The Experts below are selected from a list of 29202 Experts worldwide ranked by ideXlab platform
Y J Shi - One of the best experts on this subject based on the ideXlab platform.
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hot wire chemical vapor deposition chemistry in the gas phase and on the catalyst surface with organosilicon compounds
Accounts of Chemical Research, 2015Co-Authors: Y J ShiAbstract:ConspectusHot wire chemical vapor deposition (HWCVD), also referred to as catalytic CVD (Cat-CVD), has been used to produce Si-containing thin films, nanomaterials, and functional polymer coatings that have found wide applications in microelectronic and photovoltaic devices, in automobiles, and in biotechnology. The success of HWCVD is largely due to its various advantages, including high deposition rate, low substrate temperatures, lack of plasma-induced damage, and large-area uniformity. Film growth in HWCVD is induced by reactive species generated from Primary Decomposition on the metal wire or from secondary reactions in the gas phase. In order to achieve a rational and efficient optimization of the process, it is essential to identify the reactive species and to understand the chemical kinetics that govern the production of these precursor species for film growth.In this Account, we report recent progress in unraveling the complex gas-phase reaction chemistry in the HWCVD growth of silicon carbide th...
Yang Zhang - One of the best experts on this subject based on the ideXlab platform.
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multi loop integrand reduction with computational algebraic geometry
arXiv: High Energy Physics - Phenomenology, 2014Co-Authors: Simon Badger, Hjalte Frellesvig, Yang ZhangAbstract:We discuss recent progress in multi-loop integrand reduction methods. Motivated by the possibility of an automated construction of multi-loop amplitudes via generalized unitarity cuts we describe a procedure to obtain a general parameterisation of any multi-loop integrand in a renormalizable gauge theory. The method relies on computational algebraic geometry techniques such as Grobner bases and Primary Decomposition of ideals. We present some results for two and three loop amplitudes obtained with the help of the MACAULAY2 computer algebra system and the Mathematica package BASISDET.
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integrand level reduction of loop amplitudes by computational algebraic geometry methods
Journal of High Energy Physics, 2012Co-Authors: Yang ZhangAbstract:We present an algorithm for the integrand-level reduction of multi-loop amplitudes of renormalizable field theories, based on computational algebraic geometry. This algorithm uses (1) the Grobner basis method to determine the basis for integrand-level reduction, (2) the Primary Decomposition of an ideal to classify all inequivalent solutions of unitarity cuts. The resulting basis and cut solutions can be used to reconstruct the integrand from unitarity cuts, via polynomial fitting techniques. The basis determination part of the algorithm has been implemented in the Mathematica package, BasisDet. The Primary Decomposition part can be readily carried out by algebraic geometry softwares, with the output of the package BasisDet. The algorithm works in both D = 4 and D = 4 − 2ϵ dimensions, and we present some two and three-loop examples of applications of this algorithm.
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an integrand reconstruction method for three loop amplitudes
Journal of High Energy Physics, 2012Co-Authors: Simon Badger, Hjalte Frellesvig, Yang ZhangAbstract:We consider the maximal cut of a three-loop four point function with massless kinematics. By applying Grobner bases and Primary Decomposition we develop a method which extracts all ten propagator master integral coefficients for an arbitrary triple-box configuration via generalized unitarity cuts. As an example we present analytic results for the three loop triple-box contribution to gluon-gluon scattering in Yang-Mills with adjoint fermions and scalars in terms of three master integrals.
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an integrand reconstruction method for three loop amplitudes
arXiv: High Energy Physics - Phenomenology, 2012Co-Authors: Simon Badger, Hjalte Frellesvig, Yang ZhangAbstract:We consider the maximal cut of a three-loop four point function with massless kinematics. By applying Groebner bases and Primary Decomposition we develop a method which extracts all ten propagator master integral coefficients for an arbitrary triple-box configuration via generalized unitarity cuts. As an example we present analytic results for the three loop triple-box contribution to gluon-gluon scattering in Yang-Mills with adjoint fermions and scalars in terms of three master integrals.
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integrand level reduction of loop amplitudes by computational algebraic geometry methods
arXiv: High Energy Physics - Phenomenology, 2012Co-Authors: Yang ZhangAbstract:We present an algorithm for the integrand-level reduction of multi-loop amplitudes of renormalizable field theories, based on computational algebraic geometry. This algorithm uses (1) the Gr\"obner basis method to determine the basis for integrand-level reduction, (2) the Primary Decomposition of an ideal to classify all inequivalent solutions of unitarity cuts. The resulting basis and cut solutions can be used to reconstruct the integrand from unitarity cuts, via polynomial fitting techniques. The basis determination part of the algorithm has been implemented in the Mathematica package, BasisDet. The Primary Decomposition part can be readily carried out by algebraic geometry softwares, with the output of the package BasisDet. The algorithm works in both D=4 and $D=4-2\epsilon$ dimensions, and we present some two and three-loop examples of applications of this algorithm.
Jeroen A Van Bokhoven - One of the best experts on this subject based on the ideXlab platform.
