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In the present paper, we define sensitive pairs via Furstenberg families and discuss the relation of three definitions: sensitivity, F -sensitivity and F -sensitive pairs, see Theorem 1. For transitive systems, we give some sufficient conditions to ensure the existence of F -sensitive pairs. In particular, each non-minimal E system (M system, P system) has positive lower density ( Fs , Fr resp.)-sensitive pairs almost everywhere. Moreover, each non-minimal M system is Fts -sensitive. Finally, by some exampl... 相似文献
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最近,Host,Kra和Maass证明了幂零系统的复杂性的上下界可以分别用两个同阶的多项式来表示.一个自然的问题就是这个结论的逆命题是否成立.本文给出一个反例说明其逆命题是不成立的. 相似文献
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给出了?d-作用下保测系统限制敏感性和限制两两敏感性的定义,证明了对于?d-作用下保测系统来说,在度量ρ是μ-正则的情况下,限制两两敏感性比限制敏感性强.同时证明了对于一个保测系统,限制两两敏感意味着正测度熵. 相似文献
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以表面固定Cu2+的改性大尺寸SiO2大孔材料作为载体, 考察了时间、pH和给酶量对漆酶固定化效果的影响, 并对固定化漆酶的活性和稳定性进行了研究。结果表明:5 h时吸附达到平衡, pH为4.5、漆酶与载体比例为5 mg·g-1时固定化效果最好, 酶活回收率可达到100.4%;固定化漆酶的最适pH和最适温度较游离漆酶的均有升高且范围变宽, 固定化后, 漆酶的pH稳定性和热稳定性都得到显著提高;固定化漆酶的Km值略高于游离漆酶的;固定化漆酶具有良好的操作稳定性, 与底物反应反复操作10批次后剩余酶活为72.7%。 相似文献
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在共轭高分子材料的研究中,聚苯一直是人们关注的热点之一[1~4],但聚苯的不溶和不熔性大大限制了其应用前景,因而可溶性聚苯的开发研究成为目前的一种趋势.合成测基带有烷基和烷氧基的聚苯已有报道[5,6],我们曾会成了侧基带有强推电子基团的可溶性聚苯——聚(N... 相似文献
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一种整体式多孔聚合物的制备及其对于痕量元素吸附性能的研究 总被引:1,自引:0,他引:1
利用逐步聚合反应,以二乙烯三胺为固化剂、聚乙二醇作为致孔剂与环氧树脂按照一定比例混合后,在一定的反应温度情况下,制备了一种新型的环氧树脂基整体式多孔聚合物.重点研究了致孔剂的种类、三者的比例以及反应温度等因素对整体式多孔聚合物制备中孔径的影响,并初步研究了此聚合物对痕量离子Au(Ⅲ)、Pt(Ⅳ)、Pd(Ⅳ)的吸附性能. 相似文献
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In the present paper, we define sensitive pairs via Furstenberg families and discuss the relation of three definitions: sensitivity, F -sensitivity and F -sensitive pairs, see Theorem 1. For transitive systems, we give some sufficient conditions to ensure the existence of F -sensitive pairs. In particular, each non-minimal E system (M system, P system) has positive lower density ( Fs , Fr resp.)-sensitive pairs almost everywhere. Moreover, each non-minimal M system is Fts -sensitive. Finally, by some examples we show that: (1) F -sensitivity can not imply the existence of F -sensitive pairs. That means there exists an F -sensitive system, which has no F -sensitive pairs. (2) There is no immediate relation between the existence of sensitive pairs and Li-Yorke chaos, i.e., there exists a system (X, f ) without Li-Yorke scrambled pairs, which has κ B -sensitive pairs almost everywhere. (3) If the system (G, f ) is sensitive, where G is a finite graph, then it has κ B -sensitive pairs almost everywhere. 相似文献
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