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91.
基于稳定性理论,采用间歇反馈控制研究了四维连续超混沌Rssler和LC振子系统.通过选择恰当的控制周期Ts、自治周期Ta以及反馈系数k来设计控制器.数值计算表明:所设计的控制器使系统经过大约8到35个时间单位达到了稳定点,两个系统之间经过大约15到50个时间单位实现了全局同步.通过求解系统Jacobi矩阵的特征值来确定Ts与Ta的关系,获得间歇控制下控制器稳定的条件.数值计算结果与理论分析一致.
关键词:
超混沌
同步
Jacobi矩阵
稳定性 相似文献
92.
Sufficient conditions are obtained that guarantee the existence of at least two positive solutions for the equation (g(u′(t)))′+a(t)f(u)=0 subject to boundary conditions, by a simple application of a new fixed-point theorem due to Avery and Henderson. 相似文献
93.
94.
本文研究了马氏环境中的马氏链,利用马氏双链的性质,得到了马氏环境中的马氏链回返于小柱集上的概率的若干估计式. 相似文献
95.
Wen -Han Lin Ren -Sheng Xu Ru -Ji Wang Thomas C. W. Mak 《Journal of chemical crystallography》1991,21(2):189-194
A newstemona alkaloid, tuberostemonone (C22H31NO6), has been isolated from the roots ofstemona tuberosa Lour, and its molecular structure determined by MS, IR, NMR spectra and X-ray crystallography (R=0.046 for 1746 observed Mo-K data). Besides retaining the characteristicstemona skeleton, which is composed of an-methyl--lactone and anN-methylene azepine ring linked at the -position of this lactone, the tuberostemonone molecule possesses a nine-membered azacycle which is hitherto not found in other knownstemona alkaloids.On leave from Central Laboratory, Nankai University, Tianjin, China. 相似文献
96.
97.
This paper presents a new chiral separation technology: two-phase (O/W) recognition chiral extraction. Distribution behavior
of α-cyclohexyl-mandelic acid enantiomers was studied in the extraction system with D(L)-isobutyl tartrate in 1,2-dichloroethane organic phase and β-CD derivatives in aqueous phase, and the influence of the kind and concentration of extractant and pH on extraction performance
was investigated. The experimental results indicate that two-phase (O/W) recognition chiral extraction is of strong chiral
separation ability. HP-β-CD, HE-β-CD and Me-β-CD have higher recognition ability for S-CHMA than that for R-CHMA, among which HP-β-CD has the strongest ability; whereas, D-isobutyl tartrate has reversed recognition ability for them. In the extraction system containing HP-β-CD and D-isobutyl tartrate, e.e.% of S-CHMA in aqueous phase reached 27.6% by one stage extraction, and the distribution ratio for R-CHMA(k
R
) and for S-CHMA(k
s
) and separation factor (α) are 2.44, 0.89 and 2.49, respectively. Meanwhile, pH and concentration of extractant have great
effects on chiral separation ability. Two-phase (O/W) recognition chiral extraction has great significance for preparative
separation of racemic compounds.
Supported by the National Natural Science Foundation of China (Grant No. 20776038) 相似文献
98.
99.
Biomarkers can be used for the screening and clinical diagnosis of cancer, and peptidomics approach has been proven successful in the research of biomarkers. To develop better peptidomic technologies for fast, accurate, and reliable detection of peptides biomarkers for lung cancer, we have improved the procedures of blood collection to minimize the degradation of the blood proteins and optimize the extraction of peptidome peptides from plasma samples based on acetonitrile precipitation associated with size exclusion chromatography (SEC). Studies show that squamous cell carcinomas are found to express CAGE1, SPAT9 and TEX28 genes at significantly higher rates, and the results suggest that as tumors progress, the level of CAGE1, SPAT9 and TEX28 genes are likely to increase and lead to immunization. This suggests a potentially important therapeutic method for cancer testis-based cancer vaccines. 相似文献
100.