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基于回转器变换与非等模分解的光学加密算法
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作者 李培 朱春华 《太赫兹科学与电子信息学报》 2022年第5期470-478,共9页
为解决当前基于干涉的多图像密码系统中易出现轮廓和串扰噪声问题,设计了基于回转器(Gyrator)变换与非等模矢量分解的多彩色图像非对称光学加密算法。将所有彩色图像分解成红、绿、蓝三基色分量,再对每种颜色分类叠加,融合成三通道形式... 为解决当前基于干涉的多图像密码系统中易出现轮廓和串扰噪声问题,设计了基于回转器(Gyrator)变换与非等模矢量分解的多彩色图像非对称光学加密算法。将所有彩色图像分解成红、绿、蓝三基色分量,再对每种颜色分类叠加,融合成三通道形式;利用Logistic映射生成随机相位掩码,对叠加后的颜色分量进行调制处理。将调制后的图像分量分别在Gyrator变换域下进行旋转变换,形成3个复杂分布函数。利用非等模矢量分解方法,将其分解成振幅和相位均不相同的2个矢量,并将其中一个视为固定的共享矢量,另一个作为解密矢量。对共享矢量实施Gyrator逆变换,输出最终的密码图像。实验数据显示,较已有的多目标加密技术而言,该算法具备更强的抗破译能力,可以更好地解决串扰噪声问题。 展开更多
关键词 光学图像加密 LOGISTIC映射 Gyrator变换 等模分解 串扰噪声 共享矢量
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基于分阶Fourier频谱分解与混合随机掩码的光学加密算法 被引量:6
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作者 潘良 邱建林 《科学技术与工程》 北大核心 2019年第14期249-256,共8页
为了解决当前光学加密方法主要是借助普通相位掩码来调制初始图像,导致输出密文的安全性不理想的问题,通过融合Fresnel波带、Hilbert相位与混沌掩码,设计了分阶Fourier频谱分解与混合随机掩码的光学图像加密算法。首先,根据SHA-256哈希... 为了解决当前光学加密方法主要是借助普通相位掩码来调制初始图像,导致输出密文的安全性不理想的问题,通过融合Fresnel波带、Hilbert相位与混沌掩码,设计了分阶Fourier频谱分解与混合随机掩码的光学图像加密算法。首先,根据SHA-256哈希方法,形成一个256位的外部密钥,并将其分割为32个子密钥;引入二维Ushiki映射,利用子密钥来计算其初始条件,通过迭代来输出一组随机序列,从而构建一个混沌相位掩码;随后,引入Fresnel波带振幅与Hilbert相位函数,将二者与混沌相位掩码融合,形成一个混合掩码,兼顾其随机性与光轴校准精度;基于分阶Fourier变换,联合混合掩码,对初始明文完成光学调制,获取Fourier频谱;最后,通过等模分解方法来分割Fourier频谱,输出密文与私钥。测试数据表明:较已有的光学加密方案而言,所研究加密技术具备更理想的抗干扰能力与安全性,在噪声、剪切等攻击下,具有更为理想的解密质量。 展开更多
关键词 光学图像加密 二维Ushiki映射 混沌相位掩码 Fresnel波带 Hilbert相位函数 分阶Fourier变换 等模分解
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Reaction pathway and kinetics of CdO nanoparticles prepared from CdCO_3 precursor using thermal decomposition method
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作者 Gholam Reza KHAYATI Seyed Hadi SHAHCHERAGHI +1 位作者 Vahid LOTFI Esmael DAREZARESHKI 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2016年第4期1138-1145,共8页
The non-isothermal kinetics of CdO nanoparticles prepared from CdCO3 precursor using thermal decomposition method was investigated. A model-fitting Malek approach and a model-free advanced isoconversional method of Vy... The non-isothermal kinetics of CdO nanoparticles prepared from CdCO3 precursor using thermal decomposition method was investigated. A model-fitting Malek approach and a model-free advanced isoconversional method of Vyazovkin were applied to the analysis of the DSC and TGA data. The results showed that CdO nanoparticles prepared from CdCO3 followed an autocatalytic reaction. Sestak–Berggren model could favorably describe the studied reaction process. Moreover, the apparent activation energy of CdCO3 decomposition was calculated to be (119.19±9.97) kJ/mol and the explicit rate equation form of CdCO3 decomposition was established. 展开更多
关键词 CdCO_3 CdO nanoparticle kinetic modeling thermal decomposition advanced isoconversional method
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The Measurement of Carbon Emission Effect of Construction Land Changes in Anhui Province Based on the Extended LMDI Model 被引量:5
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作者 张乐勤 陈素平 +1 位作者 祝亚雯 许信旺 《Journal of Resources and Ecology》 CSCD 2013年第2期186-192,共7页
In the context of "two-wheel drive" development mode, China's construction land shows significant expansion characteristics. The carbon emission effect of construction land changes is an important factor for the in... In the context of "two-wheel drive" development mode, China's construction land shows significant expansion characteristics. The carbon emission effect of construction land changes is an important factor for the increase of carbon emissions in the atmosphere. In this study, the drivers of carbon emissions in Anhui Province from 1997 to 2011 were quantitatively measured using the improved Kaya identity and Logarithmic Mean Divisia Index. The results show that: economic growth, expansion of construction land and changes in population density have incremental effects on carbon emissions. The average contribution rate of economic growth as the first driver is 266.32 percent. The construction land expansion is an important driving factor with annual mean carbon effect of 6.4057 million tons and annual mean contribution rate of 187.30 percent. But the change in population density has little impact on carbon emission driving. Energy structure changes and energy intensity reduction have inhibitory effects on carbon emissions, of which the annual mean contribution rate is -212.06 percent and -158.115 percent respectively. The targeted policy approaches of carbon emission reduction were put forward based on the decomposition of carbon emission factors, laying a scientific basis to rationally use the land for the Government, which is conducive to build an ecological province for Anhui and achieve the purpose of emission reduction, providing a reference for the research on carbon emission effect of changes in provincial-scale construction land. 展开更多
关键词 construction land expansion carbon emission effect Kaya identity Logarithmic Mean DivisiaIndex decomposition model Anhui Province
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