Monoclinic polymorph of poly[[di-μ-aqua-triaquadi-μ-oxalato-barium(II)­copper(II)] monohydrate]

A monoclinic polymorph of the title compound, {[BaCu(C2O4)2(H2O)5]·H2O}n, is reported. The structure is best described as a coordination polymer where the CuII and BaII centers are coordinated by five and nine O atoms, respectively, in capped quadratic antiprismatic and tetragonal pyramidal geometries. The polymerization arises due to the presence of bridging mono- and bidentate oxalate ligands as well as bridging water mol­ecules. The crystal structure is consolidated by a three-dimensional network of hydrogen bonding

{[Na1(μ-H2O)Na2]2[(C2O4)2Cr(μ-OH)2Cr(C2O4)2]·H2O}n, a novel hydrated form

The unit cell of the title compound, poly[[μ-aqua-μ-hydroxido-di-μ-oxalato-chromium(III)disodium] monohydrate], {[CrNa2(C2O4)2(OH)(H2O)]·H2O}n, contains four [Na1(μ-H2O)Na2][(C2O4)2Cr(μ-OH)·H2O] formula units, each of which consists of two crystallographically independent Na+ sites (bridged by one aqua ligand), one half of a centrosymmetric di-μ-hydroxido-bis­[cis-bis­(oxalato)chromate(III)] dimer, [(C2O4)2Cr(μ-OH)2Cr(C2O4)2]4−, and one uncoordin­ated water mol­ecule. The structure is best described as a coordination polymer in which the three-dimensional lattice framework is realized by the inter­connection of the metallic atoms via the O atoms of the aqua, hydroxide and oxalate ligands. One Na atom is hepta­coordinated by one water, one hydroxide and five oxalate O atoms, whilst the other is penta­coordinated by one water and four oxalate O atoms. The coordination around the Cr3+ sites is pseudo-octa­hedral, involving four aqua and two hydroxide O atoms. Adjacent Na atoms are separated by 3.593 (2) Å, whereas the intra­dimer Cr⋯Cr spacing is 2.978 (1) Å. The crystal structure is consolidated by extended relatively weak O—H⋯O hydrogen bonding with O⋯O distances ranging from 2.808 (4) to 3.276 (5) Å

Hayattan sahifeler

Hüseyin Rahmi'nin Ati'de tefrika edilen Hayattan Sahifeler adlı roman

Разработка методов модификации структуры и свойств силумина заэвтектического состава

Объектом исследования является заэвтектический силумин, подвергнутый модифицированию ионно-электронно-плазменными методами. Цель работы – разработка ионно-электронно-плазменного метода модифицирования структуры и свойств заэвтектического силумина. В результате исследования выявлены оптимальные режимы обработки образцов, позволяющие в разы повысить эксплуатационные, механических и трибологические характеристики силумина. Модифицированные материалы отличаются высоким уровнем дисперсности и однородности структуры, увеличивается твердость и износостоойкость по сравнению с исходными образцами.The object of the study is the hypereutectic silumin, subjected to modification by ion-electron-plasma methods. The aim of this work is to develop an ion-electron-plasma method for modifying the structure and properties of hypereutectic silumin. Optimal treatment modes were revealed as a result of the study. Mechanical and tribological silumin`s characteristics were improved. Modified materials have a high degree of dispersion and homogeneity of the structure, hardness and wear resistance increase in comparison with the initial samples

Crystal structure of 4-(dimethylamino)pyridinium cis-diaquabis(oxalato-κ2O,O′)ferrate(III) hemihydrate

The FeIII ions in the hybrid title salt, (C7H11N2)[Fe(C2O4)2(H2O)2]·0.5H2O, show a distorted octahedral coordination environment, with four O atoms from two chelating oxalate dianions and two O atoms from two cis aqua ligands. The average Fe—O(oxalate) bond length [2.00 (2) Å] is shorter than the average Fe—O(water) bond length [2.027 (19) Å]. The ionic components are connected via intermolecular N—H...O and O—H...O hydrogen bonds into a three-dimensional network

Анализ эффективности проведения гидроразрыва пласта на Ямбургском нефтегазоконденсатном месторождении (ЯНАО)

Цель данной работы – определить, насколько целесообразно проведение ГРП с технологической и экономической точки зрения, выявить главные аспекты, проанализировать эффективность данного метода на N–ом нефтегазоконденсатном месторождении. Основными задачами является: освещение сущности ГРП как метода интенсификации притока на N–ом нефтегазоконденсатном месторождении; анализ основных характеристик процесса ГРП, с целью определения эффективности данного метода; так же проведение экономического расчета ГРП для определения рентабельности данного метода. По окончанию выполнения поставленных задач можно будет судить о том, на сколько эффективно проведение ГРП на N–ом месторождении.The purpose of this paper is to determine the feasibility of the Hydraulic fracturing treatment from a technological and economic point of view, to identify the main aspects, to analyze the method at the N oil and gas condensate hall. The main tasks are: to illuminate the nature of the hydraulic fracturing as a method of intensifying the inflow at the N oil and gas condensate hall; Analysis of the main characteristics of the fracturing process, in order to determine the effectiveness of this method; In the same way, the economic calculation of the hydraulic fracturing is carried out to determine the variability of this method. After the completion of the tasks, it will be possible to judge how efficient the hydraulic fracturing at the N field is

Sequenzanalyse als Methode zur Darstellung sektorenübergreifender Versorgungspfade am Beispiel von Herzinsuffizienz

International audienceThe dimeric copper(II) complex [Cu(C2O4)(H2oxado)(H2O)]2 (1), where H2oxado = oxamide dioxime, has been synthesized in water and characterized by elemental and thermal analyses, IR spectroscopy, and single-crystal X-ray diffraction. Complex 1 is composed of two neutral [Cu(C2O4)(H2oxado)(H2O)] entities connected by Cu–O bonds between oxalate oxygen atoms and copper(II) ions, thereby producing a centrosymmetric dimer, with the Cu(II) centers exhibiting a strongly distorted octahedral coordination. Neighboring dimers are hydrogen-bonded through O–H⋯O interactions leading overall to a layer structure. Thermal analyses of complex 1 showed two significant weight losses corresponding to the coordinated water molecules, followed by the decomposition of the network. Variable-temperature (10–300K) magnetic susceptibility measurements revealed very weak antiferromagnetic interactions (θ =−0.86  K from Curie–Weiss law behavior) within the dinuclear unit