期刊文献+
共找到2,840篇文章
< 1 2 142 >
每页显示 20 50 100
基于Hessian 矩阵范数正则化方法的共聚焦图像复原 预览
1
作者 陈集懿 何涛 胡洁 《计算机系统应用》 2020年第2期228-232,共5页
对于泊松噪声污染下的模糊共聚焦图像复原问题,为解决传统方法中存在的阶梯效应,提出了一种基于Hessian矩阵范数的正则化方法.在泊松概率模型的基础上,该方法引入Hessian矩阵范数作为正则条件,并应用交替方向乘子法和梯度投影方法求解... 对于泊松噪声污染下的模糊共聚焦图像复原问题,为解决传统方法中存在的阶梯效应,提出了一种基于Hessian矩阵范数的正则化方法.在泊松概率模型的基础上,该方法引入Hessian矩阵范数作为正则条件,并应用交替方向乘子法和梯度投影方法求解最优化模型.在激光扫描共聚焦显微镜实验中,所获得的复原图像质量优于传统方法,此结果证明了该方法可以有效地复原泊松噪声污染下的模糊共聚焦图像. 展开更多
关键词 共聚焦 图像复原 正则化
在线阅读 下载PDF
二维光子晶体双重亚波长成像 预览
2
作者 牛金科 梁斌明 +1 位作者 庄松林 陈家璧 《光电工程》 CAS CSCD 北大核心 2019年第8期66-72,共7页
本文基于硅基底空气孔型二维光子晶体(photonic crystals),提出了一种可以实现等效负折射和亚波长成像的结构。点光源通过三角形光子晶体出射后在两侧形成两个像点。通过在光子晶体两侧添加光栅,增加了光源的透过率,消除了旁斑对双重像... 本文基于硅基底空气孔型二维光子晶体(photonic crystals),提出了一种可以实现等效负折射和亚波长成像的结构。点光源通过三角形光子晶体出射后在两侧形成两个像点。通过在光子晶体两侧添加光栅,增加了光源的透过率,消除了旁斑对双重像点的影响。当光栅的空气带隙宽度w=0.76a和到光子晶体的距离dg=0.1a时,左侧像点image1的最小半宽度达到0.433λ,此时右侧像点image2达到0.842λ,均小于入射波长。另外,当光源波长在3.19a到3.26a范围内时,光子晶体可以实现宽光谱的双重亚波长成像。最后,根据点光源和双重像点的位置变化,求出了关于其坐标x, z的相对关系。 展开更多
关键词 光子晶体 负折射 双重成像 亚波长成像 共聚焦
在线阅读 下载PDF
Morphological and cytological changes of meibomian glands in patients with type 2 diabetes mellitus
3
作者 Tao Yu Xu-Guang Han +2 位作者 Yang Gao Ai-Ping Song Guang-Fu Dang 《国际眼科杂志:英文版》 SCIE CAS 2019年第9期1415-1419,共5页
AIM: To observe the changes of microcellular structure of meibomian glands(MGs) in type 2 diabetes mellitus(DM), and to explore its correlation with the duration of diabetes.METHODS: The study assessed 132 eyes of 132... AIM: To observe the changes of microcellular structure of meibomian glands(MGs) in type 2 diabetes mellitus(DM), and to explore its correlation with the duration of diabetes.METHODS: The study assessed 132 eyes of 132 patients with type 2 diabetes mellitus(DM group) and 100 eyes of 100 non-diabetic participants(NDM group). All patients underwent the examination of the Keratograph 5 M system to obtain the meibography which were used to evaluate the structure dropout of the MGs. And then laser scanning confocal microscopy(LSCM) was performed for observing the acinar cells and ducts of the MGs to obtain the following parameters: the MG acinar unit density(MGAUD), MG acinar longest diameter(MGALD) and MG acinar shortest diameter(MGASD). The examination results of the right eye were selected for analysis.RESULTS: Compared with that in NDM group, the meiboscore was significantly higher(Z=-4.057, P<0.001), and there were more MGs dropout in DM group. With the prolongation of the course of diabetes, the absence of MGs aggravated and the MGs dropout score increased(r=0.596;P<0.001). LSCM showed that there were various cytological alterations in acinar cells of MGs with the progress of diabetes duration, such as expansion, atrophy or fibrosis