采用优势菌降解BTEX和石油烃的性能

针对石油开采对土壤的污染问题,采用从辽河油田石油污染土壤中筛选出的石油烃优势降解菌(B3、B6、F3)降解土壤中苯、甲苯、乙苯和二甲苯(BTEX)。考察降解时间、通氧量、N/P比、pH、接种量和含油量等对菌株降解石油烃效果的影响。在BETX初始质量浓度分别为1.90、3.64、3.46、6.78(g·m-3)时,菌株对BTEX降解率分别为1.6%～16.8%、12.6%～18.7%、10.0%～13.3%、10.2%～21.1%。真菌曲霉属(Trichoderma sp.)F3菌株对BTEX降解效果最好。含油量对菌株降解石油烃效果影响最大。实验结果为微生物修复石油污染土壤提供一定理论依据。     

陕北地区高效石油降解菌的筛选及其对油污土壤的修复研究

通过筛选陕北地区的高效石油降解菌,为后续的土壤修复提供优良的菌种资源。本研究的石油降解菌分离来自延安市延长县某油井的土壤样品,通过以石油为唯一碳源,进行筛选、富集培养和平板划线分离,得到可降解石油的菌株,并采用紫外可见分光光度法测量其对富集培养基中的石油降解率。利用PCR扩增技术对筛选的石油降解菌的16S r DNA序列进行扩增,通过对16S r DNA序列的测定和NCBI数据库集进行基因序列比对确定其种属;在被石油污染过土壤中加入筛选出的石油降解菌进行修复试验,经50 d的修复反应,测定石油降解菌对油污土壤中石油的降解效率;最后通过种植小麦检验石油降解菌的降解效果。共筛选出3株高效的可降解石油的菌株:W1、W3、N4,三株菌均可以在以石油为唯一碳源的环境中生长,它们在富集培养基中的石油降解率分别为42. 55%,37. 18%和33. 57%,利用分子生物学技术对三株菌进行鉴定,结果是W1菌株为假单胞菌属,W3菌株为芽孢杆菌属,N4菌株为红球菌属。在菌株对油污土壤修复的研究中,菌W1和菌W3分别对油污土壤进行50 d的降解,土壤中石油量得到很大程度的降解,W1菌株的降油率为52. 20%,W3菌株的降油率为47. 84%,修复后土壤的质量对于小麦的生长没有影响。通过本研究课题,为陕北地区石油污染土壤修复提供了优良的菌种资源,同时为陕北地区的石油污染土壤的微生物修复提供了一定的科学依据。     

辽河油田冻融石油污染土壤中原位修复微生物

以辽河油田不同年代开采油井附近采取的土壤样品为研究对象,通过冻融模拟试验和采用选择性培养基筛选对石油污染土壤具有原位修复作用的优势微生物菌株,并比较油田冻结土壤与未冻结土壤中石油降解细菌与真菌的数量变化特征及其对石油的降解能力.结果表明,从未冻结土壤中筛选出石油降解细菌14株、石油降解真菌6株;从冻结土壤中筛选出石油降解细菌5株、石油降解真菌2株.石油降解细菌假单胞菌属(Pseudomonas sp.)的B3号菌株在37℃、7天时间内对石油的降解率最高,为30.2 %;石油降解真菌木霉属(Trichoderma sp.)的F3 号菌株在28℃、7天时间内对石油的降解率最高,为47.2 %.     

土壤中耐低温石油降解菌的优选、鉴定及降解性能分析

在低温条件下,从大港油田的石油污染土壤中富集分离出31株耐低温菌,在10℃经初步降解试验,优选出对原油的解率分别为47.64%和39.81%的耐低温高效菌株D17和D24,经鉴定分别为副球菌属和盐单孢菌属.进一步对2株高效菌在10℃进行土壤降解试验,单独投加D17,D24的除油效果明显高于不加菌的除油效果,在10℃经过15d,D17使每7 g土壤中的石油烃含量减少86.5 mg;D24使每7 g土壤中的石油烃含量减少15.8 mg.其中菌种D24的降解组分GC-MS分析表明,D24对饱和烃的降解贡献不大,对芳烃组分有较大程度的降解,且对芳烃重质组分的降解性能高于对轻质组分的降解性能.     

海洋石油降解菌的筛选与降解性能研究

从大连港表层被石油烃污染的海水中筛选出14株石油降解菌,并从中选出了一株优势菌(命名为HD-1)。通过16Sr DNA方法鉴定该菌株属于厦门栖东海菌属。该菌株接种后前1 d为对数增长期,2~10d为稳定期,10d后细菌密度下降。温度,营养盐和接种量都显著影响该株菌的石油烃降解效率:最佳降解温度为22℃,最佳氮源磷源组合为氯化铵+磷酸氢二钠。     

土壤中耐低温石油降解菌的优选、鉴定及降解性能分析

在低温条件下,从大港油田的石油污染土壤中富集分离出31株耐低温菌,在10℃经初步降解试验,优选出对原油的解率分别为47.64%和39.81%的耐低温高效菌株D17和D24,经鉴定分别为副球菌属和盐单孢菌属.进一步对2株高效菌在10℃进行土壤降解试验,单独投加D17,D24的除油效果明显高于不加菌的除油效果,在10℃经过15d,D17使每7 g土壤中的石油烃含量减少86.5mg;D24使每7 g土壤中的石油烃含量减少15.8 mg.其中菌种D24的降解组分GC-MS分析表明,D24对饱和烃的降解贡献不大,对芳烃组分有较大程度的降解,且对芳烃重质组分的降解性能高于对轻质组分的降解性能.     

