不同培养条件对海洋尾丝虫种群增长的影响

为揭示海洋尾丝虫在不同培养条件下的种群动力学规律,初步探讨不同温度(4,12,20,28,32℃)及不同培养液条件(虾肉浸出液、麦粒浸出液、牛肉浸膏培养液和酵母浸膏培养液)对其种群增长的影响.结果显示,不同温度下,4℃时繁殖速度慢,经历长时间(9 d左右)的停滞期进入增长期;12℃时不同培养液中的最大种群密度表现为:酵母浸膏培养液牛肉浸膏培养液虾肉浸出液麦粒浸出液;20℃则表现为:牛肉浸膏培养液酵母浸膏培养液麦粒浸出液虾肉浸出液.结果表明,牛肉浸膏和酵母浸膏培养液适用于短期种群的快速扩大培养,虾肉及麦粒浸出液适用于实验室保种.20℃是海洋尾丝虫生长繁殖的最适温度,而12℃的虫体种群密度稳定期维持较久.研究结果提供了实验室培养和保存海洋尾丝虫的方法,并为海水养殖动物的海洋尾丝虫病研究提供了实验生态学数据.     

不同温度、pH值对草履虫Logistic增长实验效应的影响

对不同温度和pH值下草履虫种群增长的研究表明,温度对草履虫Logistic增长实验结果的影响较大,pH值在一定的范围内没有影响;最适宜的温度条件为22℃左右,最适宜的初始pH值为7。     

铜绿微囊藻对浮游动物生长繁殖的影响

分离并纯化培养草履虫、绿眼虫及枝角类的大型氵蚤等浮游动物 ,同时培养产毒铜绿微囊藻 .逐日观察、计数稳定期的铜绿微囊藻培养液在不同密度时对不同种类浮游动物生长繁殖的影响 .结果表明 :铜绿微囊藻对不同类别浮游动物的影响因藻类浓度变化而异 ,铜绿微囊藻对草履虫的抑制影响不明显 ;对绿眼虫的生长繁殖能较强抑制 ,当铜绿微囊藻的密度大于 9× 1 0 6 个 /L时 ,绿眼虫几乎无法生存 ;当铜绿微囊藻密度大于 9× 1 0 9个 /L时 ,对大型氵蚤表现出一定程度的抑制     

培养液对尾草履虫种群增长和个体形态的影响

目的 探讨培养液对尾草履虫种群增长和个体形态的影响，并筛选合适的尾草履虫培养液。方法 采用稻草、奶粉、酵母、杂粮4种培养液对尾草履虫进行培养。结果 杂粮培养液、稻草培养液和奶粉培养液里的草履虫生长繁殖的较快。结论 奶粉培养液的适宜浓度为0．2%；杂粮培养液的适宜浓度为4％。杂粮培养液培养的尾草履虫长度、宽度都比较大，个体宽短；稻草培养液培养的尾草履虫长度、宽度都比较小，个体细长。不同的培养液适合不同的培养用途。     

几种培养液对草履虫生长的影响

用八种不同的方法培养草履虫,结果表明,用未污染的天然水和未煮沸的稻草液作培养液均能培养出草履虫,实验结果还显示了不同培养方法对草履虫群体衰退情况的影响;并进一步探究了水质对草履虫生长的影响．     

重组毕赤酵母体系生成PlUGT1蛋白适宜条件研究

通过单因素试验分别研究pH值和温度对重组毕赤酵母GS115/pPIZA-PlUGT1生长以及甲醇浓度、pH值和温度对诱导表达PlUGT1蛋白的影响.结果表明,pH6.5和30 ℃是培养重组毕赤酵母GS115/pPIZA-PlUGT1最佳的生长条件,重组毕赤酵母GS115/pPIZA-PlUGT1诱导表达蛋白的适宜条件为甲醇体积分数0.5%、30 ℃和pH5.0,该条件下培养72 h,培养液中的蛋白质量浓度为0.721mg/mL.     

pH值对草履虫种群增长的影响

用群体累积培养法研究了pH值对草履虫(Paramecium caudatum)种群增长的影响。在酸性较强(pH为3.0和4. 0)的环境下草履虫均死亡。pH为4.0-10.0时草履虫均能正常生长。方差分析结果表明pH值对草履虫的密度和种群增长率均无显著影响(P>0.05)。草履虫对酸的耐受范围在5.0-7.0之间;而在弱碱性环境下,pH在8.0时草履虫的密度和种群增长率较大,并随着pH的增大而减小。     

金藻0898培养的生态条件研究

在实验室模拟条件下,研究了温度、光照、盐度、pH值和营养盐对金藻0898生长繁殖的影响,结果表明：金藻0898的适宜温度为10～35℃,最适温度为20～25℃;适宜照度为500～10000lx,最适照度为3500～10000lx;适宜盐度为5～70,最适盐度为30;适宜pH值为3～9,最适pH值为7～8．培养液的较佳配方是在天然海水中加入NaNO3-N10g·m^-3,NaH2PO4-Plg·m^-3,FeC6H5O7-Fe0．1g·m^-3,维生素B1 1g·m^-3和维生素B12 0．05g·m^-3．     

环境条件对微生物在滤料表面生长繁殖的影响

针对在适当的空气环境条件下,中央空调机组或大型客机环控系统中空气过滤器拦截的微生物可能在过滤器上大量生长繁殖的情况,挑选常用的玻璃纤维过滤材料,对其进行染菌,控制空气环境条件下培养,从而研究不同温湿度环境条件、滤料含水量以及不同滤料结构对微生物在滤料上生长繁殖的影响.结果表明:温度对含水滤料表面微生物最大生长繁殖量没有明显影响;在37,℃、90%相对湿度条件下的细菌最大生长繁殖量大约为加水滤料上的1/2,且大于相同温度下的低湿条件最大生长繁殖量;17,℃时,不同相对湿度条件下均没有生长趋势;低效滤料更适宜微生物生长.上述结论说明长期处于高湿度下的空气过滤器是最容易被微生物驻留并生长繁殖的部件,容易形成微生物二次污染.     

O／W型乳化液破乳茵发酵条件优化及破乳研究

以枯草芽孢杆菌全培养液对O/W型乳状液进行破乳效能研究.通过正交试验对枯草芽孢杆菌的发酵条件进行优化,以实现最优破乳效果.结果表明,培养温度25℃、摇床转数140 r/min、培养基pH值7.0、接菌量6%、培养时间24 h,枯草芽胞杆菌培养液中细菌生长量最高.相同培养条件,培养时间20 h,全培养液对模型乳状液的破乳效率最高,室温下48 h排油率100%.该破乳菌培养液具有良好抗酸能力及热稳定性.培养液pH值在中性及酸性范围内,枯草芽胞杆菌培养液排油率在60%以上.碱性增强至pH值为10培养液几乎丧失破乳能力.45～90℃热处理会使破乳剂破乳效率稍有降低,温度增至100℃破乳活性反而增加.100 mL O/W型原油废水中加入5 mL的枯草芽孢杆菌全培养液,30 min后排油量为62.056 mg/L,优于化学破乳剂.     

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