Distribution of Extracellular Polymeric Substances in Pilot-Scale Membrane Bioreactor

The spatial distribution of extracellular polymeric substances (EPS) in a pilot-scale membrane bioreactor (MBR) was studied. The sampling points on top of and inside the membrane module were measured and analyzed by the experimental variant function. The content of EPS was spatially interpolated by ordinary Kriging method, and illustrated with SURFER software. A case study was carried out in an MBR with membrane aperture of 0.4 μm and handling capacity of 120 m3/d in Jizhuangzi sewage treatment plant, Tianj...     

Membrane fouling behavior and microbial community succession in a submerged membrane bioreactor treating harbor oily wastewater

A membrane bioreactor (MBR) was established for treating harbor oily wastewater. It showed good removal performance for chemical oxygen demand (COD), oil content, suspended solids (SS), and other pollutants. However, serious membrane fouling occurred. It was recognized that the extracellular polymeric substances (EPS) accumulated on the membrane surface, especially the proteins, were of great importance for the transmembrane pressure (TMP) increment and membrane fouling. The MBR was optimized via improving aeration rate and reducing the ratio of A_r/A_d (A_r and A_d are the cross-sectional areas of the riser and the downcomer of the MBR). The increasing rate of TMP was slowed, indicating that the optimization strategy could effectively mitigate membrane fouling. Microbial community evolution was monitored and analyzed by polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE), cloning, and sequencing of 16S ribosomal ribonucleic acid (rRNA) fragments. Results revealed that low community shift occurred during the whole operational period. Geobacter sp. and Rhodocyclales sp., which have also been identified by other studies in a petroleum refinery wastewater MBR or an infiltration basin receiving highway runoff, dominated in the MBR system throughout. Comamonas sp. was thought to accommodate the lower aeration rate in this study, while Rhodocyclales sp. preferred the higher aeration rate. In addition, during the operational time under high organic loading rate, a few species were present in abundance, and may have been responsible for the good removal performance at this time.     

城市河道黑臭水体综合治理工程实例分析

针对某市河道黑臭水体的特性及污染物特点,采用"膜生物反应器(MBR)一体化工艺、补氧+生物膜、人工清淤"综合治理技术对其进行治理。实际治理结果表明,MBR一体化工艺出水水质达到了《城市污水再生利用景观环境用水水质》(GB/T18921-2019)的要求;补氧与生物膜的组合应用最大程度地消除了黑臭现象;采用人工清淤方式对河床内淤泥进行了全部清除,消除了内源污染;工程运行费用为70.39万元/年。该综合治理技术治理河道黑臭水体效果良好,适合在其他类似项目中推广应用。     

Effects of vibration technology and polyvinyl acetate emulsion on microstructure and properties of expanded polystyrene lightweight concrete

To prevent expanded polystyrene (EPS) beads from rising up to the surface in the molding process of EPS lightweight concrete, vibration with pressure was applied and the polyvinyl acetate (PVA) emulsion was adopted to im-prove its mechanical properties. The mechanical properties, thermal properties and durability of EPS lightweight concrete were tested. The microstructures of EPS lightweight concrete were observed by scanning electron microscope (SEM). Vibration with pressure reduces the number of small cracks. The 180 d compressive strength and flexural strength increase obviously as a large amount of PVA was added. The mixed amount of PVA has no obvious influence on the thermal per-formance when it is not more than 10% of the cement. Vibration with pressure and surface modification of EPS beads by PVA improve the combination of EPS beads with cement stone and the mechanical properties of EPS lightweight con-crete.     

颗粒填料复合式膜生物反应器（HMBR）技术研究

膜污染是制约膜生物反应器（MBR）工程化应用的瓶颈。针对现有MBR存在的缺点,本文提出了新型的颗粒填料复合式膜生物反应器（HMBR）,并介绍了HMBR在工业废水处理中的应用。通过分析悬浮颗粒物在膜表面的沉积条件,从流体力学、微生物学、水处理工艺学、亚微观动力学等方面对HMBR的性能和特点进行了详细阐述,表明颗粒填料可以有效地减缓膜污染和提高膜生物反应器过滤性能。     

PAC-MBR工艺处理微污染地表水的研究

设计了膜生物反应器 (MBR)与粉末活性炭 (PAC)联合使用的膜组合工艺 (PAC MBR)处理微污染地表水 ,并用分子量分析方法来考察PAC MBR组合工艺及各单元工艺对有机物的去除效果 .分析结果表明 ,由于原水中的小分子有机物难生物降解 ,该工艺出水有机物集中在小于 1k的分子量区间内 ,活性炭的投加能显著提高这部分有机物的去除率 .试验证明 ,PAC MBR工艺中生物处理与活性炭吸附互相促进 ,在稳定运行阶段对CODMn、UV2 54 、UV4 10 和氨氮的去除率分别达到 70 %、70 %、10 0 %和 92 % .     