of MG acinar units, decreased density of MG acinar units, deposition of lipid substances, infiltration of inflammatory cells, proliferation of fibrous tissues, etc. And the opening of the glandular duct changed from smooth at the beginning to narrow, blocked, fibrotic and so on. Compared with that in NDM group, the MGAUD in DM group was significantly lower(Z=-9.713;P<0.001), the MGALD and MGASD were significantly larger(Z=-9.751,-6.416;P<0.001). With the duration of diabetes, the MGAUD reduced, the MGASD increased(r=0.860, 0.364, P<0.001);but the MGALD had no correlation with diabetic duration(r=0.133, P=0.151).CONCLUSION: With the progress of diabetes, the meibomian glandular acinar cells of diabetic patients show various manifestations. Those changes may result in the dysfuction of 展开更多
关键词 diabetes meibomian GLANDS TEAR films keratograph laser scanning CONFOCAL MICROSCOPY
不同时期黄褐斑皮损三种皮肤影像的形态学分析
4
作者 陈荣 许爱娥 《中华皮肤科杂志》 CAS CSCD 北大核心 2019年第2期103-106,共4页
目的运用三种皮肤影像技术探究女性黄褐斑不同时期皮损的形态。方法2017年6月至2018年1月,在杭州市第三人民医院门诊收集女性黄褐斑患者253例。结合临床分期标准,应用反射式共聚焦显微镜(RCM)、VISIA皮肤图像检测仪、皮肤镜观察不同时... 目的运用三种皮肤影像技术探究女性黄褐斑不同时期皮损的形态。方法2017年6月至2018年1月,在杭州市第三人民医院门诊收集女性黄褐斑患者253例。结合临床分期标准,应用反射式共聚焦显微镜(RCM)、VISIA皮肤图像检测仪、皮肤镜观察不同时期黄褐斑皮损,分析临床分期与树突状黑素细胞、亚临床黄褐斑、血管形态改变的相关性。采用SPSS19.0统计学软件,计数资料比较采用卡方检验及独立样本Mann-WhitneyU检验。结果253例患者中,进展期100例,稳定期153例。进展期患者中78例(78%)RCM下有树突状黑素细胞,稳定期中22例(14.4%)可见树突状黑素细胞,两组间差异有统计学意义(χ^2=102.40,P<0.01)。VISIA皮肤图像检测仪观察显示,进展期患者中78例(78%)有亚临床黄褐斑,稳定期患者25例有亚临床黄褐斑(16.3%),进展期亚临床黄褐斑出现率高于稳定期(χ^2=95.26,P<0.01)。皮肤镜显示,进展期患者血管改变发生率为74%(74/100),稳定期为68.6%(105/153),两组差异无统计学意义(χ^2=0.84,P=0.39)。结论RCM、VISIA皮肤图像检测仪下分别观察的树突状黑素细胞及亚临床表现可作为黄褐斑临床分期的参考指标。 展开更多
关键词 黄褐斑 黑素细胞 显微镜检查 共焦 皮肤镜 临床分期 皮肤图像检测仪
炫彩多色共焦眼底层析激光成像联合扫频光相干断层扫描成像对病理性近视漆裂纹及牵拉条纹的诊断价值
5
作者 华怡红 陈秋莹 +4 位作者 周皓 王凯 孙豪龙 王卫峻 樊莹 《中华眼底病杂志》 CAS CSCD 北大核心 2019年第5期435-440,共6页
目的观察分析炫彩多色共焦眼底层析激光成像联合扫频OCT(SS-OCT)成像对病理性近视漆裂纹及牵拉条纹(MSL)的诊断价值。方法观察性研究。2017年5月至2018年1月在上海交通大学附属上海市第一人民医院高度近视专科门诊就诊的病理性近视患者5... 目的观察分析炫彩多色共焦眼底层析激光成像联合扫频OCT(SS-OCT)成像对病理性近视漆裂纹及牵拉条纹(MSL)的诊断价值。方法观察性研究。2017年5月至2018年1月在上海交通大学附属上海市第一人民医院高度近视专科门诊就诊的病理性近视患者58例83只眼纳入研究。其中,男性20例30只眼,女性38例53只眼。年龄24~70岁,平均年龄(50.65±12.02)岁。患眼平均BCVA0.37±0.32,平均等效球镜度数(?11.38±4.96)D,平均眼轴长度(28.91±2.15)mm。所有患者采用海德堡眼底血管造影仪行FFA和ICGA检查,采集FFA、ICGA、红外线(IR)、自身荧光(AF)像。采用SS-OCT进行双眼黄斑中心凹及视盘扫描,范围9 mm×9 mm,采集B-scan像、无赤光像、彩色眼底像;采用炫彩多色共焦眼底层析激光成像技术,以黄斑为中心拍摄30°×30°大小的炫彩标准图像和红外反射像。所有影像资料由三位眼底病医生分别进行独立阅片,并行一致性检验。漆裂纹的明确诊断以FFA线性强荧光影和ICGA晚期线性弱荧光影为标准,MSL则以FFA和ICGA同时表现为弱荧光线状影为诊断标准。计算不同影像模式对病理性近视漆裂纹及MSL的检出率,并行准确性检验。筛选检出率最高的影像模式联合SS-OCT进一步检验检出率。结果三位眼底病医师阅片结果经一致性检验,其阅片诊断结果一致性较好(Kappa=0.938,P<0.01)。炫彩标准图像、SS-OCT无赤光像、SS-OCT彩色眼底像、IR像、AF像对眼底漆裂纹及MSL病灶的检出率依次递减;其检出阳性率分别为77.1%、73.1%、72.3%、72.3%、49.4%。炫彩标准图像检验一致性(Kappa=0.520,P<0.01)和检验准确性(受试者工作特征曲线下面积为0.750)最佳。采用炫彩标准图像联合SS-OCT鉴别诊断漆裂纹和MSL,漆裂纹的检出阳性率为91.7%,漆裂纹+MSL的检出阳性率为93.3%,MSL的检出阳性率为91.2%。在SS-OCT B-scan像中,漆裂纹主要表现为RPE条带模糊不均,局部变薄透见,椭� 展开更多
