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多波段红外点目标的夜视成像差异分析 被引量:2
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作者 朱小红 蔺素珍 王栋娟 《红外技术》 CSCD 北大核心 2015年第4期289-295,共7页
通过分析在夜视条件下短波红外、中波红外和长波红外点目标辐射成像机理,明确了多波段红外成像的影响因素,建立了短波红外、中波红外和长波红外图像点目标的形成模型,并对模型进行分析与仿真实验,揭示了多波段红外点目标夜视成像特性差... 通过分析在夜视条件下短波红外、中波红外和长波红外点目标辐射成像机理,明确了多波段红外成像的影响因素,建立了短波红外、中波红外和长波红外图像点目标的形成模型,并对模型进行分析与仿真实验,揭示了多波段红外点目标夜视成像特性差异的形成机理,比较了多波段红外点目标成像的差异,并且通过实验图像的差异特征验证了这些成像特性差异的存在性,最后得出了多波段红外点目标图像的灰度值存在差异,大气传输影响存在差异以及夜光辐射影响存在差异的结论。 展开更多
关键词 短波红外 中波红外 长波红外 红外点目标 夜视成像 成像差异
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MRI与CT成像差异对鼻咽癌临床诊断中价值分析
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作者 王宁 《医学信息(下旬刊)》 2011年第7期333-333,共1页
目的:探讨鼻咽癌临床诊断中MRI与CT的临床诊断价值的差异。方法;选择我院2009年1月至2011年1月收治的鼻咽癌患者90倒,对其分别行MRI扣CT拴查,就其影像学特点进行比较分析。结论:MRI检出咽后淋巴结、颅底骨破坏、椎前肌受累优于CT... 目的:探讨鼻咽癌临床诊断中MRI与CT的临床诊断价值的差异。方法;选择我院2009年1月至2011年1月收治的鼻咽癌患者90倒,对其分别行MRI扣CT拴查,就其影像学特点进行比较分析。结论:MRI检出咽后淋巴结、颅底骨破坏、椎前肌受累优于CT检查结果,有统计学差异(X2≥13.37,P〈0.01)。本组MRI侵度后颅窝对延髓行挤压者4例,侵入颅底硬膜外者2例,在MRI矢状往上,在已呈破坏状态的斜坡后缘紧贴,局部可见有明显增厚的硬脑膜,给予Gd—DTPA注射后可增强,CT检查对以上均不能显示.结论:MRI在优越性上临床实践均证明要好于CT,可作为首选检查鼻咽肿物的影像学方法. 展开更多
关键词 MRI CT 成像差异 鼻咽癌 临床诊断
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Physiological Analysis of Two Arabidopsis thaliana Mutants in Response to CO2 被引量:11
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作者 宋玉伟 陈家宝 刘宗才 《Agricultural Science & Technology》 CAS 2009年第2期12-14,共3页
[Objective] The 15urpose was to seek for the different phenotypes between wild type and Arabidopsis Mutants in response to CO2. [Method] The epidermis bioassays and seed germination test were carried out to analyze th... [Objective] The 15urpose was to seek for the different phenotypes between wild type and Arabidopsis Mutants in response to CO2. [Method] The epidermis bioassays and seed germination test were carried out to analyze the physiological characteristics of two Arabidopsis mu- tants and their wild type. [Result] There existed distinct differences in stomata apertures, water loss and leaf temperature compared with wild type except for stomata density. In addition, seed germination test on the medium indicated that cdfl was insensitive to ABA, mannitol and NaCI, but cdsl performed contrary to cdil. [ Conclusion] There are some different physiological characteristics between wild type and mutants. 展开更多
关键词 Arabidopsis thaliana CO2 MUTANT
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浅谈光电耦合器CCD和CMOS的区别 被引量:1
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作者 王树刚 余新 《科技信息》 2009年第14期311-311,共1页
文章概述了光电耦合器件的发展历程,并详细的介绍了光电耦合器、什么是CCD器件、什么是CMOS器件。并说明了CCD器件和CMOS器件的区别与联系。
关键词 光电耦合器 CCD CMOS 信息读取方式 噪点差异 耗电量差异成像质量
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MR-arterioportography: A new technical approach for detection of liver lesions 被引量:2
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作者 Janine Rennert Ernst-Michael Jung +4 位作者 Andreas G Schreyer Patrick Hoffstetter Peter Heiss Stefan Feuerbach Niels Zorger 《World Journal of Gastroenterology》 SCIE CAS CSCD 2011年第13期1739-1745,共7页
AIM: To evaluate the benefit and effectiveness of MRarterioportography (MR-AP) to achieve the highest sensitivity for detection and evaluation of hepatocellular carcinoma (HCC). METHODS: Twenty liver cirrhosis patient... AIM: To evaluate the benefit and effectiveness of MRarterioportography (MR-AP) to achieve the highest sensitivity for detection and evaluation of hepatocellular carcinoma (HCC). METHODS: Twenty liver cirrhosis patients with suspected HCC were included before transarterial chemoembolization. In all patients double-enhanced Magnetic resonance imaging (MRI) was performed. A bolus of 10 mL Magnevist was