动态广义球对称含荷黑洞的统计熵

利用改进了的brickwall膜模型,计算了动态广义球对称含荷黑洞的熵,研究结果表明,对于动态黑洞,将黑洞熵表示为与视界面积成正比时,则比例系数总与动态黑洞的视界速度有关 关键词： 广义球对称黑洞 黑洞熵 brick-wall膜模型 WKB近似     

基于三维矩阵重构争论有向图的域间路由振荡检测算法

边界网关协议(Border G atew ay P rotoco l,BGP)是当前In ternet域间路由协议的事实标准,基于策略的路由选择过程使它不再是严格意义上的距离矢量协议,也不再具有距离矢量协议的收敛性.V aradhan指出,自治系统各自为政的策略配置方式会导致全局策略冲突,引起永久性的路由振荡.针对该问题,G riffin利用稳定路径问题(S tab le Path P rob lem,SPP)模型形式化的抽象出BGP协议行为,并以此为基础提出了一种分布式的策略冲突检测算法,尽管该算法完全避免了传统方法的缺陷,但仍然存在泄漏策略信息和对BGP协议改动太大以及浪费网络资源的问题.本文提出了一种基于安全多方计算的检测路由策略冲突的方法,用于在怀疑BGP路由发生振荡时,动态的检测系统中是否存在策略冲突.该方法采纳了G riffin的理论基础,同时由于巧妙的运用了安全多方计算协议,可以完全解决G riffin算法的问题,具有很好的实用性.     

Volterra积分方程和泛函微分方程的振动性

本文建立了Ｖｏｌｔｅｒａ积分方程和一阶泛函微分方程解的振动准则．     

The interface of the Ising model and the Brownian sheet

We study the limit theorem related to the interface of the three-dimensional Ising model. Dobrushin proved that the interface does not fluctuate and becomes rigid for sufficiently large. We define the random fieldX ^L (t, s), 0t, s1, on the interface, and prove that X^L(t, s) converges to the Brownian sheet as L for sufficiently large, whereL denotes the size of the system. This result does not mean that the interface itself converges to the Brownian sheet.     

Momentum transfer in an agitated vessel with off-centred impellers

Momentum transfer was investigated in an unbaffled agitated vessel of inner diameter 0.3 m equipped with different off-centred impellers. The distribution of the shear rate on the tank wall as a function of the impeller type and Reynolds number was studied in the turbulent regime of the Newtonian liquid flow. The dependences of the averaged dimensionless shear rate, friction coefficient, and dissipated energy on the Reynolds number and eccentricity ratio were approximated using four-parameter equations. Presented at the 33rd International Conference of the Slovak Society of Chemical Engineering, Tatranské Matliare, 22–26 May 2006.     

Mercerization of primary wall cellulose and its implication for the conversion of cellulose I→cellulose II

The mercerization of homogenized primary wall cellulose extracted fromsugar beet pulp was investigated by transmission electron microscopy (TEM),X-ray diffraction together with ¹³C CP-MAS NMR, and FT-IR spectroscopy.For samples resulting from acid extraction, mercerization began at 9% NaOH, whereasfor samples purified by alkaline treatment, the mercerization started at 10%NaOH. The change in morphology when going from cellulose I to cellulose II wasspectacular, as all the microfibrillar cellulose morphology disappeared duringthe treatment. This change in morphology was very drastic as soon as the NaOHconcentrations were increased beyond 8 and 9% for the acid and alkalinepreparedsamples, respectively. On the other hand, the conversion was found to be moreprogressive in terms of increasing NaOH concentration when the transformationwas analyzed by X-ray diffraction or spectroscopy. Our observations of themercerization of isolated cellulose microfibrils are consistent with theconceptof cellulose microfibrils made of parallel chains in cellulose I and crystalsofcellulose II consisting of antiparallel chains.     

醛的自氧化振荡反应

1983年 Jensen 与 Roelofs 等报道了苯甲醛自氧化反应中出现的化学振荡现象。我们还观察到苯甲醛、取代苯甲醛和许多脂肪醛的自氧化振荡反应,实验方法与文献[3]相似。反应在具有电磁搅拌的恒温反应器中进行,以醋酸水溶液(冰醋酸与水的体积比为9∶1)和     

Laser-induced fluorescence microscopic system using an optical parametric oscillator for tunable detection in microchip analysis

A laser-induced fluorescence microscopic system based on optical parametric oscillation has been constructed as a tunable detector for microchip analysis. The detection limit of sulforhodamine B (Ex. 520 nm, Em. 570 nm) was 0.2 mol, which was approximately eight orders of magnitude better than with a conventional fluorophotometer. The system was applied to the determination of fluorescence-labeled DNA (Ex. 494 nm, Em. 519 nm) in a microchannel and the detection limit reached a single molecule. These results showed the feasibility of this system as a highly sensitive and tunable fluorescence detector for microchip analysis.     

Stochastic phase lockings in a relaxation oscillator forced by a periodic input with additive noise: A first-passage-time approach

Noise effects on phase lockings in a system consisting of a piecewise-linear van der Pol relaxation oscillator driven by a periodic input are studied. The problem of finding the period of the oscillator is reduced to the first-passage-time problem of the Ornstein-Uhlenbeck process with time-varying boundary. The probability density functions of the first-passage time are used to define the operator which governs a transition of an input phase density after one cycle of the oscillator. Phase lockings in a stochastic sense are investigated on the basis of the density evolution by the operator.