Porous materials show superhydrophobic to superhydrophilic switching

Switching between superhydrophobicity and superhydrophilicity in porous materials was predicted theoretically and demonstrated experimentally with the example of thermally induced contact angle change; tunability of this system was also demonstrated.     

Photochemical reactions of substituted cyclobutadieneiron tricarbonyl complexes with acetylenes

When mixtures of monosubstituted cyclobutadieneiron tricarbonyl complexes and propyne are irradiated, substituted toluenes are obtained. The composition of the isomeric mixture is influenced by the nature of the substituent in the metal complex. Electron-withdrawing groups produce mixtures containing a very large percent of the ortho isomer while electron-releasing groups yield mixtures rich in the para isomer. Complex mixtures of isomeric benzene compounds are obtained when substituted acetylenes are allowed to react with methyl- or isopropylcyclobutadieneiron tricarbonyl.     

Double-antibody homogeneous fluorescence immunoassay of phenytoin

A homogeneous fluorescence immunoassay suitable for quantifying 5–25 mg l^?1 phenytoin (5,5-diphenyl-2,4-imidazolidenedione) in serum is described. The fluorophor-labeled phenytoin and unlabeled phenytoin (analyte) compete for a limited number of anti-phenytoin antibody binding sites in the presence of anti-fluorophor antibodies. The label employed is a sulfonamido derivative of 2-naphthol-8-sulfonic acid (2-8) which, at neutral pH, undergoes excited-state proton transfer. Binding of anti 2-8 antibodies to the drug-fluorophor conjugate results in quenching of the conjugate base emission at 480 nm. The relative standard deviations are about 5%.     

A photonic approach for microwave/millimeter-wave frequency measurement using stimulated brillouin scattering in single mode fiber

A photonic approach for microwave/millimeter-wave (MMW) frequency measurement is proposed and demonstrated based on stimulated Brillouin scattering (SBS) of a 20-km standard single mode fiber (SSMF). After the MMW signal is modulated to a laser source with two sidebands using optical carrier suppression (OCS) modulation, its frequency can be easily measured by monitoring the SBS-induced amplification with a power meter. Due to the 1-pm resolution of a tunable pump laser source, a frequency measurement range of 1–40 GHz is demonstrated in our experiment with a frequency resolution of 125 MHz. We believe the frequency measurement range can be further extended to satisfy photonic radar front-end processing application.     

Isoscattering deformations for complete manifolds of negative curvature

We construct continuous families of nonisometric metrics on simply connected manifolds of dimension n ≥ 9which have the same scattering phase, the same resolvent resonances, and strictly negative sectional curvatures. This situation contrasts sharply with the case of compact manifolds of negative curvature, where Guillemin/Kazhdan, Min-Oo, and Croke/Sharafutdinov showed that there are no nontrivial isospectral deformations of such metrics.     

A new stepwise synthesis of a family of propylamines derived from diatom silaffins and their activity in silicification

A new method for the stepwise synthesis of propylamines containing fragments of N-methyl propylamine as found in diatom bioextracts is presented and their activity in silicic acid condensation is described.