Assessing ecological risks of different valence states of Cr to marine organisms by species sensitivity distributions

应用生态风险评价中的物种敏感性分布(SSd)方法构建了3种不同形态(Cr、Cr3+、Cr6+)的重金属Cr对海洋生物的SSd曲线。在此基础上计算了3种形态的Cr对不同海洋生物的5%危害浓度(HC5)和其不同暴露浓度对海洋生物的潜在影响比例(PAf),比较了海洋脊椎动物和无脊椎动物对不同形态的重金属Cr的敏感性以及不同形态的Cr的急性生态风险,并且评价了两个港湾海水水体中常见形态的重金属Cr的联合生态风险。结果表明,3种形态的重金属Cr的HC5的大小顺序为Cr3+>Cr6+>Cr。浓度小于10μg/l时,Cr、Cr3+、Cr6+三者生态风险差异不大,且都处于相对较低的水平。在10μg/l的暴露浓度下,三者所影响的海洋生物比例均未超过5%。随着浓度升高,生态风险也相应增大。当浓度达到1 000μg/l时,分别有23.43%,13.73%和17.27%的物种受到Cr、Cr3+、Cr6+的损害,此时三者的生态风险差异也比低浓度时有所增大。当不同形态的重金属Cr浓度在不同的范围时,不同生物的敏感性大小顺序会发生变化。三种形态的重金属对无脊椎动物的生态风险均比脊椎动物(本文即指鱼类)大。两个海湾水体重金属生态风险的大小顺序为宁德海域(0.66%)>福清海域(0.63%)。Species sensitivity distributions(SSD) method was used to assess the ecological risk of three valence states of Cr(Cr,Cr3+,Cr6+) to marine organisms.The acute toxicity data(LC50 or EC50) were collected from ECOTOX database and SSD curves were fitted based on BurrIII and ReWeibull function.The acute ecological risks of different valence states of Cr and the sensitivity of different marine species(vertebrate and invertebrate) to these different valence states of Cr were compared by the hazardous concentrations for 5% of the species(HC5) and the potential affected fractions(PAF).Then the HC5 values of these different valence states of Cr were in the order:Cr3+> Cr6+> Cr.When exposure concentration was lower than 10 μg/L,no significant differences among the ecological risks of Cr,Cr3+ and Cr6+ was observed.Also,none of these four observations exceeded the threshold of 5%(PAF) at the exposure level of 10 μg/L.The ecological risks of the heavy metals increased as the exposure concentration increased.When came up to 1 000 μg/L,23.43%,13.73% and 17.27% of marine species would be affected by Cr,Cr3+ and Cr6+,respectively.The order of sensitivity to marine species varied with different concentration of heavy metals.The ecological risk of all these three valence states of Cr to invertebrate was higher than to fishes.The case studies showed that the ecological risk of different valence states of Cr in the Seas of Ningde was higher than that in the Seas of Fuqing.国家自然科学基金资助项目(31101902); 国家海洋局青年海洋科学基金资助项目(2011143); 海洋公益性行业科研专项经费资助(201105015); 福建省自然科学基金资助项目(2012J05074); 国家海洋局第三海洋研究所基本科研业务费专项资金资助项目(海三科2011006

自适应预测控制算法在转台设计中的应用

本文在分析了二轴仿真转台的经典控制方案基础之上，针对该二轴转台的时变工作方式，把自适应控制技术引入到方案中去，并在传统的反馈控制基础上增加了自适应前馈控制，同时推导出了自适应算法及系统稳定性条件。文章还针对微机控制系统的一步延迟及跟踪特性，提出了一种改善跟踪性能的新型预测算法－五点滤波法。通过理论分析、计算机仿真实验及实际应用，充分证明了本文提出的自适应预测控制算法（APC）的有效性

提高波前探测精度的高阶矩方法

<p> 夏克-哈特曼波前传感器测量畸变波前的探测精度主要取决于光斑质心的测量精度。提出了一种提高光斑质心探测精度的新方法,在优化的探测窗口内使用高阶矩方法计算光斑的质心。首先,在整个子孔径内,通过一阶矩方法获得光斑的近似中心,然后以这个近似中心为中心,包含整个光斑,建立一个矩形窗口,并在该窗口内通过高阶矩方法重新计算光斑的质心。通过该改进的方法,在优化的探测窗口外,噪声的影响基本被消除;在优化的探测窗口内,噪声的影响也因为光斑权值比重的增大而削弱。实验结果证明:与传统方法相比,新方法提高了光斑质心测量的精度、重复性和稳定性。</p

一种光照度不一致鲁棒立体匹配算法

为了提高光照度不一致立体图像对的匹配率,提出一种基于对数颜色空间下改进极线距离变换的立体匹配算法.在对数颜色空间下,首先根据初始视差图计算立体图像对的灰度比;然后,采用与灰度比成比例的灰度误差系数,分别对左右图像进行极线距离变换;最后利用置信度传播算法计算视差图.理论上,本文算法的匹配结果不会受光源位置、光源谱分布、光照强度以及摄像机参数设置等光照度不一致因素的影响.实验表明:本文算法的匹配率相对于原始极线距离变换算法最多可提高60%;而应用于弱纹理图像对时,相对于当前先进的自适应归一化算法,匹配率最多可提高78%

An adaptive wavelet transformation used on interference hyperspectral image compression

为了更好地提高干涉高光谱图像的压缩性能，针对干涉成像光谱仪的成像原理，提出了一种自适应方向预测提升小波变换的方法，在帧序列方向的提升小波变换中，以自适应方向获得最佳预测值，并且改变传统三维提升小波的变换顺序，消除大部分干涉条纹冗余，大量实验证明本文方法得到的高频子带小波系数相对于传统方法在指定码率的情况下重构图像可以获得更高的信噪比，恢复的光谱曲线具有更小的均方误差。 To get better performance of interference hyperspectral image compression, according to the imaging principle ofinterference hyperspectral image, we propose an adaptive direction prediction wavelet transform forLWT ( Lifting Wavelet Transformation ) , to get the best predicted values through adaptive direction in the LWT on the frame direction, and change the order of the traditional wavelet transform. The experiment results prove that the proposed method can get higher SNR at the same bpppb compared with the traditional method, and can get smaller MSE in the recovered spectral curve.To get better performance of interference hyperspectral image compression, according to the imaging principle ofinterference hyperspectral image, we propose an adaptive direction prediction wavelet transform forLWT (Lifting Wavelet Transformation), to get the best predicted values through adaptive direction in the LWT on the frame direction, and change the order of the traditional wavelet transform. The experiment results prove that the proposed method can get higher SNR at the same bpppb compared with the traditional method, and can get smaller MSE in the recovered spectral curve