溶剂热条件下钴微纳米颗粒的构筑习性

以乙酸钴为钴源,水合肼为还原剂,在不同表面活性剂下,溶剂热法制备出不同形貌的二维、三维钴微纳米颗粒。通过扫描电子显微镜（SEM）、X射线能量色散谱（EDS）和X射线衍射（XRD）对产物进行了表征。采用自制的2-十一烷基-1-二硫脲乙基咪唑啉季铵盐（SUDEI）为表面活性剂时,制备出直径400～600nm,厚度约100nm的六角盘状二维产物,采用其他表面活性剂只能制备出三维的花状钴。初步探讨了溶剂热条件下钴微纳米颗粒的构筑习性。     

低温固相合成形貌和晶相可控的CdS纳米晶

用表面活性剂为形貌控制剂,通过低温固相反应成功制备出具有不同晶相和形貌的CdS纳米晶.研究结果表明,在反应过程中,表面活性剂所形成的结构对最终纳米晶的形貌起着决定性的作用.若以表面活性剂聚氧乙烯9醚为形貌控制剂,则所制备的产物为立方晶系的β-CdS球形纳米粒子,纳米粒子的直径为5-15 nm;而用聚乙二醇400为形貌控制剂时,则所制备的产物为六方晶系的CdS纳米棒,纳米棒的直径为20-80 nm、长度为100-400 nm.用X射线粉末衍射和透射显微镜技术对所制备纳米晶的成分、晶相、形状和尺寸进行了表征分析.对不同形貌CdS纳米晶的形成机理作了深入的讨论,提出了CdS纳米棒的表面活性剂软模板诱导自组装生长机理.     

一维勃姆石纳米材料的无模板水热制备

采用水热合成方法,无需表面活性剂作为模板,制备出了一维纳米γ-AlOOH材料,并研究了水热反应时间和温度对产物形貌和结构的影响.利用X-射线衍射谱(XRD)、傅里叶变换红外光谱(FTIR)和高倍透射电子显微镜(HSTEM),对产物的结构和形貌进行了研究.结果显示,在反应温度为200℃、时间为20h时,得到了形貌为纳米棒状的产物一维纳米γ-AlOOH材料.产物直径为20nm左右,长度在100~200nm范围内,粒径均匀,分散良好.     

微波辅助多元醇法快速制备Ag纳米线的研究

采用微波辅助多元醇法,以乙二醇为溶剂和还原剂,PVP为表面活性剂,CuCl2为控制剂,快速制备Ag纳米线.在保持其他条件不变的情况下,考察了微波功率、反应时间对产物Ag纳米线的影响.利用扫描电子显微镜(SEM)、X射线衍射(XRD)和紫外-可见分析(UV-Vis),对Ag纳米线的形貌、结构及光学性能进行了分析表征.结果表明,Ag纳米线直径为100 nm左右,呈面心立方晶体结构;UV-Vis图谱显示,在380nm和350nm处出现了吸收峰.此外,对Ag纳米线的生长机理进行了探讨分析,得出控制剂CuCl2的加入对银纳米产物的形貌起了主导作用.     

水热合成VO_2(B)带状结构的生长机理研究

以V2O5和草酸为原料,水热合成了VO2(B)带状结构.采用XRD,SEM,TEM和HRTEM等技术对不同水热条件下所得产物进行了表征,根据不同反应条件下产物的结构和形貌推断了VO2(B)带状结构的生长机理.结果表明:在水热反应过程中,V2O5首先和草酸反应生成V6O13,随着水热反应时间的延长,V6O13继续和草酸反应生成VO2(B),且最初生成的VO2(B)为杂乱无章的片状堆积结构,随着水热反应时间的延长,片状结构逐渐转化为长度约为1μm,宽度约为100～200 nm的带状结构,其晶格条纹间距约为0.51 nm.     

CuO纳米晶的一步超声室温固相合成及表征

在室温条件和超声波作用下,通过固相化学反应一步合成了CuO纳米晶,用粉末X射线衍射（XRD）及电子衍射法（ED）分析了固相产物的物相,用透射电镜（TEM）观测粒子的大小、形貌、粒径及粒径分布．结果表明,产物为颗粒大小均匀、晶粒形貌为近似球形粒状,平均粒径约为20nm的纳米晶,产率为93．1％．改变反应物、反应物配比、掺入惰性物质、加入微量溶剂或表面活性剂、研磨不同的时间等固相反应条件对合成CuO纳米晶的晶粒形貌、粒度和粒径分布有一定影响．     

简易一锅法可控合成MnO2纳米带

在无模板无表面活性剂的情况下,以KMnO4、乙酸和去离子水为原料,通过一锅法水热合成MnO2纳米带,考察温度、反应时间、反应物浓度和酸用量对产物形貌的影响,并采用X线衍射仪(XRD)、透射电子显微镜(TEM)和场发射扫描电子显微镜(FESEM)对合成的纳米MnO2进行表征.结果表明:产物为单分散性的MnO2纳米带,长度为5 ～ 10 μm,平均宽度和厚度分别约为70 nm和20 nm.     

在表面活性剂辅助下优质氢氧化钕纳米线的合成和表征

具有50～100nm平均直径和长约10μm的单晶氢氧化钕纳米线,已经在大量的CTAB（十六烷基三甲基溴化铵）阳离子表面活性剂的协助下通过水热法控制纳米结构的演化成功地合成,在表面活化剂CTAB的辅助下,可控制纳米结构的演化．测量方法包括X射线衍射（XRD）、扫描电子显微镜（SEM）、透射电子显微镜（TEM）．借助这些手段,可表征产物的特性．     

pH 值对水热法制备 LaVO4：0．5％Eu3＋纳米粉体的影响

以NH4 VO3、LaCl3· nH2 O等为原料,采用水热法合成了铕掺杂LaVO4纳米粉体,通过X射线粉末衍射、扫描电子显微镜、荧光测试仪等对制备的粉体进行了表征,考察了不同水热体系pH值（4-13）对产物晶相、微观形貌及荧光性能的影响,探讨了LaVO4晶体的生长机理。结果表明：产物的微观形貌为纳米颗粒或纳米棒,pH值低于10时,产物为单斜相LaVO4纳米晶,荧光强度较低;当pH值为11-13时,产物为四方相和单斜相两相,表现出较强的荧光性。     

水热合成过程中VO_2(B)纳米带的结构变化

以V2O5和草酸的黄褐色悬浊液为前驱物水热合成VO2(B)纳米带,采用XRD技术研究水热条件对VO2(B)纳米带结构的影响。结果表明,在水热温度为180~190℃、水热时间为20~24h时,可以制备结晶良好的VO2(B)纳米带;随着水热温度的升高,VO2(B)纳米带的平均晶粒尺寸逐渐增大,晶格畸变度逐渐减小,且产物的择优生长趋势逐渐明显;水热反应初期,VO2(B)纳米带的平均晶粒尺寸增长较快,随着水热时间的延长,VO2(B)纳米带的晶粒生长趋于平衡,晶格畸变度逐渐减小并趋于平缓,且产物逐渐形成了一定的结晶取向。     

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