Flatness,plateau limit and limit length of single-plateau functions

In this paper we consider iteration of single-plateau functions, an important class of continuous functions with infinitely many forts, and investigate changes of number and length of plateaux under iteration.We use the indices flatness, plateau limit and limit length to formulate those changes. Furthermore, we compute the flatness, plateau limit and limit length for all the nine types of single-plateau functions.     

最小偏差分析法在经济周期分析中的应用

利用最小偏差分析法,分析了我国GDP增长率的周期性特征,并对我国今后几年的GDP增长率进行了预测.分析的结果是:从1953—2006年,我国GDP增长率存在着7年左右的小周期,15年左右的中周期,19年左右的中长周期和28年左右的大周期,而且随着时间的推移,经济周期的波动幅度逐渐趋小,反映出经济增长的稳定性增强.预测的结果是:今后几年(2年或更长一段时间)我国GDP增长率应该保持在10%左右,波动的区间为[9%,11%].     

Experimental study on interaction and kinetic characteristics during combustion of blended coals

The combustion behaviors and kinetic parameters of three parent coals (A1, A2, and A3) and their blends (A1/A2 and A2/A3) have been evaluated under oxidizing atmosphere (O₂ and N₂ mixtures), using a non-isothermal thermo-gravimetric analyzer. The aim of this study is to investigate the interaction between the blended components during the process of co-combustion, and the effects of blending ratio and oxygen concentration (10, 15, and 21%) on combustion performance of blended coals. When high reactivity and low reactivity coals are co-combusted, double peaks are observed in the DTG curves, and significant interaction occurs in the temperature range between the two peaks (T _p1 and T _p2). The activation energies obtained by Coats–Redfern method indicate that the activation energies of blended coals are lower than that of parent coals. The combustibility index S is used to evaluate the combustion performance of blended coals, and the results show the non-additive effects of the combustion characteristics of blended coals. The increased oxygen concentration results in a significant improvement of combustion performance of blended coals. In addition, as the blending ratio of high reactivity coal is increased, the oxygen can greatly enhance the combustion stability of blended coals.     

Blow-up for 3-D compressible isentropic Navier-Stokes-Poisson equations

Czechoslovak Mathematical Journal - We study compressible isentropic Navier-Stokes-Poisson equations in ?3. With some appropriate assumptions on the density, velocity and potential, we show...     

Asymptotical stability for complex dynamical networks via link dynamics

From the perspective of large-scale system, a complex dynamical network can be regarded as the interconnected system with the node subsystem and link subsystem, which implies that the node subsystem and the link subsystem are the two main bodies of dynamical behaviors of network. Therefore, the whole stability of network is influenced by not only the dynamics of node subsystem but also the dynamics of link subsystem. According to the above view, the wholly asymptotical stability (WAS) is defined in this paper for the complex dynamical network with the model of differential equations. The WAS is used to describe the node subsystem achieves asymptotical stability when link subsystem achieves also the asymptotic stability in Lyapunov sense. For the WAS of the complex dynamical network, the corresponding criteria are derived by checking whether certain matrices are Hurwitz. The analysis results show that even if the isolated nodes are not asymptotically stable in Lyapunov sense, employing the dynamics of link can also force the node subsystem to achieve the asymptotical stability. Finally, the simulation examples show the validity of methods in this paper.     

Electrophoresis of Bottle‐Brush Polyelectrolytes in an Attractive Nanochannel

A molecular dynamics study of the electrophoresis of bottle‐brush polyelectrolytes (BPEs) through nanochannels is reported. The BPE molecules consist of a neutral backbone with charged side chains. For strong attractive interactions between the BPE and the wall, the BPE is being trapped on the channel surface. A stretching–shrinking migration of the BPE in a channel of radius 6σ is observed at relatively strong electric fields. The stretching–shrinking transition is periodic for intermediate electric fields but not for stronger electric fields. The BPE also shows a transverse migration toward the wall at weak electric fields, while toward the center with further enhancing the electric field. For a channel with larger radius 12σ, the BPE does not migrate in the stretching–shrinking manner.

     

线性二阶锥规划的一个光滑化方法及其收敛性

首先讨论了用Chen-Harker-Kanzow-Smale光滑函数刻画线性二阶锥规划的中心路径条件;基于此,提出了求解线性二阶锥规划的一个光滑化算法,然后分析了该算法的全局及其局部二次收敛性质.     

权回归模型中最小二乘估计的相对效率

对于线性加权回归模型，本文得到了未知参数的最小二乘估计相对于最佳线性无偏估计的四种相对效率的下界，并建立了相对效率与广义相关系数的联系。     

Effects of minerals containing sodium,calcium, and iron on oxy-fuel combustion reactivity and kinetics of Zhundong coal via synthetic coal

Journal of Thermal Analysis and Calorimetry - The greatly high contents of alkali and alkali earth metals in Zhundong coal have a negative impact on the combustion and utilization of the coal,...