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991.
In this article,we study the generalized Riemann problem for a scalar nonconvex Chapman-Jouguet combustion model in a neighborhood of the origin (t > 0) on the (x,t) plane.We focus our attention to the... 相似文献
992.
Alexander Gluhovsky Christopher Tong 《Communications in Nonlinear Science & Numerical Simulation》2012,17(7):3112-3113
Extensive prior literature (not referenced in the paper) on links between mechanical gyrostats and nonlinear dynamical systems with strange attractors is called to the readers’ attention. 相似文献
993.
There has been much research and speculation recently on the nature of radiation induced defects in zirconium and its alloys, and in particular on the absence of voids at high fluences and temperatures in the range 0.3 to 0.5 T m (T m is the absolute melting temperature). Wolfenden and Farrell1 have reviewed the evidence and suggest that α-Zr has so far resisted void formation during neutron irradiation because of: (a) the absence of a dislocation (loop or tangle) structure and/or (b) a low insoluble gas (e.g. helium) content. 相似文献
994.
Dr. Quentin Bonnin Tereza Edlová Dr. E. Daiann Sosa Carrizo Prof. Dr. Paul Fleurat-Lessard Dr. Stéphane Brandès Dr. Hélène Cattey Dr. Philippe Richard Prof. Dr. Pierre Le Gendre Dr. Adrien T. Normand 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(72):18175-18187
Cationic amidotitanocene complexes [Cp2Ti(NPhAr)][B(C6F5)4] (Cp=η5-C5H5; Ar=phenyl ( 1 a ), p-tolyl ( 1 b ), p-anisyl ( 1 c )) were isolated. The bonding situation was studied by DFT (Density Functional Theory) using EDA-NOCV (Energy Decomposition Analysis with Natural Orbitals for Chemical Valence). The polar Ti−N bond in 1 a–c features an unusual inversion of σ and π bond strengths responsible for the balance between stability and reactivity in these coordinatively unsaturated species. In solution, 1 a–c undergo photolytic Ti−N cleavage to release Ti(III) species and aminyl radicals ⋅ NPhAr. Reaction of 1 b with H3BNHMe2 results in fast homolytic Ti−N cleavage to give [Cp2Ti(H3BNHMe2)][B(C6F5)4] ( 3 ). 1 a–c are highly active precatalysts in olefin hydrogenation and silanes/amines cross-dehydrogenative coupling, whilst 3 efficiently catalyzes amine-borane dehydrogenation. The mechanism of olefin hydrogenation was studied by DFT and the cooperative H2 activation key step was disclosed using the Activation Strain Model (ASM). 相似文献
995.
Mahasin F. Hadi Al-Kadhemy 《Physica B: Condensed Matter》2012,407(17):3335-3338
The influence of the thickness of CdTe/n-Ge heterojunction photodetectors on I–V curves was studied experimentally and theoretically. The thicknesses of the CdTe thin films were 110, 130, 150, and 200 nm. The power intensity of illumination was 150 mW/cm2. Increasing the thickness led to an increase in photocurrent. 相似文献
996.
Infrastructure systems such as power and water supplies make up the cornerstone of modern society which is essential for the functioning of a society and its economy. They become more and more interconnected and interdependent with the development of scientific technology and social economy. Risk and vulnerability analysis of interdependent infrastructures for security considerations has become an important subject, and some achievements have been made in this area. Since different infrastructure systems have different structural and functional properties, there is no universal all-encompassing ‘silver bullet solution’ to the problem of analyzing the vulnerability associated with interdependent infrastructure systems. So a framework of analysis is required. This paper takes the power and water systems of a major city in China as an example and develops a framework for the analysis of the vulnerability of interdependent infrastructure systems. Four interface design strategies based on distance, betweenness, degree, and clustering coefficient are constructed. Then two types of vulnerability (long-term vulnerability and focused vulnerability) are illustrated and analyzed. Finally, a method for ranking critical components in interdependent infrastructures is given for protection purposes. It is concluded that the framework proposed here is useful for vulnerability analysis of interdependent systems and it will be helpful for the system owners to make better decisions on infrastructure design and protection. 相似文献
997.
Alireza Bananej Amir Hassanpour Hossein Razzaghi Mehdí Vaez zade Ali Mohammadi 《Optics & Laser Technology》2010,42(8):1187-1192
Monolayer ZrO2 and TiO2 films were prepared on BK7 glass by physical vapor deposition (PVD) and were subsequently annealed for 1 h at 300 °C. By using the transmission spectra of two samples and the envelope method, the refractive index dispersion and extinction coefficients have been calculated. Laser induced damage threshold (LIDT) measurement shows that despite slight differences between the extinction coefficients of the two samples, the LIDT parameter of the ZrO2 film is greater than that of the TiO2 film. This fact leads us to consider thermal conductivity as an important parameter for interpreting the LIDT difference. According to our theoretical analysis, as a consequence of increase in the number of thermal barriers along poorer film, its thermal conductivity, and hence LIDT, decreased, which is in agreement with our experimental results. The measured porosity of the two samples shows higher porosity for TiO2 single layer, which is in agreement with atomic force (AFM) images. The gradual and smooth damage morphology of ZrO2 observed in optical images implies higher thermal conductivity than TiO2. 相似文献
998.
用流变震荡模式研究了10 wt%浓度的弹道明胶在冷却和等温下的老化行为.对明胶从sol-gel点冷却到某个目标温度的过程,通过不同冷却速率的实验,建了一个弹性模量与温度的线性关系.不同温度下明胶的等温老化实验表明,弹性模量-时间曲线具有相似的形状.依据Normand提出的二级反应动力学模型,引入一个表征明胶老化行为的速率常数,构建了一个预测弹道明胶在老化初级阶段的弹性模量演化的模型.该模型中模量-温度关系在初始和无穷大时是直线,其他模量-温度线是近似直线,并交于sol-gel点.老化速率常数和过冷度之间符合Flory-Weaver方程.对弹性模量和老化时间进行归一化处理,可将不同温度下的老化曲线叠加成一条主曲线. 相似文献
999.
A generalization of the Oberbeck–Boussinesq model consisting of a system of steady state multivalued partial differential equations for incompressible, generalized Newtonian of the p-power type, viscous flow coupled with the nonlinear heat equation is studied in a bounded domain. The existence of a weak solution is proved by combining the surjectivity method for operator inclusions and a fixed point technique. 相似文献
1000.
For detailed study of complex chemical reactions mechanisms experiment is conducted for selected private reactions. This causes a problem of kinetic parameters getting—the same set of rate constants must describe both public and private reaction stages, and also a general mechanism. In this paper, solution of this problem for a reaction of olefins hydroalumination is proposed. To optimize the computational process a methodology of parallelization is elaborated. On the base of parallel computations, a kinetic model for the reaction assigned is constructed, and on its base, the physical and chemical conclusions about reaction mechanism are done. 相似文献