Synthesis, Structure, and Optical Limiting Properties of an Axial Substituted Bis(8-oxide quinoline)zirconium Phthalocyanine

A novel bis(8-oxide quinoline)zironium phthalocyanine [(OQ)2 Zr Pc] with two 8-oxide quinolone anions at the same axial positions has been successfully synthesized and its chemical structure has been assigned by the 1 H NMR, MS and two-dimensional correlation infrared(2D-IR) spectroscopy as well as by single-crystal X-ray structural analysis. It possessed a moderately effective nonlinear absorption coefficient βeff of 6.69×10-14cm/GW at 532 nm in DMF solution, implying it is a promising candidate for nonlinear optical materials.

Two-Photon Absorption and Excited State Dynamics of Two Organic Molecules Containing Donor/Acceptor Moieties

Two new two-photon absorption （TPA） molecules, named SK-G1 and NT-G1, are synthesized and the photo- physical characteristics are investigated by using linear absorption spectra, one-photon fluorescence spectra and two-photon excited fluorescence spectra. Both the compounds exhibit TPA properties, and the TPA values determined by z-scan measurement are 10 GM and 39 GM for SK-G1 and NT-G1, respectively, at wavelength 80Ohm. Time-resolved spectroscopic techniques are employed to further explore the excited state dynamics of NT-G l with larger TPA cross section. The research results show that there is an ultrafast intraband energy transfer process （about 3ps） before the formation of charge transfer state with a relatively long lifetime.

Optical Performance and Nonlinear Scattering of Soluble Polystyrene Grafted Multi-Walled Carbon Nanotubes

Three soluble polystyrene grafted multi-walled carbon nanotube （MWNT） samples are synthesized, and their optical performance and nonlinear scattering properties are investigated by z-scan method using nanosecond pulses of 532 nm from a frequency-doubled Q-switched Nd： YLF laser. Analysis of the experimental results shows that other than nonlinear scattering, nonlinear absorption plays a major role in optical limiting performance of these stable and well-dispersed suspensions. These new synthesized materials which can be better dispersed in common organic solvents than MWNT itself can be considered as potential sources for further optical applications.

The limit properties of spatial coherence of seismic ground motion

The limit properties of spatial coherence of seismic ground motion are studied based on the differential relation between rotation and translation in elastic theory, the results show that the empirical mathematical model of spatial coherence must satisfy some functional characteristics. It is also indicated that the key problem to estimate rotational power spectrum densities is to obtain precisely the two order derivative of spatial coherence.

Synthesis,Structure and Optical Limiting (OL) Properties of a Novel Incomplete Cubane-like Cluster [PPh_4][(η~5-C_5Me_5) WS_3-(CuBr)(CuI)_2(μ-dppm)]

Reaction of [PPh_4][(η 5-C_5Me_5)WS_3] with CuI,CuBr and bis^(diphenylphosphino)methane (dppm) (molar ratio=1∶2∶1∶1) in MeCN gave rise to [PPh_4][(η 5-C_5Me_5)WS_3(CuBr)(CuI)_2-(μ-dppm)] (1) in high yield. Compound 1 crystallizes in the monoclinic,space group P2_1/n with lattice parameters:a=1.2906(4) nm, b=1.5006(8) nm,c=3.1484(6) nm,β= 92.12(2)°,V=6.093(3) nm 3,Z=4. The structure of the anion of 1 contains an incomplete WS_3Cu_3 cubane-like core in which two CuI units are bridged by a dppm ligand. The W—Cu distances vary in the range of 0.2644(1)—0.2793(1) nm. The optical limiting (OL) properties of 1 in MeCN were measured with the laser pulse-width of 12-ns at 532 nm,and the nanosecond OL effect may be due to the reverse saturable absorption (RSA) related to the excited triplet states.

Nonlinear optical and optical limiting properties of new structures of organic nonlinear optical materials for photonic applications

The nonlinear optical （NLO） and optical limiting （OL） properties of three new structures of organic NLO guest host Poly（N-vinylcarbozole）/disperse orange 3 （PVK/DO3）, PVK/disperse orange 13 （PVK/DO13）. and PVK/disperse orange 25 （PVK/DO25） as a solution at different concentrations and as a thin-film sample are studied using continuous wave z-scan system at 532 nm. The open-aperture z-scan data of the NLO materials in the solution and thin-film samples displayed two-photon and saturable absorptions, respectively. The PVK/DO13 exhibites the largest and best values of the nonlinearities, such as n2, β, X（3） compared with those of PVK/DO3 and PVK/DO25. This nonlinearity increases as the concentration increases. Tile results indicate that these NLO materials are good candidates for optical switching and OL devices.

Nonzero Solubility Rule

A solubility related rule, nonzero solubility rule, is introduced in this paper. It is complementary to the existing rules such as the “like dissolves like” rule and can be understood on the basis of classical chemical thermodynamics.

Normal Systems over ANR's, Rigid Embeddings and Nonseparable Absorbing Sets

Most of results of Bestvina and Mogilski [Characterizing certain incomplete infinite-di- mensional absolute retracts. Michigan Math. J., 33, 291-313 （1986）] on strong Z-sets in ANR＇s and absorbing sets is generalized to nonseparable case. It is shown that if an ANR X is locally homotopy dense embeddable in infinite-dimensional Hilbert manifolds and w（U） ---- w（X） （where ＂w＂is the topological weight） for each open nonempty subset U of X, then X itself i,~ homotopy dense embeddable in a Hilbert manifold. It is also demonstrated that whenever X is an AR, its weak product W（X, ＊） ---- {（xn）=l C X ： x~ = ＊ for almost all n} is homeomorphic to a pre-Hilbert space E with E EE. An intrinsic characterization of manifolds modelled on such pre-Hilbert spaces is given.