A new family of perovskites RMnMnTaO6 has been synthesised at high pressure for representative R ?= ?La, Nd, Sm, Eu, Gd, Y and Lu that span the whole rare earth series. The structure type changes from tetragonal P42/n double perovskite (DDPv) with columnar R3+/Mn2+ cation order (R Sm) to monoclinic P21/n (DPv) (R0.5Mn0.5)2MnTaO6 ?Sm, Y, Lu) as R3+ size decreases. No antisite disorder or nonstoi...

Under appropriate conditions, the interaction of the plant alkaloid ryanodine with a single cardiac sarcoplasmic reticulum Ca(2+)-release channel results in a profound modification of both channel gating and conduction. On modification, the channel undergoes a dramatic increase in open probability and a change in single-channel conductance. In this paper we aim to provide a mechanistic framewor...

the control of biological, hydrological and geochemical cycles of soil is the key part of the earth system. the objective of this research was to evaluate changes in soil chemical properties due to deforestation occurred in the gazafolya village, merek watershed, kermanshah province, iran. toward this attempt, 35 soil samples were collected from top soil layer using auger in early june, 2013. s...

Rare-earth based luminescent materials are key functional components for the rational design of light-conversion smart devices. Stable Eu3+-doped strontium fluoride (SrF2) nanoparticles were prepared at room temperature in ethylene glycol. Their luminescence depends on Eu content and changes after heat treatment. The crystallinity heat-treated material increases comparison with as-synthesized s...

karkhe watershed (kw) with more than 5 million hectares recently encountered many problems in the natural, social and man-made habitats. unsuitable use of land, soil erosion and lack of rainfall are the most destructive factors in this watershed affecting the whole region fundamentally. as expected, these problems have caused a considerable fall in biodiversity in fauna and flora, a decrease in...

Some new compounds based on bis-benzimidazole moieties have been synthesized and characterized by IR and NMR spectroscopies. The ability of 3a in transition metal cation sensing such as Co2+, Ni2+, Zn2+, Mn2+, Fe2+ and Cu2+ have been investigated by Uv-vis and fluorescence spectroscopy in methanol solvent. The complexation constants and complex stoichiometry of Cu2+ have been determined. The ex...

Currently, there is a drive to develop the organoelement chemistry of sodium, most abundant alkali metal on earth, as an alternative that rarer lithium, with prime focus sustainability. Organolithium compounds have been essential success synthetic for more than century, although their implementation has essentially confined stoichiometric synthesis. Here, we report synthetic, structural, cataly...

As a result of a general study on the partition column chromatography of insulin, it was noted that a number of commercial samples of crystalline insulin gave elution curves which indicated the presence of at least two components in the eluted fractions (3, 4). The solvent systems used in these studies were similar to those that had been reported by Harfenist and Craig in their countercurrent d...