histograms before and after cross-calibration indicated that the FY-3B/MWRI Tb data had been well calibrated.Furthermore,the results of the cross-calibration were evaluated by data on the daily average Tb at 18.7 GHz,23.8 GHz,and 36.5 GHz(V polarization),and at 89 GHz(H/V polarization),and were applied to the snow depths retrieval in the Arctic.The parameters of monthly cross-calibration were found to be effective in terms of correcting the daily average Tb.The results of the snow depths were compared with those of the calibrated MWRI and AMSR-E products.Biases of 0.18 cm to 0.38 cm were observed in the monthly snow depths,with the standard deviations ranging from 4.19 cm to 4.80 cm. 展开更多
关键词 FY-3B AMSR-E brightness temperature(T^(b)) CROSS-CALIBRATION snow depth ARCTIC
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Verification and recalibration of HY-2A microwave radiometer brightness temperature 被引量:2
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作者 ZHAO Yili LI Huimin +1 位作者 CHEN Chuntao ZHU Jianhua 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2019年第3期968-981,共14页
HY-2A is the first one of the Chinese HY-2 ocean satellite series carrying a microwave radiometer(RM)to measure sea surface temperature,sea surface wind speed,atmospheric water vapor,cloud liquid water content,and rai... HY-2A is the first one of the Chinese HY-2 ocean satellite series carrying a microwave radiometer(RM)to measure sea surface temperature,sea surface wind speed,atmospheric water vapor,cloud liquid water content,and rain rate.We verified the RM level 1B brightness temperature(T B)to retrieve environmental parameters.In the verification,TB that simulated using the ocean-atmosphere radiative transfer model(RTM)was used as a reference.The total bias and total standard deviation(SD)of the RM level 1B TB,with reference to the RTM simulation,ranged-20.6-4.38 K and 0.7-2.93 K,respectively.We found that both the total bias and the total SD depend on the frequency and polarization,although the values for ascending and descending passes are different.In addition,substantial seasonal variation of the bias was found at all channels.The verification results indicate the RM has some problems regarding calibration,e.g.,correction of antenna spillover and antenna physical emission,especially for the 18.7-GHz channel.Based on error analyses,a statistical recalibration algorithm was designed and recalibration was performed for the RM level 1B TB.Validation of the recalibrated TB indicated that the quality of the recalibrated RM level 1B TB was improved significantly.The bias of the recalibrated T B at all channels was reduced to<0.4 K,seasonal variation was almost eradicated,and SD was diminished(i.e.,the SD of the 18.7-GHz channel was reduced by more than 0.5K). 展开更多
关键词 HY-2A MICROWAVE RADIOMETER brightness temperature(TB) VERIFICATION calibration
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Plumage brightness and uropygial gland secretions in barn swallows 被引量:2
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作者 Anders PAPE MOLLER Fernando MATEOS-GONZALEZ 《Current Zoology》 SCIE CAS CSCD 2019年第2期177-182,共6页
The uropygial gland has been hypothesized to play a role in sexual signaling through a "make-up" function derived from the effects of secretions from the gland on the appearanee of the plumage and bare parts... The uropygial gland has been hypothesized to play a role in sexual signaling through a "make-up" function derived from the effects of secretions from the gland on the appearanee of the plumage and bare parts of the body. Here we show that plumage brightness of dorsal feathers of individual barn swallows Hirundo rustica was greater in mated than in unmated individuals. In addition, plumage brightness in creased with colony size. Furthermore, plumage bright ness was positively correlated with the amount of wax in the uropygial gland, negatively correlated with time of sampling of uropygial wax (perhaps because more wax is present early in the morning after an entire night of wax production without any preening), and negatively correlated with the number of chewing lice that degrade the plumage. Experimentally preventing barn swallows from access to the uropygial gland reduced plumage brightness, showing a causal link between secretions from the uropygial gland and plumage brightness. These findings provide evidence consistent with a role of uropygial secretions in signaling plumage brightness. 展开更多
关键词 brightness COLORATION preening WAX sexual selection uropygial GLAND
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MODIS BRIGHTNESS TEMPERATURE DATA ASSIMILATION UNDER CLOUDY CONDITIONS Ⅱ: IMPACTS ON RAINSTORM FORECASTING 被引量:4
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作者 丁伟钰 万齐林 +2 位作者 黄燕燕 陈子通 张诚忠 《Journal of Tropical Meteorology》 SCIE 2011年第3期221-230,共10页
Satellite observations provide large amount of information of clouds and precipitation and play an important role in the forecast of heavy rainfall.However,we have not fully taken advantage of satellite observations i... Satellite observations provide large amount of information of clouds and precipitation and play an important role in the forecast of heavy rainfall.However,we have not fully taken advantage of satellite observations in the data assimilation of numerical weather predictions,especially those in infrared channels. It is common to only assimilate radiances under clear-sky conditions since it is extremely difficult to simulate infrared transmittance in cloudy sky.On the basis of the Global and Regional Assimilation and Prediction Enhanced System 3-dimensional variance(GRAPES-3DVar),cloud liquid water content, ice-water content and cloud cover are employed as governing variables in the assimilation system.This scheme can improve the simulation of infrared transmittance by a fast radiative transfer model for TOVS (RTTOV)and adjust the atmospheric and cloud parameters based on infrared radiance observations.In this paper,we investigate a heavy rainfall over Guangdong province on May 26,2007,which is right after the onset of a South China Sea monsoon.In this case,channels of the Moderate Resolution Imaging Spectroradiometer(MODIS)for observing water vapor(Channel 27)and cloud top altitude(Channel 36)are selected for the assimilation.The process of heavy rainfall is simulated by the Weather Research and Forecasting(WRF)model.Our results show that the assimilated MODIS data can improve the distribution of water vapor and temperature in the first guess field and indirectly adjust the upper-level wind field.The tendency of adjustment agrees well with the satellite observations.The assimilation scheme has positive impacts on the short-range forecasting of rainstorm. 展开更多
关键词 MODIS brightness temperature data ASSIMILATION RAINSTORM
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