Quadruple-period ordering in MBE GaAsSb alloys

2003 ◽  
Vol 794 ◽  
Author(s):  
Iskander G. Batyrev ◽  
Andrew G. Norman ◽  
Shengbai Zhang ◽  
Su-Huai Wei
Keyword(s):  
Molecular Beam ◽  
Three Dimensional ◽  
High Growth ◽  
Growth Front ◽  
Theoretical Studies ◽  
Ordered Structure ◽  
Grown Layer ◽  
The Individual ◽  
Experimental And Theoretical Studies ◽  
Ordered Layers

ABSTRACTExperimental and theoretical studies are reported for a quadruple period ordering found in GaAsSb alloy layers grown by molecular beam epitaxy at high growth temperatures. We propose a growth model that accounts for the observed three-dimensional (3D) ordered structure. It is shown that the already-ordered material in the previously grown layer affects the reconstruction of the growth front with respect to the underlying alloy template resulting in the correct stacking of the individual 2D ordered layers into the observed 3D ordered structure.

Experimental and theoretical studies on competitive adsorption of aromatic compounds on reduced graphene oxides

2016 ◽  
Vol 4 (15) ◽  
pp. 5654-5662 ◽  
Author(s):  
Shujun Yu ◽  
Xiangxue Wang ◽  
Yuejie Ai ◽  
Xiaoli Tan ◽  
Tasawar Hayat ◽  
...  
Keyword(s):  
Density Functional ◽  
Competitive Adsorption ◽  
Theoretical Studies ◽  
Batch Experiments ◽  
Graphene Oxides ◽  
Functional Theory ◽  
Reduced Graphene ◽  
Reduced Graphene Oxides ◽  
The Individual ◽  
Experimental And Theoretical Studies

The individual and competitive adsorption of benzene, aniline and naphthylamine on reduced graphene oxides were studied by batch experiments and theoretical density functional theory (DFT).

Experimental and theoretical studies of the three-dimensional structure of human interleukin-4

1991 ◽  
Vol 11 (2) ◽  
pp. 111-119 ◽  
Author(s):  
Benson M. Curtis ◽  
Scott R. Presnell ◽  
Subhashini Srinivasan ◽  
Helmut Sassenfeld ◽  
Ralph Klinke ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Interleukin 4 ◽  
Dimensional Structure ◽  
Theoretical Studies ◽  
Three Dimensional Structure ◽  
Experimental And Theoretical Studies

Semi-automated methods for 3-D reconstruction of macromolecular complexes

1995 ◽  
Vol 53 ◽  
pp. 42-43
Author(s):  
B. Carragher ◽  
M. Whittaker
Keyword(s):  
Three Dimensional ◽  
Time Saving ◽  
Macromolecular Complexes ◽  
Symmetry Properties ◽  
Dimensional Reconstruction ◽  
Experienced Operator ◽  
Projection Images ◽  
The Individual ◽  
Natural Symmetry

Techniques for three-dimensional reconstruction of macromolecular complexes from electron micrographs have been successfully used for many years. These include methods which take advantage of the natural symmetry properties of the structure (for example helical or icosahedral) as well as those that use single axis or other tilting geometries to reconstruct from a set of projection images. These techniques have traditionally relied on a very experienced operator to manually perform the often numerous and time consuming steps required to obtain the final reconstruction. While the guidance and oversight of an experienced and critical operator will always be an essential component of these techniques, recent advances in computer technology, microprocessor controlled microscopes and the availability of high quality CCD cameras have provided the means to automate many of the individual steps.During the acquisition of data automation provides benefits not only in terms of convenience and time saving but also in circumstances where manual procedures limit the quality of the final reconstruction.

Phonetic iconicity in the evaluative morphology of a sample of Indo-European, Niger-Congo and Austronesian languages

2010 ◽  
Vol 3 (2) ◽  
pp. 156-180 ◽  
Author(s):  
Renáta Gregová ◽  
Lívia Körtvélyessy ◽  
Július Zimmermann
Keyword(s):  
Three Dimensional ◽  
Sound Symbolism ◽  
Three Dimensional Model ◽  
Austronesian Languages ◽  
Place Of Articulation ◽  
European Languages ◽  
Phonetic Symbolism ◽  
The Individual ◽  
Core Vocabulary

Universals Archive (Universal #1926) indicates a universal tendency for sound symbolism in reference to the expression of diminutives and augmentatives. The research ( Štekauer et al. 2009 ) carried out on European languages has not proved the tendency at all. Therefore, our research was extended to cover three language families – Indo-European, Niger-Congo and Austronesian. A three-step analysis examining different aspects of phonetic symbolism was carried out on a core vocabulary of 35 lexical items. A research sample was selected out of 60 languages. The evaluative markers were analyzed according to both phonetic classification of vowels and consonants and Ultan's and Niewenhuis' conclusions on the dominance of palatal and post-alveolar consonants in diminutive markers. Finally, the data obtained in our sample languages was evaluated by means of a three-dimensional model illustrating the place of articulation of the individual segments.

The Stabilizing Effect of Pre-Equilibria: A Trifluoromethyl Complex as CF2 Reservoir in Catalytic Olefin Difluorocarbenation

2020 ◽  
Author(s):  
Thomas Louis-Goff ◽  
Huu Vinh Trinh ◽  
Eileen Chen ◽  
Arnold L. Rheingold ◽  
Christian Ehm ◽  
...  
Keyword(s):  
High Selectivity ◽  
Side Reactions ◽  
Theoretical Studies ◽  
Attractive Feature ◽  
Catalyst Recovery ◽  
Wide Range ◽  
Stabilizing Effect ◽  
Experimental And Theoretical Studies

A new, efficient, catalytic difluorocarbenation of olefins to give 1,1-difluorocyclopropanes is presented. The catalyst, an organobismuth complex, uses TMSCF<sub>3</sub> as a stoichiometric difluorocarbene source. We demonstrate both the viability and robustness of this reaction over a wide range of alkenes and alkynes, including electron-poor alkenes, to generate the corresponding 1,1-difluorocyclopropanes and 1,1-difluorocyclopropenes. Ease of catalyst recovery from the reaction mixture is another attractive feature of this method. In depth experimental and theoretical studies showed that the key difluorocarbene-generating step proceeds through a bismuth non-redox synchronous mechanism generating a highly reactive free CF<sub>2</sub> in an endergonic pre-equilibrium. It is the reversibility when generating the difluorocarbene that accounts for the high selectivity, while minimizing CF<sub>2</sub>-recombination side-reactions.

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