Regioregular poly(3-hexylthiophene)s with chain lengths varying from 5 to 100 monomers are synthesized. Poly(3-hexylthiophene)s show in solution an unexpectedly significant second-order nonlinear optical response. The increase in transition dipole moment upon oligomerisation causes the significant second-order nonlinear optical response.

We have observed electromagnetically induced transparency in a Doppler broadened molecular cascade system using fluorescence detection. We demonstrate that the power-dependent splitting of lines in the upper-level fluorescence excitation spectrum can be used as a new spectroscopic tool for the measurement of molecular transition dipole moment functions.

the question of whether architectural creativity is more of an artistic or engineering nature is one with a long history but also one with no conclusive answer. the art camp would argue that technology should be treated as a means towards and end, and that technology alone cannot give meaning to our lives. the engineering camp on the other hand would argue that good problem-solving results in b...

The photoswitching behavior of the polyacrylic acid (PAA) doped by methyl orange (MO) brush film was investigated using spectral analysis UV-Vis absorbance, Fourier Transformation Infrared spectroscopy, 2D electrical conductivity mapping and Atomic Force Microscopy. kinetics time evolution photoisomerization PAA-MO PEBs from E-state to Z-state UV-light irradiation, reverse thermal relaxation ex...

The one-photon absorption (OPA) properties of donor-pi-bridge-acceptor-pi-bridge-donor (D-pi-A-pi-D)-type 2,1,3-benzothiadiazoles (BTD) were studied with two dimensional (2D) site and three dimensional (3D) cube representations. The 2D site representation reveals the electron-hole coherence on electronic state transitions from the ground state. The 3D representation shows the orientation of tra...

Spatially embedded complex networks, such as nervous systems, the Internet, and transportation networks, generally have nontrivial topological patterns of connections combined with nearly minimal wiring costs. However, the growth rules shaping these economical tradeoffs between cost and topology are not well understood. Here, we study the cellular nervous system of the nematode worm Caenorhabdi...

We study sums of directed paths on a hierarchical lattice where each bond has either a positive or negative sign with a probability p. Such path sums J have been used to model interference effects by hopping electrons in the strongly localized regime. The advantage of hierarchical lattices is that they include path crossings, ignored by mean field approaches, while still permitting analytical t...

3-Hydroxyflavone (3HF) is a molecule that undergoes excited-state intramolecular proton transfer (ESIPT). Using electroabsorption we have detected the small changes in dipole moment (|∆μ b|) and polarizability (∆R) resulting from photon absorption for 3HF embedded in a noninteracting polyethylene environment. The values of |∆μ b| and ∆R obtained are also in good agreement with the results of ab...

The master probability equation captures the dynamic behavior of a variety of stochastic phenomena that can be modeled as Markov processes. Analytical solutions to the master equation are hard to come by though because they require the enumeration of all possible states and the determination of the transition probabilities between any two states. These two tasks quickly become intractable for a...

Zipf’s law predicts a power-law relationship between word rank and frequency in language communication systems, and is widely reported in texts yet remains enigmatic as to its origins. Computer simulations have shown that language communication systems emerge at an abrupt phase transition in the fidelity of mappings between symbols and objects. Since the phase transition approximates the Heavis...