Metastable metal imidazolates: development of targeted syntheses by combining experimental and theoretical investigations of the formation mechanisms

There have Been a number of studies of low-angle, θ < 4°, [10] tilt boundaries in the diamond lattice. Dislocations with Burgers vectors a/2<110>, a/2<112>, a<111> and a<001> have been reported in melt-grown bicrystals of germanium, and dislocations with Burgers vectors a<001> and a/2<112> have been reported in hot-pressed bicrystals of silicon. Most of the dislocations were found to be dissociated, the dissociation widths being dependent on the tilt angle. Possible dissociation schemes and formation mechanisms for the a<001> and a<111> dislocations from the interaction of lattice dislocations have recently been given.The present study reports on the dislocation structure of a 10° [10] tilt boundary in chemically vapor deposited silicon. The dislocations in the boundary were spaced about 1-3nm apart, making them difficult to resolve by conventional diffraction contrast techniques. The dislocation structure was therefore studied by the lattice-fringe imaging technique.

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Formation Mechanisms for Multiply Twinned Particles During Nucleation in the Au/MICA System

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100114049 ◽

1975 ◽

Vol 33 ◽

pp. 84-85

Author(s):

Eal H. Lee ◽

Helmut Poppa

Keyword(s):

Deposition Time ◽

High Vacuum ◽

Dark Field ◽

Ultra High Vacuum ◽

Formation Mechanisms ◽

Heat Treated ◽

Cluster Density ◽

Diffraction Patterns ◽

Crystal Particle ◽

Multiply Twinned Particles

The formation of thin films of gold on mica has been studied in ultra-high vacuum (5xl0-10 torr) . The mica substrates were heat-treated for 24 hours at 375°C, cleaved, and annealed for 15 minutes at the deposition temperature of 300°C prior to deposition. An impingement flux of 3x1013 atoms cm-2 sec-1 was used. These conditions were found to give high number densities of multiple twin particles and are based on a systematic series of nucleation experiments described elsewhere. Individual deposits of varying deposition time were made and examined by bright and dark field TEM after "cleavage preparation" of highly transparent specimens. In the early stages of growth, the films generally consist of small particles which are either single crystals or multiply twinned; a strong preference for multiply twinned particles was found whenever the particle number densities were high. Fig. 1 shows the stable cluster density ns and the variation with deposition time of multiple twin particle and single crystal particle densities, respectively. Corresponding micrographs and diffraction patterns are shown in Fig. 2.

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Experimental and theoretical investigations concerning the magnetooptic effects in special D-type fibres

Journal de Physique IV (Proceedings) ◽

10.1051/jp4:2005129018 ◽

2005 ◽

Vol 129 ◽

pp. 85-90 ◽

Cited By ~ 3

Author(s):

K. Barczak ◽

T. Pustelny ◽

A. Szpakowski ◽

M. Błahut

Keyword(s):

Theoretical Investigations

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Theoretical and experimental research on slip and uplift of the timber-concrete composite beam

BioResources ◽

10.15376/biores.15.3.7079-7099 ◽

2020 ◽

Vol 15 (3) ◽

pp. 7079-7099

Author(s):

Jianying Chen ◽

Guojing He ◽

Xiaodong (Alice) Wang ◽

Jiejun Wang ◽

Jin Yi ◽

...

Keyword(s):

Differential Equations ◽

Deformation Theory ◽

Concrete Slab ◽

Theoretical Calculations ◽

Structural Element ◽

Structural Efficiency ◽

Theoretical Investigations ◽

New Type ◽

Interlayer Slip ◽

Good Agreement

Timber-concrete composite beams are a new type of structural element that is environmentally friendly. The structural efficiency of this kind of beam highly depends on the stiffness of the interlayer connection. The structural efficiency of the composite was evaluated by experimental and theoretical investigations performed on the relative horizontal slip and vertical uplift along the interlayer between composite’s timber and concrete slab. Differential equations were established based on a theoretical analysis of combination effects of interlayer slip and vertical uplift, by using deformation theory of elastics. Subsequently, the differential equations were solved and the magnitude of uplift force at the interlayer was obtained. It was concluded that the theoretical calculations were in good agreement with the results of experimentation.

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Further Insights by Theoretical Investigations of the Multiscale Arlequin Method

International Journal for Multiscale Computational Engineering ◽

10.1615/intjmultcompeng.v6.i3.30 ◽

2008 ◽

Vol 6 (3) ◽

pp. 215-232 ◽

Cited By ~ 38

Author(s):

Hachmi Ben Dhia

Keyword(s):

Theoretical Investigations ◽

Arlequin Method

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Experimental and Theoretical Investigations of Complex Formation of Substituted Phenylazo-Derivatives of Methylphloroglucinol

JOURNAL OF ADVANCES IN CHEMISTRY ◽

10.24297/jac.v12i8.2837 ◽

2016 ◽

Vol 12 (8) ◽

pp. 295-300

Author(s):

Olga Kovalchukova ◽

Amangdam A.T. ◽

Strashnova S.B. ◽

Strashnov P.V. ◽

Romashkina E.P. ◽

...