关键词 近视 退行性/诊断 显微镜检查 共焦 体层摄影术 光学相干
Advanced diagnostics for pancreatic cysts: Confocal endomicroscopy and molecular analysis 预览
6
作者 Claire Durkin Somashekar G Krishna 《世界胃肠病学杂志:英文版》 SCIE CAS 2019年第22期2734-2742,共9页
Technological advances and the widespread use of medical imaging have led to an increase in the identification of pancreatic cysts in patients who undergo crosssectional imaging. Current methods for the diagnosis and ... Technological advances and the widespread use of medical imaging have led to an increase in the identification of pancreatic cysts in patients who undergo crosssectional imaging. Current methods for the diagnosis and risk-stratification of pancreatic cysts are suboptimal, resulting in both unnecessary surgical resection and overlooked cases of neoplasia. Accurate diagnosis is crucial for guiding how a pancreatic cyst is managed, whether with surveillance for low-risk lesions or surgical resection for high-risk lesions. This review aims to summarize the current literature on confocal endomicroscopy and cyst fluid molecular analysis for the evaluation of pancreatic cysts. These recent technologies are promising adjuncts to existing approaches with the potential to improve diagnostic accuracy and ultimately patient outcomes. 展开更多
关键词 PANCREATIC CYSTS CONFOCAL ENDOMICROSCOPY MOLECULAR analysis MOLECULAR biomarkers PANCREATIC cancer
在线阅读 免费下载
Simultaneous,hybrid single-molecule method by optical tweezers and fluorescence 预览
7
作者 Guoteng Ma Chunguang Hu +3 位作者 Shuai Li Xiaoqin Gao Hongbin Li Xiaotang Hu 《纳米技术与精密工程(英文)》 CAS CSCD 2019年第4期145-156,共12页
As studies on life sciences progress toward the single-molecule level,new experiments have put forward more requirements for simultaneously displaying the mechanical properties and conformational changes of biomolecul... As studies on life sciences progress toward the single-molecule level,new experiments have put forward more requirements for simultaneously displaying the mechanical properties and conformational changes of biomolecules.Optical tweezers and fluorescence microscopy have been combined to solve this problem.The combination of instruments forms a new generation of hybrid single-molecule technology that breaks through the limitations of traditional biochemical analysis.Powerfulmanipulation and fluorescence visualization have beenwidely used,and these techniques provide new possibilities for studying complex biochemical reactions at the singlemolecule level.This paper explains the features of this combined technique,including