Download or read book Theoretical Studies of Silicon and Related Elements Reaction Surfaces and Dynamics of Potential High Energy Species written by and published by . This book was released on 1993 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objectives of this project were to study a variety of main group compounds and their reactions, with special emphasis on the chemistry of silicon and how the behavior of this element relates to problems of Air Force interest. The process investigated included the detailed mechanism of the chemical vapor deposition (CVD) process, the polymerization mechanism of silanols, the role of hypervalent silicon in polymerization mechanisms, and the relationship of hypervalent silicon to hypervalent aluminum. Toward the end of the project, the effort broadened into investigations of the interactions of silicon with transition metals, in view of the role of the transition metals as catalysts in a variety of reactions. The second main area of investigation has been the design and study of high energy content molecules, with the intent of designing new potentially higher energy fuels. One compound that had been previously proposed by others, the asymmetric dimer of NO, was shown by us to predissociate. So, this compound will not be a realistic HEDM compound. We think, however, that other isomers of the NO dimer have greater potential for new fuels, and these possibilities will be explored.
Download or read book Theoretical Studies of Silicon and Related Elements written by and published by . This book was released on 2002 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: On the theoretical side, a new highly scalable code for frozen core second order perturbation theory gradients for closed shell molecules has been developed. The development of analogous codes for molecules with unpaired electrons is in progress. A sequential unrestricted code for this purposed has been completed. The derivation for the spin-restricted open shell second order perturbation theory gradients has been completed, and a paper describing this derivation has now been accepted. Other important developments are new convergence methods for MCSCF wave functions that facilitate MCSCF calculations on large molecules, the derivation of gradients for multi-reference second order perturbation theory, the development and implementation of a full-CI method that is amenable to parallelization, further developments of our effective fragment potential (EFP) method for studying solvation and liquid behavior, the development of molecular dynamics and Monte Carlo methods to facilitate the study of solvation and liquid behavior, the development and implementation of a new method for producing global potential energy surfaces from sets of ab initio points, the development and implementation of both grid-based and gridless approaches to density functional theory, and the development and implementation of several MCSCF-based approaches to spin-orbit coupling. With regard to applications, considerable progress has been made in our understanding of the mechanisms for formation of POSS (polyhedral oligomeric silsesquioxanes) and the possibility of passing small gas molecules though them. POSS titanium analogs have also been studied, as have the hydrosilation and bis-silylation reactions. Other applications include studies of surface chemistry, several silicon systems and studies of the behavior of water clusters.
Download or read book Theoretical Studies of Silicon Surfaces Using Finite Clusters written by Antonio Redondo-Muiño and published by . This book was released on 1977 with total page 474 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Theoretical Studies of Silicon and Metallasilicon Compounds written by Monica Kosa and published by . This book was released on 2007 with total page 187 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Theoretical Studies in Silicon Chemistry written by Roger Scott Grev and published by . This book was released on 1986 with total page 200 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Chemistry of Silicon and Related Elements and High Energy Density written by and published by . This book was released on 1995 with total page 27 pages. Available in PDF, EPUB and Kindle. Book excerpt: The main goals in the previous grant period have been to develop new, more effective methods for performing accurate ab initio electronic structure calculations and to use these methods for the prediction of molecular structure, bonding and reactivity, especially for main group species and reactions of interest to the Air Force. From the theoretical point of view, the principle accomplishments have been extensive development of approaches and codes for performing electronic structure calculations in parallel, continued development of methods for interfacing electronic structure calculations with dynamics, initial studies of the possibility of splicing together different levels of electronic structure theory, and the development of a new model for treating solvation. Applications have ranged from the development of very accurate and extensive potential energy surfaces for A + HB reactions (to interface with the experiments of Neumark and Zare) to the role of catalysts in the hydrosilation reaction to extensive studies of reactions involved in both main group and transition metal chemical vapor deposition (CVD) to broad-based studies of cage molecules (using our new parallel capabilities) that are potential precursors for new materials, electronic and optical devices, and catalysts. A new area that we have entered into is a series of systematic calculations on transition metal (TM) - main group (MG) compounds and their reactions, with particular emphasis on their roles as catalysts and in such important areas as CVD. jg p3.
