A high-order splitting scheme for the advection-diffusion equation of pollutants

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DO对同步硝化反硝化影响及动力学

研究生物接触氧化法中DO对同步硝化反硝化系统脱氮效率的影响。研究结果表明:在溶解氧(DO)为1.0～3.0mg/L范围内,随着反应器内溶解氧浓度的降低,总脱氮去除率提高,保持较好脱氮率的最佳DO为2mg/L左右,并分析了其原因;同时探讨了DO为2mg/L时的动力学方程。     

On the selection of primary variables in numerical formulation for modeling multiphase flow in porous media

Selecting the proper primary variables is a critical step in efficiently modeling the highly nonlinear problem of multiphase subsurface flow in a heterogeneous porous-fractured media. Current simulation and ground modeling techniques consist of (1) spatial discretization of mass and/or heat conservation equations using finite difference or finite element methods; (2) fully implicit time discretization; (3) solving the nonlinear, discrete algebraic equations using a Newton iterative scheme. Previous modeling efforts indicate that the choice of primary variables for a Newton iteration not only impacts computational performance of a numerical code, but may also determine the feasibility of a numerical modeling study in many field applications. This paper presents an analysis and general recommendations for selecting primary variables in simulating multiphase, subsurface flow for one-active phase (Richards' equation), two-phase (gas and liquid) and three-phase (gas, water and nonaqueous phase liquid or NAPL) conditions. In many cases, a dynamic variable switching or variable substitution scheme may have to be used in order to achieve optimal numerical performance and robustness. The selection of primary variables depends in general on the sensitivity of the system of equations to the variables selected at given phase and flow conditions. We will present a series of numerical tests and large-scale field simulation examples, including modeling one (active)-phase, two-phase and three-phase flow problems in multi-dimensional, porous-fractured subsurface systems.     

Modelling dynamics of managed tropical rainforests—An aggregated approach

The overuse of rainforests in the last century and its consequences necessitate a rethinking of logging policies. To this end models have been developed to simulate rainforest dynamics and to allow optional management strategies to be evaluated. Parameterisation of presently existing models for a certain site needs a lot of work, thus the parameterisation effort is too high to apply the models to a wide range of rainforests. Hence, in this paper we introduce the simplified model FORREG using the knowledge we have gained from a more complex model, FORMIX3-Q.     

阿特拉津降解菌的生长规律及降解特征的实验

应用了从农药厂阿特拉津生产车间污泥中分离出的菌种AT菌，进行了菌种生长曲线的测定，求得AT菌的对数期代时为3．87d，生长速率为0．258d^-1；不同基质浓度的降解实验表明，在农药污染质阿特拉津的低浓度体系中，AT菌降解阿特拉津的反应符合一级动力学模式，属于米氏方程曲线的第一阶段的情形，并拟合出关系式V＝0．064S。     

几种湿式烟气脱硫吸收反应的热力学分析

计算了３种湿式烟气脱硫吸收反应达到平衡态时ＳＯ２的分压力。计算结果显示：对于３种湿式脱硫反应，平衡态ＳＯ２的分压力都随温度的升高而增大。所以从化学热力学角度看反应温度高不利于脱硫。综合考虑脱硫效率、运行费用、是否堵塞等因素，推荐采用双碱法进行烟气脱硫。     

潘谢矿区导水裂隙带发育高度与采厚关系回归分析

根据淮南潘谢矿区最近几年导水裂隙带的实测资料,使用功能强大的数学分析软件Origin对其导水裂隙带与采厚关系进行数学回归分析,并对照现有规范中的关系通式,总结出更适合淮南矿区的预测公式,为以后淮南矿区防水煤柱的留设提供更可靠的理论依据。     

用特征有限无法预测大运河对某市潜水污染的影响

用特征有限元法预测了在井群开采条件下大运河水对某市潜水污染的影响，计算了直到２０２０年的污染物相对浓度的分布．该方法数值弥散和数值振荡较小，有相当的实用价值．     

石家庄市大气主要污染物的统计预报

介绍了石家庄市在大气主要污染物预报统计模式方面的研究，包括统计回归分析的原理，预报选取的因子，主要污染物的回归方程及其相关系数和推广应用情况，通过分析指出了模式存在的不足，并给出了改进方向。     

滑坡滑动面方程多项式拟合

本文讨论了滑坡的形态特征来确定滑动面分析方法，应用数据分析方法，通过多项式对滑动面方程进行拟合，工程实践证明拟合后的滑动面方程能满足工程要求。