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1.
用基团模型的3d^7离子在三角对称下的高阶微扰公式计算了CsMgCl3晶体中Co^2+杂质中心的g因子g∥,g⊥和超精细结构常数A∥和A⊥。计算中,不仅考虑了基态和激发态间的组态相互作用效应,而且考虑了3d^7离子d轨道与配体p轨道之间的共价效应,与这两种效应相关的参数可由所研究晶体的光谱和结构数据得到。在考虑了键长与键角的微弱畸变后,理论计算值与实验观测值符合较好。  相似文献   

2.
由于Cu0.5Zr2(PO4)3晶体具有良好的离子传导能力、催化特性、较低的热膨胀性,对它的研究引起了广泛的关注.本文引入平均共价因子N,并结合晶体结构数据给出了3d^9离子在晶场D4h下的g因子公式,利用该公式并结合Cu0.5Zr2(PO4)3晶体的具体结构数据对Cu0.5Zr2(PO4)3晶体中CU^2 中心的EPRg因子进行了理论分析计算,所得到的结果与实验值基本吻合.  相似文献   

3.
采用赵敏光等的μkα模型,在强场图象中建立了3d^8电子组态的多重态计算公式,利用高阶微挠公式推导出顺磁g因数的计算解析表达式,并在能量矩阵、g因数与掺杂真实晶体结构常数之间建立起关联公式.将此模型应用于KMgF3:Ni^2+晶体,计算其d—d跃迁光谱和EPR谱并与实验数据对比,发现KMgF3晶体在掺入Ni^2+后其结构应发生同向延伸变化,畸变量△R=0.004nm,计算结果与实验值符合较好.  相似文献   

4.
在一些四配位四面体的晶体中,过渡金属络离子(MLx)^n-往往具有较强的共价性和各向异性的EPRg因子,在晶体场理论基础上,研究了晶体NH4F以及Cs2ZnCl4中掺杂Cu^2 离子基态b2g的EPRg因子,理论计算与实验结果符合好。  相似文献   

5.
用分子轨道理论推导了3d^3离子在立方晶体场中的哈密顿矩阵,并计算了V^2+在ZnS中的吸收光谱.与其他近似方法相比较,该计算结果与实验符合得好,表明V^2+在ZnS中,共价因素和Racah参量A的贡献是很大的.理论计算出的一条近红外谱线有待实验的进一步检验.  相似文献   

6.
Co2+离子在CsMgCl3晶体中的g因子和超精细结构常数研究   总被引:1,自引:1,他引:0  
用基团模型的3d7离子在三角对称下的高阶微扰公式计算了CsMgCl3晶体中Co2+杂质中心的g因子g∥,g⊥和超精细结构常数A∥和A⊥.计算中,不仅考虑了基态和激发态间的组态相互作用效应,而且考虑了3d7离子d轨道与配体p轨道之间的共价效应,与这两种效应相关的参数可由所研究晶体的光谱和结构数据得到.在考虑了键长与键角的微弱畸变后,理论计算值与实验观测值符合较好.  相似文献   

7.
本文引入平均共价因子模型及有效电荷,计算了绿柱石晶体中的Fe^2+离子的d—d跃迁,并和实验数据进行了详细的比较,对实验结果中吸收峰进行了识别.结果表明,实验与理论相符合.  相似文献   

8.
本文采用点电荷—电偶极子模型半经验地确定了非自由态Ni~(2 )离子3d 轨道的双-ζ径向波西数,并应用MO 理论求出共价因子.由非自由度和共价因子来描绘晶体化合物里客观存在的金属离子和配位体间的重迭效应和共价性,来体现Ni~(2 )离子3d 轨道径向波函数的自由态和非自由态的区别.应用非自由态Ni~(2 )离子3d 轨道径向波函数,不另外引进参数,从理论上统一地计算了CsNiCl_3等八个卤秦配位Ni~(2 )络合物晶体的电子吸收光谱、g 因子、有效磁矩、磁化率、ESR 零场分裂精细结构常数等物理性质.计算结果与实验结果比较,92%符合较好,8%差一些.本文还从总结卤素配位Ni~( 2)离子络合物的吸收光谱中的~3A_(2g)(~3F)→′Eg(′D)谱带位置分布的实验结果入手,根据理论计算对晶体NiBr_2、CsNiI_3、NiI_2的吸收光谱中。~3A_(2g)(~3F)→′Eg(′D)谱带的位置提出自己的看法.  相似文献   

9.
用分子轨道近似推导了3d过渡金属离子在四面体晶体中轨道角动量和旋-轨耦合矩阵,同时得到了这些矩阵元与3d离子在纯晶体场近似下的矩阵之间的关系。通过以上矩阵元和关系可以很容易地计算3d离子在四面体晶体中的旋-轨、自旋-自旋和塞曼作用矩阵。这些旋-轨、自旋、自旋和塞曼作用矩阵对研究3d离子在四面体共价晶体中(尤其是半导体中)的超精细光谱、塞曼和交换分裂、电子顺磁共振参数、磁化强度、磁比热、磁化率等都是有用的。另外,还讨论了八面体和四面体对称下的配体轨道,以及3d离子和配体间的重迭积分。  相似文献   

10.
分别用平均共价因子和双共价因子模型研究了Cr~(4+):Ca_2GeO_4晶体的光谱,研究结果表明:平均共价因子模型下,计算值与实验值相差甚远;而双共价因子模型下的计算值与实验数据符合得很好.这说明传统的平均共价因子模型不能很好地解释Cr~(4+):Ca_2GeO_4晶体的光谱,而双共价因子模型能改进平均共价因子的不足,更好地解释Cr~(4+):Ca_2GeO_4晶体的光谱.  相似文献   

11.
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.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
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.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
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.  相似文献   

14.
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.  相似文献   

15.
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。  相似文献   

16.
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.  相似文献   

17.
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.  相似文献   

18.
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-  相似文献   

19.
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-  相似文献   

20.
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  相似文献   

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