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Chaotic systems have been intensively studied for their roles in many applications, such as cryptography, secure communications, nonlinear controls, etc. However, the limited complexity of existing chaotic systems weakens chaos-based practical applications. Designing chaotic maps with high complexity is attractive. This paper proposes the exponential sine chaotification model (ESCM), a method of using the exponential sine function as a nonlinear transform model, to enhance the complexity of chaotic maps. To verify the performance of the ESCM, we firstly demonstrated it through theoretical analysis. Then, to exhibit the high efficiency and usability of ESCM, we applied ESCM to one-dimensional (1D) and multi-dimensional (MD) chaotic systems. The effects were examined by the Lyapunov exponent and it was found that enhanced chaotic maps have much more complicated dynamic behaviors compared to their originals. To validate the simplicity of ESCM in hardware implementation, we simulated three enhanced chaotic maps using a digital signal processor (DSP). To explore the ESCM in practical application, we applied ESCM to image encryption. The results verified that the ESCM can make previous chaos maps competitive for usage in image encryption. 相似文献
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Two long-chain multidentate ligands: 2,9-di-(n-2',5',8'-triazanonyl)-1,10-phenanthroline (L^1) and 2,9-di- (n-4',7',10'-triazaundecyl)-1,10-phenanthroline (L^2) were synthesized. The hydrolytic kinetics of 2-hydroxypropyl p-nitrophenyl phosphate (HPNP) catalyzed by the complexes of L^1 or L^2 with La(Ⅲ) or Gd(Ⅲ) have been studied in aqueous solution at (298.2±0.1) K, I=0.10 mol·dm^-3 KNO3 in pH 7.5-9.1, respectively, finding that the catalytic effect of GdL^1 was the best among the four complexes for hydrolysis of HPNP. Its kLnLH-1, kLnLand pKa are 0.047 mol^-1·L·s^-1, 0.000074 mol^-1·L·s^-1 and 8.90, respectively. This paper expounded the studied result with the structure of the ligands and the properties of the metal ions, and deduced the catalysis mechanism. 相似文献
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分别以硅酸铝、分子筛、石墨、硅藻土、硅胶、中性氧化铝、二氧化锰为载体,制备了七种负载型KMnO4 (1a~1g).其结构经XRD表征.以1为氧化剂,马鞭草烯酮的碳碳双键完成氧化断裂反应,合成了一种重要的杀虫剂中间体低蒎酮酸(2),其结构经1H NMR和IR确证.合成2的较适宜反应条件为:马鞭草烯酮13.3mmol,1e... 相似文献
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系统地研究了氢还原重量法测定海绵钯灼烧损失量的条件,考察了非金属杂质元素含量对分析结果的影响,并将本法结果与热重法的测定结果进行对照。结果表明:1~2g样品,氢还原分段升温至800℃,重量法测定海绵钯中0.0019%,0.0142%,0.0302%和0.0694%灼烧损失量的极差、标准偏差(S)、相对标准偏差(RSD)和重复性限(r)分别为±0.0005%~0.0028%,0.0001%~0.0007%,1.0%~5.2%和0.0003%~0.0020%。灼烧损失量主要由氧、氮含量组成,碳含量对其影响忽略不计。方法结果准确、精密,且与热重法的分析结果吻合,能够满足99.90%~99.99%的海绵钯产品的分析要求。 相似文献
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FRP-混凝土-钢双壁空心管柱(FRP-concrete-steel double skin tubular columns)目前已在桥梁墩柱中得到应用,抗冲击性能是其推广应用的重要指标。为此,基于前期试验,采用ABAQUS软件建立了考虑轴力与侧向冲击耦合影响的有限元模型。首先,分析了轴力-冲击联合作用下该类构件的抗冲击机理;其次,重点研究了FRP厚度和缠绕角度、轴压比、冲击速度、空心率、内钢管径厚比与材料强度对抗冲击性能的影响;最后,给出了轴力-冲击耦合作用下构件动力放大系数的计算公式。结果表明,混凝土的塑性变形是构件抗冲击的主要耗能机制;轴力对构件抗冲击性能有明显影响,当轴压比大于0.7时,轴力对抗冲击性能有削弱作用;内钢管径厚比对构件抗冲击性能影响较小;建议的计算公式可较好地预测该类构件的抗冲击承载力。 相似文献
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建立了非等温、粘性、不可压缩、非牛顿流体流动的控制方程。为了避免同时求解耦合的压力场、速度场,本文通过修改Galerkin方法的变分方程,导出了关于压力场的拟Poisson方程,用迭代法独立地求解连续性方程、动量方程,并进行速度一粘度迭代求出最终的压力场、速度场。由于直接使用Galerkin方法求解能量方程容易引起温度场的振荡,本文采用隐式格式及“上风”法离散能量方程,用超松驰迭代法求解温度场的代数方程组。比较了模拟结果与等温管道流动的解析解及法兰的实际注射结果,算例表明本文方法可以预测注射成型流动过程中的一些重要特征。与传统Galerkin方法相比,本文方法可以减少内存,提高数值方法的稳定性。 相似文献
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在平衡单向分类模型中,通过对对照的三种同时置信区间长度表达式的分析,可以看到,在不同情况下,三种区间的优劣. 相似文献
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