公共英语演讲课程中的思辨技能培养——基于医学生专业学习需求的教学探索

对当下医学院校的公共英语演讲课程做出了三点调整:一是将公共英语演讲课程的定位从跨文化交际类通识课逐渐过渡到专门用途英语课.二是在教学内容的选择上凸显医学学科特色;提升对思辨能力的系统性认识;增加对说理演讲的学习,达到专业、技能、思辨的深度融合.三是在教学模式上,采用线上线下混合式教学.通过上述方法并举,力求使医学院校开...     

干/湿纺制初生中空纤维膜数学模型的数值模拟

In an effort to find the effect of mass transfer ,surface tesion and drag forces on the velocity distribution,the mathematical model of the velocity profile of a nascent hollow fiber during membrane formation in the air gap region was numerically simulated by using the Runge-Kutta method (fourth-order method).The effect of mass transfer on velocity distribution based on the complicated function(G(Ch^s))was presented and the dffects of a complicated function were studied in two cases:in the first case,G(Ch^s) was constant;in the second,G(Ch^s) was variable.The latter was done by varying with the concentration of solvent in a nascent hollow fiber through the air-gap region.One empirical equation was used to describe this change and the predected values had a better agreement with the experimental values.To verify the moedl hypotheses,hollow fiber membranes were spun from 20:80 polybenzimidazole/polyetherimide dopes with 25.6 wt％ solid in N,N-dimethylacetamide (DMAc) using water as the external and internal coagulants.Based on the experimental results of dry-jet wet-spinning process for the fabrication of hollow fiber membranes,it is found that the model calculated values were in a good agreement with the experimental values.     

Responses of phospholipase D and lipoxygenase to mechanical wounding in postharvest cucumber fruits

This study was to investigate the responses of phospholipase D (PLD) and lipoxygenase (LOX) to mechanical wounding in postharvest cucumber (Cucumis sativus L. cv. Biyu-2) fruits. Membrane-associated Ca²⁺ content, activities and gene expression of PLD and LOX, and contents of phosphatidylcholine (PC), phosphatidylinositol (PI), and phosphatidic acid (PA) were determined in cucumber fruits following mechanical wounding. Results show that PLD and LOX activities increased with the PLD and LOX mRNAs which are upregulated upon wounding, while membrane-associated Ca²⁺ content decreased. Accompanying with the increase of PLD and LOX activities, accumulation of PA and losses of PC and PI were observed in all fruits, but there were differences of degrees between wounded and control fruits. Results suggest that PLD and LOX might be the main hydrolytic enzymes of phospholipids in postharvest cucumber fruits participating in the mechanical wounding injury. The activation of PLD and LOX might be the result of gene expression, which could be stimulated by the Ca²⁺ flowing from the membrane to the cytoplasm upon receiving the wounding signals.     

浅议每股收益的信息含量

每股收益是证券市场中最为常见的财务指标之一，许多会计报表的使用者经常依赖其作出投资决策，因为他们认为透过该数据能够评价管理当局过去的业绩，同时可以预测公司未来的收益。但过分依赖于公开的每股收益会导致许多失误，每股收益并不具有如此丰富的信息含量。     

The Development of an EPS Information Booklet for Primary Age Pupils

The focus of this paper is based on a research project undertaken in an outer London EPS. The research was in line with recent legislative and policy changes, highlighting the importance of the active participation of children in discussions made about them and their school life. Central to the project was the decision that pupils should be provided with an information booklet, regarding the educational psychologist's (EP) role within the assessment process-and by thus doing, promoting direct access and involvement between the pupil and the EPS. After initial research into this area had been undertaken, a pupil information booklet was produced. This booklet is currently being trialled in all primary schools within the education authority.     

浅析如何提高每股收益信息的使用价值

从公司利润对每股收益的决策作用这个角度，分析了公司利润在确认、计量、报告中存在的质量问题，从而揭示了每股收益信息存在的问题，进而提出解决问题的几点措施。     

Influence of green tea polyphenols on mitochondrial permeability transition pore and Ca2+ transport

The authors investigated the influence of green tea polyphenols (GTPs) on the liver mitochondria permeability transition pore (PTP) opening through mitochondria swelling and change of mitochondria membrane potential. The data showed that GTPs had obvious protective effect on the Ca²⁺-induced PTP opening in a dose-dependent manner detected by mitochondria swelling. The results were obtained by measuring the change of mitochondria membrane potential through Rh 123. Further experiments were conducted to examine the detailed influence of GTPs on Ca²⁺ import and export of mitochondria. The results showed that GTPs had remarkably inhibitory effect on the Ca²⁺-induced Ca²⁺ import in mitochondria; and that they could accelerate Ca²⁺-release from mitochondria. Our data provide an alternate interpretation of the potent protective function of GTPs on cell against apoptosis.     

