血清浓度对MDCK细胞低密度培养的影响研究

目的:确定血清浓度对犬肾细胞(MDCK)培养的影响.方法:在DMEM培养基中添加了2%、5%、8%、10%的新生牛血清,以10个/cm2密度接种MDCK细胞培养后通过细胞集落计数,计算贴壁率.结果:不同血清浓度培养MDCK细胞均能形成明显的细胞集落,贴壁率分别为23.15%、43.17%、61.00%、74.89%.结论:血清浓度对MDCK细胞集落的形成及细胞贴壁率有明显的影响,8%和10%血清的贴壁率较高,适合该细胞培养.     

二苯并噻吩生物降解菌培养和反应条件的优化

考察了培养温度、时间、pH值对根癌土壤杆菌UP-3生长的影响,选择了最合适的培养条件.通过考察底物浓度、反应温度和反应时间对菌株UP-3降解二苯并噻吩(DBT)性能的影响,优化了生物降解的反应条件.结果表明:UP-3最佳培养条件为培养温度31℃,培养时间30 h,培养基pH值7.3;UP-3催化降解DBT反应的适宜条件为DBT质量浓度500 mg/L,反应温度31℃,反应时间35 h;适宜条件下UP-3生长细胞对DBT的降解率达到85%,说明其具有较好的应用潜力.     

大气中痕量氯的化学发光分析

本文利用鲁米诺与次氯酸根的化学发光反应,对空气中痕量氯的测定进行了全面、系统的研究;选定了最佳实验条件,在该条件下,4×10~(-8)g—5×10~(-7)g/ml 范围的次氯酸根浓度有良好线性关系。拟定了对空气中痕量氯的测定手续,用0.1N 氢氧化钠吸收空气中痕量氯,使其转变成为次氯酸根;在 pH 为10.0的介质条件下,用自制的流动注射式化学发光分析仪对空气及实验室实际环境进行了取样分析。方法简单、快速、灵敏、干扰少、准确度高。检出下限为1.8×10~(-8)g/ml,0.165ppm 试样测定,变异系数为±3%。     

牛肾原代细胞培养最适接种浓度的选择

为了提高口服轮状病毒活疫苗（LLR株）生产用原代牛肾细胞的产量和质量,对不同接种浓度培养的原代牛肾细胞的生长情况进行研究。将牛肾细胞按5×10^4、10×10^4、15×10^4、20×10^4、25×10^4、30×10^4个细胞/cm26个不同浓度接种到细胞培养瓶中,37℃培养,观察细胞生长情况并记录形成良好单层的时间。结果显示,接种浓度为20-30×10^4个细胞/c？的原代牛肾细胞培养8-9d时就能形成良好单层;而接种浓度小于20×10^4个细胞/cm2时,需11-12d才能形成良好单层或不能形成单层。说明在大批量培养原代牛肾细胞时,选择细胞接种浓度20-30×10^4个细胞/cm^2比较适宜。     

大蒜油工艺条件优化及其抑制嗜酸乳杆菌体外实验研究

目的：以蒸馏提取法为基础,对大蒜油工艺条件的进行优化;用实验产物大蒜油进行嗜酸乳杆菌体外抑菌试验。方法：进行四因素三水平的正交实验,由此确定提取最佳工艺条件组合;以平板培养法测定大蒜油对嗜酸乳杆菌的最小抑菌浓度。结果：由正交实验确定最佳工艺条件组合为：发酵温度40℃;发酵时间150min;发酵pH值6.0;料液比1：3;经重复性试验证明该工艺条件组合能够稳定地将出油率控制在0.136%,接近相关文献报道结果。大蒜油对嗜酸乳杆菌的最小抑菌浓度为1.36×10^-5mg/ml。结论：蒸馏法可作为提取大蒜油的简便、稳定、可靠的方法。大蒜油对嗜酸乳杆菌有抑制作用。     

嗜水气单胞菌发酵条件的优化研究

研究了嗜水气单胞菌的最佳培养条件,通过单因子实验得到该菌株的最佳碳源为葡萄糖,最佳氮源为大豆蛋白胨,初始pH值为7.5,最适生长温度和时间为28℃、36h,最佳氯化钠浓度为6.84mg/mL;在其他培养条件不变的情况下,通过对大豆蛋白胨、葡萄糖、K2HPO4浓度、初始pH值做四因子三水平的正交实验,得到培养基最佳组合为:葡萄糖10 g/L、大豆蛋白胨10 g/L、K2HPO44.56mg/mL、初始pH值7.5.研究结果为嗜水气单胞菌规模化发酵培养奠定了基础.     

