4-aperture differential image motion monitor as a new approach for estimating atmospheric turbulence parameters

The present study aims to evaluate the possibility of simultaneous measurements of Fried parameter and atmospheric Zernike defocus by measuring defocus aberration with 4-aperture differential image motion monitor (DIMM) for a portable telescope. Based on the results, a relation was observed between the variances of the defocus aberration (4-aperture defocus) and Fried parameter for G-tilt and Z-tilt methods. In addition, the variance of the 4-aperture defocus was compared with those of the Zernike defocus and the conventional DIMM and the results indicated a linear relationship. Based on the telescope and 4-aperture specifications, the variance of the 4-aperture defocus was converted into the Zernike defocus or the DIMM variances. Finally, the ability of estimating atmospheric coherence time by measuring the variance of the Zernike defocus velocity or the sum of the variances of two astigmatisms velocities with 4-aperture DIMM was investigated.     

即食调味鲅鱼产品开发及杀菌条件对其品质的影响

为开发一款即食调味鲅鱼产品,通过正交优化确定调味鲅鱼的最佳调味料配方,同时探究不同杀菌条件对产品品质的影响。结果表明:最佳调味配方为白砂糖添加量1 g,辣椒粉添加量2 g,麻椒油添加量2 g,五香粉添加量1.5 g;杀菌条件对调味鲅鱼质构和色差中的硬度、胶着度、咀嚼度和L值影响显著,当杀菌条件为115℃、20 min时,鲅鱼硬度为1405.33±45.30,L值为58.52±0.41,综合感官评分最高。结合菌落总数、感官评价、质构和色差综合分析,最佳杀菌条件为:115℃、20 min。     

基于染色体畸变的细胞存活模型研究

为评估质子和重离子的辐射生物效应，建立了基于染色体畸变的细胞存活机理模型。开发了纳剂量生物物理蒙特卡罗模拟程序（NASIC）的DNA损伤修复模块，用于模拟不同射线类型、不同传能线密度（LET）辐射所致细胞核内染色体畸变产额。在分析辐射所致染色体畸变产额规律的基础上，建立了基于染色体畸变的细胞存活机理模型，并根据细胞存活实验数据拟合模型参数。以V79细胞为例，对于X射线和不同LET的质子，细胞存活分数的模型计算值与实验数据符合得很好，相关系数为0.985 3。采用⁴He离子的实验数据对模型及参数进行了验证，模型计算值与实验数据的相关系数为0.931 1。可见，模型能较好地区分不同射线类型、不同LET辐射在细胞致死效应上的差异。     

Fuzzy Based Hybrid Focus Value Estimation for Multi Focus Image Fusion

Due to limited depth-of-field of digital single-lens reflex cameras, the scene content within a limited distance from the imaging plane remains in focus while other objects closer to or further away from the point of focus appear as blurred (out-of-focus) in the image. Multi-Focus Image Fusion can be used to reconstruct a fully focused image from two or more partially focused images of the same scene. In this paper, a new Fuzzy Based Hybrid Focus Measure (FBHFM) for multi-focus image fusion has been proposed. Optimal block size is very critical step for multi-focus image fusion. Particle Swarm Optimization (PSO) algorithm has been used to find optimal size of the block of the images for extraction of focus measure features. After finding optimal blocks, three focus measures Sum of Modified Laplacian, Gray Level Variance and Contrast Visibility has been extracted and combined these focus measures by using intelligent fuzzy technique. Fuzzy based hybrid intelligent focus values were estimated using contrast visibility measure to generate focused image. Different sets of multi-focus images have been used in detailed experimentation and compared the results with state-of-the-art existing techniques such as Genetic Algorithm (GA), Principal Component Analysis (PCA), Laplacian Pyramid discrete wavelet transform (DWT), and aDWT for image fusion. It has been found that proposed method performs well as compare to existing methods.

     

Cytotoxic effect of sodium arsenite on Nile tilapia (Oreochromis niloticus) in vivo

This study showed the relevance of using chromosomal aberration (CA) as potential indicators of sodium arsenite (SA; NaAsO₂) cytotoxicity. The study investigated cytotoxic potential of SA in Oreochromis niloticus using CA assessment. The fish were exposed to four different concentrations of SA (5, 10, 20 and 40 mg/L) for 24 hours in comparison to a control group. The As concentrations in the samples were analysed by inductively coupled plasma atomic emission spectrometry. The differences in As concentrations in the water and O. niloticus samples between the control and experimental groups were significant (p<0.05), whereas the within experimental group differences were not significant. The cytotoxic assessment of SA in O. niloticus revealed five types of CAs, including single chromatid gaps (SCG), single chromatid break (SCB), centric gap (CG), fragmentation (F) and deletion (D). The most common CA in the O. niloticus samples was SCG. A total of 2.33, 10.67, 18.67, 18.00 and 23.67% of the cells in the control and experimental groups exhibited CAs. The numbers of CAs and cells with CAs from the control and experimental groups of fish were significantly different (p<0.05); additionally, the fish exposed to 5 and 40 mg/L showed significant within experimental group differences (p<0.05).     

