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混沌多项式新求解及其在板料成形性容差预测中的应用 被引量:5
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作者 韦东来 崔振山 陈军 《机械工程学报》 EI CAS CSCD 北大核心 2009年第8期261-265,共5页
利用单项式容积法的积分点,通过回归求解混沌多项式(Polynomial chaos expansion,PCE)系数,提出一种构造PCE的高效方法。该方法解决了概率配点法和随机响应面法的两大问题:①当采用加权余量法构造PCE时,须要用高斯积分法求数值解,但是... 利用单项式容积法的积分点,通过回归求解混沌多项式(Polynomial chaos expansion,PCE)系数,提出一种构造PCE的高效方法。该方法解决了概率配点法和随机响应面法的两大问题:①当采用加权余量法构造PCE时,须要用高斯积分法求数值解,但是高斯积分点个数随变量维数增加而呈幂次递增,而单项式容积法积分点的数量比较接近PCE系数的个数,所以能够有效降低原始模型的计算或模拟次数;②因为概率配点法和随机响应面法只抽取了部分高斯点,不同的取法可能会产生不同的结果。由于单项式容积法只需要少量积分点,故可以全部抽取,不存在取样差异的问题。通过具有精确解的数学算例的计算对比,结果表明该方法不但显著减少模拟次数而且精度与MonteCarlo方法相当。将该方法应用于行李箱后盖外板成形质量的容差预测,验证了该法在工程应用中的可行性。 展开更多
关键词 混沌多项式 单项式积法 概率配点法 随机响应面法 板料成形 数值模拟 容差预测
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The ionic parachor and predicting properties of amino acid ionic liquid homologues of 1-alkyl-3-methylimidazolium glycine
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作者 TONG Jing HONG Mei +3 位作者 WANG PanPan GUAN Wei FANG DaWei YANG JiaZhen 《Science China Chemistry》 SCIE EI CAS 2012年第7期1330-1337,共8页
The amino acid ionic liquids (AAILs) [C3mim][Gly] (1-propyl-3-methylimidazolium glycine) and [C4mim][Gly] (l-butyl-3- methylimidazolium glycine) have been prepared by the neutralization method and characterized ... The amino acid ionic liquids (AAILs) [C3mim][Gly] (1-propyl-3-methylimidazolium glycine) and [C4mim][Gly] (l-butyl-3- methylimidazolium glycine) have been prepared by the neutralization method and characterized by IH NMR spectroscopy and differential scanning calorimetry (DSC). The values of their density, surface tension and refractive index were measured at (298.15 ± 0.05) K. Since the AAILs can form strong hydrogen bonds with water, small amounts of water are difficult to remove from the AAILs by common methods. In order to eliminate the effect of the impurity water, the standard addition method (SAM) was applied to these measurements. A new concept which is called the ionic parachor has been put forward. The [Cn mim]+ cations were treated as a group of reference ions and the individual values of their ionic parachor were evaluated in terms of an extrathermodynamic assumption. Then, using the values of the ionic parachor of reference ions, the parachor, surface tension y and refractive index no of the ionic liquids investigated in this work were estimated. The estimated values correlate quite well with the corresponding experimental values. 展开更多
关键词 ionic liquids ionic parachor GLYCINE density surface tension extrathermodynamic assumption
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