the application characteristics of single-trap and dual-traps,the anti-bleaching method,and optical tweezers combined with epifluorescence,confocal fluorescence,total internal reflection fluorescence,and other fluorescence methods.Using typical experiments,we analyze technical solutions and explain the factors and principles that instrument designers should consider.This review aims to give an introduction to this novel fusion technology process and describe important biological results. 展开更多
关键词 SINGLE-MOLECULE Optical tweezers Confocal fluorescence FRET TIRF
在线阅读 下载PDF
唐代彩绘镇墓兽的激光显微共焦拉曼光谱分析 预览
8
作者 侯鲜婷 《自然与文化遗产研究》 2019年第7期96-99,共4页
激光显微共焦拉曼光谱分析技术具有灵敏度高、微区及无损等优点,可对微米级的样品进行精准分析。在样品量极为有限且难以在珍贵的文物上采集的情况下,文章采用激光显微共焦拉曼光谱仪对该唐代彩绘镇墓兽上的彩绘样品及金属锈蚀物进行分... 激光显微共焦拉曼光谱分析技术具有灵敏度高、微区及无损等优点,可对微米级的样品进行精准分析。在样品量极为有限且难以在珍贵的文物上采集的情况下,文章采用激光显微共焦拉曼光谱仪对该唐代彩绘镇墓兽上的彩绘样品及金属锈蚀物进行分析,判定其物质组成,从而为后续该文物的保护修复方法和材料的选择提供科学依据。 展开更多
关键词 镇墓兽 彩绘 锈蚀物 共焦 拉曼光谱
在线阅读 下载PDF
NIR-II fluorescence in vivo confocal microscopy with aggregation-induced emission dots
9
作者 Wenbin Yu Bing Guo +7 位作者 Hequn Zhang Jing Zhou Xiaoming Yu Liang Zhu Dingwei Xue Wen Liu Xianhe Sun Jun Qian 《科学通报:英文版》 SCIE EI CSCD 2019年第6期410-416,共7页
Significantly reduced tissue scattering of fluorescence signals in the second near-infrared(NIR-Ⅱ,1,000–1,700 nm)spectral region offers opportunities for large-depth in vivo bioimaging.Nowadays,most reported works c... Significantly reduced tissue scattering of fluorescence signals in the second near-infrared(NIR-Ⅱ,1,000–1,700 nm)spectral region offers opportunities for large-depth in vivo bioimaging.Nowadays,most reported works concerning NIR-II fluorescence in vivo bioimaging are realized by wide-field illumination and 2D-arrayed detection(e.g.,via InGaAs camera),which has high temporal resolution but limited spatial resolution due to out-of-focus signals.Combining NIR-II fluorescence imaging with confocal microscopy is a good approach to achieve high-spatial resolution visualization of biosamples even at deep tissues.In this presented work,a NIR-II fluorescence confocal microscopic system was setup.By using a kind of aggregation-induced emission(AIE)dots as NIR-II fluorescent probes,800 lm-deep 3D in vivo cerebrovascular imaging of a mouse was obtained,and the spatial resolution at 700 lm depth could reach 8.78 lm.Moreover,the time-correlated single photon counting(TCSPC)technique and femtosecond laser excitation were introduced into NIR-II fluorescence confocal microscopy,and in vivo confocal NIR-II fluorescence lifetime microscopic imaging(FLIM)of mouse cerebral vasculature was successfully realized. 展开更多
关键词 Confocal microscopy NIR-II FLUORESCENCE AIE DOTS In vivo cerebrovascular IMAGING TCSPC FLIM IMAGING
