Approximate solution for kinetic differential equations

Summary In the present work we show the analysis of an approximate solution for the coupled kinetic differential equations of a defect involving processes of untrapping, retrapping and recombination annihilation, using the Poincaré-Dulac theorem. The authors of this paper have agreed to not receive the proofs for correction.     

Decentralized robust control for a class of uncertain large-scale interconnected nonlinear dynamical systems

The problem of the decentralized robust control for a class of large-scale interconnected nonlinear dynamical systems with input interconnection and external interconnection perturbations is considered. Based on the stabilizability of each nominal isolated subsystem (i.e., the isolated subsystem in the absence of interconnection perturbations), a class of decentralized local state feedback controllers is proposed, and some sufficient conditions are derived by making use of the Lyapunov stability criterion such that uncertain large-scale interconnected systems can be stabilized asymptotically by these decentralized state feedback controllers. For large-scale systems with only input interconnection perturbations, such decentralized controllers become a class of decentralized stabilizing state feedback controllers. That is, the decentralized stability of such large-scale systems can be guaranteed always by using the decentralized state feedback controllers proposed in the paper. Finally, a numerical example is given to demonstrate the validity of the results.     

Synthesis of polyamideamines from 5-oxazolones

Polyamideamines with a sequence of two amide and one amine linkage in a main chain were synthesized from the polyaddition of 2-isopropylidene-4-alkyl-3-oxazolin-5-ones and primary diamines. The polyaddition reaction proceeded through 1,4-conjugate addition of an amine group to 3-oxazolin-5-one and subsequent ring opening of the intermediate addition product with another amine. Although aliphatic diamines gave oily polymers, xylylenediamines afforded amorphous solid polymers. The reduced viscosities and polymer melt temperature of the polymers were 0.05–0.12 and 90–130°C., respectively.     

New sesquiterpene lactones from water extract of the root of Lindera strychnifolia with cytotoxicity against the human small cell lung cancer cell, SBC-3

In the present study, new sesquiterpene lactones (1) and (2) were isolated from the EtOAc soluble fraction of the water extract of Linderae Radix through bioassay-guided fractionation and isolation methods. The structure of these compounds was elucidated by spectroscopic analysis of their 2D NMR spectra, including COSY, HMBC, and HMQC techniques. Two isolates showed significant cytotoxicity against the human small cell lung cancer cell SBC-3, and lesser cytotoxicity against mouse fibroblast cell 3T3-L1.     

Dielectric properties of poly [3,3-bis(chloromethyl)oxacyclobutane] (Penton)

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Structure-reactivity correlations in nucleophilic substitution reactions of Y-substituted phenyl X-substituted benzoates with anionic and neutral nucleophiles

A kinetic study is reported for the reactions of 4-nitrophenyl X-substituted benzoates (1a-1) and Y-substituted phenyl benzoates (2a-1) with two anionic nucleophiles (OH(-) and CN(-)) and three amines (piperidine, hydrazine, and glycylglycine) in 80 mol% H(2)O-20 mol% dimethyl sulfoxide (DMSO) at 25.0 +/- 0.1 degrees C. Each Hammett plot exhibits two intersecting straight lines for the reactions of 1a-1 with the anionic nucleophiles and piperidine, while the Yukawa-Tsuno plots for the same reactions are linear. The Hammett plots for the reactions of 2a-1 with hydrazine and glycylglycine demonstrate much better linear correlations with sigma(-) constants than with sigma degrees or sigma constants, indicating that the leaving group departure occurs at the rate determining step (RDS). On the contrary, sigma(-) constants result in poorer Hammett correlation than sigma degrees constants for the corresponding reactions with OH(-) and CN(-), indicating that the leaving group departure occurs after the RDS for the reactions with the anionic nucleophiles. The large rho(X) value (1.7 +/- 0.1) obtained for the reactions of 1a-1 with the anionic nucleophiles supports the proposal that the reactions proceed through an addition intermediate with its formation being the RDS.     

STM imaging of a model surface of Ru(4,4′-dicarboxy-2,2′-bipyridine)2(NCS)2 dye-sensitized TiO2 photoelectrodes

A TiO₂(1 1 0)-(1 × 1) surface was prepared in an ultra-high vacuum, transported in laboratory air, and observed with a scanning tunneling microscope (STM) operated in a vacuum of 10⁻⁴ Pa. Empty state images showed atomically flat terraces separated by single-height steps, on which 5-fold-coordinated surface Ti atoms were observed as spots arranged in a rectangular lattice. The Ru(4,4′-dicarboxy-2,2′-bipyridine)₂(NCS)₂ (N3) dye was adsorbed on the TiO₂ surface by immersing the TiO₂ wafer into an acetonitrile solution of the dye. In the empty state images, individual N3 molecules were observed as oval particles protruding by 0.6 nm from the TiO₂ surface. The oval shape elongated to the [1  0] directions was attributed to electron tunneling from tip to unoccupied states localized at the two carboxyl groups bound to the TiO₂ surface.     

Effect of Alkynyl Group on Reactivity in Photoaffinity Labeling with 2-Thienyl-Substituted α-Ketoamide

Minimalist photo-reactive probes, which consist of a photo-reactive group and a tag for detection of target proteins, are useful tools in chemical biology. Although several diazirine-based and aryl azide-based minimalist probes are available, no keto-based minimalist probe has yet been reported. Here we describe minimalist probes based on a 2-thienyl-substituted α-ketoamide bearing an alkyne group on the thiophene ring. The 3-alkyne probe showed the highest photo-affinity labeling efficiency.