原子簇Ni3BP异构体结构与稳定性的DFT研究

用DFT方法在B3LYP/Lanl2dz水平上对原子簇Ni3BP单重态和三重态的所有可能构型进行全参数优化,得到5个稳定构型:单重态3个,三重态2个;同时,也对各稳定构型之间的异构化进行了研究,得到.单、三重态势能面上与体系异构化相联系的4个过渡态.分析各异构体的相对稳定性及异构化过程得出:Ni3BP(3)(A′)是单、三重态中热力学最稳定的异构体;单重态的Ni3BP(1)(A)、Ni3BP(1)(B)和三重态的Ni3BP(3)(A′)、Ni3BP(3)(B′)具有一定的动力学稳定性.     

原子簇Ni2BP稳定结构与成键性质的DFT研究

用DFT方法在B3LYP/Lan12dz水平上对原子簇Ni2BP单重态和三重态的所有可能构型进行全参数优化,获得2个单重态、3个三重态共5个稳定构型;原子簇三重态的稳定性强于单重态,其中Cs对称性的Ni2BP[3](A)是所有单、三重态中热力学最稳定的构型;在簇中Ni-B键强于Ni-P键,且类金属B、P间存在近距离接触.     

原子簇NiBP稳定结构与成键性质的DFT研究

利用DFT方法在B3LYP/Lan12dz水平下对原子簇NiBP的单重态和三重态各种可能构型进行优化,计算结果表明:单重态有两个稳定构型,即具有Cs对称性的NiBP(1)(A)和Cv对称性的NiBP(1)(B);三重态也有两个稳定构型,即具有Cs对称性的NiBP(3)(A)和Cv对称性的NiBP(3)(D),原子簇NiBP(3)(A)是单、三重态中最稳定的构型;在原子簇中Ni,B,P原子间有强烈的相互作用.     

原子簇NiBP稳定结构与成键性质的DFT研究

利用DFF方法在B3LYP／Lanl2dz水平下对原子簇NiBP的单重态和三重态各种可能构型进行优化，计算结果表明：单重态有两个稳定构型，即具有Cs对称性的NiBP^[1](A)和Cv对称性的NiBP^[1](B)；三重态也有两个稳定构型，即具有Cs对称性的NiBP^[3](A)和Cv对称性的NiBP^[3](D)，原子簇NiBP^[3](A)是单、三重态中最稳定的构型；在原子簇中Ni，B，P原子间有强烈的相互作用．     

团簇Ni3CoP异构化反应

采用密度泛函理论方法,在B3LYP/lanl2dz水平下对团簇Ni3Co P进行量子化学计算,得到其优化构型。以过渡态理论为基础,对团簇Ni3Co P优化构型间的异构化反应进行化学动力学与化学热力学两方面的研究以探究团簇Ni3Co P最终可稳定存在的形式。结果表明:团簇Ni3Co P不同重态间的构型不存在转化;热力学稳定性较好的三重态构型异构化的趋势小,可单独稳定存在的可能性大,仅存在构型4(3)与3(3)间的可逆转化;单重态构型的异构化反应以构型4(1)为起点,可直接或间接(以构型2(1)、3(1)为中间体)地向构型1(1)进行转化且反应的限度较大,说明构型1(1)是团簇Ni3Co P单重态构型的主要存在形式。     

原子簇NiFeB2稳定结构与成键性质的DFT研究

利用DFT方法在B3LYP／Lan12dz水平下对原子簇NiFeB2的单、三重态的各种可能构型进行全参数优化．计算结果表明：单重态有三个稳定构型，三重态有四个稳定构型，且三重态比单重态稳定，这一点与NiFeB2具有磁性一致；在簇中Ni—B和Fe—B有强烈相互作用，Fe—B间作用力大于Ni—B间作用力；从热力学数据计算可知，原子簇NiFeB2比相应的原子簇NiB2和FeB2稳定．     

原子簇NiFeB2稳定结构与成键性质的DFT研究

利用DFT方法在B3LYP/Lan12dz水平下对原子簇NiFeB2的单、三重态的各种可能构型进行全参数优化.计算结果表明:单重态有三个稳定构型,三重态有四个稳定构型,且三重态比单重态稳定,这一点与NiFeB2具有磁性一致;在簇中Ni-B和Fe-B有强烈相互作用,Fe-B间作用力大于Ni-B间作用力;从热力学数据计算可知,原子簇NiFeB2比相应的原子簇NiB2和FeB2稳定.     

团簇Ti_3BP的结构稳定性及成键分析

为了解Ti-B-P体系的性质,使用密度泛函理论中B3LYP/Lan12方法对设计出的20种可能构型进行优化,得到6种稳定构型,三重态和单重态构型各3种。Ti-Ti键和Ti-B键存在一定的拮抗作用,Ti-P和B-P键之间存在明显的拮抗作用。不同键型对不同构型作用不同,B-P键在1(3)、1(1)、3(1)这三种构型中成反键,对构型稳定性不利,而在构型2(3)、3(3)、2(1)中,B-P键对团簇的稳定作用较Ti-P键强。重态对构型空间结构和键长键级都有影响,B-P键对三重态的稳定性贡献较大。Ti-P键和Ti-B键是团簇Ti3BP稳定性的主要贡献者。     

团簇Ni3CoP的结构和热力学稳定性

为深入了解非晶态合金Ni-Co-P的性质,以团簇Ni_3CoP为模型,基于密度泛函理论对其进行多方面的分析,包括稳定存在的构型、各构型所占比例、各种能量参数等以探究其稳定性,发现团簇Ni_3CoP除构型5(1)为戴帽三角锥型外,其余所有稳定存在的构型均为三角双锥型。单重态各构型和三重态各构型所占比例变化及各种能量参数的变化均比较平缓,但在单重态构型1(1)与三重态构型4(3)之间出现剧变点,团簇Ni_3CoP能稳定存在的临界能量约为-659.450 a.u。从能量学的角度看,多重度的改变对团簇Ni_3CoP构型的稳定性有较大影响,三重态构型的稳定性均好于单重态构型,构型1(3)所占比例最高,能量最低,结合能最大,吉布斯自由能变最小,是团簇Ni_3CoP最有可能稳定存在的形式。     

团簇Mo2S4的稳定结构和电子性质

根据密度泛函理论方法,在B3LYP/Lanl2dz水平下对已设计的团簇Mo_2S_4初始构型进行单重态和三重态的全参数优化计算,再排除同重态下相同构型及虚频不稳定构型后,得到10种优化后构型。各优化后构型的稳定程度为:1~((3))1~((1)) 2~((1))3~((1))4~((1))2~((3))3~((3))4~((3))5~((3))5~((1)),其中单重态的稳定性比三重态的稳定性好。团簇Mo_2S_4整体的电荷量和为0,呈电中性,各优化构型的电子流动性强弱与构型的空间结构有关,而与构型的自旋多重度无关,电子的流向主要由Mo原子流向S原子,Mo原子的5s、5p轨道与S原子的3p轨道是电子流动的主要贡献者。     

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.     

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     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the