基于CA和LS-SVM的TE过程多模型建模

针对TE化工过程高度非线性、复杂性的特点,本文提出了一种基于相关分析和最小二乘支持向量机对TE过程进行多模型建模方法,以提高模型性能。首先对TE过程采用相关分析法划分为3个子系统,对每个子系统分别采用基于C-均值聚类的最小二乘支持向量机建模和基于k均值聚类的最小二乘支持向量机多模型建模。实验表明,基于K-均值聚类的多模型建模能简化计算、提高模型精度、并且能更好的预测模型输出。     

阵列相关系数比对法在中药鉴别中的应用研究

中药材红外光谱具有“指纹”性,通过对红外特征吸收谱图的比对可达到区分和鉴别药材的目的。该研究用Visual Basic 6.0设计了中药材红外光谱阵列相关系数比对软件,建立了300多种中药药材的红外光谱数据库,将未知药材的红外光谱与数据库中药材的红外光谱进行比对,它能依11个波段两光谱相关系数的大小自动找到与库中最相似的光谱的药材,从而达到鉴别未知药材的目的。研究结果表明：在光谱数据库所包含的药材范围内,指定阵列相关系数的阈值,抓住特征波段光谱的比对,可避开CO₂和H₂O等外界因素对谱图的干扰,使比对结果准确可靠。该法有望成为中药材快速鉴别的一种常规手段。     

Ground-state correlation energy of counterions at a charged planar wall: Gibbs-Bogoliubov lower-bound approach

Recent simulation results imply the lowering of the ground-state correlation energy per counterion at a charged planar wall, compared with that of the 2D and 3D one-component plasma systems. Our aim is to correctly evaluate the ground-state energy of strongly-coupled counterion systems by considering a quasi-2D bound state where bound counterions are confined to a layer of molecular thickness. We use a variational approach based on the Gibbs-Bogoliubov inequality for the lower-bound free energy so that the liquid-state theory can be incorporated into the formulations. The soft mean spherical approximation demonstrates that the lowered ground-state energy can be reproduced by the obtained analytical form of a quasi-2D bound state.     

汉中青少年头发5种元素的分析

用原子吸收光谱法测定了陕西汉中地区２６６例健康男女青少年头发中５种金属元素的含量。并进行了直线相关回分析。结果表明,青春期女性头发中的铜,锌、铁、钙,镁５种元素的含量皆明显高于同年龄段男性;Ｃａ与Ｍｇ、Ｚｎ、Ｆｅ元素含量之间有不同程度的相关。     

Removal of phosphate from aqueous solution by zeolite synthesized from fly ash

Fifteen Chinese fly ashes were converted hydrothermally into zeolites, and phosphate immobilization capacity (PIC) of the synthesized zeolites and the corresponding raw fly ashes were determined using an initial phosphate concentration of 1000 mg/L. Results showed that there was a remarkable increase in PIC (from 1.2 to 7.6 times) following the synthesis process. Fractionation of immobilized phosphorus indicated that Fe+Al-P increased most significantly and consistently among all the phosphorus fractions following the conversion of fly ash to zeolite. The PIC and Ca+Mg-P were closely related to Ca content (with r values of 0.9683 and 0.9651, respectively) rather than Mg content (with r values of 0.3920 and 0.3212, respectively). The r values of PIC and Fe+Al-P with Fe content (with r values of 0.4686 and 0.6385, respectively) were higher than those with Al content (with r values of -0.7857 and -0.3770, respectively). Although calcium and iron components were mainly involved in phosphate immobilization, there was no significant change of Ca and Fe content following the conversion of fly ash to zeolite. Increase in dissociated Fe(2)O(3) and specific surface area probably accounted for the enhancement in PIC of synthesized zeolites compared with corresponding fly ashes. The PIC value of zeolites showed a significant correlation with dissociated Fe(2)O(3) (r=0.6186). The specific surface area increased 26.0-89.4 times as a result of the conversion of fly ash to zeolite. The maximum removal of phosphate occurred within different pH ranges for zeolites which were synthesized from high, medium and low calcium fly ashes and this behavior was explained by the reaction of phosphate with calcium and iron components.     

