String stability of infinite interconnected systems

ＩｎｔｒｏｄｕｃｔｉｏｎＩｎｔｈｅｉｎｄｕｓｔｒｉａｌｐｒａｃｔｉｃｅ ,ｍａｎｙｃｏｎｔｒｏｌｐｒｏｂｌｅｍｏｆｓｙｓｔｅｍｓｃａｎｂｅｓｔｕｄｉｅｄｔｈｒｏｕｇｈｉｎｔｅｒｃｏｎｎｅｃｔｅｄｓｙｓｔｅｍｓ.Ｅａｒｌｉｅｒｒｅｓｅａｒｃｈｏｎｉｎｔｅｒｃｏｎｎｅｃｔｅｄｓｙｓｔｅｍｆｏｃｕｓｅｄｏｎｐｏｗｅｒｓｙｓｔｅｍ[1,2 ],ｃｏｎｔｒｏｌｏｆｄｉｓｔｒｉｂｕｔｅｄｓｙｓｔｅｍｓ (ｅ .ｇ .,ｒｅｇｕｌａｔｉｏｎｏｆｓｅｉｓｍｉｃｃａｂｌｅｓ,ｖｉｂｒａｔｉｏｎｃｏｎｔｒｏｌｉｎｂｅａｍｓ,ｅｔｃ.) …     

Jordan tori for a torsion free abelian group

We classify Jordan G-tori, where G is any torsion-free abelian group. Using the Zelmanov prime structure theorem, such a class divides into three types, the Hermitian type, the Clifford type, and the Albert type. We concretely describe Jordan G-tori of each type.     

Athermal silica-based interferometer-type planar light-wave circuits realized by a multicore fabrication method

Athermal silica-based interferometer-type planar light-wave circuits were realized by a newly developed multicore fabrication method. In this method, inductively coupled chemical-vapor deposition and polishing technologies are adopted on a silica substrate with a trench-type waveguide pattern prepared by reactive ion etching. Two kinds of deposited core material, 10GeO2-90SiO2 (mol. %) and 8GeO2-5B2O3-87SiO2 (mol. %), which show wavelength temperature dependence of 9.7 and 8.1 pm/degree C, respectively, were used to prepare the waveguide sections in a device. By adjustment of the lengths of waveguide sections with these two different core materials, athermal characteristics of less than 0.5 pm/degree C were achieved for Mach-Zehnder interferometer filter devices at the 1.55-microm wavelength range while the temperature varied from -20 to 80 degrees C. The new method is also applicable for the preparation of many other kinds of functional devices.     

Structural Report for Sc[(R,R)-norephedrine-pybox](OTf)3 Dimeric Complex

Abstract The title compound containing two metal centers each complexes to one enantiopure chiral norephedrine-derived pyridyl-(bis) oxazoline (pybox) ligand and linked by two hydroxide bridges, crystallizes to give rodlike form in the space group P2₁(# 4). Cell Parameters are a = 10.2344(18) ?, b = 13.952(3) ?, c = 23.371(4) ?, β = 94.586(4)°, V = 3326.6(10) ?³. The metal-hydroxide motif forms a square plane at the center of the structure with the scandium centers exhibiting a distorted pentagonal bipyramid coordination sphere consisting of the chelating ligand and two additional triflouromethyl sulfonyloxy species positioned anti to each other. Graphical abstract The complex contains two metal centers each complexes to one enantiopure chiral norephedrine-derived pyridyl-(bis) oxazoline (pybox) ligand and linked by two hydroxide bridges. Structural report for Sc[(R,R)-norephedrine-pybox](OTf)₃ dimeric complex Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

N,N'-dipyridoxyl Schiff bases: synthesis, experimental and theoretical characterization

Three N,N'-dipyridoxyl Schiff bases (L1, L2 and L3) have been newly synthesized and characterized by IR, (1)H NMR, mass spectrometry and elemental analysis. Their optimized geometries together with the theoretical assignment of the vibrational frequencies and the (1)H NMR chemical shifts of them have been computed by using density functional theory (DFT) method. In the optimized structures of the Schiff bases, two pyridine rings are not in a same plane; however the substitutions are essentially in the same plane with the pyridine rings. Also, the benzene ring(s) in the bridge region is (are) not in the same plane with the pyridine rings and azomethine moieties. In all the species, engagement in intramolecular-hydrogen bonds causes to weakness of the phenolic O-H bonds. Consistency between the theoretical results and experimental evidence confirms suitability of the optimized geometries for the synthesized Schiff bases.     

One‐pot multicomponent synthesis of novel 2‐(piperazin‐1‐yl) quinoxaline and benzimidazole derivatives,using a novel sulfamic acid functionalized Fe3O4 MNPs as highly effective nanocatalyst

The immobilization of sulfonic acid on the surface of Fe₃O₄ magnetic nanoparticles (MNPs) as a novel acid nanocatalyst has been successfully reported. The morphological features, thermal stability, magnetic properties, and other physicochemical properties of the prepared superparamagnetic core–shell (Fe₃O₄@PFBA–Metformin@SO₃H) were thoroughly characterized using Fourier transform infrared (FTIR), X‐ray diffraction (XRD), energy‐dispersive X‐ray spectroscopy (EDS), field‐emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), thermogravimetric analysis–differential thermal analysis (TGA‐DTA), atomic force microscopy (AFM), dynamic light scattering (DLS), Brunauer–Emmett–Teller (BET), and vibrating sample magnetometer (VSM) techniques. It was applied as an efficient and reusable catalyst for the synthesis of 2‐(piperazin‐1‐yl) quinoxaline and benzimidazole derivatives via a one‐pot multiple‐component cascade reaction under green conditions. The results displayed the excellent catalytic activity of Fe₃O₄@PFBA–metformin@SO₃H as an organic–inorganic hybrid nanocatalyst in condensation and multicomponent Mannich‐type reactions. The easy separation, simple workup, excellent stability, and reusability of the nanocatalyst and quantitative yields of products and short reaction time are some outstanding advantages of this protocol.     

Design,synthesis, activity evaluation and QSAR studies of novel antimalarial 1,2,3-triazolo-β-lactam derivatives

This paper describes the synthesis of some new β-lactam derivatives containing the 1,2,3-triazole moiety. All the compounds were evaluated for their in vitro antimicrobial and antimalarial activities. Moderate to excellent antimalarial activities were encountered. The results showed that compounds 5a, 5c, 5f, 5i exhibited the most potent antimalarial activity with IC₅₀ values of 0.85, < 0.97, < 0.97, 1.81 µM against chloroquine-resistant P. falciparum K1 strain. A QSAR study highlights the structure–activity relationships that correlate the observed antimalarial activities with changes in the compounds’ structural features.