Periodic solutions for a quasilinear non-autonomous second-order system

In this paper, a quasilinear second-order system with periodic boundary conditions is studied. By the least action principle and classical theorems of variational calculus, existence results of periodic solutions are obtained.     

Calculation of number and free energy of the conformers of linear alkanes with medium and long chains. Implications for catalysis

A method for calculating the number of rotamers of a linear alkane and of the number of rotamers with a given number of gauche conformations along the chain as a function of the total number of atoms in the chain, using general equations, is presented. A graphical method for generating individual rotamers was applied to the homologs up to decane, which has 1134 rotamers. The steric energies calculated by molecular mechanics (MM2 force field) were used as measures of the heat of formation for the coiled conformations relative to the anti conformer for each molecule, whereas the statistical entropy differences were calculated for classes of coiled rotamers grouped by the number of gauche bonds and steric energy. The free energy values calculated from these components show that already at 400 K hexane exists preferentially in conformations containing gauche bonds. For larger chains the free energy advantage for the coiled chains increases very steeply. The implications for the question of reactions of linear alkanes occurring on the surface or inside the channels of small- and medium-pore zeolites are briefly examined.     

On the uniqueness of the foliation of spheres of constant mean curvature in asymptotically flat 3-manifolds

In this note we study constant mean curvature surfaces in asymptotically flat 3-manifolds. We prove that, outside a given compact subset in an asymptotically flat 3-manifold with positive mass, stable spheres of given constant mean curvature are unique. Therefore we are able to conclude that the foliation of stable spheres of constant mean curvature in an asymptotically flat 3-manifold with positive mass outside a given compact subset is unique.

     

Effect of Incident Intensity on Films Growth in Pulsed Laser Deposition

Incident intensity, defined by the amount of particles deposited per pulse, is an important parameter in the film growth process of pulsed laser deposition （PLD）. Different from previous models, we investigate the irreversible and reversible growth processes by using a kinetic Monte Carlo method and find that island density and film morphology strongly depend on pulse intensity. At higher pulse intensities, lots of adatoms instantaneously diffuse on the substrate surface, and then nucleation easily occurs between the moving adatoms resulting in more smaller-size islands. In contrast, at the lower pulse intensities, nucleation event occurs preferentially between the single adatom and existing islands rather than forming new islands, and therefore the average island size becomes larger in this case. Additionally, our results show that substrate temperature plays an important role in film growth. In particular, it can determine the films shape and weaken the effect of pulse intensity on film growth at the lower temperatures by controlling the mobility rate of atoms. Our results can match the related theoretical and experimental results.     

带强迫项变系数组合KdV方程的显式精确解

通过构造两个新的Riccati方程组，推广了Riccati方法，使其具有简洁的形式，丰富和发展了已有的结果，借助Mathematica软件，求出了带强迫项变系数组合KdV方程的一些精确解，包括各种类孤波解、类周期解和变速孤波解. 关键词： Riccati方程组 变系数组合KdV方程 强迫项 类孤波解     

交流源作用下介观RLC电路系统量子态随时间的演化

根据量子不变量理论，同时考虑介观电容器极板间电子波函数的耦合作用和电路的耗散,研究介观RLC电路系统在交流电流源作用下动力学的演化过程，并且得到描述系统量子态随时间的演化算符.进一步的分析结果表明，介观RLC电路系统的波函数将由任意的初态演化到一般的压缩态. 关键词： 介观RLC电路 交变电源 不变量理论 时间演化算符     

火工品可靠性试验数据的综合分析方法

升降法试验数据和固定刺激量下的成败型试验数据,是两种最常见的火工品可靠性试验数据．我们应用Markov链,研究了升降法试验数据下,感度分布参数的极大似然估计的特性．在此基础上,应用Bootstrap方法和Bayes方法,给出了综合分析两种试验数据的方法．最后,将该方法应用于520底火的可靠性鉴定,得出了有益的结论．     

新型材料--光子晶体

半个世纪以来，对半导体技术的深入研究和广泛应用推动了电子工业和信息产业的迅速发展。目前半导体技术正向高速度、高集成化方向发展，但这也不可避免地引发了一系列问题，例如电路中能量损耗过大导致集成片发热，如何进一步将电子器件小型化等。人们由此感到半导体器件的能力已基本达到了极限，转而把目光由电子投向了光子，因为光子有着电子所不具备的优势：速度快，彼此间不存在相互作用，一旦实现用光子替代电子传递信息，     

环境光对PE塑料薄膜近红外激光拉曼光谱的影响

探讨了环境光自然光和室内荧光灯光的存在,对PE透明塑料薄膜的近红外激光拉曼光谱的影响.研究表明不同的环境光,会对近红外拉曼光谱产生不同的明显特征峰.自然光干扰产生的是以倒峰群形式为主,而室内荧光灯光造成的干扰主要以尖锐的脉冲峰形式.虽干扰表现形式不同,但都有严重地影响,在测定时一定要引起重视,不能忽略.建议在进行透明塑料近红外拉曼光谱检测时,须在暗室或暗罩遮光保护中进行,以完全隔离环境光的影响.     

Spectroscopic and Structural Study of the 1：2 Aluminium（Ⅲ） Complex of Quercetin

Complex formation between aluminium and quercetin（Q） in methanol was investigated by means of 27^Al solid-state, 13^C and 1^H NMR and MS（ESI）, UV and IR spectra. Formation of the 1：2 complex was favored in methanol relative to all other solvent and the predominant species observed of Al（Ⅲ） has a 1：2 stoichiometry. The fine structure of 1：2 aluminum complex of quercetin was that the aluminum central atom chelated with two quereetin molecules and two methoxyl groups between two five membered rings, its coordination is six, the chelated site was 3-hydroxy-4-carbonyl.