A flux-controlled model of meminductor and its application in chaotic oscillator

A meminductor is a new type of memory device developed from the memristor.We present a mathematical model of a flux-controlled meminductor and its equivalent circuit model for exploring the properties of the meminductor in a nonlinear circuit.We explore the response characteristics of the meminductor under the exciting signals of sinusoidal,square,and triangular waves by using theoretical analysis and experimental tests,and design a meminductor-based oscillator based on the model.Theoretical analysis and experiments show that the meminductor-based oscillator possesses complex bifurcation behaviors and can generate periodic and chaotic oscillations.A special phenomenon called the co-existent oscillation that can generate multiple oscillations(such as chaotic,periodic oscillations as well as stable equilibrium) with the same parameters and different initial conditions occurs.We also design an analog circuit to realize the meminductor-based oscillator,and the circuit experiment results are in accordance with the theory analysis.     

L-丙交酯/ε-己内酯共聚物分子链结构非均匀性的研究

利用升温淋洗分级(TREF)和连续自成核退火热分级(SSA)等方法研究了L-丙交酯(LLA)和ε-己内酯(ε-CL)共聚物(PLC)分子链结构的非均匀性.合成了2种不同摩尔比的PLC共聚物,用TREF的方法,将同一个共聚物分级出3个级份.用核磁共振氢谱(1H-NMR)和凝胶渗透色谱(GPC)等方法对每个级份的分子结构进行了表征.结果表明,随着淋洗温度的升高,共聚物级份中的ε-CL单元的含量明显降低,而且级份的数均分子量增大,分子量分布指数降低.在SSA热分级研究中,发现PLC各级份间存在明显的分子链间和分子链内结构上的差异,这种链结构差异使得各个级份表现出不同的熔融行为.     

Cascade discrete memristive maps for enhancing chaos

Continuous-time memristor (CM) has been widely used to generate chaotic oscillations. However, discrete memristor (DM) has not been received adequate attention. Motivated by the cascade structure in electronic circuits, this paper introduces a method to cascade discrete memristive maps for generating chaos and hyperchaos. For a discrete-memristor seed map, it can be self-cascaded many times to get more parameters and complex structures, but with larger chaotic areas and Lyapunov exponents. Comparisons of dynamic characteristics between the seed map and cascading maps are explored. Meanwhile, numerical simulation results are verified by the hardware implementation.     

幅相同调的吸波-对消雷达散射截面减缩超表面设计

更宽的工作频带和更低的雷达散射截面(radar cross section, RCS)一直是低可探测领域研究的热点,然而这两者往往难以兼顾.鉴于此,本文提出了一种幅相同调的吸波-对消RCS减缩超表面,通过在宽带范围内同时设计两个单元的反射相位和反射幅度,使目标RCS在空间域和能量域分别获得10 d B以上减缩,从而通过叠加获得20 d B以上的宽带RCS减缩.仿真和实验结果表明,在两种极化下,幅相同调的吸波-对消RCS减缩超表面可以在6.10—12.15 GHz频带范围内获得20 d B以上的RCS减缩效果,同时10 d B减缩带宽为4.3—14.2 GHz.所设计的超表面具有减缩幅度大、减缩频带宽、质量轻、单层结构、极化稳定性好、柔性易共形等优点,有望为低可探测材料研制以及低可探测装备性能提升提供新的技术途径.     

基于尼罗红类ONOO-近红外荧光探针的开发及其成像应用

过氧亚硝酸根(ONOO^-)在氧化应激和炎症过程中的生成与细胞损伤、炎症反应和免疫调节等密切相关,因此,开发高灵敏且高度选择性的ONOO^-检测方法对于深入理解疾病发生和发展机制、提高疾病的早期诊断和治疗水平具有极其重要意义.设计合成了一种选择性检测ONOO^-的新型荧光探针NR-Pro.该探针通过使用烷基链将2-羟基尼罗红衍生物(NR-OH)与4,4’-氮杂二基二苯酚基团有机结合,在ONOO^-作用下,释放出近红外染料NR-OH.实验研究表明,该探针在658 nm处对ONOO^-表现出显著的“OFF-ON”型荧光信号响应,且对ONOO^-浓度在0～10μmol/L范围内呈现良好的线性关系,检出限低至17.7 nmol/L.这项研究进一步证实了NR-Pro探针在检测RAW264.7细胞中外源和内源ONOO^-方面具有优良的成像能力,这为早期诊断和治疗疾病提供了新的思路.