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This paper deals with the determination of an initial condition in degenerate hyperbolic equation from final observations. With the aim of reducing the execution time, this inverse problem is solved using an approach based on double regularization: a Tikhonov’s regularization and regularization in equation by viscose-elasticity. So, we obtain a sequence of weak solutions of degenerate linear viscose-elastic problems. Firstly, we prove the existence and uniqueness of each term of this sequence. Secondly, we prove the convergence of this sequence to the weak solution of the initial problem. Also we present some numerical experiments to show the performance of this approach. 相似文献
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The analysis for morphological evolution and crystallography of degenerate pearlite in 100Mn13 steel
During approximate 773 K aging treatment of 100Mn13 steel, degenerate pearlite will occur and evolve into lamellar pearlite during growth process. The microstructures of degenerate pearlite and its evolutionary lamellar pearlite are observed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results show that after 748 K, 773 K and 798 K aging, degenerate pearlites occur at grain boundary. At growth front of degenerate pearlite forming at 773 K and 798 K, pearlite presents a morphology of short lamellae of carbide and ferrite, indicating a trend of developing into lamellar pearlite. The higher the temperature is, the more obvious the trend is, and even a conventional lamellar pearlite has developed. However, there is no morphological evolution for degenerate pearlite forming at 748 K aging. Besides, the constituents of degenerate pearlite is identified as M23C6 and ferrite, and Kurdjumov-Sachs orientation relationship exists between them, (01 )α//( 1 )M23C6, [111]α//[110]M23C6. This orientation relationship maintains in morphological evolution from degenerate pearlite to lamellar pearlite. 相似文献
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A high-density, low-temperature plasma can be obtained during the compression phase in inertial confinement fusion. When high density and low temperature are reached in the plasma in the fast ignition approach, the plasma electrons can be degenerate. The electronic stopping of a slow ion is smaller than that given by the classical formula, because some transitions between the electron states are forbidden. In this case, bremsstrahlung emission is strongly suppressed and the ignition temperature becomes lower than that in classical plasma. The equations that predict the behavior of these plasmas are different from the classical ones, and this is the main factor in the process of decreasing the ignition temperature of the plasma. In this work, physical conditions of ignition are studied by calculating the effect of radiation loss on the ignition temperature for a simulated fuel pellet, (D/T x / 3 He y ), in degenerate plasma. In fast ignition, the energy needed for obtaining high densities is minimized and the gain can be increased considerably. 相似文献
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《国际聚合物材料杂志》2012,61(3-4):381-449
Abstract Electrooptical properties of polymer-dispersed liquid crystals (LCs) are analyzed from the point of view of the order created by the electric field, dynamic changes of the order (orientation) parameter, and optical transmittivity. Optical phase retardation causes an optical phase shift and is related to thermal effects. Nonlinear optical properties are investigated from the point of view of self-transparency, nonlinear gratings, threshold degenerate wave mixing, optical bistability and second harmonic generation. 相似文献
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对称型席夫碱类二茂铁衍生物的合成与性能研究 总被引:1,自引:0,他引:1
以二茂铁甲醇为原料,经Wittig反应后与2,6-(双胺基)-苯并[1,2-d-4,5-d′]双三唑-4,8(2H,6H)-二酮缩合,合成了一个D-π-A-π-D结构的二茂铁席夫碱类金属有机三阶非线性光学材料。化合物结构经1H NMR,MS表征确认。测定了该化合物的紫外-可见吸收光谱,用简并四波混频(DFWM)检测了其三阶非线性参数,检测波长为800 nm;脉冲宽度为80 fs。该化合物的三阶非线性极化率χ(3)值为3.67×10-13esu(静电单位),分子二阶超极化率γ值为3.49×10-31esu,表明该化合物具有良好的三阶非线性光学性能,优于现有的二茂铁类金属有机材料。探讨了分子结构对三阶非线性光学性能的影响,长共轭链、强电子离域能可提高分子三阶非线性光学性能。 相似文献
9.
Federico C. Buroni Jhonny E. Ortiz Andrés Sáez 《International journal for numerical methods in engineering》2011,86(9):1125-1143
In this paper we develop an alternative boundary element method (BEM) formulation for the analysis of anisotropic three‐dimensional (3D) elastic solids. Our implementation is based on the derivation of explicit expressions for the fundamental solution displacements and tractions, of general validity for any class of anisotropic materials, by means of Stroh formalism and Cauchy's residue theory. The resulting fundamental solution remains valid for mathematical degenerate cases when Stroh's eigenvalues are coincident, meanwhile it does not exhibit numerical instabilities for quasi‐degenerate cases when Stroh's eigenvalues are nearly equal. A multiple pole residue approach is followed, leading to general explicit expressions to evaluate the traction fundamental solution for poles of m‐multiplicity. Despite the existence of general displacement solutions in the literature, and for the sake of completeness, the same approach as for the traction solution is considered to derive the displacement fundamental solution as well. Based on these solutions, an explicit BEM approach for the numerical solution of 3D linear elastic problems for solids with general anisotropic behavior is presented. The analysis of cracked anisotropic solids is also considered. Details on the numerical implementation and its validation for degenerate cases are discussed. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
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This note shows that the complete and the ready simulation preorders do not have a finite inequational basis over the language BCCSP when the set of actions is a singleton. Moreover, the equivalences induced by those preorders do not have a finite (in)equational axiomatization either. These results are in contrast with a claim of finite axiomatizability for those semantics in the literature, which was based on the erroneous assumption that they coincide with complete trace semantics in the presence of a singleton set of actions. 相似文献