The novel well-defined chiral bicyclic thioureas based on enantiopure unsymmetric cis-2,5-disustituted pyrrolidine skeleton were firstly synthesized and fully characterized by their H NMR, C NMR and HRMS. Their absolute configurations were also determined by single-crystal X-ray analysis.

A new unsymmetric guest compound comprising ferrocene and azobenzene moieties was synthesized and can form a host-guest system with beta-cyclodextrin (beta-CD) complexed. The complexation stoichiometries and sites of the ensembles can be selectively controlled by reversible redox and photoirradiation.

The photodynamics in symmetric and unsymmetric β-diketones are studied with transient absorption in the deep-UV. Excitation leads to ultrafast ESIPT while further relaxation and isomerization processes depend on the molecular symmetry and solvent environment. OCIS codes: (320.7150) Ultrafast spectroscopy; (300.6540) Spectroscopy, ultraviolet; (190.7110) Ultrafast nonlinear optics

We present an overview of eigen analysis methods and their applications to network analysis. We consider several network analysis programs/procedures (Correspondence Analysis, NEGOPY, CONCOR, CONVAR, Bonacich centrality) that are at their core eigendecomposition methods. We discuss the various matrix representations of networks used by these procedures and we give particular attention to a vari...

Eigen decomposition is a central mathematical tool in many pattern recognition and machine learning techniques. However, it becomes computationally infeasible in the presence of a large set of high-dimensional samples. Moreover, in highly dynamic domains with a continual supply of new samples, an incremental approach that keeps on updating the eigen decomposition will be more desirable than the...

For a sparse symmetric matrix, there has been much attention given to algorithms for reducing the bandwidth. As far as we can see, little has been done for the unsymmetric matrix A, which has distinct lower and upper bandwidths l and u. When Gaussian elmination with row interchanges is applied, the lower bandwidth is unaltered while the upper bandwidth becomes l+u. With column interchanges, the...