基于时间序列的铁路客流量预测及票额优化配置

铁路客流量受多因素影响,其时序特征明显,因此,基于平稳时间序列构建客流数据预测模型及单车次多区间票额分配模型,有利于掌握客流动态变化,改善铁路运营压力。实现特征数据抽取系统开发,进行累加、循环、筛选算法等数据预处理;运用多因子方差分析评价多种因素的显著相关性影响,通过ARMA模型进行短时旅客客流量预测,进行模型优化并检验,同时,基于线性规划构建客座率最大化的区间票额分配优化模型。     

一类创新型权证的数学模型

为了解决中国证券市场股权分置这一体制性矛盾,一些上市公司推出了派发创新型权证的股改方案,该创新型权证将股票与权证相捆绑,从而不能假定股票收益呈现几何布朗运动.为了对该创新型权证定价,利用研究信用风险的结构化方法,以公司资产作为基本变量,对有担保与无担保的情况分别计算出该创新型权证的定价公式,对不同市场变量对于创新型权证价格的影响作了理论和数值分析.     

库车北部构造侏罗系煤层井壁稳定对策研究

为解决塔里木盆地库车北部构造带侏罗系煤系地层井段井壁稳定问题,采用X射线衍射、扫描电镜等方法对煤岩理化性能和微观结构进行分析,明确了煤系地层井壁失稳机理;建立考虑多割理面影响的煤层井段坍塌压力模型,评价了煤系地层地质力学参数和井壁稳定性,并优化了煤系层段井眼轨迹;根据煤岩微观结构特征,开展了钻井液封堵材料优选,形成煤层段水平井井壁稳定对策。结果表明,煤系地层主要为力学失稳,推荐煤层沿最大主应力方位、井斜45°～80°钻井,钻井液密度1.70～1.74 g/cm³,钻井液封堵复配体系为3%磺化沥青+3%乳化沥青+3%超细钙;应用发现煤系层段定向钻井无复杂事故,煤层斜井段井壁稳定防治效果好。研究成果对塔里木盆地库车北部构造带侏罗系油气安全高效开发具有重要指导作用。     

Richard Lewontin and the “complications of linkage”

During the 1960s and 1970s population geneticists pushed beyond models of single genes to grapple with the effect on evolution of multiple genes associated by linkage. The resulting models of multiple interacting loci suggested that blocks of genes, maybe even entire chromosomes or the genome itself, should be treated as a unit. In this context, Richard Lewontin wrote his famous 1974 book The Genetic Basis of Evolutionary Change, which concludes with an argument for considering the entire genome as the unit of selection as a result of linkage. Why did Lewontin and others devote so much intellectual energy to the “complications of linkage” in the 1960s and 1970s? We argue that this attention to linkage should be understood in the context of research on chromosomal inversions and co-adapted gene complexes that occupied mid-century evolutionary genetics. For Lewontin, the complications of linkage were an extension of this chromosomal focus expressed in the new language of models for linkage disequilibrium.     

P6m2-ReB3的高压物性研究

本文利用赝势平面波法计算了ReB3的三种晶体结构P(6)m2,P63/mmc及P3ml的结构属性.研究发现P(6)m2-ReB3是ReB3的基态相位.我们首次系统研究了高压下P(6)m2-ReB3的弹性常数、弹性各向异性、各种弹性模量及波速度等弹性特性,并且预测了P(6)m2-ReB3的韧脆性.此外,通过准谐德拜模型,我们还分析了P(6)m2-ReB3结构的德拜温度、标准化体积、体积模量、热膨胀系数及热容与压力或温度的依赖关系.