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研究和探讨斐波那契数F_n标准分解式中因子23的指数与其下标n之间的内在联系.同时证明,斐波那契数F_n下标n的分解式中因数23的指数与24的指数是共同确定F_n标准分解式中因子23的指数的重要因素. 相似文献
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聊城市春季鸟类分布的边缘效应 总被引:1,自引:0,他引:1
报道4、5月间聊城市南区鸟类的多样性状况,记录到鸟类36种,分属于8目23科,群落物种多样性指数和均匀性指数较大者为郊区,其次为田间,市区最小,作为群落交错区,郊区的边缘效应非常显著。 相似文献
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菲厌氧降解对细菌和古细菌群落的影响 总被引:1,自引:0,他引:1
利用TRFLP技术研究了受垃圾渗滤液污染的地下沉积物中细菌和古细菌群落在菲厌氧降解前后的变化。结果表明:细菌群落在生物降解过程中变化很大,物种丰度及Shannon-Weiner指数分别由15和2.39增加到23和2.88;古细菌群落在生物降解过程中变化较小,物种丰度及Shannon-Weiner指数变化不大。 相似文献
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在MAPGIS技术支持下,采用综合指数模型,将各影响因素按其权重进行空间代数叠加,根据叠加的结果并结合综合评估指数的大小将甘肃省的矿山地质环境分为3级区.其中:严重区23个、较严重区22个、一般区1个,分别占全省总面积的2.731%,7.380%和89.889%. 相似文献
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于四勇 《甘肃联合大学学报(自然科学版)》2015,29(2):29-31
简单连通图的Randic’指数是化学图论中一个重要的拓扑指数,其在化学领域中有着广泛的研究及应用.我们给出了一个具有n个顶点的二树图的最大和最小的Randic’指数,即2n-4/2(n-1)+1/n-1≤R(G)≤n/2-11/4+23/3+6/3+2/2同时当二树图达到这两个界限时,它的图也被刻画了出来. 相似文献
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为了解吉林省西部地区近23年景观分布规律及其驱动机制,利用景观格局指数对吉林省西部1990年、2000年、2013年三期的土地利用类型进行分析,对吉林省西部土地利用类型和土地景观指数进行分析,深入探究吉林省西部景观格局分布特征,并探讨了造成研究区景观格局变化的驱动因子.结果表明:吉林省西部土地利用类型中旱田面积最大,为... 相似文献
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用RAPD技术对尼科巴弓背蚁5个巢穴的DNA样品进行分析,15个RAPD引物共检测到61个位点,每个引物产生2~7个位点,其中23个为多态位点,占37.70%,Nei's基因多样性指数H为0.1220,Shannon多态性信息指数I为0.1858。地域之间遗传相似性系数S的变化在0.8515~0.9485,遗传距离指数D的变化为0.0516~0.1603,用NTSYSpc 2.10软件包中的UPGMA法进行聚类分析。结果表明,5个不同巢穴间的尼科巴弓背蚁亲缘关系与地理距离相吻合。 相似文献
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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
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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
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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
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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
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Miao Maosheng 《华南师范大学学报(自然科学版)》2014,(6)
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
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Yang Weitao 《华南师范大学学报(自然科学版)》2014,46(6):137-138
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
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Bernard Kirtman 《华南师范大学学报(自然科学版)》2014,(6)
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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Michael Springborg 《华南师范大学学报(自然科学版)》2014,(6):136
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 相似文献
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Zhu Chaoyuan 《华南师范大学学报(自然科学版)》2014,46(6):140-140
Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of 相似文献
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《上海师范大学学报(自然科学版)》2014,(5):550
<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with 相似文献