Laboratory longitudinal diffusion tests: 1. Dimensionless formulations and validity of simplified solutions

To obtain reliable diffusion parameters for diffusion testing, multiple experiments should not only be cross-checked but the internal consistency of each experiment should also be verified. In the through- and in-diffusion tests with solution reservoirs, test interpretation of different phases often makes use of simplified analytical solutions. This study explores the feasibility of steady, quasi-steady, equilibrium and transient-state analyses using simplified analytical solutions with respect to (i) valid conditions for each analytical solution, (ii) potential error, and (iii) experimental time. For increased generality, a series of numerical analyses are performed using unified dimensionless parameters and the results are all related to dimensionless reservoir volume (DRV) which includes only the sorptive parameter as an unknown. This means the above factors can be investigated on the basis of the sorption properties of the testing material and/or tracer. The main findings are that steady, quasi-steady and equilibrium-state analyses are applicable when the tracer is not highly sorptive. However, quasi-steady and equilibrium-state analyses become inefficient or impractical compared to steady state analysis when the tracer is non-sorbing and material porosity is significantly low. Systematic and comprehensive reformulation of analytical models enables the comparison of experimental times between different test methods. The applicability and potential error of each test interpretation can also be studied. These can be applied in designing, performing, and interpreting diffusion experiments by deducing DRV from the available information for the target material and tracer, combined with the results of this study.     

废锂电池配合-沉淀体系碱浸液中铝的回收

为分离回收废锂电池中的铝,在含铁及含铁锰的两种碱浸液中构建了金属（Me）-OH^--CO₃^2-,Me-OH^--NH₃,Me-OH^--NH₃-CO₃^2-三种配合-沉淀体系,分析了三种体系在不同pH条件下的铝去除率和Al（OH）₃沉淀中的铁及铁锰含量。实验结果表明：含铁碱浸液在pH为8.0~10.0的适宜条件下,Me-OH^--CO₃^2-、Me-OH^--NH₃和Me-OH^--NH₃-CO₃^2-体系的铝去除率分别高达99.4%、99.7%和99.6%,Al（OH）₃沉淀中含少量铁,Me-OH^--NH₃-CO₃^2-体系生成的Al（OH）₃沉淀比Me-OH^--NH₃ 体系的Al（OH）₃沉淀更易分离;含铁锰碱浸液Me-OH^--CO₃^2-、Me-OH^--NH₃和Me-OH^--NH₃-CO₃^2-体系的铝去除率分别高达99.4%,99.7%和99.9%,Al（OH）₃沉淀中几乎不含锰,含有少量铁。     

基于煤矿安全风险成因的国家应对体系研究

基于煤矿安全的重要性,介绍了导致我国煤矿矿难的6大主要风险因素:社会经济发展阶段、煤矿安全生产相关立法情况、能耗结构、煤矿行业人员能力、煤矿技术设备先进程度和监管有效性水平。针对这6个要素,通过问卷调查、深度访谈、案例研究的方式,研究了国家应对煤矿安全风险的体系规划。结果表明:国家在应对煤矿安全风险方面,必须采取5方面的措施,包括制定抑制经济过快增长的宏观政策和鼓励新能源政策、加强立法、吸引煤炭高等院校人才和培训在职人员﹑投资煤炭新技术研究和增加设备投入以及完备有效监管途径。应对体系从宏观、中观和微观的角度提出国家、行业、企业防范煤矿安全风险所要采取的措施,构建了从上而下的提升途径。     

区间数多属性决策在飞机一发失效应急程序方案优选中的应用

针对在飞机一发失效应急程序方案的选择中,很多定量因素难以精确量化的问题,将区间数多属性决策运用到飞机一发失效应急程序方案的优选中,构建了评价指标体系。此评价指标体系应用基于理想解的区间数多属性决策的相对隶属度法来选择最佳方案,该方法通过计算并查找现有方案的相对隶属度最大值来确定最佳方案。最后举例说明如何在实际中使用此方法。     

