硫化铋纳米棒的制备及性能研究

采用水热法以Bi(NO3)3.5H2O为铋源、CH3CSNH2为硫源、尿素为矿化剂在丙三醇与水的混合溶剂中合成较小尺寸的Bi2S3纳米棒,采用X射线粉末衍射(XRD)、扫描电子显微镜(SEM)、高分辨透射电子显微镜(HRTEM)、紫外-可见分光光度计(UV-Vis-NIR)、荧光分光光度计(PL)等对样品进行检测表征.结果表明:制备的Bi2S3为纯相正交结构,形貌和尺寸受到S与Bi的比例、溶剂种类、反应温度和反应时间等因素影响.通过控制不同的条件可得到形貌均一的纳米棒.并对小尺寸Bi2S3纳米棒的光学性能及生长过程进行了初步讨论.     

CdS纳米棒的合成及硫源的影响

溶剂热法合成CdS纳米棒,分别考察了反应介质尤其是硫源对CdS生成的影响.采用X射线衍射(XRD)、扫描电子显微镜(SEM)、紫外-可见吸收光谱(UV-Vis)等对合成的CdS纳米棒的形貌和结构进行分析、表征.结果表明,以乙二胺为溶剂可以合成出CdS纳米棒,不同硫源合成的CdS纳米棒长度明显不同,这可能与硫源的水解释放S2-机理有关.     

硫化铋纳米晶的水热合成及表征

在低温水热条件下,以BiCl3、Na2S2O3(或Na2S、硫脲)为反应物,制备了硫化铋(Bi2S3)纳米晶.用X射线粉末衍射(XRD)、扫描电镜(SEM)及纳米粒度测定仪对样品的结构及形貌进行了表征分析.结果表明,所得样品为正交晶系的Bi2S3纳米晶,形貌主要为纳米棒;同时硫源、反应温度及反应时间会影响样品的粒径.     

锐钛矿TiO_2纳米片的可控合成和光催化机制（英文）

采用溶剂热法合成了锐钛矿TiO_2纳米结构,研究乙醇、乙二醇和丙三醇对TiO_2形貌和光催化性能的影响.采用X射线衍射仪(XRD)、扫描电子显微镜(SEM)、拉曼光谱(Raman)、紫外可见近红外分光光度计(UV-Vis)等对此TiO_2样品进行表征.结果表明:随着黏度的增加,TiO_2的形貌由纳米片到纳米棒最后形成纳米颗粒;在乙醇溶液中合成的TiO_2纳米片表现出优异的光催化性能,这是由于UV光具有粒子性,光的多次反弹使得样品具有高的紫外吸收所致.     

CaGd3F11:Eu3+超小纳米晶的制备及其发光性质研究

以无水氯化钙、稀土硝酸盐、正辛醇为原料,以正辛胺和油酸为表面活性剂,通过控制不同的反应条件,采用溶剂热法制备出形貌均匀的CaGd_3F_(11):Eu~(3+)纳米发光材料.用X射线衍射(XRD)、透射电子显微镜(TEM)和荧光分光光度计对合成的纳米晶的粒径、形貌和光学性质进行了表征.结果表明CaGd3F11纳米晶的结晶度良好且尺寸均匀(约5nm),其作为基质材料,掺杂Eu3+表现出很强的荧光发射.     

Bi2S3纳米棒的可控合成和表征

采用水热法,以Bi(NO3)3·5H2O和Na2S·9H2O为前驱体,通过不同的反应条件合成出不同形貌的Bi2S3纳米棒.所得产物用XRD和TEM进行了分析和表征.结果表明,当Na2S·9H2O与Bi(NO3)3·5H2O的摩尔比为2∶1,水热合成温度为l50℃,前处理模式为超声振荡时,所得Bi2S3纳米棒结晶度较高,...     

Cu_2ZnSnS_4纳米晶的合成和表征

用乙酰丙酮铜、二水醋酸锌、氯化亚锡和高纯硫分别作为反应的铜源、锌源、锡源和硫源,油胺充当反应溶剂和活性剂,采用热注入法在不同的温度和反应时间下合成出了Cu_2ZnSnS_4纳米晶体.然后,使用X射线衍射、紫外-可见分光光度计、扫描电子显微镜和透射电子显微镜等手段分别对Cu_2ZnSnS_4纳米晶体的晶格结构、吸收谱线和表面形貌进行了表征.通过对比发现,在270℃时合成出的纳米晶体比较纯净,纳米晶体颗粒的尺寸在一定反应时间内随反应时间的延长而增大.得到的产物在有机溶剂甲苯中分散性良好.这样的"墨汁"溶液在后期制备薄膜太阳能电池更有利.     

溶剂热法制备织构化Bi0.5Na0.5TiO3陶瓷的影响因素

以Bi(NO3)3.5H2O和Ti片为原料,无水乙醇为溶剂,采用溶剂热法合成了具有取向性的织构化Bi0.5 Na0.5 TiO3(BNT)无铅压电陶瓷.采用X射线衍射(XRD)、场发射扫描电子显微镜(FE-SEM)和能谱仪(EDS)对BNT无铅压电陶瓷物相、显微形貌和成分进行了表征.系统研究了NaOH浓度、[Bi3+]浓度、表面活性剂和溶剂等因素对BNT晶粒物相、微观形貌和成分的影响.结果表明:NaOH浓度为1 mol.L-1,[Bi3+]浓度为0.1 mol.L-1,聚乙二醇(PEG)加入量为1～6 mL,且溶剂为无水乙醇时可以制备出织构化BNT陶瓷,产物颗粒尺寸平均为10～20μm.     

Cds量子点/过氧化酶纳米杂化功能材料的制备及分析应用

提出了以过氧化氢酶、Cd(NO3)2·4H2O和Na2S·9H2O为原料制备CdS量子点/过氧化氢酶纳米杂化功能材料的新方法,在室温条件下成功制备出了CdS量子点/过氧化氢酶纳米杂化功能材料; 讨论了nCd∶nS以及nCdS∶n过氧化氢酶对CdS量子点/过氧化氢酶纳米杂化功能材料的尺寸及荧光性质的影响.使用透射电子显微镜、紫外-可见分光光度计及荧光分光光度计等对纳米杂化功能材料进行了表征,对其分析应用进行了探讨.     

酸性水热合成CeO_2纳米颗粒的光学和磁学性质（英文）

以CeCl_3·7H_2O为铈源、NH3·H2O为矿化剂、HCl为酸性调节剂,利用水热法成功制备了二氧化铈纳米颗粒.采用X射线衍射仪(XRD)、扫描电子显微镜(SEM)、紫外-可见分光光度计(UV-Vis)、荧光分光光度计(PL)、拉曼光谱(Raman)和振动样品磁强计(VSM)等分析测试手段,对CeO_2纳米颗粒的晶相、形貌、光学和磁学性质进行了表征.XRD测试结果表明样品的晶格参数略高于块状CeO_2的,并随着pH值的增大而减小.所有样品的形貌均为球形.从紫外-可见吸收光谱中,估计出的样品直接带隙值小于块状CeO_2的,且此值随pH值的增加而增加.pH值为2时合成样品具有室温铁磁性,此性质的出现可能与Ce~(3+)和氧空位的存在有关.     

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.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

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.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

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-     

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-