Corneal re-innervation following refractive surgery treatments 预览
10
作者 Francisco Bandeira Nur Zahira Yusoff +1 位作者 Gary Hin-Fai Yam Jodhbir Singh Mehta 《中国神经再生研究:英文版》 SCIE CAS CSCD 2019年第4期557-565,共9页
Laser refractive surgery is one of the most performed surgical procedures in the world.Although regarded safe and efficient,it has side effects.All of the laser based refractive surgical procedures invoke corneal nerv... Laser refractive surgery is one of the most performed surgical procedures in the world.Although regarded safe and efficient,it has side effects.All of the laser based refractive surgical procedures invoke corneal nerve injury to some degree.The impact of this denervation can range from mild discomfort to neurotrophic corneas.Currently,three techniques are widely used for laser vision correction:small incision lenticule extraction,laser-assisted keratomileusis in situ and photorefractive keratotomy.Each of these techniques affects corneal innervation differently and has a different pattern of nerve regeneration.The purpose of this review is to summarize the different underlying mechanisms for corneal nerve injury and compare the different patterns of corneal reinnervation. 展开更多
关键词 PHOTOREFRACTIVE KERATOTOMY small INCISION manual lenticule extraction laser-assisted KERATOMILEUSIS in situ refractive surgery in vivo confocal microscopy CORNEAL sensation CORNEAL nerve
在线阅读 下载PDF
Corneal esthesiometry and sub-basal nerves morphological changes in herpes simplex virus keratitis/uveitis patients
11
作者 Reda Zemaitiene Modesta Rakauskiene +3 位作者 Viliija Danileviciene Violeta Use Loresa Kriauciuniene Dalia Zaliuniene 《国际眼科杂志:英文版》 SCIE CAS 2019年第3期407-411,共5页
AIM: To describe and compare corneal sensation and morphological changes of sub-basal corneal nerves by in vivo laser scanning confocal microscopy(LSCM) in herpes simplex virus(HSV) keratitis/uveitis and contralateral... AIM: To describe and compare corneal sensation and morphological changes of sub-basal corneal nerves by in vivo laser scanning confocal microscopy(LSCM) in herpes simplex virus(HSV) keratitis/uveitis and contralateral, clinically unaffected eyes. METHODS: A prospective clinical study included 30 HSV eyes and 30 contralateral eyes of 30 patients, diagnosed with unilateral HSV keratitis/uveitis. Both eyes underwent a complete ophthalmological examination, Cochet-Bonnet aesthesiometry and LSCM of the central cornea, using the Heidelberg Retina Tomograph III Rostock Cornea Module. After 6 mo, the same examination of the HSV affected and contralateral, clinically unaffected eyes was performed.RESULTS: HSV eyes, as compared to contralateral eyes, demonstrated