品位指标优化中损失率与贫化率数学模型

本文中两个数学模型的建立使损失率与贫化率指标由以往的静态参数变为动态参数,其随品位指标方案的不同而变化,提高了品位指标优化的精度。另外这两个模型也是在计算机上建立完整的矿床经济模型不可缺少的部分,对地质经济工作计算机化,提高地质经济工作的速度和精度都有十分重要的意义。     

绿色交通理念下的城市平面交叉口慢行一体化规划方法研究

慢行交通是城市规划提倡的低碳、环保的绿色交通出行方式,可实现居民的短距离出行和接驳公共交通。城市平面交叉口是城市道路交通的关键节点,本文从地面慢行系统一体化、行人过街安全岛规划、公交站台一体化等方面入手,提出城市平面交叉口慢行一体化的规划,以满足交叉口慢行交通的通行需求,实现机非分离,保障慢行者的出行安全。     

Evaluation of hydrocyclone models for practical applications

Hydrocyclone is an important industrial solids–liquid separation equipment. Although widely used nowadays, the selection and design of hydrocyclones are still empirical and experience based. Although quite a few hydrocyclone models had been developed over the years, the validity of these models for practical applications was still not clear to all users. In this work, seven hydrocyclone models were evaluated. They are the more theoretically oriented models by Bohnet, Braun, and Mueller, semi-empirical models by Schubert/Neese and Svarovsky, plus the empirical models by Plitt and Krebs Engineers. Plant operation data from the Dow Chemical Company were used to compare with the predictions from these models. It was found that most of the models studied work well for certain cases but none of the models can predict all applications. The best results are obtained by using more than one model for predictions. Some experimental data are very important in choosing the models.     

改进的模糊层次综合评判法在重大风险源评价中的应用

以石油化工、煤化工及制药行业涉及到的危险装置、设施构成的危险源为研究对象。在简要介绍分析我国目前采用的几种重大危险源评价方法的基础上,针对重大危险源评价因子建立层次结构模型,运用改进的层次分析法确立模糊一致性矩阵,进而计算出综合评价结果并对其分级,并借鉴安全预警体系中的红、橙、黄、绿,作为分级结果的警示色,为重大风险源的预防与控制提供了科学依据。并通过实例进行了基于改进层次分析法的重大危险源评价方法的实际运用。     

Experimental investigations on a cyclone separator performance at an extremely low particle concentration

In order to evaluate the influence of extremely low particle concentration on separation performance of cyclone separator, the overall collection efficiencies and grade efficiencies of a cyclone separator with particle concentrations of 5-2000 mg/m³ and inlet velocities of 6-30 m/s have been investigated under ambient temperature and atmospheric pressure conditions. Aerosol spectrometer based on measuring particle number is used to measure the particle concentrations and particle size distributions of the inlet and outlet of the cyclone separator. The overall efficiency is equal to the ratio of the particle concentration difference between the inlet and outlet of the cyclone separator to the inlet particle concentration. The grade efficiency is obtained by comparing the particle size distributions of the inlet and outlet of the cyclone separator. The effects of particle concentration on separation performance are predicted by Smolik empirical model. Particle agglomeration, which has been found in the inlet and outlet of the cyclone separator, has a very important influence on the collection efficiencies and grade efficiencies of the cyclone separator at the particle concentration of 5-2000 mg/m³. The cut sizes for different inlet gas velocity with extremely low particle concentration can be quantitatively calculated by Barth model, Mothes and Loffer model and Muschelknautz model, respectively. Experimental results show that the overall collection efficiencies and grade efficiencies increased with the increasing particle concentrations and inlet velocities, and most of the particles with the diameter bigger than 10 μm can be removed by cyclone separator.     

磁选柱分选攀钢选矿厂粗精矿的试验研究

用Х３０ｍｍ磁选柱双攀钢选矿厂粗精矿进行实验室试验。结果表明,通过对粗精矿分级选别,取得了良好的指标：粗精矿铁品位由４６．８９％提高到５３．４０％,回收率达９３．９１％。建议进行半工业或工业试验进一步验证磁选柱分选的效果,并进行经济效益分析。     

基于须弥山竖向空间模式的山地佛教建筑布局研究 #——以清代皇家园林为例

对须弥山世界竖向空间结构图形化,结合文献研究确定了“标高由下至上等级逐渐升高”与“顶点具有特殊佛学意义”两方面空间特性。运用个案研究的方法,取例于清代皇家园林里位于具有高差变化的山地中的佛教建筑,从上述新角度对清代皇家园林中山地佛教建筑布局进行再描述,并为之设计意匠增添了佛学语义层面新解释。     

基于GoS优化的增强型呼叫准入控制算法

提出一种用于无线多媒体网络增强型速率降级呼叫准入控制算法,在新窄带呼叫请求到达时对宽带呼叫速率的降级程度进行优化,从而实现最优化呼叫层的服务等级(GoS)。利用马尔可夫模型对算法进行分析,通过分析结果及各种呼叫的到达速率,采用穷举法获得最佳门限值。数值仿真结果表明,与传统的非优化速率降级方案相比,该算法能够获得更好的GoS。     

电子级HEA制备中痕量钠钾离子吸附及过程模拟

丙烯酸羟乙酯(HEA)是一种应用广泛的化工原料,目前电子级HEA分离纯化的研究文献报道较少。本工作采用离子交换树脂吸附方式,在去除Na+和K+的同时避免了HEA自身高温环境下发生聚合降低产品纯度的问题。通过树脂静态吸附实验,拟合得到HEA中Na+和K+的动力学模型及特性;通过比较Langmuir等温吸附模型与Freundlich吸附模型的拟合度,选择拟合度更好的Langmuir模型,并由此得到的Langmuir等温吸附线获得Na+与K+树脂最大吸附量。通过动态吸附实验获得Na+及K+在该树脂上的穿透曲线,并通过Aspen Adsorption模拟动态吸附过程,得到床层工作状态与吸附时间的关系,实验值与模型值符合良好。因此,模拟结果为电子级HEA的应用提供了相关参数及数据支持。