维生素对微生物絮凝剂REA-11合成的影响

考察了生物素、维生素B1、维生素B12等维生素对谷氨酸棒杆菌生长及生物絮凝剂合成的影响.结果表明,培养基中添加生物素对菌体的生长无明显影响,0.2 mg/L的生物素对絮凝剂的合成有一定的促进作用;维生素B1对菌体的生长有轻微的促进作用,但对絮凝剂的合成无明显影响;维生素B12对菌体的生长有一定的促进作用,0.1 mg/L的维生素B12对絮凝剂的合成有轻微的促进作用,随着维生素B12浓度的增加开始对絮凝剂的合成产生抑制作用.     

甜菜碱、胆碱和蛋氨酸的营养作用及其在代谢中的相互关系

在动物营养学上,胆碱、甜菜碱归属于维生素和维生素的前体物质,蛋氨酸是机体蛋白质合成所必需的氨基酸。本文旨在阐明上述三种物质各自营养作用及在甲基代谢过程中的相互关系,并对它们在生产实践中的合理添加使用和相互替代的效果的研究情况作一综述。     

5，6-二甲基苯并咪唑（DMB）对丙酸杆菌生长及合成脱氧腺苷钴胺素的影响

在丙酸杆菌(Propionibacterium freudenreichii)厌氧发酵生产脱氧腺苷钴胺素(deoxyadenosylcobalamin,简称ADO)的过程中,中间体腺苷钴啉醇酰胺(adenosylcobinamide,简称CBI)和5,6-二甲基苯并咪唑(DMB)结合后生成产物ADO。目前维生素B12脱氧腺苷钴胺素发酵过程中的实时在线检测方法相对匮乏,为了解决该问题,提高维生素B12的发酵单位,以CBI为目标,运用代谢调控方法改善DMB的加入时间,研究不同时间加入DMB对丙酸杆菌生长以及ADO合成的影响。在分批次发酵情况下,实时检测了菌体发酵过程中具体的CBI合成量、ADO产量,并进一步绘制了菌体的生长曲线。结果表明,DMB对丙酸杆菌生长的抑制作用并不明显,但是可以抑制单位菌体产量,发酵周期为120h,最佳添加时间为90～100h,相比60h添加DMB可提高发酵单位59.08%。方法简便、快捷、高效,对维生素B12的发酵调控研究具有一定的参考价值。     

微生物法测定功能性饮料中维生素B12含量研究

该文建立了测定功能性饮料中维生素B12含量的微生物法.参考食品安全国家标准GB 5413.14—2010婴幼儿食品和乳品中维生素B12的测定方法，利用莱士曼氏乳酸杆菌生长速率与B12浓度的线性关系，制备标准曲线，根据标准曲线计算样品中B12的含量.根据功能性饮料与奶粉基底不同，对国标法中样品处理进行优化改良，同时实验中进行了加标回收对实验过程进行质量控制，并使用试剂盒法对测定结果进行比对.该方法操作简便，灵敏性及准确性高，可适用于功能性饮料中维生素B12含量的检测.     

前体氨基酸对维生素B_(12)发酵合成的影响

谷氨酸、苏氨酸、甘氨酸和甲硫氨酸是维生素B12合成的重要前体。在脱氮假单胞菌(Pseudomonas denitrifican)发酵的产物合成期以补加的方式考察了这4种氨基酸对维生素B12合成的影响。在合成培养基的基础上,通过单因素添加试验分别考察了这些氨基酸对维生素B12合成的影响,发现谷氨酸、甘氨酸和苏氨酸影响显著;并进一步利用三因素三水平的正交试验设计考察了氨基酸混合添加对菌体生长和维生素B12合成的影响,结果表明谷氨酸是最主要的影响因素,并且发现同时添加多种氨基酸更有利。当添加量为谷氨酸0.45 g/L、苏氨酸0.20 g/L、甘氨酸0.15g/L时,得到的菌体量和维生素B12产量分别比对照组提高了13.1%和46.0%。     

CO_2对脱氮假单胞菌发酵生产维生素B_(12)的影响

通过调整进气中空气和CO2的比例,研究了CO2的体积分数(φCO2)为0.03%,3.32%,8.86%和13.84%时对脱氮假单胞菌的生长和维生素B12合成代谢的影响。发酵过程的生理代谢分析结果表明:当进气中CO2体积分数增加到8.86%时,菌体的生长没有受到显著影响;而单位菌体糖消耗速率为29.95 mg/(g.h),仅为对照组的77%;产物的合成速率可达到1.75 mg/(L.h),比对照组1.02 mg/(L.h)的合成速率提高了71.6%。但CO2体积分数为13.84%时,菌体生长、底物利用以及维生素B12的合成都将受到抑制,因此在生产过程中控制CO2的体积分数非常关键。     

甘蔗糖蜜发酵生产维生素B12的动力学模型

为明确甘蔗糖蜜发酵生产维生素B12的过程,在优化过的培养工艺基础上,以甘蔗糖蜜作为培养基,研究利用谢氏丙酸杆菌发酵生产维生素B12的动力学特性,通过利用Origin7.5软件对试验数据进行回归分析,采用Logistic方程、Luedeking-Piret方程和与Luedeking-Piret方程相似的基质消耗方程对发酵...     

球等鞭金藻3011的生长与其营养盐关系的研究

对球等鞭金藻(IsochrysisgalbanaParke)3011进行了N、P、Fe、维生素B1、B12等营养试验,通过单因子和正交试验表明:在4种不同氮源中,以NaNO3培养球等鞭金藻最佳,其最佳质量浓度为10g·m-3;2种磷源对球等鞭金藻的影响不显著;在3种铁源中,以FeCl3培养球等鞭金藻为最佳,其最佳质量浓度为0.1g·m-3;在维生素试验中,以维生素B10.1g·m-3和维生素B120.0005g·m-3混合使用最佳.培养液的较佳配方是在天然海水中加入NaNO3—N10g·m-3;NaH2PO4—P1g·m-3;FeCl3—Fe0.1g·m-3;维生素B10.1g·m-3和维生素B120.0005g·m-3.     

三种维生素对赤潮异弯藻增殖的影响研究

研究了3种维生素(VB1、VB12、VH)对赤潮异弯藻增增殖的影响,结果表明除了维生素H外,另2种维生素对该藻增殖均有显著促进作用,并存在交互作用;其最适增殖浓度为60μg·L-1维生素B1,0.4μg·L-1维生素B12。文中还对维生素影响微藻增殖的形式提出了新的推测。     

纳滤膜脱除高粘度两性表面活性剂中的盐

采用纳滤膜考察了操作压力、不同的料液浓度、流量改变和浓缩过程对两性表面活性剂N,N-二甲基十二烷基甜菜碱（BS-12）中盐的脱除和BS-12浓缩效果的影响。实验结果表明：在操作压力2.5MPa和料液流量为583L／h下,对30％BS-12稀释后的BS-12浓度144g／L和氯化钠浓度39.2g／L料液进行纳滤膜脱盐浓缩,BS-12的截留率达到95％以上,氯化钠除盐率90％以上,可获得含盐量低于1％的BS-12,因而具有实际应用价值。     

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.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

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.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

Jane Eyre——A Feminist In The 19th Century

In the 19th century the society was controlled by men, and women were just appendants of them, they had not any rights and freedom. But Jane was an exception, she showed some characteristics of early feminist. Jane showed her characteristics of feminism in three aspects: rebellion, equality, and independence. These characteristics were helpful to her success, and feminism is the only way out for women of that time.     

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-