Some remarks on global existence to the Cauchy problem of the wave equation with nonlinear dissipation

In this paper we prove the existence of global decaying H² solutions to the Cauchy problem for a wave equation with a nonlinear dissipative term by constructing a stable set in H¹(?ⁿ ). (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Synthesis of polystyrene–poly(tert‐butyl methacrylate)–poly(ethylene oxide) triarm star block copolymers

Three alternative routes, using the heterobifunctional macroinitiator technique, have been developed to obtain polystyrene–poly(tert‐butyl methacrylate)–poly(ethylene oxide) triarm star block copolymers. Only the route showing the reverse initiation of tert‐butyl methacrylate on potassium alkoxide leads to the pure star, whereas the other strategies lead to incomplete initiation because of either an increase in the side reactions, such as transesterification, or a decrease in the accessibility toward bulky catalysts. These limits are linked to the particular location of the initiating group at the junction of the two blocks of the copolymer precursor. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 1745–1751, 2004     

Reactivity of N‐benzyl‐3‐nitrophthalimide: A facile access to isoindolo[1,2‐d][3,5]benzothiazocine derivatives

A functionalized isoindolo[1,2‐d][3,5]benzothiazocine 2B has been synthesized in three steps from the nitro‐imide derivative 5. The key step of this sequence was the cyclization of the thioglycolic acid derivative 9 under acidic conditions. An evaluation of the reactivity of the imide 5 and the corresponding N‐acyliminium ion toward borohydride reduction, organometallic addition, Meyer‐Schuster rearrangement and intermolecular alkoxylation and thioalkoxylation reactions was reported.     

The Euler–Bernoulli beam equation with boundary dissipation of fractional derivative type

We consider a Euler–Bernoulli beam equation with a boundary control condition of fractional derivative type. We study stability of the system using the semigroup theory of linear operators and a result obtained by Borichev and Tomilov. Copyright © 2016 John Wiley & Sons, Ltd.     

On neutrino masses and source of dark energy

We propose a Higgs-extended model in which neutrinos naturally acquire tiny Majorana masses as constrained by the electroweak precision data, while the associated pseudo Nambu–Goldstone boson serves as an attractive candidate for dark enegy.     

Exact Null Controllability of a Stage and Age-Structured Population Dynamics System

This paper is concerned with the exact null controllability of an age-dependent life cycle dynamics with nonlocal transition processes arising as boundary conditions. We investigate the controllability for the pest by acting on eggs in a small age interval. The main method is based on the derivation of estimations for the adjoint variables related to an optimal control problem. A fixed point theorem is then used to draw conclusions.     

Fragmentation Study of Globularin Through Positive and Negative ESI/MS,CID/MS,and Tandem MS/MS

Abstract

The structure of globularin was studied by a mass spectrometric methodology based on the combined use of positive and negative electrospray ionization, collision‐induced dissociation (CID), and tandem mass spectrometry. The mass spectrometry investigation was achieved through in‐source fragmentation of the deprotonated [M?H]^?, protonated [M+H]⁺, lithiated [M+Li]⁺, sodiated [M+Na]⁺, and potassium‐cationized [M+K]⁺ ions. This allowed collision‐induced dissociation spectra of the ionized molecular ions to be obtained to give valuable structural information regarding the nature of both the glycoside and the aglycone moieties and the effect of metal cationization on the CID spectra. Glycosidic fission and ring cleavages of both aglycone and sugar moieties were the major fragmentation pathways observed during collision‐induced dissociation, where the losses of small molecules, the cinnamoyl and the cinnamate parts were also observed. Alkali metal cationization offers additional fragmentation pathways involving cross rings cleavage under CID conditions. Unlike the dissociation of protonated molecular ions, that of metal‐cationized molecules also provides sugar fragments where the C₀ ⁺ fragment corresponding with the glucose ion was obtained as a major daughter peak for all the studied compounds. Even with low abundance, fragment ions coordinated to K⁺ were also observed from [M+K]⁺.