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1.
Diverse functionalities of liquid crystals (LCs) offer enormous opportunities for their potential use in advanced mobile and smart displays, as well as novel non-display applications. Here, we present snapshots of the research carried out on emerging applications of LCs ranging from electronics to holography and self-powered systems. In addition, we will show our recent results focused on the development of new LC applications, such as programmable transistors, a transparent and active-type two-dimensional optical array and self-powered display systems based on LCs, and will briefly discuss their novel concepts and basic operating principles. Our research will give insights not only into comprehensively understanding technical and scientific applications of LCs, but also developing new discoveries of other LC-based devices.  相似文献   
2.
Aberrations in optical microscopy reduce image resolution and contrast, and can limit imaging depth when focusing into biological samples. Static correction of aberrations may be achieved through appropriate lens design, but this approach does not offer the flexibility of simultaneously correcting aberrations for all imaging depths, nor the adaptability to correct for sample-specific aberrations for high-quality tomographic optical imaging. Incorporation of adaptive optics (AO) methods have demonstrated considerable improvement in optical image contrast and resolution in noninterferometric microscopy techniques, as well as in optical coherence tomography. Here we present a method to correct aberrations in a tomogram rather than the beam of a broadband optical interferometry system. Based on Fourier optics principles, we correct aberrations of a virtual pupil using Zernike polynomials. When used in conjunction with the computed imaging method interferometric synthetic aperture microscopy, this computational AO enables object reconstruction (within the single scattering limit) with ideal focal-plane resolution at all depths. Tomographic reconstructions of tissue phantoms containing subresolution titanium-dioxide particles and of ex vivo rat lung tissue demonstrate aberration correction in datasets acquired with a highly astigmatic illumination beam. These results also demonstrate that imaging with an aberrated astigmatic beam provides the advantage of a more uniform depth-dependent signal compared to imaging with a standard gaussian beam. With further work, computational AO could enable the replacement of complicated and expensive optical hardware components with algorithms implemented on a standard desktop computer, making high-resolution 3D interferometric tomography accessible to a wider group of users and nonspecialists.  相似文献   
3.
The nopal cactus (Opuntia ficus-indica) releases a substance through its mucilage, which comes from the degradation of pectic substances and chlorophyll. Combined in a polyvinyl alcohol matrix, this substance can be used as a recording medium. The resulting extract material has excellent photosensitizer properties, is easy to handle, has a low cost, and low toxicity. This material has the property of self-developing, and it can be used in holographic applications. The polyvinyl alcohol and extract from the nopal cactus was deposited by a gravity technique on a glass substrate, which dried to form a photosensitive emulsion. We show experimental results on a holographic grating using this material, written by a He-Cd laser (442 nm). We obtained diffraction gratings by transmission with a diffraction efficiency of approximately 32.3% to first order.  相似文献   
4.
目的评价全息影像技术引导机器人辅助腹腔镜下肾部分切除术(RAPN)治疗肾门部肿瘤的可行性与有效性。方法回顾性分析该院2019年6月-2019年10月收治的11例肾门部肿瘤患者的临床资料。其中,男3例,女8例;左侧4例,右侧7例;患者年龄32~75岁,平均62.6岁,体质指数19.45~28.12 kg/m^2,平均23.75 kg/m^2,肿瘤直径1.1~6.7 cm,平均2.76 cm,R.E.N.A.L.评分8~12分,平均10.7分,患肾肾小球滤过率(GFR)22~51 mL/min,平均35 mL/min。患者术前行全腹部增强CT,利用CT数据进行全息影像重建。术中应用该技术结合达芬奇机器人辅助系统,精准分离、剜除肿瘤,并记录手术持续时间、出血量、肾脏热缺血时间、有无并发症及切缘阳性率等。结果根据全息影像引导,11例患者均顺利剜除肿瘤,完成手术,无中转开放。手术时间60~130 min,平均90 min。术中出血量50~180 mL,平均100 mL,热缺血时间18~25 min,平均21 min,无术后发热、继发出血或漏尿等并发症。术后病理诊断肾透明细胞癌9例(FuhrmanⅠ和Ⅱ级),乳头状细胞癌1例,血管平滑肌脂肪瘤1例,无切缘阳性病例。术后随访3~7个月,平均4.3个月,患肾GFR 18~43 mL/min,平均31 mL/min。术后3个月复查肾脏CT平扫及增强,全部患者未出现复发。结论全息影像技术引导RAPN治疗肾门部肿瘤,围手术期并发症少,安全有效。  相似文献   
5.