injected through a selectively placed catheter in the superior mesenteric artery and MRI of the liver was performed in arterioportographic phase. Two independent readers evaluated number, size and localization of detected lesions. Diagnostic quality was determined using a 4-point scale. Differences were analyzed for significance using a t -test. Interobserver variability was calculated. RESULTS: In all 20 patients (100%), MR-AP was feasible. Diagnostic quality was, in all cases, between 1 and2 for both modalities and readers. MR-AP detected significantly more lesions than double-enhanced MRI (102.5 vs 61, respectively, P < 0.0024). The inter-observer variability was 0.881 for MRI and 0.903 for MR-AP. CONCLUSION: Our study confirmed that the MR-AP as an additional modality for detection of HCC is beneficial, as significantly more lesions were detected compared to MRI with liver-specific contrast. 展开更多
关键词 MR-arterioportography Magnetic resonance imaging Hepatocellular carcinoma Liver lesions
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基于Shearlet变换的SAR与多光谱遥感影像融合 被引量:14
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作者 邰建豪 潘斌 +1 位作者 赵珊珊 赵园 《武汉大学学报(信息科学版)》 EI CSCD 北大核心 2017年第4期468-474,共7页
针对合成孔径雷达(SAR)影像和多光谱遥感影像在融合时空间特征和光谱特征方面不能同时得到较大改善的问题,提出了一种基于成像特性的Shearlet变换域下的多源遥感影像融合方法。利用Shearlet变换的多方向和多尺度分解特性,将多光谱影像和... 针对合成孔径雷达(SAR)影像和多光谱遥感影像在融合时空间特征和光谱特征方面不能同时得到较大改善的问题,提出了一种基于成像特性的Shearlet变换域下的多源遥感影像融合方法。利用Shearlet变换的多方向和多尺度分解特性,将多光谱影像和SAR影像分别分解为高频和低频系数,从影像区域能量特征和区域相关性入手,设计了基于区域能量的低频系数融合规则和改进型的脉冲耦合神经网络的高频系数融合规则,使融合结果能够包含更多空间细节信息和光谱信息。利用TerraSAR-X、Landsat5-TM影像进行实验,结果表明该方法在提高影像空间细节表达能力的同时能够较好地融合更多的光谱信息。与小波变换、非下采样轮廓波变换(Nonsubsampled contourlet Transform,NSCT)等方法相比,该方法在空间信息保有量和光谱信息保有量方面都有明显的提升,其中交叉熵有接近100%的提升幅度,互相关系数有高于25%的提升幅度,光谱扭曲度有优于40%的提升幅度。 展开更多
关键词 多源影像融合 SHEARLET变换 成像机理差异 SAR 多光谱影像 脉冲耦合神经网络
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Insights into photoluminescence mechanisms of carbon dots:advances and perspectives 被引量:40
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作者 Lin Ai Yisen Yang +4 位作者 Boyang Wang Junbiao Chang Zhiyong Tang Bai Yang Siyu Lu 《Science Bulletin》 SCIE EI CSCD 2021年第8期839-856,M0004,共19页
Carbon dots(CDs) are potentially useful in many areas such as bioimaging, light-emitting diodes, and sensing because of their excellent optical properties, high biocompatibility, and low toxicity.Knowledge of their ph... Carbon dots(CDs) are potentially useful in many areas such as bioimaging, light-emitting diodes, and sensing because of their excellent optical properties, high biocompatibility, and low toxicity.Knowledge of their photoluminescence(PL) mechanisms, which have been widely studied, is of significance in guiding the synthesis and promoting applications of CDs with tunable PL emissions. However,the intrinsic mechanism of PL emission remains unclear, and a unified mechanism has not been found because of differences in particle structures. This review generalizes the categories of CDs, noting their structural diversity. Three types of PL mechanism pertaining to structural differences are outlined: internal factors dominated emission(including the conjugation effect, the surface state, and the synergistic effect), external factors dominated emission(including the molecular state and the environment effect),and crosslink-enhanced emission. Optical applications of CDs are also briefly mentioned. Finally, the prospects for research into PL mechanisms are discussed, noting the remaining challenges and directions for future work. 展开更多
关键词 Carbon dots Photoluminescence mechanisms Surface state Molecular state Crosslink-enhanced emission
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