共查询到19条相似文献,搜索用时 328 毫秒
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本文提出一种基于反向条纹投影原理的数字地球仪.在数字地球仪中,显示屏是一个球面的漫反射屏,通过投影的方法可以实现数字地球仪任意方向的旋转显示.首先通过投影正弦条纹到球面显示屏上,从观察数字地球仪的方向用CCD相机获取变形条纹图像,通过相移算法,建立投影器和摄像机像素之间的几何传递关系.基于地球三维图形信息数据库,根据期望图像为投影器产生投影图像.本文建立了地球三维信息提取模型,可快速获取从任意角度观察地球的图形信息.实验使用一半径为25 cm的漫反射球体作为显示屏,将计算得到反向地图投影其上,得到相当好的实验结果. 相似文献
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正一、引言柔性有机发光二极管~([1])(Flexible Organic Light Emitting Diodes,FOLED)是一项基于柔性衬底的自有光源显示屏技术,所述柔性衬底可以是柔性聚合物膜,金属薄片或者超薄玻璃。FOLED的制备过程一般包括如下步骤:在柔性衬底上涂覆作为阳极的氧化铟锡(Indiumtinoxide,ITO)透明导电膜,然后将有机发光和载流子传输材料以薄膜的 相似文献
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聚乙烯醇增塑体系的性能 总被引:3,自引:0,他引:3
用溶液共混的方法,向PVA中加入各种增塑剂及其复配体系,利用TGA、DSC、XRD等手段,研究了改性剂对PVA热性能及结晶的影响,利用熔体流动速率测定仪对加工性能进行了初步表征,同时分析了增塑剂加入对材料强度和断裂伸长率的影响。试验结果表明,改性体系的加入,降低了PVA的熔点和结晶度,分解温度有所提高;在满足材料强度的前提下,柔性得到很大改善,同时实现了PVA的熔融挤出。 相似文献
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综述了喷墨打印制备有机发光二极管显示屏(OLED)的发展历程。主要包括聚合发光二极管(PLED)的发明,喷墨打印法制备单色和全彩PLED显示屏及全彩有机发光显示屏(OLED)的研发3个主要阶段。较详细地介绍了国外为获得喷墨打印OLED显示屏核心工艺——高性能喷墨打印墨水配方和大面积阴极成膜工艺所开展的研究和取得的进展。对打印墨水配方和大面积阴极成膜工艺的细节作了详尽的描述。介绍了华南理工大学在研发了新的阴极界面材料的基础上,采用全溶液印刷工艺制备OLED显示屏的研究结果,并给出全溶液法OLED显示屏试验样品的详细数据。全溶法工艺无需真空热蒸镀金属工序,是喷墨打印制备OLED技术的一项重要进展。全溶液喷墨打印制备的OLED显示屏已在诸多方面获得应用,被证明具有工艺简单、成本低、低温工艺、可柔性弯曲等优点,适合于卷对卷规模化生产,但需要开发出更优质的阴极打印墨水和性能更高的阴极功能材料,才有可能采用全溶液法制备出大面积、出光效率更高的OLED显示屏,并进入工业化生产。 相似文献
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一直以来,科技场馆的胶片巨幕影院以70mm胶片放映为主,为科普事业发展做出了巨大贡献。但是,随着全球主流商业影院和电影节目内容创作生产的全面数字化,这些胶片巨幕影院面临着胶片放映的片源母版内容严重不足的问题,必须进行数字化改造和升级。本文从“科技场馆巨幕(胶片)影院向数字化放映转型的设备选择”、“科技场馆数字巨幕影院的母版DCP格式”、“面向科技场馆巨幕(数字)影院的数字巨幕影像制作技术及工艺流程研究”三个角度,以设计和实验的方法,提出了一套完整的解决方案和思路,供讨论研究。 相似文献
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推导出来的屏幕上点的斜面透视投影坐标式,完全满足计算机易于使用的参数方法的要求。用它编程,不但可以把正投影中点的坐标或曲线的参数方程转换成屏幕上能够直接显示点的透视投影的坐标或曲线的透视投影的参数方程,而且除了赋值不同外,对绘一点透视,二点透视和三点透视都具有通用性。此法与矩阵法相比,数学知识简单,易运用,特别是完全可以直接应用曲线的参数方程,更显示其优点。 相似文献
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It is recognized that packaging has a profound effect on the ultimate quality of food products reaching the consumer. So, the selection of proper packaging materials has become one of the major problems of the food technologist. In the field of flexible packaging one of the most important properties is water vapour/package interaction. Inverse gas chromatography has been used to study water sorption of polyvinylchlor-ide and poly(vinylidene chloride-vinylchloride) plasticized with different amounts of a polymeric plasticizer (poly(adipate ester)) at temperatures between 25°C and 50°C. It was found that the specific retention volume of water increases with decreasing temperature and increasing amount of plasticizer into the polymeric mixtures. The effect of temperature on water sorption behaviour is more pronounced compared with that of plasticizer addition. The thermodynamic parameters of water/polymer interaction, namely free energy, entropy, enthalpy and activity coefficient were calculated. Values were interpreted on the basis of an active-site absorption model. The Van Deemter equation was found to be applicable to these systems and was used to determine diffusion coefficients and activation energies for diffusion. Diffusion coefficient values increase with increasing amounts of plasticizer and this increase is accompanied by a decrease in the activation energy for diffusion. 相似文献
