耐高铀浓度氧化亚铁硫杆菌的驯化及其反应动力学

氧化亚铁硫杆菌在高铀浓度条件下的活性是微生物浸铀技术能否取得成功的关键所在,高浓度铀对细菌有明显的抑制作用,但驯化后可以降低及弱化这种抑制作用.通过考察不同铀浓度对氧化亚铁硫杆菌活性的影响,得出其最佳培养条件并对驯化后菌种对铁的氧化动力学进行了研究,结果表明,该菌在优化条件下培养72 h后,对数期的细菌比生长速率为0.032 2 h-1.     

黄铁矿强化生物浸出低品位磷矿

进行了嗜酸氧化亚铁硫杆菌、嗜酸氧化硫硫杆菌与嗜酸氧化亚铁钩端螺旋菌的混合菌强化浸出低品位磷矿的实验研究.结果表明:由于试样中硫含量低,不利于该磷矿的生物浸出.提出了在浸矿体系中添加黄铁矿来强化浸出的措施.考察了细菌种类、磷矿与黄铁矿配比以及初始Fe2+质量浓度等参数对磷浸出率的影响.采用驯化菌浸出该磷矿,能获得最佳的浸出效果,其适宜的工艺参数为初始Fe2+质量浓度9g.L-1、磷矿与黄铁矿质量比1:2.5,经过20d浸出,磷的浸出率可达95%.     

一株新的氧化亚铁硫杆菌菌株的筛选及其生长特性的研究

从湖南某矿的中性矿坑水中筛选出一株氧化亚铁硫杆菌菌株，以Fe^2＋的氧化为表征，研究了温度、pH值、Fe^2＋初始浓度、接种量对其生长特性和活性的影响．试验结果表明这株氧化亚铁硫杆菌菌株的最佳生长条件为：温度30℃左右，初始pH为2．0左右，Fe^2＋初始浓度为4．36g／L，接种量为10％．     

隐藏嗜酸菌DX1-1和氧化亚铁硫杆菌CMS的紫外诱变育种及浸矿研究

对从江西大兴黄铜矿的酸性矿坑水中分离得到的氧化亚铁硫杆菌CMS和隐藏嗜酸菌DX1-1进行紫外诱变育种及浸矿研究。结果表明:细菌CMS和DX1-1的最适生长温度为30℃,最适pH值分别为2.0和3.5;通过紫外诱变获得突变型隐藏嗜酸菌DX1-1和氧化亚铁硫杆菌CMS,最佳处理时间为60s,正突变率分别可达到16.7%和20.0%;诱变后的隐藏嗜酸菌DX1-1达到稳定期的时间比诱变前缩短20h,并且具有更大的菌体浓度;诱变后的氧化亚铁硫杆菌CMS氧化全部亚铁所需时间为48h,比诱变前菌株缩短11h;诱变后混合菌浸矿中,用原子吸收光谱法测定浸出30d后铜离子质量浓度达到2.78g/L,而紫外诱变前菌株浸出铜离子质量浓度为2.48g/L;生物浸出30d后,隐藏嗜酸菌DX1-1与氧化亚铁硫杆菌CMS的菌落个数比由1-1变为1-20左右。     

混合嗜酸硫杆菌浸出低品位磷矿的正交实验研究

以某矿酸性矿土中分离的嗜酸氧化亚铁硫杆菌和嗜酸氧化硫硫杆菌形成的混合菌为浸磷菌种、黄铁矿为能源物质、无磷无铁9K培养基为浸矿培养基,对混合菌浸出低品位磷矿石(w(P2O5)为22.8%)的浸磷条件进行了单因素优化和正交实验研究.结果表明,最优浸磷的适宜条件是,矿浆浓度为15 g/L,菌种体积浓度为15%,初始pH值为1.5,磷的浸出率为51.07%.     