石油降解菌株的筛选、初步鉴定及其特性

从含油污水中分离得到5株能高效降解石油的微生物菌株(P1、P2、P3、P4、P5). 根据形态学观察和生理生化实验对菌株进行鉴定,P1为节杆菌属(Arthrobacter sp.),P2为邻单胞菌属(Plesiomonas sp.),P3为假单胞菌属(pseudomonas sp.),P4为芽孢杆菌属(Bacillus sp.),P5为黄单胞菌属(Xanthomonas sp.). 对这5株菌的特性进行了研究,结果表明, P1、P2、P3、P4、P5在水样pH分别为9、7、8、8、8时,出现最大降解率,在10 g/L原油培养基中培养7 d分别能降解50.20%、55.59%、61.90%、55.66%和55.95%的原油. 接种量、盐度、通氧量、温度、油质量浓度、营养盐对石油的降解率有较大的影响. 通过对残油组分的GC-MS分析,确定各菌对C7～C17的直链烃有较好的降解效果.     

一株烃降解菌的分离鉴定及耐盐机制

随着科学技术与工业经济的发展,石油的开采量也在逐年提升,在其开采以及加工处理过程中会产生大量含有较高盐分的含油废水难以处理,因此对高耐盐度烃类降解菌的筛选极为重要。从新疆油田石油污染土壤中分离得到一株以柴油为唯一碳源的耐盐菌株HX-2,通过生理生化特征、菌体形态观察及16S rRNA基因序列分析,鉴定菌株HX-2属于红球菌属(Rhodococcus),该菌株可耐受的最高盐度(Na Cl)和柴油浓度分别为10%和8 000 mg/L。菌株生长及降解的最适p H和温度分别为7. 0和25℃,在盐度为5%以内、p H为7. 0、温度为25℃、菌种投加量为2%的条件下,初始浓度为4 000 mg/L的柴油经4 d降解后,去除率均超过50%以上,且盐度为10%仍有10. 3%的降解率。对其耐盐机制进行分析表明细胞内相容性物质(甜菜碱)的含量随着盐浓度的增加而增大,说明甜菜碱的积累是菌株抵抗高盐浓度的主要机制。通过外源添加甜菜碱可以改善菌株在高盐条件下的生长情况并提高柴油降解率。因此,菌株HX-2是一株在盐渍化烃类污染修复方面极具应用潜力的烃降解菌。     

添加混合菌剂对石油污染土壤的降解

从甘肃华庆油田污染严重的土壤中富集培养、筛选分离得到A6,A5,D4,F1和F2共5种菌属的降解石油菌,在实验条件下向土壤中添加上述5种菌不同浓度的混合菌剂,并对土壤中的脱氢酶活性、土壤溶液电导率、氮磷的变化对石油污染土壤的降解率的影响进行研究.研究结果表明:当土壤中石油含量为50 g/kg时,加入高效降解菌的石油降解率比没有加菌剂的降解效率高,添加2％,4％和8％菌剂48 d的降解率分别为68.01％,80.42％和78.47％,均大于CK(没有任何组分)的降解率45.50％,4种处理中4％菌剂的修复效果最显著.添加的有机肥中氮和磷的含量是影响石油降解率的主要因素,只有加适量的有机肥如4％才能使降解效果最好.混合菌株降解石油表现出先降解高碳数正构烷烃为低碳数正构烷烃,高碳数正构烷烃中奇数碳向偶数碳正构烷烃演化的规律;原油中类异戊二烯烷烃在混合菌7d的作用过程中发生明显降解,菌株能较好地促使五环三萜类化合物立体构型中不稳定构型向稳定性构型转化的演化规律.     

高效石油降解菌株的筛选及菌群的构建

从海南澄迈油井周围污染的土壤中采集样品,以原油为唯一碳源,经初筛、复筛得到13株具降解石油性能的微生物,其中J-2、J-4、J-12、J-13菌株在培养10 d后,其石油降解率分别可达到27.92%、37.36%、30.98%和14.10%.选择这4株菌进行2株菌、3株菌、4株菌的混合培养,构建了11个降解石油的微生物体系,研究发现J-2与J-4混合菌群降解效果最好,高达71.58%,明显优于其他的混合菌群体系和单菌株的降解效果.根据形态学观察和生理生化特征对这4种菌株进行鉴定,初步确定为粉红头孢霉属(Cephaesosp),青霉属(Penicillium),链霉菌属(Streptomyces)和黄单胞菌属(Xanthomonas).     

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.     

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     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the     

An affordable accurate evaluation of the binding conformations predicted by molecular docking studies in bio-system

Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of     

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

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