Infinite horizon H_2/H_\infty optimal control for discrete-time Markov jump systems with (x,u,v)-dependent noise

In this paper, an infinite horizon $H_2/H_\infty $ control problem is addressed for a broad class of discrete-time Markov jump systems with ( $x,u,v$ )-dependent noises. First of all, under the condition of exact detectability, the stochastic Popov–Belevich–Hautus (PBH) criterion is utilized to establish an extended Lyapunov theorem for a generalized Lyapunov equation. Further, a necessary and sufficient condition is presented for the existence of state-feedback $H_2/H_\infty $ optimal controller on the basis of two coupled matrix Riccati equations, which may be solved by a backward iterative algorithm. A numerical example with simulations is supplied to illustrate the proposed theoretical results.     

Selective cleavage of protonated penetratin and its substitutes under low‐energy collision‐induced dissociation condition

An understanding of the dissociation of penetratin is important for improving its metabolic stability and cargo‐delivery efficiency. In this study, we describe the selective cleavage of the K15–K16 amide bond of penetratin under the low‐energy collision‐induced dissociation condition in mass spectrometry. A variety of penetratin substitutes have been studied in which key basic amino acids have been substituted within the sequence. The calculated structure indicates that an α‐helix structure prevents the fragmentation of the central peptide domain and the side chain of lysine is involved in the proton translocation process. Copyright © 2010 John Wiley & Sons, Ltd.     

Clung重对数律成立的一个充分条件

设(X.}是独立随机变量列,EX. = O,supEX} < },n > 1以风}是正的单调趋向无穷大序列,买_1._, R:相似文献   

自由基反应动力学模拟新策略

<正>自由基参与的反应动力学过程,实验上难以探测,理论计算模拟也面临诸多的挑战。最近贵州民族大学龙波教授与美国明尼苏达大学Truhlar课题组合作,巧妙设计了电子结构计算策略,定量准确地模拟了CH_3O自由基和三重态O_2分子的反应途径和动力学,相关结果发表在Journal of the American Chemical Society上~1。作者首先用精确的CCSD(T)-F12电子结构方法,结合不同的基组,优     

Preparation,characterization, and properties of poly(aryl ether sulfone) systems with double‐decker silsesquioxane in the main chains by reactive blending

A series of copoly(aryl ether sulfone)s containing double‐decker‐shaped silsesquioxane (DDSQ) in the main chain was prepared. Toward this end, a novel diphenol polyhedral oligomeric silsesquioxane macromer was synthesized by hydrosilylation between 3,13‐dihydro octaphenyl double‐decker silsesquioxane (denoted dihydro DDSQ) and eugenol. The poly(aryl ether sulfone)s were synthesized from diphenol DDSQ, bisphenol A (BPA), and 4‐fluorophenyl sulfone using a one‐step high‐temperature solution method. By adjusting the ratio of diphenol DDSQ to BPA, copolymers with variable DDSQ content in the main chains were obtained. With increased DDSQ content in the main chain, the glass transition temperature decreased based on differential scanning calorimetry, and anti‐degradation was enhanced based on thermogravimetric analysis. Moreover, the dielectric constant κ of pure polymer (3.19 at 1 MHz) initially increased to 4.04 (DDSQ molar ratio = 10%), and then decreased to 2.68 at 1 MHz (DDSQ molar ratio = 100%). Crystallization behavior, solubility, and surface hydrophobicity were also investigated. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 780–788     

Highly Conducting Organic–Inorganic Hybrid Copper Sulfides CuxC6S6 (x=4 or 5.5): Ligand-Based Oxidation-Induced Chemical and Electronic Structure Modulation

Conductive coordination polymers (CPs) have potential in a wide range of applications because of their inherent structural and functional diversity. Three electrically conductive CPs (Cu_xC₆S₆, x=3, 4 or 5.5) derived from the same organic linker (benzenehexathiol) and metal node (copper(I)) were synthesized and studied. Cu_xC₆S₆ materials are organic–inorganic hybrid copper sulfides comprising a π-π stacking structure and cooper sulfur networks. Charge-transport pathways within the network facilitate conductivity and offer control of the Fermi level through modulation of the oxidation level of the non-innocent redox-active ligand. Two Cu_xC₆S₆ (x=4 or 5.5) CPs display high electrical conductivity and they feature a tunable structural topology and electronic structure. Cu₄C₆S₆ and Cu_5.5C₆S₆ act as degenerate semiconductors. Moreover, Cu_5.5C₆S₆ is a p-type thermoelectric material with a ZT value of 0.12 at 390 K, which is a record-breaking performance for p-type CPs.     

Energy Resonance Crossing Controls the Photoluminescence of Europium Antenna Probes

The energy transfer pathways in lanthanide antenna probes cannot be comprehensively rationalized by the currently available models, and their elucidation remains to be a challenging task. On the basis of quantum-chemical ab initio calculations of representative europium antenna complexes, an innovative energy resonance model is proposed, which is controlled by an overall nonet–quintet intersystem crossing on the basis of spin–orbit coupling among the sublevels of the involved states.     

丙烯酸气相热解机理的理论探讨

用自洽场分子轨道法(半经验AM1法及从头算HF/3-21G法)研究了基态丙烯酸脱羧的反应途径. 计算结果表明, 除前人从理论上已经得到的一步反应途径外, 尚有一个与之竟争的二步反应途径, 且两步反应的总速率大于一步反应的. 计算所得的反应速率常数很小, 与实验结果(丙烯酸在827 K仅有25%左右发生脱羧, 脱水等反应)是一致的. 研究表明, 有较稳定的中间体存在, 有可能在实验中被检测到, 但有待于进一步验证.     

Complete Polarization Conversion Characteristics of Dielectric Grating Composed of Left-Handed Materials

The TE/TM polarization conversion characteristics of dielectric grating composed of left-handed materials for the case of plane wave oblique incidence are carefully investigated by a method which combines the multimode network theory with the rigorous mode matching method. It is indicated that complete polarization conversion between TE and TM modes can be realized using left-handed gratings. This can hardly achieve in the conventional right-handed gratings. Comparisons of polarization conversion properties between right-handed gratings and left-handed gratings are given with physical explanations. This unique merit of left-handed periodic structure is of important significance for accurate design of new millimeter wave TE/TM polarization converters.     

锥头弹丸低速撞击下薄金属靶板的穿透

假定薄金属靶板的变形可分为局部变形和整体变形,在此基础上建立了一个新的分析模型,对固支薄金属靶板的低速穿透进行评估.靶板的局部变形分析通过准静态柱形空穴膨胀理论结合靶板的自由表面效应修正函数,给出了靶板对弹丸的阻力表达式,然后计算出局部变形耗能;整体变形分析采用了Wen-Jones模型的近似准静态方法,通过载荷-位移关系和虚功原理计算整体变形耗能.推出了锥头弹丸穿透金属靶板的耗能公式和弹道极限公式.模型预测结果与实验数据进行了比较,发现二者吻合得较好.