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This paper investigates the exact and approximate spectrum assignment properties associated with realizable output-feedback pole-placement type controllers for single-input single-output linear time-invariant time-delay systems with commensurate point delays. The controller synthesis problem is discussed through the solvability of a set of coupled diophantine equations of polynomials. An extra complexity is incorporated to the above design to cancel extra unsuitable dynamics being generated when solving the above diophantine equations. Thus, the complete controller tracks any arbitrary prefixed (either finite or delaydependent) closed-loop spectrum. However, if the controller is simplified by deleting the above mentioned extra complexity, then the robust stability and approximated spectrum assignment are still achievable for a certain sufficiently small amount of delayed dynamics. Finally, the approximate spectrum assignment and robust stability problems are revisited under plant disturbances if the nominal controller is maintained. In the current approach, the finite spectrum assignment is only considered as a particular case to the designer‘s choice of a (delay-dependent) arbitrary spectrum assignment objective. 相似文献
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用氨基酸对映体在手性毛细管柱上扮离作实例, 研究了任意多阶程升优化程序的普遍适用性. 按计算结果进行实验所得的实际色谱图证明, 优化程序的应用将有助于在保证分离度的前提下, 大大缩短分析时间.提出了一种可以大体反映程序升温下复杂样品各组分在柱内运动过程的轨迹图(x-t图).轨迹图上所显示的每一组分在到达行程终点的时间的准确性得到了色谱实验的验证, 从而为探讨物质在各种条件下的柱内运动状,况特别是为多维色谱的深入研究提供了可能性. 相似文献
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INVESTIGATION OF STRUCTURE AND PROPERTIES FOR POLYMER SYSTEMS BASED ON DYNAMIC RHEOLOGICAL APPROACHES 总被引:2,自引:0,他引:2
MinZuo QiangZheng 《高分子科学》2005,(4):341-354
The dynamic theological measurements have been a preferred approach to the characterization of the structure and properties for multi-component or multi-phase polymer systems, due to its sensitive response to changes of structure for these heterogeneous polymers. In the present article, recent progresses in the studies on dynamic theology for heterogeneous polymer systems including polymeric composites filled with inorganic particles, thermo-oxidized polyolefins, phaseseparated polymeric blends and functional polymers with the scaling and percolation behavior are reviewed, mainly depending on the results by the authors‘ group. By means of theological measurements, not only some new fingerprints responsible for the evolution of morphology and structure concerning these polymer systems are obtained, the corresponding results are also significant for the design and preparation of novel polymer-based composites and functional materials. 相似文献
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Mo-Co系加氢精制催化剂中TiO~2-Al~2O~3载体效应的PASCA研究 总被引:4,自引:0,他引:4
本文采用PASCA(化学分析正电子湮没谱)技术, 系统地研究了MoO~3/γ-Al~2O~3,CoO/γ-Al~2O~3, MoO~3/TiO~2-Al~2O~3, CoO/TiO~2-Al~2O~3等体系中活性组分的表面分散状态和化学状态及其变化规律, 揭示了用TiO~2改性Al~2O~3对Mo-Co系加氢精制催化剂所产生的载体效应的作用机理。Al~2O~3中引入TiO~2使得载体与MoO~3间的相互作用大大减弱, 导致分散态MoO~3易于还原和硫化。助剂CoO与TiO~2-Al~2O~3载体间存在极为显著的电子相互作用, 对于改善Co在活性相中的化学状态, 提高活性中心的内在活性具有重要的作用。PASCA研究的另一个重要结果是, 由于载体表面的不均匀性,使得上述负载型催化剂中氧化物活性组分的表面状态十分复杂, 存在与载体相互作用强弱程度不同的多类特征区, 这些特征区与内在活性不同的催化中心相关联. 通过TiO~2改性Al~2O~3载体, 有效地调节载体表面性质, 改变活性组分表面物种的分布及化学状态。 相似文献
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Bruno Preziosi 《General Relativity and Gravitation》1999,31(2):157-163
It is proved that in experiments on or near theEarth, no anisotropy in the one-way velocity of lightmay be detected. The very accurate experiments whichhave been performed to detect such an effect are to be considered significant tests of bothspecial relativity and the equivalenceprinciple. 相似文献
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Lior M. Burko 《General Relativity and Gravitation》1997,29(2):259-262
We critically examine the Roberts homothetic solution for the spherically symmetric Einstein-scalar field equations in double null coordinates, and show that the Roberts solution indeed solves the field equations only for one non-trivial case. We generalize this solution and discuss its relations with other known exact solutions. 相似文献