重组大肠杆菌BL21(pBAI)生产人干扰素α2b

通过培养重组大肠杆菌BL21(pBAI)表达人干扰素α2b(Human Interferon α2b,hIFNα2b).hIFNα2b表达由PL,启动子控制,通过升温至42℃诱导表达.本研究比较了分批培养和多种补料分批培养方式下hIFNα2b的生产,其中通过恒速流加葡萄糖,hIFNα2b的表达量达到6 540 mg/L,平均生产速率和比速率分别为546 mg/(L·h)和27 mg/(g·h).升温前1.5 h补充25 g酵母提取物,并以0.27 g/(g·h)的比速率供应葡萄糖,hIFNα2b的平均生产速率达到1 006 mg/(L·h),比生产速率为54 mg/(g·h),对有机氮源的得率提高到138 mg/g.     

挥发性有机污染物水中亨利常数的简易测定方法

开发了挥发性有机物亨利常数的简易实验测定方法,并以此方法测定了5种汽油成分(甲基叔丁基醚(MTBE)、苯、甲苯、乙苯、邻二甲苯)的亨利常数,相对标准偏差基本上在5%以内.使用此方法测定的汽油成分、硝基苯、2,4-二氯酚、苯酚和三氯乙烯(TCE)的亨利常数数值比估算值更接近文献值.在不同温度下,使用本方法对MTBE、苯、甲苯、TCE溶液进行测定,结果表明亨利常数随着温度的升高而变大,符合亨利常数随温度变化趋势的一般规律.两种挥发性有机物在混合条件下的亨利常数比单独存在时的亨利常数大.     

气液色谱法测定顺丁烯二酸酐与苯、甲苯、异戊二烯的分子络合常数

以丁二酸二正丁酯和顺丁烯二酸二丁酯为稀释溶剂,用气液色谱法测定了受体顶丁烯二酸酐与给体异戊二烯、苯、甲苯在20℃和25℃下的分子络合常数.对络合反应的生成热也作了估算.     

玻纤负载纳米TiO2光催化降解气相苯

采用玻璃纤维布作为载体制备负载型纳米TiO2光催化剂,对连续流中光催化氧化降解气相苯的过程进行了分析.考察苯的进口质量浓度、相对湿度、氧气体积分数对苯的光催化降解效率的影响,结果表明,相对湿度和氧气体积分数是影响气相苯降解的主要影响因素.利用L-H模型以及水蒸气和氧气质量浓度对表观速率常数的影响,计算得到苯、水分子和氧气的吸附平衡常数分别为:K=6.5×10-3m3/mg,KW=2.2×10-4m3/mg,KO=2.35×10-5m3/mg.     

玉米芯废渣多孔碳的制备及其对液体苯的吸附

以玉米芯废渣为原料、KOH为活化剂,采用化学活化法制备多孔碳材料用于液体危化品苯的吸附.通过热重分析仪、X射线衍射仪(XRD)、扫描电子显微镜(SEM)分析多孔碳的微观结构和表观形貌.研究表明:在碳化温度350,℃、碳化保温时间30,min、m(KOH)∶m(C)=4∶1、活化保温时间120,min的条件下,最佳活化温度为900,℃,KOH的造孔效果最好,制备的多孔碳产品以微孔为主,比表面积达到2,387,m2/g,对苯的饱和吸附量最大为14,235,mg/g.     

TiO2/SiO2 纳米粒子气相光催化降解甲苯的研究

以TiO₂/SiO₂纳米粒子为催化剂, 研究了甲苯的初始浓度、 氧气和水蒸气含量及光强等对其光催化氧化降解的影响. 甲苯初始反应速率随其初始浓度的增加而增大, 最终趋于稳定. 氧气含量增加, 甲苯反应速率增大, 氧气含量增至18％时, 抑制反应速率增加. 水分子含量对甲苯反应速率的影响也有最佳值0.2％（体积比）. 甲苯的反应速率随光强增加而增大, 在3 mW/cm²时, 反应速率趋于定值. 采用Langmuir-Hinshelwood动力学模型得到甲苯光催化降解的反应速率常数和吸附常数, 并通过FI-RT和GC-MS初步确定了反应产物.     

PVA包埋微球粒径对短程反硝化动力学影响

以聚乙烯醇(PVA)包埋反硝化污泥,制得粒径为2.7、3.6和4.8,mm的3种包埋微球,考察p H值、温度和溶解氧(DO)对不同粒径微球的短程反硝化过程的影响.结果表明,微球在厌氧条件下对NO2--N的降解符合零级反应动力学模型,且随粒径的增大,NO2--N降解速率(以NO2--N计)由14.2,mg/(L·h)降至13.3,mg/(L·h).与游离污泥相比,包埋微球对p H值和温度的耐受范围显著扩大.在p H=5.7时,粒径2.7、3.6和4.8,mm微球的NO2--N比降解速率(以N/MLVSS计)分别是游离污泥的1.5、1.8和2.1倍;而4,℃和48,℃时,不同粒径微球的NO2--N比降解速率差异并不显著.当DO为0.5~0.7,mg/L和1.0~1.2,mg/L时,受到NO2-和O2传质的双重影响,粒径为3.6,mm的微球表现出最高比降解速率(22.0和16.2,mg/(g·h)),是相同条件下游离污泥的2.8和8.0倍.     

曝气生物滤池处理城市污水的中试研究

通过中试系统的运行,研究了表面水力负荷q、温度及气水比等工程控制参数对曝气生物滤池处理城市污水效果的影响。结果表明,温度对微生物的代谢水平具有显著影响,适宜的温度应控制在不小于15℃水平;在20℃的条件下,即便在q高达3.0m3/(m2·h)时,其出水的SS,COD和NH4 -N浓度也可分别保持在15mg/L,60mg/L,18mg/L以下;在q为3.0m3/(m2·h),20℃的条件下,曝气生物滤池用于处理生活污水时,气水比控制为3是比较合理的。     

淮北煤田任楼煤矿煤的不同显微组分热解特征

为了给任楼煤矿煤的分级利用提供理论指导,在显微组分分离的基础上,进行了各显微组分热解实验。结果表明:随着热解温度的升高,3种显微组分在400～570℃均出现明显的失重现象,壳质组在400℃左右开始热解,失重速率峰温约为450℃,失重率大;镜质组和惰质组在420℃开始热解,失重峰温约为475℃。壳质组在整个热解过程中失重率为39%,平均最大热解速率为0.95 mg/(g·min);镜质组失重率为32.5%,平均最大热解速率为0.53 mg/(g·min);惰质组失重率为29.5%,平均最大热解速率为0.49 mg/(g·min)。     

蒙脱石对乙基钾黄药-铅复合污染体系的吸附平衡与动力学

为揭示黄药-重金属复合污染体系的环境行为,以蒙脱石为吸附剂进行静态吸附试验,探讨乙基钾黄药-铅复合污染体系的吸附平衡与动力学特征。研究结果表明:乙基钾黄药在蒙脱石上的吸附作用很小,它通过与Pb2+反应形成悬浮态物质而严重影响Pb2+在蒙脱石上的吸附作用,使Pb2+的吸附速率常数由10.40 g/(mg.min)提高到54.76 g/(mg.min),而平衡吸附量(qe)则由9.80 mg/g降低到4.27 mg/g;影响程度随着乙基钾黄药浓度的升高而增大,随着Pb2+浓度、pH和蒙脱石投加量的升高而减弱。研究结果可为黄药-重金属复合污染环境的治理提供参考。     

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.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

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