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31.
运用自回归模型和SPSS软件从专利申请受理量、授权量、国内生产总值和人均国内生产总值四个指标中选出授权量和人均国内生产总值两个统计变量,根据统计数据分析两者之间的相关性,从模型计算结果可知两者存在较好的相关性;授权量对人均国内生产总值的贡献率为3.3%;模型不仅通过了一阶自相关性检验,有效解决了一阶自相关性问题,而且可有效预测我国人均国内生产总值。 相似文献
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Genetic analysis of fruit shape traits at different maturation stages in sponge gourd 总被引:5,自引:0,他引:5
The fruit shape is important quantitative trait closely related to the fruit quality. However, the genetic model of fruit shapes has not been proposed. Therefore, in the present study, analysis of genetic effects for fruit shape traits (fruit length and fruit perimeter) in sponge gourd was conducted by employing a developmental genetic model including fruit direct effects and maternal effects. Analysis approaches of unconditional and conditional variances were applied to evaluate the genetic behavior of fruit shape traits at economical and physiological maturation times. The results of variance analysis indicated that fruit length and fruit perimeter were simultaneously affected by fruit direct genetic effects and maternal effects. Fruit direct genetic effects were relatively more important for fruit shape traits at whole developmental period. The gene expression was most active at the economical maturation stage (1-12 d after flowering) for two shape traits, and the activation of gene was mostly due to direct dominance effects at physiological maturation stage (13-60 datter flowering). The coefficients due to different genetic effects, as well as the phenotypic correlation coefficients, varied significantly between fruit shape traits themselves at various maturation stages. The results showed that it was relatively easy to improve fruit shape traits for industrial purpose by carefully selecting the parents at economical maturation stage instead of that at physiological maturation stage. 相似文献
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探索高校实验室大型仪器设备管理新模式 总被引:4,自引:0,他引:4
高等学校大型仪器设备是从事教学、科研的重要条件和基本手段,是学校综合实力的体现。随着现代科学技术的迅猛发展,知识在经济发展中起到越来越重要的作用,使得高校大型仪器设备的管理显得尤为重要。结合工作实践,以及对目前高校实验室大型仪器设备管理及使用现状的分析,提出了加强高校大型仪器设备管理,提高大型仪器设备使用效率的若干措施。 相似文献
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管训贵 《山东教育学院学报》2011,26(5):117-118
设l,l1,l2,…,ls为任意整数,n为正整数,n1,n2,…,ns为任意非负整数.用初等数论方法证明了:如果k满足k=(4l+2)^3-Пi=1^s(4li+1)^2ni或k=(4l+3)^3-2^2nПi=1^s(4li+1)^2ni,则Mordell方程y^2=x^3+k无整数解. 相似文献
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Rechargeable magnesium batteries have received extensive attention as the Mg anodes possess twice the volumetric capacity of their lithium counterparts and are dendrite-free. However, Mg anodes suffer from surface passivation film in most glyme-based conventional electrolytes, leading to irreversible plating/stripping behavior of Mg. Here we report a facile and safe method to obtain a modified Mg metal anode with a Sn-based artificial layer via ion-exchange and alloying reactions. In the artificial coating layer, Mg2Sn alloy composites offer a channel for fast ion transport and insulating MgCl2/SnCl2 bestows the necessary potential gradient to prevent deposition on the surface. Significant improved ion conductivity of the solid electrolyte interfaces and decreased overpotential of Mg symmetric cells in Mg(TFSI)2/DME electrolyte are obtained. The coated Mg anodes can sustain a stable plating/stripping process over 4000 cycles at a high current density of 6 mA cm−2. This finding provides an avenue to facilitate fast ion diffusion kinetics of Mg metal anodes in conventional electrolytes. 相似文献