同步辐射类同轴技术应用于肾脏成像的实验研究   总被引:1,自引:1,他引:1       下载免费PDF全文
目的 应用同步辐射光源的相干性,进行肾脏组织的类同轴成像研究,旨在评价相位衬度成像技术在软组织成像方面的意义.方法 在北京同步辐射装置形貌站4W1A束线上,取经过4%甲醛溶液固定后的人体肾脏组织样品,置于类同轴光路的样品架上进行成像,以空间分辨率和组织衬度作为评价标准.结果 在样品与成像板距离Z为150 mm时获得的肾脏成像,具有较高的组织衬度,包括肾小囊在内的结构均能较好显示,通过显微放大法获得的空间分辨率达到30 μm.结论 类同轴技术能较好显示肾脏的微细解剖结构,对于以轻元素为主的脏器成像有较好的应用价值.  相似文献   
6.
超声诊断仪新技术的发展   总被引:1,自引:1,他引:1  
目的:超声影像技术与X-CT、核素扫描、磁共振成像一起被公认为现代医学的四大影像技术,其技术发展非常迅猛。本文主要介绍了超声诊断仪在成像技术、多维超声技术和全息超声技术等方面的新进展。  相似文献   
7.
A new holographic technique is utilized to obtain in vivo three dimensional photographic records. The development of a holographic endoscopic camera (endoholoscope or holocamera) provides a unique method of diagnosis of internal organs and tissues. A hologram of the larynx of an anesthetized dog shows details which could not be observed by indirect laryngoscopy.  相似文献   
8.
9.
Photorefractive materials are capable of reversibly changing their index of refraction upon illumination. That property allows them to dynamically record holograms, which is a key function for developing an updateable holographic 3D display. The transition from inorganic photorefractive crystals to organic polymers meant that large display screens could be made. However, one essential figure of merit that needed to be worked out first was the sensitivity of the material that enables to record bright images in a short amount of time. In this review article, we describe how polymer engineering was able to overcome the problem of the material sensitivity. We highlight the importance of understanding the energy levels of the different species in order to optimize the efficiency and recording speed. We then discuss different photorefractive compounds and the reason for their particular figures of merit. Finally, we consider the technical choices taken to obtain an updateable 3D display using photorefractive polymer. By leveraging the unique properties of this holographic recording material, full color holograms were demonstrated, as well as refreshing rate of 100 hogels/second.  相似文献   
10.
以光引发阻聚剂、光聚合单体和离子液体1-丁基-3-甲基咪唑啉双(三氟甲基磺酰基)亚胺组成的混合液为原料,通过激光全息曝光,制备了透射式全息聚合物分散离子液体(HPDIL)。研究了离子液体质量分数对体系黏度、光聚合反应动力学、相分离程度、HPDIL光学性能及导电特性的影响。结果表明:当离子液体质量分数从0.2增加至0.6时,体系黏度从6.9 mPa·s升高至25.3 mPa·s,光照1 200 s后的双键转化率从39%降低至18%。随着离子液体质量分数的增加,HPDIL的衍射效率先升高后降低。当离子液体质量分数为0.6时,HPDIL的衍射效率达到峰值70.5%,折射率调制度达到12.3×10-3。当离子液体质量分数为0.5时,体系的相分离程度达到峰值38.2%。HPDIL具有导电各向异性,当离子液体质量分数为0.6时,HPDIL条纹平行方向的电导率可达垂直方向电导率的2.7倍。  相似文献   
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