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61.
Uncertainties are unavoidable in practical engineering, and phononic crystals are no exception. In this paper, the uncertainties are treated as the interval parameters,and an interval phononic crystal beam model is established. A perturbation-based interval finite element method(P-IFEM) and an affine-based interval finite element method(A-IFEM) are proposed to study the dynamic response of this interval phononic crystal beam, based on which an interval vibration transmission analysis can be easi... 相似文献
62.
Zan Ting-quan 《应用数学和力学(英文版)》1987,8(8):785-792
In this paper, the author describes, and comments on the traditional thermal theory on artificial ground freezing, and points out its important significance and shortcomings. The frozen-wall is analysed by system analysis methods. According to matter levels, the frozen-wall is divided into three sub-systems: frozen colloid system, frozen soil system and frozen-wall system. They correspond to different characteristics. The frozen-wall system is a large open system with multi-levels and multi-aspects. The problems of stability of the system and its control are the key problems in the techniques of artificial ground freezing. Based on non-equilibrium thermodynamics and dissipative structure theory methods, the author discusses and reveals the problems of the formation and stability of the frozen-wall system and its thermodynamic nature, and proposes the thermodynamic entropy models of the system. The result is a great satisfaction. 相似文献
63.
Zan Ting-quan 《应用数学和力学(英文版)》1988,9(10):985-992
This series of papers is prepared to develop systematically the complicated dynamical behaviors of nonlinear ecosystem and its internal mechanism. In this paper, we state briefly the increasing importance of ecology, describe and comment on the situations and reasons why ecology theory is behind practice. Then, we point out a procedure which modern ecology research should obey, and discuss the four basic characteristics of ecosystem in detail: level, opening, nonlinear and far from equilibrium. At last, we discuss systematically equilibrium and nonequilibrium, stable and unstable, environmental stochasticity and dynamical stochasticity, and conclude that there exists a bridge between deterministic behaviors and stochastic behaviors, which will result in a new model for ecological prediction.Supported by Youth Fund of Chinese Academy of Science and Youth Fund of Lanzhou University. 相似文献
64.
65.
Das MC Xu H Wang Z Srinivas G Zhou W Yue YF Nesterov VN Qian G Chen B 《Chemical communications (Cambridge, England)》2011,47(42):11715-11717
A doubly interpenetrated semiconducting MOF Zn(4)O(2,6-NDC)(3)(DMF)(1.5)(H(2)O)(0.5)·4DMF·7.5H(2)O (UTSA-38) of a cubic net has been constructed, which exhibits photocatalytic activity for the degradation of methyl orange in aqueous solution. 相似文献
66.
Wang Z Luan D Madhavi S Li CM Lou XW 《Chemical communications (Cambridge, England)》2011,47(28):8061-8063
Polycrystalline α-Fe(2)O(3) nanotubes with thin walls have been synthesized by one-step template-engaged precipitation of Fe(OH)(x) followed by thermal annealing. In virtue of the unique structural features, these α-Fe(2)O(3) nanotubes exhibit superior lithium storage capabilities with exceptional high-rate capacity retention as a potential anode material for lithium-ion batteries. 相似文献
67.
传统DEA模型在数据两分(偏好与规避)的基础上考察决策单元的有效性,在某些场合不再适用,文章根据决策者的偏好将数据分为三类:规避、偏好、中性类,在此基础上构造评价相对有效性的DEA模型.相较而言,基于数据三分法的DEA模型更具一般性,利用该模型,文章考察了中国近年投入产出绩效问题. 相似文献
68.
69.
利用神光Ⅱ装置上搭建的用于激光冲击波实验的温度诊断系统(该系统包括高时空分辨的扫描高温计和谱时分辨的扫描高温计),以强激光加载铝材料冲击温度的测量,获得了铝材料冲击高温辐射发光谱的高时空分辨信号图像,结合灰体辐射理论模型,计算得到了冲击波速度19.06 km/s时铝材料的冲击温度达2.95 eV,该温度与SESAME库中冲击温度接近。研究结果表明采用该测温系统能够有效诊断金属材料的冲击温度,为后续进一步获取金属材料冲击温度数据奠定了基础。 相似文献
70.
Linzhu Zhang Lu Chen Yuzhou Xia Zhiyu Liang Renkun Huang Ruowen Liang Guiyang Yan 《Molecules (Basel, Switzerland)》2022,27(21)
The construction of a multi-component heterostructure for promoting the exciton splitting and charge separation of conjugated polymer semiconductors has attracted increasing attention in view of improving their photocatalytic activity. Here, we integrated Au nanoparticles (NPs) decorated CeO2 (Au–CeO2) with polymeric carbon nitride (PCN) via a modified thermal polymerization method. The combination of the interfacial interaction between PCN and CeO2 via N-O or C-O bonds, with the interior electronic transmission channel built by the decoration of Au NPs at the interface between CeO2 and PCN, endows CeAu–CN with excellent efficiency in the transfer and separation of photo-induced carriers, leading to the enhancement of photochemical activity. The amount-optimized CeAu–CN nanocomposites are capable of producing ca. 80 μmol· H2 per hour under visible light irradiation, which is higher than that of pristine CN, Ce–CN and physical mixed CeAu and PCN systems. In addition, the photocatalytic activity of CeAu–CN remains unchanged for four runs in 4 h. The present work not only provides a sample and feasible strategy to synthesize highly efficient organic polymer composites containing metal-assisted heterojunction photocatalysts, but also opens up a new avenue for the rational design and synthesis of potentially efficient PCN-based materials for efficient hydrogen evolution. 相似文献