Search results for "Trigo"
showing 10 items of 253 documents
Synthesis of and structural studies on lead(II) cysteamin complexes.
2004
The novel compounds PbCl(2).(SCH(2)CH(2)NH(3)) (1), Pb(SCH(2)CH(2)NH(2))(2).2PbCl(SCH(2)CH(2)NH(2)) (2), and Pb(SCH(2)CH(2)NH(2))(2) (3) were synthesized by reaction of PbO or PbCl(2) with [HSCH(2)CH(2)NH(3)]Cl and NaOH, and were characterized by elemental analysis, IR-, and UV/vis-spectroscopy. Single-crystal X-ray diffraction revealed different coordination modes for the two Pb atoms in 2. The Pb atom in the Pb(SCH(2)CH(2)NH(2))(2) unit forms two covalent Pb-S and two intramolecular dative Pb...N bonds, leading to a pseudo trigonal bipyramidal configuration with a stereochemically active lone pair. The Pb atom in the PbCl(SCH(2)CH(2)NH(2)) unit, the first moiety structurally characterized…
Millimeter-Scale and Billion-Atom Reactive Force Field Simulation on Sunway Taihulight
2020
Large-scale molecular dynamics (MD) simulations on supercomputers play an increasingly important role in many research areas. With the capability of simulating charge equilibration (QEq), bonds and so on, Reactive force field (ReaxFF) enables the precise simulation of chemical reactions. Compared to the first principle molecular dynamics (FPMD), ReaxFF has far lower requirements on computational resources so that it can achieve higher efficiencies for large-scale simulations. In this article, we present our efforts on scaling ReaxFF on the Sunway TaihuLight Supercomputer (TaihuLight). We have carefully redesigned the force analysis and neighbor list building steps. By applying fine-grained …
Response Power Spectrum of Multi-Degree-of-Freedom Nonlinear Systems by a Galerkin Technique
2003
This paper deals with the estimation of spectral properties of randomly excited multi-degree-of-freedom (MDOF) nonlinear vibrating systems. Each component of the vector of the stationary system response is expanded into a trigonometric Fourier series over an adequately long interval T. The unknown Fourier coefficients of individual samples of the response process are treated by harmonic balance, which leads to a set of nonlinear equations that are solved by Newton’s method. For polynomial nonlinearities of cubic order, exact solutions are developed to compute the Fourier coefficients of the nonlinear terms, including those involved in the Jacobian matrix associated with the implementation o…
Synthesis, characterization, and in vitro antimicrobial activity of organotin(IV) complexes with triazolo-pyrimidine ligands containing exocyclic oxy…
2005
Abstract Tri-organotin(IV) complexes of the triazolo-pyrimidine derivatives 4,5-dihydro-5-oxo-[1,2,4]triazolo-[1,5 a ]pyrimidine (5HtpO), 4,7-dihydro-5-methyl-7-oxo-[1,2,4]triazolo-[1,5 a ]pyrimidine (HmtpO), and 4,5,6,7-tetrahydro-5,7-dioxo-[1,2,4]triazolo-[1,5 a ]pyrimidine (H 2 tpO 2 ), and the diorganotin derivative n -Bu 2 Sn(tpO 2 ), were synthesized and characterized by means of infrared and 119 Sn Mossbauer spectroscopy. In all the complexes obtained the triazolopyrimidines act as multidentate ligands producing polymeric structures. A trigonal bipyramidal arrangement of the ligands around the tin atom is proposed for triorganotin(IV) derivatives, with organic groups on the equatoria…
Structural investigations on diorgano- and triorganotin(IV) derivatives of [meso-tetra(4-sulfonatophenyl)porphine]metal chlorides.
