带有非线性边界条件的非线性抛物型方程组的爆破速率估计

In this paper, the estimate on blow-up rate of the following nonlinear parabolic system is considered: We will prove that there exist two positive constants such that: where l_1= l_(21)α／α_2 l_(22),r=α_1／α_2＞1,α_1≤α_2＜0.     

Quantitative Studies of Metal Ion Adsorption on a Chemically Modified Carbon Surface: Adsorption of Cd(II) and Hg(II) on Glutathione Modified Carbon

The adsorption behavior of model toxic metal cations namely Cd(II) and Hg(II) on carbon surfaces chemically modified by glutathione was investigated as a function of the concentration of Cd²⁺ and Hg²⁺ ions, time and the amount of modified carbon used. Square wave and linear sweep anodic stripping voltammetry was used to monitor the uptake of Cd(II) and Hg(II) ions respectively. Kinetic and adsorption isotherm studies reveal that both Cd(II) and Hg(II) ions undergo similar large adsorption with the modified glutathione carbon material (Glu‐carbon).     

Optimal decay rates and the selfadjoint property in overdamped systems

We deal with abstract linear strongly damped wave equations. In the so-called overdamped regime we show the occurrence of two interesting phenomena. The first is the existence of an explicit special inner product which makes the problem selfadjoint. The second is an improvement of the decay rate for more regular solutions that will be of an exponential-polynomial type. Furthermore, we prove the optimality of this decay rate.     

Power-Law Behavior in Signal Scattering Process in Vertical Granular Chain with Light Impurities

We investigate the scattering process of impulse in vertical granular chain with light impurities. When the perturbation is weak, the quantities describing the reflection rate exhibit power-law behavior with the impurity depth. The exponent is nearly independent of vi. When the perturbation is very strong, the vertical chain shows similar behavior to that of the horizontal chain, so the exponent is nearly zero. Our numerical investigation begins from the weak perturbation region and extends to the nonlinear region and found a peak of the exponent. The difficulty in extending the numerical investigation to a stronger perturbation region is analyzed.PACS numbers: 45.70.-n, 43.25. y, 46.40.Cd     

Bounded rational expectations and the stability of interest rate policy

The New Keynesian model has recently been subject to two serious criticisms: the model cannot produce plausible inflation and output dynamics following a monetary shock, and the stability of its dynamics suffers from indeterminacy. The procedures that have been proposed to eliminate these two shortcomings fall into two categories: the introduction of some sort of backward price indexation into the standard model and/or other forms of stickiness (like sticky information); and the adoption of some form of policy rule that completely offsets the effects of forward looking dynamics in the optimization process. In this paper we do not eradicate forward looking behavior from the dynamics of the New Keynesian model, neither do we impose some form of backward price indexation. We assume that private economic agents have forward looking behavior and that they do try to optimize with all available information; the only novelty is that they are allowed to make small mistakes near the rational expectations equilibrium, in a fully deterministic setup. These “near rational” or “bounded rational” expectations show that the dynamics of the model with active interest rate rules is much richer than the simple problem of local indeterminacy as is usually found in the literature.     

煤燃烧过程中汞、砷、硒反应机理研究

本文以三种典型煤为对象,测定了煤及灰中汞,砷,硒的浓度,了解了元素的挥发性。对钱家营褐煤进行了不同温度的燃烧实验。测定了在不同温度下燃烧灰中汞,砷,硒的含量变化。将所得实验结果与化学热力平衡分析工具F~*A~*C~*T2.1模拟系统结果相比较。推测了其中可能发生的反应。     

Energy relaxation method for chemical non‐equilibrium flow computations

In this paper, an algorithm for chemical non‐equilibrium hypersonic flow is developed based on the concept of energy relaxation method (ERM). The new system of equations obtained are studied using finite volume method with Harten–Lax–van Leer scheme for contact (HLLC). The original HLLC method is modified here to account for additional species and split energy equations. Higher order spatial accuracy is achieved using MUSCL reconstruction of the flow variables with van Albada limiter. The thermal equilibrium is considered for the analysis and the species data are generated using polynomial correlations. The single temperature model of Dunn and Kang is used for chemical relaxation. The computed results for a flow field over a hemispherical cylinder at Mach number of 16.34 obtained using the present solver are found to be promising and computationally (25%) more efficient. The present solver captures physically correct solution as the entropy conditions are satisfied automatically during the computations. Copyright © 2007 John Wiley & Sons, Ltd.     

Integrated rate expression for the production of glucose equivalent in C4 green plant and the effect of temperature

A temperature-dependent integrated kinetics for the overall process of photosynthesis in green plants is discussed. The C₄ plants are chosen and in these plants, the rate of photosynthesis does not depend on the partial pressure of O₂. Using some basic concepts like chemical equilibrium or steady state approximation, a simplified scheme is developed for both light and dark reactions. The light reaction rate per reaction center (R′ ₁) in thylakoid membrane is related to the rate of exciton transfer between chlorophyll neighbours and an expression is formulated for the light reaction rate R′ ₁. A relation between R′ ₁ and the NADPH formation rate is established. The relation takes care of the survival probability of the membrane. The CO₂ saturation probability in bundle sheath is also taken into consideration. The photochemical efficiency (ϕ) is expressed in terms of these probabilities. The rate of glucose production is given by R _glucose = (8/3)(R′ ₁ v _L )ϕ(T) _g (T) ([G3P]/[P _i]² _leaf)_SS Q _{G3P→glucose} where g is the activity quotient of the involved enzymes, and G3P represent glycealdehyde-3-phosphate in steady state. A Gaussian distribution for temperature-dependence and a sigmoid function for de-activation are incorporated through the quotient g. In general, the probabilities are given by sigmoid curves. The corresponding parameters can be easily determined. The theoretically determined temperature-dependence of photochemical efficiency and glucose production rate agree well with the experimental ones, thereby validating the formalism.     

浅议电视信号的数字化与码率压缩

介绍了电视信号数字的优点、含义和彩色电视信号的编码标准——CCIR601建议，讨论了电视信号常用的码率压缩技术。     

合理开发可再生资源的向量微分模型及其应用

本文首先建立了按年龄分组的可再生资源，各年龄组数量应满足的向量微分模型．然后利用所建模型成功地解决了ＣＭＣＭ９６Ａ题中的问题２．