A method of estimating initial conditions of coupled maplattices based on time-varying symbolic dynamics

A novel computationally efficient algorithm in terms of the time-varying symbolic dynamic method is proposed to estimate the unknown initial conditions of coupled map lattices (CMLs). The presented method combines symbolic dynamics with time-varying control parameters to develop a time-varying scheme for estimating the initial condition of multi-dimensional spatiotemporal chaotic signals. The performances of the presented time-varying estimator in both noiseless and noisy environments are analysed and compared with the common time-invariant estimator. Simulations are carried out and the obtained results show that the proposed method provides an efficient estimation of the initial condition of each lattice in the coupled system. The algorithm cannot yield an asymptotically unbiased estimation due to the effect of the coupling term, but the estimation with the time-varying algorithm is closer to the Cramer--Rao lower bound (CRLB) than that with the time-invariant estimation method, especially at high signal-to-noise ratios (SNRs).     

PEDOT:PSS/ZnPc作为有机小分子太阳电池阳极修饰层的研究

采用阳极修饰法构建了基于酞菁铜(CuPc)和碳60(C60)的有机小分子太阳电池,分别研究了酞菁锌(ZnPc)、聚苯乙烯磺酸(PEDOT:PSS)和PEDOT:PSS/ZnPc作为阳极修饰层对该有机太阳电池输出性能的影响,并对三种修饰层的相关机理进行了探讨.结果表明:加入ZnPc修饰层的电池开路电压(Voc)增大,从0.372提高到0.479 V.旋涂PEDOT:PSS的电池短路电流(Jsc)提高,由1.943 mA/cm2提高到3.752 mA/cm2.而以PEDOT:PSS/ZnPc作为阳极修饰的电池Voc和Jsc均有较大的提高,Voc从 0.372 V提高到0.482 V,Jsc从1.943 mA/cm2提高到3.810 mA/ cm2,其转换效率可提高两倍以上.分析认为,ZnPc更有利于阳极空穴的输出,PEDOT:PSS能有效改善ITO表面的平整度的性质是提高太阳电池性能的主要原因.     

单边磁共振成像仪磁体系统研究

单边磁共振成像（MRI）系统由于其良好的开放性引起了越来越多的关注,这种系统的成像样品区位于磁体外侧,其形状为薄片形,其磁体结构设计是一个全新的问题. 本文基于鞍点理论,探索这种单边磁体在其外侧产生均匀样品区的可行性,通过对几种单边磁体结构磁场特性的研究,指出适当设计的永磁磁体能够在磁体外侧产生鞍点. 最后给出一种符合成像要求的单边永磁MRI磁体结构. 单边MRI磁体结构的可行性分析及磁体结构的成功设计,为开展完全开放式磁共振成像装置的研究打下了坚实的基础.     

某些导电高分子的波谱性能

本文以聚吡咯和聚噻吩为例，对导电高分子的紫外－可见光谱、红外光谱、远红外及微波区的波谱性能进行了综述，并分析了波谱性能与结构的关系。对导电高分子波谱性能的实际应用前景也进行了论述。     

油滴实验和偏倚期盼现象

提供了关于元电荷测试、有关密立根油滴实验以及其中数据处理的争议点的历史研究若干线索.简要介绍了一些相关文献,希有助于初涉这段历史的读者迅速接触核心.对可能长期存在的偏倚期盼现象作了较多摘引以期引起关注.     

Two Superconducting Phases and Their Characteristics in Layered BaTi2（Sb1-xBix）2O with x=0.16

Two correlated superconducting phases are identified in the layered superconductor BaTh （Sb1-xBix）2O （x = 0.16）, with the superconducting transition temperatures of Tc = 6K （the high Tc phase） and 3.4K （the low Tc Phase）, respectively. The 6K superconducting phase appears first in the as-prepared sample and can decay into the low TC phase by exposure to an ambient atmosphere for a certain duration. Specially, the high Tc phase can reappear from the decayed sample with the low Tc phase by vacuum annealing. It is also found that the CDW /SDW order occurs only with the 6 K superconducting phase. These notable features and alteration of the superconductivity due to the post-processing and external pressure can be explained by the scenario of electronic phase separation.