PROPERTY （X^＋） FOR SECOND-ORDER NONLINEAR DIFFERENTIAL EQUATIONS OF GENERALIZED EULER TYPE

In this paper the generalized nonlinear Euler differential equation t2k(tu′)u′′+t(f (u)+k(tu′))u′+g(u) = 0 is considered. Here the functions f (u), g(u) and k(u) sat-isfy smoothness conditions which gu...     

以蛋壳为原料制备的纳米氧化钙用于高效催化合成吡喃并[4,3-b]吡喃(英文)

Nano-CaO was prepared by calcination of ball-milled chicken eggshell waste.This novel,bioactive,heterogeneous catalyst,which had high catalytic activity and reusability,was used in the green synthesis of pyrano[4,3-b]pyrans via condensation of various aromatic aldehydes,malononitrile,and 4-hydroxy-6-methyl-2H-pyran-2-one at 120 °C under solvent-free conditions.The reaction proceeded to completion within 5–45 min in 93%–98% yield.The nano-CaO was fully characterized by scanning electron microscopy,X-ray powder diffraction,infrared spectroscopy,X-ray fluorescence spectroscopy,and thermal gravimetric,surface area,and elemental analyses.     

Optimal economic load dispatch based on wind energy and risk constrains through an intelligent algorithm

This article focus on optimal economic load dispatch based on an intelligent method of shark smell optimization (SSO). In this problem, the risk constrains has been considered which has root in uncertainity and unpredictable behavior of wind power. Regarding to increasing of this clean energy in power systems and un‐dispatchable behavior of wind power, its conditional value at risk index considered in this article which consists of loss from load and "spilling" wind energy connected with unpredictable imbalances among generation and load. This problem has been considered as an optimization problem based on SSO that evaluate the balance between cost and risk. This algorithm is based on distinct shark smell abilities for localizing the prey. In sharks' movement, the concentration of the odor is an important factor to guide the shark to the prey. In other words, the shark moves in the way with higher odor concentration. This characteristic is used in the proposed SSO algorithm to find the solution of an optimization problem. Effectiveness of the proposed method has been applied over 30‐bus power system in comparison with other techniques. © 2016 Wiley Periodicals, Inc. Complexity 21: 494–506, 2016     

Chromium(III) and Calcium(II) complexes obtained from dipicolinic acid: Synthesis, characterization, X-Ray crystal structure and solution studies

The Cr(III) and Ca(II) complexes (dmpH)[Cr(pydc)₂]?H₂O (1) and [Ca₂(pydc)₂(H₂O)₆].2pydcH₂ (2) were synthesized by reaction of 2,9-dimethyl-1,10-phenanthroline (dmp) and pyridine-2,6-dicarboxylic acid (pydcH₂) with Cr(NO₃)₃ and Ca(NO₃)₂, respectively, and characterized using IR spectroscopy, single crystal X-ray diffraction method and solution studies. The space group and crystal system of these two compounds are P2 ₁/c and monoclinic. The crystal dimensions are a = 9.785(3) Å, b = 25.671(4) Å, c = 9.3402(16) Å, β = 90.790(17)° for (1) and a = 9.1319(4) Å, b = 14.8430(8) Å, c = 12.2449(7) Å, β = 98.227(5)° for (2). In complex (1), a water molecule presents in the crystal packing, linking the anionic and cationic fragments together by hydrogen bonding and thus increases the stabilization of crystal lattices. In complex (2), the coordinated water molecules relate each dimer to adjacent dimers forming infinite molecular ribbons by strong hydrogen bondings. Hydrogen bonding and ion pairing play an important role in stabilizing these crystals. The complexation reactions of pydc, dmp and pydc+dmp with Cr³⁺ and Ca²⁺ ions in aqueous solution were investigated by potentiometric pH titrations and the equilibrium constants for all major complexes formed were evaluated.     

