Blind Frequency Estimation and Symbol Recovery for the Analytically Solvable Chaotic System.

The analytically solvable chaotic system (ASCS) is a promising chaotic system in chaos communication and radar fields. In this paper, we propose a maximum likelihood estimator (MLE) to estimate the frequency of ASCS, then a difference-integral (DI) detector is designed with the estimated frequency, and the symbols encoded in the signal are recovered. In the proposed method, the frequency parameter is estimated by an MLE based on the square power of the received signal. The Cramer-Rao lower bound in blind frequency estimation and the bit error performance in symbol detection are analyzed to assess the performance of the proposed method. Numerical results validate the analysis and demonstrate that the proposed symbol detector achieves the error performance with a little cost of 1 dB compared to the coherent detector. The robustness of the proposed method towards parameters is also verified through simulations.

N,N-Di-phenyl-4-(1H-pyrrolo[1,2-f][1,10]phenanthro-lin-2-yl)-aniline ethanol monosolvate.

The title compound, C32H21N4·C2H5OH, crystallized as an ethanol monosolvate. In the mol-ecule of this phenanthroline derivative, the pyridine rings are almost coplanar, making a dihedral angle of 1.54 (13)°. The tri-phenyl-amine group, introduced as an electron donor, shows a propeller-type structure, and the dihedral angles between the benzene rings are 68.71 11), 63.92 (16) and 70.81 (15)°. In the crystal, the phenanthroline mol-ecules are linked via the solvent mol-ecule by N-H⋯O, O-H⋯N and C-H⋯O hydrogen bonds, leading to the formation of zigzag chains propagating along [010]. These chains are linked via C-H⋯N hydrogen bonds, forming undulating two-dimensional networks extending in the a- and b-axis directions.

{9-Hexyl-2-[2-phenyl-6-(pyridin-2-yl)pyridin-4-yl]-9H-carbazole}di-iodido-zinc.

In the title compound, [ZnI2(C34H31N3)], the Zn(II) atom is four-coordinated by two I atoms and the pyridine N atoms from the bidentate 6'-phenyl-2,2'-bi-pyridine ligand in a distorted tetra-hedral geometry.

Synthesis, spectral and third-order nonlinear optical properties of terpyridine Zn(II) complexes based on carbazole derivative with polyether group.

Four novel Zn(II) terpyridine complexes (ZnLCl2, ZnLBr2, ZnLI2, ZnL(SCN)2) based on carbazole derivative group were designed, synthesized and fully characterized. Their photophysical properties including absorption and one-photon excited fluorescence, two-photon absorption (TPA) and optical power limiting (OPL) were further investigated systematically and interpreted on the basis of theoretical calculations (TD-DFT). The influences of different solvents on the absorption and One-Photon Excited Fluorescence (OPEF) spectral behavior, quantum yields and the lifetime of the chromophores have been investigated in detail. The third-order nonlinear optical (NLO) properties were investigated by open/closed aperture Z-scan measurements using femtosecond pulse laser in the range from 680 to 1080 nm. These results revealed that ZnLCl2 and ZnLBr2 exhibited strong two-photon absorption and ZnLCl2 showed superior optical power limiting property.

Synthesis, crystal structures and spectral properties of 6'-phenyl-2,2'-bipyridine derivatives and their CdLI(2) complexes.

Two novel 6'-phenyl-2,2'-bipyridine ligands (L1, L2) and their CdL(1,2)I2 complexes (1, 2) were synthesized and characterized by elemental analysis, (1)H NMR, IR, MALDI-TOF spectroscopy, and single crystal X-ray diffraction analysis. The results reveal that the central cadmium(II) atom in the complexes was coordinated by two iodide ions and two nitrogen atoms from L1, L2, forming a distorted coordination geometry. The electronic absorption properties of them were investigated on the basis of theoretical calculations (TD-DFT).