a significant decrease in mean corneal sensation(3.1±1.6 vs 5.3±0.8 cm), total nerve fibres number(5.7±4.4 vs 15.1±5.4), nerve branches(3.4±3.0 vs 8.4±4.7), main nerve trunks(2.3±1.6 vs 5.8±2.2), and nerve fibres density(7.5±5.6 vs 18.1±5.3 mm/mm2, P<0.05). There was no significant difference between keratitis and uveitis eyes in mean corneal sensation and nerve fibres parameters. After 6 mo, corneal sensation and sub-basal nerve fibres parameters were increased significantly, but did not reach the parameters of contralateral, clinically unaffected eyes.CONCLUSION: Corneal aesthesiometry and LSCM in HSV affected eyes reveals a significant decrease of corneal sensation and sub-basal nerve fibres which recovers at6 mo but does not reach the normal level. 展开更多
关键词 aesthesiometry CONFOCAL microscopy HERPES simplex virus KERATITIS UVEITIS
基于单步驱动的激光共焦显微镜快速定焦方法
12
作者 於维华 王允 +2 位作者 邱丽荣 吴寒旭 赵维谦 《光学技术》 CAS CSCD 北大核心 2019年第5期535-540,共6页
针对现有共焦显微镜中定焦速度慢和定焦精度差的问题,提出了基于单步驱动的激光共焦显微镜快速定焦方法。充分利用轴向扫描器件的响应时间通过单步驱动获取数据,大幅提高采集速度,提高系统信噪比;通过拟合区间优化和分开拟合的数据处理... 针对现有共焦显微镜中定焦速度慢和定焦精度差的问题,提出了基于单步驱动的激光共焦显微镜快速定焦方法。充分利用轴向扫描器件的响应时间通过单步驱动获取数据,大幅提高采集速度,提高系统信噪比;通过拟合区间优化和分开拟合的数据处理方法来快速、准确获取定焦目标位置,进而实现激光共焦显微镜轴向定焦效率的提升。理论分析与实验结果表明:与现有定焦方法相比,方法在粗定焦阶段使定焦速度提升5.64倍,在准确定焦阶段使定焦速度提升3.08倍,其有效提升了现有共焦显微镜的轴向定焦速度和精度。 展开更多
关键词 光学测量 共焦 快速定焦 单步驱动
新型眼底影像检查技术在糖尿病视网膜病变诊断中的应用 被引量:1
13
作者 李晓莉 孟倩丽 +2 位作者 谢洁 陈湘婷 黄天 《中华眼底病杂志》 CAS CSCD 北大核心 2019年第1期90-94,共5页
糖尿病视网膜病变(DR)是导致糖尿病患者视力损伤和失明的主要原因,寻求更简便、安全、无创、高效的诊查及监控方法尤为重要。近年推出的多种新型眼底影像检查技术在DR的早期诊断、指导治疗和随访监测中显示出了独特的优势。广角激光扫... 糖尿病视网膜病变(DR)是导致糖尿病患者视力损伤和失明的主要原因,寻求更简便、安全、无创、高效的诊查及监控方法尤为重要。近年推出的多种新型眼底影像检查技术在DR的早期诊断、指导治疗和随访监测中显示出了独特的优势。广角激光扫描眼底成像系统具有免散瞳、快速、无创、成像范围广等特点,包括广角眼底照相、超广角FFA、广角FAF等多种激光扫描模式,可通过不同波长成像定位病变位置。多光谱眼底分层成像系统可识别DR的微动脉瘤、视网膜出血、渗出等,因其无创、方便、快捷,已逐渐用于DR的筛查、诊断和随访。OCT血管成像技术可对黄斑中心凹无血管区面积、黄斑血流密度等进行定量检测,为临床提供多元化的DR诊断依据和评估手段。这些新型眼底影像检查技术的不断完善将对建立个性化的DR评估体系提供重要的技术支持。 展开更多
关键词 糖尿病视网膜病变/诊断 检眼镜检查 显微镜检查 共焦 体层摄影术 光学相干 彩色眼底照相
Corneal alteration and pathogenesis in diabetes mellitus
14
作者 Han Zhao Yan He +1 位作者 Yue-Rong Ren Bai-Hua Chen 《国际眼科杂志:英文版》 SCIE CAS 2019年第12期1939-1950,共12页
The incidence of diabetes mellitus(DM) and its complications have increased considerably worldwide. Diabetic keratopathy is the major complication of the cornea characterized by delayed corneal wound healing, decreasi... The incidence of diabetes mellitus(DM) and its complications have increased considerably worldwide. Diabetic keratopathy is the major complication of the cornea characterized by delayed corneal wound healing, decreasing corneal epithelial sensitivity, and recurrent corneal ulcers. There is accumulating evidence that diabetic keratopathy is correlated with the hyperglycemic