石墨矿床中产出的天然纳米碳管

纳米碳管因其特有的性质已成为一种引人注目的材料。本文报道了产于新疆苏吉泉石墨矿床中的天然纳米碳管,并对其进行了高分辨电子显微镜研究。该发现表明迄今为止所有碳的同素异形体均可产于自然界,并且高温、压力、催化剂颗粒在产生纳米碳管的过程中起到了非常重要的作用。计算了石墨化花岗岩的形成温度和压力等条件。该发现对指导科学家合成纳米碳管和利用该矿床具有十分重要的意义。     

酸处理对多壁纳米碳管形态的影响

文中研究了酸处理对多壁纳米碳管形态的影响。分别用浓硝酸及浓硫酸和浓硝酸混合酸对未经石墨化多壁纳米碳管(MWCNTs)和石墨化多壁纳米碳管(MWGNTs)进行处理,讨论了不同处理时间,不同酸体系对不同碳管的处理效果,并采用TEM对其进行形态分析。结果发现,用硝酸长时间处理MWCNTs使纳米碳管发生短切,长径比变小,并且侧壁被整层剥离,管壁变薄;硝酸对MWGNTs的短切与剥离现象不明显。硝酸和硫酸的混合酸在0.5h内就可以将MWCNTs氧化殆尽,而使MWGNTs氧化殆尽则需要2h。在短切过程伴随着可以将多壁纳米碳管的管壁整层剥离的现象,用硝酸处理MWCNTs时该现象比较明显,处理MWGNTs时效果不明显;而混酸的氧化速度太快,处理两种多壁纳米碳管过程中的短切与剥离现象均不明显。     

碳包覆磁性金属纳米粒子的制备及表征

以含Fe，Co的SiO2气凝胶为催化剂，采用CVD法高温气相催化裂解甲烷的方法合成了碳包覆铁钴磁性纳米粒子，并用透射电子显微镜、X射线衍射仪等对材料的形貌、相结构进行了表征，采用振动样品磁强计对其静态磁性进行了测试。结果表明，碳包覆Fe／Co磁性纳米粒子，主要呈球形和椭球形，其包覆层为20层左右的石墨层，另有少量粒子被纳米碳管包覆，位于纳米碳管顶端。其饱和磁化强度Mo和矫顽力Hc分别为146．4kA／m和3468A／m。     

柴西北缘黄矿山一带晶质石墨矿地质特征及成因分析

为了探讨柴西北缘黄矿山一带晶质石墨矿的地质特征及成因,文中对黄矿山一带石墨矿床的矿床地质特征及成矿环境进行了综合分析,并对黄矿山一带石墨矿床从成矿地质条件以及成矿模式上进行了归纳总结。黄矿山一带石墨矿床产于下元古界达肯达坂群,大理岩和石英片岩为含矿岩性,经过区域变质作用以及动力变质及接触变质作用的叠加,最后形成晶质石墨矿石。综合分析认为黄矿山一带石墨矿床的成因类型为区域变质型,已发现的矿体规模大,走向延伸稳定,显示出较好的石墨矿找矿前景。     

碳管纳米弹簧快速建模与压缩特性有限元分析

给出了ANSYS有限元软件中碳管纳米弹簧的快速建模方法,对碳管纳米弹簧的轴向压缩进行了大变形有限元分析。为验证该方法与结果的有效性,还将一碳管纳米弹簧压缩刚度、临界失稳载荷的计算值与相应的试验结果、解析解进行了比较。研究表明,有限元结果与试验结果、解析解均较为接近,这说明碳管纳米弹簧的压缩特性分析是有效的;此外还发现,典型微米长度的碳管纳米弹簧的轴向压缩刚度为nN/nm量级,压缩失稳临界载荷为几十nN。     

竹节状纳米碳管的控制合成

通过对过程与工艺的合理设计,以二茂铁为催化剂、甲苯为碳源,在N2保护气氛中,通过分段程序升温均相共蒸发碳源与催化剂的混合溶液,实现了竹节状纳米碳管的一步催化合成.生成的竹节状纳米碳管相互缠绕少、离散程度高,外层管壁由连续的石墨片构成,内腔有曲率一致,但长度分布不等,厚度小于管壁的间隔层,管径均匀,直径约20～40 nm,具有较高的石墨化度,微晶尺寸约116 nm.研究还依据实验事实,对竹节状纳米碳管的生成机理进行了探讨.     

碳纳米管在轴向磁场中的电子态密度

研究了纳米碳管在接近轴向磁场中的Aharonov-Bohm效应，计算结果表明纳米碳管的电子态密度会被磁场剧烈地改变，所有的纳米碳管都会出现一个随穿过的磁通量周期化的能隙，周期为h/e，因此纳米碳管的导电性也随磁通周期地改变；但对不同类型（金属型和半导体型）的纳米碳管，这种变化的图样有不同的特征。     

纳米碳管的制备及应用前景

纳米碳管是一种重要的纳米材料和碳分子，其独特的分子结构和性能引起了人们的广泛关注。作者综述了纳米碳管的几种制备方法及潜在的应用前景。     

纳米碳管的性质及应用技术

从纳米碳管的分子结构，性质以及潜在的应用，对这种新型纳米材料作了简要描述；对纳米碳管分子结构与性质之间的联系及纳米碳管在半导体，场电子发射器，复合材料增强等方面的应用研究情况进行了介绍。     

氯化铁为前驱态催化剂的纳米碳管制备和表征

利用氯化铁为催化剂前驱体 ,结合悬浮催化剂法和基体法的优点 ,采用一种我们称之为悬浮催化 -基体的新方法在 70 0℃生长出了管壁清洁、直径均匀的纳米碳管 ,同时讨论了经不同时间氢气预处理的催化剂铁颗粒对生长纳米碳管直径和缺陷的影响 .实验显示该方法很有希望实现纳米碳管廉价、大批量生产     

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.     

橡胶颗粒沥青混合料低温抗裂性试验研究

以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.     

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-