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mechanism of fast pyrolysis of lignin studying model compounds
Journal of Physical Chemistry B, 2014Co-Authors: Victoria B F Custodis, Patrick Hemberger, Jeroen A Van BokhovenAbstract:Fast pyrolysis of lignin is one of the most promising methods to convert the complex and irregular structure of lignin into renewable chemicals and fuel. During pyrolysis the complex set of radical reactions, rearrangements, and eliminations is influenced by temperature, pressure, and the lignin origin and structure. This model compound study aims to understand reaction pathways and how Primary intermediates lead to the observed product selectivity. The pyrolysis microreactor directly connected to the gas chromatograph with a mass spectrometer (py-GC/MS) detects the final products, while imaging photoelectron photoion coincidence (iPEPICO) with VUV synchrotron radiation shows Primary Decomposition radicals. The tested model compounds, diphenylether (DPE) and ortho-methoxyphenol (guaiacol), represent a common lignin linkage and the most present subunit in lignin, respectively. Radical fragments, such as the hydroxycyclopentadienyl radical in guaiacol Decomposition, are identified by mass-selected threshold...
Lidong Zhang - One of the best experts on this subject based on the ideXlab platform.
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Experimental and Kinetic Modeling Study of Nitroethane Pyrolysis at a Low Pressure: Competition Reactions in the Primary Decomposition
2016Co-Authors: Kuiwen Zhang, Peter Glarborg, Xueyao Zhou, Lidong Zhang, Guillaume DaymaAbstract:The pyrolysis of nitroethane has been investigated over the temperature range of 682–1423 K in a plug flow reactor at a low pressure. The major species in the pyrolysis process have been identified and quantified using tunable synchrotron vacuum ultraviolet photoionization mass spectrometry and molecular beam sampling techniques. The rate constants for the Primary pyrolysis of nitroethane as well as those for the Decomposition of the secondary product CH3CHNO2 have been obtained via ab initio calculations. These results have been adopted in a detailed chemical kinetic model, which contains 95 species and 737 reactions. The model was validated against the experimental results with satisfactory agreement for most of the identified and quantified species. Further analysis on the results indicates that both the concerted molecular elimination and C–N bond rupture are significant in the Primary pyrolysis of nitroethane, with the latter channel being more important at high temperatures. The adoption of new Decomposition pathways of CH3CHNO2 has resulted in reasonable predictions for relevant intermediates
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an experimental and modeling study of methyl propanoate pyrolysis at low pressure
Combustion and Flame, 2013Co-Authors: Long Zhao, Mingfeng Xie, Zhanjun Cheng, Jianghuai Cai, Lidong ZhangAbstract:Abstract Methyl propanoate (MP) pyrolysis in a laminar flow reactor was studied at low pressure (30 Torr) within the temperature range from 1000 to 1500 K. About 30 products were detected and identified in the pyrolysis process using the photoionization mass spectrometry, including H 2 , CO, CO 2 , CH 3 OH, CH 2 O, CH 2 CO, C1 to C4 hydrocarbons and radicals (such as CH 3 , C 2 H 5 and C 3 H 3 ). Their mole fraction profiles versus temperature were also measured. For the unimolecular dissociation reactions, the rate constants were calculated by high precision theoretical calculations. Based on the theoretical calculations and measured mole fraction profiles of pyrolysis species, a kinetic model of MP pyrolysis containing 98 species and 493 reactions was developed. The model simulates the Primary Decomposition process well with the calculated rate constants. According to the rate of production analysis, the Decomposition pathways of MP and the formation channels of both oxygenated and hydrocarbon products were discussed. It is concluded that the main Decomposition pathway is MP → CH 2 COOCH 3 → CH 3 CO + CH 2 O → CO.
Tim J Evans - One of the best experts on this subject based on the ideXlab platform.
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Lignocellulosic biomass pyrolysis: A review of product properties and effects of pyrolysis parameters
Renewable and Sustainable Energy Reviews, 2016Co-Authors: Tao Kan, Vladimir Strezov, Tim J EvansAbstract:Pyrolysis is one of the thermochemical technologies for converting biomass into energy and chemical products consisting of liquid bio-oil, solid biochar, and pyrolytic gas. Depending on the heating rate and residence time, biomass pyrolysis can be divided into three main categories slow (conventional), fast and flash pyrolysis mainly aiming at maximising either the bio-oil or biochar yields. Synthesis gas or hydrogen-rich gas can also be the target of biomass pyrolysis. Maximised gas rates can be achieved through the catalytic pyrolysis process, which is now increasingly being developed. Biomass pyrolysis generally follows a three-step mechanism comprising of dehydration, Primary and secondary reactions. Dehydrogenation, depolymerisation, and fragmentation are the main competitive reactions during the Primary Decomposition of biomass. A number of parameters affect the biomass pyrolysis process, yields and properties of products. These include the biomass type, biomass pretreatment (physical, chemical, and biological), reaction atmosphere, temperature, heating rate and vapour residence time. This manuscript gives a general summary of the properties of the pyrolytic products and their analysis methods. Also provided are a review of the parameters that affect biomass pyrolysis and a summary of the state of industrial pyrolysis technologies.
