位置与波长并行复用技术下的光学干涉多图像加密系统(英文)

基于位置和波长参量的并行复用,提出一种高加密容量的光学干涉多图像加密系统.加密时,待加密图像分为两组,每组均利用位置复用技术解析地加密到两个纯相位板中,将所获取的四个相位板再经波长复用技术融合到两个光学相位元件中.加密过程采用数字技术,无需使用迭代算法,而解密过程既可以采用数字技术也可以采用纯光学方法.实验中利用波长与位置的并行复用及相关系数对系统的加密容量进行评估,同时研究了系统对于噪音攻击和剪切攻击的稳健性.结果表明:加密容量较已有方法有较大提高;对于噪音攻击的稳健性较强,但是对于剪切攻击的稳健性较弱.     

相位板装配倾斜对波前编码系统点扩散函数的影响

分析了装配误差引起的相位板倾斜对波前编码系统的影响,通过坐标变换推导了相应条件下的广义光瞳函数。结果表明：倾斜因子对系统的相位板系数具有放大效果,其随倾斜角绝对值的增大而增大,而与倾斜角的正负无关。相位板倾斜会放大系统点扩散函数包络面的两条直角边,相应地降低其光学传递函数值。在子午倾斜的条件下,子午方向的相位板系数放大效果大于弧矢方向,从而导致点扩散函数包络面在子午方向的放大效果大于弧矢方向,子午方向光学传递函数值的降低效果大于弧矢方向。采用MATLAB以及商用光学软件进行仿真实验,验证了上述结论。     

Self assembled micro masking effect in the fabrication of SiC nanopillars by ICP-RIE dry etching

This report presents the results of the novel fabrication of 4H-SiC pillars with nanopores using ICP-RIE dry etching. Cl₂/Ar gas plasma with various mass flow rates was used in this etching process to produce SiC nanopillars without using patterned etch mask. Cylindrical pillars of 300 nm diameter and 500 nm height with smooth side walls were etched on SiC wafer. The etching condition for the optimized fabrication of SiC nanopillars is presented in this report. Each nanopillar has been produced with a nanosize pore at the center along its length and up to the middle of the cylindrical nanopillar; it is a unique feature has not ever been reported in case of SiC. Inclusion of oxygen was found influence the formation of nanopillars by the effect of SiO₂ micro masking. The formation of self assembled SiO₂ layer and its micro masking effect in the fabrication of this unique nanostructure has been investigated using TEM, STEM and EDAX measurements.     

Enhanced control release of thyme essential oils from electrospun nanofiber/polyamidoamine dendritic polymer for antibacterial platforms

The motive of the present investigation is to probe the role of polyamidoamine dendritic polymer (PAMAM) as a nano‐carrier function on the stepwise‐release rate of thyme oil (TEO) as natural extract with a superior antibacterial property. To represent quantitative and kinetic trends of release from nylon 6 electrospun fiber mats of TEO from mats, single‐sensor gas diagnosis device as an applicable diagnostic tool was tested in a distinct time sheet. All mats were characterized using scanning electron microscopy (SEM), Fourier‐transform infrared spectroscopy (FTIR), surface tension, contact angle, and antibacterial activity. As an outcome, PAMAM is major responsible for the pretending burst release due to the remarkable branches and cavities of PAMAM which encapsulate TEO. Noticeably, long‐term exposure of TEO was reached compared to the counterpart sample and a higher amount of PAMAM renders further functionality to protect guest molecules and not let them move easily in the atmosphere. It is realized that the essence release of mats with 2 and 10 wt% of PAMAM moieties last up to 9 and 12 days, respectively. Interestingly, all functionalized samples prevent the growth of Escherichia coli and Staphylococcus aureus bacteria and antibacterial value for samples with PAMAM surpassed 100% while decreased around 15 to 50% for mats without PAMAM over a 2‐week period. The results revealed that the functionalized samples were a promising fragrance delivery system with more effective antibacterial activity.     