DFT Study of Endohedral Atoms Effect on Electrophilicity of B16N16 Boron Nitride Nanocage: Comparative Analyses

Endohedral derivatives of B₁₆N₁₆ nanocage (M@B₁₆N₁₆, M?=?Li⁺, Na⁺, K⁺, Mg²⁺, Ne, O^2?, S^2?, F^?, Cl^?) and its iso-electronic fullerne M@C₃₂ have been employed to investigate the relation between the trapped atom/ion and electrophilicity of the B₁₆N₁₆ and C₃₂ nanocages. The electrophilicity index, ??, of these endohedral nanocages has been evaluated from the ionization potential and the electron affinity computed by vertical ionization/affinity at the B3LYP/6-311++G(df,pd) level. Obtained results illustrate that the nature of trapped atom/ion affects HOMO-LUMO band gap, global electrophilicity indices and reactivity of B₁₆N₁₆ and C₃₂ nanocages. Encapsulation B₁₆N₁₆ with different atom/ions may be a possible method for modifying HOMO-LUMO energy gap, electrophilicity and so chemical characteristics of and C₃₂ nanocages.     

On weakly symmetric Finsler spaces

In this paper, we study weakly symmetric Finsler spaces. We first study an existence theorem of weakly symmetric Finsler spaces. Then we study some geometric properties of these spaces and prove that any such space can be written as a coset space of a Lie group with an invariant Finsler metric. Finally we show that each weakly symmetric Finsler space is of Berwald type.     

P2O5/SiO2‐Catalyzed One‐Pot Synthesis of Amides from Ketones via Schmidt Reaction under Microwave Irradiation in Dry Media

A facile and efficient method for the preparation of amides from ketones by the Schmidt reaction is described for the first time using P₂O₅/SiO₂ and sodium azide under solvent‐free microwave irradiation. Advantages of this procedure are selectivity, good yields, a simple operation, short reaction time, and solvent‐free conditions.     

Novel BC2N Nanocages: A DFT Investigation

We modeled and studied three types of novel B₁₂C₂₄N₁₂ cages. The structure of these cages was inspired by those of BC₂N nanotubes and the B₂₄N₂₄ fulborene skeleton. Density functional theory was used to investigate the various properties of the cages. All three isomers of B₁₂C₂₄N₁₂ were vibrationally stable. The highest occupied molecular orbital‐lowest unoccupied molecular orbital band gap was dependent on the BC₂N cage type. The B₁₂C₂₄N₁₂‐II cage was the most favorable nanocage and exhibited a large electric dipole moment. Natural bonding orbital (NBO) analysis confirmed the existence of lone pairs and unoccupied orbitals in the B₁₂C₂₄N₁₂ cages. New donor–acceptor interactions of natural MOs (Molecular Orbitals) were observed in BC₂N nanocages. The NBO and atomic polar tensor charges appeared to be fairly well correlated, showing that atomic charges can be obtained at a lower computational cost in this way.     

One-pot and efficient synthesis of triazolo[1,2-a]indazole-triones via reaction of arylaldehydes with urazole and dimedone catalyzed by silica nanoparticles prepared from rice husk

A novel synthesis of triazolo[1,2-a]indazole-1,3,8-trione derivatives by reaction of urazole, dimedone and aromatic aldehydes under conventional heating and microwave irradiation and solvent-free conditions using silica nanoparticles prepared from rice husk ash as catalyst is described. The new method features high yields, multicomponent reactions and environmental friendliness.     

Investigation of the interaction of ethyl acetoacetate with nano alumina particle as Lewis acid in acetonitrile solvent

The enol form of ethyl acetoacetate (EAA) displays interesting spectroscopic characteristics; this form of ethyl acetylacetate is very important in condensation reaction. In this investigation, we have studied the interactions and the complex formation constants (K _f) with nano alumina (10?C20 nm) particle and alumina (mesh 135) compounds as Lewis acids in the acetonitrile solvent using absorption spectroscopy and related calculations. Furthermore, in this study we calculated the thermodynamic parameters of this reaction. The trend of reactivity of the ethyl acetoacetate (EAA) complexes toward the above Lewis acids, based on the solvent as follows: nano alumina compound > alumina compound.