state. Different corneal components may produce different alterations under hyperglycemia. In addition, diabetic nerve alteration may become a novel biomarker of earlystage DM. Abnormalities of the corneal nerve plexus have been associated with diabetic inflammatory states. There is rapidly growing evidence based on investigations of diabetic corneal nerves through in vivo confocal microscopy. Understanding the molecular pathogenesis caused by hyperglycemia may assist in the identification of novel biomarkers, as well as therapeutic targets for early treatment. This review mainly summarizes recent findings on corneal alteration and pathogenesis in DM. 展开更多
关键词 diabetes mellitus diabetic keratopathy diabetic neuropathy in vivo confocal microscopy advanced glycation end products
Effect of titanium content on the precipitation behavior of carbon-saturated molten pig iron 预览
15
作者 Lei-zhang Gao Tong-xiang Ma +3 位作者 Meng-jun Hu Zhi-ming Yan Xue-wei Lü Mei-long Hu 《矿物冶金与材料学报:英文版》 SCIE EI CAS CSCD 2019年第4期483-492,共10页
The use of iron ores bearing titanium as a raw material is an effective measure to prevent hearth erosion and prolong the life of a blast furnace.In this research,the effect of titanium content on the precipitation be... The use of iron ores bearing titanium as a raw material is an effective measure to prevent hearth erosion and prolong the life of a blast furnace.In this research,the effect of titanium content on the precipitation behaviors of high-melting phases of carbon-saturated molten pig iron were studied by confocal scanning laser microscopy.The results showed that,when the titanium content was less than 0.25wt%,Fe3C was precipitated as a single phase from the molten carbon-saturated iron.The growth rate of the precipitated Fe3C crystals was very high,reaching 7387μm2/s.When the titanium content in the molten pig iron was greater than 0.47wt%,TiC crystals precipitated first.The shape and size of the precipitated TiC crystals did not obviously change.After TiC was precipitated,the fluidity of the molten pig iron worsened.With a decrease in temperature,Fe3C was also precipitated but the growth rate of Fe3C was limited by the presence of the first precipitated TiC phase.The crystal size of the precipitated Fe3C was much smaller than that of pure Fe3C. 展开更多
关键词 carbon-saturated MOLTEN pig iron precipitation behavior TITANIUM TITANIUM CARBIDE CONFOCAL scanning laser microscopy
在线阅读 下载PDF
原发性皮肤淀粉样变反射式共聚焦显微镜成像特征分析
16
作者 王蕾 黄骏 +1 位作者 单筠筠 许爱娥 《中华皮肤科杂志》 CAS CSCD 北大核心 2019年第4期265-267,共3页