Download or read book Theoretical Studies of Silicon Chemistry written by and published by . This book was released on 1990 with total page 53 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Organosilicon Compounds written by Vladimir Ya Lee and published by Academic Press. This book was released on 2017-08-22 with total page 758 pages. Available in PDF, EPUB and Kindle. Book excerpt: Organosilicon Compounds: Theory and Experiment (Synthesis), volume 1, comprises two parts. The first part, Theory, covers state-of-the-art computational treatments of unusual nonstandard organosilicon compounds that classical bonding theory fails to describe adequately. The second part, Experiment (Synthesis), describes recent synthetic advances in the preparation of a variety of organosilicon compounds with different coordination numbers of the central silicon: from tetracoordinate to low-coordinate to hypercoordinate derivatives. Organosilicon Compounds: From Theory to Synthesis to Applications provides a comprehensive overview of this important area of organic and organometallic chemistry, dealing with compounds containing carbon–silicon bonds. This field, which includes compounds that are widely encountered in commercial products such as in the fabrication of sealants, adhesives, and coatings, has seen many milestone discoveries reported during the last two decades. Beginning with the theoretical aspects of organosilicon compounds' structure and bonding, the book then explores their synthetic aspects, including main group element organosilicon compounds, transition metal complexes, silicon cages and clusters, low-coordinate organosilicon derivatives (cations, radicals, anions, multiple bonds to silicon, silaaromatics), and more. Next, readers will find valuable sections that explore physical and chemical properties of organosilicon compounds by means of X-ray crystallography, 29Si NMR spectroscopy, photoelectron spectroscopy, and other methods. Finally, the work delves into applications for industrial uses and in many related fields, such as polymers, material science, nanotechnology, bioorganics, and medicinal silicon chemistry. - Features valuable contributions from prominent experts that cover both fundamental (theoretical, synthetic, physico-chemical) and applied (material science, applications) aspects of modern organosilicon chemistry - Covers important breakthroughs in the field, along with the historically significant achievements of the past - Includes applied information for a wide range of specialists, from junior and senior researchers (from both academia and industry) - Ideal reference for those working in organometallic, organosilicon, main group element, transition metal, and industrial silicon chemistry, as well as those from interdisciplinary fields, such as polymer, material science, and nanotechnology
Download or read book Silicon in Agriculture written by Yongchao Liang and published by Springer. This book was released on 2015-06-18 with total page 250 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book mainly presents the current state of knowledge on the use of of Silicon (Si) in agriculture, including plants, soils and fertilizers. At the same time, it discusses the future interdisciplinary research that will be needed to further our knowledge and potential applications of Si in agriculture and in the environmental sciences in general. As the second most abundant element both on the surface of the Earth’s crust and in soils, Si is an agronomically essential or quasi-essential element for improving the yield and quality of crops. Addressing the use of Si in agriculture in both theory and practice, the book is primarily intended for graduate students and researchers in various fields of the agricultural, biological, and environmental sciences, as well as for agronomic and fertilizer industry experts and advisors. Dr. Yongchao Liang is a full professor at the College of Environmental and Resource Sciences of the Zhejiang University, Hangzhou, China. Dr. Miroslav Nikolic is a research professor at the Institute for Multidisciplinary Research of the University of Belgrade, Serbia. Dr. Richard Bélanger is a full professor at the Department of Plant Pathology of the Laval University, Canada and holder of a Canada Research Chair in plant protection. Dr. Haijun Gong is a full professor at College of Horticulture, Northwest A&F University, China. Dr. Alin Song is an associate professor at Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, China.
