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991.
992.
993.
994.
In this paper, the complex short pulse equation and the coupled complex short pulse equations that can describe the ultra-short pulse propagation in optical fibers are investigated. The two complex nonlinear models are turned into multi-component real models by proper transformations. Lie symmetries are obtained via the classical Lie group method, and the results for the coupled complex short pulse equations contain the existing results as particular cases. Based on the linearizing operator and adjoint linearizing operator for the two real systems, adjoint symmetries can be obtained. Explicit conservation laws are constructed using the symmetry/adjoint symmetry pair (SA) method. Relationships between the nonlinear self-adjointness method and the SA method are investigated. 相似文献
995.
二维范德瓦尔斯材料(可简称二维材料)已发展成为备受瞩目的材料大家族,而由其衍生的二维范德瓦尔斯异质结构的集成、性能及应用是现今凝聚态物理和材料科学领域的研究热点之一.二维范德瓦尔斯异质结构为探索丰富多彩的物理效应和新奇的物理现象,以及构建新型的自旋电子学器件提供了灵活而广阔的平台.本文从二维材料的转移技术着手,介绍二维范德瓦尔斯异质结构的构筑、性能及应用.首先,依据湿法转移和干法转移的分类,详细介绍二维范德瓦尔斯异质结构的制备技术,内容包括转移技术的通用设备、常用转移方法的具体操作步骤、三维操纵二维材料的方法、异质界面清洁.随后介绍二维范德瓦尔斯异质结构的性能和应用,重点介绍二维磁性范德瓦尔斯异质结构,并列举在二维范德瓦尔斯磁隧道结和摩尔超晶格领域的应用.因此,二维材料转移技术的发展和优化将进一步助力二维范德瓦尔斯异质结构在基础科学研究和实际应用上取得突破性的成果. 相似文献
996.
汽车空调系统中使用较多的制冷剂是R134a,但其GWP(全球变暖潜能值)高达1300,R1234yf作为一种新型制冷剂,其GWP仅为4,且具有与R134a相似的热力学性质。基于动磁式无油直线压缩机对R1234yf和R134a两种制冷剂的性能进行了试验分析,结果表明,当换热器温度分别为-3℃(蒸发器)、40℃(冷凝器)时,R1234yf和R134a的冷却能力分别为92 W和117 W;在冷凝器温度为50℃时,R1234yf的冷却性能与R134a几乎相同。验证了R1234yf替代R134a的可行性。 相似文献
997.
In this paper, a semi-analytic solution of the problem associated with an elliptic inclusion embedded within an infinite matrix is developed for plane strain deformations. The bonding at the inclusion-matrix interface is assumed to be homogeneously imperfect. The interface is modeled as a spring (interphase) layer with vanishing thickness. The behavior of this interphase layer is based on the assumption that tractions are continuous but displacements are discontinuous across the interface.Complex variable techniques are used to obtain infinite series representations of the stresses which, when evaluated numerically, demonstrate how the peak stress along the inclusion-matrix interface and the average stress inside the inclusion vary with the aspect ratio of the inclusion and a representative parameter h (related to the two interface parameters describing the imperfect interface in two-dimensional elasticity) characterizing the imperfect interface. In addition, and perhaps most significantly, for different aspect ratios of the elliptic inclusion, we identify a specific value (h
*) of the (representative) interface parameter h which corresponds to maximum peak stress along the inclusion-matrix interface. Similarly, for each aspect ratio, we identify a specific value of h (also referred to as h
* in the paper) which corresponds to maximum peak strain energy density along the interface, as defined by Achenbach and Zhu (1990). In each case, we plot the relationship between the new parameter h
*and the aspect ratio of the ellipse. This gives significant and valuable information regarding the failure of the interface using two established failure criteria. 相似文献
998.
999.
A nonlinear perturbed conservative system is discussed. By means of Hadamard's theorem, the existence and uniqueness of the
solution of the continuous problem are proved. When the equation is discreted on the uniform meshes, it is proved that the
corresponding discrete problem has a unique solution. Finally, the accuracy of the numerical solution is considered and a
simple algorithm is provided for solving the nonlinear difference equation.
Communicated by SU Yu-cheng
Biography: LIU Guo-qing (1966-) 相似文献
1000.
A. F. Polyakov D. L. Reviznikov Shen Qing Tang Jinrong Wei Shuru 《Acta Mechanica Sinica》2001,17(3):245-250
Heat and mass transfer of a porous permeable wall in a high temperature gas dynamical flow is considered. Numerical simulation
is conducted on the ground of the conjugate mathematical model which includes filtration and heat transfer equations in a
porous body and boundary layer equations on its surface. Such an approach enables one to take into account complex interaction
between heat and mass transfer in the gasdynamical flow and in the structure subjected to this flow. The main attention is
given to the impact of the intraporous heat transfer intensity on the transpiration cooling efficiency.
The project supported by the National Natural Science Foundation of China (19889209) and Russian Foundation for Basic Research
(97-02-16943) 相似文献