目的利用反射式共聚焦显微镜(RCM)观察原发性皮肤淀粉样变的成像特征。方法对2015年6月至2016年10月杭州市第三人民医院皮肤科门诊收集的30例临床确诊为原发性皮肤淀粉变患者的皮损进行RCM观察和组织病理检查,分析RCM特征。结果原发性... 目的利用反射式共聚焦显微镜(RCM)观察原发性皮肤淀粉样变的成像特征。方法对2015年6月至2016年10月杭州市第三人民医院皮肤科门诊收集的30例临床确诊为原发性皮肤淀粉变患者的皮损进行RCM观察和组织病理检查,分析RCM特征。结果原发性皮肤淀粉变皮损RCM检查显示,角化过度22例,棘层肥厚15例,基底层色素增加20例,真皮乳头及浅层色素失禁20例,30例真皮乳头增大出现多形性,且可见高折光的团块状物质。这些RCM主要特征与组织病理有较高的一致性。结论原发性皮肤淀粉样变在RCM下的典型特征为真皮乳头内呈现折光度较高的团块状物质,RCM可作为原发性皮肤淀粉样变的无创性辅助诊断技术。 展开更多
关键词 淀粉样变性 显微镜检查 共焦
宽光谱共焦复消色差物镜光学系统设计
17
作者 葛琳琳 王世先 +2 位作者 张瑞 闫学纯 杨亚林 《光学与光电技术》 2019年第6期107-112,共6页
为满足昼夜观察的需求,设计了一款大相对孔径的可见光/近红外波段的复消色差物镜。在可见/近红外波段,分析了光学玻璃材料的色散特性,为复消色差物镜的光学设计工作提供了理论支撑。设计结果显示:选择合适的光学玻璃材料,二级光谱得到... 为满足昼夜观察的需求,设计了一款大相对孔径的可见光/近红外波段的复消色差物镜。在可见/近红外波段,分析了光学玻璃材料的色散特性,为复消色差物镜的光学设计工作提供了理论支撑。设计结果显示:选择合适的光学玻璃材料,二级光谱得到了很好的校正。物镜焦距7.4 mm,相对孔径1∶1.2,视场为44°,畸变为-0.7%,系统总长为15.5 mm。此共焦型物镜在光谱范围486~950 nm条件下,实现了无需调焦满足昼夜观察的使用需求,可广泛应用于安防监控、车载镜头等领域。 展开更多
关键词 光学系统设计 二级光谱 大相对孔径 宽光谱 共焦
基于二维光子晶体负折射的共聚焦系统
18
作者 牛金科 梁斌明 +2 位作者 庄松林 王国旭 雷雨 《激光与光电子学进展》 CSCD 北大核心 2019年第2期27-31,共5页
基于二维光子晶体的负折射和亚波长成像特性,提出了一种可以实现超分辨成像的共聚焦系统,使用时域有限差分法(FDTD)仿真了共聚焦系统的聚焦和成像的过程。在焦点离光子晶体透镜下表面1.55μm处,横坐标X=4μm时,焦点半峰全宽(FWHM)为0.59... 基于二维光子晶体的负折射和亚波长成像特性,提出了一种可以实现超分辨成像的共聚焦系统,使用时域有限差分法(FDTD)仿真了共聚焦系统的聚焦和成像的过程。在焦点离光子晶体透镜下表面1.55μm处,横坐标X=4μm时,焦点半峰全宽(FWHM)为0.593λ,小于入射波长,此时反射光在右侧像点的FWHM达到0.496λ,实现了超分辨成像,并且随着焦点的右移,像点FWHM不断减小。同时,在针孔和焦点位置不变时共聚焦系统的轴向分辨率达到2.2λ。 展开更多
关键词 衍射 光子晶体 负折射 共聚焦 亚波长成像 超分辨成像
自适应光学扫描技术在眼底检查中的应用进展
19
作者 张剑平 张美霞 《中华眼底病杂志》 CAS CSCD 北大核心 2019年第6期621-623,共3页
自适应光学(AO)是一种通过降低光学像差的影响以提高光学系统性能的技术,与扫描激光检眼镜结合(AOSLO)应用于眼科可以矫正人眼屈光系统的像差,从而极大地提高成像的分辨率和成像质量。AOSLO能够在活体视网膜上观察到细胞水平的微观结构... 自适应光学(AO)是一种通过降低光学像差的影响以提高光学系统性能的技术,与扫描激光检眼镜结合(AOSLO)应用于眼科可以矫正人眼屈光系统的像差,从而极大地提高成像的分辨率和成像质量。AOSLO能够在活体视网膜上观察到细胞水平的微观结构如光感受器、神经纤维、血管壁细胞等,从而可以发现疾病的早期改变,同时在疾病的随访中亦可观察视网膜微观结构的改变。目前,由于AOSLO内部固有的技术缺陷,限制了其在临床的广泛应用。随着AO技术的不断进步,相关软件功能的进一步完善,系统将变得更加成熟,必将在科研和临床中发挥越来越重要的作用。 展开更多
关键词 显微镜检查 共焦 综述 自适应光学
飞秒激光辅助与微切口超声乳化白内障摘出术对眼表功能影响的比较 预览
20
作者 许荣 赵少贞 《中华实验眼科杂志》 CAS CSCD 北大核心 2019年第11期907-913,共7页
目的比较飞秒激光辅助与微切口超声乳化白内障摘出术对眼表功能的影响。方法采用非随机对照研究设计。连续收集2018年1—3月在武汉爱尔眼科汉口医院就诊的年龄相关性白内障患者116例116眼,根据患者自愿选择的白内障手术方式分为飞秒激... 目的比较飞秒激光辅助与微切口超声乳化白内障摘出术对眼表功能的影响。方法采用非随机对照研究设计。连续收集2018年1—3月在武汉爱尔眼科汉口医院就诊的年龄相关性白内障患者116例116眼,根据患者自愿选择的白内障手术方式分为飞秒激光辅助的超声乳化白内障摘出术组(简称飞秒组)55眼和微切口超声乳化白内障摘出术(简称微切口组)61眼。观察2个组术前,术后7 d、30 d眼表疾病指数(OSDI)、泪膜破裂时间(BUT)、角膜荧光素染色评分、基础泪液分泌试验(SⅠt)、结膜杯状细胞密度的变化。结果术后1 d,飞秒组和微切口组最佳矫正远视力(BCDVA)(LogMAR视力)分别为0.14(0.10,0.24)和0.20(0.17,0.27),飞秒组视力较微切口组好,差异有统计学意义(U=-3.140,P=0.002)。与微切口组比较,飞秒组手术时间略长,但超声时间更短,累计能量复合参数(CDE)值更低,平衡盐溶液(BSS)灌注量更少,2个组比较差异均有统计学意义(均P<0.001)。2个组术后7 d、30 d OSDI评分、BUT值、结膜杯状细胞密度均较术前降低,角膜荧光素染色评分均较术前明显升高,差异均有统计学意义(均P<0.05)。2个组手术前后不同时间点SⅠt值波动均较小,组间和不同时间点间总体比较差异均无统计学意义(F分组=0.510,P=0.477;F时间=0.741,P=0.479)。结论与微切口超声乳化白内障摘出术相比,飞秒激光辅助的超声乳化白内障摘出术后早期角膜荧光素染色评分升高、泪膜稳定性下降、结膜杯状细胞密度下降更明显。 展开更多
关键词 白内障/手术 飞秒激光/治疗应用 干眼 泪膜 显微镜检查/共焦 杯状细胞 前瞻性研究
在线阅读 下载PDF
上一页 1 2 142 下一页 到第
使用帮助 返回顶部 意见反馈