几种单细胞藻饵料对卤虫早期生长的影响

本文报道了作为饵料的盐藻、湛江又鞭金藻、三角褐指藻与卤虫早期生长的关系。结果表明:用盐藻喂养早期卤虫,最佳藻液浓度为2.5×10~6个/ml,用湛江叉鞭金藻喂养,其最佳藻液浓度为5×10~6个/ml,用三角褐指藻喂养,其最佳藻液浓度亦为5×10~5个/ml。对三者进行比较,以投喂湛江叉鞭金藻的早期卤虫的成长速度最快。     

辅酶Q_(10)酸热破碎法提取工艺条件的研究

为了研究酸热法提取辅酶Q10的最佳工艺条件,系统研究了酸的种类,破壁温度,酸的浓度,酸的添加量,破壁时间等因素对辅酶Q10提取效果的影响.结果表明,酸热法提取辅酶Q10的最佳工艺条件为:盐酸浓度3 mol/L,盐酸的添加量10 ml/g(干菌),破壁温度90℃,破壁时间25 min.     

光照对考马斯亮蓝法测定蛋白质浓度影响的研究

通过考马斯亮蓝法测定在不同光照和孵育时间下对已知不同浓度的牛血清蛋白的影响.结果显示,在0~100μg/ml蛋白质浓度标准曲线测定范围内,黑暗环境测定蛋白质误差率最小.在黑暗和弱光条件下高浓度蛋白质组(50~75μg/ml)误差率最低显著低于低浓度蛋白质组(5~25μg/ml).在黑暗和弱光条件下浓度在50~75μg/ml范围内的蛋白质与染料孵育30 min以内时误差率较低且较稳定.因此,采用考马斯亮蓝法测定蛋白质浓度时,环境光照、待测样品浓度以及染料与蛋白质孵育时间等是决定实验结果准确性的重要因子.     

实验动物金黄色葡萄球菌LAMP法快速检测

目的建立一种灵敏、高效,可用于实验动物金黄色葡萄球菌检测的环介导等温扩增技术(Loop-mediated isothermal amplification,LAMP)。方法针对金黄色葡萄球菌nuc基因(V01281.1)参考设计4条LAMP扩增引物,并选取常见实验动物致病菌进行引物特异性检测;通过优化LAMP反应体系中Mg~(2+)浓度、dNTPs浓度及LAMP反应时间,确立LAMP反应最佳条件;本文采用LAMP法和PCR法对不同浓度梯度的金黄色葡萄球菌以及用不同浓度金黄色葡萄球菌人工感染的粪样进行检测,比较两种方法的检测灵敏度。结果通过条件优化,本实验建立的LAMP法检测实验动物金黄色葡萄球菌的最佳反应温度为60℃,反应时间为50 min,优化后的LAMP反应体系为dNTP浓度2.0 mmol/L、Mg~(2+)浓度8.0 mmol/L、引物对FIP/BIP浓度1.6μmol/L、引物对F3/B3浓度0.2μmol/L,且与其它常见实验动物致病菌无交叉反应;对金葡菌纯培养物进行检测,LAMP法检测灵敏度为9CFU/反应管(9×10~3CFU/mL),PCR法检测灵敏度为9×10~1CFU/反应管(9×10~4CFU/mL),对人工接种金黄色葡萄球菌的SD大鼠粪样进行检测,LAMP法检测灵敏度为4.49×10~4CFU/0.1 g粪样,PCR法检测灵敏度为4.49×10~5CFU/0.1 g粪样。结论本实验建立的实验动物金黄色葡萄球菌LAMP检测方法,与PCR法,免疫学法和传统检测方法比较,具有特异性强、灵敏度高、操作简单等特点,可应用于实验动物金黄色葡萄球菌的快速检测。     

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.     

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