Download or read book Second Order Non linear Optics of Silicon and Silicon Nanostructures written by O. A. Aktsipetrov and published by CRC Press. This book was released on 2018-09-03 with total page 582 pages. Available in PDF, EPUB and Kindle. Book excerpt: The theory and practice of the non-linear optics of silicon are inextricably linked with a variety of areas of solid state physics, particularly semiconductor physics. However, the current literature linking these fields is scattered across various sources and is lacking in depth. Second Order Non-linear Optics of Silicon and Silicon Nanostructures describes the physical properties of silicon as they apply to non-linear optics while also covering details of the physics of semiconductors. The book contains six chapters that focus on: The physical properties and linear optics of silicon Basic theoretical concepts of reflected second harmonics (RSH) The authors’ theory of the generation of RSH at the non-linear medium–linear medium interface An analytical review of work on the non-linear optics of silicon The results of non-linear optical studies of silicon nanostructures A theory of photoinduced electronic processes in semiconductors and their influence on RSH generation The book also includes methodological problems and a significant amount of reference data. It not only reflects the current state of research but also provides a single, thorough source of introductory information for those who are becoming familiar with non-linear optics. Second Order Non-linear Optics of Silicon and Silicon Nanostructures is a valuable contribution to the fields of non-linear optics, semiconductor physics, and microelectronics, as well as a useful resource for a wide range of readers, from undergraduates to researchers.
Download or read book Theoretical Studies of Amorphous Silicon and Hydrogenated Amorphous Silicon with Molecular Dynamics Simulations written by Inhee Kwon and published by . This book was released on 1991 with total page 204 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Theoretical Studies of the Chemistry and Physics of Oxygen in Silicon written by Lawrence C. Snyder and published by . This book was released on 1988 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: We have developed a cyclic-cluster program to compute the structure and properties of defects in crystalline solids. We have found the semi-empirical electronic structure method MINDO/3 to give the best account of the structure, stability and states near the gap for defects in silicon. We have applied the cyclic cluster program to describe the chemistry and physics of hydrogen and oxygen in a silicon crystal. We have concluded that a di-ylid is a promising candidate for the core of the 450 oxygen thermal donor in silicon. We have discovered that a four-member ring containing two oxygen atoms is likely to diffuse much faster than interstitial oxygen in silicon. We have applied perturbation theory to give a qualitative explanation of the ladder of effective mass states associated with oxygen clusters in silicon and germanium. Keywords: Semiconductor theory, Silicon defects, Oxygen thermal donors. (JES).
Download or read book Theoretical Studies of Amorphous and Paracrystalline Silicon written by Serge Nakhmanson and published by . This book was released on 2001 with total page 380 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Porous Silicon written by George C. John and published by . This book was released on 1995 with total page 59 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1994 with total page 1028 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.
Download or read book Theoretical Studies of Homogeneous and Heterogeneous Reactions in Silicon Systems written by and published by . This book was released on 1991 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report summarizes the results of research conducted under AFOSR support with particular emphasis on investigations carried out during three-year period. The research reviewed includes homogeneous and heterogeneous processes of particular importance in the chemical vapor deposition (CVD) of silicon from silanes and disilanes, the study of chemical processes occurring under conditions of close confinement, non-statistical dynamics and intramolecular energy transfer processes. New methods for (1) obtaining potential energy surfaces for highly complex systems, (2) simulation of the effects of relaxation to the bulk in surface systems, (3) perturbation studies of gas surface scattering, (4) computation of two dimensional surface tunneling rates, (5) highly efficient variational phase space theory calculation of microconical unimolecular reaction rates, and (6) the computation of intramolecular vibrational relaxation rates are also described.
Download or read book New Theoretical Studies of Structure and Defects in Hydrogenated Amorphous Silicon written by Douglas Clippinger Allan and published by . This book was released on 1982 with total page 104 pages. Available in PDF, EPUB and Kindle. Book excerpt:
