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—株G~-球形趋磁细菌的发现与表征 总被引:3,自引:0,他引:3
在玄武湖水域发现一株 G- 球形趋磁细菌 X W - 1 ,光学显微镜下观察,可见菌体在地磁场的作用下,快速北向游移,平均游动速率约为0 .14 m m/s ,该菌株对磁场的作用极其敏感.透射电镜观察显示,在每一菌体的细胞壁上镶嵌了12 颗左右的磁小体,磁小体的大小和形状均匀一致,每颗磁小体长约60n m ,宽40nm ,x 射线能谱测试分析表明,磁小体为铁的氧化物. 相似文献
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一株G^-球形趋磁细菌的发现与表征 总被引:2,自引:0,他引:2
在玄武湖水域发现一株G^-球形趋磁细菌XW-1,光学显微镜下观察,可见菌体在地磁场的作用下游移,平均游离速率久为0.14mm/s,该菌对磁场的作用极其敏感,管射电镜观察显示,在第五菌体的细胞直镶嵌了12颗左右的磁小体,磁小体的大小和形状均匀一致,每颗磁小体长约60nm,宽40nm,x射线能谱测试分析表明,磁小体为铁的氧化物。 相似文献
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趋磁细菌是一类能够在一定的磁场内按磁力线方向运动的细菌,菌体内含有磁性颗粒,称磁小体.磁小体具有重要的应用价值.目前,对趋磁细菌的开发和利用主要是在磁性记录材料、分离技术和医疗卫生等方面. 相似文献
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趋磁细菌是一类能够在一定的磁场内按磁力线方向运动的细菌,菌体内含有磁性颗粒,称磁小体.磁小体具有重要的应用价值.目前,对趋磁细菌的开发和利用主要是在磁性记录材料、分离技术和医疗卫生等方面. 相似文献
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磁小体是磁靶向给药领域的研究热点,为了精准示踪生物体内的磁小体来指导靶向,基于磁小体和量子点构建一种新型磁光载体.利用静置培养和磁吸附的方法收集富含磁小体的趋磁细菌AMB-1,并通过超声破碎及磁吸附方法提取长度为5~10个的磁小体链,运用点击化学反应将含有羧基的CdTe/CdS量子点修饰到磁小体膜上,并利用人肝癌细胞HepG2初步开展光示踪有效性的验证.结果发现该载体可以成功地被细胞摄取,并在细胞内观测到磁小体的分布.笔者成功地研制出磁光载体,为后续的磁靶向给药、磁靶向热疗及荧光一体化的研究及应用提供了坚实的基础. 相似文献
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为了更清楚的了解趋磁螺菌产磁小体的合成机理和调节途径,用Tn5转座子诱变的方法筛选得到了2株磁小体合成降低的突变株,并克隆了突变株中被插入失活的基因,分别为编码ABC型Fe3+转移系统中的离子结合蛋白的amb3385基因和功能未知的锄b3672基因.互补实验表明携带amb3385和amb3672基因的广宿主载体可以不同程度地恢复突变株中磁小体的合成,证明了D.schuler关于磁小体合成假说的第一个步骤,即Fe3+从胞外向经由Fe3+转运蛋白运输至了胞内.由于amb3672基因比对时未发现特殊相似基因,其功能尚需进一步研究. 相似文献
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为了更清楚的了解趋磁螺菌产磁小体的合成机理和调节途径,用Tn5转座子诱变的方法筛选得到了2株磁小体合成降低的突变株,并克隆了突变株中被插入失活的基因,分别为编码ABC型Fe3+转移系统中的离子结合蛋白的amb3385基因和功能未知的amb3672基因.互补实验表明携带amb3385和amb3672基因的广宿主载体可以不同程度地恢复突变株中磁小体的合成,证明了D.Schüler关于磁小体合成假说的第一个步骤,即Fe3+从胞外向经由Fe3+转运蛋白运输至了胞内.由于amb3672基因比对时未发现特殊相似基因,其功能尚需进一步研究. 相似文献
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趋磁细胞研究:I.武昌东湖水体中趋磁细胞WD—1的分离 总被引:17,自引:2,他引:17
武昌东湖水域中存在杆状,螺旋状和旺状等不同形态的趋磁细胞,通常在细胞内有2~10个数量不等的磁小体,在微好氧条件下利用半固体培养基分离到一株G^-,短杆状的趋磁细胞WD-1,能谱电镜分析表明,该菌磁小体的元素组成是Fe,Al,Zn,Ga,P和S,共含量分别占84,57%,3.98%,2.75%、2.21%、1.12%和0.93%。 相似文献
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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. 相似文献
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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. 相似文献
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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. 相似文献
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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. 相似文献
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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。 相似文献
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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. 相似文献
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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. 相似文献
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Miao Maosheng 《华南师范大学学报(自然科学版)》2014,(6)
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- 相似文献
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Yang Weitao 《华南师范大学学报(自然科学版)》2014,46(6):137-138
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- 相似文献
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Bernard Kirtman 《华南师范大学学报(自然科学版)》2014,(6)
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 相似文献