竞争性自适应重加权算法和相关系数法提取特征波长检测番茄叶片真菌病害

基于竞争性自适应重加权算法(CARS)和相关系数法(CA)特征波长选择方法,提出了利用可见-近红外高光谱成像技术检测番茄叶片灰霉病的方法。首先获取380～1 023 nm波段范围内80个染病和80个健康番茄叶片的高光谱图像,然后提取染病和健康叶片感兴趣区域(ROI)的光谱反射率值,作为番茄叶片灰霉病鉴别模型的输入来建立支持向量机(SVM)鉴别模型,训练集和验证集的鉴别率都是100%。研究进一步通过CARS和CA提取特征波长,分别得到5个(554, 694, 696, 738和880 nm)和4个(527, 555, 571和633 nm)特征波长,然后分别建立CARS-SVM和CA-SVM鉴别模型。结果显示,CARS-SVM模型中训练集和验证集的鉴别率都是100%,CA-SVM模型中训练集和验证集的鉴别率分别是91.59%和92.45%。以上结果说明了从可见-近红外高光谱图像中提取的光谱反射率值用于检测番茄叶片的灰霉病是可行的。     

Imaging and correlation used for guided laser lithotripsy

High-speed imaging of phenomena akin to laser lithotripsy is performed. A new method for guiding laser light for the stone destruction is proposed. This is based on a combination of signals obtained from the correlation of fluorescent and ballistic images.     

730 eV电子碰撞He原子(e, 2e)电离的三重微分截面

考虑初态He原子电子间的关联效应、末态敲出电子与剩余束缚电子间的关联效应和末态屏蔽效应, 计算和分析了在共面、大能量损失和小动量转移这一特殊几何条件下730eV电子离化He原子的三重微分截面. 所得结果与Stevenson等人的相对实验数据和CCC理论计算结果进行比较发现: 所得到的理论曲线能够反映实验数据给出的三重微分截面的结构特征.     

近红外光谱监测体外循环手术中脑组织氧合状况的研究

体外循环手术中,为防止因脑氧供需失衡导致脑缺氧,就要实时监测患者局部脑组织的氧合状况,以根据其变化调整生理参数或采取应急手段。用该研究小组自行研制的近红外仪器(使用一个双波长的近红外光源和两个近红外检测器)监测心脏手术中患者的脑氧,可以求出局部脑组织血红蛋白浓度的变化,并根据稳态空间分辨光谱(SRS)算法求出局部脑组织的氧饱和度(rSO₂)。体外循环中用监护仪监测患者的混合静脉血氧饱和度(SvO₂)等生理参数。测得的血红蛋白浓度变化容易受到干扰,而rSO₂的抗干扰性能较好。rSO₂在整个手术过程中都可以监测到,而SvO₂只能在体外循环过程中监测到。多数患者rSO₂和SvO₂存在正向相关性,但二者的相关系数并不很高。这是因为SvO₂是大静脉的血氧饱和度,而测得的rSO₂反映局部脑组织的氧合状况,二者的生理意义不同。实验结果表明,体外循环手术中rSO₂可以反映患者脑组织氧合状况的变化,而仅仅监测SvO₂是不够的。     

Calculations of Two and Three-Body Correlation Entropies at the Freezing Points of Soft-Core Fluids: Effect of the Softness on the Correlation Entropy

Two and three-body correlation entropies of model fluids, in which particles interact each other through the 4th, 6th, 9th and 12th-inverse-power potentials, were calculated from their atomic configurations obtained by molecular dynamics simulations at their freezing points. Besides the soft-core fluid model with the inverse-power potentials, hard-sphere and classical one-component plasma models were employed to provide a comparison with the entropies of the soft-core model. The correlation entropies were plotted as a function of the softness of the potential. These values were also compared with the excess entropies of the hard-sphere and the one-component plasma models at their freezing points.