Triton X-100对氧化亚铁硫杆菌氧化活性及浸出黄铜矿的影响

为提高黄铜矿的微生物浸出效果,研究了非离子表面活性剂Triton X-100对氧化亚铁硫杆菌(Acidithiobacillus ferrooxidans)氧化Fe2+和S0的活性以及浸出黄铜矿的影响,并采用XRD对浸出后的产物进行了表征.结果表明,Triton X-100对氧化亚铁硫杆菌氧化Fe2+有一定的抑制作用,而对氧化S0则显现出促进作用;Triton X-100可显著改善黄铜矿的微生物浸出效果,当其质量浓度为30 mg·L-1时,黄铜矿中铜的浸出率提高了52.15%.Triton X-100的加入提高了氧化亚铁硫杆菌对黄铜矿浸出过程中间产物硫的生物利用性和消解作用,从而提高了浸出体系中细菌浓度和Fe3+浓度,进而促进了黄铜矿的溶解.     

微生物浸出深海多金属结核中有价金属

对氧化亚铁硫杆菌浸出深海多金属结核中有价金属的可行性进行了,着重研究了矿浆浓度、接种量、温度、浸出过程中ＰＨ值对结核中有价金属钴和镍浸出率的影响,同时对氧化亚铁硫杆菌进行了驯化。实验表明,采用Ｌｅａｔｈｅｎ培养基,加入适量黄铁矿作为菌种的营养基质和浸出过程中的还原剂、多金属结核,在常温、酸性环境下,可直接浸出金属铜、钴、镍、锰和铁。     

有机碳源对氧化亚铁硫杆菌生长的影响

氧化亚铁硫杆菌为化能自养菌，嗜酸，通常生长于无机环境中。为了扩大其在有机环境中的应用，选择乙酸、丙酸和正丁酸三种低分子有机酸及葡萄糖作为氧化亚铁硫杆菌生之的有机环境，研究其在不同浓度不同有机物下的生长活性。实验结果显示：氧化亚铁硫杆菌在100mg／L低浓度的乙酸和400mg/L葡萄糖浓度范围内均能很好的生长，而在余下的几种有机物中生长则受到抑制。表明氧化亚铁硫杆菌并不是对所有的有机物都敏感，通过筛选和驯化能得到在有机环境中生长良好的菌株。     

应用表面活性剂进行低渗透砂岩铀矿床地浸采铀的实验研究

低渗透砂岩铀矿床的地浸开采是目前的一个技术难题.以新疆某铀矿为对象,利用搅拌浸出和柱浸实验研究了表面活性剂在低渗透铀矿地浸开采中的应用.实验中采用10 g/LH2SO4溶液作溶浸剂,并加入不同量的表面活性剂P.搅拌浸出实验结果表明,溶浸液中加入不同浓度的表面活性剂均可提高铀浸出率,在表面活性剂P的浓度为10 mg/L时其铀浸出率最高,达到92.6%.柱浸实验表明,加入10 mg/L表面活性剂P时矿石渗透系数可提高28.8%,铀的浸出率可提高32%而达到85.79%.表面活性剂降低溶浸液的表面张力,促进了铀的溶解和提高铀浸出率.低渗透砂岩铀矿床可以在溶浸液中加入适当的表面活性剂进行地浸开采.     

地浸采铀中珠形微生物氧化剂研究

采用生物细胞固定化技术将氧化亚铁硫杆菌制备成珠形微生物氧化剂.其特性为:氧化亚铁硫杆菌在珠体内浓度达每毫升4×1010个细胞,珠体直径0.5～2.5mm,珠体上的平均孔径8.0×10-9 m.用其在固定化细胞流化床反应器中处理模拟地浸吸附尾液,可将其中的Fe2 离子氧化为Fe3 离子,氧化-还原电位从310 mV提高到550 mV,调整酸度后即可用于浸出.珠形微生物氧化剂是酸法地浸采铀工艺中很有发展前途的新型氧化剂.     

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