The asymmetric unit of the title compound, C10H8O3, contains two independent mol-ecules, both of which are almost planar (r.m.s deviations for all non-H atoms of 0.044 and 0.053 Å). The dihedral angles between the benzene ring and the prop-1-yne group are 3.47 (1) and 3.07 (1)° in the two mol-ecules, and the prop-1-yne groups adopt extended conformations. In each mol-ecule, an intra-molecular O...

In the title compound, 2C(5)H(8)N(3) (+)·C(4)H(4)O(6) (2-)·H(2)O, the two cations are essentially planar [maximum deviations = 0.023 (1) and 0.026 (1) Å]. In one of the cations, the protonated N atom and one of the amino group H atoms are hydrogen bonded to one of the carboxyl groups of the dianion through a pair of N-H⋯O hydrogen bonds, forming an R(2) (2)(8) ring motif. In the crystal structu...

The title compound, 3C(10)H(8)N(4)·2C(7)H(6)O(5)·2CH(4)O, has a mol-ecular crystal structure which results from the cocrystallization of gallic acid (GA), 4,4'-azodipyridine (AzPy) and methanol in a 2:3:2 molar ratio. The asymmetric unit comprises one molecule each of GA, AzPy and methanol in general positions and half a molecule of AzPy as this is located about a centre of inversion. In the cr...

In the title compound, {[La(C(6)H(4)NO(2))(2)(H(2)O)(4)]Cl}(n), the La(III) atom lies on a twofold rotation axis and is eight-coordinated by four O atoms from four isonicotinate ligands and four water mol-ecules in a distorted square-anti-prismatic coodination environment. Adjacent La(III) atoms are bridged by two carboxyl-ate groups from two isonicotinate ligands, forming an extended chain alo...

Let $R$ be a prime ring of characteristic not equal to $2$, $U$ the Utumi quotient and $C$ extended centroid $R$. $G$ $F$ two generalized derivations on $L$ non-central Lie ideal If $F\Big(G(u)\Big)u = G(u^{2})$ for all $u \in L$, then one following holds: (1) $G=0$. (2) There exist $p,q U$ such that $G(x)=p x$, $F(x)=qx$ $x R$ with $qp=p$. (3) satisfies $s_4$.

MOTIVATION Classification of biological samples by microarrays is a topic of much interest. A number of methods have been proposed and successfully applied to this problem. It has recently been shown that classification by nearest centroids provides an accurate predictor that may outperform much more complicated methods. The 'Prediction Analysis of Microarrays' (PAM) approach is one such exampl...

Article history: Received 30 October 2015 Received in revised form 3 March 2016 Accepted 8 March 2016 Available online 17 March 2016 In many scientific areas, researchers collect multivariate time profile data on the evolution of a set of variables across time for multiple persons. For instance, clinical studies often focus on the effects of an intervention on different symptoms for multiple pe...

In this paper we present a technique for shape similarity estimation and apply it to content-based indexing and retrieval over large image databases. This technique is based on wavelet decomposition and uses polygonal approximation. It uses simple features (aspect ratio, angles, distances from the centroid, distance ratios and relative positions) extracted at high curvature points. The experime...

Let R be a prime ring of characteristic different from 2, C the extended centroid of R, and δ a generalized derivations of R. If [[δ(x), x], δ(x)] = 0 for all x ∈ R then either R is commutative or δ(x) = ax for all x ∈ R and some a ∈ C. We also obtain some related result in case R is a Banach algebra and δ is either continuous or spectrally

Abstract Opposition-based learning (OBL) is often embedded in intelligent optimization algorithms to solve practical engineering and mathematical problems, but the combinatorial problems among different OBL variants are rarely studied. To this end, we propose a novel variant based on principle of optical imaging, which combines two types quasi-opposite extended opposite learning, called diversi...