The parameter perturbation method on elastic wave equation in inhomogeneous medium

I.IntroductionTheelasticwaveininhomogeneousmediumiscomplicatedbecauseofthediffracting,scattering,andtransmutingofthewavetapes.Exceptforsomesimpleandregularmediummode1s,thesolutionofelasticwavehasnotbeengotyet.Nowadays,theresearchoftheelasticwavescattering…     

Correlation between Conformational Parameters and Rheological Properties of Molten Syndiotactic Polypropylenes

Summary: New rheological results with molten polypropylenes of different degrees of syndiotacticity are presented. The temperature dependence of their dynamic viscoelastic functions is correlated with the characteristic ratio. Relaxation time and Newtonian viscosity values are plotted as a function of molecular weight. The very high values of both rheological parameters found for the most syndiotactic polypropylenes are explained considering the reptation model, which links conformational parameters with the viscoelastic response in the molten state.

Disengagement or reptation time as a function of molecular weight.     

强电流铁电阴极电性能参数与发射结果的关系研究

 在实验结果的基础上,从理论上阐述了材料的电滞回线、介电常数、压电常数等性能对电流发射性能的明显影响,并通过材料的掺杂改性提高材料的性能参数,从而达到了提高发射电流密度的目的。     

1.3μm波长光纤偏振参数自动测试仪

本文介绍一种用于1.3μm波长的光纤偏振参数自动测试仪。它利用光路集成封装和计算机自动控制及信号处理等关键技术,方便、可靠、自动地进行1.3μm光纤及其器件偏振参数的测试,对于消光比为40dB以下的偏振态测量,误差优于0.3dB.     

边坡倾倒变形的形成机制与影响因素分析

本文从边坡倾倒的变形特点出发,分析了倾倒变形的力学机制。在此基础上研究了结构面间距及力学参数对变形的影响。通过含有结构面的岩体的应力,位移以及屈服区的分布特点,讨论了反倾边坡的稳定性问题。     

Emission of Sulphur Dioxide During Thermal Treatment of Fossil Fuels

The dynamics of SO₂ emission during thermooxidation of Estonian oil shale, its semicoke, different samples of coal and their mixtures, as well as the influence of Estonian oil shale ash addition (for modelling the CFBC process) on the dynamics were studied. The experiments were carried out with thermogravimetric equipment under dynamic heating conditions (5 K min^-1) in the atmosphere of dried air, with simultaneous gastitrimetric EGA. It was established that SO₂ emission from the fuels started at 200-320°C. Depending on the form of sulphur (organic, pyritic, sulphate), the emission took place in two or three steps, and continued up to 580-650°C, during which 35-75% of the total sulphur was emitted into the gaseous phase. Regulating the mole ratio of free CaO/S in the mixtures of fuels with oil shale ash addition the emission of SO₂ ceased abruptly at 460-540°C and it was limited to the level of 7-30%. This revised version was published online in August 2006 with corrections to the Cover Date.     

Oxyreactive Thermal Analysis of Dispersed Organic Matter, Kerogen and Carbonization Products A Tool for Investigation of the Heated Rock Masses

This paper presents the results of oxyreactive thermal analyses of organic matter in rocks, heated naturally during diagenetic to metamorphic processes. During the experiments we traced the reactions in the temperature range up to 900°C, it means from the very beginning of diagenetic transformations to the highest real temperatures acting in the Earth's crust as a solid phase. The results showed that TA could be a tool for the reconstruction of thermal regime in natural coal-bearing systems. This revised version was published online in August 2006 with corrections to the Cover Date.     

THEORY AND ALGORITHM OF OPTIMAL CONTROL SOLUTION TO DYNAMIC SYSTEM PARAMETERS IDENTIFICATION(Ⅱ)──STOCHASTIC SYSTEM PARAMETERS IDENTIFICATION AND APPLICATION EXAMPLE

IntroductionInthestudyofactualdynamicsystemanditsparametersidentificationproblem,stochasticinputandstochasticparametersarefrequentlyencountered.Suchstochasticfactorsleadtomanycharacteristicsquitedifferenttodeterndnisticsystem.Therefore,theparametersidentificationofstochasticdynamicsystemhasawidersignificance.Similartodeterministicsystem,stochasticdynamicsystemparametersidentificationproblemcanalsobetransformedintoagroupofstochasticdynamicsystemsparametersidentificationproblemwhichisparameteriz…     

QMC模型的介质相关参数的确定及核物质中的夸克凝聚

通过把QMC模型参数展到σ场的一阶项来引入模型参数的核介质效应,并利用核子袋在介质中的平衡条件自洽地确定展开系数.计算结果表明袋参数及核子半径受介质影响较大,而零点运动参数则保持不变.在此基础上,分析了介质相关的模型参数对核物质状态方程及夸克凝聚的影响.