Keyword(s):

Complex Formation ◽

Organic Ligand ◽

Spectrophotometric Titration ◽

Organic Ligands ◽

Oh Groups ◽

Tautomeric Forms ◽

Theoretical Investigations ◽

Derivatives Of ◽

Theoretical Results ◽

Titration Technique

Using spectrophotometric titration technique, the processes of complex formation of some phenylazo-derivatives of methylphloroglucinol (MPG) containing hydroxo-, nitro- and nitroso-substituents were studied. The spectral criteria of neutral and ionized forms of the organic ligands in their different tautomeric forms were determined.It was detected that the complex formation is accompanied by formation of one or two chelate cycles which involve azo- or nitroso-fragments and neighboring OH-groups of the organic ligands. Different types of coordination lead to different changes in the electronic absorption spectra.The DFT-B3LYP modeling of a Ni(II) complex of α-hydroxyphenylazo MPG established the most probable coordination mode of the organic ligand: tridentate chelating dianion, distorted square coordination of Ni-cations including one water molecule. The theoretical results are in a good accordance with the experimental data.

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Clinical and molecular cytogenetic characterization of two cases of inverted duplication deletion 8p

Nauchno-prakticheskii zhurnal «Medicinskaia genetika» ◽

10.25557/2073-7998.2020.03.41-42 ◽

2020 ◽

pp. 41-42

Author(s):

Д.А. Юрченко ◽

М.Е. Миньженкова ◽

Е.Л. Дадали ◽

Н.В. Шилова

Keyword(s):

Mental Retardation ◽

Congenital Heart ◽

Heart Defects ◽

Clinical Manifestations ◽

Formation Mechanisms ◽

Agenesis Of Corpus Callosum ◽

Molecular Cytogenetic ◽

Inverted Duplication ◽

Cytogenetic Characterization

Синдром инвертированной дупликации короткого плеча хромосомы 8 со смежной терминальной делециенй (inv dup del(8p), ORPHA 96092) - редкая хромосомная аномалия (ХА) с частотой 1/10000-1/30000 живорожденных. В статье представлены клинические и молекулярно-цитогенетические характеристики двух неродственных пациентов с синдромом inv dup del(8p) и уточнены механизмы формирования хромосомного дисбаланса. Inverted duplication deletion 8p syndrome (inv dup del(8p), ORPHA 96092) is a rare chromosomal abnormality with a frequency of 1:10,000 - 30,000 newborns. Clinical manifestations of this syndrome include mental retardation, facial anomalies, hypoplasia/agenesis of corpus callosum, scoliosis and/or kyphosis, hypotonia, congenital heart defects. The article presents the clinical and molecular cytogenetic characteristics of two patients with inv dup del (8p) syndrome and clarifies the formation mechanisms.

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Substituent Effects on the Thermal Decomposition of Phosphate Esters on Ferrous Surfaces

10.26434/chemrxiv.11418978.v1 ◽

2019 ◽

Author(s):

James Ewen ◽

Carlos Ayestaran Latorre ◽

Arash Khajeh ◽

Joshua Moore ◽

Joseph Remias ◽

...

Keyword(s):

Thermal Decomposition ◽

Film Formation ◽

Substituent Effects ◽

Vapour Phase ◽

Industrial Applications ◽

Phosphate Esters ◽

Antiwear Additives ◽

Formation Mechanisms ◽

Phosphate Ester ◽

Wide Range

Phosphate esters have a wide range of industrial applications, for example in tribology where they are used as vapour phase lubricants and antiwear additives. To rationally design phosphate esters with improved tribological performance, an atomic-level understanding of their film formation mechanisms is required. One important aspect is the thermal decomposition of phosphate esters on steel surfaces, since this initiates film formation. In this study, ReaxFF molecular dynamics simulations are used to study the thermal decomposition of phosphate esters with different substituents on several ferrous surfaces. On Fe3O4(001) and α-Fe(110), chemisorption interactions between the phosphate esters and the surfaces occur even at room temperature, and the number of molecule-surface bonds increases as the temperature is increased from 300 to 1000 K. Conversely, on hydroxylated, amorphous Fe3O4, most of the molecules are physisorbed, even at high temperature. Thermal decomposition rates were much higher on Fe3O4(001) and particularly α-Fe(110) compared to hydroxylated, amorphous Fe3O4. This suggests that water passivates ferrous surfaces and inhibits phosphate ester chemisorption, decomposition, and ultimately film formation. On Fe3O4(001), thermal decomposition proceeds mainly through C-O cleavage (to form surface alkyl and aryl groups) and C-H cleavage (to form surface hydroxyls). The onset temperature for C-O cleavage on Fe3O4(001) increases in the order: tertiary alkyl < secondary alkyl < primary linear alkyl ≈ primary branched alkyl < aryl. This order is in agreement with experimental observations for the thermal stability of antiwear additives with similar substituents. The results highlight surface and substituent effects on the thermal decomposition of phosphate esters which should be helpful for the design of new molecules with improved performance.

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