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柱面实像投影是飞机训练模拟器视景系统采用的主要投影方式之一,可以得到很大的观察视野,但是不可避免地会产生非线性失真。根据具体的工程背景,针对大视场角的柱面实像投影的非线性失真,分析了其产生的原因,并设计了投影仪的离轴安装方案,从而提出了基于预失真的柱面投影非线性失真校正算法。实际的校正结果表明,采用预失真的方法进行柱面非线性失真校正,是一种行之有效的方法。通过相应的数据结构设计,保证了程序执行的实时性。 相似文献
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激光投影显示中二次散射散斑抑制方法 总被引:1,自引:0,他引:1
在光学投影系统中,激光经各种元件散射后在投影屏上形成一次散射散斑,投影屏对激光的再次散射,经人眼成像后在视网膜上形成二次散射散斑.在激光投影系统的照明系统中,引入位相调制器调制照明光束,可抑制在投影屏平面上的一次散射散斑,和投影屏二次散射后在人眼视网膜上的二次散射散斑.通过简化的投影系统,对二次散射散斑形成和抑制进行了理论分析,获得了二次散射散斑抑制的条件和抑制后散斑衬度的规律,并进行了仿真和实验验证.理论结果表明,在一定条件下,一次散射散斑与二次散射散斑的衬度变化规律相同.对简化模型进行了仿真计算,得到在投影屏上的像面散斑衬度为0.0096,在探测器平面上的二次散射散斑的衬度为0.019,表明位相板调制投影系统照明光束能抑制一次散射散斑和二次散射散斑.对理论和仿真结果进行了实验验证. 相似文献
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Satturwar PM Fulzele SV Joshi SB Dorle AK 《Drug development and industrial pharmacy》2003,29(8):877-884
The film-forming and coating properties of a new biomaterial, hydrogenated rosin (HR), is investigated in the present communication. Films produced by casting method are studied for mechanical, (tensile strength, elongation, and Young's modulus), water vapor transmission, and moisture absorption characteristics. Type of plasticizer and its concentration were observed to play an important role in modifying the film characteristics. Dibutyl sebacate (DBS), a hydrophobic plasticizer, was found to be suitable for development of flexible and smooth films. Film formulations plasticized with DBS were investigated for coating the drug layered nonpareil seeds where plasticization facilitated development of smooth and uniformly coated pellets. The increase in coat buildup, however, did not sustain the drug release significantly. The studies conclude that HR films promise utility as moisture-protective hydrophobic, film-coating materials. 相似文献
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We describe a way to display three-dimensional images by integral imaging using an ordinary projector. We first explain a method that uses a large-aperture converging lens, then we explain the proposed method that uses two sets of lens array. Based on the principle of this new approach, front projection as well as rear projection is possible. Only a proper viewing area can be formed on the optical screen by this method, which improves the brightness of images on the screen. The projector itself does not need an additional optical system. We report on the results of an experiment carried out to confirm the validity of the proposed method. 相似文献