Exponential stability of impulsive nonlinear stochastic differential equations with mixed delays

This paper is concerned with the problem of exponential stability for a class of impulsive nonlinear stochastic differential equations with mixed time delays. By applying the Lyapunov–Krasovskii functional, Dynkin formula and Razumikhin technique with a stochastic version as well as the linear matrix inequalities (LMIs) technique, some novel sufficient conditions are derived to ensure the exponential stability of the trivial solution in the mean square. The obtained results generalize and improve some recent results. In particular, our results are expressed in terms of LMIs, and thus they are more easily verified and applied in practice. Finally, a numerical example and its simulation are given to illustrate the theoretical results.     

Event-triggered optimal control for nonlinear stochastic systems via adaptive dynamic programming

Nonlinear Dynamics - For nonlinear Itô-type stochastic systems, the problem of event-triggered optimal control (ETOC) is studied in this paper, and the adaptive dynamic programming (ADP)...     

The cross sections and their temperature dependence of collisional energy transfer from high vibrationally excited ethylene molecules to electronic ground state Rubidium atoms

The cross sections and their temperature dependence of collisional energy transfer from the high vibrationally excited C_2H_4 to the electronic ground sate of Rb (V-E) have been studied by the method of IR laser pump combined with fluorescence probe. The fluorescence of rudidium atoms due to V-E energy transfer was detected. The measured rate constants of this V-E energy transfer is about 10~(-10)cm~2molec~(-1)s~(-1) and the corresponding cross section varies from 60 (?)~2 to 90 (?)~2. The cross sections decrease with increasing temperature over the temperature range of 393-683 K.     

具分布时滞和阻尼项的偶阶半线性中立型微分方程的振动性

研究一类具分布时滞和阻尼项的偶阶半线性中立型微分方程解的振动性质,利用广义Riccati变换和积分平均技巧得到方程一切解均为振动的若干新的振动准则,推广、改进和统一了新近文献中的某些结果.     

Production of Bio-hydrogen Using Bio-oil as a Potential Biomass-derived Renewable Feedstock

The bio-oil derived from pyrolysis of straw can be selectively converted into high-purity hydrogen by coupling three steps:(i)steam refonning(SR)of di tierent bio-oils,(ii)water-gas shift(WGS),and(iii)the removal of CO2.the catalytic SR reaction over the NiLaTiAl catalyst,coupled with a low-temperature WGS reaction with the CuZnAl catalyst,promoted the conversion of various oxygen-contaming organic compounds in the bio-oil into hydrogen and carbon dioxide.Under the optimized condition,light bio-oil achieved the highest conversion(99.8%,molar fraction),with a high hydrogen yield of 16.4%(mass traction)and a H2 purity of 99.94%(volume fraction).The carbon deposition on the NiLaTiAl catalyst was the main factor caused catalyst deactivation.Production of hydrogen from different bio-oil model compounds was also investigated in detail.     

激光引发DNA及多聚核苷酸与SO4.-作用的闪光光谱研究

运用２４８ｎｍ激光光解瞬态吸收光谱研究了ＳＯ４·－与ＤＮＡ及其核苷酸和多聚核苷酸ｐｏｌｙ［Ｇ］、ｐｏｌｙ［Ａ］和ｐｏｌｙ［Ｃ］的相互作用,观察了各体系的作用过程,结果表明,ｐｏｌｙ［Ｇ］、ｐｏｌｙ［Ａ］与ＳＯ４·－发生单电子氧化反应生成嘌呤端基自由基;ｄＣＭＰ与ＳＯ４·－单电子氧化生成阳离子自由基,随后与水反应生成５－羟基－６Ｃ自由基;而ｐｏｌｙ［Ｃ］,ＳＯ４·－先在碱基上加成,生成的加成自由基再从核糖上抽氢生成Ｃ２’－糖自由基;ＤＮＡ与ＳＯ４·－作用生成的主要瞬态产物是鸟嘌呤端基自由基。     

酪氨酸光电离过程的激光闪光光谱研究:pH效应

运用２４８ｎｍ激光闪光光解瞬态吸收光谱研究了不同ｐＨ值水溶液中酪氨酸光解过程,结果表明,溶液ｐＨ值影响酪氨酸的光电离过程;ｐＨ值增大,通过单光子途径的分子增多,而通过双光子途径的分子减少,反之则反。进一步阐明,酪氨酸光电离的ｐＨ效应源于其酚羟基的电离。     

含贵金属的BaZrO3 储存NOx 催化剂结构及性能研究

A series of perovskite-type BaZrO3 catalysts are prepared by the sol-gel method. Their NOx storage capacity（NSC）and the resistance of SO2 poison are measured. XRD,XPS and FT-IR techniques are also used to characterize their structures and the influence of the structures on performance. The results indicate that,after calcinations at 750 and 900 ℃,the Ba and Zr species mainly exist in the form of perovskite BaZrO3 phase,and the BaCO3 and ZrO2 phases also exist. The presence of bulk nitrate is shown by XRD and FT-IR after BaZrO3 absorbing NOx . The Rh/BaZrO3 is prepared by doping 0.5%Rh on the BaZrO3 with the impregnation method. It is found that the Rh mainly deposits on the surface of catalyst. However,the noble metals 0.5% Rh or Pt well disperse on the surface of the sample after the BaZrO3 is mixed with γ-Al2O3 in equal weight proportion. The structure of perovskite BaZrO3 may be partly broken after doping Rh or Pt,because of the reduction by hydrogen in the process of preparing samples,and then some ZrO2 is enriched on the surface. The BaZrO3 catalysts possess high NSC and high resistance ability of SO2 poison. The NSC of Rh/BaZrO3 decreases compared to that of BaZrO3 . However,the NSC of the samples Pt/BaZrO3/γ-Al2O3 and Rh/BaZrO3/γ-Al2O3 increases by 78% and 15% respectively. It is noticed that the NSC enhances for all the samples containing noble metal Pt or Rh duing the 0.01%SO2 mixed with the NO and O2 . It implies that the NO oxidation is improved by SO2 .     

基于可拓层次分析法的测试性分配方法研究

针对传统层次分析(APH)方法在进行测试性分配时没有考虑人判断的模糊性,以及在构造判断矩阵时需要进行一致性检验这两个问题,建立了测试性分配层次结构模型,采用可拓层次分析法对测试性指标进行分配,将符合一致性要求的判断矩阵权重向量的方法有机地融合到可拓层次分析法中;最后结合实例对本文进行应用研究,求得了合适的分配指标,应用结果验证了此方法的可行性。     

基于多源信息加权融合的研制阶段测试性评估方法

装备在研制阶段通常缺乏有效的试验和使用数据,其测试性水平往往难以评估,针对上述问题,提出基于多源信息加权融合的研制阶段测试性评估方法;方法综合考虑了装备研制阶段可利用的仿真信息、专家经验信息以及类似装备的历史信息,构建了以3类信息为基础的装备测试性指标值密度分布函数,同时依据可信度原则确定了3类信息的融合权重;在此基础上,利用证据折扣组合方法评估装备当前的测试性水平;最后,通过案例应用证明了该方法的有效性。