低温城市污水处理污泥特性试验研究

低温条件下（15～3℃）,在活性污泥法处理城市污水实验室研究过程中,对污泥浓度、污泥沉降性能、粒度、胞外聚合物（EPS）、脱氢酶活性、摄氧速率、污泥膨胀进行了研究。研究结果表明：随着温度降低,污泥沉降性能变差,引起沉降性能变差的原因是污泥浓度与胞外聚合物共同作用的结果;温度降低过程中,胞外聚合物分泌量呈增大趋势;微生物活性降低,并在15～13℃间降低变化明显;产生污泥膨胀现象的原因可能是丝状菌黏性物质分泌过多造成的。     

低温活性污泥 EPS 特性及其对污泥沉降性能影响试验研究

以长春市某污水处理厂初沉池出水为原水在实验室进行了低温污水处理模拟试验,研究了低温活性污泥 EPS 特性及其对污泥沉降性能的影响。试验温度控制在15℃、13℃、11℃、9℃、7℃、5℃、3℃,7个温度下,在处理效果稳定的条件下,检测分析了活性污泥中胞外聚合物（EPS）、沉淀性能,研究了其变化规律并探讨了相关性。研究表明活性污泥中 EPS 的含量随温度的降低而减少,而 EPS 中的多糖含量则随之升高,导致活性污泥的沉降性能也随温度降低而变差。     

污泥掺烧对燃煤电站锅炉热效率的影响

研究高效、节能的污泥处理技术对环境保护有重要意义.通过热力计算详细分析了420 t/h的燃煤锅炉掺烧含水率为20%的干化污泥时,不同污泥掺烧比例对燃煤电站锅炉排烟温度、排烟热损失和锅炉热效率等参数的影响.结果表明,当掺烧比由0增加至10%时,锅炉排烟温度从1 109.5℃上升到1 125.8℃、空气预热器出口烟温从145℃上升到168℃、减温水量从11 t/h增加到26 t/h、热效率从90.6%下降到88.2%、燃煤量从69 900 t/h减少到67 830 t/h.     

温度对UASB厌氧氨氧化反应器运行性能的影响及其过程动力学特性

本研究通过阶梯降温方式考察了温度对上流式厌氧污泥床(UASB)厌氧氨氧化反应器脱氮性能的影响。试验结果表明,23℃是UASB反应器脱氮效能的转折点,温度大于23℃时UASB反应器可稳定高效运行,容积氮去除率(NRE)维持在87%左右;温度小于23℃时,NRE大幅度下降,但适当延长污泥驯化时间及降低容积氮负荷(NLR),NRE均缓慢回升且大致保持稳定在85%.温度由8℃提高至13℃时,逐渐提高系统进水NLR(由3.55 kg/(m~3·d)提高至5.16 kg/(m~3·d)),系统可实现良好的脱氮性能(NRE大致为84.19%).动力学分析表明,长期降温过程中的容积氮去除负荷(NRR)与温度之间的关系较好地符合改进的Stover-Kincannon模型,且活化能(E_a)随温度的降低而增加。但长期处于最适温度条件下的厌氧氨氧化菌受温度变化的影响更大,而低温驯化有助于提高厌氧氨氧化菌对温度的适应性。     

北方冬季污水处理厂活性污泥特性实验研究

该文对北方冬季污水处理厂来水水温为7～15℃时,曝气池中活性污泥沉降性能、粒度、比耗氧速率(SOUR)和脱氢酶活性进行研究.结果表明:温度升高,MLVSS/MLSS和SVI增大;温度越低,粒径越小,比表面积越大;比耗氧摄取速率随温度降低而变小;脱氢酶活性随温度升高而增大.     

双香豆素在SBR工艺中污泥减量化作用的研究

目的试验探究解偶联剂双香豆素在SBR工艺系统中对活性污泥的减量化作用以及对工艺运行效能的影响.方法利用动态SBR反应器模拟SBR工艺,不同质量浓度(0.3 mg/L、1 mg/L、3 mg/L、6 mg/L、10 mg/L)双香豆素投加到工艺系统中进行试验.结果双香豆素能有效降低污泥产率.当双香豆素质量浓度为10 mg/L时,产率较空白组降低了32.4%.双香豆素在低质量浓度范围对氨氮的去除影响不明显.在质量浓度为10 mg/L时,对COD的去除率表现出一定程度下降,去除率均值为77.9%,比空白阶段下降9%.在研究双香豆素对污泥沉降性以及活性的影响时,结果显示:双香豆素对污泥沉降性有较小影响,当双香豆素浓度为10 mg/L时,SVI值由空白组的70.8升高至77.8.结论双香豆素对污泥的活性影响较显著,能够明显提高污泥的脱氢酶活性及呼吸速率.双香豆素对污泥减量化效果显著.     