Implementation and modification of an anatomy‐based integrated curriculum

Morehouse School of Medicine elected to restructure its first‐year medical curriculum by transitioning from a discipline‐based to an integrated program. The anatomy course, with regional dissection at its core, served as the backbone for this integration by weaving the content from prior traditional courses into the curriculum around the anatomy topics. There were four primary goals for this restructuring process. Goal 1: develop new integrated courses. Course boundaries were established at locations where logical breaks in anatomy content occurred. Four new courses were created, each containing integrated subject content. Goal 2: establish a curriculum management team. The team consisted of course directors, subject specialists, and a curriculum director. This team worked together to efficiently manage the new curriculum. Goal 3: launch contemporary examination and question banking methods. An electronic system, in which images could be included, was implemented for examinations and quizzes, and for storing and refining questions. Goal 4: ensure equitable distribution of standardized examinations and course grading systems among all courses. Assessments included quizzes, in‐course examinations, and National Board of Medical Examiners^® (NBME^®) Subject Examinations. A standard plan assigned the contribution of each to the final course grade. Significant improvement was seen on subject examinations. Once the obstacles and challenges of integration were overcome, a robust and efficient education program was developed. The curriculum is expected to continue evolving and improving, while retaining full regional dissection as a core element. Anat Sci Educ 10: 262–275. © 2016 American Association of Anatomists.     

基于PID控制下EPS助力特性的仿真研究

通过数学分析建立了EPS数学模型,应用线性PID控制建立了EPS控制模型．采用MATLAB／sim—ulink仿真软件建立了整个EPS的仿真模型．分别选取不同车速对EPS直线型助力特性进行了仿真实验,结果表明：当车速为0km／h时,EPS向汽车转向盘提供的最大助力转矩为20N·M,当车速为40km／h时,助力转矩减小为9N·M,当车速为80km／h时,助力转矩减为最小5N·M．为此,EPS直线型助力特性能贴近驾驶员对不同车速下的转向轻便性与高速行驶下良好路感性的需求．     

中华猕猴桃果实成熟过程中膜脂过氧化变化研究

研究中华猕猴桃果实成熟过程中脂过氧化的变化，结果表明：MDA含量呈上升趋势，SOD、Vc含量呈下降趋势。SOD、POD酶活性出现二次高峰，SOD、POD活性第一次峰出现时，果实内MDA含量下降；第二次峰出现时MDA含量变化不大，两品种比较，果实内Vc含量高，膜脂过氧化水平低时，果实成熟慢。     

Young people’s views about their involvement in decision‐making

This paper reports on research conducted over a two‐year period in a large Educational Psychology Service (EPS) in England. Researchers were keen to ascertain the views of young people and EPS members about young people being directly involved in educational decision‐making and how their genuine involvement in such decision‐making might be best achieved. Focus groups were employed as a means of gathering data which were analysed using Content Analysis. Young people and EPS members ultimately identified “culture”, “attitudes”, “environment”, and “systems” as being the most important factors in ensuring the genuine involvement of young people in decision‐making.     

电动助力转向系统试验分析

根据EPS在汽车上的实际装配关系,设计了EPS试验台,完成了性能实验(功能试验、助力电流特性试验、转向轻便性试验),并对试验结果进行了分析。试验结果表明EPS系统性能良好,方向盘可操作性好,能很好地实现助力效果。     

中美商务语篇互文性多维对比研究

本研究以互文性为理论框架,运用语料库与定量统计方法,对比分析中美500强上市企业年报文本的互文性特征,试图发现年报互文性特征与企业绩效之间的相关性。研究发现:1)中美总裁致辞在文本特征层面存在差异,中文总裁致辞篇幅较短,少用被动结构和第一人称单复数代词;2)中美年报总裁致辞在互文性特征层面存在共性与差异,均使用直接引语,披露绩效信息存在显著差异,但披露前瞻性信息未见显著差异,两类年报存在语块重复,直接引语的数量与侧重点不同。本研究对商务话语研究、商务英语教学和企业传播具有一定启示。     

三维光学存储系统中补偿折射率失配的复振幅分布

1 Introduction The three-di mensional optical data storage is ofmuch interest in recent years[1-8].It has a great poten-tial for recording density.Currently,thetwo mainfac-tors affecting the density are the wavelength andspherical aberration caused by bot…