超分辨技术在光盘中的应用研究

超分辨技术是一种无需用减小波长或增大数值孔径的方法减小记录点尺寸而能读出超过衍射极限信号从而有效增加存储密度的一种方法，超分辨可以通过调整光学系统或者调整光盘的结构来实现，在超分辨光盘中，超分辨是基于掩膜的光学性质随入射激光强度的非线性变化而实现的，在磁光盘中第一次引入超分辨技术后，超分辨技术的应用有了很大发展，在目前是提高光盘存储密度的有效方法，在各类光盘中都有良好的应用，近场超分辨技术的出现使相变光盘的超高密度记录和读出成为可能，文章综述了超分辨光盘的发展现状和发展方向。     

体全息存储中输入方参数对输出信号的影响

借助基于 4F成像系统的掩模版模拟SLM实验 ,在国内首次实现 10 0 0× 10 0 0高分辨率数据页输入 输出像素一对一匹配的基础上研究了体全息存储系统输入方重要参数 ,如 :输入器件 (空间光调制器 )像素填充因子和输入图案组合对输出器件 (电荷耦合器件 )读出图像的影响 ,为提高全息存储系统输出图像质量、降低误码率提供理论和实验基础。     

Microstructures of patterned nc-Si superlattices made by pulsed laser interference crystallization

We employed atomic force microscopy, cross-section transmission electron microscopy and high-resolution electron microscopy to investigate the microstructures and surface morphology of laser interference crystallized a-Si : H/a-SiN_x : H superlattices. The experimental results show that Si nanocrystallites (nc-Si) are formed within the initial a-Si : H sublayers and are patterned in certain regions with the same periodicity of 2.0 μ m as the phase-shifting mask grating. The size of nc-Si is limited by adjacent a-SiN _x: H sublayers due to the constrained crystallization effect so it is possible to use this crystallization method to get a three-dimensional ordered nc-Si array.     

Fabrication and integration of planar electrodes for contactless conductivity detection on polyester-toner electrophoresis microchips

In this report, we describe the microfabrication and integration of planar electrodes for contactless conductivity detection on polyester-toner (PT) electrophoresis microchips using toner masks. Planar electrodes were fabricated by three simple steps: (i) drawing and laser-printing the electrode geometry on polyester films, (ii) sputtering deposition onto substrates, and (iii) removal of toner layer by a lift-off process. The polyester film with anchored electrodes was integrated to PT electrophoresis microchannels by lamination at 120 degrees C in less than 1 min. The electrodes were designed in an antiparallel configuration with 750 microm width and 750 microm gap between them. The best results were recorded with a frequency of 400 kHz and 10 Vpp using a sinusoidal wave. The analytical performance of the proposed microchip was evaluated by electrophoretic separation of potassium, sodium and lithium in 150 microm wide x 6 microm deep microchannels. Under an electric field of 250 V/cm the analytes were successfully separated in less than 90 s with efficiencies ranging from 7000 to 13,000 plates. The detection limits (S/N = 3) found for K+, Na+, and Li+ were 3.1, 4.3, and 7.2 micromol/L, respectively. Besides the low-cost and instrumental simplicity, the integrated PT chip eliminates the problem of manual alignment and gluing of the electrodes, permitting more robustness and better reproducibility, therefore, more suitable for mass production of electrophoresis microchips.     

测试因素对一次性医用口罩通气阻力的影响

针对一次性医用口罩(DMMs)通气阻力测试结果不稳定情况,从测试设备稳定性、气体流量、样品不同位置、气流方向、预处理、测试时间方面展开了研究。结果表明,气体流量、样品不同位置和预处理对口罩的通气阻力有较大影响,测试时间和气流方向对口罩通气阻力无明显影响。研究结果对各生产厂商开发优异DMMs及生产过程质量控制有重要意义。     

波前编码系统景深延拓性能研究

波前编码景深延拓技术是在非相干光学系统的出瞳处加入三次位相板,对成像进行解码处理而获得清晰图像以扩大光学系统景深的技术.文章通过深入研究波前编码光学成像系统的调制传递函数(MTF),分析离焦量和位相板的调制系数对MTF的影响,并通过数值计算和曲线拟合得到位相板调制系数、系统带宽、景深延拓性能之间的关系.该研究成果为位相板的调制系数的选择和景深延拓光学系统的设计提供依据. 关键词： 波前编码 景深延拓 调制传递函数 三次位相板