EDTA络合溶胶-凝胶法制备Ca3(VO4)2:Eu发光材料

以金属硝酸盐和EDTA为原料,用EDTA络合溶胶-凝胶法制备出Ca3(VO4)2:Eu发光材料,分别用FTIR、XRD、荧光分光光度计等手段对Ca3(VO4)2:Eu荧光粉进行表征,结果表明:仅在740℃焙烧即可得到颗粒细小,组分均匀,纯物相的Ca3(VO4)2:Eu发光材料.     

EDTA络合溶胶—凝胶法制备Ca3（VO4）2：Eu发光材料

以金属硝酸盐和EDTA为原料，用EDTA络合溶胶-凝胶法制备出Ca3（VO4）2：Eu发光材料，分别用FTIR、XRD、荧光分光光度计等手段对Ca3（VO4）2：Eu荧光粉进行表征，结果表明：仅在740℃焙烧即可得到颗粒细小，组分均匀，纯物相的Ca3（VO4）2：Eu发光材料。     

Ca3(VO4)2:Eu3+,Bi3+荧光材料的结构及性能研究

采用燃烧法工艺合成了Ca3(VO4)2:Eu3+荧光粉,对其结构、形貌和发光性能进行了表征,该荧光材料颗粒形貌规则、均一、发射主峰位于615.0nm,是一种良好的红色荧光粉.     

Ca3（VO4）2:Eu3+,Bi3+荧光材料的结构及性能研究

采用燃烧法工艺合成了Ca3(VO4)2:Eu3+,Bi3+荧光粉,对其结构、形貌和发光性能进行了表征,该荧光材料颗粒形貌规则、均一、发射主峰位于615.0nm,是一种良好的红色荧光粉。     

Ca3(VO4)2:Eu3+,Bi3+荧光材料的结构及性能研究

采用燃烧法工艺合成了Ca3(VO4)2:Eu3 ,Bi3 荧光粉,对其结构、形貌和发光性能进行了表征,该荧光材料颗粒形貌规则、均一、发射主峰位于615.0nm,是一种良好的红色荧光粉。     

A9Ln0.95Eu0.05（VO4）7(A=Mg2+,Ca2+,Sr2+,Ba2+;Ln=Y3+,La3+,Gd3+)的光致发光（英文）

用固相反应法制备A9Ln0.95Eu0.05(VO4)7(A=Mg2+,Ca2+,Sr2+,Ba2+;Ln=Y3+,La3+,Gd3+)样品,研究它们的光致发光性质.所有Eu3+掺杂的样品能被310 nm的近紫外光激发,它的特征发射峰是由于Eu3+的5D0-7F j(j=1,2,3,4)跃迁引起的.然而,对于Mg9Gd0.95Eu0.05(VO4)7样品,在450～800 nm波长范围内呈现出很宽的发射谱.Mg9Gd0.95Eu0.05(VO4)7的宽发射谱是VO43-的本质发射,源于Mg9Gd0.95Eu0.05(VO4)7样品中VO4四面体的严重晶格畸变.Mg9Gd0.95Eu0.05(VO4)7很宽的发射谱表明其在发光器件中有潜在应用价值.     

稀土长余辉发光材料M(Ca,Ba)OAl2O4:Eu2+,Dy3+的制备及性能研究

采用硼酸覆盖工艺在低温、还原气氛下制备了M(Ca,Ba)OAl2O4:Eu2 ,Dy3 长余辉发光材料.用X射线粉晶衍射对其进行了物相鉴定,表明在1175℃已得到纯相的M(Ca,Ba)OAl2O4产物.研究了产物的激发-发射光谱,激活剂Eu2 掺量和碱金属的比值以及激活剂Eu2 和Dy3 比值等条件对长余辉发光材料的相对发光强度的影响.结果表明:采用碳粉掩埋坩埚制造还原气氛.硼酸覆盖原料上方.灼烧温度为1175℃,恒温150min,随炉自然降温的生产工艺.可制备出发光性能优良的碱土铝酸盐长余辉发光材料.     

Dy~(3+)在Ca_(1-x)Sr_xS:Eu~(2+)Er~(3+)中的光致发光特性

研究加入Dr3+离子后的Ca1-xSrxS:Eu2+，Er3+的荧光激发光谱、发射光谱及余辉时间．结果表明，Ca1-xSrxS:Eu2+，Dy3+，Er3+是一种发光效率高、余辉时间长的红色发光材料．     

(Sr1-xCax)Al2O4:Eu发光材料的研究

以SrAl2O4:Eu发光材料为基础,通过对基质的部分修饰,合成了(Sr1-xCax)Al2O4:Eu磷光体,并利用XRD对其晶体结构进行了研究.结果表明,加入Ca后,原来在室温下稳定存在的属于单斜晶系的鳞石英结构SrAl2O4相逐渐变成六方晶系,证明了Ca有稳定六方相的作用.同时研究了该发光粉的发射光谱,并讨论了Ca的引入对发光性能的影响.     

Ca2BO3Cl:Eu2+,Nd3+的近红外发光与能量传递

用高温固相法制备Ca2BO3Cl：Eu2+,Nd3+近红外发光材料,并运用X线衍射、近红外发光光谱、激发光谱和发射光谱等手段对材料进行表征;研究Eu2+对Nd3+近红外发光性能的影响及相对强度变化的规律,探讨该体系中Eu2+对Nd3+的能量传递机理。研究结果表明：Eu2+的掺入可提高Nd3+的近红外发光强度,当Eu2+和Nd3+的掺杂量(质量分数)分别为3％和5％时,近红外发光最强;Eu2+通过无辐射传递方式向Nd3+有效地传递能量,对Nd3+近红外光有很好的敏化作用。     

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