矿井风流温度预测分析研究

随着煤矿机械化程度不断提高,特别是随着开采深度逐渐增加,矿井热害问题日益突显,高温环境不仅影响生产效率而且严重危害着工作人员的健康。为了更好地降低高温矿井开采时期巷道风流温度,确定合理的巷道布置方案和矿井通风系统,提出矿井巷道风流温度预测方法。以矿井通风和热力学为基础,结合网络解算,对矿井风流温度分布进行研究,总结各种类型巷道风流温度的计算方法,提出多点风流混合温度计算模型。结合具体矿井进行实际预测分析,预测结果中显示风流温度可能超限的巷道,对通风系统进行优化设计。     

基于模糊TOPSIS的道路危险货物运输企业安全评价方法

为了评估道路危险货物运输企业安全性水平,降低危险货物运输风险概率,围绕道路危险货物运输企业安全性评价的重要性,提出一种适用于模糊不确定环境的道路危险货物运输企业安全性评价方法。首先,从人-机-组织综合角度建立道路危险货物运输企业安全性评价指标体系;其次,组合运用模糊决策理论、群体决策和TOPSIS方法提出道路危险货物运输企业安全性评价方法框架;最后以南京市5家道路危险货物运输企业的安全性评价为例进行方法验证。     

新一代复杂电子系统可靠性解决方案探讨

本文通过分析复杂电子系统的设计特点及其对RMS的需求,借鉴国外先进成功经验,针对复杂电子系统各层次产品特点及其对传统RMS技术的挑战,提出复杂电子系统可靠性整体解决方案的思路,以抛砖引玉。     

液相同时脱硫脱硝技术研究

综述了国内外目前开发的液相同时脱硫脱硝技术,包括湿式洗涤并脱硝(WSA-SNOx)工艺、氯酸氧化工艺(Tri NOx-NOxSorb)、湿式络合吸收(Fe-EDTA金属螯合物联合脱硫脱硝)工艺、乳化黄磷法脱硫脱硝工艺、尿素和添加剂液相脱硫脱硝工艺等新方法.分析了各种工艺的特点及存在问题,并对其应用前景进行了预测.     

UV/Fenton光解处理含三唑磷废水的研究

采用类UV／Fenton法对模拟三唑磷废水进行处理。在模拟废水中人工投加H2O2和Fe^3＋试剂能产生类Fenton试剂，类Fenton试剂在光照条件过程中可以产生大量活性羟基．OH，能够很好地氧化降解废水中的有机化合物。本方法可以有效的处理低浓度的含三唑磷的废水，提供三唑磷农药水样的UV／Fenton催化氧化过程的一级动力学方程。     

Increasing the efficiency of solute leaching: impacts of flow interruption with drainage of the “preferential flow paths”

Most soils contain preferential flow paths that can impact on solute mobility. Solutes can move rapidly down the preferential flow paths with high pore-water velocities, but can be held in the less permeable region of the soil matrix with low pore-water velocities, thereby reducing the efficiency of leaching. In this study, we conducted leaching experiments with interruption of the flow and drainage of the main flow paths to assess the efficiency of this type of leaching. We compared our experimental results to a simple analytical model, which predicts the influence of the variations in concentration gradients within a single spherical aggregate (SSA) surrounded by preferential flow paths on leaching. We used large (length: 300 mm, diameter: 216 mm) undisturbed field soil cores from two contrasting soil types. To carry out intermittent leaching experiments, the field soil cores were first saturated with tracer solution (CaBr₂), and background solution (CaCl₂) was applied to mimic a leaching event. The cores were then drained at 25- to 30-cm suction to empty the main flow paths to mimic a dry period during which solutes could redistribute within the undrained region. We also conducted continuous leaching experiments to assess the impact of the dry periods on the efficiency of leaching. The flow interruptions with drainage enhanced leaching by 10–20% for our soils, which was consistent with the model's prediction, given an optimised “equivalent aggregate radius” for each soil. This parameter quantifies the time scales that characterise diffusion within the undrained region of the soil, and allows us to calculate the duration of the leaching events and interruption periods that would lead to more efficient leaching. Application of these methodologies will aid development of strategies for improving management of chemicals in soils, needed in managing salts in soils, in improving fertiliser efficiency, and in reclaiming contaminated soils.