Bis{2-eth­oxy-6-[2-(ethyl­ammonio)ethyl­imino­meth­yl]phenolato}thio­cyanato­zinc(II) nitrate

The title complex, [Zn(NCS)(C13H20N2O2)2]NO3, consists of a complex mononuclear ZnII cation and a nitrate counter-anion. The ZnII ion is five-coordinate in a trigonal-bipyramidal geometry. The thio­cyanate N atom and two O atoms from two Schiff bases define the equatorial plane, and the two imine N atoms from the same two Schiff bases occupy the axial positions, with an N—Zn—N angle of 175.98 (7)°. The amine N atoms of the Schiff base ligands are protonated and are not involved in the coordination to the metal. The dihedral angle between the two substituted benzene rings is 87.7 (2)°. The nitrate counter-ions are linked to the cations through N—H⋯O hydrogen bonds

A CASE STUDY OF A CHILD WITH ATTENTION DEFICIT/HYPERACIVITY DISORDER (ADHD) AND MATHEMATICS LEARNING DIFFICULTY (MLD)

This is a case study of a male child, EE, aged 8+ years, who was described as rather disruptive in class during lesson. For past years, his parents, preschool and primary school teachers noted his challenging behavior and also complained that the child showed a strong dislike for mathematics and Chinese language – both are examinable academic subjects. As a result of the disturbing condition, EE was referred to an educational therapist at a private intervention center for a diagnostic assessment. The child was identified with Attention Deficit-Hyperactivity Disorder (ADHD)-Combined subtype. This aim of this paper is to discuss about the effects of ADHD on mathematics learning and how to avoid misdiagnosis or over-diagnosis of a behavioral-cum-learning disorder.  Article visualizations

Modulation Instability, Breathers, and Bound Solitons in an Erbium-Doped Fiber System with Higher-Order Effects

We mainly investigate the generalized nonlinear Schrödinger-Maxwell-Bloch system which governs the propagation of optical solitons in nonlinear erbium-doped fibers with higher-order effects. We deduce Lax pair, analyze modulation instability conditions, construct the Darboux transformation, and derive the Akhmediev breathers, Ma-breathers, bound solitons, and two-breather solutions for this system. Considering the influences of higher-order effects, propagation properties of those solitons are discussed

Axion-meson mixing in light of recent lattice η\eta-η′\eta' simulations and their two-photon couplings within U(3)U(3) chiral theory

We study the mixing of the QCD/QCD-like axion and light-flavor mesons $\pi^0, \eta, \eta'$ within the framework of $U(3)$ chiral perturbation theory up to next-to-leading order in this work. The axion-meson mixing formulas are calculated order by order in the $U(3)$ $\delta$-expansion scheme, namely the joint expansions of the momentum, light-quark masses and $1/N_C$. We provide axion-meson mixing relations in terms of the $\pi^0$-$\eta$-$\eta'$ mixing parameters and their masses. The recent lattice simulations on the $\eta$-$\eta'$ systems turn out to be able to offer valuable inputs to constrain the unknown low-energy constants. The relation of the mass and decay constant of the axion is then further explored based on our updated calculations. The two-photon couplings of the light-flavor mesons, together with the axion, are also investigated in the $U(3)$ chiral theory up to next-to-leading order in the $\delta$-counting scheme.Comment: 23 pages, 3 figure