添加剂对石灰含硼高硅高硫铁水脱硫的影响

采用喷吹方法,研究了添加剂对活性石灰脱硫的影响.结果表明,当铁水中添加0.1%Al,活性石灰用量仅为13 kg/t时,即可使硫质量分数从0.1%降至0.005%;铁水中添加Al后石灰界面反应层主要由铝酸钙、铁酸钙及硫化钙组成,在1 400℃实验温度下为熔融态,有利于硫的扩散;当活性石灰中添加25%CaCO3,3%CaF2粉,石灰用量为15 kg/t时,也能使硫质量分数从0.1%降至0.01%以下;含硼铁水温度高是采用活性石灰脱硫的有利条件.     

温度和SRT对污泥高温好氧预处理的影响研究

为使高温好氧预处理反应器达到杀灭病原菌和稳定运行的效果,以剩余污泥为研究对象,通过试验确定其最佳运行温度和固体停留时间SRT．采用两个有效容积为8L的反应器,SRT为1d和1．5d,将它们分别运行在55℃、60℃、65℃,当温度大于60℃、SRT≥1d时,粪便大肠杆菌的密度从大于10^6MPN／gTS降到小于10^3MPN／gTS．污泥经高温好氧预处理后,VFA比进泥提高了1～2倍,同时COD降低了20％～30％．在试验条件下VS去除率为25％～32％,当温度由55℃上升到65℃时,VS去除率有5％左右的提高．试验结果表明,对污泥高温好氧预处理取温度60～62℃．SRT=1d是较为适宜的。     

常温生活污水EGSB反应器颗粒污泥的特性

为研究生活污水EGSB反应器内的颗粒污泥特性,考察了运行条件的影响.结果表明,15℃以上时缩短水利停留时间(HRT)可提高COD去除率.HRT从1.6 h缩短至0.6 h,平均COD去除率从77%增加至82%.水力和基质的过负荷都会加速颗粒污泥解体.上升流速为2.8～3.1 m/h、容积负荷率(VLR)低于(12.9±7.6)kg/(m3·d)时,污泥粒径分布相对稳定;上升流速为3.8 m/h、冲击负荷为38 kg/(m3·d)时,则造成明显的污泥解体.高负荷运行有利于增加颗粒内部生物密度,但过度剪切造成的污泥破碎和粒径过小也会加剧洗出,尤其在低温条件下.缩短HRT可提高颗粒污泥活性.20℃以上,HRT从1.6 h缩短至0.75 h后,污泥比产甲烷活性(SMA)由0.85 g/(g·d)(VSS)增加至1.11g/(g·d)(VSS).长期低温驯化后,甲烷菌得以富集,10℃、HRT为2 h时,SMA增加至1.21 g/(g·d)(VSS).扫描电镜观察发现,颗粒污泥不同部位呈现明显的菌群分区现象.     

卷取温度对热轧F/B双相钢组织性能的影响

采用轧后空冷+超快速冷却工艺,研究卷取温度对热轧铁素体/贝氏体(F/B)双相钢组织性能的影响规律.结果表明:卷取温度由504℃降至250℃时,铁素体体积分数变化很小(857%～878%),铁素体晶粒尺寸变化也很小(36～37μm),组织中的硬相由以贝氏体为主转变为以马氏体为主;实验钢的抗拉强度由510MPa升至597MPa,屈服强度由475MPa降至389MPa,延伸率变化较小(322%～350%).另外,随着卷取温度的降低,铁素体与贝氏体或马氏体间的变形协调能力降低,使扩孔过程中微孔提前形核,同时加快了已有微孔的长大及合并过程,导致试样发生的塑性变形减小,扩孔性能降低,扩孔率由1014%降至524%.     

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.     

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     

Journal of Donghua University ( English Edition) Contents of Volume 31

正~~     

Brief Introduction to “Journal of Jilin University( Science Edition) ”

<正>"Journal of Jilin University(Science Edition)"is a comprehensive academic journal in the fields of science sponsored by Jilin University and administrated by the Ministry of Education of the Peoples Republic of China.The journal started publication in 1955.The original name at starting publication was"Journal of Natural Science of Northeast People University",which was changed into"Acta Scientiarum Naturalium Universitatis Jilinensis"in 1958 owing to the name change of the university.The present journal name has