2006
Abstract Several new complexes of organotin(IV) moieties with MCln[meso-tetra(4-sulfonatophenyl)porphine], (R2Sn)2MCln[meso-tetra(4-sulfonatophenyl)-porphinate]s and (R3Sn)4MCln [meso-tetra(4-sulfonatophenyl)porphinate]s, [M = Fe(III), Mn(III): n = 1, R = Me, n-Bu; Ph; M = Sn(IV): n = 2, R = Me, n-Bu] have been synthesized and their solid state configuration investigated by infrared (IR) and Mossbauer spectroscopy, and by 1H and 13C NMR in D2O. The electron density on the metal ion coordinated inside the porphyrin ring is not influenced by the organotin(IV) moieties bonded to the oxygen atoms of the side chain sulfonatophenyl groups, as it has been inferred on the basis of Mossbauer spectro…
Indefinite integrals of some special functions from a new method
2015
A substantial number of indefinite integrals of special functions are presented, which have been obtained using a new method presented in a companion paper [Conway JT. A Lagrangian method for deriving new indefinite integrals of special functions. Integral Transforms Spec Funct. 2015; submitted to]. The method was originally derived from the Euler–Lagrange equations but an elementary proof is also presented in [Conway JT. A Lagrangian method for deriving new indefinite integrals of special functions. Integral Transforms Spec Funct. 2015; submitted to]. Sample results are presented here for Bessel functions, Airy functions and hypergeometric functions. More extensive results are given for th…
Pseudo-Abelian integrals along Darboux cycles
2008
We study polynomial perturbations of integrable, non-Hamiltonian system with first integral of Darboux-type with positive exponents. We assume that the unperturbed system admits a period annulus. The linear part of the Poincare return map is given by pseudo-Abelian integrals. In this paper we investigate analytic properties of these integrals. We prove that iterated variations of these integrals vanish identically. Using this relation we prove that the number of zeros of these integrals is locally uniformly bounded under generic hypothesis. This is a generic analog of the Varchenko-Khovanskii theorem for pseudo-Abelian integrals. Finally, under some arithmetic properties of exponents, the p…
Interlocking inorganic screw helices: synthesis, structure, and magnetism of the novel framework uranium orthothiophoshates A11U7(PS4)13 (A = K, Rb).
2002
The novel quaternary uranium thiophosphate K11U7(PS4)13 has been synthesized by reacting uranium metal, K2S, S, and P2S5 at 700 degrees C in an evacuated silica tube. The crystal structure was determined by single crystal X-ray diffraction techniques. K11U7(PS4)13 crystallizes in the tetragonal space group I42d (a = 32.048(2) A, c = 17.321(1) A, Z = 8). The structure contains a tunnel framework composed of eight interlocking uranium U7(PS4)13 screw helices, with alkali metal cations residing inside the framework channels. The uranium atoms are coordinated in a bi- or tricapped trigonal prismatic fashion. The screw helices are built up from uranium atoms interconnected by PS4 tetrahedral uni…
Braquiópodos devónicos de la Cordillera Cantábrica (Norte de España). 12) Ferronirhynchia nuevo género de rinconélido (Trigonirhynchiidae) del Emsien…
2021
The taxonomic status of the subfamily Trigonirhynchiinae is discussed based on the morphological features, together with the geographic and the stratigraphic distribution of the type genus Trigonirhynchia Cooper. The new genus, Ferronirhynchia n. gen., including the type species F. pulgari n. sp., is proposed. The new taxon, close to Trigonirhynchia , occurs in upper Emsian beds of the Moniello Formation, in Asturias, serotinus/patulus conodont zones, Faunal Intervals 14 to 16a. The ontogeny and palaeoecology of F. pulgari are analyzed. Growth of the new species is bicyclic. Juvenile forms are low and biconvex displaying sharp commissures. Adult forms are high, dorsi-biconvex, ge…
Angiotensin II, type 2 receptor in the development of vesico-ureteric reflux
2001
Objective To investigate if mutation of the angiotensin II (Ang II) receptors AT2 is involved in primary vesico-ureteric reflux (VUR) in humans. Patients and methods Genetic polymorphisms in the AT1 and AT2 receptors was evaluated in 23 patients having the most common congenital urological abnormality, namely primary congenital VUR. The occurrence of the A1166C transition in the AT1 receptor gene and the A-1332G transition in the AT2 receptor gene were evaluated and compared with the incidence in normal controls with no urological abnormalities. Result The distribution of the AT1 receptor genotypes was no different between patients with VUR and healthy controls. Furthermore, 10 of 23 (44%) …