绿色饲料添加剂的研究与应用

本文对几种新型的绿色饲料添加剂的作用、在畜禽生产中的实际应用及存在的问题进行了综述。     

Modeling nonlinearly transient zero-order bioreduction and transport of Cr(VI) in groundwater

Cr(VI) contamination of soil and groundwater is considered a major environmental concern. Bioreduction of Cr(VI) to Cr(III) can be considered a potentially effective technology in remediating Cr(VI) contaminated sites. Shewanella oneidensis MR-1 (MR-1) is one of the bacteria capable of reducing Cr(VI) to Cr(III) under anaerobic conditions. The kinetics of Cr(VI) reduction by MR-1 is defined by the dual-enzyme kinetic model which is nonlinear, transient, and zero-order. Existing transport models are not designed to simulate such reaction kinetics. The objective of this paper is to present a Petrov–Galerkin finite element model (PGFEM) to simulate transport and bioreduction of Cr(VI), by MR-1, in groundwater. The model developed is unconditionally stable and provides oscillation free accurate results for a wide range of Peclet number (Pn) and Courant number (Cn).     

孤岛工作面支承压力影响下顶板破坏机理研究

为了探讨孤岛工作面支承压力影响下顶板破坏机理,通过采用理论分析,建立薄板力学模型,对孤岛工作面顶板弯矩分布规律进行分析,并结合实验室数值模拟手段对工作面顶板支承压力集中系数及顶板围岩塑性区演变规律进行研究。研究结果表明:在支承压力作用下,随着推进距离的增大,顶板支承压力集中系数呈现增大的趋势;工作面顶板煤壁中部弯矩显著大于煤壁两侧弯矩,该结果合理解释了工作面方向上支架工作阻力不相等的规律;顶板断裂的塑性区演变特征存在时空效应及力学特征,顶板四周所形成的横向“O”型破断与横向“X”型破断,共同构成了顶板破断的横“O-X”破断形式。     

净化生活污水沼气池的工艺及其装置应用研究

本文就城镇生活污水净化沼气池的基本结构，设计要求及工艺特点作了试验研究，提出了单池多级环流式，单池多级上流式和多池多级上流式等前处理模式，使净化装置能因地制宜，实用，有效，便于清淘管理。     

阳离子聚合物絮凝剂的研究

通过筛选合成条件，成功地研制了一种絮凝效果优良的阳离子聚合物絮凝剂，并就聚合物的阳离子度、特性粘度以及ｐＨ值、搅拌时间对絮凝能力的影响进行了较深入的研究，得出结论：在大分子量时，阳离子度２４％左右，体系的絮凝效果最佳；体系ｐＨ一８左右，絮凝剂ＷＦ－１最有效；选用ＷＦ－１与其它无机絮凝剂复配使用，应用效果很好；ＷＦ－１是一种很有效的絮凝剂。     

论我国灾害历史的研究

灾害史的研究是灾害学研究的一个重要领域，本文在列举我国历史灾害资料的基础上，论述了灾害历史研究的必要性。     

Framework for environmental impact analysis—with special reference to India

This article reviews the present status of environmental impact analysis (EIA) with special reference to India. In India, legislation already exists that makes EIA mandatory for every new project proposal. Critically analyzing the shortcomings of the present EIA practices, this article proposes a new framework to conduct an EIA, emphasizing that it should be part of the environmental management of the area or region. Among other things, we suggest the following important points: (1) that a comprehensive database of the region be developed for use for conducting an EIA; (2) that emission standards for the proposed industry be set and the existing standards for old industries be reviewed; (3) that a directory of experts be developed; and (4) that the Department of Environment should take responsibility for conducting EIA studies by forming a study team and an evaluation team for every EIA study with members drawn from the directory of experts.     

有机物污染环境的植物修复研究进展

本文综述了近年来国内外有机物污染环境的植物修复研究进展情况 ,重点介绍了多环芳烃、农药、多硝基芳香化合物等持久性有机污染物以及石油和燃油添加剂污染土壤、水体的植物修复原理与技术。     

Description of sorbing tracers transport in fractured media using the lattice model approach

The transport of contaminants in fractured media is a complex phenomenon with a great environmental impact. It has been described with several models, most of them based on complex partial differential equations, that are difficult to apply when equilibrium and nonequilibrium dynamics are considered in complex boundaries. With the aim of overcoming this limitation, a combination of two lattice Bathnagar, Gross and Krook (BGK) models, derived from the lattice Boltzmann model, is proposed in this paper. The fractured medium is assumed to be a single fissure in a porous rock matrix. The proposed approach permits us to deal with two processes with different length scales: advection-dispersion in the fissure and diffusion within the rock matrix. In addition to the mentioned phenomena, sorption reactions are also considered. The combined model has been tested using the experimental breakthrough curves obtained by Garnier et al. (Garnier, J.M., Crampon, N., Préaux, C., Porel, G., Vreulx, M., 1985. Tra?age par 13C, 2H, I- et uranine dans la nappe de la craie sénonienne en écoulement radial convergent (Béthune, France). J. Hidrol. 78, 379-392.) giving acceptable results. A study on the influence of the lattice BGK models parameters controlling sorption and matrix diffusion on the breakthrough curves shape is included.     

Long-range transport potential of semivolatile organic chemicals in coupled air-water systems

Ongoing deliberations on the regulation of semivolatile organic chemicals require the assessment of chemical transport in atmospheric and marine systems. The characteristic travel distance was proposed as a measure for the transport potential in air and water. However, the existing definition treats the transport processes separately. It is shown that combined transport in coupled air-ocean systems can accelerate the overall transport into remote regions. Concentration ratios in air and water change with distance from sources depending on the initial concentration ratio and on the difference between the transport velocities. A measure is suggested facilitating the chemical screening with respect to transport potentials in such air-ocean systems. A case study for alpha and gamma-hexachlorocyclohexane shows that the suggested measure qualitatively reveals the transport potentials of these chemicals and exemplifies possible concentration patterns.