Quality assessment for color correction-based stitched images via bi-directional matching

With the deepening of social information, the panoramic image has drawn a significant interest of viewers and researchers as it can provide a very wide field of view (FoV). Since panoramic images are usually obtained by capturing images with the overlapping regions and then stitching them together, image stitching plays an important role in generating panoramic images. In order to effectively evaluate the quality of stitched images, a novel quality assessment method based on bi-directional matching is proposed for stitched images. Specifically, dense correspondences between the testing and benchmark stitched images are first established by bi-directional SIFT-flow matching. Then, color-aware, geometric-aware and structure-aware features are respectively extracted and fused via support vector regression (SVR) to obtain the final quality score. Experiments on our newly constructed database and ISIQA database demonstrate that the proposed method can achieve comparable performance compared with the conventional blind quality metrics and the quality metrics specially designed for stitched images.     

精密光学系统的热像差

为了精确控制与补偿物镜的热像差,设计了一套三镜实验光学系统,基于该系统验证了热像差计算方法的准确性。介绍了热像差分析方法及验证实验方案。开展不同热载工况下热像差测试实验,并与仿真结果进行了对比。最后,综合实验与仿真结果,分析了特定热载条件下系统热像差中非轴对称像差成分以及系统最佳焦面的变化趋势,获得了热像差的瞬态特性。实验结果显示:在输入热载大小之比为1∶4∶9的情况下,实验和仿真获得的热像差均方根(RMS)值之比分别为1∶3.75∶9和1∶4.01∶9.01,光学系统所加热载和热像差之间呈线性关系;在实验热载荷作用下,系统最佳焦面的稳态时间小于450min,而热像差中一阶像散(标准Zernike Z4)的稳态时间小于48min,一阶四叶(标准Zernike Z11)的稳态时间小于9min,最佳焦面稳态时间远大于非轴对称成分的稳态时间。基于该三镜实验光学系统所获得的热像差特性能够为投影光刻物镜或其它精密光学系统的热像差控制与补偿提供有力支撑。     

主三镜一体化离轴三反光学系统设计

离轴三反光学系统具有成像质量高、可实现大视场、无遮拦等优点,但其装调难度大,镜面支撑结构质量大。为解决这些问题,基于三级像差理论,研究一种主镜、三镜可集成一体化的大视场离轴三反光学系统,并以焦距为1 200 mm,F数为12,视场为101的光学系统为例进行了验证设计。结果表明:调制传递函数接近衍射极限,视场内平均波像差RMS值为/55,最大波像差RMS值为/22。设计结果显示,光学系统装调自由度由12个减少到6个,可使光机系统可得到简化,实现了主三镜一体化设计。     

基于波前像差的图像质量评价方法研究

图像质量评价的研究已成为图像信息工程的基础技术之一。由于图像的最终接受者是人,所以评价图像质量应反映出人类的主观视觉感知。为构造一种符合人眼视觉特性的图像质量评价方法,利用点扩散函数针对人眼建立了含有波前像差信息的图像视觉评价模型,并用此模型分别对添加不同噪声的图像进行图像质量评价。实验结果表明,该方法是可行的、有效的,不同的人眼对同一幅图像的评价存在有差异,人眼波前像差越小观察到的图像越清晰。该方法不仅能够在评价图像质量时准确反映人眼的主观感知,而且能够直观地呈现不同人眼实际看到的图像。     

Genotoxicity of recycling electronic waste in Idhna,Hebron District,Palestine

Most Electronic waste (e-waste) ends up in landfills while some is recycled. A major site for e-waste recycling in Palestine is the village of Idhna in the Hebron District and most of this waste originates from Israel. The objective of this study was to evaluate the effects of e-waste on human DNA damage and chromosome breaks. The test sample was 46 non-smoker individuals with direct exposure to e-waste, either employed in the workshops or resident in Idhna. Genotoxicity data were compared with a control sample of sixteen unexposed individuals from Bethlehem and Al-Aizariya (Bethany). DNA damage was evaluated using the Comet assay while chromosome aberrations were tested by using conventional cytogenetic techniques. We noted an average of 4.83 aberration/cell/subject in test samples while in controls the average was 0.75. Chromosome aberration frequency was statistically different between exposed and control samples for total aberrations, for chromatid and chromosome breaks, and for formation of rings but not for dicenterics and tetraploidy. The Comet assay likewise showed that there was significant difference between exposed and control samples for DNA damage (p < 0.05). We therefore recommend measures to mitigate the health impact of e-waste recycling.