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1.
共线性在多元二次多项式回归模型中的危害及其处理方法   总被引:1,自引:0,他引:1  
廖森  王建设  陈超球 《广西科学》2003,10(2):101-103
以1个均匀设计应用的实例为对象,回归分析得到2个多元二次多项式方程,(1)Y=0.084826+0.23179X3—0.050286X2X3+0.028422X1X3—0.0013962X2X2;(2)Y=0.062320+0.2511X3—0.0600X3X3+0.02347X1X3。对这2个方程进行线性变换处理后,用SPSS软件包进行共线性诊断分析,得出方程(1)第4项和第2项存在强烈的共线性关系,共线性的存在使方程的预测变得不可靠;方程(2)没有共线性存在,可以正确指导科研工作。  相似文献   

2.
设φ:S→2^Y是非空凸集S包含X上的集值映射.如果存在λ0∈(0,1)使得λ0φ(X1)+(1-λ0)φ(X2)-φ(λ0X1+(1-λ0)X2)∈K,任意X1,2∈S那么T:={λ∈[0,1]:λφ(X1)+(1-λ)φ(X2)-φ(λX1+(1-λ)X2)∈K,任意X1,X2∈S}在[0,1]上稠密.  相似文献   

3.
为了探讨城镇建设用地的规划预测值与实际需求量的一致性,利用宜昌市1996-2004 年土地利用变更数据和社会经济统计资料进行了关联度分析,并结合该市国民经济和社会发展的中、长期规划目标,预测了2010-2020 年城镇建设用地的需求量.结果表明,城镇人口、固定资产投资总额和工业总产值等3个因素是驱动城镇建设用地增长的主要因子,其权重分别为0.404、0.316和0.280,预测到2010、2015和2020年,比规划基期(2004年)累积增加城镇建设用地面积742.36、1 673.12和2 857.43 hm2,其预测结果可为制定宜昌市城镇建设规划提供依据.  相似文献   

4.
树莓组织培养与快繁技术研究   总被引:1,自引:0,他引:1  
以树莓的顶芽和茎段为外植体进行了离体培养,筛选出最佳培养基:(1)腋芽诱导培养基为MS+6-BA0.5+TDZ0.3+NAA0.1;(2)试管苗增殖培养基为MS+6-BA0.5+TDZ0.1+NAA0.1;(3)生根培养基为MS+NAA0.4。  相似文献   

5.
分子电距矢量用于氯代苯类化合物毒性的预测   总被引:1,自引:0,他引:1  
通过对18个氯苯类化合物的分子电距矢量(MEDV)与其分子毒性关系进行关联,建立多元线性回归方程:-lgIC50=3.3377+3.2080v1+1.1453v2—0.5353v3—0.0571v6+0.3118v8,R为0.9420.随后采用留一法(LOO)交叉检验(CV)、内部模型验证法对其进行了验证,结果表明,该模型具有良好的稳定性和预测能力,在一定程度上阐明了氯苯类化合物与其分子电性距离矢量之间的关系.  相似文献   

6.
研究了两种来自昆嵛山萱草属(Hemerocallis)植物的染色体数目、核型,结果表明:黄花莱(H.citrina)的体细胞中期染色体核型为2n=2X=22=16m+4sm+2T。核型不对称系数为58.9%,染色体相对长度组成为2n=2X=22=6L+10M1+6S。染色体总体积为105.39μm^3;对于北萱草(Hesculenta),以上各项则分别为2n=2X=22=20m+2T、53.8%、2n=2X=22=4L+2M2+14M1+2S和99.43μm^3.同时对染色体的性状进行了巢式方差分析,表明居群内个体间、细胞间染色体的形态和大小具有一定程度的变异。且居群内的变异主要来自于个体间.  相似文献   

7.
丽格海棠的组织培养与快速繁殖研究   总被引:9,自引:0,他引:9  
以丽格海棠的茎状、叶柄、叶片为外植体进行组织培养。最佳培养基:(1)诱导培养基MS+6-BA4.0mg/L(单位下同)+IBA1.0;(2)增殖培养基MS+6-BA0.5+IAA0.2;(3)生根培养基MS+NAA0.2.生根壮苗培养50d左右,经移栽,成活率达92%左右。  相似文献   

8.
以LiTi2(PO4)3为基,用分析纯原料经高温固相反应(~900℃)制得一系列锂快离子导体材料Li1+2x+2yAlxMgyTi2-x-ySixP3-xO12(以下简称Ti—Mg—Lisicon).系统的合成温度随x和y的增大而降低.应用交流阻抗技术测定的电导率数据结果表明x=0.1,y=0.1的合成物室温电导率最好为1.31×10^-4S/cm,而673K时x=0.1,y=0.3的合成物的电导率最大,为2.93×10^-2S/cm.X射线衍射分析结果表明在x=0.1,y≤0.7;x=0.2,y≤0.6的组成范围内均得到空间群为R3C的合成物.  相似文献   

9.
Li3V2(PO4)3掺镍的性能研究   总被引:2,自引:0,他引:2  
摘要:采用溶胶凝胶法制备了锂离子电池正极材料Li3+xNixV2-x(PO4)3(x=0、0.05、0.10、0.20).通过XRD和SEM图谱对材料的结构及表面形貌进行了表征,结果表明Li3+xNixV2-x(PO4)3与Li3V2(PO4)3具有相同的结构,均属单斜晶系P2 1/n,掺杂后样品的颗粒随着Ni含量的增加而变大.循环伏安和充放电测试表明,随着Ni含量的增加,Li3+xNixV2-x(PO4)3的充放电容量降低,循环性能也变差,说明掺杂后样品的电化学性能变差.  相似文献   

10.
采用固相反应方法制备了系列Znce共掺杂Bao.2Sr0.8TiO3陶瓷材料,用X射线衍射(XRD)、扫描电子显微镜(SEM)和变温变频介电谱方法,对它们的微观结构和复介电常数进行了测量.结果表明,Zn^2+、Ce^4+的掺入,没有改变陶瓷试样的晶相结构,形成了均匀的固溶体.在1Hz测得的介电性能结果表明,随着Ce^4+掺杂量的增加,介电常数实部ε′逐渐增大,介电损耗tan占逐渐减小,介电常数峰明显减弱,并有逐渐变宽的趋势,呈现明显的相变弥散效应特征.当掺杂量Zn^2+为0.03864mol,C^4+为0.06mol时,陶瓷试样的介电损耗最小,为1.75×10^-3(1Hz).  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.
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   

14.
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   

15.
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   

16.
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   

17.
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   

18.
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   

19.
<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   

20.
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