Synchronization of complex dynamical networks with time delays

In the present paper, two kinds of dynamical complex networks are considered. The first is that elements of every node have different time delays but all nodes in such networks have the same time-delay vector. The second is that different nodes have different time-delay vectors, and the elements of each node also have different time delays. Corresponding synchronization theorems are established. Numerical examples show the efficiency of the derived theorems.     

Development of aryl-containing dipyrrolyldiketone difluoroboron complexes (BONEPYs): Tune the hydrogen bond o–CH···F for fluoride recognition

Dipyrrolyldiketone difluoroboron complexes (BONEPYs) were synthesized by condensation of the corresponding pyrroles and malonyl chloride followed by treatment with BF₃·OEt₂. The aryl-substituted pyrrole is introduced to form a cyclic system in order to investigate anion binding studies. In BONEPYs 1–3 the o-H of the aryl group forms hydrogen bonding with F⁻ to give a more table complex. In contrast, the intramolecular hydrogen-bonded BONEPY endo-4 is more stable than its exo isomer. While adding F⁻, the hydrogen bonds must be broken first to give 4·(3)F⁻. Owing to the electron-rich group (-OMe), the o-H of the phenyl group can hardly interact with F⁻ via hydrogen bonding to give the less stable complex 4·(5)F⁻. The energy differences between the different conformations were calculated using DFT methods, which is consistent to the experimental observations.     

煤炭码头船货匹配下泊位动态分配多目标优化模型及算法

本文针对输出型煤炭码头船货匹配下泊位动态分配问题,构建了堆场-取装线-泊位-船舶联合分配优化数学模型,并设计了采用仿真推演策略解码的遗传算法求解。首先,综合考虑船舶、泊位、堆场、取装线、煤种、航道开放时间和装船作业规则等要素,以船舶在港时间最短和作业效率最大为目标建立了相应的多约束多目标优化模型。然后,综合多目标优化、遗传算法以及仿真推演技术,设计了相应的遗传算法求解,包括:组合式编码、采用仿真推演策略的解码方法,追加了具有合法性检查的染色体生成算法,设计了采用多种策略的遗传操作等。最后实例表明,本算法的执行效率高而且优化效果好。     

The high-temperature heat capacity of LnPO4 (Ln = La,Ce, Gd) by drop calorimetry

The high-temperature heat capacity of three lanthanide orthophosphates of monazite structure have been measured in the temperature range (450 to 1570) K. The data have been analysed in terms of a lattice term, represented by the 4f⁰ and 4f⁷ compounds LaPO₄ and GdPO₄, and an electronic term for CePO₄. The calculated excess heat capacity thus obtained is in reasonable agreement with that calculated from the crystal field energies.     

Angle-resolved time-of-flight spectra of neutral particles desorbed from laser irradiated CdS

Angle-resolved time-of-flight spectra of neutral particles desorbed from laser irradiated CdS have been investigated with a pulse mass counting method. Three quantities to characterize the desorption dynamics — the desorption flux, the mean kinetic energy and the speed ratio — depend remarkably on the incident laser power and the ejection polar angle θ. The desorption flux is strongly peaked forward deviating from the cosine distribution. For low laser power, the desorbing S₂ follows the same Maxwellian velocity distribution over the polar angles below 50°. For high laser power, the Maxwell distribution is limited to a narrow cone around the polar axis and with increasing polar angle the spectra of the velocity distribution become broader than the simulated Maxwellian one. With increasing laser power the mean kinetic energy increases for gq < 40°, while for θ > 40° it decreases abnormally. For these apparent breakdowns of the Maxwell law and Knudsen law, the dynamic behaviour of desorbing particles obeys a non-equilibrium thermal mechanism, which may involve a solid-gas phase transformation.     

Parallel nested dissection for path algebra computations

This paper extends the authors' parallel nested dissection algorithm of [13] originally devised for solving sparse linear systems. We present a class of new applications of the nested dissection method, this time to path algebra computations (in both cases of single source and all pair paths), where the path algebra problem is defined by a symmetric matrix A whose associated graph G with n vertices is planar. We substantially improve the known algorithms for path algebra problems of that general class; this has further applications to maximum flow and minimum cut problems in an undirected planar network and to the feasibility testing of a multicommodity flow in a planar network.     

A simple technique in Markovian control with applications to resource allocation in communication networks

The purpose of this note is to demonstrate that for semi-Markov decision problems with exponentially distributed transition times considerable computational improvements on the value-iteration algorithm can be obtained. This can be achieved by the simple trick of introducing fictitious decision epochs so that sparse transition matrices are created. Applications to optimal sharing of resources in communication networks are given.     

Photoreaction of 9-dicyanomethylene-1,2,3,4-tetrahydro-1,4-methanonaphthalene: the 1,3-carbon migrations and the ethylene extrusion to dicyanoisobenzofulvene

Irradiation of 9-dicyanomethylene-1,2,3,4-tetrahydro-1,4-methanonaphthalene gave 3,3-dicyano-1,2,3,8b-tetrahydrocyclopent [a] indene and 2-dicyanomethylene-2H-indene.     

PdCl2(MeCN)2-catalyzed carbonylation of diethylamine with carbon dioxide: Selective synthesis of tetraethylurea and diethylformamide

The reaction of diethylamine with carbon dioxide (CO₂) with PdCl₂(MeCN)₂ as a catalyst gives tetraethylurea(1) or diethylformamide(2) selectively under mild reaction conditions by employing the PPh₃/CCl₄/MeCN and the HCOONa/methyl cellosolve systems, respectively.     

非相对论弱相互作用玻色气体的有效场理论处理

采用有效场理论研究了非相对论弱相互作用玻色-爱因斯坦凝聚量子气体的一般性质.在分析了系统的不可重整化性质后,从有效拉氏量出发,计算了最低阶环路修正下拉氏量参量的运动耦合常数(running coupling constant)的形式,并且得到了相应的微分方程.研究结果表明,不同于相对论玻色气体的有效理论,对非相对论弱相互作用的玻色气体,可以移除该有效理论中的内禀能量尺度,即可令该有效理论的内禀能量尺度取无穷大值.所得的分析结果将有助于对玻色-爱因斯坦凝聚的临界性质和行为的深入研究.