污水移动床连续过滤过程的数值模拟研究

通过建立数学模型对污水固定床和移动床过滤过程运行特性进行了模拟分析,该模型包括滤料和污水质量衡算方程、滤层过滤动力学方程和滤层压降计算方程。对固定床过滤过程的模拟结果表明,在一个过滤周期内随时间增加,污水过滤的负荷由顶部向底部滤层逐渐转移,滤出水的水质逐渐变差,同时滤层的总压降逐渐增加,经过足够长的过滤时间后,整个滤层将达到饱和状态从而过滤失效。对移动床过滤过程的模拟结果表明,在移动床过滤期间,滤料由上到下得到逐渐更新,滤层过滤能力得到恢复,滤出水的水质变好,滤层的总压降减小。     

污水移动床连续过滤过程的数值模拟研究

通过建立数学模型对污水固定床和移动床过滤过程运行特性进行了模拟分析，该模型包括滤料和污水质量衡算方程、滤层过滤动力学方程和滤层压降计算方程。对固定床过滤过程的模拟结果表明，在一个过滤周期内随时间增加，污水过滤的负荷由顶部向底部滤层逐渐转移，滤出水的水质逐渐变差，同时滤层的总压降逐渐增加，经过足够长的过滤时间后，整个滤层将达到饱和状态从而过滤失效。对移动床过滤过程的模拟结果表明，在移动床过滤期间，滤料由上到下得到逐渐更新，滤层过滤能力得到恢复，滤出水的水质变好，滤层的总压降减小。     

新型过滤装置的工作参数对过滤性能的影响

在前期研发的一种新型一体化连续过滤装置的基础上,分别研究了滤料级配、提砂反冲洗系统的工作参数、进水流量以及不同过滤方式对该装置过滤性能的影响,调查了连续过滤过程中滤床的反粒度分布以及各种条件下出水水质.实验结果表明:不同的滤料级配对过滤后水质有较大的影响,反粒度自然分布能够提高滤床的截污能力;滤床的更新速率在6.25,mm/min时,过滤后水质更好;连续过滤与间歇反冲洗过滤可以优化组合,在一个间歇反冲洗周期之后,滤床中滤料的清洁程度可以保持良好,与连续反冲洗过滤相比,耗水率可降至5%,.     

论纤维过滤技术的新进展——柔性自反馈纤维过滤技术

论文介绍、分析了＂自然堆积式＂和＂有序装填式＂等纤维过滤技术的特点,阐述了结合两类滤床优势的柔性自反馈纤维过滤技术的原理。该技术有效解决了纤维滤料过滤与清洗相矛盾的难题,其过滤精度高,运行成本低,滤料使用寿命长,设备结构简单、操作方便、基本免维护。     

深床过滤的微观理论模型

与通常的深床过滤理论研究不同，本研究以滤料的微观流体力学和传质过程分析为基础，结合胶体稳定性理论及溶液与表面络合化学原理建立深床过滤过程的微观理论模型。它包括物理和化学两个方面。在实验室理想过滤系统中对模型进行了实验验证，力图为深床过滤工艺设计与运转提供科学根据。     

级配砂滤层过滤系数的研究

滤层过滤的数学模式与过滤系数λ有关.而已往表达λ的模式比较复杂,包含多个与滤料粒径有关的待定常数.此外,许多模式是以均匀滤料为依据,不适用于级配滤料. 本文假定,λ是滤层水力梯度和缝隙流速的函数,据此导出级配滤料层λ和σ关系的模式.并根据等速过滤实验数据、用计算机求解过滤方程来验证模式。理论和实验结果基本一致.     

含油污水滤床过滤性能试验研究

在油田污水处理系统中,过滤装置性能的好坏对整个污水处理工艺的效果有直接影响。对含油污水滤床过滤特性进行了试验研究,考察了滤料种类以及滤速等因素对污水过滤效果和压降的影响。研究结果表明,在石英砂、无烟煤和核桃壳3种滤料中,核桃壳对污水中原油的过滤效果较好,核桃壳和石英砂对污水中固体悬浮物的过滤效果较好;颗粒粒径较大的无烟煤滤层压降较小,核桃壳和石英砂滤层压降较大。不管何种滤料,污水在滤层中的压降随滤速的增加均单调增加。对污水中原油的去除效果来说,无烟煤和核桃壳随滤速的增加过滤效果变差,但对于石英砂滤料,在试验滤速范围内随着滤速的增加,污水的过滤效果却变好。     

含油污水滤床过滤性能试验研究

在油田污水处理系统中，过滤装置性能的好坏对整个污水处理工艺的效果有直接影响。对含油污水滤床过滤特性进行了试验研究，考察了滤料种类以及滤速等因素对污水过滤效果和压降的影响。研究结果表明，在石英砂、无烟煤和核桃壳3种滤料中，核桃壳对污水中原油的过滤效果较好，核桃壳和石英砂对污水中固体悬浮物的过滤效果较好；颗粒粒径较大的无烟煤滤层压降较小，核桃壳和石英砂滤层压降较大。不管何种滤料，污水在滤层中的压降随滤速的增加均单调增加。对污水中原油的去除效果来说，无烟煤和核桃壳随滤速的增加过滤效果变差，但对于石英砂滤料，在试验滤速范围内随着滤速的增加，污水的过滤效果却变好。     

新型颗粒移动床连续过滤装置的特性研究

改变传统固定床过滤装置的间歇操作,降低过程能耗,集清洗洗涤器、三相分离器及滤料"反粒径"分布三项技术,开发了一种新型颗粒移动床连续过滤装置,讨论进气速率、清洗水速率以及移动床滤层更新速率之间的相互关系,探讨最佳运行条件.结果表明:进气速率和清洗水速率要有合适的比例才能保证装置稳定运行,连续操作的最佳气水体积比为7~12,此时移动床滤层更新速率很快,滤料循环最小周期只需12min;滤料由进水口到出水口粒径呈现由大到小的"反粒径"自然分布;随着处理负荷的增加,移动床比固定床有更好的出水水质;水力停留时间和进水浓度对出水效果和去除率具有很大的影响,浊度和化学需氧量的去除率最高可达88.89%和83.48%.     

纤维过滤介质在容尘阶段的非稳态过滤效率

基于黏性牛顿流体的N-S方程,从一般控制方程的通用形式,结合纤维过滤介质的积尘填充率与粉尘颗粒或气溶胶微粒沉积量,推导出纤维多孔过滤介质内粒子浓度分布的非线性微分方程.分析了过滤效率经验公式中无量纲参数之间的内在联系及其对纤维滤料在容尘阶段过滤效率的影响,利用非线性回归方法拟合出纤维过滤介质的非稳态过滤效率经验公式.结果表明:微粒的Re数均小于1,即空气的流动均处于斯托克斯区域,同时其流动状态为层流;计算得到的拦截参数为0.086～0.559.根据实验结果拟合的纤维滤料在容尘阶段的过滤效率经验公式适用于St小于1的场合.     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with